UndoBarView.java revision 517e1bd25305d4e82d101a8c06be0119dde2eab3 
1/*
2 * Copyright (C) 2012 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.gallery3d.ui;
18
19import android.content.Context;
20import android.view.MotionEvent;
21
22import com.android.gallery3d.R;
23import com.android.gallery3d.common.Utils;
24import com.android.gallery3d.util.GalleryUtils;
25
26public class UndoBarView extends GLView {
27    private static final String TAG = "UndoBarView";
28
29    private static final int WHITE = 0xFFFFFFFF;
30    private static final int GRAY = 0xFFAAAAAA;
31
32    private final NinePatchTexture mPanel;
33    private final StringTexture mUndoText;
34    private final StringTexture mDeletedText;
35    private final ResourceTexture mUndoIcon;
36    private final int mBarHeight;
37    private final int mBarMargin;
38    private final int mUndoTextMargin;
39    private final int mIconSize;
40    private final int mIconMargin;
41    private final int mSeparatorTopMargin;
42    private final int mSeparatorBottomMargin;
43    private final int mSeparatorRightMargin;
44    private final int mSeparatorWidth;
45    private final int mDeletedTextMargin;
46    private final int mClickRegion;
47
48    private OnClickListener mOnClickListener;
49    private boolean mDownOnButton;
50
51    // This is the layout of UndoBarView. The unit is dp.
52    //
53    //    +-+----+----------------+-+--+----+-+------+--+-+
54    // 48 | |    | Deleted        | |  | <- | | UNDO |  | |
55    //    +-+----+----------------+-+--+----+-+------+--+-+
56    //     4  16                   1 12  32  8        16 4
57    public UndoBarView(Context context) {
58        mBarHeight = (int) GalleryUtils.dpToPixel(48);
59        mBarMargin = (int) GalleryUtils.dpToPixel(4);
60        mUndoTextMargin = (int) GalleryUtils.dpToPixel(16);
61        mIconMargin = (int) GalleryUtils.dpToPixel(8);
62        mIconSize = (int) GalleryUtils.dpToPixel(32);
63        mSeparatorRightMargin = (int) GalleryUtils.dpToPixel(12);
64        mSeparatorTopMargin = (int) GalleryUtils.dpToPixel(10);
65        mSeparatorBottomMargin = (int) GalleryUtils.dpToPixel(10);
66        mSeparatorWidth = (int) GalleryUtils.dpToPixel(1);
67        mDeletedTextMargin = (int) GalleryUtils.dpToPixel(16);
68
69        mPanel = new NinePatchTexture(context, R.drawable.panel_undo_holo);
70        mUndoText = StringTexture.newInstance(context.getString(R.string.undo),
71                GalleryUtils.dpToPixel(12), GRAY, 0, true);
72        mDeletedText = StringTexture.newInstance(
73                context.getString(R.string.deleted),
74                GalleryUtils.dpToPixel(16), WHITE);
75        mUndoIcon = new ResourceTexture(
76                context, R.drawable.ic_menu_revert_holo_dark);
77        mClickRegion = mBarMargin + mUndoTextMargin + mUndoText.getWidth()
78                + mIconMargin + mIconSize + mSeparatorRightMargin;
79    }
80
81    public void setOnClickListener(OnClickListener listener) {
82        mOnClickListener = listener;
83    }
84
85    @Override
86    protected void onMeasure(int widthSpec, int heightSpec) {
87        setMeasuredSize(0 /* unused */, mBarHeight);
88    }
89
90    @Override
91    protected void render(GLCanvas canvas) {
92        super.render(canvas);
93        advanceAnimation();
94
95        canvas.save(GLCanvas.SAVE_FLAG_ALPHA);
96        canvas.multiplyAlpha(mAlpha);
97
98        int w = getWidth();
99        int h = getHeight();
100        mPanel.draw(canvas, mBarMargin, 0, w - mBarMargin * 2, mBarHeight);
101
102        int x = w - mBarMargin;
103        int y;
104
105        x -= mUndoTextMargin + mUndoText.getWidth();
106        y = (mBarHeight - mUndoText.getHeight()) / 2;
107        mUndoText.draw(canvas, x, y);
108
109        x -= mIconMargin + mIconSize;
110        y = (mBarHeight - mIconSize) / 2;
111        mUndoIcon.draw(canvas, x, y, mIconSize, mIconSize);
112
113        x -= mSeparatorRightMargin + mSeparatorWidth;
114        y = mSeparatorTopMargin;
115        canvas.fillRect(x, y, mSeparatorWidth,
116                mBarHeight - mSeparatorTopMargin - mSeparatorBottomMargin, GRAY);
117
118        x = mBarMargin + mDeletedTextMargin;
119        y = (mBarHeight - mDeletedText.getHeight()) / 2;
120        mDeletedText.draw(canvas, x, y);
121
122        canvas.restore();
123    }
124
125    @Override
126    protected boolean onTouch(MotionEvent event) {
127        switch (event.getAction()) {
128            case MotionEvent.ACTION_DOWN:
129                mDownOnButton = inUndoButton(event);
130                break;
131            case MotionEvent.ACTION_UP:
132                if (mDownOnButton) {
133                    if (mOnClickListener != null && inUndoButton(event)) {
134                        mOnClickListener.onClick(this);
135                    }
136                    mDownOnButton = false;
137                }
138                break;
139            case MotionEvent.ACTION_CANCEL:
140                mDownOnButton = false;
141                break;
142        }
143        return true;
144    }
145
146    // Check if the event is on the right of the separator
147    private boolean inUndoButton(MotionEvent event) {
148        float x = event.getX();
149        float y = event.getY();
150        int w = getWidth();
151        int h = getHeight();
152        return (x >= w - mClickRegion && x < w && y >= 0 && y < h);
153    }
154
155    ////////////////////////////////////////////////////////////////////////////
156    //  Alpha Animation
157    ////////////////////////////////////////////////////////////////////////////
158
159    private static final long NO_ANIMATION = -1;
160    private static long ANIM_TIME = 200;
161    private long mAnimationStartTime = NO_ANIMATION;
162    private float mFromAlpha, mToAlpha;
163    private float mAlpha;
164
165    private static float getTargetAlpha(int visibility) {
166        return (visibility == VISIBLE) ? 1f : 0f;
167    }
168
169    public void setVisibility(int visibility) {
170        mAlpha = getTargetAlpha(visibility);
171        mAnimationStartTime = NO_ANIMATION;
172        super.setVisibility(visibility);
173        invalidate();
174    }
175
176    public void animateVisibility(int visibility) {
177        float target = getTargetAlpha(visibility);
178        if (mAnimationStartTime == NO_ANIMATION && mAlpha == target) return;
179        if (mAnimationStartTime != NO_ANIMATION && mToAlpha == target) return;
180
181        mFromAlpha = mAlpha;
182        mToAlpha = target;
183        mAnimationStartTime = AnimationTime.startTime();
184
185        super.setVisibility(VISIBLE);
186        invalidate();
187    }
188
189    private void advanceAnimation() {
190        if (mAnimationStartTime == NO_ANIMATION) return;
191
192        float delta = (float) (AnimationTime.get() - mAnimationStartTime) /
193                ANIM_TIME;
194        mAlpha = mFromAlpha + ((mToAlpha > mFromAlpha) ? delta : -delta);
195        mAlpha = Utils.clamp(mAlpha, 0f, 1f);
196
197        if (mAlpha == mToAlpha) {
198            mAnimationStartTime = NO_ANIMATION;
199            if (mAlpha == 0) {
200                super.setVisibility(INVISIBLE);
201            }
202        }
203        invalidate();
204    }
205}
206