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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 package com.android.launcher3;
     18 
     19 import android.animation.TimeInterpolator;
     20 import android.content.Context;
     21 import android.util.AttributeSet;
     22 import android.view.View;
     23 import android.view.ViewDebug;
     24 import android.view.ViewGroup;
     25 import android.view.ViewPropertyAnimator;
     26 import android.view.accessibility.AccessibilityManager;
     27 import android.view.animation.AccelerateInterpolator;
     28 import android.widget.LinearLayout;
     29 
     30 import com.android.launcher3.dragndrop.DragController;
     31 import com.android.launcher3.dragndrop.DragOptions;
     32 
     33 /*
     34  * The top bar containing various drop targets: Delete/App Info/Uninstall.
     35  */
     36 public class DropTargetBar extends LinearLayout implements DragController.DragListener {
     37 
     38     protected static final int DEFAULT_DRAG_FADE_DURATION = 175;
     39     protected static final TimeInterpolator DEFAULT_INTERPOLATOR = new AccelerateInterpolator();
     40 
     41     private final Runnable mFadeAnimationEndRunnable = new Runnable() {
     42 
     43         @Override
     44         public void run() {
     45             AccessibilityManager am = (AccessibilityManager)
     46                     getContext().getSystemService(Context.ACCESSIBILITY_SERVICE);
     47             boolean accessibilityEnabled = am.isEnabled();
     48             AlphaUpdateListener.updateVisibility(DropTargetBar.this, accessibilityEnabled);
     49         }
     50     };
     51 
     52     @ViewDebug.ExportedProperty(category = "launcher")
     53     protected boolean mDeferOnDragEnd;
     54 
     55     @ViewDebug.ExportedProperty(category = "launcher")
     56     protected boolean mVisible = false;
     57 
     58     private ViewPropertyAnimator mCurrentAnimation;
     59 
     60     public DropTargetBar(Context context, AttributeSet attrs) {
     61         super(context, attrs);
     62     }
     63 
     64     public DropTargetBar(Context context, AttributeSet attrs, int defStyle) {
     65         super(context, attrs, defStyle);
     66     }
     67 
     68     @Override
     69     protected void onFinishInflate() {
     70         super.onFinishInflate();
     71 
     72         // Initialize with hidden state
     73         setAlpha(0f);
     74     }
     75 
     76     public void setup(DragController dragController) {
     77         dragController.addDragListener(this);
     78         setupButtonDropTarget(this, dragController);
     79     }
     80 
     81     private void setupButtonDropTarget(View view, DragController dragController) {
     82         if (view instanceof ButtonDropTarget) {
     83             ButtonDropTarget bdt = (ButtonDropTarget) view;
     84             bdt.setDropTargetBar(this);
     85             dragController.addDragListener(bdt);
     86             dragController.addDropTarget(bdt);
     87         } else if (view instanceof ViewGroup) {
     88             ViewGroup vg = (ViewGroup) view;
     89             for (int i = vg.getChildCount() - 1; i >= 0; i--) {
     90                 setupButtonDropTarget(vg.getChildAt(i), dragController);
     91             }
     92         }
     93     }
     94 
     95     private void animateToVisibility(boolean isVisible) {
     96         if (mVisible != isVisible) {
     97             mVisible = isVisible;
     98 
     99             // Cancel any existing animation
    100             if (mCurrentAnimation != null) {
    101                 mCurrentAnimation.cancel();
    102                 mCurrentAnimation = null;
    103             }
    104 
    105             float finalAlpha = mVisible ? 1 : 0;
    106             if (Float.compare(getAlpha(), finalAlpha) != 0) {
    107                 setVisibility(View.VISIBLE);
    108                 mCurrentAnimation = animate().alpha(finalAlpha)
    109                         .setInterpolator(DEFAULT_INTERPOLATOR)
    110                         .setDuration(DEFAULT_DRAG_FADE_DURATION)
    111                         .withEndAction(mFadeAnimationEndRunnable);
    112             }
    113 
    114         }
    115     }
    116 
    117     /*
    118      * DragController.DragListener implementation
    119      */
    120     @Override
    121     public void onDragStart(DropTarget.DragObject dragObject, DragOptions options) {
    122         animateToVisibility(true);
    123     }
    124 
    125     /**
    126      * This is called to defer hiding the delete drop target until the drop animation has completed,
    127      * instead of hiding immediately when the drag has ended.
    128      */
    129     protected void deferOnDragEnd() {
    130         mDeferOnDragEnd = true;
    131     }
    132 
    133     @Override
    134     public void onDragEnd() {
    135         if (!mDeferOnDragEnd) {
    136             animateToVisibility(false);
    137         } else {
    138             mDeferOnDragEnd = false;
    139         }
    140     }
    141 }
    142