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 48 public java.awt.Paint getJavaPaint() { 49 return mJavaPaint; 50 } 51 52 // ---- native methods ---- 53 54 @LayoutlibDelegate 55 /*package*/ static long nativeCreate1(float x, float y, int colors[], float positions[]) { 56 SweepGradient_Delegate newDelegate = new SweepGradient_Delegate(x, y, colors, positions); 57 return sManager.addNewDelegate(newDelegate); 58 } 59 60 @LayoutlibDelegate 61 /*package*/ static long nativeCreate2(float x, float y, int color0, int color1) { 62 return nativeCreate1(x, y, new int[] { color0, color1 }, null /*positions*/); 63 } 64 65 // ---- Private delegate/helper methods ---- 66 67 /** 68 * A subclass of Shader that draws a sweep gradient around a center point. 69 * 70 * @param cx The x-coordinate of the center 71 * @param cy The y-coordinate of the center 72 * @param colors The colors to be distributed between around the center. 73 * There must be at least 2 colors in the array. 74 * @param positions May be NULL. The relative position of 75 * each corresponding color in the colors array, beginning 76 * with 0 and ending with 1.0. If the values are not 77 * monotonic, the drawing may produce unexpected results. 78 * If positions is NULL, then the colors are automatically 79 * spaced evenly. 80 */ 81 private SweepGradient_Delegate(float cx, float cy, 82 int colors[], float positions[]) { 83 super(colors, positions); 84 mJavaPaint = new SweepGradientPaint(cx, cy, mColors, mPositions); 85 } 86 87 private class SweepGradientPaint extends GradientPaint { 88 89 private final float mCx; 90 private final float mCy; 91 92 public SweepGradientPaint(float cx, float cy, int[] colors, 93 float[] positions) { 94 super(colors, positions, null /*tileMode*/); 95 mCx = cx; 96 mCy = cy; 97 } 98 99 @Override 100 public java.awt.PaintContext createContext( 101 java.awt.image.ColorModel colorModel, 102 java.awt.Rectangle deviceBounds, 103 java.awt.geom.Rectangle2D userBounds, 104 java.awt.geom.AffineTransform xform, 105 java.awt.RenderingHints hints) { 106 precomputeGradientColors(); 107 108 java.awt.geom.AffineTransform canvasMatrix; 109 try { 110 canvasMatrix = xform.createInverse(); 111 } catch (java.awt.geom.NoninvertibleTransformException e) { 112 Bridge.getLog().fidelityWarning(LayoutLog.TAG_MATRIX_INVERSE, 113 "Unable to inverse matrix in SweepGradient", e, null /*data*/); 114 canvasMatrix = new java.awt.geom.AffineTransform(); 115 } 116 117 java.awt.geom.AffineTransform localMatrix = getLocalMatrix(); 118 try { 119 localMatrix = localMatrix.createInverse(); 120 } catch (java.awt.geom.NoninvertibleTransformException e) { 121 Bridge.getLog().fidelityWarning(LayoutLog.TAG_MATRIX_INVERSE, 122 "Unable to inverse matrix in SweepGradient", e, null /*data*/); 123 localMatrix = new java.awt.geom.AffineTransform(); 124 } 125 126 return new SweepGradientPaintContext(canvasMatrix, localMatrix, colorModel); 127 } 128 129 private class SweepGradientPaintContext implements java.awt.PaintContext { 130 131 private final java.awt.geom.AffineTransform mCanvasMatrix; 132 private final java.awt.geom.AffineTransform mLocalMatrix; 133 private final java.awt.image.ColorModel mColorModel; 134 135 public SweepGradientPaintContext( 136 java.awt.geom.AffineTransform canvasMatrix, 137 java.awt.geom.AffineTransform localMatrix, 138 java.awt.image.ColorModel colorModel) { 139 mCanvasMatrix = canvasMatrix; 140 mLocalMatrix = localMatrix; 141 mColorModel = colorModel; 142 } 143 144 @Override 145 public void dispose() { 146 } 147 148 @Override 149 public java.awt.image.ColorModel getColorModel() { 150 return mColorModel; 151 } 152 153 @Override 154 public java.awt.image.Raster getRaster(int x, int y, int w, int h) { 155 java.awt.image.BufferedImage image = new java.awt.image.BufferedImage(w, h, 156 java.awt.image.BufferedImage.TYPE_INT_ARGB); 157 158 int[] data = new int[w*h]; 159 160 // compute angle from each point to the center, and figure out the distance from 161 // it. 162 int index = 0; 163 float[] pt1 = new float[2]; 164 float[] pt2 = new float[2]; 165 for (int iy = 0 ; iy < h ; iy++) { 166 for (int ix = 0 ; ix < w ; ix++) { 167 // handle the canvas transform 168 pt1[0] = x + ix; 169 pt1[1] = y + iy; 170 mCanvasMatrix.transform(pt1, 0, pt2, 0, 1); 171 172 // handle the local matrix 173 pt1[0] = pt2[0] - mCx; 174 pt1[1] = pt2[1] - mCy; 175 mLocalMatrix.transform(pt1, 0, pt2, 0, 1); 176 177 float dx = pt2[0]; 178 float dy = pt2[1]; 179 180 float angle; 181 if (dx == 0) { 182 angle = (float) (dy < 0 ? 3 * Math.PI / 2 : Math.PI / 2); 183 } else if (dy == 0) { 184 angle = (float) (dx < 0 ? Math.PI : 0); 185 } else { 186 angle = (float) Math.atan(dy / dx); 187 if (dx > 0) { 188 if (dy < 0) { 189 angle += Math.PI * 2; 190 } 191 } else { 192 angle += Math.PI; 193 } 194 } 195 196 // convert to 0-1. value and get color 197 data[index++] = getGradientColor((float) (angle / (2 * Math.PI))); 198 } 199 } 200 201 image.setRGB(0 /*startX*/, 0 /*startY*/, w, h, data, 0 /*offset*/, w /*scansize*/); 202 203 return image.getRaster(); 204 } 205 206 } 207 } 208 } 209
