RotateDrawable.java revision b798689749c64baba81f02e10cf2157c747d6b46 
1/*
2 * Copyright (C) 2007 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.graphics.Canvas;
23import android.graphics.ColorFilter;
24import android.graphics.Rect;
25import android.content.res.Resources;
26import android.content.res.TypedArray;
27import android.util.TypedValue;
28import android.util.AttributeSet;
29import android.util.Log;
30
31import java.io.IOException;
32
33/**
34 * <p>A Drawable that can rotate another Drawable based on the current level
35 * value. The start and end angles of rotation can be controlled to map any
36 * circular arc to the level values range.</p>
37 *
38 * <p>It can be defined in an XML file with the <code>&lt;rotate></code> element.</p>
39 *
40 * @attr ref android.R.styleable#RotateDrawable_visible
41 * @attr ref android.R.styleable#RotateDrawable_fromDegrees
42 * @attr ref android.R.styleable#RotateDrawable_toDegrees
43 * @attr ref android.R.styleable#RotateDrawable_pivotX
44 * @attr ref android.R.styleable#RotateDrawable_pivotY
45 * @attr ref android.R.styleable#RotateDrawable_drawable
46 */
47public class RotateDrawable extends Drawable implements Drawable.Callback {
48
49    /**
50     * <p>Create a new rotating drawable with an empty state.</p>
51     */
52    public RotateDrawable() {
53        this(null);
54    }
55
56    /**
57     * <p>Create a new rotating drawable with the specified state. A copy of
58     * this state is used as the internal state for the newly created
59     * drawable.</p>
60     *
61     * @param rotateState the state for this drawable
62     */
63    private RotateDrawable(RotateState rotateState) {
64        mState = new RotateState(rotateState, this);
65    }
66
67    public void draw(Canvas canvas) {
68        int saveCount = canvas.save();
69
70        Rect bounds = mState.mDrawable.getBounds();
71
72        int w = bounds.right - bounds.left;
73        int h = bounds.bottom - bounds.top;
74
75        final RotateState st = mState;
76
77        float px = st.mPivotXRel ? (w * st.mPivotX) : st.mPivotX;
78        float py = st.mPivotYRel ? (h * st.mPivotY) : st.mPivotY;
79
80        canvas.rotate(st.mCurrentDegrees, px, py);
81
82        st.mDrawable.draw(canvas);
83
84        canvas.restoreToCount(saveCount);
85    }
86
87    @Override
88    public int getChangingConfigurations() {
89        return super.getChangingConfigurations()
90                | mState.mChangingConfigurations
91                | mState.mDrawable.getChangingConfigurations();
92    }
93
94    public void setAlpha(int alpha) {
95        mState.mDrawable.setAlpha(alpha);
96    }
97
98    public void setColorFilter(ColorFilter cf) {
99        mState.mDrawable.setColorFilter(cf);
100    }
101
102    public int getOpacity() {
103        return mState.mDrawable.getOpacity();
104    }
105
106    public void invalidateDrawable(Drawable who) {
107        if (mCallback != null) {
108            mCallback.invalidateDrawable(this);
109        }
110    }
111
112    public void scheduleDrawable(Drawable who, Runnable what, long when) {
113        if (mCallback != null) {
114            mCallback.scheduleDrawable(this, what, when);
115        }
116    }
117
118    public void unscheduleDrawable(Drawable who, Runnable what) {
119        if (mCallback != null) {
120            mCallback.unscheduleDrawable(this, what);
121        }
122    }
123
124   @Override
125    public boolean getPadding(Rect padding) {
126        return mState.mDrawable.getPadding(padding);
127    }
128
129    @Override
130    public boolean setVisible(boolean visible, boolean restart) {
131        mState.mDrawable.setVisible(visible, restart);
132        return super.setVisible(visible, restart);
133    }
134
135    @Override
136    public boolean isStateful() {
137        return mState.mDrawable.isStateful();
138    }
139
140    @Override
141    protected boolean onStateChange(int[] state) {
142        boolean changed = mState.mDrawable.setState(state);
143        onBoundsChange(getBounds());
144        return changed;
145    }
146
147    @Override
148    protected boolean onLevelChange(int level) {
149        mState.mDrawable.setLevel(level);
150        onBoundsChange(getBounds());
151
152        mState.mCurrentDegrees = mState.mFromDegrees +
153                (mState.mToDegrees - mState.mFromDegrees) *
154                        ((float) level / MAX_LEVEL);
155
156        invalidateSelf();
157        return true;
158    }
159
160    @Override
161    protected void onBoundsChange(Rect bounds) {
162        mState.mDrawable.setBounds(bounds.left, bounds.top,
163                bounds.right, bounds.bottom);
164    }
165
166    @Override
167    public int getIntrinsicWidth() {
168        return mState.mDrawable.getIntrinsicWidth();
169    }
170
171    @Override
172    public int getIntrinsicHeight() {
173        return mState.mDrawable.getIntrinsicHeight();
174    }
175
176    @Override
177    public ConstantState getConstantState() {
178        if (mState.canConstantState()) {
179            mState.mChangingConfigurations = super.getChangingConfigurations();
180            return mState;
181        }
182        return null;
183    }
184
185    @Override
186    public void inflate(Resources r, XmlPullParser parser, AttributeSet attrs)
187            throws XmlPullParserException, IOException {
188
189        TypedArray a = r.obtainAttributes(attrs,
190                com.android.internal.R.styleable.RotateDrawable);
191
192        super.inflateWithAttributes(r, parser, a,
193                com.android.internal.R.styleable.RotateDrawable_visible);
194
195        TypedValue tv = a.peekValue(com.android.internal.R.styleable.RotateDrawable_pivotX);
196        boolean pivotXRel = tv.type == TypedValue.TYPE_FRACTION;
197        float pivotX = pivotXRel ? tv.getFraction(1.0f, 1.0f) : tv.getFloat();
198
199        tv = a.peekValue(com.android.internal.R.styleable.RotateDrawable_pivotY);
200        boolean pivotYRel = tv.type == TypedValue.TYPE_FRACTION;
201        float pivotY = pivotYRel ? tv.getFraction(1.0f, 1.0f) : tv.getFloat();
202
203        float fromDegrees = a.getFloat(
204                com.android.internal.R.styleable.RotateDrawable_fromDegrees, 0.0f);
205        float toDegrees = a.getFloat(
206                com.android.internal.R.styleable.RotateDrawable_toDegrees, 360.0f);
207
208        toDegrees = Math.max(fromDegrees, toDegrees);
209
210        int res = a.getResourceId(
211                com.android.internal.R.styleable.RotateDrawable_drawable, 0);
212        Drawable drawable = null;
213        if (res > 0) {
214            drawable = r.getDrawable(res);
215        }
216
217        a.recycle();
218
219        int outerDepth = parser.getDepth();
220        int type;
221        while ((type = parser.next()) != XmlPullParser.END_DOCUMENT &&
222               (type != XmlPullParser.END_TAG || parser.getDepth() > outerDepth)) {
223
224            if (type != XmlPullParser.START_TAG) {
225                continue;
226            }
227
228            if ((drawable = Drawable.createFromXmlInner(r, parser, attrs)) == null) {
229                Log.w("drawable", "Bad element under <rotate>: "
230                        + parser .getName());
231            }
232        }
233
234        if (drawable == null) {
235            Log.w("drawable", "No drawable specified for <rotate>");
236        }
237
238        mState.mDrawable = drawable;
239        mState.mPivotXRel = pivotXRel;
240        mState.mPivotX = pivotX;
241        mState.mPivotYRel = pivotYRel;
242        mState.mPivotY = pivotY;
243        mState.mFromDegrees = mState.mCurrentDegrees = fromDegrees;
244        mState.mToDegrees = toDegrees;
245
246        if (drawable != null) {
247            drawable.setCallback(this);
248        }
249    }
250
251    /**
252     * <p>Represents the state of a rotation for a given drawable. The same
253     * rotate drawable can be invoked with different states to drive several
254     * rotations at the same time.</p>
255     */
256    final static class RotateState extends Drawable.ConstantState {
257        Drawable mDrawable;
258
259        int mChangingConfigurations;
260
261        boolean mPivotXRel;
262        float mPivotX;
263        boolean mPivotYRel;
264        float mPivotY;
265
266        float mFromDegrees;
267        float mToDegrees;
268
269        float mCurrentDegrees;
270
271        public RotateState(RotateState source, RotateDrawable owner) {
272            if (source != null) {
273                mDrawable = source.mDrawable.getConstantState().newDrawable();
274                mDrawable.setCallback(owner);
275                mPivotXRel = source.mPivotXRel;
276                mPivotX = source.mPivotX;
277                mPivotYRel = source.mPivotYRel;
278                mPivotY = source.mPivotY;
279                mFromDegrees = mCurrentDegrees = source.mFromDegrees;
280                mToDegrees = source.mToDegrees;
281                mCanConstantState = mCheckedConstantState = true;
282            }
283        }
284
285        @Override
286        public Drawable newDrawable() {
287            return new RotateDrawable(this);
288        }
289
290        @Override
291        public int getChangingConfigurations() {
292            return mChangingConfigurations;
293        }
294
295        public boolean canConstantState() {
296            if (!mCheckedConstantState) {
297                mCanConstantState = mDrawable.getConstantState() != null;
298                mCheckedConstantState = true;
299            }
300
301            return mCanConstantState;
302        }
303
304        private boolean mCanConstantState;
305        private boolean mCheckedConstantState;
306    }
307
308    private static final float MAX_LEVEL = 10000.0f;
309
310    private RotateState mState;
311}
312