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 java.awt.image.DataBufferInt; 25 import java.awt.image.Raster; 26 import java.awt.image.SampleModel; 27 28 /** 29 * Delegate implementing the native methods of android.graphics.SweepGradient 30 * 31 * Through the layoutlib_create tool, the original native methods of SweepGradient have been 32 * replaced by calls to methods of the same name in this delegate class. 33 * 34 * This class behaves like the original native implementation, but in Java, keeping previously 35 * native data into its own objects and mapping them to int that are sent back and forth between 36 * it and the original SweepGradient class. 37 * 38 * Because this extends {@link Shader_Delegate}, there's no need to use a {@link DelegateManager}, 39 * as all the Shader classes will be added to the manager owned by {@link Shader_Delegate}. 40 * 41 * @see Shader_Delegate 42 * 43 */ 44 public class SweepGradient_Delegate extends Gradient_Delegate { 45 46 // ---- delegate data ---- 47 private java.awt.Paint mJavaPaint; 48 49 // ---- Public Helper methods ---- 50 51 @Override 52 public java.awt.Paint getJavaPaint() { 53 return mJavaPaint; 54 } 55 56 // ---- native methods ---- 57 58 @LayoutlibDelegate 59 /*package*/ static long nativeCreate1(long matrix, float x, float y, int colors[], float 60 positions[]) { 61 SweepGradient_Delegate newDelegate = new SweepGradient_Delegate(matrix, x, y, colors, 62 positions); 63 return sManager.addNewDelegate(newDelegate); 64 } 65 66 @LayoutlibDelegate 67 /*package*/ static long nativeCreate2(long matrix, float x, float y, int color0, int color1) { 68 return nativeCreate1(matrix, x, y, new int[] { color0, color1 }, 69 null /*positions*/); 70 } 71 72 // ---- Private delegate/helper methods ---- 73 74 /** 75 * A subclass of Shader that draws a sweep gradient around a center point. 76 * 77 * @param nativeMatrix reference to the shader's native transformation matrix 78 * @param cx The x-coordinate of the center 79 * @param cy The y-coordinate of the center 80 * @param colors The colors to be distributed between around the center. 81 * There must be at least 2 colors in the array. 82 * @param positions May be NULL. The relative position of 83 * each corresponding color in the colors array, beginning 84 * with 0 and ending with 1.0. If the values are not 85 * monotonic, the drawing may produce unexpected results. 86 * If positions is NULL, then the colors are automatically 87 * spaced evenly. 88 */ 89 private SweepGradient_Delegate(long nativeMatrix, float cx, float cy, 90 int colors[], float positions[]) { 91 super(nativeMatrix, colors, positions); 92 mJavaPaint = new SweepGradientPaint(cx, cy, mColors, mPositions); 93 } 94 95 private class SweepGradientPaint extends GradientPaint { 96 97 private final float mCx; 98 private final float mCy; 99 100 public SweepGradientPaint(float cx, float cy, int[] colors, 101 float[] positions) { 102 super(colors, positions, null /*tileMode*/); 103 mCx = cx; 104 mCy = cy; 105 } 106 107 @Override 108 public java.awt.PaintContext createContext( 109 java.awt.image.ColorModel colorModel, 110 java.awt.Rectangle deviceBounds, 111 java.awt.geom.Rectangle2D userBounds, 112 java.awt.geom.AffineTransform xform, 113 java.awt.RenderingHints hints) { 114 precomputeGradientColors(); 115 116 java.awt.geom.AffineTransform canvasMatrix; 117 try { 118 canvasMatrix = xform.createInverse(); 119 } catch (java.awt.geom.NoninvertibleTransformException e) { 120 Bridge.getLog().fidelityWarning(LayoutLog.TAG_MATRIX_INVERSE, 121 "Unable to inverse matrix in SweepGradient", e, null /*data*/); 122 canvasMatrix = new java.awt.geom.AffineTransform(); 123 } 124 125 java.awt.geom.AffineTransform localMatrix = getLocalMatrix(); 126 try { 127 localMatrix = localMatrix.createInverse(); 128 } catch (java.awt.geom.NoninvertibleTransformException e) { 129 Bridge.getLog().fidelityWarning(LayoutLog.TAG_MATRIX_INVERSE, 130 "Unable to inverse matrix in SweepGradient", e, null /*data*/); 131 localMatrix = new java.awt.geom.AffineTransform(); 132 } 133 134 return new SweepGradientPaintContext(canvasMatrix, localMatrix, colorModel); 135 } 136 137 private class SweepGradientPaintContext implements java.awt.PaintContext { 138 139 private final java.awt.geom.AffineTransform mCanvasMatrix; 140 private final java.awt.geom.AffineTransform mLocalMatrix; 141 private final java.awt.image.ColorModel mColorModel; 142 143 public SweepGradientPaintContext( 144 java.awt.geom.AffineTransform canvasMatrix, 145 java.awt.geom.AffineTransform localMatrix, 146 java.awt.image.ColorModel colorModel) { 147 mCanvasMatrix = canvasMatrix; 148 mLocalMatrix = localMatrix; 149 mColorModel = colorModel; 150 } 151 152 @Override 153 public void dispose() { 154 } 155 156 @Override 157 public java.awt.image.ColorModel getColorModel() { 158 return mColorModel; 159 } 160 161 @Override 162 public java.awt.image.Raster getRaster(int x, int y, int w, int h) { 163 164 int[] data = new int[w*h]; 165 166 // compute angle from each point to the center, and figure out the distance from 167 // it. 168 int index = 0; 169 float[] pt1 = new float[2]; 170 float[] pt2 = new float[2]; 171 for (int iy = 0 ; iy < h ; iy++) { 172 for (int ix = 0 ; ix < w ; ix++) { 173 // handle the canvas transform 174 pt1[0] = x + ix; 175 pt1[1] = y + iy; 176 mCanvasMatrix.transform(pt1, 0, pt2, 0, 1); 177 178 // handle the local matrix 179 pt1[0] = pt2[0] - mCx; 180 pt1[1] = pt2[1] - mCy; 181 mLocalMatrix.transform(pt1, 0, pt2, 0, 1); 182 183 float dx = pt2[0]; 184 float dy = pt2[1]; 185 186 float angle; 187 if (dx == 0) { 188 angle = (float) (dy < 0 ? 3 * Math.PI / 2 : Math.PI / 2); 189 } else if (dy == 0) { 190 angle = (float) (dx < 0 ? Math.PI : 0); 191 } else { 192 angle = (float) Math.atan(dy / dx); 193 if (dx > 0) { 194 if (dy < 0) { 195 angle += Math.PI * 2; 196 } 197 } else { 198 angle += Math.PI; 199 } 200 } 201 202 // convert to 0-1. value and get color 203 data[index++] = getGradientColor((float) (angle / (2 * Math.PI))); 204 } 205 } 206 207 DataBufferInt dataBuffer = new DataBufferInt(data, data.length); 208 SampleModel colorModel = mColorModel.createCompatibleSampleModel(w, h); 209 return Raster.createWritableRaster(colorModel, dataBuffer, null); 210 } 211 212 } 213 } 214 } 215
