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 import java.awt.image.ColorModel; 27 28 /** 29 * Delegate implementing the native methods of android.graphics.LinearGradient 30 * 31 * Through the layoutlib_create tool, the original native methods of LinearGradient 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 LinearGradient 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 final class LinearGradient_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(LinearGradient thisGradient, long matrix, 60 float x0, float y0, float x1, float y1, 61 int colors[], float positions[], int tileMode) { 62 LinearGradient_Delegate newDelegate = new LinearGradient_Delegate(matrix, x0, y0, 63 x1, y1, colors, positions, Shader_Delegate.getTileMode(tileMode)); 64 return sManager.addNewDelegate(newDelegate); 65 } 66 67 @LayoutlibDelegate 68 /*package*/ static long nativeCreate2(LinearGradient thisGradient, long matrix, 69 float x0, float y0, float x1, float y1, 70 int color0, int color1, int tileMode) { 71 return nativeCreate1(thisGradient, matrix, x0, y0, x1, y1, new int[] { color0, color1}, 72 null /*positions*/, tileMode); 73 } 74 75 // ---- Private delegate/helper methods ---- 76 77 /** 78 * Create a shader that draws a linear gradient along a line. 79 * 80 * @param nativeMatrix reference to the shader's native transformation matrix 81 * @param x0 The x-coordinate for the start of the gradient line 82 * @param y0 The y-coordinate for the start of the gradient line 83 * @param x1 The x-coordinate for the end of the gradient line 84 * @param y1 The y-coordinate for the end of the gradient line 85 * @param colors The colors to be distributed along the gradient line 86 * @param positions May be null. The relative positions [0..1] of each 87 * corresponding color in the colors array. If this is null, the 88 * the colors are distributed evenly along the gradient line. 89 * @param tile The Shader tiling mode 90 */ 91 private LinearGradient_Delegate(long nativeMatrix, float x0, float y0, float x1, 92 float y1, int colors[], float positions[], TileMode tile) { 93 super(nativeMatrix, colors, positions); 94 mJavaPaint = new LinearGradientPaint(x0, y0, x1, y1, mColors, mPositions, tile); 95 } 96 97 // ---- Custom Java Paint ---- 98 /** 99 * Linear Gradient (Java) Paint able to handle more than 2 points, as 100 * {@link java.awt.GradientPaint} only supports 2 points and does not support Android's tile 101 * modes. 102 */ 103 private class LinearGradientPaint extends GradientPaint { 104 105 private final float mX0; 106 private final float mY0; 107 private final float mDx; 108 private final float mDy; 109 private final float mDSize2; 110 111 public LinearGradientPaint(float x0, float y0, float x1, float y1, int colors[], 112 float positions[], TileMode tile) { 113 super(colors, positions, tile); 114 mX0 = x0; 115 mY0 = y0; 116 mDx = x1 - x0; 117 mDy = y1 - y0; 118 mDSize2 = mDx * mDx + mDy * mDy; 119 } 120 121 @Override 122 public java.awt.PaintContext createContext( 123 java.awt.image.ColorModel colorModel, 124 java.awt.Rectangle deviceBounds, 125 java.awt.geom.Rectangle2D userBounds, 126 java.awt.geom.AffineTransform xform, 127 java.awt.RenderingHints hints) { 128 precomputeGradientColors(); 129 130 java.awt.geom.AffineTransform canvasMatrix; 131 try { 132 canvasMatrix = xform.createInverse(); 133 } catch (java.awt.geom.NoninvertibleTransformException e) { 134 Bridge.getLog().fidelityWarning(LayoutLog.TAG_MATRIX_INVERSE, 135 "Unable to inverse matrix in LinearGradient", e, null /*data*/); 136 canvasMatrix = new java.awt.geom.AffineTransform(); 137 } 138 139 java.awt.geom.AffineTransform localMatrix = getLocalMatrix(); 140 try { 141 localMatrix = localMatrix.createInverse(); 142 } catch (java.awt.geom.NoninvertibleTransformException e) { 143 Bridge.getLog().fidelityWarning(LayoutLog.TAG_MATRIX_INVERSE, 144 "Unable to inverse matrix in LinearGradient", e, null /*data*/); 145 localMatrix = new java.awt.geom.AffineTransform(); 146 } 147 148 return new LinearGradientPaintContext(canvasMatrix, localMatrix, colorModel); 149 } 150 151 private class LinearGradientPaintContext implements java.awt.PaintContext { 152 153 private final java.awt.geom.AffineTransform mCanvasMatrix; 154 private final java.awt.geom.AffineTransform mLocalMatrix; 155 private final java.awt.image.ColorModel mColorModel; 156 157 private LinearGradientPaintContext( 158 java.awt.geom.AffineTransform canvasMatrix, 159 java.awt.geom.AffineTransform localMatrix, 160 java.awt.image.ColorModel colorModel) { 161 mCanvasMatrix = canvasMatrix; 162 mLocalMatrix = localMatrix; 163 mColorModel = colorModel.hasAlpha() ? colorModel : ColorModel.getRGBdefault(); 164 } 165 166 @Override 167 public void dispose() { 168 } 169 170 @Override 171 public java.awt.image.ColorModel getColorModel() { 172 return mColorModel; 173 } 174 175 @Override 176 public java.awt.image.Raster getRaster(int x, int y, int w, int h) { 177 java.awt.image.BufferedImage image = new java.awt.image.BufferedImage( 178 mColorModel, mColorModel.createCompatibleWritableRaster(w, h), 179 mColorModel.isAlphaPremultiplied(), null); 180 181 int[] data = new int[w*h]; 182 183 int index = 0; 184 float[] pt1 = new float[2]; 185 float[] pt2 = new float[2]; 186 for (int iy = 0 ; iy < h ; iy++) { 187 for (int ix = 0 ; ix < w ; ix++) { 188 // handle the canvas transform 189 pt1[0] = x + ix; 190 pt1[1] = y + iy; 191 mCanvasMatrix.transform(pt1, 0, pt2, 0, 1); 192 193 // handle the local matrix. 194 pt1[0] = pt2[0]; 195 pt1[1] = pt2[1]; 196 mLocalMatrix.transform(pt1, 0, pt2, 0, 1); 197 198 data[index++] = getColor(pt2[0], pt2[1]); 199 } 200 } 201 202 image.setRGB(0 /*startX*/, 0 /*startY*/, w, h, data, 0 /*offset*/, w /*scansize*/); 203 204 return image.getRaster(); 205 } 206 } 207 208 /** 209 * Returns a color for an arbitrary point. 210 */ 211 private int getColor(float x, float y) { 212 float pos; 213 if (mDx == 0) { 214 pos = (y - mY0) / mDy; 215 } else if (mDy == 0) { 216 pos = (x - mX0) / mDx; 217 } else { 218 // find the x position on the gradient vector. 219 float _x = (mDx*mDy*(y-mY0) + mDy*mDy*mX0 + mDx*mDx*x) / mDSize2; 220 // from it get the position relative to the vector 221 pos = (_x - mX0) / mDx; 222 } 223 224 return getGradientColor(pos); 225 } 226 } 227 } 228
