1 /* 2 * Copyright (C) 2007 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 /** A subclass of shader that returns the composition of two other shaders, combined by 20 an {@link android.graphics.Xfermode} subclass. 21 */ 22 public class ComposeShader extends Shader { 23 24 private static final int TYPE_XFERMODE = 1; 25 private static final int TYPE_PORTERDUFFMODE = 2; 26 27 /** 28 * Type of the ComposeShader: can be either TYPE_XFERMODE or TYPE_PORTERDUFFMODE 29 */ 30 private int mType; 31 32 private Xfermode mXferMode; 33 private PorterDuff.Mode mPorterDuffMode; 34 35 /** 36 * Hold onto the shaders to avoid GC. 37 */ 38 @SuppressWarnings({"UnusedDeclaration"}) 39 private final Shader mShaderA; 40 @SuppressWarnings({"UnusedDeclaration"}) 41 private final Shader mShaderB; 42 43 /** Create a new compose shader, given shaders A, B, and a combining mode. 44 When the mode is applied, it will be given the result from shader A as its 45 "dst", and the result from shader B as its "src". 46 @param shaderA The colors from this shader are seen as the "dst" by the mode 47 @param shaderB The colors from this shader are seen as the "src" by the mode 48 @param mode The mode that combines the colors from the two shaders. If mode 49 is null, then SRC_OVER is assumed. 50 */ ComposeShader(Shader shaderA, Shader shaderB, Xfermode mode)51 public ComposeShader(Shader shaderA, Shader shaderB, Xfermode mode) { 52 mType = TYPE_XFERMODE; 53 mShaderA = shaderA; 54 mShaderB = shaderB; 55 mXferMode = mode; 56 init(nativeCreate1(shaderA.getNativeInstance(), shaderB.getNativeInstance(), 57 (mode != null) ? mode.native_instance : 0)); 58 } 59 60 /** Create a new compose shader, given shaders A, B, and a combining PorterDuff mode. 61 When the mode is applied, it will be given the result from shader A as its 62 "dst", and the result from shader B as its "src". 63 @param shaderA The colors from this shader are seen as the "dst" by the mode 64 @param shaderB The colors from this shader are seen as the "src" by the mode 65 @param mode The PorterDuff mode that combines the colors from the two shaders. 66 */ ComposeShader(Shader shaderA, Shader shaderB, PorterDuff.Mode mode)67 public ComposeShader(Shader shaderA, Shader shaderB, PorterDuff.Mode mode) { 68 mType = TYPE_PORTERDUFFMODE; 69 mShaderA = shaderA; 70 mShaderB = shaderB; 71 mPorterDuffMode = mode; 72 init(nativeCreate2(shaderA.getNativeInstance(), shaderB.getNativeInstance(), 73 mode.nativeInt)); 74 } 75 76 /** 77 * @hide 78 */ 79 @Override copy()80 protected Shader copy() { 81 final ComposeShader copy; 82 switch (mType) { 83 case TYPE_XFERMODE: 84 copy = new ComposeShader(mShaderA.copy(), mShaderB.copy(), mXferMode); 85 break; 86 case TYPE_PORTERDUFFMODE: 87 copy = new ComposeShader(mShaderA.copy(), mShaderB.copy(), mPorterDuffMode); 88 break; 89 default: 90 throw new IllegalArgumentException( 91 "ComposeShader should be created with either Xfermode or PorterDuffMode"); 92 } 93 copyLocalMatrix(copy); 94 return copy; 95 } 96 nativeCreate1(long native_shaderA, long native_shaderB, long native_mode)97 private static native long nativeCreate1(long native_shaderA, long native_shaderB, 98 long native_mode); nativeCreate2(long native_shaderA, long native_shaderB, int porterDuffMode)99 private static native long nativeCreate2(long native_shaderA, long native_shaderB, 100 int porterDuffMode); 101 } 102