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.ColorInt;
20 import android.annotation.NonNull;
21 import android.annotation.Nullable;
22 
23 public class SweepGradient extends Shader {
24 
25     private static final int TYPE_COLORS_AND_POSITIONS = 1;
26     private static final int TYPE_COLOR_START_AND_COLOR_END = 2;
27 
28     /**
29      * Type of the LinearGradient: can be either TYPE_COLORS_AND_POSITIONS or
30      * TYPE_COLOR_START_AND_COLOR_END.
31      */
32     private int mType;
33 
34     private float mCx;
35     private float mCy;
36     private int[] mColors;
37     private float[] mPositions;
38     private int mColor0;
39     private int mColor1;
40 
41     /**
42      * A Shader that draws a sweep gradient around a center point.
43      *
44      * @param cx       The x-coordinate of the center
45      * @param cy       The y-coordinate of the center
46      * @param colors   The colors to be distributed between around the center.
47      *                 There must be at least 2 colors in the array.
48      * @param positions May be NULL. The relative position of
49      *                 each corresponding color in the colors array, beginning
50      *                 with 0 and ending with 1.0. If the values are not
51      *                 monotonic, the drawing may produce unexpected results.
52      *                 If positions is NULL, then the colors are automatically
53      *                 spaced evenly.
54      */
SweepGradient(float cx, float cy, @NonNull @ColorInt int colors[], @Nullable float positions[])55     public SweepGradient(float cx, float cy,
56             @NonNull @ColorInt int colors[], @Nullable float positions[]) {
57         if (colors.length < 2) {
58             throw new IllegalArgumentException("needs >= 2 number of colors");
59         }
60         if (positions != null && colors.length != positions.length) {
61             throw new IllegalArgumentException(
62                     "color and position arrays must be of equal length");
63         }
64         mType = TYPE_COLORS_AND_POSITIONS;
65         mCx = cx;
66         mCy = cy;
67         mColors = colors.clone();
68         mPositions = positions != null ? positions.clone() : null;
69     }
70 
71     /**
72      * A Shader that draws a sweep gradient around a center point.
73      *
74      * @param cx       The x-coordinate of the center
75      * @param cy       The y-coordinate of the center
76      * @param color0   The color to use at the start of the sweep
77      * @param color1   The color to use at the end of the sweep
78      */
SweepGradient(float cx, float cy, @ColorInt int color0, @ColorInt int color1)79     public SweepGradient(float cx, float cy, @ColorInt int color0, @ColorInt int color1) {
80         mType = TYPE_COLOR_START_AND_COLOR_END;
81         mCx = cx;
82         mCy = cy;
83         mColor0 = color0;
84         mColor1 = color1;
85         mColors = null;
86         mPositions = null;
87     }
88 
89     @Override
createNativeInstance(long nativeMatrix)90     long createNativeInstance(long nativeMatrix) {
91         if (mType == TYPE_COLORS_AND_POSITIONS) {
92             return nativeCreate1(nativeMatrix, mCx, mCy, mColors, mPositions);
93         } else { // TYPE_COLOR_START_AND_COLOR_END
94             return nativeCreate2(nativeMatrix, mCx, mCy, mColor0, mColor1);
95         }
96     }
97 
98     /**
99      * @hide
100      */
101     @Override
copy()102     protected Shader copy() {
103         final SweepGradient copy;
104         if (mType == TYPE_COLORS_AND_POSITIONS) {
105             copy = new SweepGradient(mCx, mCy, mColors.clone(),
106                     mPositions != null ? mPositions.clone() : null);
107         } else { // TYPE_COLOR_START_AND_COLOR_END
108             copy = new SweepGradient(mCx, mCy, mColor0, mColor1);
109         }
110         copyLocalMatrix(copy);
111         return copy;
112     }
113 
nativeCreate1(long matrix, float x, float y, int colors[], float positions[])114     private static native long nativeCreate1(long matrix, float x, float y,
115             int colors[], float positions[]);
nativeCreate2(long matrix, float x, float y, int color0, int color1)116     private static native long nativeCreate2(long matrix, float x, float y,
117             int color0, int color1);
118 }
119 
120