BubbleTextView.java revision d69e11384c9eefe49039b198edcece5d59c8868f 
1/*
2 * Copyright (C) 2008 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.launcher2;
18
19import com.android.launcher.R;
20
21import android.content.Context;
22import android.content.res.Resources;
23import android.graphics.Bitmap;
24import android.graphics.Canvas;
25import android.graphics.Color;
26import android.graphics.Paint;
27import android.graphics.Rect;
28import android.graphics.Region;
29import android.graphics.Region.Op;
30import android.graphics.drawable.Drawable;
31import android.util.AttributeSet;
32import android.view.MotionEvent;
33import android.view.View;
34import android.widget.TextView;
35
36/**
37 * TextView that draws a bubble behind the text. We cannot use a LineBackgroundSpan
38 * because we want to make the bubble taller than the text and TextView's clip is
39 * too aggressive.
40 */
41public class BubbleTextView extends TextView implements VisibilityChangedBroadcaster {
42    static final float CORNER_RADIUS = 4.0f;
43    static final float SHADOW_LARGE_RADIUS = 4.0f;
44    static final float SHADOW_SMALL_RADIUS = 1.75f;
45    static final float SHADOW_Y_OFFSET = 2.0f;
46    static final int SHADOW_LARGE_COLOUR = 0xCC000000;
47    static final int SHADOW_SMALL_COLOUR = 0xBB000000;
48    static final float PADDING_H = 8.0f;
49    static final float PADDING_V = 3.0f;
50
51    private Paint mPaint;
52    private float mBubbleColorAlpha;
53    private int mPrevAlpha = -1;
54
55    private final HolographicOutlineHelper mOutlineHelper = new HolographicOutlineHelper();
56    private final Canvas mTempCanvas = new Canvas();
57    private final Rect mTempRect = new Rect();
58    private final Paint mTempPaint = new Paint();
59    private boolean mDidInvalidateForPressedState;
60    private Bitmap mPressedOrFocusedBackground;
61    private int mFocusedOutlineColor;
62    private int mFocusedGlowColor;
63    private int mPressedOutlineColor;
64    private int mPressedGlowColor;
65
66    private boolean mBackgroundSizeChanged;
67    private Drawable mBackground;
68
69    private boolean mStayPressed;
70
71    private VisibilityChangedListener mOnVisibilityChangedListener;
72
73    public BubbleTextView(Context context) {
74        super(context);
75        init();
76    }
77
78    public BubbleTextView(Context context, AttributeSet attrs) {
79        super(context, attrs);
80        init();
81    }
82
83    public BubbleTextView(Context context, AttributeSet attrs, int defStyle) {
84        super(context, attrs, defStyle);
85        init();
86    }
87
88    private void init() {
89        mBackground = getBackground();
90        setFocusable(true);
91        setBackgroundDrawable(null);
92
93        final Resources res = getContext().getResources();
94        int bubbleColor = res.getColor(R.color.bubble_dark_background);
95        mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
96        mPaint.setColor(bubbleColor);
97        mBubbleColorAlpha = Color.alpha(bubbleColor) / 255.0f;
98        mFocusedOutlineColor = res.getColor(R.color.workspace_item_focused_outline_color);
99        mFocusedGlowColor = res.getColor(R.color.workspace_item_focused_glow_color);
100        mPressedOutlineColor = res.getColor(R.color.workspace_item_pressed_outline_color);
101        mPressedGlowColor = res.getColor(R.color.workspace_item_pressed_glow_color);
102
103        setShadowLayer(SHADOW_LARGE_RADIUS, 0.0f, SHADOW_Y_OFFSET, SHADOW_LARGE_COLOUR);
104    }
105
106    public void applyFromShortcutInfo(ShortcutInfo info, IconCache iconCache) {
107        Bitmap b = info.getIcon(iconCache);
108
109        setCompoundDrawablesWithIntrinsicBounds(null,
110                new FastBitmapDrawable(b),
111                null, null);
112        setText(info.title);
113        setTag(info);
114    }
115
116    @Override
117    protected boolean setFrame(int left, int top, int right, int bottom) {
118        if (mLeft != left || mRight != right || mTop != top || mBottom != bottom) {
119            mBackgroundSizeChanged = true;
120        }
121        return super.setFrame(left, top, right, bottom);
122    }
123
124    @Override
125    protected boolean verifyDrawable(Drawable who) {
126        return who == mBackground || super.verifyDrawable(who);
127    }
128
129    @Override
130    protected void drawableStateChanged() {
131        if (isPressed()) {
132            // In this case, we have already created the pressed outline on ACTION_DOWN,
133            // so we just need to do an invalidate to trigger draw
134            if (!mDidInvalidateForPressedState) {
135                setCellLayoutPressedOrFocusedIcon();
136            }
137        } else {
138            // Otherwise, either clear the pressed/focused background, or create a background
139            // for the focused state
140            final boolean backgroundEmptyBefore = mPressedOrFocusedBackground == null;
141            if (!mStayPressed) {
142                mPressedOrFocusedBackground = null;
143            }
144            if (isFocused()) {
145                if (mLayout == null) {
146                    // In some cases, we get focus before we have been layed out. Set the
147                    // background to null so that it will get created when the view is drawn.
148                    mPressedOrFocusedBackground = null;
149                } else {
150                    mPressedOrFocusedBackground = createGlowingOutline(
151                            mTempCanvas, mFocusedGlowColor, mFocusedOutlineColor);
152                }
153                mStayPressed = false;
154                setCellLayoutPressedOrFocusedIcon();
155            }
156            final boolean backgroundEmptyNow = mPressedOrFocusedBackground == null;
157            if (!backgroundEmptyBefore && backgroundEmptyNow) {
158                setCellLayoutPressedOrFocusedIcon();
159            }
160        }
161
162        Drawable d = mBackground;
163        if (d != null && d.isStateful()) {
164            d.setState(getDrawableState());
165        }
166        super.drawableStateChanged();
167    }
168
169    /**
170     * Draw this BubbleTextView into the given Canvas.
171     *
172     * @param destCanvas the canvas to draw on
173     * @param padding the horizontal and vertical padding to use when drawing
174     */
175    private void drawWithPadding(Canvas destCanvas, int padding) {
176        final Rect clipRect = mTempRect;
177        getDrawingRect(clipRect);
178
179        // adjust the clip rect so that we don't include the text label
180        clipRect.bottom =
181            getExtendedPaddingTop() - (int) BubbleTextView.PADDING_V + getLayout().getLineTop(0);
182
183        // Draw the View into the bitmap.
184        // The translate of scrollX and scrollY is necessary when drawing TextViews, because
185        // they set scrollX and scrollY to large values to achieve centered text
186        destCanvas.save();
187        destCanvas.translate(-getScrollX() + padding / 2, -getScrollY() + padding / 2);
188        destCanvas.clipRect(clipRect, Op.REPLACE);
189        draw(destCanvas);
190        destCanvas.restore();
191    }
192
193    /**
194     * Returns a new bitmap to be used as the object outline, e.g. to visualize the drop location.
195     * Responsibility for the bitmap is transferred to the caller.
196     */
197    private Bitmap createGlowingOutline(Canvas canvas, int outlineColor, int glowColor) {
198        final int padding = HolographicOutlineHelper.MAX_OUTER_BLUR_RADIUS;
199        final Bitmap b = Bitmap.createBitmap(
200                getWidth() + padding, getHeight() + padding, Bitmap.Config.ARGB_8888);
201
202        canvas.setBitmap(b);
203        drawWithPadding(canvas, padding);
204        mOutlineHelper.applyExtraThickExpensiveOutlineWithBlur(b, canvas, glowColor, outlineColor);
205
206        return b;
207    }
208
209    @Override
210    public boolean onTouchEvent(MotionEvent event) {
211        // Call the superclass onTouchEvent first, because sometimes it changes the state to
212        // isPressed() on an ACTION_UP
213        boolean result = super.onTouchEvent(event);
214
215        switch (event.getAction()) {
216            case MotionEvent.ACTION_DOWN:
217                // So that the pressed outline is visible immediately when isPressed() is true,
218                // we pre-create it on ACTION_DOWN (it takes a small but perceptible amount of time
219                // to create it)
220                if (mPressedOrFocusedBackground == null) {
221                    mPressedOrFocusedBackground = createGlowingOutline(
222                            mTempCanvas, mPressedGlowColor, mPressedOutlineColor);
223                }
224                // Invalidate so the pressed state is visible, or set a flag so we know that we
225                // have to call invalidate as soon as the state is "pressed"
226                if (isPressed()) {
227                    mDidInvalidateForPressedState = true;
228                    invalidate();
229                } else {
230                    mDidInvalidateForPressedState = false;
231                }
232                break;
233            case MotionEvent.ACTION_CANCEL:
234            case MotionEvent.ACTION_UP:
235                // If we've touched down and up on an item, and it's still not "pressed", then
236                // destroy the pressed outline
237                if (!isPressed()) {
238                    mPressedOrFocusedBackground = null;
239                }
240                break;
241        }
242        return result;
243    }
244
245    public void setVisibilityChangedListener(VisibilityChangedListener listener) {
246        mOnVisibilityChangedListener = listener;
247    }
248
249    @Override
250    protected void onVisibilityChanged(View changedView, int visibility) {
251        if (mOnVisibilityChangedListener != null) {
252            mOnVisibilityChangedListener.receiveVisibilityChangedMessage(this);
253        }
254        super.onVisibilityChanged(changedView, visibility);
255    }
256
257    void setStayPressed(boolean stayPressed) {
258        mStayPressed = stayPressed;
259        if (!stayPressed) {
260            mPressedOrFocusedBackground = null;
261        }
262        setCellLayoutPressedOrFocusedIcon();
263    }
264
265    void setCellLayoutPressedOrFocusedIcon() {
266        CellLayoutChildren parent = (CellLayoutChildren) getParent();
267        if (parent != null) {
268            CellLayout layout = (CellLayout) parent.getParent();
269            layout.setPressedOrFocusedIcon((mPressedOrFocusedBackground != null) ? this : null);
270        }
271    }
272
273    Bitmap getPressedOrFocusedBackground() {
274        return mPressedOrFocusedBackground;
275    }
276
277    int getPressedOrFocusedBackgroundPadding() {
278        return HolographicOutlineHelper.MAX_OUTER_BLUR_RADIUS / 2;
279    }
280
281    @Override
282    public void draw(Canvas canvas) {
283        final Drawable background = mBackground;
284        if (background != null) {
285            final int scrollX = mScrollX;
286            final int scrollY = mScrollY;
287
288            if (mBackgroundSizeChanged) {
289                background.setBounds(0, 0,  mRight - mLeft, mBottom - mTop);
290                mBackgroundSizeChanged = false;
291            }
292
293            if ((scrollX | scrollY) == 0) {
294                background.draw(canvas);
295            } else {
296                canvas.translate(scrollX, scrollY);
297                background.draw(canvas);
298                canvas.translate(-scrollX, -scrollY);
299            }
300        }
301        // We enhance the shadow by drawing the shadow twice
302        getPaint().setShadowLayer(SHADOW_LARGE_RADIUS, 0.0f, SHADOW_Y_OFFSET, SHADOW_LARGE_COLOUR);
303        super.draw(canvas);
304        canvas.save(Canvas.CLIP_SAVE_FLAG);
305        canvas.clipRect(mScrollX, mScrollY + getExtendedPaddingTop(), mScrollX + getWidth(),
306                mScrollY + getHeight(), Region.Op.INTERSECT);
307        getPaint().setShadowLayer(SHADOW_SMALL_RADIUS, 0.0f, 0.0f, SHADOW_SMALL_COLOUR);
308        super.draw(canvas);
309        canvas.restore();
310    }
311
312    @Override
313    protected void onAttachedToWindow() {
314        super.onAttachedToWindow();
315        if (mBackground != null) mBackground.setCallback(this);
316    }
317
318    @Override
319    protected void onDetachedFromWindow() {
320        super.onDetachedFromWindow();
321        if (mBackground != null) mBackground.setCallback(null);
322    }
323
324    @Override
325    protected boolean onSetAlpha(int alpha) {
326        if (mPrevAlpha != alpha) {
327            mPrevAlpha = alpha;
328            mPaint.setAlpha((int) (alpha * mBubbleColorAlpha));
329            super.onSetAlpha(alpha);
330        }
331        return true;
332    }
333}
334