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 /** 27 * Delegate implementing the native methods of android.graphics.LinearGradient 28 * 29 * Through the layoutlib_create tool, the original native methods of LinearGradient have been 30 * replaced by calls to methods of the same name in this delegate class. 31 * 32 * This class behaves like the original native implementation, but in Java, keeping previously 33 * native data into its own objects and mapping them to int that are sent back and forth between 34 * it and the original LinearGradient class. 35 * 36 * Because this extends {@link Shader_Delegate}, there's no need to use a {@link DelegateManager}, 37 * as all the Shader classes will be added to the manager owned by {@link Shader_Delegate}. 38 * 39 * @see Shader_Delegate 40 * 41 */ 42 public final class LinearGradient_Delegate extends Gradient_Delegate { 43 44 // ---- delegate data ---- 45 private java.awt.Paint mJavaPaint; 46 47 // ---- Public Helper methods ---- 48 49 @Override 50 public java.awt.Paint getJavaPaint() { 51 return mJavaPaint; 52 } 53 54 // ---- native methods ---- 55 56 @LayoutlibDelegate 57 /*package*/ static int nativeCreate1(LinearGradient thisGradient, 58 float x0, float y0, float x1, float y1, 59 int colors[], float positions[], int tileMode) { 60 LinearGradient_Delegate newDelegate = new LinearGradient_Delegate(x0, y0, x1, y1, 61 colors, positions, Shader_Delegate.getTileMode(tileMode)); 62 return sManager.addNewDelegate(newDelegate); 63 } 64 65 @LayoutlibDelegate 66 /*package*/ static int nativeCreate2(LinearGradient thisGradient, 67 float x0, float y0, float x1, float y1, 68 int color0, int color1, int tileMode) { 69 return nativeCreate1(thisGradient, 70 x0, y0, x1, y1, new int[] { color0, color1}, null /*positions*/, 71 tileMode); 72 } 73 74 @LayoutlibDelegate 75 /*package*/ static int nativePostCreate1(LinearGradient thisGradient, 76 int native_shader, float x0, float y0, float x1, float y1, 77 int colors[], float positions[], int tileMode) { 78 // nothing to be done here. 79 return 0; 80 } 81 82 @LayoutlibDelegate 83 /*package*/ static int nativePostCreate2(LinearGradient thisGradient, 84 int native_shader, float x0, float y0, float x1, float y1, 85 int color0, int color1, int tileMode) { 86 // nothing to be done here. 87 return 0; 88 } 89 90 // ---- Private delegate/helper methods ---- 91 92 /** 93 * Create a shader that draws a linear gradient along a line. 94 * 95 * @param x0 The x-coordinate for the start of the gradient line 96 * @param y0 The y-coordinate for the start of the gradient line 97 * @param x1 The x-coordinate for the end of the gradient line 98 * @param y1 The y-coordinate for the end of the gradient line 99 * @param colors The colors to be distributed along the gradient line 100 * @param positions May be null. The relative positions [0..1] of each 101 * corresponding color in the colors array. If this is null, the 102 * the colors are distributed evenly along the gradient line. 103 * @param tile The Shader tiling mode 104 */ 105 private LinearGradient_Delegate(float x0, float y0, float x1, float y1, 106 int colors[], float positions[], TileMode tile) { 107 super(colors, positions); 108 mJavaPaint = new LinearGradientPaint(x0, y0, x1, y1, mColors, mPositions, tile); 109 } 110 111 // ---- Custom Java Paint ---- 112 /** 113 * Linear Gradient (Java) Paint able to handle more than 2 points, as 114 * {@link java.awt.GradientPaint} only supports 2 points and does not support Android's tile 115 * modes. 116 */ 117 private class LinearGradientPaint extends GradientPaint { 118 119 private final float mX0; 120 private final float mY0; 121 private final float mDx; 122 private final float mDy; 123 private final float mDSize2; 124 125 public LinearGradientPaint(float x0, float y0, float x1, float y1, int colors[], 126 float positions[], TileMode tile) { 127 super(colors, positions, tile); 128 mX0 = x0; 129 mY0 = y0; 130 mDx = x1 - x0; 131 mDy = y1 - y0; 132 mDSize2 = mDx * mDx + mDy * mDy; 133 } 134 135 @Override 136 public java.awt.PaintContext createContext( 137 java.awt.image.ColorModel colorModel, 138 java.awt.Rectangle deviceBounds, 139 java.awt.geom.Rectangle2D userBounds, 140 java.awt.geom.AffineTransform xform, 141 java.awt.RenderingHints hints) { 142 precomputeGradientColors(); 143 144 java.awt.geom.AffineTransform canvasMatrix; 145 try { 146 canvasMatrix = xform.createInverse(); 147 } catch (java.awt.geom.NoninvertibleTransformException e) { 148 Bridge.getLog().fidelityWarning(LayoutLog.TAG_MATRIX_INVERSE, 149 "Unable to inverse matrix in LinearGradient", e, null /*data*/); 150 canvasMatrix = new java.awt.geom.AffineTransform(); 151 } 152 153 java.awt.geom.AffineTransform localMatrix = getLocalMatrix(); 154 try { 155 localMatrix = localMatrix.createInverse(); 156 } catch (java.awt.geom.NoninvertibleTransformException e) { 157 Bridge.getLog().fidelityWarning(LayoutLog.TAG_MATRIX_INVERSE, 158 "Unable to inverse matrix in LinearGradient", e, null /*data*/); 159 localMatrix = new java.awt.geom.AffineTransform(); 160 } 161 162 return new LinearGradientPaintContext(canvasMatrix, localMatrix, colorModel); 163 } 164 165 private class LinearGradientPaintContext implements java.awt.PaintContext { 166 167 private final java.awt.geom.AffineTransform mCanvasMatrix; 168 private final java.awt.geom.AffineTransform mLocalMatrix; 169 private final java.awt.image.ColorModel mColorModel; 170 171 private LinearGradientPaintContext( 172 java.awt.geom.AffineTransform canvasMatrix, 173 java.awt.geom.AffineTransform localMatrix, 174 java.awt.image.ColorModel colorModel) { 175 mCanvasMatrix = canvasMatrix; 176 mLocalMatrix = localMatrix; 177 mColorModel = colorModel; 178 } 179 180 @Override 181 public void dispose() { 182 } 183 184 @Override 185 public java.awt.image.ColorModel getColorModel() { 186 return mColorModel; 187 } 188 189 @Override 190 public java.awt.image.Raster getRaster(int x, int y, int w, int h) { 191 java.awt.image.BufferedImage image = new java.awt.image.BufferedImage(w, h, 192 java.awt.image.BufferedImage.TYPE_INT_ARGB); 193 194 int[] data = new int[w*h]; 195 196 int index = 0; 197 float[] pt1 = new float[2]; 198 float[] pt2 = new float[2]; 199 for (int iy = 0 ; iy < h ; iy++) { 200 for (int ix = 0 ; ix < w ; ix++) { 201 // handle the canvas transform 202 pt1[0] = x + ix; 203 pt1[1] = y + iy; 204 mCanvasMatrix.transform(pt1, 0, pt2, 0, 1); 205 206 // handle the local matrix. 207 pt1[0] = pt2[0]; 208 pt1[1] = pt2[1]; 209 mLocalMatrix.transform(pt1, 0, pt2, 0, 1); 210 211 data[index++] = getColor(pt2[0], pt2[1]); 212 } 213 } 214 215 image.setRGB(0 /*startX*/, 0 /*startY*/, w, h, data, 0 /*offset*/, w /*scansize*/); 216 217 return image.getRaster(); 218 } 219 } 220 221 /** 222 * Returns a color for an arbitrary point. 223 */ 224 private int getColor(float x, float y) { 225 float pos; 226 if (mDx == 0) { 227 pos = (y - mY0) / mDy; 228 } else if (mDy == 0) { 229 pos = (x - mX0) / mDx; 230 } else { 231 // find the x position on the gradient vector. 232 float _x = (mDx*mDy*(y-mY0) + mDy*mDy*mX0 + mDx*mDx*x) / mDSize2; 233 // from it get the position relative to the vector 234 pos = (_x - mX0) / mDx; 235 } 236 237 return getGradientColor(pos); 238 } 239 } 240 } 241
