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 import android.annotation.NonNull;
20 import android.annotation.Nullable;
21 import android.annotation.ColorInt;
22 
23 public class RadialGradient extends Shader {
24 
25     private static final int TYPE_COLORS_AND_POSITIONS = 1;
26     private static final int TYPE_COLOR_CENTER_AND_COLOR_EDGE = 2;
27 
28     /**
29      * Type of the RadialGradient: can be either TYPE_COLORS_AND_POSITIONS or
30      * TYPE_COLOR_CENTER_AND_COLOR_EDGE.
31      */
32     private int mType;
33 
34     private float mX;
35     private float mY;
36     private float mRadius;
37     private int[] mColors;
38     private float[] mPositions;
39     private int mCenterColor;
40     private int mEdgeColor;
41 
42     private TileMode mTileMode;
43 
44     /**
45      * Create a shader that draws a radial gradient given the center and radius.
46      *
47      * @param centerX  The x-coordinate of the center of the radius
48      * @param centerY  The y-coordinate of the center of the radius
49      * @param radius   Must be positive. The radius of the circle for this gradient.
50      * @param colors   The colors to be distributed between the center and edge of the circle
51      * @param stops    May be <code>null</code>. Valid values are between <code>0.0f</code> and
52      *                 <code>1.0f</code>. The relative position of each corresponding color in
53      *                 the colors array. If <code>null</code>, colors are distributed evenly
54      *                 between the center and edge of the circle.
55      * @param tileMode The Shader tiling mode
56      */
RadialGradient(float centerX, float centerY, float radius, @NonNull @ColorInt int colors[], @Nullable float stops[], @NonNull TileMode tileMode)57     public RadialGradient(float centerX, float centerY, float radius,
58             @NonNull @ColorInt int colors[], @Nullable float stops[],
59             @NonNull TileMode tileMode) {
60         if (radius <= 0) {
61             throw new IllegalArgumentException("radius must be > 0");
62         }
63         if (colors.length < 2) {
64             throw new IllegalArgumentException("needs >= 2 number of colors");
65         }
66         if (stops != null && colors.length != stops.length) {
67             throw new IllegalArgumentException("color and position arrays must be of equal length");
68         }
69         mType = TYPE_COLORS_AND_POSITIONS;
70         mX = centerX;
71         mY = centerY;
72         mRadius = radius;
73         mColors = colors.clone();
74         mPositions = stops != null ? stops.clone() : null;
75         mTileMode = tileMode;
76     }
77 
78     /**
79      * Create a shader that draws a radial gradient given the center and radius.
80      *
81      * @param centerX     The x-coordinate of the center of the radius
82      * @param centerY     The y-coordinate of the center of the radius
83      * @param radius      Must be positive. The radius of the circle for this gradient
84      * @param centerColor The color at the center of the circle.
85      * @param edgeColor   The color at the edge of the circle.
86      * @param tileMode    The Shader tiling mode
87      */
RadialGradient(float centerX, float centerY, float radius, @ColorInt int centerColor, @ColorInt int edgeColor, @NonNull TileMode tileMode)88     public RadialGradient(float centerX, float centerY, float radius,
89             @ColorInt int centerColor, @ColorInt int edgeColor, @NonNull TileMode tileMode) {
90         if (radius <= 0) {
91             throw new IllegalArgumentException("radius must be > 0");
92         }
93         mType = TYPE_COLOR_CENTER_AND_COLOR_EDGE;
94         mX = centerX;
95         mY = centerY;
96         mRadius = radius;
97         mCenterColor = centerColor;
98         mEdgeColor = edgeColor;
99         mTileMode = tileMode;
100     }
101 
102     @Override
createNativeInstance(long nativeMatrix)103     long createNativeInstance(long nativeMatrix) {
104         if (mType == TYPE_COLORS_AND_POSITIONS) {
105             return nativeCreate1(nativeMatrix, mX, mY, mRadius,
106                     mColors, mPositions, mTileMode.nativeInt);
107         } else { // TYPE_COLOR_CENTER_AND_COLOR_EDGE
108             return nativeCreate2(nativeMatrix, mX, mY, mRadius,
109                     mCenterColor, mEdgeColor, mTileMode.nativeInt);
110         }
111     }
112 
113     /**
114      * @hide
115      */
116     @Override
copy()117     protected Shader copy() {
118         final RadialGradient copy;
119         if (mType == TYPE_COLORS_AND_POSITIONS) {
120             copy = new RadialGradient(mX, mY, mRadius, mColors.clone(),
121                     mPositions != null ? mPositions.clone() : null, mTileMode);
122         } else { // TYPE_COLOR_CENTER_AND_COLOR_EDGE
123             copy = new RadialGradient(mX, mY, mRadius, mCenterColor, mEdgeColor, mTileMode);
124         }
125         copyLocalMatrix(copy);
126         return copy;
127     }
128 
nativeCreate1(long matrix, float x, float y, float radius, int colors[], float positions[], int tileMode)129     private static native long nativeCreate1(long matrix, float x, float y, float radius,
130             int colors[], float positions[], int tileMode);
nativeCreate2(long matrix, float x, float y, float radius, int color0, int color1, int tileMode)131     private static native long nativeCreate2(long matrix, float x, float y, float radius,
132             int color0, int color1, int tileMode);
133 }
134 
135