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
17package android.graphics;
18
19public class SweepGradient 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 mCx;
31    private float mCy;
32    private int[] mColors;
33    private float[] mPositions;
34    private int mColor0;
35    private int mColor1;
36
37    /**
38     * A subclass of Shader that draws a sweep gradient around a center point.
39     *
40     * @param cx       The x-coordinate of the center
41     * @param cy       The y-coordinate of the center
42     * @param colors   The colors to be distributed between around the center.
43     *                 There must be at least 2 colors in the array.
44     * @param positions May be NULL. The relative position of
45     *                 each corresponding color in the colors array, beginning
46     *                 with 0 and ending with 1.0. If the values are not
47     *                 monotonic, the drawing may produce unexpected results.
48     *                 If positions is NULL, then the colors are automatically
49     *                 spaced evenly.
50     */
51    public SweepGradient(float cx, float cy,
52                         int colors[], float positions[]) {
53        if (colors.length < 2) {
54            throw new IllegalArgumentException("needs >= 2 number of colors");
55        }
56        if (positions != null && colors.length != positions.length) {
57            throw new IllegalArgumentException(
58                        "color and position arrays must be of equal length");
59        }
60        mType = TYPE_COLORS_AND_POSITIONS;
61        mCx = cx;
62        mCy = cy;
63        mColors = colors;
64        mPositions = positions;
65        native_instance = nativeCreate1(cx, cy, colors, positions);
66        native_shader = nativePostCreate1(native_instance, cx, cy, colors, positions);
67    }
68
69    /**
70     * A subclass of Shader that draws a sweep gradient around a center point.
71     *
72     * @param cx       The x-coordinate of the center
73     * @param cy       The y-coordinate of the center
74     * @param color0   The color to use at the start of the sweep
75     * @param color1   The color to use at the end of the sweep
76     */
77    public SweepGradient(float cx, float cy, int color0, int color1) {
78        mType = TYPE_COLOR_START_AND_COLOR_END;
79        mCx = cx;
80        mCy = cy;
81        mColor0 = color0;
82        mColor1 = color1;
83        native_instance = nativeCreate2(cx, cy, color0, color1);
84        native_shader = nativePostCreate2(native_instance, cx, cy, color0, color1);
85    }
86
87    /**
88     * @hide
89     */
90    @Override
91    protected Shader copy() {
92        final SweepGradient copy;
93        switch (mType) {
94            case TYPE_COLORS_AND_POSITIONS:
95                copy = new SweepGradient(mCx, mCy, mColors.clone(),
96                        mPositions != null ? mPositions.clone() : null);
97                break;
98            case TYPE_COLOR_START_AND_COLOR_END:
99                copy = new SweepGradient(mCx, mCy, mColor0, mColor1);
100                break;
101            default:
102                throw new IllegalArgumentException("SweepGradient should be created with either " +
103                        "colors and positions or start color and end color");
104        }
105        copyLocalMatrix(copy);
106        return copy;
107    }
108
109    private static native int nativeCreate1(float x, float y, int colors[], float positions[]);
110    private static native int nativeCreate2(float x, float y, int color0, int color1);
111
112    private static native int nativePostCreate1(int native_shader, float cx, float cy,
113            int[] colors, float[] positions);
114    private static native int nativePostCreate2(int native_shader, float cx, float cy,
115            int color0, int color1);
116}
117
118