ColorMatrixColorFilter.java revision f559326b182e321f51ab9711614d3e37fefa603a 
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
19/**
20 * A color filter that transforms colors through a 4x5 color matrix. This filter
21 * can be used to change the saturation of pixels, convert from YUV to RGB, etc.
22 *
23 * @see ColorMatrix
24 */
25public class ColorMatrixColorFilter extends ColorFilter {
26    private final ColorMatrix mMatrix = new ColorMatrix();
27
28    /**
29     * Create a color filter that transforms colors through a 4x5 color matrix.
30     *
31     * @param matrix 4x5 matrix used to transform colors. It is copied into
32     *               the filter, so changes made to the matrix after the filter
33     *               is constructed will not be reflected in the filter.
34     */
35    public ColorMatrixColorFilter(ColorMatrix matrix) {
36        mMatrix.set(matrix);
37        update();
38    }
39
40    /**
41     * Create a color filter that transforms colors through a 4x5 color matrix.
42     *
43     * @param array Array of floats used to transform colors, treated as a 4x5
44     *              matrix. The first 20 entries of the array are copied into
45     *              the filter. See ColorMatrix.
46     */
47    public ColorMatrixColorFilter(float[] array) {
48        if (array.length < 20) {
49            throw new ArrayIndexOutOfBoundsException();
50        }
51        mMatrix.set(array);
52        update();
53    }
54
55    /**
56     * Returns the {@link ColorMatrix} used by this filter. The returned
57     * value is never null. Modifying the returned matrix does not have
58     * any effect until you call {@link #setColorMatrix(ColorMatrix)}.
59     *
60     * @see #setColorMatrix(ColorMatrix)
61     *
62     * @hide
63     */
64    public ColorMatrix getColorMatrix() {
65        return mMatrix;
66    }
67
68    /**
69     * Specifies the color matrix used by this filter. If the specified
70     * color matrix is null, this filter's color matrix will be reset to
71     * the identity matrix.
72     *
73     * @param matrix A {@link ColorMatrix} or null
74     *
75     * @see #getColorMatrix()
76     * @see android.graphics.ColorMatrix#reset()
77     * @see #setColorMatrix(float[])
78     *
79     * @hide
80     */
81    public void setColorMatrix(ColorMatrix matrix) {
82        if (matrix == null) {
83            mMatrix.reset();
84        } else if (matrix != mMatrix) {
85            mMatrix.set(matrix);
86        }
87        update();
88    }
89
90    /**
91     * Specifies the color matrix used by this filter. If the specified
92     * color matrix is null, this filter's color matrix will be reset to
93     * the identity matrix.
94     *
95     * @param array Array of floats used to transform colors, treated as a 4x5
96     *              matrix. The first 20 entries of the array are copied into
97     *              the filter. See {@link ColorMatrix}.
98     *
99     * @see #getColorMatrix()
100     * @see android.graphics.ColorMatrix#reset()
101     * @see #setColorMatrix(ColorMatrix)
102     *
103     * @throws ArrayIndexOutOfBoundsException if the specified array's
104     *         length is < 20
105     *
106     * @hide
107     */
108    public void setColorMatrix(float[] array) {
109        if (array == null) {
110            mMatrix.reset();
111        } else {
112            if (array.length < 20) {
113                throw new ArrayIndexOutOfBoundsException();
114            }
115
116            mMatrix.set(array);
117        }
118        update();
119    }
120
121    private void update() {
122        final float[] colorMatrix = mMatrix.getArray();
123        destroyFilter(native_instance);
124        native_instance = nativeColorMatrixFilter(colorMatrix);
125    }
126
127    private static native long nativeColorMatrixFilter(float[] array);
128}
129