/*
* Copyright (C) 2013 The Android Open Source Project
* Copyright 2013 Niek Haarman
*
* 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 com.nhaarman.listviewanimations.widget;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewGroup;
import android.view.ViewTreeObserver;
import android.widget.AbsListView;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.HeaderViewListAdapter;
import android.widget.ListAdapter;
import android.widget.ListView;
import com.nhaarman.listviewanimations.itemmanipulation.swipedismiss.SwipeOnTouchListener;
import com.nineoldandroids.animation.Animator;
import com.nineoldandroids.animation.AnimatorListenerAdapter;
import com.nineoldandroids.animation.ObjectAnimator;
import com.nineoldandroids.animation.TypeEvaluator;
import com.nineoldandroids.animation.ValueAnimator;
import com.nineoldandroids.view.ViewHelper;
/**
* The DynamicListView is an extension of {@link ListView} that supports cell dragging
* and swapping.
* </p>
* Make sure your adapter has stable ids, and override {@link ListAdapter#hasStableIds()} to return true.</br>
* </p>
* This layout is in charge of positioning the hover cell in the correct location
* on the screen in response to user touch events. It uses the position of the
* hover cell to determine when two cells should be swapped. If two cells should
* be swapped, all the corresponding data set and layout changes are handled here.
* </p>
* If no cell is selected, all the touch events are passed down to the ListView
* and behave normally. If one of the items in the ListView experiences a
* long press event, the contents of its current visible state are captured as
* a bitmap and its visibility is set to INVISIBLE. A hover cell is then created and
* added to this layout as an overlaying BitmapDrawable above the ListView. Once the
* hover cell is translated some distance to signify an item swap, a data set change
* accompanied by animation takes place. When the user releases the hover cell,
* it animates into its corresponding position in the ListView.
* </p>
* When the hover cell is either above or below the bounds of the ListView, this
* ListView also scrolls on its own so as to reveal additional content.
* </p>
* See http://youtu.be/_BZIvjMgH-Q
*/
public class DynamicListView extends ListView {
private int mOriginalTranscriptMode;
public interface OnHoverCellListener {
public Drawable onHoverCellCreated(Drawable hoverCellDrawable);
}
/**
* Implement this interface to be notified of ordering changes. Call {@link #setOnItemMovedListener(com.nhaarman.listviewanimations.widget.DynamicListView.OnItemMovedListener)}.
*/
public interface OnItemMovedListener {
/**
* Called after an item is dropped and moved.
*
* @param newPosition the new position of the item.
*/
public void onItemMoved(int newPosition);
}
private final int SMOOTH_SCROLL_AMOUNT_AT_EDGE = 15;
private final int MOVE_DURATION = 150;
private int mLastEventY = -1, mLastEventX = -1;
private int mDownY = -1;
private int mDownX = -1;
private int mTotalOffset = 0;
private boolean mCellIsMobile = false;
private boolean mIsMobileScrolling = false;
private int mSmoothScrollAmountAtEdge = 0;
private final int INVALID_ID = -1;
private long mAboveItemId = INVALID_ID;
private long mMobileItemId = INVALID_ID;
private long mBelowItemId = INVALID_ID;
private Drawable mHoverCell;
private Rect mHoverCellCurrentBounds;
private Rect mHoverCellOriginalBounds;
private final int INVALID_POINTER_ID = -1;
private int mActivePointerId = INVALID_POINTER_ID;
private boolean mIsWaitingForScrollFinish = false;
private int mScrollState = OnScrollListener.SCROLL_STATE_IDLE;
private OnTouchListener mOnTouchListener;
private boolean mIsParentHorizontalScrollContainer;
private int mResIdOfDynamicTouchChild;
private boolean mDynamicTouchChildTouched;
private int mSlop;
private boolean mSkipCallingOnTouchListener;
private OnHoverCellListener mOnHoverCellListener;
private OnItemMovedListener mOnItemMovedListener;
private int mLastMovedToIndex;
public DynamicListView(Context context) {
super(context);
init(context);
}
public DynamicListView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init(context);
}
public DynamicListView(Context context, AttributeSet attrs) {
super(context, attrs);
init(context);
}
public void init(Context context) {
setOnItemLongClickListener(mOnItemLongClickListener);
setOnScrollListener(mScrollListener);
DisplayMetrics metrics = context.getResources().getDisplayMetrics();
mSmoothScrollAmountAtEdge = (int) (SMOOTH_SCROLL_AMOUNT_AT_EDGE / metrics.density);
ViewConfiguration vc = ViewConfiguration.get(getContext());
mSlop = vc.getScaledTouchSlop();
}
public void setAdapter(BaseAdapter adapter) {
super.setAdapter(adapter);
}
@Override
@Deprecated
/**
* @deprecated use #setAdapter(BaseAdapter) instead.
*/
public void setAdapter(ListAdapter adapter) {
if (!(adapter instanceof BaseAdapter)) {
throw new IllegalArgumentException("DynamicListView needs a BaseAdapter!");
}
super.setAdapter(adapter);
}
/**
* Listens for long clicks on any items in the listview. When a cell has
* been selected, the hover cell is created and set up.
*/
private OnItemLongClickListener mOnItemLongClickListener = new OnItemLongClickListener() {
public boolean onItemLongClick(AdapterView<?> arg0, View arg1, int pos, long id) {
if (mResIdOfDynamicTouchChild == 0) {
mDynamicTouchChildTouched = true;
makeCellMobile();
return true;
}
return false;
}
};
private void makeCellMobile() {
int position = pointToPosition(mDownX, mDownY);
int itemNum = position - getFirstVisiblePosition();
View selectedView = getChildAt(itemNum);
if (selectedView == null || position < getHeaderViewsCount() || position >= getAdapter().getCount() - getHeaderViewsCount()) {
return;
}
mOriginalTranscriptMode = getTranscriptMode();
setTranscriptMode(TRANSCRIPT_MODE_NORMAL);
mTotalOffset = 0;
mMobileItemId = getAdapter().getItemId(position);
mHoverCell = getAndAddHoverView(selectedView);
if (mOnHoverCellListener != null) {
mHoverCell = mOnHoverCellListener.onHoverCellCreated(mHoverCell);
}
selectedView.setVisibility(INVISIBLE);
mCellIsMobile = true;
getParent().requestDisallowInterceptTouchEvent(true);
updateNeighborViewsForId(mMobileItemId);
}
/**
* Creates the hover cell with the appropriate bitmap and of appropriate
* size. The hover cell's BitmapDrawable is drawn on top of the bitmap every
* single time an invalidate call is made.
*/
private BitmapDrawable getAndAddHoverView(View v) {
int w = v.getWidth();
int h = v.getHeight();
int top = v.getTop();
int left = v.getLeft();
Bitmap b = getBitmapFromView(v);
BitmapDrawable drawable = new BitmapDrawable(getResources(), b);
mHoverCellOriginalBounds = new Rect(left, top, left + w, top + h);
mHoverCellCurrentBounds = new Rect(mHoverCellOriginalBounds);
drawable.setBounds(mHoverCellCurrentBounds);
return drawable;
}
/**
* Returns a bitmap showing a screenshot of the view passed in.
*/
private Bitmap getBitmapFromView(View v) {
Bitmap bitmap = Bitmap.createBitmap(v.getWidth(), v.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
v.draw(canvas);
return bitmap;
}
/**
* Stores a reference to the views above and below the item currently
* corresponding to the hover cell. It is important to note that if this
* item is either at the top or bottom of the list, mAboveItemId or mBelowItemId
* may be invalid.
*/
private void updateNeighborViewsForId(long itemId) {
int position = getPositionForId(itemId);
ListAdapter adapter = getAdapter();
if (!adapter.hasStableIds()) {
throw new IllegalStateException("Adapter doesn't have stable ids! Make sure your adapter has stable ids, and override hasStableIds() to return true.");
}
mAboveItemId = position - 1 >= 0 ? adapter.getItemId(position - 1) : INVALID_ROW_ID;
mBelowItemId = position + 1 < adapter.getCount() ? adapter.getItemId(position + 1) : INVALID_ROW_ID;
}
/**
* Retrieves the view in the list corresponding to itemId
*/
private View getViewForId(long itemId) {
int firstVisiblePosition = getFirstVisiblePosition();
ListAdapter adapter = getAdapter();
if (!adapter.hasStableIds()) {
throw new IllegalStateException("Adapter doesn't have stable ids! Make sure your adapter has stable ids, and override hasStableIds() to return true.");
}
for (int i = 0; i < getChildCount(); i++) {
View v = getChildAt(i);
int position = firstVisiblePosition + i;
long id = adapter.getItemId(position);
if (id == itemId) {
return v;
}
}
return null;
}
/**
* Retrieves the position in the list corresponding to itemId
*/
private int getPositionForId(long itemId) {
View v = getViewForId(itemId);
if (v == null) {
return -1;
} else {
return getPositionForView(v);
}
}
/**
* dispatchDraw gets invoked when all the child views are about to be drawn.
* By overriding this method, the hover cell (BitmapDrawable) can be drawn
* over the listview's items whenever the listview is redrawn.
*/
@Override
protected void dispatchDraw(Canvas canvas) {
super.dispatchDraw(canvas);
if (mHoverCell != null) {
mHoverCell.draw(canvas);
}
}
@Override
public void setOnTouchListener(OnTouchListener l) {
mOnTouchListener = l;
}
public void setOnHoverCellListener(OnHoverCellListener onHoverCellListener) {
mOnHoverCellListener = onHoverCellListener;
}
private Rect getChildViewRect(View parentView, View childView) {
final Rect childRect = new Rect(childView.getLeft(), childView.getTop(), childView.getRight(), childView.getBottom());
if (parentView == childView) {
return childRect;
}
ViewGroup parent;
while ((parent = (ViewGroup) childView.getParent()) != parentView) {
childRect.offset(parent.getLeft(), parent.getTop());
childView = parent;
}
return childRect;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
if (mSkipCallingOnTouchListener) {
return super.onTouchEvent(event);
}
if (mOnTouchListener instanceof SwipeOnTouchListener) {
if (((SwipeOnTouchListener) mOnTouchListener).isSwiping()) {
mSkipCallingOnTouchListener = true;
boolean retVal = mOnTouchListener.onTouch(this, event);
mSkipCallingOnTouchListener = false;
return retVal || super.onTouchEvent(event);
}
}
switch (event.getAction() & MotionEvent.ACTION_MASK) {
case MotionEvent.ACTION_DOWN:
mDownX = (int) event.getX();
mDownY = (int) event.getY();
mActivePointerId = event.getPointerId(0);
mDynamicTouchChildTouched = false;
if (mResIdOfDynamicTouchChild != 0) {
mIsParentHorizontalScrollContainer = false;
int position = pointToPosition(mDownX, mDownY);
int childNum = (position != INVALID_POSITION) ? position - getFirstVisiblePosition() : -1;
View itemView = (childNum >= 0) ? getChildAt(childNum) : null;
View childView = (itemView != null) ? itemView.findViewById(mResIdOfDynamicTouchChild) : null;
if (childView != null) {
final Rect childRect = getChildViewRect(this, childView);
if (childRect.contains(mDownX, mDownY)) {
mDynamicTouchChildTouched = true;
getParent().requestDisallowInterceptTouchEvent(true);
}
}
}
if (mIsParentHorizontalScrollContainer) {
// Do it now and don't wait until the user moves more than the
// slop factor.
getParent().requestDisallowInterceptTouchEvent(true);
}
break;
case MotionEvent.ACTION_MOVE:
if (mActivePointerId == INVALID_POINTER_ID) {
break;
}
int pointerIndex = event.findPointerIndex(mActivePointerId);
mLastEventY = (int) event.getY(pointerIndex);
mLastEventX = (int) event.getX(pointerIndex);
int deltaY = mLastEventY - mDownY;
int deltaX = mLastEventX - mDownX;
if (!mCellIsMobile && mDynamicTouchChildTouched) {
if (Math.abs(deltaY) > mSlop && Math.abs(deltaY) > Math.abs(deltaX)) {
makeCellMobile();
// Cancel ListView's touch (un-highlighting the item)
MotionEvent cancelEvent = MotionEvent.obtain(event);
cancelEvent.setAction(MotionEvent.ACTION_CANCEL | (event.getActionIndex() << MotionEvent.ACTION_POINTER_INDEX_SHIFT));
super.onTouchEvent(cancelEvent);
cancelEvent.recycle();
}
}
if (mCellIsMobile) {
mHoverCellCurrentBounds.offsetTo(mHoverCellOriginalBounds.left, mHoverCellOriginalBounds.top + deltaY + mTotalOffset);
mHoverCell.setBounds(mHoverCellCurrentBounds);
invalidate();
handleCellSwitch();
mIsMobileScrolling = false;
handleMobileCellScroll();
}
break;
case MotionEvent.ACTION_UP:
mDynamicTouchChildTouched = false;
touchEventsEnded();
break;
case MotionEvent.ACTION_CANCEL:
mDynamicTouchChildTouched = false;
touchEventsCancelled();
break;
case MotionEvent.ACTION_POINTER_UP:
/*
* If a multitouch event took place and the original touch dictating
* the movement of the hover cell has ended, then the dragging event
* ends and the hover cell is animated to its corresponding position
* in the listview.
*/
pointerIndex = (event.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >> MotionEvent.ACTION_POINTER_INDEX_SHIFT;
final int pointerId = event.getPointerId(pointerIndex);
if (pointerId == mActivePointerId) {
mDynamicTouchChildTouched = false;
touchEventsEnded();
}
break;
default:
break;
}
if (mCellIsMobile) {
return false;
} else if (mOnTouchListener != null) {
mSkipCallingOnTouchListener = true;
boolean retVal = mOnTouchListener.onTouch(this, event);
mSkipCallingOnTouchListener = false;
if (retVal) {
return true;
}
}
return super.onTouchEvent(event);
}
/**
* This method determines whether the hover cell has been shifted far enough
* to invoke a cell swap. If so, then the respective cell swap candidate is
* determined and the data set is changed. Upon posting a notification of the
* data set change, a layout is invoked to place the cells in the right place.
* Using a ViewTreeObserver and a corresponding OnPreDrawListener, we can
* offset the cell being swapped to where it previously was and then animate it to
* its new position.
*/
private void handleCellSwitch() {
final int deltaY = mLastEventY - mDownY;
int deltaYTotal = mHoverCellOriginalBounds.top + mTotalOffset + deltaY;
View belowView = getViewForId(mBelowItemId);
View mobileView = getViewForId(mMobileItemId);
View aboveView = getViewForId(mAboveItemId);
boolean isBelow = (belowView != null) && (deltaYTotal > belowView.getTop());
boolean isAbove = (aboveView != null) && (deltaYTotal < aboveView.getTop());
if (isBelow || isAbove) {
final long switchItemId = isBelow ? mBelowItemId : mAboveItemId;
View switchView = isBelow ? belowView : aboveView;
final int originalItem = getPositionForView(mobileView);
if (switchView == null) {
updateNeighborViewsForId(mMobileItemId);
return;
}
if (getPositionForView(switchView) < getHeaderViewsCount()) {
return;
}
swapElements(originalItem, getPositionForView(switchView));
BaseAdapter adapter;
if (getAdapter() instanceof HeaderViewListAdapter) {
adapter = (BaseAdapter) ((HeaderViewListAdapter) getAdapter()).getWrappedAdapter();
} else {
adapter = (BaseAdapter) getAdapter();
}
adapter.notifyDataSetChanged();
mDownY = mLastEventY;
mDownX = mLastEventX;
final int switchViewStartTop = switchView.getTop();
mobileView.setVisibility(View.VISIBLE);
switchView.setVisibility(View.INVISIBLE);
updateNeighborViewsForId(mMobileItemId);
final ViewTreeObserver observer = getViewTreeObserver();
observer.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
public boolean onPreDraw() {
observer.removeOnPreDrawListener(this);
View switchView = getViewForId(switchItemId);
mTotalOffset += deltaY;
int switchViewNewTop = switchView.getTop();
int delta = switchViewStartTop - switchViewNewTop;
ViewHelper.setTranslationY(switchView, delta);
ObjectAnimator animator = ObjectAnimator.ofFloat(switchView, "translationY", 0);
animator.setDuration(MOVE_DURATION);
animator.start();
return true;
}
});
}
}
private void swapElements(int indexOne, int indexTwo) {
mLastMovedToIndex = indexTwo;
ListAdapter adapter = getAdapter();
if (adapter instanceof HeaderViewListAdapter) {
adapter = ((HeaderViewListAdapter) adapter).getWrappedAdapter();
}
if (adapter instanceof Swappable) {
((Swappable) adapter).swapItems(indexOne - getHeaderViewsCount(), indexTwo - getHeaderViewsCount());
}
}
/**
* Resets all the appropriate fields to a default state while also animating
* the hover cell back to its correct location.
*/
private void touchEventsEnded() {
final View mobileView = getViewForId(mMobileItemId);
if (mCellIsMobile || mIsWaitingForScrollFinish) {
mCellIsMobile = false;
mIsWaitingForScrollFinish = false;
mIsMobileScrolling = false;
mActivePointerId = INVALID_POINTER_ID;
/* Restore the transcript mode */
setTranscriptMode(mOriginalTranscriptMode);
// If the autoscroller has not completed scrolling, we need to wait
// for it to
// finish in order to determine the final location of where the
// hover cell
// should be animated to.
if (mScrollState != OnScrollListener.SCROLL_STATE_IDLE) {
mIsWaitingForScrollFinish = true;
return;
}
mHoverCellCurrentBounds.offsetTo(mHoverCellOriginalBounds.left, mobileView.getTop());
ObjectAnimator hoverViewAnimator = ObjectAnimator.ofObject(mHoverCell, "bounds", sBoundEvaluator, mHoverCellCurrentBounds);
hoverViewAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator valueAnimator) {
invalidate();
}
});
hoverViewAnimator.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationStart(Animator animation) {
setEnabled(false);
}
@Override
public void onAnimationEnd(Animator animation) {
mAboveItemId = INVALID_ID;
mMobileItemId = INVALID_ID;
mBelowItemId = INVALID_ID;
mobileView.setVisibility(VISIBLE);
mHoverCell = null;
setEnabled(true);
invalidate();
if (mOnItemMovedListener != null) {
mOnItemMovedListener.onItemMoved(mLastMovedToIndex - getHeaderViewsCount());
}
}
});
hoverViewAnimator.start();
} else {
touchEventsCancelled();
}
}
/**
* Resets all the appropriate fields to a default state.
*/
private void touchEventsCancelled() {
View mobileView = getViewForId(mMobileItemId);
if (mCellIsMobile) {
mAboveItemId = INVALID_ID;
mMobileItemId = INVALID_ID;
mBelowItemId = INVALID_ID;
mobileView.setVisibility(VISIBLE);
mHoverCell = null;
invalidate();
}
mCellIsMobile = false;
mIsMobileScrolling = false;
mActivePointerId = INVALID_POINTER_ID;
}
/**
* This TypeEvaluator is used to animate the BitmapDrawable back to its
* final location when the user lifts his finger by modifying the
* BitmapDrawable's bounds.
*/
private final static TypeEvaluator<Rect> sBoundEvaluator = new TypeEvaluator<Rect>() {
public Rect evaluate(float fraction, Rect startValue, Rect endValue) {
return new Rect(interpolate(startValue.left, endValue.left, fraction), interpolate(startValue.top, endValue.top, fraction), interpolate(startValue.right, endValue.right, fraction),
interpolate(startValue.bottom, endValue.bottom, fraction));
}
public int interpolate(int start, int end, float fraction) {
return (int) (start + fraction * (end - start));
}
};
/**
* Determines whether this listview is in a scrolling state invoked
* by the fact that the hover cell is out of the bounds of the listview;
*/
private void handleMobileCellScroll() {
mIsMobileScrolling = handleMobileCellScroll(mHoverCellCurrentBounds);
}
/**
* This method is in charge of determining if the hover cell is above
* or below the bounds of the listview. If so, the listview does an appropriate
* upward or downward smooth scroll so as to reveal new items.
*/
private boolean handleMobileCellScroll(Rect r) {
int offset = computeVerticalScrollOffset();
int height = getHeight();
int extent = computeVerticalScrollExtent();
int range = computeVerticalScrollRange();
int hoverViewTop = r.top;
int hoverHeight = r.height();
if (hoverViewTop <= 0 && offset > 0) {
smoothScrollBy(-mSmoothScrollAmountAtEdge, 0);
return true;
}
if (hoverViewTop + hoverHeight >= height && (offset + extent) < range) {
smoothScrollBy(mSmoothScrollAmountAtEdge, 0);
return true;
}
return false;
}
public void setIsParentHorizontalScrollContainer(boolean isParentHorizontalScrollContainer) {
mIsParentHorizontalScrollContainer = (mResIdOfDynamicTouchChild == 0) && isParentHorizontalScrollContainer;
}
public boolean isParentHorizontalScrollContainer() {
return mIsParentHorizontalScrollContainer;
}
public void setDynamicTouchChild(int childResId) {
mResIdOfDynamicTouchChild = childResId;
if (childResId != 0) {
setIsParentHorizontalScrollContainer(false);
}
}
/**
* This scroll listener is added to the listview in order to handle cell swapping
* when the cell is either at the top or bottom edge of the listview. If the hover
* cell is at either edge of the listview, the listview will begin scrolling. As
* scrolling takes place, the listview continuously checks if new cells became visible
* and determines whether they are potential candidates for a cell swap.
*/
private OnScrollListener mScrollListener = new OnScrollListener() {
private int mPreviousFirstVisibleItem = -1;
private int mPreviousVisibleItemCount = -1;
private int mCurrentFirstVisibleItem;
private int mCurrentVisibleItemCount;
private int mCurrentScrollState;
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
mCurrentFirstVisibleItem = firstVisibleItem;
mCurrentVisibleItemCount = visibleItemCount;
mPreviousFirstVisibleItem = (mPreviousFirstVisibleItem == -1) ? mCurrentFirstVisibleItem : mPreviousFirstVisibleItem;
mPreviousVisibleItemCount = (mPreviousVisibleItemCount == -1) ? mCurrentVisibleItemCount : mPreviousVisibleItemCount;
checkAndHandleFirstVisibleCellChange();
checkAndHandleLastVisibleCellChange();
mPreviousFirstVisibleItem = mCurrentFirstVisibleItem;
mPreviousVisibleItemCount = mCurrentVisibleItemCount;
}
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
mCurrentScrollState = scrollState;
mScrollState = scrollState;
isScrollCompleted();
}
/**
* This method is in charge of invoking 1 of 2 actions. Firstly, if the listview
* is in a state of scrolling invoked by the hover cell being outside the bounds
* of the listview, then this scrolling event is continued. Secondly, if the hover
* cell has already been released, this invokes the animation for the hover cell
* to return to its correct position after the listview has entered an idle scroll
* state.
*/
private void isScrollCompleted() {
if (mCurrentVisibleItemCount > 0 && mCurrentScrollState == SCROLL_STATE_IDLE) {
if (mCellIsMobile && mIsMobileScrolling) {
handleMobileCellScroll();
} else if (mIsWaitingForScrollFinish) {
touchEventsEnded();
}
}
}
/**
* Determines if the listview scrolled up enough to reveal a new cell at the
* top of the list. If so, then the appropriate parameters are updated.
*/
public void checkAndHandleFirstVisibleCellChange() {
if (mCurrentFirstVisibleItem != mPreviousFirstVisibleItem) {
if (mCellIsMobile && mMobileItemId != INVALID_ID) {
updateNeighborViewsForId(mMobileItemId);
handleCellSwitch();
}
}
}
/**
* Determines if the listview scrolled down enough to reveal a new cell at the
* bottom of the list. If so, then the appropriate parameters are updated.
*/
public void checkAndHandleLastVisibleCellChange() {
int currentLastVisibleItem = mCurrentFirstVisibleItem + mCurrentVisibleItemCount;
int previousLastVisibleItem = mPreviousFirstVisibleItem + mPreviousVisibleItemCount;
if (currentLastVisibleItem != previousLastVisibleItem) {
if (mCellIsMobile && mMobileItemId != INVALID_ID) {
updateNeighborViewsForId(mMobileItemId);
handleCellSwitch();
}
}
}
};
/**
* Set the {@link com.nhaarman.listviewanimations.widget.DynamicListView.OnItemMovedListener} to be notified when an item is dropped.
*/
public void setOnItemMovedListener(OnItemMovedListener onItemMovedListener) {
this.mOnItemMovedListener = onItemMovedListener;
}
/**
* Interface, usually implemented by a {@link com.nhaarman.listviewanimations.BaseAdapterDecorator},
* that indicates that it can swap the visual position of two list items.
*
* @author Anton Spaans on 9/11/13.
*/
public interface Swappable {
/**
* Swaps the item on the first adapter position with the item on the second adapter position.
* Be sure to call {@link android.widget.BaseAdapter#notifyDataSetChanged()} if appropriate when implementing this method.
*
* @param positionOne First adapter position.
* @param positionTwo Second adapter position.
*/
public void swapItems(int positionOne, int positionTwo);
}
}