/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.support.design.widget;
import android.content.Context;
import android.content.res.Resources;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Rect;
import android.graphics.drawable.ColorDrawable;
import android.graphics.drawable.Drawable;
import android.os.Build;
import android.os.Parcel;
import android.os.Parcelable;
import android.os.SystemClock;
import android.support.design.R;
import android.support.v4.content.ContextCompat;
import android.support.v4.view.GravityCompat;
import android.support.v4.view.MotionEventCompat;
import android.support.v4.view.NestedScrollingParent;
import android.support.v4.view.NestedScrollingParentHelper;
import android.support.v4.view.ViewCompat;
import android.support.v4.view.WindowInsetsCompat;
import android.text.TextUtils;
import android.util.AttributeSet;
import android.util.Log;
import android.util.SparseArray;
import android.view.Gravity;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.ViewParent;
import android.view.ViewTreeObserver;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.reflect.Constructor;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* CoordinatorLayout is a super-powered {@link android.widget.FrameLayout FrameLayout}.
*
* <p>CoordinatorLayout is intended for two primary use cases:</p>
* <ol>
* <li>As a top-level application decor or chrome layout</li>
* <li>As a container for a specific interaction with one or more child views</li>
* </ol>
*
* <p>By specifying {@link CoordinatorLayout.Behavior Behaviors} for child views of a
* CoordinatorLayout you can provide many different interactions within a single parent and those
* views can also interact with one another. View classes can specify a default behavior when
* used as a child of a CoordinatorLayout using the
* {@link CoordinatorLayout.DefaultBehavior DefaultBehavior} annotation.</p>
*
* <p>Behaviors may be used to implement a variety of interactions and additional layout
* modifications ranging from sliding drawers and panels to swipe-dismissable elements and buttons
* that stick to other elements as they move and animate.</p>
*
* <p>Children of a CoordinatorLayout may have an
* {@link CoordinatorLayout.LayoutParams#setAnchorId(int) anchor}. This view id must correspond
* to an arbitrary descendant of the CoordinatorLayout, but it may not be the anchored child itself
* or a descendant of the anchored child. This can be used to place floating views relative to
* other arbitrary content panes.</p>
*/
public class CoordinatorLayout extends ViewGroup implements NestedScrollingParent {
static final String TAG = "CoordinatorLayout";
static final String WIDGET_PACKAGE_NAME = CoordinatorLayout.class.getPackage().getName();
private static final int TYPE_ON_INTERCEPT = 0;
private static final int TYPE_ON_TOUCH = 1;
static {
if (Build.VERSION.SDK_INT >= 21) {
TOP_SORTED_CHILDREN_COMPARATOR = new ViewElevationComparator();
INSETS_HELPER = new CoordinatorLayoutInsetsHelperLollipop();
} else {
TOP_SORTED_CHILDREN_COMPARATOR = null;
INSETS_HELPER = null;
}
}
static final Class<?>[] CONSTRUCTOR_PARAMS = new Class<?>[] {
Context.class,
AttributeSet.class
};
static final ThreadLocal<Map<String, Constructor<Behavior>>> sConstructors =
new ThreadLocal<>();
final Comparator<View> mLayoutDependencyComparator = new Comparator<View>() {
@Override
public int compare(View lhs, View rhs) {
if (lhs == rhs) {
return 0;
} else if (((LayoutParams) lhs.getLayoutParams()).dependsOn(
CoordinatorLayout.this, lhs, rhs)) {
return 1;
} else if (((LayoutParams) rhs.getLayoutParams()).dependsOn(
CoordinatorLayout.this, rhs, lhs)) {
return -1;
} else {
return 0;
}
}
};
static final Comparator<View> TOP_SORTED_CHILDREN_COMPARATOR;
static final CoordinatorLayoutInsetsHelper INSETS_HELPER;
private final List<View> mDependencySortedChildren = new ArrayList<View>();
private final List<View> mTempList1 = new ArrayList<>();
private final List<View> mTempDependenciesList = new ArrayList<>();
private final Rect mTempRect1 = new Rect();
private final Rect mTempRect2 = new Rect();
private final Rect mTempRect3 = new Rect();
private final int[] mTempIntPair = new int[2];
private Paint mScrimPaint;
private boolean mIsAttachedToWindow;
private int[] mKeylines;
private View mBehaviorTouchView;
private View mNestedScrollingDirectChild;
private View mNestedScrollingTarget;
private OnPreDrawListener mOnPreDrawListener;
private boolean mNeedsPreDrawListener;
private WindowInsetsCompat mLastInsets;
private boolean mDrawStatusBarBackground;
private Drawable mStatusBarBackground;
private OnHierarchyChangeListener mOnHierarchyChangeListener;
private final NestedScrollingParentHelper mNestedScrollingParentHelper =
new NestedScrollingParentHelper(this);
public CoordinatorLayout(Context context) {
this(context, null);
}
public CoordinatorLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public CoordinatorLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
final TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.CoordinatorLayout,
defStyleAttr, R.style.Widget_Design_CoordinatorLayout);
final int keylineArrayRes = a.getResourceId(R.styleable.CoordinatorLayout_keylines, 0);
if (keylineArrayRes != 0) {
final Resources res = context.getResources();
mKeylines = res.getIntArray(keylineArrayRes);
final float density = res.getDisplayMetrics().density;
final int count = mKeylines.length;
for (int i = 0; i < count; i++) {
mKeylines[i] *= density;
}
}
mStatusBarBackground = a.getDrawable(R.styleable.CoordinatorLayout_statusBarBackground);
a.recycle();
if (INSETS_HELPER != null) {
INSETS_HELPER.setupForWindowInsets(this, new ApplyInsetsListener());
}
super.setOnHierarchyChangeListener(new HierarchyChangeListener());
}
@Override
public void setOnHierarchyChangeListener(OnHierarchyChangeListener onHierarchyChangeListener) {
mOnHierarchyChangeListener = onHierarchyChangeListener;
}
@Override
public void onAttachedToWindow() {
super.onAttachedToWindow();
resetTouchBehaviors();
if (mNeedsPreDrawListener) {
if (mOnPreDrawListener == null) {
mOnPreDrawListener = new OnPreDrawListener();
}
final ViewTreeObserver vto = getViewTreeObserver();
vto.addOnPreDrawListener(mOnPreDrawListener);
}
if (mLastInsets == null && ViewCompat.getFitsSystemWindows(this)) {
// We're set to fitSystemWindows but we haven't had any insets yet...
// We should request a new dispatch of window insets
ViewCompat.requestApplyInsets(this);
}
mIsAttachedToWindow = true;
}
@Override
public void onDetachedFromWindow() {
super.onDetachedFromWindow();
resetTouchBehaviors();
if (mNeedsPreDrawListener && mOnPreDrawListener != null) {
final ViewTreeObserver vto = getViewTreeObserver();
vto.removeOnPreDrawListener(mOnPreDrawListener);
}
if (mNestedScrollingTarget != null) {
onStopNestedScroll(mNestedScrollingTarget);
}
mIsAttachedToWindow = false;
}
/**
* Set a drawable to draw in the insets area for the status bar.
* Note that this will only be activated if this DrawerLayout fitsSystemWindows.
*
* @param bg Background drawable to draw behind the status bar
*/
public void setStatusBarBackground(Drawable bg) {
mStatusBarBackground = bg;
invalidate();
}
/**
* Gets the drawable used to draw in the insets area for the status bar.
*
* @return The status bar background drawable, or null if none set
*/
public Drawable getStatusBarBackground() {
return mStatusBarBackground;
}
/**
* Set a drawable to draw in the insets area for the status bar.
* Note that this will only be activated if this DrawerLayout fitsSystemWindows.
*
* @param resId Resource id of a background drawable to draw behind the status bar
*/
public void setStatusBarBackgroundResource(int resId) {
setStatusBarBackground(resId != 0 ? ContextCompat.getDrawable(getContext(), resId) : null);
}
/**
* Set a drawable to draw in the insets area for the status bar.
* Note that this will only be activated if this DrawerLayout fitsSystemWindows.
*
* @param color Color to use as a background drawable to draw behind the status bar
* in 0xAARRGGBB format.
*/
public void setStatusBarBackgroundColor(int color) {
setStatusBarBackground(new ColorDrawable(color));
}
private void setWindowInsets(WindowInsetsCompat insets) {
if (mLastInsets != insets) {
mLastInsets = insets;
mDrawStatusBarBackground = insets != null && insets.getSystemWindowInsetTop() > 0;
setWillNotDraw(!mDrawStatusBarBackground && getBackground() == null);
dispatchChildApplyWindowInsets(insets);
requestLayout();
}
}
/**
* Reset all Behavior-related tracking records either to clean up or in preparation
* for a new event stream. This should be called when attached or detached from a window,
* in response to an UP or CANCEL event, when intercept is request-disallowed
* and similar cases where an event stream in progress will be aborted.
*/
private void resetTouchBehaviors() {
if (mBehaviorTouchView != null) {
final Behavior b = ((LayoutParams) mBehaviorTouchView.getLayoutParams()).getBehavior();
if (b != null) {
final long now = SystemClock.uptimeMillis();
final MotionEvent cancelEvent = MotionEvent.obtain(now, now,
MotionEvent.ACTION_CANCEL, 0.0f, 0.0f, 0);
b.onTouchEvent(this, mBehaviorTouchView, cancelEvent);
cancelEvent.recycle();
}
mBehaviorTouchView = null;
}
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View child = getChildAt(i);
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
lp.resetTouchBehaviorTracking();
}
}
/**
* Populate a list with the current child views, sorted such that the topmost views
* in z-order are at the front of the list. Useful for hit testing and event dispatch.
*/
private void getTopSortedChildren(List<View> out) {
out.clear();
final boolean useCustomOrder = isChildrenDrawingOrderEnabled();
final int childCount = getChildCount();
for (int i = childCount - 1; i >= 0; i--) {
final int childIndex = useCustomOrder ? getChildDrawingOrder(childCount, i) : i;
final View child = getChildAt(childIndex);
out.add(child);
}
if (TOP_SORTED_CHILDREN_COMPARATOR != null) {
Collections.sort(out, TOP_SORTED_CHILDREN_COMPARATOR);
}
}
private boolean performIntercept(MotionEvent ev, final int type) {
boolean intercepted = false;
boolean newBlock = false;
MotionEvent cancelEvent = null;
final int action = MotionEventCompat.getActionMasked(ev);
final List<View> topmostChildList = mTempList1;
getTopSortedChildren(topmostChildList);
// Let topmost child views inspect first
final int childCount = topmostChildList.size();
for (int i = 0; i < childCount; i++) {
final View child = topmostChildList.get(i);
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final Behavior b = lp.getBehavior();
if ((intercepted || newBlock) && action != MotionEvent.ACTION_DOWN) {
// Cancel all behaviors beneath the one that intercepted.
// If the event is "down" then we don't have anything to cancel yet.
if (b != null) {
if (cancelEvent != null) {
final long now = SystemClock.uptimeMillis();
cancelEvent = MotionEvent.obtain(now, now,
MotionEvent.ACTION_CANCEL, 0.0f, 0.0f, 0);
}
switch (type) {
case TYPE_ON_INTERCEPT:
b.onInterceptTouchEvent(this, child, cancelEvent);
break;
case TYPE_ON_TOUCH:
b.onTouchEvent(this, child, cancelEvent);
break;
}
}
continue;
}
if (!intercepted && b != null) {
switch (type) {
case TYPE_ON_INTERCEPT:
intercepted = b.onInterceptTouchEvent(this, child, ev);
break;
case TYPE_ON_TOUCH:
intercepted = b.onTouchEvent(this, child, ev);
break;
}
if (intercepted) {
mBehaviorTouchView = child;
}
}
// Don't keep going if we're not allowing interaction below this.
// Setting newBlock will make sure we cancel the rest of the behaviors.
final boolean wasBlocking = lp.didBlockInteraction();
final boolean isBlocking = lp.isBlockingInteractionBelow(this, child);
newBlock = isBlocking && !wasBlocking;
if (isBlocking && !newBlock) {
// Stop here since we don't have anything more to cancel - we already did
// when the behavior first started blocking things below this point.
break;
}
}
topmostChildList.clear();
return intercepted;
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
MotionEvent cancelEvent = null;
final int action = MotionEventCompat.getActionMasked(ev);
// Make sure we reset in case we had missed a previous important event.
if (action == MotionEvent.ACTION_DOWN) {
resetTouchBehaviors();
}
final boolean intercepted = performIntercept(ev, TYPE_ON_INTERCEPT);
if (cancelEvent != null) {
cancelEvent.recycle();
}
if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_CANCEL) {
resetTouchBehaviors();
}
return intercepted;
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
boolean handled = false;
boolean cancelSuper = false;
MotionEvent cancelEvent = null;
final int action = MotionEventCompat.getActionMasked(ev);
if (mBehaviorTouchView != null || (cancelSuper = performIntercept(ev, TYPE_ON_TOUCH))) {
// Safe since performIntercept guarantees that
// mBehaviorTouchView != null if it returns true
final LayoutParams lp = (LayoutParams) mBehaviorTouchView.getLayoutParams();
final Behavior b = lp.getBehavior();
if (b != null) {
handled = b.onTouchEvent(this, mBehaviorTouchView, ev);
}
}
// Keep the super implementation correct
if (mBehaviorTouchView == null) {
handled |= super.onTouchEvent(ev);
} else if (cancelSuper) {
if (cancelEvent != null) {
final long now = SystemClock.uptimeMillis();
cancelEvent = MotionEvent.obtain(now, now,
MotionEvent.ACTION_CANCEL, 0.0f, 0.0f, 0);
}
super.onTouchEvent(cancelEvent);
}
if (!handled && action == MotionEvent.ACTION_DOWN) {
}
if (cancelEvent != null) {
cancelEvent.recycle();
}
if (action == MotionEvent.ACTION_UP || action == MotionEvent.ACTION_CANCEL) {
resetTouchBehaviors();
}
return handled;
}
@Override
public void requestDisallowInterceptTouchEvent(boolean disallowIntercept) {
super.requestDisallowInterceptTouchEvent(disallowIntercept);
if (disallowIntercept) {
resetTouchBehaviors();
}
}
private int getKeyline(int index) {
if (mKeylines == null) {
Log.e(TAG, "No keylines defined for " + this + " - attempted index lookup " + index);
return 0;
}
if (index < 0 || index >= mKeylines.length) {
Log.e(TAG, "Keyline index " + index + " out of range for " + this);
return 0;
}
return mKeylines[index];
}
static Behavior parseBehavior(Context context, AttributeSet attrs, String name) {
if (TextUtils.isEmpty(name)) {
return null;
}
final String fullName;
if (name.startsWith(".")) {
// Relative to the app package. Prepend the app package name.
fullName = context.getPackageName() + name;
} else if (name.indexOf('.') >= 0) {
// Fully qualified package name.
fullName = name;
} else {
// Assume stock behavior in this package.
fullName = WIDGET_PACKAGE_NAME + '.' + name;
}
try {
Map<String, Constructor<Behavior>> constructors = sConstructors.get();
if (constructors == null) {
constructors = new HashMap<>();
sConstructors.set(constructors);
}
Constructor<Behavior> c = constructors.get(fullName);
if (c == null) {
final Class<Behavior> clazz = (Class<Behavior>) Class.forName(fullName, true,
context.getClassLoader());
c = clazz.getConstructor(CONSTRUCTOR_PARAMS);
c.setAccessible(true);
constructors.put(fullName, c);
}
return c.newInstance(context, attrs);
} catch (Exception e) {
throw new RuntimeException("Could not inflate Behavior subclass " + fullName, e);
}
}
LayoutParams getResolvedLayoutParams(View child) {
final LayoutParams result = (LayoutParams) child.getLayoutParams();
if (!result.mBehaviorResolved) {
Class<?> childClass = child.getClass();
DefaultBehavior defaultBehavior = null;
while (childClass != null &&
(defaultBehavior = childClass.getAnnotation(DefaultBehavior.class)) == null) {
childClass = childClass.getSuperclass();
}
if (defaultBehavior != null) {
try {
result.setBehavior(defaultBehavior.value().newInstance());
} catch (Exception e) {
Log.e(TAG, "Default behavior class " + defaultBehavior.value().getName() +
" could not be instantiated. Did you forget a default constructor?", e);
}
}
result.mBehaviorResolved = true;
}
return result;
}
private void prepareChildren() {
final int childCount = getChildCount();
boolean resortRequired = mDependencySortedChildren.size() != childCount;
for (int i = 0; i < childCount; i++) {
final View child = getChildAt(i);
final LayoutParams lp = getResolvedLayoutParams(child);
if (!resortRequired && lp.isDirty(this, child)) {
resortRequired = true;
}
lp.findAnchorView(this, child);
}
if (resortRequired) {
mDependencySortedChildren.clear();
for (int i = 0; i < childCount; i++) {
mDependencySortedChildren.add(getChildAt(i));
}
Collections.sort(mDependencySortedChildren, mLayoutDependencyComparator);
}
}
/**
* Retrieve the transformed bounding rect of an arbitrary descendant view.
* This does not need to be a direct child.
*
* @param descendant descendant view to reference
* @param out rect to set to the bounds of the descendant view
*/
void getDescendantRect(View descendant, Rect out) {
ViewGroupUtils.getDescendantRect(this, descendant, out);
}
@Override
protected int getSuggestedMinimumWidth() {
return Math.max(super.getSuggestedMinimumWidth(), getPaddingLeft() + getPaddingRight());
}
@Override
protected int getSuggestedMinimumHeight() {
return Math.max(super.getSuggestedMinimumHeight(), getPaddingTop() + getPaddingBottom());
}
/**
* Called to measure each individual child view unless a
* {@link CoordinatorLayout.Behavior Behavior} is present. The Behavior may choose to delegate
* child measurement to this method.
*
* @param child the child to measure
* @param parentWidthMeasureSpec the width requirements for this view
* @param widthUsed extra space that has been used up by the parent
* horizontally (possibly by other children of the parent)
* @param parentHeightMeasureSpec the height requirements for this view
* @param heightUsed extra space that has been used up by the parent
* vertically (possibly by other children of the parent)
*/
public void onMeasureChild(View child, int parentWidthMeasureSpec, int widthUsed,
int parentHeightMeasureSpec, int heightUsed) {
measureChildWithMargins(child, parentWidthMeasureSpec, widthUsed,
parentHeightMeasureSpec, heightUsed);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
prepareChildren();
ensurePreDrawListener();
final int paddingLeft = getPaddingLeft();
final int paddingTop = getPaddingTop();
final int paddingRight = getPaddingRight();
final int paddingBottom = getPaddingBottom();
final int layoutDirection = ViewCompat.getLayoutDirection(this);
final boolean isRtl = layoutDirection == ViewCompat.LAYOUT_DIRECTION_RTL;
final int widthMode = MeasureSpec.getMode(widthMeasureSpec);
final int widthSize = MeasureSpec.getSize(widthMeasureSpec);
final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
final int heightSize = MeasureSpec.getSize(heightMeasureSpec);
final int widthPadding = paddingLeft + paddingRight;
final int heightPadding = paddingTop + paddingBottom;
int widthUsed = getSuggestedMinimumWidth();
int heightUsed = getSuggestedMinimumHeight();
int childState = 0;
final boolean applyInsets = mLastInsets != null && ViewCompat.getFitsSystemWindows(this);
final int childCount = mDependencySortedChildren.size();
for (int i = 0; i < childCount; i++) {
final View child = mDependencySortedChildren.get(i);
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
int keylineWidthUsed = 0;
if (lp.keyline >= 0 && widthMode != MeasureSpec.UNSPECIFIED) {
final int keylinePos = getKeyline(lp.keyline);
final int keylineGravity = GravityCompat.getAbsoluteGravity(
resolveKeylineGravity(lp.gravity), layoutDirection)
& Gravity.HORIZONTAL_GRAVITY_MASK;
if ((keylineGravity == Gravity.LEFT && !isRtl)
|| (keylineGravity == Gravity.RIGHT && isRtl)) {
keylineWidthUsed = Math.max(0, widthSize - paddingRight - keylinePos);
} else if ((keylineGravity == Gravity.RIGHT && !isRtl)
|| (keylineGravity == Gravity.LEFT && isRtl)) {
keylineWidthUsed = Math.max(0, keylinePos - paddingLeft);
}
}
int childWidthMeasureSpec = widthMeasureSpec;
int childHeightMeasureSpec = heightMeasureSpec;
if (applyInsets && !ViewCompat.getFitsSystemWindows(child)) {
// We're set to handle insets but this child isn't, so we will measure the
// child as if there are no insets
final int horizInsets = mLastInsets.getSystemWindowInsetLeft()
+ mLastInsets.getSystemWindowInsetRight();
final int vertInsets = mLastInsets.getSystemWindowInsetTop()
+ mLastInsets.getSystemWindowInsetBottom();
childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(
widthSize - horizInsets, widthMode);
childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(
heightSize - vertInsets, heightMode);
}
final Behavior b = lp.getBehavior();
if (b == null || !b.onMeasureChild(this, child, childWidthMeasureSpec, keylineWidthUsed,
childHeightMeasureSpec, 0)) {
onMeasureChild(child, childWidthMeasureSpec, keylineWidthUsed,
childHeightMeasureSpec, 0);
}
widthUsed = Math.max(widthUsed, widthPadding + child.getMeasuredWidth() +
lp.leftMargin + lp.rightMargin);
heightUsed = Math.max(heightUsed, heightPadding + child.getMeasuredHeight() +
lp.topMargin + lp.bottomMargin);
childState = ViewCompat.combineMeasuredStates(childState,
ViewCompat.getMeasuredState(child));
}
final int width = ViewCompat.resolveSizeAndState(widthUsed, widthMeasureSpec,
childState & ViewCompat.MEASURED_STATE_MASK);
final int height = ViewCompat.resolveSizeAndState(heightUsed, heightMeasureSpec,
childState << ViewCompat.MEASURED_HEIGHT_STATE_SHIFT);
setMeasuredDimension(width, height);
}
private void dispatchChildApplyWindowInsets(WindowInsetsCompat insets) {
if (insets.isConsumed()) {
return;
}
for (int i = 0, z = getChildCount(); i < z; i++) {
final View child = getChildAt(i);
if (ViewCompat.getFitsSystemWindows(child)) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final Behavior b = lp.getBehavior();
if (b != null) {
// If the view has a behavior, let it try first
insets = b.onApplyWindowInsets(this, child, insets);
if (insets.isConsumed()) {
// If it consumed the insets, break
break;
}
}
// Now let the view try and consume them
insets = ViewCompat.dispatchApplyWindowInsets(child, insets);
if (insets.isConsumed()) {
break;
}
}
}
}
/**
* Called to lay out each individual child view unless a
* {@link CoordinatorLayout.Behavior Behavior} is present. The Behavior may choose to
* delegate child measurement to this method.
*
* @param child child view to lay out
* @param layoutDirection the resolved layout direction for the CoordinatorLayout, such as
* {@link ViewCompat#LAYOUT_DIRECTION_LTR} or
* {@link ViewCompat#LAYOUT_DIRECTION_RTL}.
*/
public void onLayoutChild(View child, int layoutDirection) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
if (lp.checkAnchorChanged()) {
throw new IllegalStateException("An anchor may not be changed after CoordinatorLayout"
+ " measurement begins before layout is complete.");
}
if (lp.mAnchorView != null) {
layoutChildWithAnchor(child, lp.mAnchorView, layoutDirection);
} else if (lp.keyline >= 0) {
layoutChildWithKeyline(child, lp.keyline, layoutDirection);
} else {
layoutChild(child, layoutDirection);
}
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
final int layoutDirection = ViewCompat.getLayoutDirection(this);
final int childCount = mDependencySortedChildren.size();
for (int i = 0; i < childCount; i++) {
final View child = mDependencySortedChildren.get(i);
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final Behavior behavior = lp.getBehavior();
if (behavior == null || !behavior.onLayoutChild(this, child, layoutDirection)) {
onLayoutChild(child, layoutDirection);
}
}
}
@Override
public void onDraw(Canvas c) {
super.onDraw(c);
if (mDrawStatusBarBackground && mStatusBarBackground != null) {
final int inset = mLastInsets != null ? mLastInsets.getSystemWindowInsetTop() : 0;
if (inset > 0) {
mStatusBarBackground.setBounds(0, 0, getWidth(), inset);
mStatusBarBackground.draw(c);
}
}
}
/**
* Mark the last known child position rect for the given child view.
* This will be used when checking if a child view's position has changed between frames.
* The rect used here should be one returned by
* {@link #getChildRect(android.view.View, boolean, android.graphics.Rect)}, with translation
* disabled.
*
* @param child child view to set for
* @param r rect to set
*/
void recordLastChildRect(View child, Rect r) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
lp.setLastChildRect(r);
}
/**
* Get the last known child rect recorded by
* {@link #recordLastChildRect(android.view.View, android.graphics.Rect)}.
*
* @param child child view to retrieve from
* @param out rect to set to the outpur values
*/
void getLastChildRect(View child, Rect out) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
out.set(lp.getLastChildRect());
}
/**
* Get the position rect for the given child. If the child has currently requested layout
* or has a visibility of GONE.
*
* @param child child view to check
* @param transform true to include transformation in the output rect, false to
* only account for the base position
* @param out rect to set to the output values
*/
void getChildRect(View child, boolean transform, Rect out) {
if (child.isLayoutRequested() || child.getVisibility() == View.GONE) {
out.set(0, 0, 0, 0);
return;
}
if (transform) {
getDescendantRect(child, out);
} else {
out.set(child.getLeft(), child.getTop(), child.getRight(), child.getBottom());
}
}
/**
* Calculate the desired child rect relative to an anchor rect, respecting both
* gravity and anchorGravity.
*
* @param child child view to calculate a rect for
* @param layoutDirection the desired layout direction for the CoordinatorLayout
* @param anchorRect rect in CoordinatorLayout coordinates of the anchor view area
* @param out rect to set to the output values
*/
void getDesiredAnchoredChildRect(View child, int layoutDirection, Rect anchorRect, Rect out) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final int absGravity = GravityCompat.getAbsoluteGravity(
resolveAnchoredChildGravity(lp.gravity), layoutDirection);
final int absAnchorGravity = GravityCompat.getAbsoluteGravity(
resolveGravity(lp.anchorGravity),
layoutDirection);
final int hgrav = absGravity & Gravity.HORIZONTAL_GRAVITY_MASK;
final int vgrav = absGravity & Gravity.VERTICAL_GRAVITY_MASK;
final int anchorHgrav = absAnchorGravity & Gravity.HORIZONTAL_GRAVITY_MASK;
final int anchorVgrav = absAnchorGravity & Gravity.VERTICAL_GRAVITY_MASK;
final int childWidth = child.getMeasuredWidth();
final int childHeight = child.getMeasuredHeight();
int left;
int top;
// Align to the anchor. This puts us in an assumed right/bottom child view gravity.
// If this is not the case we will subtract out the appropriate portion of
// the child size below.
switch (anchorHgrav) {
default:
case Gravity.LEFT:
left = anchorRect.left;
break;
case Gravity.RIGHT:
left = anchorRect.right;
break;
case Gravity.CENTER_HORIZONTAL:
left = anchorRect.left + anchorRect.width() / 2;
break;
}
switch (anchorVgrav) {
default:
case Gravity.TOP:
top = anchorRect.top;
break;
case Gravity.BOTTOM:
top = anchorRect.bottom;
break;
case Gravity.CENTER_VERTICAL:
top = anchorRect.top + anchorRect.height() / 2;
break;
}
// Offset by the child view's gravity itself. The above assumed right/bottom gravity.
switch (hgrav) {
default:
case Gravity.LEFT:
left -= childWidth;
break;
case Gravity.RIGHT:
// Do nothing, we're already in position.
break;
case Gravity.CENTER_HORIZONTAL:
left -= childWidth / 2;
break;
}
switch (vgrav) {
default:
case Gravity.TOP:
top -= childHeight;
break;
case Gravity.BOTTOM:
// Do nothing, we're already in position.
break;
case Gravity.CENTER_VERTICAL:
top -= childHeight / 2;
break;
}
final int width = getWidth();
final int height = getHeight();
// Obey margins and padding
left = Math.max(getPaddingLeft() + lp.leftMargin,
Math.min(left,
width - getPaddingRight() - childWidth - lp.rightMargin));
top = Math.max(getPaddingTop() + lp.topMargin,
Math.min(top,
height - getPaddingBottom() - childHeight - lp.bottomMargin));
out.set(left, top, left + childWidth, top + childHeight);
}
/**
* CORE ASSUMPTION: anchor has been laid out by the time this is called for a given child view.
*
* @param child child to lay out
* @param anchor view to anchor child relative to; already laid out.
* @param layoutDirection ViewCompat constant for layout direction
*/
private void layoutChildWithAnchor(View child, View anchor, int layoutDirection) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final Rect anchorRect = mTempRect1;
final Rect childRect = mTempRect2;
getDescendantRect(anchor, anchorRect);
getDesiredAnchoredChildRect(child, layoutDirection, anchorRect, childRect);
child.layout(childRect.left, childRect.top, childRect.right, childRect.bottom);
}
/**
* Lay out a child view with respect to a keyline.
*
* <p>The keyline represents a horizontal offset from the unpadded starting edge of
* the CoordinatorLayout. The child's gravity will affect how it is positioned with
* respect to the keyline.</p>
*
* @param child child to lay out
* @param keyline offset from the starting edge in pixels of the keyline to align with
* @param layoutDirection ViewCompat constant for layout direction
*/
private void layoutChildWithKeyline(View child, int keyline, int layoutDirection) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final int absGravity = GravityCompat.getAbsoluteGravity(
resolveKeylineGravity(lp.gravity), layoutDirection);
final int hgrav = absGravity & Gravity.HORIZONTAL_GRAVITY_MASK;
final int vgrav = absGravity & Gravity.VERTICAL_GRAVITY_MASK;
final int width = getWidth();
final int height = getHeight();
final int childWidth = child.getMeasuredWidth();
final int childHeight = child.getMeasuredHeight();
if (layoutDirection == ViewCompat.LAYOUT_DIRECTION_RTL) {
keyline = width - keyline;
}
int left = getKeyline(keyline) - childWidth;
int top = 0;
switch (hgrav) {
default:
case Gravity.LEFT:
// Nothing to do.
break;
case Gravity.RIGHT:
left += childWidth;
break;
case Gravity.CENTER_HORIZONTAL:
left += childWidth / 2;
break;
}
switch (vgrav) {
default:
case Gravity.TOP:
// Do nothing, we're already in position.
break;
case Gravity.BOTTOM:
top += childHeight;
break;
case Gravity.CENTER_VERTICAL:
top += childHeight / 2;
break;
}
// Obey margins and padding
left = Math.max(getPaddingLeft() + lp.leftMargin,
Math.min(left,
width - getPaddingRight() - childWidth - lp.rightMargin));
top = Math.max(getPaddingTop() + lp.topMargin,
Math.min(top,
height - getPaddingBottom() - childHeight - lp.bottomMargin));
child.layout(left, top, left + childWidth, top + childHeight);
}
/**
* Lay out a child view with no special handling. This will position the child as
* if it were within a FrameLayout or similar simple frame.
*
* @param child child view to lay out
* @param layoutDirection ViewCompat constant for the desired layout direction
*/
private void layoutChild(View child, int layoutDirection) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final Rect parent = mTempRect1;
parent.set(getPaddingLeft() + lp.leftMargin,
getPaddingTop() + lp.topMargin,
getWidth() - getPaddingRight() - lp.rightMargin,
getHeight() - getPaddingBottom() - lp.bottomMargin);
if (mLastInsets != null && ViewCompat.getFitsSystemWindows(this)
&& !ViewCompat.getFitsSystemWindows(child)) {
// If we're set to handle insets but this child isn't, then it has been measured as
// if there are no insets. We need to lay it out to match.
parent.left += mLastInsets.getSystemWindowInsetLeft();
parent.top += mLastInsets.getSystemWindowInsetTop();
parent.right -= mLastInsets.getSystemWindowInsetRight();
parent.bottom -= mLastInsets.getSystemWindowInsetBottom();
}
final Rect out = mTempRect2;
GravityCompat.apply(resolveGravity(lp.gravity), child.getMeasuredWidth(),
child.getMeasuredHeight(), parent, out, layoutDirection);
child.layout(out.left, out.top, out.right, out.bottom);
}
/**
* Return the given gravity value or the default if the passed value is NO_GRAVITY.
* This should be used for children that are not anchored to another view or a keyline.
*/
private static int resolveGravity(int gravity) {
return gravity == Gravity.NO_GRAVITY ? GravityCompat.START | Gravity.TOP : gravity;
}
/**
* Return the given gravity value or the default if the passed value is NO_GRAVITY.
* This should be used for children that are positioned relative to a keyline.
*/
private static int resolveKeylineGravity(int gravity) {
return gravity == Gravity.NO_GRAVITY ? GravityCompat.END | Gravity.TOP : gravity;
}
/**
* Return the given gravity value or the default if the passed value is NO_GRAVITY.
* This should be used for children that are anchored to another view.
*/
private static int resolveAnchoredChildGravity(int gravity) {
return gravity == Gravity.NO_GRAVITY ? Gravity.CENTER : gravity;
}
@Override
protected boolean drawChild(Canvas canvas, View child, long drawingTime) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
if (lp.mBehavior != null && lp.mBehavior.getScrimOpacity(this, child) > 0.f) {
if (mScrimPaint == null) {
mScrimPaint = new Paint();
}
mScrimPaint.setColor(lp.mBehavior.getScrimColor(this, child));
// TODO: Set the clip appropriately to avoid unnecessary overdraw.
canvas.drawRect(getPaddingLeft(), getPaddingTop(),
getWidth() - getPaddingRight(), getHeight() - getPaddingBottom(), mScrimPaint);
}
return super.drawChild(canvas, child, drawingTime);
}
/**
* Dispatch any dependent view changes to the relevant {@link Behavior} instances.
*
* Usually run as part of the pre-draw step when at least one child view has a reported
* dependency on another view. This allows CoordinatorLayout to account for layout
* changes and animations that occur outside of the normal layout pass.
*
* It can also be ran as part of the nested scrolling dispatch to ensure that any offsetting
* is completed within the correct coordinate window.
*
* The offsetting behavior implemented here does not store the computed offset in
* the LayoutParams; instead it expects that the layout process will always reconstruct
* the proper positioning.
*
* @param fromNestedScroll true if this is being called from one of the nested scroll methods,
* false if run as part of the pre-draw step.
*/
void dispatchOnDependentViewChanged(final boolean fromNestedScroll) {
final int layoutDirection = ViewCompat.getLayoutDirection(this);
final int childCount = mDependencySortedChildren.size();
for (int i = 0; i < childCount; i++) {
final View child = mDependencySortedChildren.get(i);
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
// Check child views before for anchor
for (int j = 0; j < i; j++) {
final View checkChild = mDependencySortedChildren.get(j);
if (lp.mAnchorDirectChild == checkChild) {
offsetChildToAnchor(child, layoutDirection);
}
}
// Did it change? if not continue
final Rect oldRect = mTempRect1;
final Rect newRect = mTempRect2;
getLastChildRect(child, oldRect);
getChildRect(child, true, newRect);
if (oldRect.equals(newRect)) {
continue;
}
recordLastChildRect(child, newRect);
// Update any behavior-dependent views for the change
for (int j = i + 1; j < childCount; j++) {
final View checkChild = mDependencySortedChildren.get(j);
final LayoutParams checkLp = (LayoutParams) checkChild.getLayoutParams();
final Behavior b = checkLp.getBehavior();
if (b != null && b.layoutDependsOn(this, checkChild, child)) {
if (!fromNestedScroll && checkLp.getChangedAfterNestedScroll()) {
// If this is not from a nested scroll and we have already been changed
// from a nested scroll, skip the dispatch and reset the flag
checkLp.resetChangedAfterNestedScroll();
continue;
}
final boolean handled = b.onDependentViewChanged(this, checkChild, child);
if (fromNestedScroll) {
// If this is from a nested scroll, set the flag so that we may skip
// any resulting onPreDraw dispatch (if needed)
checkLp.setChangedAfterNestedScroll(handled);
}
}
}
}
}
void dispatchDependentViewRemoved(View removedChild) {
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View child = getChildAt(i);
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final Behavior b = lp.getBehavior();
if (b != null && b.layoutDependsOn(this, child, removedChild)) {
b.onDependentViewRemoved(this, child, removedChild);
}
}
}
/**
* Allows the caller to manually dispatch
* {@link Behavior#onDependentViewChanged(CoordinatorLayout, View, View)} to the associated
* {@link Behavior} instances of views which depend on the provided {@link View}.
*
* <p>You should not normally need to call this method as the it will be automatically done
* when the view has changed.
*
* @param view the View to find dependents of to dispatch the call.
*/
public void dispatchDependentViewsChanged(View view) {
final int childCount = mDependencySortedChildren.size();
boolean viewSeen = false;
for (int i = 0; i < childCount; i++) {
final View child = mDependencySortedChildren.get(i);
if (child == view) {
// We've seen our view, which means that any Views after this could be dependent
viewSeen = true;
continue;
}
if (viewSeen) {
CoordinatorLayout.LayoutParams lp = (CoordinatorLayout.LayoutParams)
child.getLayoutParams();
CoordinatorLayout.Behavior b = lp.getBehavior();
if (b != null && lp.dependsOn(this, child, view)) {
b.onDependentViewChanged(this, child, view);
}
}
}
}
/**
* Returns the list of views which the provided view depends on. Do not store this list as it's
* contents may not be valid beyond the caller.
*
* @param child the view to find dependencies for.
*
* @return the list of views which {@code child} depends on.
*/
public List<View> getDependencies(View child) {
// TODO The result of this is probably a good candidate for caching
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final List<View> list = mTempDependenciesList;
list.clear();
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View other = getChildAt(i);
if (other == child) {
continue;
}
if (lp.dependsOn(this, child, other)) {
list.add(other);
}
}
return list;
}
/**
* Add or remove the pre-draw listener as necessary.
*/
void ensurePreDrawListener() {
boolean hasDependencies = false;
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View child = getChildAt(i);
if (hasDependencies(child)) {
hasDependencies = true;
break;
}
}
if (hasDependencies != mNeedsPreDrawListener) {
if (hasDependencies) {
addPreDrawListener();
} else {
removePreDrawListener();
}
}
}
/**
* Check if the given child has any layout dependencies on other child views.
*/
boolean hasDependencies(View child) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
if (lp.mAnchorView != null) {
return true;
}
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View other = getChildAt(i);
if (other == child) {
continue;
}
if (lp.dependsOn(this, child, other)) {
return true;
}
}
return false;
}
/**
* Add the pre-draw listener if we're attached to a window and mark that we currently
* need it when attached.
*/
void addPreDrawListener() {
if (mIsAttachedToWindow) {
// Add the listener
if (mOnPreDrawListener == null) {
mOnPreDrawListener = new OnPreDrawListener();
}
final ViewTreeObserver vto = getViewTreeObserver();
vto.addOnPreDrawListener(mOnPreDrawListener);
}
// Record that we need the listener regardless of whether or not we're attached.
// We'll add the real listener when we become attached.
mNeedsPreDrawListener = true;
}
/**
* Remove the pre-draw listener if we're attached to a window and mark that we currently
* do not need it when attached.
*/
void removePreDrawListener() {
if (mIsAttachedToWindow) {
if (mOnPreDrawListener != null) {
final ViewTreeObserver vto = getViewTreeObserver();
vto.removeOnPreDrawListener(mOnPreDrawListener);
}
}
mNeedsPreDrawListener = false;
}
/**
* Adjust the child left, top, right, bottom rect to the correct anchor view position,
* respecting gravity and anchor gravity.
*
* Note that child translation properties are ignored in this process, allowing children
* to be animated away from their anchor. However, if the anchor view is animated,
* the child will be offset to match the anchor's translated position.
*/
void offsetChildToAnchor(View child, int layoutDirection) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
if (lp.mAnchorView != null) {
final Rect anchorRect = mTempRect1;
final Rect childRect = mTempRect2;
final Rect desiredChildRect = mTempRect3;
getDescendantRect(lp.mAnchorView, anchorRect);
getChildRect(child, false, childRect);
getDesiredAnchoredChildRect(child, layoutDirection, anchorRect, desiredChildRect);
final int dx = desiredChildRect.left - childRect.left;
final int dy = desiredChildRect.top - childRect.top;
if (dx != 0) {
child.offsetLeftAndRight(dx);
}
if (dy != 0) {
child.offsetTopAndBottom(dy);
}
if (dx != 0 || dy != 0) {
// If we have needed to move, make sure to notify the child's Behavior
final Behavior b = lp.getBehavior();
if (b != null) {
b.onDependentViewChanged(this, child, lp.mAnchorView);
}
}
}
}
/**
* Check if a given point in the CoordinatorLayout's coordinates are within the view bounds
* of the given direct child view.
*
* @param child child view to test
* @param x X coordinate to test, in the CoordinatorLayout's coordinate system
* @param y Y coordinate to test, in the CoordinatorLayout's coordinate system
* @return true if the point is within the child view's bounds, false otherwise
*/
public boolean isPointInChildBounds(View child, int x, int y) {
final Rect r = mTempRect1;
getDescendantRect(child, r);
return r.contains(x, y);
}
/**
* Check whether two views overlap each other. The views need to be descendants of this
* {@link CoordinatorLayout} in the view hierarchy.
*
* @param first first child view to test
* @param second second child view to test
* @return true if both views are visible and overlap each other
*/
public boolean doViewsOverlap(View first, View second) {
if (first.getVisibility() == VISIBLE && second.getVisibility() == VISIBLE) {
final Rect firstRect = mTempRect1;
getChildRect(first, first.getParent() != this, firstRect);
final Rect secondRect = mTempRect2;
getChildRect(second, second.getParent() != this, secondRect);
return !(firstRect.left > secondRect.right || firstRect.top > secondRect.bottom
|| firstRect.right < secondRect.left || firstRect.bottom < secondRect.top);
}
return false;
}
@Override
public LayoutParams generateLayoutParams(AttributeSet attrs) {
return new LayoutParams(getContext(), attrs);
}
@Override
protected LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
if (p instanceof LayoutParams) {
return new LayoutParams((LayoutParams) p);
} else if (p instanceof MarginLayoutParams) {
return new LayoutParams((MarginLayoutParams) p);
}
return new LayoutParams(p);
}
@Override
protected LayoutParams generateDefaultLayoutParams() {
return new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
}
@Override
protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
return p instanceof LayoutParams && super.checkLayoutParams(p);
}
public boolean onStartNestedScroll(View child, View target, int nestedScrollAxes) {
boolean handled = false;
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View view = getChildAt(i);
final LayoutParams lp = (LayoutParams) view.getLayoutParams();
final Behavior viewBehavior = lp.getBehavior();
if (viewBehavior != null) {
final boolean accepted = viewBehavior.onStartNestedScroll(this, view, child, target,
nestedScrollAxes);
handled |= accepted;
lp.acceptNestedScroll(accepted);
} else {
lp.acceptNestedScroll(false);
}
}
return handled;
}
public void onNestedScrollAccepted(View child, View target, int nestedScrollAxes) {
mNestedScrollingParentHelper.onNestedScrollAccepted(child, target, nestedScrollAxes);
mNestedScrollingDirectChild = child;
mNestedScrollingTarget = target;
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View view = getChildAt(i);
final LayoutParams lp = (LayoutParams) view.getLayoutParams();
if (!lp.isNestedScrollAccepted()) {
continue;
}
final Behavior viewBehavior = lp.getBehavior();
if (viewBehavior != null) {
viewBehavior.onNestedScrollAccepted(this, view, child, target, nestedScrollAxes);
}
}
}
public void onStopNestedScroll(View target) {
mNestedScrollingParentHelper.onStopNestedScroll(target);
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View view = getChildAt(i);
final LayoutParams lp = (LayoutParams) view.getLayoutParams();
if (!lp.isNestedScrollAccepted()) {
continue;
}
final Behavior viewBehavior = lp.getBehavior();
if (viewBehavior != null) {
viewBehavior.onStopNestedScroll(this, view, target);
}
lp.resetNestedScroll();
lp.resetChangedAfterNestedScroll();
}
mNestedScrollingDirectChild = null;
mNestedScrollingTarget = null;
}
public void onNestedScroll(View target, int dxConsumed, int dyConsumed,
int dxUnconsumed, int dyUnconsumed) {
final int childCount = getChildCount();
boolean accepted = false;
for (int i = 0; i < childCount; i++) {
final View view = getChildAt(i);
final LayoutParams lp = (LayoutParams) view.getLayoutParams();
if (!lp.isNestedScrollAccepted()) {
continue;
}
final Behavior viewBehavior = lp.getBehavior();
if (viewBehavior != null) {
viewBehavior.onNestedScroll(this, view, target, dxConsumed, dyConsumed,
dxUnconsumed, dyUnconsumed);
accepted = true;
}
}
if (accepted) {
dispatchOnDependentViewChanged(true);
}
}
public void onNestedPreScroll(View target, int dx, int dy, int[] consumed) {
int xConsumed = 0;
int yConsumed = 0;
boolean accepted = false;
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View view = getChildAt(i);
final LayoutParams lp = (LayoutParams) view.getLayoutParams();
if (!lp.isNestedScrollAccepted()) {
continue;
}
final Behavior viewBehavior = lp.getBehavior();
if (viewBehavior != null) {
mTempIntPair[0] = mTempIntPair[1] = 0;
viewBehavior.onNestedPreScroll(this, view, target, dx, dy, mTempIntPair);
xConsumed = dx > 0 ? Math.max(xConsumed, mTempIntPair[0])
: Math.min(xConsumed, mTempIntPair[0]);
yConsumed = dy > 0 ? Math.max(yConsumed, mTempIntPair[1])
: Math.min(yConsumed, mTempIntPair[1]);
accepted = true;
}
}
consumed[0] = xConsumed;
consumed[1] = yConsumed;
if (accepted) {
dispatchOnDependentViewChanged(true);
}
}
public boolean onNestedFling(View target, float velocityX, float velocityY, boolean consumed) {
boolean handled = false;
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View view = getChildAt(i);
final LayoutParams lp = (LayoutParams) view.getLayoutParams();
if (!lp.isNestedScrollAccepted()) {
continue;
}
final Behavior viewBehavior = lp.getBehavior();
if (viewBehavior != null) {
handled |= viewBehavior.onNestedFling(this, view, target, velocityX, velocityY,
consumed);
}
}
if (handled) {
dispatchOnDependentViewChanged(true);
}
return handled;
}
public boolean onNestedPreFling(View target, float velocityX, float velocityY) {
boolean handled = false;
final int childCount = getChildCount();
for (int i = 0; i < childCount; i++) {
final View view = getChildAt(i);
final LayoutParams lp = (LayoutParams) view.getLayoutParams();
if (!lp.isNestedScrollAccepted()) {
continue;
}
final Behavior viewBehavior = lp.getBehavior();
if (viewBehavior != null) {
handled |= viewBehavior.onNestedPreFling(this, view, target, velocityX, velocityY);
}
}
return handled;
}
public int getNestedScrollAxes() {
return mNestedScrollingParentHelper.getNestedScrollAxes();
}
class OnPreDrawListener implements ViewTreeObserver.OnPreDrawListener {
@Override
public boolean onPreDraw() {
dispatchOnDependentViewChanged(false);
return true;
}
}
/**
* Sorts child views with higher Z values to the beginning of a collection.
*/
static class ViewElevationComparator implements Comparator<View> {
@Override
public int compare(View lhs, View rhs) {
final float lz = ViewCompat.getZ(lhs);
final float rz = ViewCompat.getZ(rhs);
if (lz > rz) {
return -1;
} else if (lz < rz) {
return 1;
}
return 0;
}
}
/**
* Defines the default {@link Behavior} of a {@link View} class.
*
* <p>When writing a custom view, use this annotation to define the default behavior
* when used as a direct child of an {@link CoordinatorLayout}. The default behavior
* can be overridden using {@link LayoutParams#setBehavior}.</p>
*
* <p>Example: <code>@DefaultBehavior(MyBehavior.class)</code></p>
*/
@Retention(RetentionPolicy.RUNTIME)
public @interface DefaultBehavior {
Class<? extends Behavior> value();
}
/**
* Interaction behavior plugin for child views of {@link CoordinatorLayout}.
*
* <p>A Behavior implements one or more interactions that a user can take on a child view.
* These interactions may include drags, swipes, flings, or any other gestures.</p>
*
* @param <V> The View type that this Behavior operates on
*/
public static abstract class Behavior<V extends View> {
/**
* Default constructor for instantiating Behaviors.
*/
public Behavior() {
}
/**
* Default constructor for inflating Behaviors from layout. The Behavior will have
* the opportunity to parse specially defined layout parameters. These parameters will
* appear on the child view tag.
*
* @param context
* @param attrs
*/
public Behavior(Context context, AttributeSet attrs) {
}
/**
* Respond to CoordinatorLayout touch events before they are dispatched to child views.
*
* <p>Behaviors can use this to monitor inbound touch events until one decides to
* intercept the rest of the event stream to take an action on its associated child view.
* This method will return false until it detects the proper intercept conditions, then
* return true once those conditions have occurred.</p>
*
* <p>Once a Behavior intercepts touch events, the rest of the event stream will
* be sent to the {@link #onTouchEvent} method.</p>
*
* <p>The default implementation of this method always returns false.</p>
*
* @param parent the parent view currently receiving this touch event
* @param child the child view associated with this Behavior
* @param ev the MotionEvent describing the touch event being processed
* @return true if this Behavior would like to intercept and take over the event stream.
* The default always returns false.
*/
public boolean onInterceptTouchEvent(CoordinatorLayout parent, V child, MotionEvent ev) {
return false;
}
/**
* Respond to CoordinatorLayout touch events after this Behavior has started
* {@link #onInterceptTouchEvent intercepting} them.
*
* <p>Behaviors may intercept touch events in order to help the CoordinatorLayout
* manipulate its child views. For example, a Behavior may allow a user to drag a
* UI pane open or closed. This method should perform actual mutations of view
* layout state.</p>
*
* @param parent the parent view currently receiving this touch event
* @param child the child view associated with this Behavior
* @param ev the MotionEvent describing the touch event being processed
* @return true if this Behavior handled this touch event and would like to continue
* receiving events in this stream. The default always returns false.
*/
public boolean onTouchEvent(CoordinatorLayout parent, V child, MotionEvent ev) {
return false;
}
/**
* Supply a scrim color that will be painted behind the associated child view.
*
* <p>A scrim may be used to indicate that the other elements beneath it are not currently
* interactive or actionable, drawing user focus and attention to the views above the scrim.
* </p>
*
* <p>The default implementation returns {@link Color#BLACK}.</p>
*
* @param parent the parent view of the given child
* @param child the child view above the scrim
* @return the desired scrim color in 0xAARRGGBB format. The default return value is
* {@link Color#BLACK}.
* @see #getScrimOpacity(CoordinatorLayout, android.view.View)
*/
public final int getScrimColor(CoordinatorLayout parent, V child) {
return Color.BLACK;
}
/**
* Determine the current opacity of the scrim behind a given child view
*
* <p>A scrim may be used to indicate that the other elements beneath it are not currently
* interactive or actionable, drawing user focus and attention to the views above the scrim.
* </p>
*
* <p>The default implementation returns 0.0f.</p>
*
* @param parent the parent view of the given child
* @param child the child view above the scrim
* @return the desired scrim opacity from 0.0f to 1.0f. The default return value is 0.0f.
*/
public final float getScrimOpacity(CoordinatorLayout parent, V child) {
return 0.f;
}
/**
* Determine whether interaction with views behind the given child in the child order
* should be blocked.
*
* <p>The default implementation returns true if
* {@link #getScrimOpacity(CoordinatorLayout, android.view.View)} would return > 0.0f.</p>
*
* @param parent the parent view of the given child
* @param child the child view to test
* @return true if {@link #getScrimOpacity(CoordinatorLayout, android.view.View)} would
* return > 0.0f.
*/
public boolean blocksInteractionBelow(CoordinatorLayout parent, V child) {
return getScrimOpacity(parent, child) > 0.f;
}
/**
* Determine whether the supplied child view has another specific sibling view as a
* layout dependency.
*
* <p>This method will be called at least once in response to a layout request. If it
* returns true for a given child and dependency view pair, the parent CoordinatorLayout
* will:</p>
* <ol>
* <li>Always lay out this child after the dependent child is laid out, regardless
* of child order.</li>
* <li>Call {@link #onDependentViewChanged} when the dependency view's layout or
* position changes.</li>
* </ol>
*
* @param parent the parent view of the given child
* @param child the child view to test
* @param dependency the proposed dependency of child
* @return true if child's layout depends on the proposed dependency's layout,
* false otherwise
*
* @see #onDependentViewChanged(CoordinatorLayout, android.view.View, android.view.View)
*/
public boolean layoutDependsOn(CoordinatorLayout parent, V child, View dependency) {
return false;
}
/**
* Respond to a change in a child's dependent view
*
* <p>This method is called whenever a dependent view changes in size or position outside
* of the standard layout flow. A Behavior may use this method to appropriately update
* the child view in response.</p>
*
* <p>A view's dependency is determined by
* {@link #layoutDependsOn(CoordinatorLayout, android.view.View, android.view.View)} or
* if {@code child} has set another view as it's anchor.</p>
*
* <p>Note that if a Behavior changes the layout of a child via this method, it should
* also be able to reconstruct the correct position in
* {@link #onLayoutChild(CoordinatorLayout, android.view.View, int) onLayoutChild}.
* <code>onDependentViewChanged</code> will not be called during normal layout since
* the layout of each child view will always happen in dependency order.</p>
*
* <p>If the Behavior changes the child view's size or position, it should return true.
* The default implementation returns false.</p>
*
* @param parent the parent view of the given child
* @param child the child view to manipulate
* @param dependency the dependent view that changed
* @return true if the Behavior changed the child view's size or position, false otherwise
*/
public boolean onDependentViewChanged(CoordinatorLayout parent, V child, View dependency) {
return false;
}
/**
* Respond to a child's dependent view being removed.
*
* <p>This method is called after a dependent view has been removed from the parent.
* A Behavior may use this method to appropriately update the child view in response.</p>
*
* <p>A view's dependency is determined by
* {@link #layoutDependsOn(CoordinatorLayout, android.view.View, android.view.View)} or
* if {@code child} has set another view as it's anchor.</p>
*
* @param parent the parent view of the given child
* @param child the child view to manipulate
* @param dependency the dependent view that has been removed
*/
public void onDependentViewRemoved(CoordinatorLayout parent, V child, View dependency) {
}
/**
* Determine whether the given child view should be considered dirty.
*
* <p>If a property determined by the Behavior such as other dependent views would change,
* the Behavior should report a child view as dirty. This will prompt the CoordinatorLayout
* to re-query Behavior-determined properties as appropriate.</p>
*
* @param parent the parent view of the given child
* @param child the child view to check
* @return true if child is dirty
*/
public boolean isDirty(CoordinatorLayout parent, V child) {
return false;
}
/**
* Called when the parent CoordinatorLayout is about to measure the given child view.
*
* <p>This method can be used to perform custom or modified measurement of a child view
* in place of the default child measurement behavior. The Behavior's implementation
* can delegate to the standard CoordinatorLayout measurement behavior by calling
* {@link CoordinatorLayout#onMeasureChild(android.view.View, int, int, int, int)
* parent.onMeasureChild}.</p>
*
* @param parent the parent CoordinatorLayout
* @param child the child to measure
* @param parentWidthMeasureSpec the width requirements for this view
* @param widthUsed extra space that has been used up by the parent
* horizontally (possibly by other children of the parent)
* @param parentHeightMeasureSpec the height requirements for this view
* @param heightUsed extra space that has been used up by the parent
* vertically (possibly by other children of the parent)
* @return true if the Behavior measured the child view, false if the CoordinatorLayout
* should perform its default measurement
*/
public boolean onMeasureChild(CoordinatorLayout parent, V child,
int parentWidthMeasureSpec, int widthUsed,
int parentHeightMeasureSpec, int heightUsed) {
return false;
}
/**
* Called when the parent CoordinatorLayout is about the lay out the given child view.
*
* <p>This method can be used to perform custom or modified layout of a child view
* in place of the default child layout behavior. The Behavior's implementation can
* delegate to the standard CoordinatorLayout measurement behavior by calling
* {@link CoordinatorLayout#onLayoutChild(android.view.View, int)
* parent.onMeasureChild}.</p>
*
* <p>If a Behavior implements
* {@link #onDependentViewChanged(CoordinatorLayout, android.view.View, android.view.View)}
* to change the position of a view in response to a dependent view changing, it
* should also implement <code>onLayoutChild</code> in such a way that respects those
* dependent views. <code>onLayoutChild</code> will always be called for a dependent view
* <em>after</em> its dependency has been laid out.</p>
*
* @param parent the parent CoordinatorLayout
* @param child child view to lay out
* @param layoutDirection the resolved layout direction for the CoordinatorLayout, such as
* {@link ViewCompat#LAYOUT_DIRECTION_LTR} or
* {@link ViewCompat#LAYOUT_DIRECTION_RTL}.
* @return true if the Behavior performed layout of the child view, false to request
* default layout behavior
*/
public boolean onLayoutChild(CoordinatorLayout parent, V child, int layoutDirection) {
return false;
}
// Utility methods for accessing child-specific, behavior-modifiable properties.
/**
* Associate a Behavior-specific tag object with the given child view.
* This object will be stored with the child view's LayoutParams.
*
* @param child child view to set tag with
* @param tag tag object to set
*/
public static void setTag(View child, Object tag) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
lp.mBehaviorTag = tag;
}
/**
* Get the behavior-specific tag object with the given child view.
* This object is stored with the child view's LayoutParams.
*
* @param child child view to get tag with
* @return the previously stored tag object
*/
public static Object getTag(View child) {
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
return lp.mBehaviorTag;
}
/**
* Called when a descendant of the CoordinatorLayout attempts to initiate a nested scroll.
*
* <p>Any Behavior associated with any direct child of the CoordinatorLayout may respond
* to this event and return true to indicate that the CoordinatorLayout should act as
* a nested scrolling parent for this scroll. Only Behaviors that return true from
* this method will receive subsequent nested scroll events.</p>
*
* @param coordinatorLayout the CoordinatorLayout parent of the view this Behavior is
* associated with
* @param child the child view of the CoordinatorLayout this Behavior is associated with
* @param directTargetChild the child view of the CoordinatorLayout that either is or
* contains the target of the nested scroll operation
* @param target the descendant view of the CoordinatorLayout initiating the nested scroll
* @param nestedScrollAxes the axes that this nested scroll applies to. See
* {@link ViewCompat#SCROLL_AXIS_HORIZONTAL},
* {@link ViewCompat#SCROLL_AXIS_VERTICAL}
* @return true if the Behavior wishes to accept this nested scroll
*
* @see NestedScrollingParent#onStartNestedScroll(View, View, int)
*/
public boolean onStartNestedScroll(CoordinatorLayout coordinatorLayout,
V child, View directTargetChild, View target, int nestedScrollAxes) {
return false;
}
/**
* Called when a nested scroll has been accepted by the CoordinatorLayout.
*
* <p>Any Behavior associated with any direct child of the CoordinatorLayout may elect
* to accept the nested scroll as part of {@link #onStartNestedScroll}. Each Behavior
* that returned true will receive subsequent nested scroll events for that nested scroll.
* </p>
*
* @param coordinatorLayout the CoordinatorLayout parent of the view this Behavior is
* associated with
* @param child the child view of the CoordinatorLayout this Behavior is associated with
* @param directTargetChild the child view of the CoordinatorLayout that either is or
* contains the target of the nested scroll operation
* @param target the descendant view of the CoordinatorLayout initiating the nested scroll
* @param nestedScrollAxes the axes that this nested scroll applies to. See
* {@link ViewCompat#SCROLL_AXIS_HORIZONTAL},
* {@link ViewCompat#SCROLL_AXIS_VERTICAL}
*
* @see NestedScrollingParent#onNestedScrollAccepted(View, View, int)
*/
public void onNestedScrollAccepted(CoordinatorLayout coordinatorLayout, V child,
View directTargetChild, View target, int nestedScrollAxes) {
// Do nothing
}
/**
* Called when a nested scroll has ended.
*
* <p>Any Behavior associated with any direct child of the CoordinatorLayout may elect
* to accept the nested scroll as part of {@link #onStartNestedScroll}. Each Behavior
* that returned true will receive subsequent nested scroll events for that nested scroll.
* </p>
*
* <p><code>onStopNestedScroll</code> marks the end of a single nested scroll event
* sequence. This is a good place to clean up any state related to the nested scroll.
* </p>
*
* @param coordinatorLayout the CoordinatorLayout parent of the view this Behavior is
* associated with
* @param child the child view of the CoordinatorLayout this Behavior is associated with
* @param target the descendant view of the CoordinatorLayout that initiated
* the nested scroll
*
* @see NestedScrollingParent#onStopNestedScroll(View)
*/
public void onStopNestedScroll(CoordinatorLayout coordinatorLayout, V child, View target) {
// Do nothing
}
/**
* Called when a nested scroll in progress has updated and the target has scrolled or
* attempted to scroll.
*
* <p>Any Behavior associated with the direct child of the CoordinatorLayout may elect
* to accept the nested scroll as part of {@link #onStartNestedScroll}. Each Behavior
* that returned true will receive subsequent nested scroll events for that nested scroll.
* </p>
*
* <p><code>onNestedScroll</code> is called each time the nested scroll is updated by the
* nested scrolling child, with both consumed and unconsumed components of the scroll
* supplied in pixels. <em>Each Behavior responding to the nested scroll will receive the
* same values.</em>
* </p>
*
* @param coordinatorLayout the CoordinatorLayout parent of the view this Behavior is
* associated with
* @param child the child view of the CoordinatorLayout this Behavior is associated with
* @param target the descendant view of the CoordinatorLayout performing the nested scroll
* @param dxConsumed horizontal pixels consumed by the target's own scrolling operation
* @param dyConsumed vertical pixels consumed by the target's own scrolling operation
* @param dxUnconsumed horizontal pixels not consumed by the target's own scrolling
* operation, but requested by the user
* @param dyUnconsumed vertical pixels not consumed by the target's own scrolling operation,
* but requested by the user
*
* @see NestedScrollingParent#onNestedScroll(View, int, int, int, int)
*/
public void onNestedScroll(CoordinatorLayout coordinatorLayout, V child, View target,
int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed) {
// Do nothing
}
/**
* Called when a nested scroll in progress is about to update, before the target has
* consumed any of the scrolled distance.
*
* <p>Any Behavior associated with the direct child of the CoordinatorLayout may elect
* to accept the nested scroll as part of {@link #onStartNestedScroll}. Each Behavior
* that returned true will receive subsequent nested scroll events for that nested scroll.
* </p>
*
* <p><code>onNestedPreScroll</code> is called each time the nested scroll is updated
* by the nested scrolling child, before the nested scrolling child has consumed the scroll
* distance itself. <em>Each Behavior responding to the nested scroll will receive the
* same values.</em> The CoordinatorLayout will report as consumed the maximum number
* of pixels in either direction that any Behavior responding to the nested scroll reported
* as consumed.</p>
*
* @param coordinatorLayout the CoordinatorLayout parent of the view this Behavior is
* associated with
* @param child the child view of the CoordinatorLayout this Behavior is associated with
* @param target the descendant view of the CoordinatorLayout performing the nested scroll
* @param dx the raw horizontal number of pixels that the user attempted to scroll
* @param dy the raw vertical number of pixels that the user attempted to scroll
* @param consumed out parameter. consumed[0] should be set to the distance of dx that
* was consumed, consumed[1] should be set to the distance of dy that
* was consumed
*
* @see NestedScrollingParent#onNestedPreScroll(View, int, int, int[])
*/
public void onNestedPreScroll(CoordinatorLayout coordinatorLayout, V child, View target,
int dx, int dy, int[] consumed) {
// Do nothing
}
/**
* Called when a nested scrolling child is starting a fling or an action that would
* be a fling.
*
* <p>Any Behavior associated with the direct child of the CoordinatorLayout may elect
* to accept the nested scroll as part of {@link #onStartNestedScroll}. Each Behavior
* that returned true will receive subsequent nested scroll events for that nested scroll.
* </p>
*
* <p><code>onNestedFling</code> is called when the current nested scrolling child view
* detects the proper conditions for a fling. It reports if the child itself consumed
* the fling. If it did not, the child is expected to show some sort of overscroll
* indication. This method should return true if it consumes the fling, so that a child
* that did not itself take an action in response can choose not to show an overfling
* indication.</p>
*
* @param coordinatorLayout the CoordinatorLayout parent of the view this Behavior is
* associated with
* @param child the child view of the CoordinatorLayout this Behavior is associated with
* @param target the descendant view of the CoordinatorLayout performing the nested scroll
* @param velocityX horizontal velocity of the attempted fling
* @param velocityY vertical velocity of the attempted fling
* @param consumed true if the nested child view consumed the fling
* @return true if the Behavior consumed the fling
*
* @see NestedScrollingParent#onNestedFling(View, float, float, boolean)
*/
public boolean onNestedFling(CoordinatorLayout coordinatorLayout, V child, View target,
float velocityX, float velocityY, boolean consumed) {
return false;
}
/**
* Called when a nested scrolling child is about to start a fling.
*
* <p>Any Behavior associated with the direct child of the CoordinatorLayout may elect
* to accept the nested scroll as part of {@link #onStartNestedScroll}. Each Behavior
* that returned true will receive subsequent nested scroll events for that nested scroll.
* </p>
*
* <p><code>onNestedPreFling</code> is called when the current nested scrolling child view
* detects the proper conditions for a fling, but it has not acted on it yet. A
* Behavior can return true to indicate that it consumed the fling. If at least one
* Behavior returns true, the fling should not be acted upon by the child.</p>
*
* @param coordinatorLayout the CoordinatorLayout parent of the view this Behavior is
* associated with
* @param child the child view of the CoordinatorLayout this Behavior is associated with
* @param target the descendant view of the CoordinatorLayout performing the nested scroll
* @param velocityX horizontal velocity of the attempted fling
* @param velocityY vertical velocity of the attempted fling
* @return true if the Behavior consumed the fling
*
* @see NestedScrollingParent#onNestedPreFling(View, float, float)
*/
public boolean onNestedPreFling(CoordinatorLayout coordinatorLayout, V child, View target,
float velocityX, float velocityY) {
return false;
}
/**
* Called when the window insets have changed.
*
* <p>Any Behavior associated with the direct child of the CoordinatorLayout may elect
* to handle the window inset change on behalf of it's associated view.
* </p>
*
* @param coordinatorLayout the CoordinatorLayout parent of the view this Behavior is
* associated with
* @param child the child view of the CoordinatorLayout this Behavior is associated with
* @param insets the new window insets.
*
* @return The insets supplied, minus any insets that were consumed
*/
public WindowInsetsCompat onApplyWindowInsets(CoordinatorLayout coordinatorLayout,
V child, WindowInsetsCompat insets) {
return insets;
}
/**
* Hook allowing a behavior to re-apply a representation of its internal state that had
* previously been generated by {@link #onSaveInstanceState}. This function will never
* be called with a null state.
*
* @param parent the parent CoordinatorLayout
* @param child child view to restore from
* @param state The frozen state that had previously been returned by
* {@link #onSaveInstanceState}.
*
* @see #onSaveInstanceState()
*/
public void onRestoreInstanceState(CoordinatorLayout parent, V child, Parcelable state) {
// no-op
}
/**
* Hook allowing a behavior to generate a representation of its internal state
* that can later be used to create a new instance with that same state.
* This state should only contain information that is not persistent or can
* not be reconstructed later.
*
* <p>Behavior state is only saved when both the parent {@link CoordinatorLayout} and
* a view using this behavior have valid IDs set.</p>
*
* @param parent the parent CoordinatorLayout
* @param child child view to restore from
*
* @return Returns a Parcelable object containing the behavior's current dynamic
* state.
*
* @see #onRestoreInstanceState(android.os.Parcelable)
* @see View#onSaveInstanceState()
*/
public Parcelable onSaveInstanceState(CoordinatorLayout parent, V child) {
return BaseSavedState.EMPTY_STATE;
}
}
/**
* Parameters describing the desired layout for a child of a {@link CoordinatorLayout}.
*/
public static class LayoutParams extends ViewGroup.MarginLayoutParams {
/**
* A {@link Behavior} that the child view should obey.
*/
Behavior mBehavior;
boolean mBehaviorResolved = false;
/**
* A {@link Gravity} value describing how this child view should lay out.
* If an {@link #setAnchorId(int) anchor} is also specified, the gravity describes
* how this child view should be positioned relative to its anchored position.
*/
public int gravity = Gravity.NO_GRAVITY;
/**
* A {@link Gravity} value describing which edge of a child view's
* {@link #getAnchorId() anchor} view the child should position itself relative to.
*/
public int anchorGravity = Gravity.NO_GRAVITY;
/**
* The index of the horizontal keyline specified to the parent CoordinatorLayout that this
* child should align relative to. If an {@link #setAnchorId(int) anchor} is present the
* keyline will be ignored.
*/
public int keyline = -1;
/**
* A {@link View#getId() view id} of a descendant view of the CoordinatorLayout that
* this child should position relative to.
*/
int mAnchorId = View.NO_ID;
View mAnchorView;
View mAnchorDirectChild;
private boolean mDidBlockInteraction;
private boolean mDidAcceptNestedScroll;
private boolean mDidChangeAfterNestedScroll;
final Rect mLastChildRect = new Rect();
Object mBehaviorTag;
public LayoutParams(int width, int height) {
super(width, height);
}
LayoutParams(Context context, AttributeSet attrs) {
super(context, attrs);
final TypedArray a = context.obtainStyledAttributes(attrs,
R.styleable.CoordinatorLayout_LayoutParams);
this.gravity = a.getInteger(
R.styleable.CoordinatorLayout_LayoutParams_android_layout_gravity,
Gravity.NO_GRAVITY);
mAnchorId = a.getResourceId(R.styleable.CoordinatorLayout_LayoutParams_layout_anchor,
View.NO_ID);
this.anchorGravity = a.getInteger(
R.styleable.CoordinatorLayout_LayoutParams_layout_anchorGravity,
Gravity.NO_GRAVITY);
this.keyline = a.getInteger(R.styleable.CoordinatorLayout_LayoutParams_layout_keyline,
-1);
mBehaviorResolved = a.hasValue(
R.styleable.CoordinatorLayout_LayoutParams_layout_behavior);
if (mBehaviorResolved) {
mBehavior = parseBehavior(context, attrs, a.getString(
R.styleable.CoordinatorLayout_LayoutParams_layout_behavior));
}
a.recycle();
}
public LayoutParams(LayoutParams p) {
super(p);
}
public LayoutParams(MarginLayoutParams p) {
super(p);
}
public LayoutParams(ViewGroup.LayoutParams p) {
super(p);
}
/**
* Get the id of this view's anchor.
*
* <p>The view with this id must be a descendant of the CoordinatorLayout containing
* the child view this LayoutParams belongs to. It may not be the child view with
* this LayoutParams or a descendant of it.</p>
*
* @return A {@link View#getId() view id} or {@link View#NO_ID} if there is no anchor
*/
public int getAnchorId() {
return mAnchorId;
}
/**
* Get the id of this view's anchor.
*
* <p>The view with this id must be a descendant of the CoordinatorLayout containing
* the child view this LayoutParams belongs to. It may not be the child view with
* this LayoutParams or a descendant of it.</p>
*
* @param id The {@link View#getId() view id} of the anchor or
* {@link View#NO_ID} if there is no anchor
*/
public void setAnchorId(int id) {
invalidateAnchor();
mAnchorId = id;
}
/**
* Get the behavior governing the layout and interaction of the child view within
* a parent CoordinatorLayout.
*
* @return The current behavior or null if no behavior is specified
*/
public Behavior getBehavior() {
return mBehavior;
}
/**
* Set the behavior governing the layout and interaction of the child view within
* a parent CoordinatorLayout.
*
* <p>Setting a new behavior will remove any currently associated
* {@link Behavior#setTag(android.view.View, Object) Behavior tag}.</p>
*
* @param behavior The behavior to set or null for no special behavior
*/
public void setBehavior(Behavior behavior) {
if (mBehavior != behavior) {
mBehavior = behavior;
mBehaviorTag = null;
mBehaviorResolved = true;
}
}
/**
* Set the last known position rect for this child view
* @param r the rect to set
*/
void setLastChildRect(Rect r) {
mLastChildRect.set(r);
}
/**
* Get the last known position rect for this child view.
* Note: do not mutate the result of this call.
*/
Rect getLastChildRect() {
return mLastChildRect;
}
/**
* Returns true if the anchor id changed to another valid view id since the anchor view
* was resolved.
*/
boolean checkAnchorChanged() {
return mAnchorView == null && mAnchorId != View.NO_ID;
}
/**
* Returns true if the associated Behavior previously blocked interaction with other views
* below the associated child since the touch behavior tracking was last
* {@link #resetTouchBehaviorTracking() reset}.
*
* @see #isBlockingInteractionBelow(CoordinatorLayout, android.view.View)
*/
boolean didBlockInteraction() {
if (mBehavior == null) {
mDidBlockInteraction = false;
}
return mDidBlockInteraction;
}
/**
* Check if the associated Behavior wants to block interaction below the given child
* view. The given child view should be the child this LayoutParams is associated with.
*
* <p>Once interaction is blocked, it will remain blocked until touch interaction tracking
* is {@link #resetTouchBehaviorTracking() reset}.</p>
*
* @param parent the parent CoordinatorLayout
* @param child the child view this LayoutParams is associated with
* @return true to block interaction below the given child
*/
boolean isBlockingInteractionBelow(CoordinatorLayout parent, View child) {
if (mDidBlockInteraction) {
return true;
}
return mDidBlockInteraction |= mBehavior != null
? mBehavior.blocksInteractionBelow(parent, child)
: false;
}
/**
* Reset tracking of Behavior-specific touch interactions. This includes
* interaction blocking.
*
* @see #isBlockingInteractionBelow(CoordinatorLayout, android.view.View)
* @see #didBlockInteraction()
*/
void resetTouchBehaviorTracking() {
mDidBlockInteraction = false;
}
void resetNestedScroll() {
mDidAcceptNestedScroll = false;
}
void acceptNestedScroll(boolean accept) {
mDidAcceptNestedScroll = accept;
}
boolean isNestedScrollAccepted() {
return mDidAcceptNestedScroll;
}
boolean getChangedAfterNestedScroll() {
return mDidChangeAfterNestedScroll;
}
void setChangedAfterNestedScroll(boolean changed) {
mDidChangeAfterNestedScroll = changed;
}
void resetChangedAfterNestedScroll() {
mDidChangeAfterNestedScroll = false;
}
/**
* Check if an associated child view depends on another child view of the CoordinatorLayout.
*
* @param parent the parent CoordinatorLayout
* @param child the child to check
* @param dependency the proposed dependency to check
* @return true if child depends on dependency
*/
boolean dependsOn(CoordinatorLayout parent, View child, View dependency) {
return dependency == mAnchorDirectChild
|| (mBehavior != null && mBehavior.layoutDependsOn(parent, child, dependency));
}
/**
* Invalidate the cached anchor view and direct child ancestor of that anchor.
* The anchor will need to be
* {@link #findAnchorView(CoordinatorLayout, android.view.View) found} before
* being used again.
*/
void invalidateAnchor() {
mAnchorView = mAnchorDirectChild = null;
}
/**
* Locate the appropriate anchor view by the current {@link #setAnchorId(int) anchor id}
* or return the cached anchor view if already known.
*
* @param parent the parent CoordinatorLayout
* @param forChild the child this LayoutParams is associated with
* @return the located descendant anchor view, or null if the anchor id is
* {@link View#NO_ID}.
*/
View findAnchorView(CoordinatorLayout parent, View forChild) {
if (mAnchorId == View.NO_ID) {
mAnchorView = mAnchorDirectChild = null;
return null;
}
if (mAnchorView == null || !verifyAnchorView(forChild, parent)) {
resolveAnchorView(forChild, parent);
}
return mAnchorView;
}
/**
* Check if the child associated with this LayoutParams is currently considered
* "dirty" and needs to be updated. A Behavior should consider a child dirty
* whenever a property returned by another Behavior method would have changed,
* such as dependencies.
*
* @param parent the parent CoordinatorLayout
* @param child the child view associated with this LayoutParams
* @return true if this child view should be considered dirty
*/
boolean isDirty(CoordinatorLayout parent, View child) {
return mBehavior != null && mBehavior.isDirty(parent, child);
}
/**
* Determine the anchor view for the child view this LayoutParams is assigned to.
* Assumes mAnchorId is valid.
*/
private void resolveAnchorView(View forChild, CoordinatorLayout parent) {
mAnchorView = parent.findViewById(mAnchorId);
if (mAnchorView != null) {
View directChild = mAnchorView;
for (ViewParent p = mAnchorView.getParent();
p != parent && p != null;
p = p.getParent()) {
if (p == forChild) {
if (parent.isInEditMode()) {
mAnchorView = mAnchorDirectChild = null;
return;
}
throw new IllegalStateException(
"Anchor must not be a descendant of the anchored view");
}
if (p instanceof View) {
directChild = (View) p;
}
}
mAnchorDirectChild = directChild;
} else {
if (parent.isInEditMode()) {
mAnchorView = mAnchorDirectChild = null;
return;
}
throw new IllegalStateException("Could not find CoordinatorLayout descendant view"
+ " with id " + parent.getResources().getResourceName(mAnchorId)
+ " to anchor view " + forChild);
}
}
/**
* Verify that the previously resolved anchor view is still valid - that it is still
* a descendant of the expected parent view, it is not the child this LayoutParams
* is assigned to or a descendant of it, and it has the expected id.
*/
private boolean verifyAnchorView(View forChild, CoordinatorLayout parent) {
if (mAnchorView.getId() != mAnchorId) {
return false;
}
View directChild = mAnchorView;
for (ViewParent p = mAnchorView.getParent();
p != parent;
p = p.getParent()) {
if (p == null || p == forChild) {
mAnchorView = mAnchorDirectChild = null;
return false;
}
if (p instanceof View) {
directChild = (View) p;
}
}
mAnchorDirectChild = directChild;
return true;
}
}
final class ApplyInsetsListener implements android.support.v4.view.OnApplyWindowInsetsListener {
@Override
public WindowInsetsCompat onApplyWindowInsets(View v, WindowInsetsCompat insets) {
setWindowInsets(insets);
return insets.consumeSystemWindowInsets();
}
}
final class HierarchyChangeListener implements OnHierarchyChangeListener {
@Override
public void onChildViewAdded(View parent, View child) {
if (mOnHierarchyChangeListener != null) {
mOnHierarchyChangeListener.onChildViewAdded(parent, child);
}
}
@Override
public void onChildViewRemoved(View parent, View child) {
dispatchDependentViewRemoved(child);
if (mOnHierarchyChangeListener != null) {
mOnHierarchyChangeListener.onChildViewRemoved(parent, child);
}
}
}
@Override
protected void onRestoreInstanceState(Parcelable state) {
final SavedState ss = (SavedState) state;
super.onRestoreInstanceState(ss.getSuperState());
final SparseArray<Parcelable> behaviorStates = ss.behaviorStates;
for (int i = 0, count = getChildCount(); i < count; i++) {
final View child = getChildAt(i);
final int childId = child.getId();
final LayoutParams lp = getResolvedLayoutParams(child);
final Behavior b = lp.getBehavior();
if (childId != NO_ID && b != null) {
Parcelable savedState = behaviorStates.get(childId);
if (savedState != null) {
b.onRestoreInstanceState(this, child, savedState);
}
}
}
}
@Override
protected Parcelable onSaveInstanceState() {
final SavedState ss = new SavedState(super.onSaveInstanceState());
final SparseArray<Parcelable> behaviorStates = new SparseArray<>();
for (int i = 0, count = getChildCount(); i < count; i++) {
final View child = getChildAt(i);
final int childId = child.getId();
final LayoutParams lp = (LayoutParams) child.getLayoutParams();
final Behavior b = lp.getBehavior();
if (childId != NO_ID && b != null) {
// If the child has an ID and a Behavior, let it save some state...
Parcelable state = b.onSaveInstanceState(this, child);
if (state != null) {
behaviorStates.append(childId, state);
}
}
}
ss.behaviorStates = behaviorStates;
return ss;
}
protected static class SavedState extends BaseSavedState {
SparseArray<Parcelable> behaviorStates;
public SavedState(Parcel source) {
super(source);
final int size = source.readInt();
final int[] ids = new int[size];
source.readIntArray(ids);
final Parcelable[] states = source.readParcelableArray(
CoordinatorLayout.class.getClassLoader());
behaviorStates = new SparseArray<>(size);
for (int i = 0; i < size; i++) {
behaviorStates.append(ids[i], states[i]);
}
}
public SavedState(Parcelable superState) {
super(superState);
}
@Override
public void writeToParcel(Parcel dest, int flags) {
super.writeToParcel(dest, flags);
final int size = behaviorStates != null ? behaviorStates.size() : 0;
dest.writeInt(size);
final int[] ids = new int[size];
final Parcelable[] states = new Parcelable[size];
for (int i = 0; i < size; i++) {
ids[i] = behaviorStates.keyAt(i);
states[i] = behaviorStates.valueAt(i);
}
dest.writeIntArray(ids);
dest.writeParcelableArray(states, flags);
}
public static final Parcelable.Creator<SavedState> CREATOR =
new Parcelable.Creator<SavedState>() {
@Override
public SavedState createFromParcel(Parcel source) {
return new SavedState(source);
}
@Override
public SavedState[] newArray(int size) {
return new SavedState[size];
}
};
}
}