ClipDrawable.java revision cda212d79d449468384cc7744878b8c99984059c 
1/*
2 * Copyright (C) 2006 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 android.graphics.drawable;
18
19import org.xmlpull.v1.XmlPullParser;
20import org.xmlpull.v1.XmlPullParserException;
21
22import android.content.res.Resources;
23import android.content.res.TypedArray;
24import android.content.res.Resources.Theme;
25import android.graphics.*;
26import android.view.Gravity;
27import android.util.AttributeSet;
28
29import java.io.IOException;
30
31/**
32 * A Drawable that clips another Drawable based on this Drawable's current
33 * level value.  You can control how much the child Drawable gets clipped in width
34 * and height based on the level, as well as a gravity to control where it is
35 * placed in its overall container.  Most often used to implement things like
36 * progress bars, by increasing the drawable's level with {@link
37 * android.graphics.drawable.Drawable#setLevel(int) setLevel()}.
38 * <p class="note"><strong>Note:</strong> The drawable is clipped completely and not visible when
39 * the level is 0 and fully revealed when the level is 10,000.</p>
40 *
41 * <p>It can be defined in an XML file with the <code>&lt;clip></code> element.  For more
42 * information, see the guide to <a
43 * href="{@docRoot}guide/topics/resources/drawable-resource.html">Drawable Resources</a>.</p>
44 *
45 * @attr ref android.R.styleable#ClipDrawable_clipOrientation
46 * @attr ref android.R.styleable#ClipDrawable_gravity
47 * @attr ref android.R.styleable#ClipDrawable_drawable
48 */
49public class ClipDrawable extends Drawable implements Drawable.Callback {
50    private ClipState mClipState;
51    private final Rect mTmpRect = new Rect();
52
53    public static final int HORIZONTAL = 1;
54    public static final int VERTICAL = 2;
55
56    ClipDrawable() {
57        this(null, null);
58    }
59
60    /**
61     * @param orientation Bitwise-or of {@link #HORIZONTAL} and/or {@link #VERTICAL}
62     */
63    public ClipDrawable(Drawable drawable, int gravity, int orientation) {
64        this(null, null);
65
66        mClipState.mDrawable = drawable;
67        mClipState.mGravity = gravity;
68        mClipState.mOrientation = orientation;
69
70        if (drawable != null) {
71            drawable.setCallback(this);
72        }
73    }
74
75    @Override
76    public void inflate(Resources r, XmlPullParser parser, AttributeSet attrs, Theme theme)
77            throws XmlPullParserException, IOException {
78        super.inflate(r, parser, attrs, theme);
79
80        int type;
81
82        TypedArray a = r.obtainAttributes(attrs, com.android.internal.R.styleable.ClipDrawable);
83
84        int orientation = a.getInt(
85                com.android.internal.R.styleable.ClipDrawable_clipOrientation,
86                HORIZONTAL);
87        int g = a.getInt(com.android.internal.R.styleable.ClipDrawable_gravity, Gravity.LEFT);
88        Drawable dr = a.getDrawable(com.android.internal.R.styleable.ClipDrawable_drawable);
89
90        a.recycle();
91
92        final int outerDepth = parser.getDepth();
93        while ((type = parser.next()) != XmlPullParser.END_DOCUMENT
94                && (type != XmlPullParser.END_TAG || parser.getDepth() > outerDepth)) {
95            if (type != XmlPullParser.START_TAG) {
96                continue;
97            }
98            dr = Drawable.createFromXmlInner(r, parser, attrs, theme);
99        }
100
101        if (dr == null) {
102            throw new IllegalArgumentException("No drawable specified for <clip>");
103        }
104
105        mClipState.mDrawable = dr;
106        mClipState.mOrientation = orientation;
107        mClipState.mGravity = g;
108
109        dr.setCallback(this);
110    }
111
112    // overrides from Drawable.Callback
113
114    public void invalidateDrawable(Drawable who) {
115        final Callback callback = getCallback();
116        if (callback != null) {
117            callback.invalidateDrawable(this);
118        }
119    }
120
121    public void scheduleDrawable(Drawable who, Runnable what, long when) {
122        final Callback callback = getCallback();
123        if (callback != null) {
124            callback.scheduleDrawable(this, what, when);
125        }
126    }
127
128    public void unscheduleDrawable(Drawable who, Runnable what) {
129        final Callback callback = getCallback();
130        if (callback != null) {
131            callback.unscheduleDrawable(this, what);
132        }
133    }
134
135    // overrides from Drawable
136
137    @Override
138    public int getChangingConfigurations() {
139        return super.getChangingConfigurations()
140                | mClipState.mChangingConfigurations
141                | mClipState.mDrawable.getChangingConfigurations();
142    }
143
144    @Override
145    public boolean getPadding(Rect padding) {
146        // XXX need to adjust padding!
147        return mClipState.mDrawable.getPadding(padding);
148    }
149
150    @Override
151    public boolean setVisible(boolean visible, boolean restart) {
152        mClipState.mDrawable.setVisible(visible, restart);
153        return super.setVisible(visible, restart);
154    }
155
156    @Override
157    public void setAlpha(int alpha) {
158        mClipState.mDrawable.setAlpha(alpha);
159    }
160
161    @Override
162    public int getAlpha() {
163        return mClipState.mDrawable.getAlpha();
164    }
165
166    @Override
167    public void setColorFilter(ColorFilter cf) {
168        mClipState.mDrawable.setColorFilter(cf);
169    }
170
171    @Override
172    public int getOpacity() {
173        return mClipState.mDrawable.getOpacity();
174    }
175
176    @Override
177    public boolean isStateful() {
178        return mClipState.mDrawable.isStateful();
179    }
180
181    @Override
182    protected boolean onStateChange(int[] state) {
183        return mClipState.mDrawable.setState(state);
184    }
185
186    @Override
187    protected boolean onLevelChange(int level) {
188        mClipState.mDrawable.setLevel(level);
189        invalidateSelf();
190        return true;
191    }
192
193    @Override
194    protected void onBoundsChange(Rect bounds) {
195        mClipState.mDrawable.setBounds(bounds);
196    }
197
198    @Override
199    public void draw(Canvas canvas) {
200
201        if (mClipState.mDrawable.getLevel() == 0) {
202            return;
203        }
204
205        final Rect r = mTmpRect;
206        final Rect bounds = getBounds();
207        int level = getLevel();
208        int w = bounds.width();
209        final int iw = 0; //mClipState.mDrawable.getIntrinsicWidth();
210        if ((mClipState.mOrientation & HORIZONTAL) != 0) {
211            w -= (w - iw) * (10000 - level) / 10000;
212        }
213        int h = bounds.height();
214        final int ih = 0; //mClipState.mDrawable.getIntrinsicHeight();
215        if ((mClipState.mOrientation & VERTICAL) != 0) {
216            h -= (h - ih) * (10000 - level) / 10000;
217        }
218        final int layoutDirection = getLayoutDirection();
219        Gravity.apply(mClipState.mGravity, w, h, bounds, r, layoutDirection);
220
221        if (w > 0 && h > 0) {
222            canvas.save();
223            canvas.clipRect(r);
224            mClipState.mDrawable.draw(canvas);
225            canvas.restore();
226        }
227    }
228
229    @Override
230    public int getIntrinsicWidth() {
231        return mClipState.mDrawable.getIntrinsicWidth();
232    }
233
234    @Override
235    public int getIntrinsicHeight() {
236        return mClipState.mDrawable.getIntrinsicHeight();
237    }
238
239    @Override
240    public ConstantState getConstantState() {
241        if (mClipState.canConstantState()) {
242            mClipState.mChangingConfigurations = getChangingConfigurations();
243            return mClipState;
244        }
245        return null;
246    }
247
248    /** @hide */
249    @Override
250    public void setLayoutDirection(int layoutDirection) {
251        mClipState.mDrawable.setLayoutDirection(layoutDirection);
252        super.setLayoutDirection(layoutDirection);
253    }
254
255    final static class ClipState extends ConstantState {
256        Drawable mDrawable;
257        int mChangingConfigurations;
258        int mOrientation;
259        int mGravity;
260
261        private boolean mCheckedConstantState;
262        private boolean mCanConstantState;
263
264        ClipState(ClipState orig, ClipDrawable owner, Resources res) {
265            if (orig != null) {
266                if (res != null) {
267                    mDrawable = orig.mDrawable.getConstantState().newDrawable(res);
268                } else {
269                    mDrawable = orig.mDrawable.getConstantState().newDrawable();
270                }
271                mDrawable.setCallback(owner);
272                mDrawable.setLayoutDirection(orig.mDrawable.getLayoutDirection());
273                mOrientation = orig.mOrientation;
274                mGravity = orig.mGravity;
275                mCheckedConstantState = mCanConstantState = true;
276            }
277        }
278
279        @Override
280        public Drawable newDrawable() {
281            return new ClipDrawable(this, null);
282        }
283
284        @Override
285        public Drawable newDrawable(Resources res) {
286            return new ClipDrawable(this, res);
287        }
288
289        @Override
290        public int getChangingConfigurations() {
291            return mChangingConfigurations;
292        }
293
294        boolean canConstantState() {
295            if (!mCheckedConstantState) {
296                mCanConstantState = mDrawable.getConstantState() != null;
297                mCheckedConstantState = true;
298            }
299
300            return mCanConstantState;
301        }
302    }
303
304    private ClipDrawable(ClipState state, Resources res) {
305        mClipState = new ClipState(state, this, res);
306    }
307}
308
309