DropTargetBar.java revision 0f76b56865bd7b63bd21d53aaac47300396aa38f 
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
17package com.android.launcher3;
18
19import android.animation.TimeInterpolator;
20import android.content.Context;
21import android.util.AttributeSet;
22import android.view.View;
23import android.view.ViewDebug;
24import android.view.ViewGroup;
25import android.view.ViewPropertyAnimator;
26import android.view.accessibility.AccessibilityManager;
27import android.view.animation.AccelerateInterpolator;
28import android.widget.LinearLayout;
29
30import com.android.launcher3.dragndrop.DragController;
31import com.android.launcher3.dragndrop.DragOptions;
32
33/*
34 * The top bar containing various drop targets: Delete/App Info/Uninstall.
35 */
36public 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