681 lines
26 KiB
Java
681 lines
26 KiB
Java
/*
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* Copyright (C) 2013 The Android Open Source Project
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package org.xbmc.kore.ui.viewgroups;
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import android.animation.Animator;
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import android.animation.AnimatorListenerAdapter;
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import android.animation.ObjectAnimator;
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import android.animation.TypeEvaluator;
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import android.animation.ValueAnimator;
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import android.content.Context;
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import android.graphics.Bitmap;
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import android.graphics.Canvas;
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import android.graphics.Color;
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import android.graphics.Paint;
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import android.graphics.Rect;
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import android.graphics.drawable.BitmapDrawable;
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import android.util.AttributeSet;
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import android.util.DisplayMetrics;
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import android.util.SparseBooleanArray;
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import android.view.MotionEvent;
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import android.view.View;
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import android.view.ViewTreeObserver;
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import android.widget.AbsListView;
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import android.widget.AdapterView;
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import android.widget.BaseAdapter;
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import android.widget.ListAdapter;
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import android.widget.ListView;
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import org.xbmc.kore.utils.LogUtils;
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/**
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* The dynamic listview is an extension of listview that supports cell dragging
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* and swapping.
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*
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* This layout is in charge of positioning the hover cell in the correct location
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* on the screen in response to user touch events. It uses the position of the
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* hover cell to determine when two cells should be swapped. If two cells should
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* be swapped, all the corresponding data set and layout changes are handled here.
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*
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* If no cell is selected, all the touch events are passed down to the listview
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* and behave normally. If one of the items in the listview experiences a
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* long press event, the contents of its current visible state are captured as
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* a bitmap and its visibility is set to INVISIBLE. A hover cell is then created and
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* added to this layout as an overlaying BitmapDrawable above the listview. Once the
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* hover cell is translated some distance to signify an item onSwapItems, a data set change
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* accompanied by animation takes place. When the user releases the hover cell,
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* it animates into its corresponding position in the listview.
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*
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* When the hover cell is either above or below the bounds of the listview, this
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* listview also scrolls on its own so as to reveal additional content.
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*/
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/**
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* TODO Replace with RecyclerView and ItemTouchHelper
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* https://medium.com/@ipaulpro/drag-and-swipe-with-recyclerview-b9456d2b1aaf
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*/
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public class DynamicListView extends ListView {
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private static final String TAG = LogUtils.makeLogTag(DynamicListView.class);
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private final int SMOOTH_SCROLL_AMOUNT_AT_EDGE = 15;
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private final int MOVE_DURATION = 150;
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private final int LINE_THICKNESS = 15;
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private int mLastEventY = -1;
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private int mDownY = -1;
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private int mDownX = -1;
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private int mTotalOffset = 0;
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private boolean mCellIsMobile = false;
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private boolean mIsMobileScrolling = false;
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private int mSmoothScrollAmountAtEdge = 0;
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private final int INVALID_ID = -1;
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private long mAboveItemId = INVALID_ID;
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private long mMobileItemId = INVALID_ID;
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private long mBelowItemId = INVALID_ID;
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private BitmapDrawable mHoverCell;
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private Rect mHoverCellCurrentBounds;
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private Rect mHoverCellOriginalBounds;
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private int mOriginalPosition;
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private final int INVALID_POINTER_ID = -1;
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private int mActivePointerId = INVALID_POINTER_ID;
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private boolean mIsWaitingForScrollFinish = false;
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private int mScrollState = OnScrollListener.SCROLL_STATE_IDLE;
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private boolean itemBeingDragged;
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private boolean itemDraggingEnabled;
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public interface DynamicListAdapter extends ListAdapter {
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/**
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* Called when two items in the view need to be swapped.
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* @param positionOne position of first item
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* @param positionTwo position of second item.
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*/
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public void onSwapItems(int positionOne, int positionTwo);
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/**
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* Called when the user releases the dragged item
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* @param originalPostion original position of the dragged item
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* @param finalPosition new position of the dragged item
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*/
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public void onSwapFinished(int originalPostion, int finalPosition);
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}
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public DynamicListView(Context context) {
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super(context);
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init(context);
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}
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public DynamicListView(Context context, AttributeSet attrs, int defStyle) {
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super(context, attrs, defStyle);
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init(context);
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}
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public DynamicListView(Context context, AttributeSet attrs) {
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super(context, attrs);
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init(context);
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}
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public void init(Context context) {
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setOnItemLongClickListener(mOnItemLongClickListener);
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setOnScrollListener(mScrollListener);
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DisplayMetrics metrics = context.getResources().getDisplayMetrics();
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mSmoothScrollAmountAtEdge = (int)(SMOOTH_SCROLL_AMOUNT_AT_EDGE / metrics.density);
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}
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@Override
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public void setAdapter(ListAdapter adapter) {
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throw new ClassCastException(adapter.toString() + " must implement DynamicsListAdapter");
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}
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public void setAdapter(DynamicListAdapter adapter) {
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super.setAdapter(adapter);
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}
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public void enableItemDragging(boolean enable) {
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this.itemDraggingEnabled = enable;
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}
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/**
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* Use this to determine if an item is being repositioned in the list.
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* The data in the adapter must not be updated other then through the
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* callbacks {@link org.xbmc.kore.ui.viewgroups.DynamicListView.DynamicListAdapter#onSwapItems(int, int)}
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* and {@link org.xbmc.kore.ui.viewgroups.DynamicListView.DynamicListAdapter#onSwapFinished(int, int)}
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*
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* @return true if item is selected, false otherwise
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*/
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public boolean isItemBeingDragged() {
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return itemBeingDragged;
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}
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/**
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* Listens for long clicks on any items in the listview. When a cell has
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* been selected, the hover cell is created and set up.
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*/
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private AdapterView.OnItemLongClickListener mOnItemLongClickListener =
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new AdapterView.OnItemLongClickListener() {
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public boolean onItemLongClick(AdapterView<?> arg0, View arg1, int position, long id) {
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if (!itemDraggingEnabled)
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return false;
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mTotalOffset = 0;
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mOriginalPosition = position;
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int itemNum = position - getFirstVisiblePosition();
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View selectedView = getChildAt(itemNum);
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mMobileItemId = getAdapter().getItemId(position);
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mHoverCell = getAndAddHoverView(selectedView);
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selectedView.setVisibility(INVISIBLE);
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mCellIsMobile = true;
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itemBeingDragged = true;
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updateNeighborViewsForID(mMobileItemId);
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return true;
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}
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};
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/**
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* Creates the hover cell with the appropriate bitmap and of appropriate
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* size. The hover cell's BitmapDrawable is drawn on top of the bitmap every
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* single time an invalidate call is made.
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*/
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private BitmapDrawable getAndAddHoverView(View v) {
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int w = v.getWidth();
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int h = v.getHeight();
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int top = v.getTop();
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int left = v.getLeft();
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Bitmap b = getBitmapWithBorder(v);
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BitmapDrawable drawable = new BitmapDrawable(getResources(), b);
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mHoverCellOriginalBounds = new Rect(left, top, left + w, top + h);
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mHoverCellCurrentBounds = new Rect(mHoverCellOriginalBounds);
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drawable.setBounds(mHoverCellCurrentBounds);
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return drawable;
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}
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/** Draws a black border over the screenshot of the view passed in. */
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private Bitmap getBitmapWithBorder(View v) {
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Bitmap bitmap = getBitmapFromView(v);
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Canvas can = new Canvas(bitmap);
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Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
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Paint paint = new Paint();
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paint.setStyle(Paint.Style.STROKE);
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paint.setStrokeWidth(LINE_THICKNESS);
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paint.setColor(Color.BLACK);
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can.drawBitmap(bitmap, 0, 0, null);
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can.drawRect(rect, paint);
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return bitmap;
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}
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/** Returns a bitmap showing a screenshot of the view passed in. */
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private Bitmap getBitmapFromView(View v) {
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Bitmap bitmap = Bitmap.createBitmap(v.getWidth(), v.getHeight(), Bitmap.Config.ARGB_8888);
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Canvas canvas = new Canvas(bitmap);
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v.draw(canvas);
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return bitmap;
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}
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/**
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* Stores a reference to the views above and below the item currently
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* corresponding to the hover cell. It is important to note that if this
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* item is either at the top or bottom of the list, mAboveItemId or mBelowItemId
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* may be invalid.
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*/
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private void updateNeighborViewsForID(long itemID) {
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int position = getPositionForID(itemID);
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ListAdapter adapter = getAdapter();
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mAboveItemId = adapter.getItemId(position - 1);
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mBelowItemId = adapter.getItemId(position + 1);
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}
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/** Retrieves the view in the list corresponding to itemID */
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public View getViewForID (long itemID) {
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int firstVisiblePosition = getFirstVisiblePosition();
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ListAdapter adapter = getAdapter();
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for(int i = 0; i < getChildCount(); i++) {
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View v = getChildAt(i);
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int position = firstVisiblePosition + i;
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long id = adapter.getItemId(position);
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if (id == itemID) {
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return v;
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}
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}
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return null;
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}
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/** Retrieves the position in the list corresponding to itemID */
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public int getPositionForID (long itemID) {
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View v = getViewForID(itemID);
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if (v == null) {
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return -1;
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} else {
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return getPositionForView(v);
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}
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}
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/**
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* dispatchDraw gets invoked when all the child views are about to be drawn.
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* By overriding this method, the hover cell (BitmapDrawable) can be drawn
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* over the listview's items whenever the listview is redrawn.
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*/
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@Override
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protected void dispatchDraw(Canvas canvas) {
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super.dispatchDraw(canvas);
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if (mHoverCell != null) {
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mHoverCell.draw(canvas);
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}
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}
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@Override
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public boolean onTouchEvent (MotionEvent event) {
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switch (event.getAction() & MotionEvent.ACTION_MASK) {
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case MotionEvent.ACTION_DOWN:
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mDownX = (int)event.getX();
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mDownY = (int)event.getY();
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mActivePointerId = event.getPointerId(0);
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break;
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case MotionEvent.ACTION_MOVE:
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if (mActivePointerId == INVALID_POINTER_ID) {
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break;
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}
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int pointerIndex = event.findPointerIndex(mActivePointerId);
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mLastEventY = (int) event.getY(pointerIndex);
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int deltaY = mLastEventY - mDownY;
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if (mCellIsMobile) {
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mHoverCellCurrentBounds.offsetTo(mHoverCellOriginalBounds.left,
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mHoverCellOriginalBounds.top + deltaY + mTotalOffset);
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mHoverCell.setBounds(mHoverCellCurrentBounds);
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invalidate();
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handleCellSwitch();
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mIsMobileScrolling = false;
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handleMobileCellScroll();
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return false;
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}
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break;
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case MotionEvent.ACTION_UP:
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touchEventsEnded();
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break;
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case MotionEvent.ACTION_CANCEL:
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touchEventsCancelled();
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break;
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case MotionEvent.ACTION_POINTER_UP:
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/* If a multitouch event took place and the original touch dictating
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* the movement of the hover cell has ended, then the dragging event
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* ends and the hover cell is animated to its corresponding position
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* in the listview. */
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pointerIndex = (event.getAction() & MotionEvent.ACTION_POINTER_INDEX_MASK) >>
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MotionEvent.ACTION_POINTER_INDEX_SHIFT;
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final int pointerId = event.getPointerId(pointerIndex);
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if (pointerId == mActivePointerId) {
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touchEventsEnded();
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}
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break;
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default:
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break;
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}
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return super.onTouchEvent(event);
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}
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/**
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* This method determines whether the hover cell has been shifted far enough
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* to invoke a cell onSwapItems. If so, then the respective cell onSwapItems candidate is
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* determined and the data set is changed. Upon posting a notification of the
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* data set change, a layout is invoked to place the cells in the right place.
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* Using a ViewTreeObserver and a corresponding OnPreDrawListener, we can
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* offset the cell being swapped to where it previously was and then animate it to
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* its new position.
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*/
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private void handleCellSwitch() {
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final int deltaY = mLastEventY - mDownY;
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int deltaYTotal = mHoverCellOriginalBounds.top + mTotalOffset + deltaY;
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View belowView = getViewForID(mBelowItemId);
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View mobileView = getViewForID(mMobileItemId);
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View aboveView = getViewForID(mAboveItemId);
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boolean isBelow = (belowView != null) && (deltaYTotal > belowView.getTop());
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boolean isAbove = (aboveView != null) && (deltaYTotal < aboveView.getTop());
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if (isBelow || isAbove) {
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final long switchItemID = isBelow ? mBelowItemId : mAboveItemId;
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View switchView = isBelow ? belowView : aboveView;
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if (switchView == null) {
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updateNeighborViewsForID(mMobileItemId);
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return;
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}
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int originalItem = getPositionForView(mobileView);
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int switchViewItem = getPositionForView(switchView);
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updateCheckedItemPositions(originalItem, switchViewItem);
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BaseAdapter adapter = (BaseAdapter) getAdapter();
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((DynamicListAdapter) adapter).onSwapItems(originalItem, switchViewItem);
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adapter.notifyDataSetChanged();
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mDownY = mLastEventY;
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final int switchViewStartTop = switchView.getTop();
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mobileView.setVisibility(View.VISIBLE);
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switchView.setVisibility(View.INVISIBLE);
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updateNeighborViewsForID(mMobileItemId);
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final ViewTreeObserver observer = getViewTreeObserver();
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observer.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
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public boolean onPreDraw() {
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observer.removeOnPreDrawListener(this);
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View switchView = getViewForID(switchItemID);
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mTotalOffset += deltaY;
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int switchViewNewTop = switchView.getTop();
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int delta = switchViewStartTop - switchViewNewTop;
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switchView.setTranslationY(delta);
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ObjectAnimator animator = ObjectAnimator.ofFloat(switchView,
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View.TRANSLATION_Y, 0);
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animator.setDuration(MOVE_DURATION);
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animator.start();
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return true;
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}
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});
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}
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}
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/**
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* Resets all the appropriate fields to a default state while also animating
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* the hover cell back to its correct location.
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*/
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private void touchEventsEnded () {
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itemBeingDragged = false;
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final View mobileView = getViewForID(mMobileItemId);
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if (mobileView == null) {
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mAboveItemId = INVALID_ID;
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mMobileItemId = INVALID_ID;
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mBelowItemId = INVALID_ID;
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mHoverCell = null;
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invalidate();
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return;
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}
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if (mCellIsMobile|| mIsWaitingForScrollFinish) {
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mCellIsMobile = false;
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mIsWaitingForScrollFinish = false;
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mIsMobileScrolling = false;
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mActivePointerId = INVALID_POINTER_ID;
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int finalPosition = getPositionForView(mobileView);
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if( finalPosition != mOriginalPosition ) {
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((DynamicListAdapter) getAdapter()).onSwapFinished(mOriginalPosition, finalPosition);
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}
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// If the autoscroller has not completed scrolling, we need to wait for it to
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// finish in order to determine the final location of where the hover cell
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// should be animated to.
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if (mScrollState != OnScrollListener.SCROLL_STATE_IDLE) {
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mIsWaitingForScrollFinish = true;
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return;
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}
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mHoverCellCurrentBounds.offsetTo(mHoverCellOriginalBounds.left, mobileView.getTop());
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ObjectAnimator hoverViewAnimator = ObjectAnimator.ofObject(mHoverCell, "bounds",
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sBoundEvaluator, mHoverCellCurrentBounds);
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hoverViewAnimator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
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@Override
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public void onAnimationUpdate(ValueAnimator valueAnimator) {
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invalidate();
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}
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});
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hoverViewAnimator.addListener(new AnimatorListenerAdapter() {
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@Override
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public void onAnimationStart(Animator animation) {
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setEnabled(false);
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}
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@Override
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public void onAnimationEnd(Animator animation) {
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mAboveItemId = INVALID_ID;
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mMobileItemId = INVALID_ID;
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mBelowItemId = INVALID_ID;
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mobileView.setVisibility(VISIBLE);
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mHoverCell = null;
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setEnabled(true);
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invalidate();
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}
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});
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hoverViewAnimator.start();
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} else {
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touchEventsCancelled();
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}
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}
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/**
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* Resets all the appropriate fields to a default state.
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*/
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private void touchEventsCancelled () {
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itemBeingDragged = false;
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View mobileView = getViewForID(mMobileItemId);
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if (mCellIsMobile) {
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mAboveItemId = INVALID_ID;
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mMobileItemId = INVALID_ID;
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mBelowItemId = INVALID_ID;
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mobileView.setVisibility(VISIBLE);
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mHoverCell = null;
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invalidate();
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}
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mCellIsMobile = false;
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mIsMobileScrolling = false;
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mActivePointerId = INVALID_POINTER_ID;
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}
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/**
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* When swapping items the checked item positions in the list may need to be updated
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* @param originalPosition
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* @param newPosition
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*/
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private void updateCheckedItemPositions(int originalPosition, int newPosition) {
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switch (getChoiceMode()) {
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case CHOICE_MODE_SINGLE:
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int checkPos = getCheckedItemPosition();
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if (checkPos == newPosition) {
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setItemChecked(originalPosition, true);
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} else if (checkPos == originalPosition) {
|
|
setItemChecked(newPosition, false);
|
|
}
|
|
break;
|
|
case CHOICE_MODE_MULTIPLE:
|
|
SparseBooleanArray checkedItems = getCheckedItemPositions();
|
|
setItemChecked(originalPosition, checkedItems.get(newPosition));
|
|
setItemChecked(newPosition, checkedItems.get(originalPosition));
|
|
}
|
|
}
|
|
|
|
/**
|
|
* 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.
|
|
*/
|
|
public 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;
|
|
}
|
|
|
|
/**
|
|
* 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 onSwapItems.
|
|
*/
|
|
private AbsListView.OnScrollListener mScrollListener = new AbsListView.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();
|
|
}
|
|
}
|
|
}
|
|
};
|
|
} |