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      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 /**
     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  */
     25 public 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