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 /** 25 * Delegate implementing the native methods of android.graphics.SweepGradient 26 * 27 * Through the layoutlib_create tool, the original native methods of SweepGradient have been 28 * replaced by calls to methods of the same name in this delegate class. 29 * 30 * This class behaves like the original native implementation, but in Java, keeping previously 31 * native data into its own objects and mapping them to int that are sent back and forth between 32 * it and the original SweepGradient class. 33 * 34 * Because this extends {@link Shader_Delegate}, there's no need to use a {@link DelegateManager}, 35 * as all the Shader classes will be added to the manager owned by {@link Shader_Delegate}. 36 * 37 * @see Shader_Delegate 38 * 39 */ 40 public class SweepGradient_Delegate extends Gradient_Delegate { 41 42 // ---- delegate data ---- 43 private java.awt.Paint mJavaPaint; 44 45 // ---- Public Helper methods ---- 46 47 @Override getJavaPaint()48 public java.awt.Paint getJavaPaint() { 49 return mJavaPaint; 50 } 51 52 // ---- native methods ---- 53 54 @LayoutlibDelegate nativeCreate1(long matrix, float x, float y, int colors[], float positions[])55 /*package*/ static long nativeCreate1(long matrix, float x, float y, int colors[], float 56 positions[]) { 57 SweepGradient_Delegate newDelegate = new SweepGradient_Delegate(matrix, x, y, colors, 58 positions); 59 return sManager.addNewDelegate(newDelegate); 60 } 61 62 @LayoutlibDelegate nativeCreate2(long matrix, float x, float y, int color0, int color1)63 /*package*/ static long nativeCreate2(long matrix, float x, float y, int color0, int color1) { 64 return nativeCreate1(matrix, x, y, new int[] { color0, color1 }, 65 null /*positions*/); 66 } 67 68 // ---- Private delegate/helper methods ---- 69 70 /** 71 * A subclass of Shader that draws a sweep gradient around a center point. 72 * 73 * @param nativeMatrix reference to the shader's native transformation matrix 74 * @param cx The x-coordinate of the center 75 * @param cy The y-coordinate of the center 76 * @param colors The colors to be distributed between around the center. 77 * There must be at least 2 colors in the array. 78 * @param positions May be NULL. The relative position of 79 * each corresponding color in the colors array, beginning 80 * with 0 and ending with 1.0. If the values are not 81 * monotonic, the drawing may produce unexpected results. 82 * If positions is NULL, then the colors are automatically 83 * spaced evenly. 84 */ SweepGradient_Delegate(long nativeMatrix, float cx, float cy, int colors[], float positions[])85 private SweepGradient_Delegate(long nativeMatrix, float cx, float cy, 86 int colors[], float positions[]) { 87 super(nativeMatrix, colors, positions); 88 mJavaPaint = new SweepGradientPaint(cx, cy, mColors, mPositions); 89 } 90 91 private class SweepGradientPaint extends GradientPaint { 92 93 private final float mCx; 94 private final float mCy; 95 SweepGradientPaint(float cx, float cy, int[] colors, float[] positions)96 public SweepGradientPaint(float cx, float cy, int[] colors, 97 float[] positions) { 98 super(colors, positions, null /*tileMode*/); 99 mCx = cx; 100 mCy = cy; 101 } 102 103 @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)104 public java.awt.PaintContext createContext( 105 java.awt.image.ColorModel colorModel, 106 java.awt.Rectangle deviceBounds, 107 java.awt.geom.Rectangle2D userBounds, 108 java.awt.geom.AffineTransform xform, 109 java.awt.RenderingHints hints) { 110 precomputeGradientColors(); 111 112 java.awt.geom.AffineTransform canvasMatrix; 113 try { 114 canvasMatrix = xform.createInverse(); 115 } catch (java.awt.geom.NoninvertibleTransformException e) { 116 Bridge.getLog().fidelityWarning(LayoutLog.TAG_MATRIX_INVERSE, 117 "Unable to inverse matrix in SweepGradient", e, null /*data*/); 118 canvasMatrix = new java.awt.geom.AffineTransform(); 119 } 120 121 java.awt.geom.AffineTransform localMatrix = getLocalMatrix(); 122 try { 123 localMatrix = localMatrix.createInverse(); 124 } catch (java.awt.geom.NoninvertibleTransformException e) { 125 Bridge.getLog().fidelityWarning(LayoutLog.TAG_MATRIX_INVERSE, 126 "Unable to inverse matrix in SweepGradient", e, null /*data*/); 127 localMatrix = new java.awt.geom.AffineTransform(); 128 } 129 130 return new SweepGradientPaintContext(canvasMatrix, localMatrix, colorModel); 131 } 132 133 private class SweepGradientPaintContext implements java.awt.PaintContext { 134 135 private final java.awt.geom.AffineTransform mCanvasMatrix; 136 private final java.awt.geom.AffineTransform mLocalMatrix; 137 private final java.awt.image.ColorModel mColorModel; 138 SweepGradientPaintContext( java.awt.geom.AffineTransform canvasMatrix, java.awt.geom.AffineTransform localMatrix, java.awt.image.ColorModel colorModel)139 public SweepGradientPaintContext( 140 java.awt.geom.AffineTransform canvasMatrix, 141 java.awt.geom.AffineTransform localMatrix, 142 java.awt.image.ColorModel colorModel) { 143 mCanvasMatrix = canvasMatrix; 144 mLocalMatrix = localMatrix; 145 mColorModel = colorModel; 146 } 147 148 @Override dispose()149 public void dispose() { 150 } 151 152 @Override getColorModel()153 public java.awt.image.ColorModel getColorModel() { 154 return mColorModel; 155 } 156 157 @Override getRaster(int x, int y, int w, int h)158 public java.awt.image.Raster getRaster(int x, int y, int w, int h) { 159 java.awt.image.BufferedImage image = new java.awt.image.BufferedImage( 160 mColorModel, mColorModel.createCompatibleWritableRaster(w, h), 161 mColorModel.isAlphaPremultiplied(), null); 162 163 int[] data = new int[w*h]; 164 165 // compute angle from each point to the center, and figure out the distance from 166 // it. 167 int index = 0; 168 float[] pt1 = new float[2]; 169 float[] pt2 = new float[2]; 170 for (int iy = 0 ; iy < h ; iy++) { 171 for (int ix = 0 ; ix < w ; ix++) { 172 // handle the canvas transform 173 pt1[0] = x + ix; 174 pt1[1] = y + iy; 175 mCanvasMatrix.transform(pt1, 0, pt2, 0, 1); 176 177 // handle the local matrix 178 pt1[0] = pt2[0] - mCx; 179 pt1[1] = pt2[1] - mCy; 180 mLocalMatrix.transform(pt1, 0, pt2, 0, 1); 181 182 float dx = pt2[0]; 183 float dy = pt2[1]; 184 185 float angle; 186 if (dx == 0) { 187 angle = (float) (dy < 0 ? 3 * Math.PI / 2 : Math.PI / 2); 188 } else if (dy == 0) { 189 angle = (float) (dx < 0 ? Math.PI : 0); 190 } else { 191 angle = (float) Math.atan(dy / dx); 192 if (dx > 0) { 193 if (dy < 0) { 194 angle += Math.PI * 2; 195 } 196 } else { 197 angle += Math.PI; 198 } 199 } 200 201 // convert to 0-1. value and get color 202 data[index++] = getGradientColor((float) (angle / (2 * Math.PI))); 203 } 204 } 205 206 image.setRGB(0 /*startX*/, 0 /*startY*/, w, h, data, 0 /*offset*/, w /*scansize*/); 207 208 return image.getRaster(); 209 } 210 211 } 212 } 213 } 214