1 /*
2  * Copyright (C) 2010 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 
17 package android.graphics;
18 
19 import com.android.ide.common.rendering.api.LayoutLog;
20 import com.android.layoutlib.bridge.Bridge;
21 import com.android.layoutlib.bridge.impl.DelegateManager;
22 import com.android.tools.layoutlib.annotations.LayoutlibDelegate;
23 
24 import android.graphics.Shader.TileMode;
25 
26 import java.awt.image.ColorModel;
27 import java.awt.image.DataBufferInt;
28 import java.awt.image.Raster;
29 import java.awt.image.SampleModel;
30 
31 /**
32  * Delegate implementing the native methods of android.graphics.RadialGradient
33  *
34  * Through the layoutlib_create tool, the original native methods of RadialGradient have been
35  * replaced by calls to methods of the same name in this delegate class.
36  *
37  * This class behaves like the original native implementation, but in Java, keeping previously
38  * native data into its own objects and mapping them to int that are sent back and forth between
39  * it and the original RadialGradient class.
40  *
41  * Because this extends {@link Shader_Delegate}, there's no need to use a {@link DelegateManager},
42  * as all the Shader classes will be added to the manager owned by {@link Shader_Delegate}.
43  *
44  * @see Shader_Delegate
45  *
46  */
47 public class RadialGradient_Delegate extends Gradient_Delegate {
48 
49     // ---- delegate data ----
50     private java.awt.Paint mJavaPaint;
51 
52     // ---- Public Helper methods ----
53 
54     @Override
getJavaPaint()55     public java.awt.Paint getJavaPaint() {
56         return mJavaPaint;
57     }
58 
59     // ---- native methods ----
60 
61     @LayoutlibDelegate
nativeCreate1(long matrix, float x, float y, float radius, int colors[], float positions[], int tileMode)62     /*package*/ static long nativeCreate1(long matrix, float x, float y, float radius,
63             int colors[], float positions[], int tileMode) {
64         RadialGradient_Delegate newDelegate = new RadialGradient_Delegate(matrix, x, y, radius,
65                 colors, positions, Shader_Delegate.getTileMode(tileMode));
66         return sManager.addNewDelegate(newDelegate);
67     }
68 
69     @LayoutlibDelegate
nativeCreate2(long matrix, float x, float y, float radius, int color0, int color1, int tileMode)70     /*package*/ static long nativeCreate2(long matrix, float x, float y, float radius,
71             int color0, int color1, int tileMode) {
72         return nativeCreate1(matrix, x, y, radius, new int[] { color0, color1 },
73                 null /*positions*/, tileMode);
74     }
75 
76     // ---- Private delegate/helper methods ----
77 
78     /**
79      * Create a shader that draws a radial gradient given the center and radius.
80      *
81      * @param nativeMatrix reference to the shader's native transformation matrix
82      * @param x The x-coordinate of the center of the radius
83      * @param y The y-coordinate of the center of the radius
84      * @param radius Must be positive. The radius of the circle for this
85      *            gradient
86      * @param colors The colors to be distributed between the center and edge of
87      *            the circle
88      * @param positions May be NULL. The relative position of each corresponding
89      *            color in the colors array. If this is NULL, the the colors are
90      *            distributed evenly between the center and edge of the circle.
91      * @param tile The Shader tiling mode
92      */
RadialGradient_Delegate(long nativeMatrix, float x, float y, float radius, int colors[], float positions[], TileMode tile)93     private RadialGradient_Delegate(long nativeMatrix, float x, float y, float radius,
94             int colors[], float positions[], TileMode tile) {
95         super(nativeMatrix, colors, positions);
96         mJavaPaint = new RadialGradientPaint(x, y, radius, mColors, mPositions, tile);
97     }
98 
99     private class RadialGradientPaint extends GradientPaint {
100 
101         private final float mX;
102         private final float mY;
103         private final float mRadius;
104 
RadialGradientPaint(float x, float y, float radius, int[] colors, float[] positions, TileMode mode)105         public RadialGradientPaint(float x, float y, float radius,
106                 int[] colors, float[] positions, TileMode mode) {
107             super(colors, positions, mode);
108             mX = x;
109             mY = y;
110             mRadius = radius;
111         }
112 
113         @Override
createContext( java.awt.image.ColorModel colorModel, java.awt.Rectangle deviceBounds, java.awt.geom.Rectangle2D userBounds, java.awt.geom.AffineTransform xform, java.awt.RenderingHints hints)114         public java.awt.PaintContext createContext(
115                 java.awt.image.ColorModel     colorModel,
116                 java.awt.Rectangle            deviceBounds,
117                 java.awt.geom.Rectangle2D     userBounds,
118                 java.awt.geom.AffineTransform xform,
119                 java.awt.RenderingHints       hints) {
120             precomputeGradientColors();
121 
122             java.awt.geom.AffineTransform canvasMatrix;
123             try {
124                 canvasMatrix = xform.createInverse();
125             } catch (java.awt.geom.NoninvertibleTransformException e) {
126                 Bridge.getLog().fidelityWarning(LayoutLog.TAG_MATRIX_INVERSE,
127                         "Unable to inverse matrix in RadialGradient", e, null /*data*/);
128                 canvasMatrix = new java.awt.geom.AffineTransform();
129             }
130 
131             java.awt.geom.AffineTransform localMatrix = getLocalMatrix();
132             try {
133                 localMatrix = localMatrix.createInverse();
134             } catch (java.awt.geom.NoninvertibleTransformException e) {
135                 Bridge.getLog().fidelityWarning(LayoutLog.TAG_MATRIX_INVERSE,
136                         "Unable to inverse matrix in RadialGradient", e, null /*data*/);
137                 localMatrix = new java.awt.geom.AffineTransform();
138             }
139 
140             return new RadialGradientPaintContext(canvasMatrix, localMatrix, colorModel);
141         }
142 
143         private class RadialGradientPaintContext implements java.awt.PaintContext {
144 
145             private final java.awt.geom.AffineTransform mCanvasMatrix;
146             private final java.awt.geom.AffineTransform mLocalMatrix;
147             private final java.awt.image.ColorModel mColorModel;
148 
RadialGradientPaintContext( java.awt.geom.AffineTransform canvasMatrix, java.awt.geom.AffineTransform localMatrix, java.awt.image.ColorModel colorModel)149             public RadialGradientPaintContext(
150                     java.awt.geom.AffineTransform canvasMatrix,
151                     java.awt.geom.AffineTransform localMatrix,
152                     java.awt.image.ColorModel colorModel) {
153                 mCanvasMatrix = canvasMatrix;
154                 mLocalMatrix = localMatrix;
155                 mColorModel = colorModel.hasAlpha() ? colorModel : ColorModel.getRGBdefault();
156             }
157 
158             @Override
dispose()159             public void dispose() {
160             }
161 
162             @Override
getColorModel()163             public java.awt.image.ColorModel getColorModel() {
164                 return mColorModel;
165             }
166 
167             @Override
getRaster(int x, int y, int w, int h)168             public java.awt.image.Raster getRaster(int x, int y, int w, int h) {
169                 int[] data = new int[w*h];
170 
171                 // compute distance from each point to the center, and figure out the distance from
172                 // it.
173                 int index = 0;
174                 float[] pt1 = new float[2];
175                 float[] pt2 = new float[2];
176 
177                 for (int iy = 0 ; iy < h ; iy++) {
178                     for (int ix = 0 ; ix < w ; ix++) {
179                         // handle the canvas transform
180                         pt1[0] = x + ix;
181                         pt1[1] = y + iy;
182                         mCanvasMatrix.transform(pt1, 0, pt2, 0, 1);
183 
184                         // handle the local matrix
185                         pt1[0] = pt2[0];
186                         pt1[1] = pt2[1];
187                         mLocalMatrix.transform(pt1, 0, pt2, 0, 1);
188 
189                         float _x = pt2[0] - mX;
190                         float _y = pt2[1] - mY;
191                         float distance = (float) Math.hypot(_x, _y);
192 
193                         data[index++] = getGradientColor(distance / mRadius);
194                     }
195                 }
196 
197                 DataBufferInt dataBuffer = new DataBufferInt(data, data.length);
198                 SampleModel colorModel = mColorModel.createCompatibleSampleModel(w, h);
199                 return Raster.createWritableRaster(colorModel, dataBuffer, null);
200             }
201 
202         }
203     }
204 
205 }
206