package com.loopeer.codereader.ui.view;
import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.os.Bundle;
import android.os.Parcel;
import android.os.Parcelable;
import android.support.v4.view.AccessibilityDelegateCompat;
import android.support.v4.view.InputDeviceCompat;
import android.support.v4.view.MotionEventCompat;
import android.support.v4.view.NestedScrollingChild;
import android.support.v4.view.NestedScrollingChildHelper;
import android.support.v4.view.NestedScrollingParent;
import android.support.v4.view.NestedScrollingParentHelper;
import android.support.v4.view.VelocityTrackerCompat;
import android.support.v4.view.ViewCompat;
import android.support.v4.view.accessibility.AccessibilityEventCompat;
import android.support.v4.view.accessibility.AccessibilityNodeInfoCompat;
import android.support.v4.view.accessibility.AccessibilityRecordCompat;
import android.support.v4.widget.EdgeEffectCompat;
import android.support.v4.widget.ScrollerCompat;
import android.util.AttributeSet;
import android.util.Log;
import android.util.TypedValue;
import android.view.FocusFinder;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewGroup;
import android.view.ViewParent;
import android.view.accessibility.AccessibilityEvent;
import android.view.animation.AnimationUtils;
import android.widget.FrameLayout;
import android.widget.ScrollView;
import java.util.List;
public class NestHorizontalScrollView extends FrameLayout implements NestedScrollingParent,
NestedScrollingChild {
static final int ANIMATED_SCROLL_GAP = 250;
static final float MAX_SCROLL_FACTOR = 0.5f;
private static final String TAG = "NestedScrollView";
private long mLastScroll;
private final Rect mTempRect = new Rect();
private ScrollerCompat mScroller;
private EdgeEffectCompat mEdgeGlowLeft;
private EdgeEffectCompat mEdgeGlowRight;
/**
* Position of the last motion event.
*/
private int mLastMotionX;
private int mLastMotionY;
/**
* True when the layout has changed but the traversal has not come through yet.
* Ideally the view hierarchy would keep track of this for us.
*/
private boolean mIsLayoutDirty = true;
private boolean mIsLaidOut = false;
/**
* The child to give focus to in the event that a child has requested focus while the
* layout is dirty. This prevents the scroll from being wrong if the child has not been
* laid out before requesting focus.
*/
private View mChildToScrollTo = null;
/**
* True if the user is currently dragging this ScrollView around. This is
* not the same as 'is being flinged', which can be checked by
* mScroller.isFinished() (flinging begins when the user lifts his finger).
*/
private boolean mIsBeingDragged = false;
/**
* Determines speed during touch scrolling
*/
private VelocityTracker mVelocityTracker;
/**
* When set to true, the scroll view measure its child to make it fill the currently
* visible area.
*/
private boolean mFillViewport;
/**
* Whether arrow scrolling is animated.
*/
private boolean mSmoothScrollingEnabled = true;
private int mTouchSlop;
private int mMinimumVelocity;
private int mMaximumVelocity;
/**
* ID of the active pointer. This is used to retain consistency during
* drags/flings if multiple pointers are used.
*/
private int mActivePointerId = INVALID_POINTER;
/**
* Used during scrolling to retrieve the new offset within the window.
*/
private final int[] mScrollOffset = new int[2];
private final int[] mScrollConsumed = new int[2];
private int mNestedXOffset;
/**
* Sentinel value for no current active pointer.
* Used by {@link #mActivePointerId}.
*/
private static final int INVALID_POINTER = -1;
private SavedState mSavedState;
private static final AccessibilityDelegate ACCESSIBILITY_DELEGATE = new AccessibilityDelegate();
private static final int[] SCROLLVIEW_STYLEABLE = new int[] {
android.R.attr.fillViewport
};
private final NestedScrollingParentHelper mParentHelper;
private final NestedScrollingChildHelper mChildHelper;
private float mHorizontalScrollFactor;
public NestHorizontalScrollView(Context context) {
this(context, null);
}
public NestHorizontalScrollView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public NestHorizontalScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
initScrollView();
final TypedArray a = context.obtainStyledAttributes(
attrs, SCROLLVIEW_STYLEABLE, defStyleAttr, 0);
setFillViewport(a.getBoolean(0, false));
a.recycle();
mParentHelper = new NestedScrollingParentHelper(this);
mChildHelper = new NestedScrollingChildHelper(this);
// ...because why else would you be using this widget?
setNestedScrollingEnabled(true);
ViewCompat.setAccessibilityDelegate(this, ACCESSIBILITY_DELEGATE);
}
// NestedScrollingChild
@Override
public void setNestedScrollingEnabled(boolean enabled) {
mChildHelper.setNestedScrollingEnabled(enabled);
}
@Override
public boolean isNestedScrollingEnabled() {
return mChildHelper.isNestedScrollingEnabled();
}
@Override
public boolean startNestedScroll(int axes) {
return mChildHelper.startNestedScroll(axes);
}
@Override
public void stopNestedScroll() {
mChildHelper.stopNestedScroll();
}
@Override
public boolean hasNestedScrollingParent() {
return mChildHelper.hasNestedScrollingParent();
}
@Override
public boolean dispatchNestedScroll(int dxConsumed, int dyConsumed, int dxUnconsumed,
int dyUnconsumed, int[] offsetInWindow) {
return mChildHelper.dispatchNestedScroll(dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed,
offsetInWindow);
}
@Override
public boolean dispatchNestedPreScroll(int dx, int dy, int[] consumed, int[] offsetInWindow) {
return mChildHelper.dispatchNestedPreScroll(dx, dy, consumed, offsetInWindow);
}
@Override
public boolean dispatchNestedFling(float velocityX, float velocityY, boolean consumed) {
return mChildHelper.dispatchNestedFling(velocityX, velocityY, consumed);
}
@Override
public boolean dispatchNestedPreFling(float velocityX, float velocityY) {
return mChildHelper.dispatchNestedPreFling(velocityX, velocityY);
}
// NestedScrollingParent
@Override
public boolean onStartNestedScroll(View child, View target, int nestedScrollAxes) {
return (nestedScrollAxes & ViewCompat.SCROLL_AXIS_HORIZONTAL) != 0;
}
@Override
public void onNestedScrollAccepted(View child, View target, int nestedScrollAxes) {
mParentHelper.onNestedScrollAccepted(child, target, nestedScrollAxes);
startNestedScroll(ViewCompat.SCROLL_AXIS_HORIZONTAL);
}
@Override
public void onStopNestedScroll(View target) {
stopNestedScroll();
}
@Override
public void onNestedScroll(View target, int dxConsumed, int dyConsumed, int dxUnconsumed,
int dyUnconsumed) {
final int oldScrollX = getScrollX();
scrollBy(dxUnconsumed, 0);
final int mxConsumed = getScrollX() - oldScrollX;
final int mxUnconsumed = dxUnconsumed - mxConsumed;
dispatchNestedScroll(mxConsumed, 0, mxUnconsumed, 0, null);
}
@Override
public void onNestedPreScroll(View target, int dx, int dy, int[] consumed) {
// Do nothing
}
@Override
public boolean onNestedFling(View target, float velocityX, float velocityY, boolean consumed) {
if (!consumed) {
flingWithNestedDispatch((int) velocityX);
return true;
}
return false;
}
@Override
public boolean onNestedPreFling(View target, float velocityX, float velocityY) {
// Do nothing
return false;
}
@Override
public int getNestedScrollAxes() {
return mParentHelper.getNestedScrollAxes();
}
// ScrollView import
public boolean shouldDelayChildPressedState() {
return true;
}
@Override
protected float getLeftFadingEdgeStrength() {
if (getChildCount() == 0) {
return 0.0f;
}
final int length = getHorizontalFadingEdgeLength();
final int scrollX = getScrollX();
if (scrollX < length) {
return scrollX / (float) length;
}
return 1.0f;
}
@Override
protected float getRightFadingEdgeStrength() {
if (getChildCount() == 0) {
return 0.0f;
}
final int length = getHorizontalFadingEdgeLength();
final int rightEdge = getWidth() - getPaddingRight();
final int span = getChildAt(0).getRight() - getScrollX() - rightEdge;
if (span < length) {
return span / (float) length;
}
return 1.0f;
}
/**
* @return The maximum amount this scroll view will scroll in response to
* an arrow event.
*/
public int getMaxScrollAmount() {
return (int) (MAX_SCROLL_FACTOR * getWidth());
}
private void initScrollView() {
mScroller = ScrollerCompat.create(getContext(), null);
setFocusable(true);
setDescendantFocusability(FOCUS_AFTER_DESCENDANTS);
setWillNotDraw(false);
final ViewConfiguration configuration = ViewConfiguration.get(getContext());
mTouchSlop = configuration.getScaledTouchSlop();
mMinimumVelocity = configuration.getScaledMinimumFlingVelocity();
mMaximumVelocity = configuration.getScaledMaximumFlingVelocity();
}
@Override
public void addView(View child) {
if (getChildCount() > 0) {
throw new IllegalStateException("ScrollView can host only one direct child");
}
super.addView(child);
}
@Override
public void addView(View child, int index) {
if (getChildCount() > 0) {
throw new IllegalStateException("ScrollView can host only one direct child");
}
super.addView(child, index);
}
@Override
public void addView(View child, ViewGroup.LayoutParams params) {
if (getChildCount() > 0) {
throw new IllegalStateException("ScrollView can host only one direct child");
}
super.addView(child, params);
}
@Override
public void addView(View child, int index, ViewGroup.LayoutParams params) {
if (getChildCount() > 0) {
throw new IllegalStateException("ScrollView can host only one direct child");
}
super.addView(child, index, params);
}
/**
* @return Returns true this ScrollView can be scrolled
*/
private boolean canScroll() {
View child = getChildAt(0);
if (child != null) {
int childWidth = child.getWidth();
return getWidth() < childWidth + getPaddingRight() + getPaddingLeft();
}
return false;
}
/**
* Indicates whether this ScrollView's content is stretched to fill the viewport.
*
* @return True if the content fills the viewport, false otherwise.
*
* @attr ref android.R.styleable#ScrollView_fillViewport
*/
public boolean isFillViewport() {
return mFillViewport;
}
/**
* Indicates this ScrollView whether it should stretch its content height to fill
* the viewport or not.
*
* @param fillViewport True to stretch the content's height to the viewport's
* boundaries, false otherwise.
*
* @attr ref android.R.styleable#ScrollView_fillViewport
*/
public void setFillViewport(boolean fillViewport) {
if (fillViewport != mFillViewport) {
mFillViewport = fillViewport;
requestLayout();
}
}
/**
* @return Whether arrow scrolling will animate its transition.
*/
public boolean isSmoothScrollingEnabled() {
return mSmoothScrollingEnabled;
}
/**
* Set whether arrow scrolling will animate its transition.
* @param smoothScrollingEnabled whether arrow scrolling will animate its transition
*/
public void setSmoothScrollingEnabled(boolean smoothScrollingEnabled) {
mSmoothScrollingEnabled = smoothScrollingEnabled;
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (!mFillViewport) {
return;
}
final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
if (heightMode == MeasureSpec.UNSPECIFIED) {
return;
}
if (getChildCount() > 0) {
final View child = getChildAt(0);
int width = getMeasuredWidth();
if (child.getMeasuredWidth() < width) {
final FrameLayout.LayoutParams lp = (LayoutParams) child.getLayoutParams();
int childHeightMeasureSpec = getChildMeasureSpec(heightMeasureSpec,
getPaddingTop() + getPaddingBottom(), lp.height);
width -= getPaddingRight();
width -= getPaddingLeft();
int childWidthMeasureSpec =
MeasureSpec.makeMeasureSpec(width, MeasureSpec.EXACTLY);
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
}
}
@Override
public boolean dispatchKeyEvent(KeyEvent event) {
// Let the focused view and/or our descendants get the key first
return super.dispatchKeyEvent(event) || executeKeyEvent(event);
}
/**
* You can call this function yourself to have the scroll view perform
* scrolling from a key event, just as if the event had been dispatched to
* it by the view hierarchy.
*
* @param event The key event to execute.
* @return Return true if the event was handled, else false.
*/
public boolean executeKeyEvent(KeyEvent event) {
mTempRect.setEmpty();
if (!canScroll()) {
if (isFocused() && event.getKeyCode() != KeyEvent.KEYCODE_BACK) {
View currentFocused = findFocus();
if (currentFocused == this) currentFocused = null;
View nextFocused = FocusFinder.getInstance().findNextFocus(this,
currentFocused, View.FOCUS_RIGHT);
return nextFocused != null
&& nextFocused != this
&& nextFocused.requestFocus(View.FOCUS_RIGHT);
}
return false;
}
boolean handled = false;
if (event.getAction() == KeyEvent.ACTION_DOWN) {
switch (event.getKeyCode()) {
case KeyEvent.KEYCODE_DPAD_LEFT:
if (!event.isAltPressed()) {
handled = arrowScroll(View.FOCUS_LEFT);
} else {
handled = fullScroll(View.FOCUS_LEFT);
}
break;
case KeyEvent.KEYCODE_DPAD_RIGHT:
if (!event.isAltPressed()) {
handled = arrowScroll(View.FOCUS_RIGHT);
} else {
handled = fullScroll(View.FOCUS_RIGHT);
}
break;
case KeyEvent.KEYCODE_SPACE:
pageScroll(event.isShiftPressed() ? View.FOCUS_LEFT : View.FOCUS_RIGHT);
break;
}
}
return handled;
}
private boolean inChild(int x, int y) {
if (getChildCount() > 0) {
final int scrollX = getScrollX();
final View child = getChildAt(0);
return !(x < child.getLeft() - scrollX
|| x >= child.getRight() - scrollX
|| y < child.getTop()
|| y >= child.getBottom());
}
return false;
}
private void initOrResetVelocityTracker() {
if (mVelocityTracker == null) {
mVelocityTracker = VelocityTracker.obtain();
} else {
mVelocityTracker.clear();
}
}
private void initVelocityTrackerIfNotExists() {
if (mVelocityTracker == null) {
mVelocityTracker = VelocityTracker.obtain();
}
}
private void recycleVelocityTracker() {
if (mVelocityTracker != null) {
mVelocityTracker.recycle();
mVelocityTracker = null;
}
}
@Override
public void requestDisallowInterceptTouchEvent(boolean disallowIntercept) {
if (disallowIntercept) {
recycleVelocityTracker();
}
super.requestDisallowInterceptTouchEvent(disallowIntercept);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
/*
* This method JUST determines whether we want to intercept the motion.
* If we return true, onMotionEvent will be called and we do the actual
* scrolling there.
*/
/*
* Shortcut the most recurring case: the user is in the dragging
* state and he is moving his finger. We want to intercept this
* motion.
*/
final int action = ev.getAction();
if ((action == MotionEvent.ACTION_MOVE) && (mIsBeingDragged)) {
return true;
}
switch (action & MotionEventCompat.ACTION_MASK) {
case MotionEvent.ACTION_MOVE: {
/*
* mIsBeingDragged == false, otherwise the shortcut would have caught it. Check
* whether the user has moved far enough from his original down touch.
*/
/*
* Locally do absolute value. mLastMotionY is set to the y value
* of the down event.
*/
final int activePointerId = mActivePointerId;
if (activePointerId == INVALID_POINTER) {
// If we don't have a valid id, the touch down wasn't on content.
break;
}
final int pointerIndex = MotionEventCompat.findPointerIndex(ev, activePointerId);
if (pointerIndex == -1) {
Log.e(TAG, "Invalid pointerId=" + activePointerId
+ " in onInterceptTouchEvent");
break;
}
final int x = (int) MotionEventCompat.getX(ev, pointerIndex);
final int y = (int) MotionEventCompat.getY(ev, pointerIndex);
final int xDiff = Math.abs(x - mLastMotionX);
final int yDiff = Math.abs(y - mLastMotionY);
if (xDiff > mTouchSlop && xDiff > yDiff
&& (getNestedScrollAxes() & ViewCompat.SCROLL_AXIS_HORIZONTAL) == 0) {
mIsBeingDragged = true;
mLastMotionX = x;
mLastMotionY = y;
initVelocityTrackerIfNotExists();
mVelocityTracker.addMovement(ev);
mNestedXOffset = 0;
final ViewParent parent = getParent();
if (parent != null) {
parent.requestDisallowInterceptTouchEvent(true);
}
} else {
mIsBeingDragged = false;
}
break;
}
case MotionEvent.ACTION_DOWN: {
final int x = (int) ev.getX();
final int y = (int) ev.getY();
if (!inChild(x, y)) {
mIsBeingDragged = false;
recycleVelocityTracker();
break;
}
/*
* Remember location of down touch.
* ACTION_DOWN always refers to pointer index 0.
*/
mLastMotionX = x;
mLastMotionY = y;
mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
initOrResetVelocityTracker();
mVelocityTracker.addMovement(ev);
/*
* If being flinged and user touches the screen, initiate drag;
* otherwise don't. mScroller.isFinished should be false when
* being flinged.
*/
mIsBeingDragged = !mScroller.isFinished();
startNestedScroll(ViewCompat.SCROLL_AXIS_HORIZONTAL);
break;
}
case MotionEvent.ACTION_CANCEL:
case MotionEvent.ACTION_UP:
/* Release the drag */
mIsBeingDragged = false;
mActivePointerId = INVALID_POINTER;
recycleVelocityTracker();
stopNestedScroll();
break;
case MotionEventCompat.ACTION_POINTER_UP:
onSecondaryPointerUp(ev);
break;
}
/*
* The only time we want to intercept motion events is if we are in the
* drag mode.
*/
return mIsBeingDragged;
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
initVelocityTrackerIfNotExists();
MotionEvent vtev = MotionEvent.obtain(ev);
final int actionMasked = MotionEventCompat.getActionMasked(ev);
if (actionMasked == MotionEvent.ACTION_DOWN) {
mNestedXOffset = 0;
}
vtev.offsetLocation(mNestedXOffset, 0);
switch (actionMasked) {
case MotionEvent.ACTION_DOWN: {
if (getChildCount() == 0) {
return false;
}
if ((mIsBeingDragged = !mScroller.isFinished())) {
final ViewParent parent = getParent();
if (parent != null) {
parent.requestDisallowInterceptTouchEvent(true);
}
}
/*
* If being flinged and user touches, stop the fling. isFinished
* will be false if being flinged.
*/
if (!mScroller.isFinished()) {
mScroller.abortAnimation();
}
// Remember where the motion event started
mLastMotionX = (int) ev.getX();
mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
startNestedScroll(ViewCompat.SCROLL_AXIS_HORIZONTAL);
break;
}
case MotionEvent.ACTION_MOVE:
final int activePointerIndex = MotionEventCompat.findPointerIndex(ev,
mActivePointerId);
if (activePointerIndex == -1) {
Log.e(TAG, "Invalid pointerId=" + mActivePointerId + " in onTouchEvent");
break;
}
final int x = (int) MotionEventCompat.getX(ev, activePointerIndex);
int deltaX = mLastMotionX - x;
if (dispatchNestedPreScroll(deltaX, 0, mScrollConsumed, mScrollOffset)) {
deltaX -= mScrollConsumed[0];
vtev.offsetLocation(mScrollOffset[0], 0);
mNestedXOffset += mScrollOffset[0];
}
if (!mIsBeingDragged && Math.abs(deltaX) > mTouchSlop) {
final ViewParent parent = getParent();
if (parent != null) {
parent.requestDisallowInterceptTouchEvent(true);
}
mIsBeingDragged = true;
if (deltaX > 0) {
deltaX -= mTouchSlop;
} else {
deltaX += mTouchSlop;
}
}
if (mIsBeingDragged) {
// Scroll to follow the motion event
mLastMotionX = x - mScrollOffset[0];
final int oldX = getScrollX();
final int range = getScrollRange();
final int overscrollMode = ViewCompat.getOverScrollMode(this);
boolean canOverscroll = overscrollMode == ViewCompat.OVER_SCROLL_ALWAYS ||
(overscrollMode == ViewCompat.OVER_SCROLL_IF_CONTENT_SCROLLS &&
range > 0);
// Calling overScrollByCompat will call onOverScrolled, which
// calls onScrollChanged if applicable.
if (overScrollByCompat(deltaX, 0, getScrollX(), 0, range, 0, 0,
0, true) && !hasNestedScrollingParent()) {
// Break our velocity if we hit a scroll barrier.
mVelocityTracker.clear();
}
final int scrolledDeltaX = getScrollX() - oldX;
final int unconsumedX = deltaX - scrolledDeltaX;
if (dispatchNestedScroll(scrolledDeltaX, 0, unconsumedX, 0, mScrollOffset)) {
mLastMotionX -= mScrollOffset[0];
vtev.offsetLocation(mScrollOffset[0], 0);
mNestedXOffset += mScrollOffset[0];
} else if (canOverscroll) {
ensureGlows();
final int pulledToX = oldX + deltaX;
if (pulledToX < 0) {
mEdgeGlowLeft.onPull((float) deltaX / getWidth(),
MotionEventCompat.getY(ev, activePointerIndex) / getHeight());
if (!mEdgeGlowRight.isFinished()) {
mEdgeGlowRight.onRelease();
}
} else if (pulledToX > range) {
mEdgeGlowRight.onPull((float) deltaX / getWidth(),
1.f - MotionEventCompat.getY(ev, activePointerIndex)
/ getHeight());
if (!mEdgeGlowLeft.isFinished()) {
mEdgeGlowLeft.onRelease();
}
}
if (mEdgeGlowLeft != null
&& (!mEdgeGlowLeft.isFinished() || !mEdgeGlowRight.isFinished())) {
ViewCompat.postInvalidateOnAnimation(this);
}
}
}
break;
case MotionEvent.ACTION_UP:
if (mIsBeingDragged) {
final VelocityTracker velocityTracker = mVelocityTracker;
velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
int initialVelocity = (int) VelocityTrackerCompat.getXVelocity(velocityTracker,
mActivePointerId);
if ((Math.abs(initialVelocity) > mMinimumVelocity)) {
flingWithNestedDispatch(-initialVelocity);
}
mActivePointerId = INVALID_POINTER;
endDrag();
}
break;
case MotionEvent.ACTION_CANCEL:
if (mIsBeingDragged && getChildCount() > 0) {
mActivePointerId = INVALID_POINTER;
endDrag();
}
break;
case MotionEventCompat.ACTION_POINTER_DOWN: {
final int index = MotionEventCompat.getActionIndex(ev);
mLastMotionX = (int) MotionEventCompat.getX(ev, index);
mActivePointerId = MotionEventCompat.getPointerId(ev, index);
break;
}
case MotionEventCompat.ACTION_POINTER_UP:
onSecondaryPointerUp(ev);
mLastMotionX = (int) MotionEventCompat.getX(ev,
MotionEventCompat.findPointerIndex(ev, mActivePointerId));
break;
}
if (mVelocityTracker != null) {
mVelocityTracker.addMovement(vtev);
}
vtev.recycle();
return true;
}
private void onSecondaryPointerUp(MotionEvent ev) {
final int pointerIndex = (ev.getAction() & MotionEventCompat.ACTION_POINTER_INDEX_MASK) >>
MotionEventCompat.ACTION_POINTER_INDEX_SHIFT;
final int pointerId = MotionEventCompat.getPointerId(ev, pointerIndex);
if (pointerId == mActivePointerId) {
// This was our active pointer going up. Choose a new
// active pointer and adjust accordingly.
// TODO: Make this decision more intelligent.
final int newPointerIndex = pointerIndex == 0 ? 1 : 0;
mLastMotionX = (int) MotionEventCompat.getX(ev, newPointerIndex);
mActivePointerId = MotionEventCompat.getPointerId(ev, newPointerIndex);
if (mVelocityTracker != null) {
mVelocityTracker.clear();
}
}
}
public boolean onGenericMotionEvent(MotionEvent event) {
if ((MotionEventCompat.getSource(event) & InputDeviceCompat.SOURCE_CLASS_POINTER) != 0) {
switch (event.getAction()) {
case MotionEventCompat.ACTION_SCROLL: {
if (!mIsBeingDragged) {
final float hscroll = MotionEventCompat.getAxisValue(event,
MotionEventCompat.AXIS_HSCROLL);
if (hscroll != 0) {
final int delta = (int) (hscroll * getHorizontalScrollFactorCompat());
final int range = getScrollRange();
int oldScrollX = getScrollX();
int newScrollX = oldScrollX - delta;
if (newScrollX < 0) {
newScrollX = 0;
} else if (newScrollX > range) {
newScrollX = range;
}
if (newScrollX != oldScrollX) {
super.scrollTo(newScrollX, getScrollY());
return true;
}
}
}
}
}
}
return false;
}
private float getHorizontalScrollFactorCompat() {
if (mHorizontalScrollFactor == 0) {
TypedValue outValue = new TypedValue();
final Context context = getContext();
if (!context.getTheme().resolveAttribute(
android.R.attr.listPreferredItemHeight, outValue, true)) {
throw new IllegalStateException(
"Expected theme to define listPreferredItemHeight.");
}
mHorizontalScrollFactor = outValue.getDimension(
context.getResources().getDisplayMetrics());
}
return mHorizontalScrollFactor;
}
protected void onOverScrolled(int scrollX, int scrollY,
boolean clampedX, boolean clampedY) {
super.scrollTo(scrollX, scrollY);
}
boolean overScrollByCompat(int deltaX, int deltaY,
int scrollX, int scrollY,
int scrollRangeX, int scrollRangeY,
int maxOverScrollX, int maxOverScrollY,
boolean isTouchEvent) {
final int overScrollMode = ViewCompat.getOverScrollMode(this);
final boolean canScrollHorizontal =
computeHorizontalScrollRange() > computeHorizontalScrollExtent();
final boolean canScrollVertical =
computeVerticalScrollRange() > computeVerticalScrollExtent();
final boolean overScrollHorizontal = overScrollMode == ViewCompat.OVER_SCROLL_ALWAYS ||
(overScrollMode == ViewCompat.OVER_SCROLL_IF_CONTENT_SCROLLS && canScrollHorizontal);
final boolean overScrollVertical = overScrollMode == ViewCompat.OVER_SCROLL_ALWAYS ||
(overScrollMode == ViewCompat.OVER_SCROLL_IF_CONTENT_SCROLLS && canScrollVertical);
int newScrollX = scrollX + deltaX;
if (!overScrollHorizontal) {
maxOverScrollX = 0;
}
int newScrollY = scrollY + deltaY;
if (!overScrollVertical) {
maxOverScrollY = 0;
}
// Clamp values if at the limits and record
final int left = -maxOverScrollX;
final int right = maxOverScrollX + scrollRangeX;
final int top = -maxOverScrollY;
final int bottom = maxOverScrollY + scrollRangeY;
boolean clampedX = false;
if (newScrollX > right) {
newScrollX = right;
clampedX = true;
} else if (newScrollX < left) {
newScrollX = left;
clampedX = true;
}
boolean clampedY = false;
if (newScrollY > bottom) {
newScrollY = bottom;
clampedY = true;
} else if (newScrollY < top) {
newScrollY = top;
clampedY = true;
}
onOverScrolled(newScrollX, newScrollY, clampedX, clampedY);
return clampedX || clampedY;
}
private int getScrollRange() {
int scrollRange = 0;
if (getChildCount() > 0) {
View child = getChildAt(0);
scrollRange = Math.max(0,
child.getWidth() - (getWidth() - getPaddingLeft() - getPaddingRight()));
}
return scrollRange;
}
/**
* <p>
* Finds the next focusable component that fits in the specified bounds.
* </p>
*
* @param topFocus look for a candidate is the one at the top of the bounds
* if topFocus is true, or at the bottom of the bounds if topFocus is
* false
* @param left the left offset of the bounds in which a focusable must be
* found
* @param right the right offset of the bounds in which a focusable must
* be found
* @return the next focusable component in the bounds or null if none can
* be found
*/
private View findFocusableViewInBounds(boolean topFocus, int left, int right) {
List<View> focusables = getFocusables(View.FOCUS_FORWARD);
View focusCandidate = null;
/*
* A fully contained focusable is one where its top is below the bound's
* top, and its bottom is above the bound's bottom. A partially
* contained focusable is one where some part of it is within the
* bounds, but it also has some part that is not within bounds. A fully contained
* focusable is preferred to a partially contained focusable.
*/
boolean foundFullyContainedFocusable = false;
int count = focusables.size();
for (int i = 0; i < count; i++) {
View view = focusables.get(i);
int viewLeft = view.getLeft();
int viewRight = view.getRight();
if (left < viewRight && viewLeft < right) {
/*
* the focusable is in the target area, it is a candidate for
* focusing
*/
final boolean viewIsFullyContained = (left < viewLeft) &&
(viewRight < right);
if (focusCandidate == null) {
/* No candidate, take this one */
focusCandidate = view;
foundFullyContainedFocusable = viewIsFullyContained;
} else {
final boolean viewIsCloserToBoundary =
(topFocus && viewLeft < focusCandidate.getLeft()) ||
(!topFocus && viewRight > focusCandidate
.getRight());
if (foundFullyContainedFocusable) {
if (viewIsFullyContained && viewIsCloserToBoundary) {
/*
* We're dealing with only fully contained views, so
* it has to be closer to the boundary to beat our
* candidate
*/
focusCandidate = view;
}
} else {
if (viewIsFullyContained) {
/* Any fully contained view beats a partially contained view */
focusCandidate = view;
foundFullyContainedFocusable = true;
} else if (viewIsCloserToBoundary) {
/*
* Partially contained view beats another partially
* contained view if it's closer
*/
focusCandidate = view;
}
}
}
}
}
return focusCandidate;
}
/**
* <p>Handles scrolling in response to a "page up/down" shortcut press. This
* method will scroll the view by one page up or down and give the focus
* to the topmost/bottommost component in the new visible area. If no
* component is a good candidate for focus, this scrollview reclaims the
* focus.</p>
*
* @param direction the scroll direction: {@link android.view.View#FOCUS_UP}
* to go one page up or
* {@link android.view.View#FOCUS_RIGHT} to go one page down
* @return true if the key event is consumed by this method, false otherwise
*/
public boolean pageScroll(int direction) {
boolean toRight = direction == View.FOCUS_RIGHT;
int width = getWidth();
if (toRight) {
mTempRect.left = getScrollX() + width;
int count = getChildCount();
if (count > 0) {
View view = getChildAt(count - 1);
if (mTempRect.left + width > view.getRight()) {
mTempRect.left = view.getRight() - width;
}
}
} else {
mTempRect.left = getScrollX() - width;
if (mTempRect.left < 0) {
mTempRect.left = 0;
}
}
mTempRect.right = mTempRect.left + width;
return scrollAndFocus(direction, mTempRect.left, mTempRect.right);
}
/**
* <p>Handles scrolling in response to a "home/end" shortcut press. This
* method will scroll the view to the top or bottom and give the focus
* to the topmost/bottommost component in the new visible area. If no
* component is a good candidate for focus, this scrollview reclaims the
* focus.</p>
*
* @param direction the scroll direction: {@link android.view.View#FOCUS_UP}
* to go the top of the view or
* {@link android.view.View#FOCUS_DOWN} to go the bottom
* @return true if the key event is consumed by this method, false otherwise
*/
public boolean fullScroll(int direction) {
boolean right = direction == View.FOCUS_RIGHT;
int width = getWidth();
mTempRect.left = 0;
mTempRect.right = width;
if (right) {
int count = getChildCount();
if (count > 0) {
View view = getChildAt(count - 1);
mTempRect.right = view.getRight() + getPaddingRight();
mTempRect.left = mTempRect.right - width;
}
}
return scrollAndFocus(direction, mTempRect.left, mTempRect.right);
}
/**
* <p>Scrolls the view to make the area defined by <code>top</code> and
* <code>bottom</code> visible. This method attempts to give the focus
* to a component visible in this area. If no component can be focused in
* the new visible area, the focus is reclaimed by this ScrollView.</p>
*
* @param direction the scroll direction: {@link android.view.View#FOCUS_UP}
* to go upward, {@link android.view.View#FOCUS_DOWN} to downward
* @param left the left offset of the new area to be made visible
* @param right the right offset of the new area to be made visible
* @return true if the key event is consumed by this method, false otherwise
*/
private boolean scrollAndFocus(int direction, int left, int right) {
boolean handled = true;
int width = getWidth();
int containerLeft = getScrollX();
int containerRight = containerLeft + width;
boolean toLeft = direction == View.FOCUS_LEFT;
View newFocused = findFocusableViewInBounds(toLeft, left, right);
if (newFocused == null) {
newFocused = this;
}
if (left >= containerLeft && right <= containerRight) {
handled = false;
} else {
int delta = toLeft ? (left - containerLeft) : (right - containerRight);
doScrollX(delta);
}
if (newFocused != findFocus()) newFocused.requestFocus(direction);
return handled;
}
/**
* Handle scrolling in response to an up or down arrow click.
*
* @param direction The direction corresponding to the arrow key that was
* pressed
* @return True if we consumed the event, false otherwise
*/
public boolean arrowScroll(int direction) {
View currentFocused = findFocus();
if (currentFocused == this) currentFocused = null;
View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused, direction);
final int maxJump = getMaxScrollAmount();
if (nextFocused != null && isWithinDeltaOfScreen(nextFocused, maxJump, getHeight())) {
nextFocused.getDrawingRect(mTempRect);
offsetDescendantRectToMyCoords(nextFocused, mTempRect);
int scrollDelta = computeScrollDeltaToGetChildRectOnScreen(mTempRect);
doScrollX(scrollDelta);
nextFocused.requestFocus(direction);
} else {
// no new focus
int scrollDelta = maxJump;
if (direction == View.FOCUS_LEFT && getScrollX() < scrollDelta) {
scrollDelta = getScrollX();
} else if (direction == View.FOCUS_RIGHT) {
if (getChildCount() > 0) {
int daRight = getChildAt(0).getRight();
int screenRight = getScrollX() + getWidth() - getPaddingRight();
if (daRight - screenRight < maxJump) {
scrollDelta = daRight - screenRight;
}
}
}
if (scrollDelta == 0) {
return false;
}
doScrollX(direction == View.FOCUS_RIGHT ? scrollDelta : -scrollDelta);
}
if (currentFocused != null && currentFocused.isFocused()
&& isOffScreen(currentFocused)) {
// previously focused item still has focus and is off screen, give
// it up (take it back to ourselves)
// (also, need to temporarily force FOCUS_BEFORE_DESCENDANTS so we are
// sure to
// get it)
final int descendantFocusability = getDescendantFocusability(); // save
setDescendantFocusability(ViewGroup.FOCUS_BEFORE_DESCENDANTS);
requestFocus();
setDescendantFocusability(descendantFocusability); // restore
}
return true;
}
/**
* @return whether the descendant of this scroll view is scrolled off
* screen.
*/
private boolean isOffScreen(View descendant) {
return !isWithinDeltaOfScreen(descendant, 0, getWidth());
}
/**
* @return whether the descendant of this scroll view is within delta
* pixels of being on the screen.
*/
private boolean isWithinDeltaOfScreen(View descendant, int delta, int width) {
descendant.getDrawingRect(mTempRect);
offsetDescendantRectToMyCoords(descendant, mTempRect);
return (mTempRect.right + delta) >= getScrollX()
&& (mTempRect.left - delta) <= (getScrollX() + width);
}
/**
* Smooth scroll by a X delta
*
* @param delta the number of pixels to scroll by on the X axis
*/
private void doScrollX(int delta) {
if (delta != 0) {
if (mSmoothScrollingEnabled) {
smoothScrollBy(delta, 0);
} else {
scrollBy(delta, 0);
}
}
}
/**
* Like {@link View#scrollBy}, but scroll smoothly instead of immediately.
*
* @param dx the number of pixels to scroll by on the X axis
* @param dy the number of pixels to scroll by on the Y axis
*/
public final void smoothScrollBy(int dx, int dy) {
if (getChildCount() == 0) {
// Nothing to do.
return;
}
long duration = AnimationUtils.currentAnimationTimeMillis() - mLastScroll;
if (duration > ANIMATED_SCROLL_GAP) {
final int width = getWidth() - getPaddingLeft() - getPaddingRight();
final int right = getChildAt(0).getWidth();
final int maxX = Math.max(0, right - width);
final int scrollX = getScrollX();
dx = Math.max(0, Math.min(scrollX + dx, maxX)) - scrollX;
mScroller.startScroll(scrollX, getScrollY(), dx, 0);
ViewCompat.postInvalidateOnAnimation(this);
} else {
if (!mScroller.isFinished()) {
mScroller.abortAnimation();
}
scrollBy(dx, dy);
}
mLastScroll = AnimationUtils.currentAnimationTimeMillis();
}
/**
* Like {@link #scrollTo}, but scroll smoothly instead of immediately.
*
* @param x the position where to scroll on the X axis
* @param y the position where to scroll on the Y axis
*/
public final void smoothScrollTo(int x, int y) {
smoothScrollBy(x - getScrollX(), y - getScrollY());
}
@Override
protected int computeHorizontalScrollRange() {
final int count = getChildCount();
final int contentWidth = getWidth() - getPaddingLeft() - getPaddingRight();
if (count == 0) {
return contentWidth;
}
int scrollRange = getChildAt(0).getRight();
final int scrollX = getScrollX();
final int overscrollRight = Math.max(0, scrollRange - contentWidth);
if (scrollX < 0) {
scrollRange -= scrollX;
} else if (scrollX > overscrollRight) {
scrollRange += scrollX - overscrollRight;
}
return scrollRange;
}
@Override
protected int computeHorizontalScrollOffset() {
return Math.max(0, super.computeHorizontalScrollOffset());
}
@Override
protected void measureChild(View child, int parentWidthMeasureSpec, int parentHeightMeasureSpec) {
ViewGroup.LayoutParams lp = child.getLayoutParams();
int childWidthMeasureSpec;
int childHeightMeasureSpec;
childHeightMeasureSpec = getChildMeasureSpec(parentHeightMeasureSpec, getPaddingTop()
+ getPaddingBottom(), lp.height);
childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
@Override
protected void measureChildWithMargins(View child, int parentWidthMeasureSpec, int widthUsed,
int parentHeightMeasureSpec, int heightUsed) {
final MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();
final int childHeightMeasureSpec = getChildMeasureSpec(parentHeightMeasureSpec,
getPaddingTop() + getPaddingBottom() + lp.topMargin + lp.bottomMargin
+ heightUsed, lp.height);
final int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(
lp.leftMargin + lp.rightMargin, MeasureSpec.UNSPECIFIED);
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
@Override
public void computeScroll() {
if (mScroller.computeScrollOffset()) {
int oldX = getScrollX();
int oldY = getScrollY();
int x = mScroller.getCurrX();
int y = mScroller.getCurrY();
if (oldX != x || oldY != y) {
final int range = getScrollRange();
final int overscrollMode = ViewCompat.getOverScrollMode(this);
final boolean canOverscroll = overscrollMode == ViewCompat.OVER_SCROLL_ALWAYS ||
(overscrollMode == ViewCompat.OVER_SCROLL_IF_CONTENT_SCROLLS && range > 0);
overScrollByCompat(x - oldX, y - oldY, oldX, oldY, range, 0,
0, 0, false);
if (canOverscroll) {
ensureGlows();
if (x <= 0 && oldX > 0) {
mEdgeGlowLeft.onAbsorb((int) mScroller.getCurrVelocity());
} else if (x >= range && oldX < range) {
mEdgeGlowRight.onAbsorb((int) mScroller.getCurrVelocity());
}
}
}
}
}
/**
* Scrolls the view to the given child.
*
* @param child the View to scroll to
*/
private void scrollToChild(View child) {
child.getDrawingRect(mTempRect);
/* Offset from child's local coordinates to ScrollView coordinates */
offsetDescendantRectToMyCoords(child, mTempRect);
int scrollDelta = computeScrollDeltaToGetChildRectOnScreen(mTempRect);
if (scrollDelta != 0) {
scrollBy(scrollDelta, 0);
}
}
/**
* If rect is off screen, scroll just enough to get it (or at least the
* first screen size chunk of it) on screen.
*
* @param rect The rectangle.
* @param immediate True to scroll immediately without animation
* @return true if scrolling was performed
*/
private boolean scrollToChildRect(Rect rect, boolean immediate) {
final int delta = computeScrollDeltaToGetChildRectOnScreen(rect);
final boolean scroll = delta != 0;
if (scroll) {
if (immediate) {
scrollBy(delta, 0);
} else {
smoothScrollBy(delta, 0);
}
}
return scroll;
}
/**
* Compute the amount to scroll in the Y direction in order to get
* a rectangle completely on the screen (or, if taller than the screen,
* at least the first screen size chunk of it).
*
* @param rect The rect.
* @return The scroll delta.
*/
protected int computeScrollDeltaToGetChildRectOnScreen(Rect rect) {
if (getChildCount() == 0) return 0;
int width = getWidth();
int screenLeft = getScrollX();
int screenRight = screenLeft + width;
int fadingEdge = getHorizontalFadingEdgeLength();
// leave room for top fading edge as long as rect isn't at very top
if (rect.left > 0) {
screenLeft += fadingEdge;
}
// leave room for bottom fading edge as long as rect isn't at very bottom
if (rect.right < getChildAt(0).getWidth()) {
screenRight -= fadingEdge;
}
int scrollXDelta = 0;
if (rect.right > screenRight && rect.left > screenLeft) {
// need to move down to get it in view: move down just enough so
// that the entire rectangle is in view (or at least the first
// screen size chunk).
if (rect.width() > width) {
// just enough to get screen size chunk on
scrollXDelta += (rect.left - screenLeft);
} else {
// get entire rect at bottom of screen
scrollXDelta += (rect.right - screenRight);
}
// make sure we aren't scrolling beyond the end of our content
int right = getChildAt(0).getRight();
int distanceToRight = right - screenRight;
scrollXDelta = Math.min(scrollXDelta, distanceToRight);
} else if (rect.left < screenLeft && rect.right < screenRight) {
// need to move up to get it in view: move up just enough so that
// entire rectangle is in view (or at least the first screen
// size chunk of it).
if (rect.width() > width) {
// screen size chunk
scrollXDelta -= (screenRight - rect.right);
} else {
// entire rect at top
scrollXDelta -= (screenLeft - rect.left);
}
// make sure we aren't scrolling any further than the top our content
scrollXDelta = Math.max(scrollXDelta, -getScrollX());
}
return scrollXDelta;
}
@Override
public void requestChildFocus(View child, View focused) {
if (!mIsLayoutDirty) {
scrollToChild(focused);
} else {
// The child may not be laid out yet, we can't compute the scroll yet
mChildToScrollTo = focused;
}
super.requestChildFocus(child, focused);
}
/**
* When looking for focus in children of a scroll view, need to be a little
* more careful not to give focus to something that is scrolled off screen.
*
* This is more expensive than the default {@link android.view.ViewGroup}
* implementation, otherwise this behavior might have been made the default.
*/
@Override
protected boolean onRequestFocusInDescendants(int direction,
Rect previouslyFocusedRect) {
// convert from forward / backward notation to up / down / left / right
// (ugh).
if (direction == View.FOCUS_FORWARD) {
direction = View.FOCUS_RIGHT;
} else if (direction == View.FOCUS_BACKWARD) {
direction = View.FOCUS_LEFT;
}
final View nextFocus = previouslyFocusedRect == null ?
FocusFinder.getInstance().findNextFocus(this, null, direction) :
FocusFinder.getInstance().findNextFocusFromRect(this,
previouslyFocusedRect, direction);
if (nextFocus == null) {
return false;
}
if (isOffScreen(nextFocus)) {
return false;
}
return nextFocus.requestFocus(direction, previouslyFocusedRect);
}
@Override
public boolean requestChildRectangleOnScreen(View child, Rect rectangle,
boolean immediate) {
// offset into coordinate space of this scroll view
rectangle.offset(child.getLeft() - child.getScrollX(),
child.getTop() - child.getScrollY());
return scrollToChildRect(rectangle, immediate);
}
@Override
public void requestLayout() {
mIsLayoutDirty = true;
super.requestLayout();
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
super.onLayout(changed, l, t, r, b);
mIsLayoutDirty = false;
// Give a child focus if it needs it
if (mChildToScrollTo != null && isViewDescendantOf(mChildToScrollTo, this)) {
scrollToChild(mChildToScrollTo);
}
mChildToScrollTo = null;
if (!mIsLaidOut) {
if (mSavedState != null) {
scrollTo(mSavedState.scrollPosition, getScrollY());
mSavedState = null;
} // mScrollY default value is "0"
final int childWidth = (getChildCount() > 0) ? getChildAt(0).getMeasuredWidth() : 0;
final int scrollRange = Math.max(0,
childWidth - (r - l - getPaddingRight() - getPaddingLeft()));
// Don't forget to clamp
if (getScrollX() > scrollRange) {
scrollTo(scrollRange, getScrollY());
} else if (getScrollX() < 0) {
scrollTo(0, getScrollY());
}
}
// Calling this with the present values causes it to re-claim them
scrollTo(getScrollX(), getScrollY());
mIsLaidOut = true;
}
@SuppressLint("MissingSuperCall")
@Override
public void onAttachedToWindow() {
mIsLaidOut = false;
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
View currentFocused = findFocus();
if (null == currentFocused || this == currentFocused)
return;
// If the currently-focused view was visible on the screen when the
// screen was at the old height, then scroll the screen to make that
// view visible with the new screen height.
if (isWithinDeltaOfScreen(currentFocused, 0, oldw)) {
currentFocused.getDrawingRect(mTempRect);
offsetDescendantRectToMyCoords(currentFocused, mTempRect);
int scrollDelta = computeScrollDeltaToGetChildRectOnScreen(mTempRect);
doScrollX(scrollDelta);
}
}
/**
* Return true if child is a descendant of parent, (or equal to the parent).
*/
private static boolean isViewDescendantOf(View child, View parent) {
if (child == parent) {
return true;
}
final ViewParent theParent = child.getParent();
return (theParent instanceof ViewGroup) && isViewDescendantOf((View) theParent, parent);
}
/**
* Fling the scroll view
*
* @param velocityX The initial velocity in the X direction. Positive
* numbers mean that the finger/cursor is moving down the screen,
* which means we want to scroll towards the top.
*/
public void fling(int velocityX) {
if (getChildCount() > 0) {
int width = getWidth() - getPaddingRight() - getPaddingLeft();
int right = getChildAt(0).getWidth();
mScroller.fling(getScrollX(), getScrollY(), velocityX, 0, 0, Math.max(0, right - width)
, 0,
0, width/2, 0);
ViewCompat.postInvalidateOnAnimation(this);
}
}
private void flingWithNestedDispatch(int velocityX) {
final int scrollX = getScrollX();
final boolean canFling = (scrollX > 0 || velocityX > 0) &&
(scrollX < getScrollRange() || velocityX < 0);
if (!dispatchNestedPreFling(velocityX, 0)) {
dispatchNestedFling(velocityX, 0, canFling);
if (canFling) {
fling(velocityX);
}
}
}
private void endDrag() {
mIsBeingDragged = false;
recycleVelocityTracker();
stopNestedScroll();
if (mEdgeGlowLeft != null) {
mEdgeGlowLeft.onRelease();
mEdgeGlowRight.onRelease();
}
}
/**
* {@inheritDoc}
*
* <p>This version also clamps the scrolling to the bounds of our child.
*/
@Override
public void scrollTo(int x, int y) {
// we rely on the fact the View.scrollBy calls scrollTo.
if (getChildCount() > 0) {
View child = getChildAt(0);
x = clamp(x, getWidth() - getPaddingRight() - getPaddingLeft(), child.getWidth());
y = clamp(y, getHeight() - getPaddingBottom() - getPaddingTop(), child.getHeight());
if (x != getScrollX() || y != getScrollY()) {
super.scrollTo(x, y);
}
}
}
private void ensureGlows() {
if (ViewCompat.getOverScrollMode(this) != ViewCompat.OVER_SCROLL_NEVER) {
if (mEdgeGlowLeft == null) {
Context context = getContext();
mEdgeGlowLeft = new EdgeEffectCompat(context);
mEdgeGlowRight = new EdgeEffectCompat(context);
}
} else {
mEdgeGlowLeft = null;
mEdgeGlowRight = null;
}
}
@Override
public void draw(Canvas canvas) {
super.draw(canvas);
if (mEdgeGlowLeft != null) {
final int scrollX = getScrollX();
if (!mEdgeGlowLeft.isFinished()) {
final int restoreCount = canvas.save();
final int height = getHeight() - getPaddingTop() - getPaddingBottom();
canvas.translate(Math.min(0, scrollX), getPaddingTop());
canvas.rotate(90, 0, height);
mEdgeGlowLeft.setSize(getWidth(), height);
if (mEdgeGlowLeft.draw(canvas)) {
ViewCompat.postInvalidateOnAnimation(this);
}
canvas.restoreToCount(restoreCount);
}
if (!mEdgeGlowRight.isFinished()) {
final int restoreCount = canvas.save();
final int width = getWidth();
final int height = getHeight() - getPaddingTop() - getPaddingBottom();
canvas.translate(Math.max(getScrollRange(), scrollX) + width,
-height + getPaddingTop());
canvas.rotate(90, 0, height);
mEdgeGlowRight.setSize(width, height);
if (mEdgeGlowRight.draw(canvas)) {
ViewCompat.postInvalidateOnAnimation(this);
}
canvas.restoreToCount(restoreCount);
}
}
}
private static int clamp(int n, int my, int child) {
if (my >= child || n < 0) {
/* my >= child is this case:
* |--------------- me ---------------|
* |------ child ------|
* or
* |--------------- me ---------------|
* |------ child ------|
* or
* |--------------- me ---------------|
* |------ child ------|
*
* n < 0 is this case:
* |------ me ------|
* |-------- child --------|
* |-- mScrollX --|
*/
return 0;
}
if ((my+n) > child) {
/* this case:
* |------ me ------|
* |------ child ------|
* |-- mScrollX --|
*/
return child-my;
}
return n;
}
@Override
protected void onRestoreInstanceState(Parcelable state) {
SavedState ss = (SavedState) state;
super.onRestoreInstanceState(ss.getSuperState());
mSavedState = ss;
requestLayout();
}
@Override
protected Parcelable onSaveInstanceState() {
Parcelable superState = super.onSaveInstanceState();
SavedState ss = new SavedState(superState);
ss.scrollPosition = getScrollX();
return ss;
}
static class SavedState extends BaseSavedState {
public int scrollPosition;
SavedState(Parcelable superState) {
super(superState);
}
public SavedState(Parcel source) {
super(source);
scrollPosition = source.readInt();
}
@Override
public void writeToParcel(Parcel dest, int flags) {
super.writeToParcel(dest, flags);
dest.writeInt(scrollPosition);
}
@Override
public String toString() {
return "HorizontalScrollView.SavedState{"
+ Integer.toHexString(System.identityHashCode(this))
+ " scrollPosition=" + scrollPosition + "}";
}
public static final Parcelable.Creator<SavedState> CREATOR
= new Parcelable.Creator<SavedState>() {
public SavedState createFromParcel(Parcel in) {
return new SavedState(in);
}
public SavedState[] newArray(int size) {
return new SavedState[size];
}
};
}
static class AccessibilityDelegate extends AccessibilityDelegateCompat {
@Override
public boolean performAccessibilityAction(View host, int action, Bundle arguments) {
if (super.performAccessibilityAction(host, action, arguments)) {
return true;
}
final NestHorizontalScrollView nsvHost = (NestHorizontalScrollView) host;
if (!nsvHost.isEnabled()) {
return false;
}
switch (action) {
case AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD: {
final int viewportWidth = nsvHost.getWidth() - nsvHost.getPaddingRight()
- nsvHost.getPaddingLeft();
final int targetScrollX = Math.min(nsvHost.getScrollX() + viewportWidth,
nsvHost.getScrollRange());
if (targetScrollX != nsvHost.getScrollX()) {
nsvHost.smoothScrollTo(targetScrollX, 0);
return true;
}
}
return false;
case AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD: {
final int viewportWidth = nsvHost.getWidth() - nsvHost.getPaddingRight()
- nsvHost.getPaddingLeft();
final int targetScrollX = Math.max(nsvHost.getScrollX() - viewportWidth, 0);
if (targetScrollX != nsvHost.getScrollX()) {
nsvHost.smoothScrollTo(0, targetScrollX);
return true;
}
}
return false;
}
return false;
}
@Override
public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info) {
super.onInitializeAccessibilityNodeInfo(host, info);
final NestHorizontalScrollView nsvHost = (NestHorizontalScrollView) host;
info.setClassName(ScrollView.class.getName());
if (nsvHost.isEnabled()) {
final int scrollRange = nsvHost.getScrollRange();
if (scrollRange > 0) {
info.setScrollable(true);
if (nsvHost.getScrollX() > 0) {
info.addAction(AccessibilityNodeInfoCompat.ACTION_SCROLL_BACKWARD);
}
if (nsvHost.getScrollX() < scrollRange) {
info.addAction(AccessibilityNodeInfoCompat.ACTION_SCROLL_FORWARD);
}
}
}
}
@Override
public void onInitializeAccessibilityEvent(View host, AccessibilityEvent event) {
super.onInitializeAccessibilityEvent(host, event);
final NestHorizontalScrollView nsvHost = (NestHorizontalScrollView) host;
event.setClassName(ScrollView.class.getName());
final AccessibilityRecordCompat record = AccessibilityEventCompat.asRecord(event);
final boolean scrollable = nsvHost.getScrollRange() > 0;
record.setScrollable(scrollable);
record.setScrollX(nsvHost.getScrollX());
record.setScrollY(nsvHost.getScrollY());
record.setMaxScrollX(nsvHost.getScrollRange());
record.setMaxScrollY(nsvHost.getScrollY());
}
}
}