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 public class LinearGradient extends Shader { 20 21 private static final int TYPE_COLORS_AND_POSITIONS = 1; 22 private static final int TYPE_COLOR_START_AND_COLOR_END = 2; 23 24 /** 25 * Type of the LinearGradient: can be either TYPE_COLORS_AND_POSITIONS or 26 * TYPE_COLOR_START_AND_COLOR_END. 27 */ 28 private int mType; 29 30 private float mX0; 31 private float mY0; 32 private float mX1; 33 private float mY1; 34 private int[] mColors; 35 private float[] mPositions; 36 private int mColor0; 37 private int mColor1; 38 39 private TileMode mTileMode; 40 41 /** Create a shader that draws a linear gradient along a line. 42 @param x0 The x-coordinate for the start of the gradient line 43 @param y0 The y-coordinate for the start of the gradient line 44 @param x1 The x-coordinate for the end of the gradient line 45 @param y1 The y-coordinate for the end of the gradient line 46 @param colors The colors to be distributed along the gradient line 47 @param positions May be null. The relative positions [0..1] of 48 each corresponding color in the colors array. If this is null, 49 the the colors are distributed evenly along the gradient line. 50 @param tile The Shader tiling mode 51 */ LinearGradient(float x0, float y0, float x1, float y1, int colors[], float positions[], TileMode tile)52 public LinearGradient(float x0, float y0, float x1, float y1, int colors[], float positions[], 53 TileMode tile) { 54 if (colors.length < 2) { 55 throw new IllegalArgumentException("needs >= 2 number of colors"); 56 } 57 if (positions != null && colors.length != positions.length) { 58 throw new IllegalArgumentException("color and position arrays must be of equal length"); 59 } 60 mType = TYPE_COLORS_AND_POSITIONS; 61 mX0 = x0; 62 mY0 = y0; 63 mX1 = x1; 64 mY1 = y1; 65 mColors = colors; 66 mPositions = positions; 67 mTileMode = tile; 68 native_instance = nativeCreate1(x0, y0, x1, y1, colors, positions, tile.nativeInt); 69 native_shader = nativePostCreate1(native_instance, x0, y0, x1, y1, colors, positions, 70 tile.nativeInt); 71 } 72 73 /** Create a shader that draws a linear gradient along a line. 74 @param x0 The x-coordinate for the start of the gradient line 75 @param y0 The y-coordinate for the start of the gradient line 76 @param x1 The x-coordinate for the end of the gradient line 77 @param y1 The y-coordinate for the end of the gradient line 78 @param color0 The color at the start of the gradient line. 79 @param color1 The color at the end of the gradient line. 80 @param tile The Shader tiling mode 81 */ LinearGradient(float x0, float y0, float x1, float y1, int color0, int color1, TileMode tile)82 public LinearGradient(float x0, float y0, float x1, float y1, int color0, int color1, 83 TileMode tile) { 84 mType = TYPE_COLOR_START_AND_COLOR_END; 85 mX0 = x0; 86 mY0 = y0; 87 mX1 = x1; 88 mY1 = y1; 89 mColor0 = color0; 90 mColor1 = color1; 91 mTileMode = tile; 92 native_instance = nativeCreate2(x0, y0, x1, y1, color0, color1, tile.nativeInt); 93 native_shader = nativePostCreate2(native_instance, x0, y0, x1, y1, color0, color1, 94 tile.nativeInt); 95 } 96 97 /** 98 * @hide 99 */ 100 @Override copy()101 protected Shader copy() { 102 final LinearGradient copy; 103 switch (mType) { 104 case TYPE_COLORS_AND_POSITIONS: 105 copy = new LinearGradient(mX0, mY0, mX1, mY1, mColors.clone(), 106 mPositions != null ? mPositions.clone() : null, mTileMode); 107 break; 108 case TYPE_COLOR_START_AND_COLOR_END: 109 copy = new LinearGradient(mX0, mY0, mX1, mY1, mColor0, mColor1, mTileMode); 110 break; 111 default: 112 throw new IllegalArgumentException("LinearGradient should be created with either " + 113 "colors and positions or start color and end color"); 114 } 115 copyLocalMatrix(copy); 116 return copy; 117 } 118 nativeCreate1(float x0, float y0, float x1, float y1, int colors[], float positions[], int tileMode)119 private native int nativeCreate1(float x0, float y0, float x1, float y1, 120 int colors[], float positions[], int tileMode); nativeCreate2(float x0, float y0, float x1, float y1, int color0, int color1, int tileMode)121 private native int nativeCreate2(float x0, float y0, float x1, float y1, 122 int color0, int color1, int tileMode); nativePostCreate1(int native_shader, float x0, float y0, float x1, float y1, int colors[], float positions[], int tileMode)123 private native int nativePostCreate1(int native_shader, float x0, float y0, float x1, float y1, 124 int colors[], float positions[], int tileMode); nativePostCreate2(int native_shader, float x0, float y0, float x1, float y1, int color0, int color1, int tileMode)125 private native int nativePostCreate2(int native_shader, float x0, float y0, float x1, float y1, 126 int color0, int color1, int tileMode); 127 } 128