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.ILayoutLog; 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 getJavaPaint()52 public java.awt.Paint getJavaPaint() { 53 return mJavaPaint; 54 } 55 56 // ---- native methods ---- 57 58 @LayoutlibDelegate nativeCreate(long matrix, float x, float y, long[] colors, float[] positions, long colorSpaceHandle)59 /*package*/ static long nativeCreate(long matrix, float x, float y, long[] colors, 60 float[] positions, long colorSpaceHandle) { 61 SweepGradient_Delegate newDelegate = new SweepGradient_Delegate(matrix, x, y, colors, 62 positions); 63 return sManager.addNewDelegate(newDelegate); 64 } 65 66 // ---- Private delegate/helper methods ---- 67 68 /** 69 * A subclass of Shader that draws a sweep gradient around a center point. 70 * 71 * @param nativeMatrix reference to the shader's native transformation matrix 72 * @param cx The x-coordinate of the center 73 * @param cy The y-coordinate of the center 74 * @param colors The colors to be distributed between around the center. 75 * There must be at least 2 colors in the array. 76 * @param positions May be NULL. The relative position of 77 * each corresponding color in the colors array, beginning 78 * with 0 and ending with 1.0. If the values are not 79 * monotonic, the drawing may produce unexpected results. 80 * If positions is NULL, then the colors are automatically 81 * spaced evenly. 82 */ SweepGradient_Delegate(long nativeMatrix, float cx, float cy, long[] colors, float[] positions)83 private SweepGradient_Delegate(long nativeMatrix, float cx, float cy, 84 long[] colors, float[] positions) { 85 super(nativeMatrix, colors, positions); 86 mJavaPaint = new SweepGradientPaint(cx, cy, mColors, mPositions); 87 } 88 89 private class SweepGradientPaint extends GradientPaint { 90 91 private final float mCx; 92 private final float mCy; 93 SweepGradientPaint(float cx, float cy, int[] colors, float[] positions)94 public SweepGradientPaint(float cx, float cy, int[] colors, 95 float[] positions) { 96 super(colors, positions, null /*tileMode*/); 97 mCx = cx; 98 mCy = cy; 99 } 100 101 @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)102 public java.awt.PaintContext createContext( 103 java.awt.image.ColorModel colorModel, 104 java.awt.Rectangle deviceBounds, 105 java.awt.geom.Rectangle2D userBounds, 106 java.awt.geom.AffineTransform xform, 107 java.awt.RenderingHints hints) { 108 precomputeGradientColors(); 109 110 java.awt.geom.AffineTransform canvasMatrix; 111 try { 112 canvasMatrix = xform.createInverse(); 113 } catch (java.awt.geom.NoninvertibleTransformException e) { 114 Bridge.getLog().fidelityWarning(ILayoutLog.TAG_MATRIX_INVERSE, 115 "Unable to inverse matrix in SweepGradient", e, null, null /*data*/); 116 canvasMatrix = new java.awt.geom.AffineTransform(); 117 } 118 119 java.awt.geom.AffineTransform localMatrix = getLocalMatrix(); 120 try { 121 localMatrix = localMatrix.createInverse(); 122 } catch (java.awt.geom.NoninvertibleTransformException e) { 123 Bridge.getLog().fidelityWarning(ILayoutLog.TAG_MATRIX_INVERSE, 124 "Unable to inverse matrix in SweepGradient", e, null, null /*data*/); 125 localMatrix = new java.awt.geom.AffineTransform(); 126 } 127 128 return new SweepGradientPaintContext(canvasMatrix, localMatrix, colorModel); 129 } 130 131 private class SweepGradientPaintContext implements java.awt.PaintContext { 132 133 private final java.awt.geom.AffineTransform mCanvasMatrix; 134 private final java.awt.geom.AffineTransform mLocalMatrix; 135 private final java.awt.image.ColorModel mColorModel; 136 SweepGradientPaintContext( java.awt.geom.AffineTransform canvasMatrix, java.awt.geom.AffineTransform localMatrix, java.awt.image.ColorModel colorModel)137 public SweepGradientPaintContext( 138 java.awt.geom.AffineTransform canvasMatrix, 139 java.awt.geom.AffineTransform localMatrix, 140 java.awt.image.ColorModel colorModel) { 141 mCanvasMatrix = canvasMatrix; 142 mLocalMatrix = localMatrix; 143 mColorModel = colorModel; 144 } 145 146 @Override dispose()147 public void dispose() { 148 } 149 150 @Override getColorModel()151 public java.awt.image.ColorModel getColorModel() { 152 return mColorModel; 153 } 154 155 @Override getRaster(int x, int y, int w, int h)156 public java.awt.image.Raster getRaster(int x, int y, int w, int h) { 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 DataBufferInt dataBuffer = new DataBufferInt(data, data.length); 202 SampleModel colorModel = mColorModel.createCompatibleSampleModel(w, h); 203 return Raster.createWritableRaster(colorModel, dataBuffer, null); 204 } 205 206 } 207 } 208 } 209