Android example source code file (BitmapTest.java)

This example Android source code file (BitmapTest.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Android by Example" ^TM.

Java - Android tags/keywords

android, bitmap, bitmaptest, drawing, exception, graphics, illegalstateexception, paint, smalltest, test, testcase, ui

The BitmapTest.java Android example source code

/*
 * Copyright (C) 2006 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.graphics;

import android.graphics.Bitmap;
import android.graphics.Color;
import android.test.suitebuilder.annotation.SmallTest;
import junit.framework.TestCase;


public class BitmapTest extends TestCase {

    @SmallTest
    public void testBasic() throws Exception {
        Bitmap bm1 = Bitmap.createBitmap(100, 200, Bitmap.Config.ARGB_8888);
        Bitmap bm2 = Bitmap.createBitmap(100, 200, Bitmap.Config.RGB_565);
        Bitmap bm3 = Bitmap.createBitmap(100, 200, Bitmap.Config.ARGB_4444);

        assertTrue("mutability", bm1.isMutable());
        assertTrue("mutability", bm2.isMutable());
        assertTrue("mutability", bm3.isMutable());

        assertEquals("width", 100, bm1.getWidth());
        assertEquals("width", 100, bm2.getWidth());
        assertEquals("width", 100, bm3.getWidth());

        assertEquals("rowbytes", 400, bm1.getRowBytes());
        assertEquals("rowbytes", 200, bm2.getRowBytes());
        assertEquals("rowbytes", 200, bm3.getRowBytes());
        
        assertEquals("height", 200, bm1.getHeight());
        assertEquals("height", 200, bm2.getHeight());
        assertEquals("height", 200, bm3.getHeight());

        assertTrue("hasAlpha", bm1.hasAlpha());
        assertFalse("hasAlpha", bm2.hasAlpha());
        assertTrue("hasAlpha", bm3.hasAlpha());
        
        assertTrue("getConfig", bm1.getConfig() == Bitmap.Config.ARGB_8888);
        assertTrue("getConfig", bm2.getConfig() == Bitmap.Config.RGB_565);
        assertTrue("getConfig", bm3.getConfig() == Bitmap.Config.ARGB_4444);
    }

    @SmallTest
    public void testMutability() throws Exception {
        Bitmap bm1 = Bitmap.createBitmap(100, 200, Bitmap.Config.ARGB_8888);
        Bitmap bm2 = Bitmap.createBitmap(new int[100 * 200], 100, 200,
                                         Bitmap.Config.ARGB_8888);

        assertTrue("mutability", bm1.isMutable());
        assertFalse("mutability", bm2.isMutable());

        bm1.eraseColor(0);

        try {
            bm2.eraseColor(0);
            fail("eraseColor should throw exception");
        } catch (IllegalStateException ex) {
            // safe to catch and ignore this
        }
    }

    @SmallTest
    public void testGetPixelsWithAlpha() throws Exception {
        int[] colors = new int[100];
        for (int i = 0; i < 100; i++) {
            colors[i] = (0xFF << 24) | (i << 16) | (i << 8) | i;
        }

        Bitmap bm = Bitmap.createBitmap(colors, 10, 10,
                                        Bitmap.Config.ARGB_8888);

        int[] pixels = new int[100];
        bm.getPixels(pixels, 0, 10, 0, 0, 10, 10);
        for (int i = 0; i < 100; i++) {
            int p = bm.getPixel(i % 10, i / 10);
            assertEquals("getPixels", p, pixels[i]);
        }

        for (int i = 0; i < 100; i++) {
            int p = bm.getPixel(i % 10, i / 10);
            assertEquals("getPixel", p, colors[i]);
            assertEquals("pixel value", p,
                         ((0xFF << 24) | (i << 16) | (i << 8) | i));
        }

    }

    @SmallTest
    public void testGetPixelsWithoutAlpha() throws Exception {
        int[] colors = new int[100];
        for (int i = 0; i < 100; i++) {
            colors[i] = (0xFF << 24) | (i << 16) | (i << 8) | i;
        }

        Bitmap bm = Bitmap.createBitmap(colors, 10, 10, Bitmap.Config.RGB_565);

        int[] pixels = new int[100];
        bm.getPixels(pixels, 0, 10, 0, 0, 10, 10);
        for (int i = 0; i < 100; i++) {
            int p = bm.getPixel(i % 10, i / 10);
            assertEquals("getPixels", p, pixels[i]);
        }
    }

    @SmallTest
    public void testSetPixelsWithAlpha() throws Exception {
        int[] colors = new int[100];
        for (int i = 0; i < 100; i++) {
            colors[i] = (0xFF << 24) | (i << 16) | (i << 8) | i;
        }

        Bitmap.Config config = Bitmap.Config.ARGB_8888;
        Bitmap bm1 = Bitmap.createBitmap(colors, 10, 10, config);
        Bitmap bm2 = Bitmap.createBitmap(10, 10, config);

        for (int i = 0; i < 100; i++) {
            bm2.setPixel(i % 10, i / 10, colors[i]);
        }

        for (int i = 0; i < 100; i++) {
            assertEquals("setPixel",
                    bm1.getPixel(i % 10, i / 10), bm2.getPixel(i % 10, i / 10));
        }

        for (int i = 0; i < 100; i++) {
            assertEquals("setPixel value",
                         bm1.getPixel(i % 10, i / 10), colors[i]);
        }
    }

    @SmallTest
    public void testSetPixelsWithoutAlpha() throws Exception {
        int[] colors = new int[100];
        for (int i = 0; i < 100; i++) {
            colors[i] = (0xFF << 24) | (i << 16) | (i << 8) | i;
        }

        Bitmap.Config config = Bitmap.Config.RGB_565;
        Bitmap bm1 = Bitmap.createBitmap(colors, 10, 10, config);
        Bitmap bm2 = Bitmap.createBitmap(10, 10, config);

        for (int i = 0; i < 100; i++) {
            bm2.setPixel(i % 10, i / 10, colors[i]);
        }

        for (int i = 0; i < 100; i++) {
            assertEquals("setPixel", bm1.getPixel(i % 10, i / 10),
                         bm2.getPixel(i % 10, i / 10));
        }
    }

    private static int computePrePostMul(int alpha, int comp) {
        if (alpha == 0) {
            return 0;
        }
        int premul = Math.round(alpha * comp / 255.f);
        int unpre = Math.round(255.0f * premul / alpha);
        return unpre;
    }

    @SmallTest
    public void testSetPixelsWithNonOpaqueAlpha() throws Exception {
        int[] colors = new int[256];
        for (int i = 0; i < 256; i++) {
            colors[i] = (i << 24) | (0xFF << 16) | (0x80 << 8) | 0;
        }
        
        Bitmap.Config config = Bitmap.Config.ARGB_8888;

        // create a bitmap with the color array specified
        Bitmap bm1 = Bitmap.createBitmap(colors, 16, 16, config);
        
        // create a bitmap with no colors, but then call setPixels
        Bitmap bm2 = Bitmap.createBitmap(16, 16, config);
        bm2.setPixels(colors, 0, 16, 0, 0, 16, 16);

        // now check that we did a good job returning the unpremultiplied alpha
        final int tolerance = 1;
        for (int i = 0; i < 256; i++) {
            int c0 = colors[i];
            int c1 = bm1.getPixel(i % 16, i / 16);
            int c2 = bm2.getPixel(i % 16, i / 16);
            
            // these two should always be identical
            assertEquals("getPixel", c1, c2);
            
            // comparing the original (c0) with the returned color is tricky,
            // since it gets premultiplied during the set(), and unpremultiplied
            // by the get().
            int a0 = Color.alpha(c0);
            int a1 = Color.alpha(c1);
            assertEquals("alpha", a0, a1);
            
            int r0 = Color.red(c0);
            int r1 = Color.red(c1);
            int rr = computePrePostMul(a0, r0);
            assertTrue("red", Math.abs(rr - r1) <= tolerance);
            
            int g0 = Color.green(c0);
            int g1 = Color.green(c1);
            int gg = computePrePostMul(a0, g0);
            assertTrue("green", Math.abs(gg - g1) <= tolerance);
            
            int b0 = Color.blue(c0);
            int b1 = Color.blue(c1);
            int bb = computePrePostMul(a0, b0);
            assertTrue("blue", Math.abs(bb - b1) <= tolerance);
            
            if (false) {
                int cc = Color.argb(a0, rr, gg, bb);
                android.util.Log.d("skia", "original " + Integer.toHexString(c0) +
                                " set+get " + Integer.toHexString(c1) +
                               " local " + Integer.toHexString(cc));
            }
        }
    }
}