安卓开发中Bitmap源码实例:基于安卓开发浏览器实例 源码

安卓开发中Bitmap源码实例

package android.graphics;

import java.awt.image.BufferedImage;

import java.io.File;

import java.io.IOException;

import java.io.InputStream;

import javax.imageio.ImageIO;

public final class Bitmap extends _Original_Bitmap {

private BufferedImage mImage;

public Bitmap(File input) throws IOException {

super(1, true, null, -1);

mImage = ImageIO.read(input);

}

public Bitmap(InputStream is) throws IOException {

super(1, true, null, -1);

mImage = ImageIO.read(is);

}

Bitmap(BufferedImage image) {

super(1, true, null, -1);

mImage = image;

}

public BufferedImage getImage() {

return mImage;

}

// ----- overriden methods

public enum Config {

// these native values must match up with the enum in SkBitmap.h

ALPHA_8 (2),

RGB_565 (4),

ARGB_4444 (5),

ARGB_8888 (6);

Config(int ni) {

this.nativeInt = ni;

}

final int nativeInt;

/* package */ static Config nativeToConfig(int ni) {

return sConfigs[ni];

}

private static Config sConfigs[] = {

null, null, ALPHA_8, null, RGB_565, ARGB_4444, ARGB_8888

};

}

@Override

public int getWidth() {

return mImage.getWidth();

}

@Override

public int getHeight() {

return mImage.getHeight();

}

/**

* Returns an immutable bitmap from the source bitmap. The new bitmap may

* be the same object as source, or a copy may have been made.

*/

public static Bitmap createBitmap(Bitmap src) {

return createBitmap(src, 0, 0, src.getWidth(), src.getHeight(), null, false);

}

/**

* Returns an immutable bitmap from the specified subset of the source

* bitmap. The new bitmap may be the same object as source, or a copy may

* have been made.

*

* @param source The bitmap we are subsetting

* @param x The x coordinate of the first pixel in source

* @param y The y coordinate of the first pixel in source

* @param width The number of pixels in each row

* @param height The number of rows

*/

public static Bitmap createBitmap(Bitmap source, int x, int y,

int width, int height) {

return new Bitmap(source.mImage.getSubimage(x, y, width, height));

}

/**

* Returns an immutable bitmap from subset of the source bitmap,

* transformed by the optional matrix.

*

* @param source The bitmap we are subsetting

* @param x The x coordinate of the first pixel in source

* @param y The y coordinate of the first pixel in source

* @param width The number of pixels in each row

* @param height The number of rows

* @param m Option matrix to be applied to the pixels

* @param filter true if the source should be filtered.

* Only applies if the matrix contains more than just

* translation.

* @return A bitmap that represents the specified subset of source

* @throws IllegalArgumentException if the x, y, width, height values are

* outside of the dimensions of the source bitmap.

*/

public static Bitmap createBitmap(Bitmap source, int x, int y, int width,

int height, Matrix m, boolean filter) {

checkXYSign(x, y);

checkWidthHeight(width, height);

if (x + width > source.getWidth()) {

throw new IllegalArgumentException(

"x + width must be <= bitmap.width()");

}

if (y + height > source.getHeight()) {

throw new IllegalArgumentException(

"y + height must be <= bitmap.height()");

}

// check if we can just return our argument unchanged

if (!source.isMutable() && x == 0 && y == 0

&& width == source.getWidth() && height == source.getHeight()

&& (m == null || m.isIdentity())) {

return source;

}

if (m == null || m.isIdentity()) {

return new Bitmap(source.mImage.getSubimage(x, y, width, height));

}

int neww = width;

int newh = height;

Paint paint;

Rect srcR = new Rect(x, y, x + width, y + height);

RectF dstR = new RectF(0, 0, width, height);

/* the dst should have alpha if the src does, or if our matrix

doesn"t preserve rectness

*/

boolean hasAlpha = source.hasAlpha() || !m.rectStaysRect();

RectF deviceR = new RectF();

m.mapRect(deviceR, dstR);

neww = Math.round(deviceR.width());

newh = Math.round(deviceR.height());

Canvas canvas = new Canvas(neww, newh);

canvas.translate(-deviceR.left, -deviceR.top);

canvas.concat(m);

paint = new Paint();

paint.setFilterBitmap(filter);

if (!m.rectStaysRect()) {

paint.setAntiAlias(true);

}

canvas.drawBitmap(source, srcR, dstR, paint);

return new Bitmap(canvas.getImage());

}

/**

* Returns a mutable bitmap with the specified width and height.

*

* @param width The width of the bitmap

* @param height The height of the bitmap

* @param config The bitmap config to create.

* @throws IllegalArgumentException if the width or height are <= 0

*/

public static Bitmap createBitmap(int width, int height, Config config) {

return new Bitmap(new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB));

}

/**

* Returns a immutable bitmap with the specified width and height, with each

* pixel value set to the corresponding value in the colors array.

*

* @param colors Array of {@link Color} used to initialize the pixels.

* @param offset Number of values to skip before the first color in the

* array of colors.

* @param stride Number of colors in the array between rows (must be >=

* width or <= -width).

* @param width The width of the bitmap

* @param height The height of the bitmap

* @param config The bitmap config to create. If the config does not

* support per-pixel alpha (e.g. RGB_565), then the alpha

* bytes in the colors[] will be ignored (assumed to be FF)

* @throws IllegalArgumentException if the width or height are <= 0, or if

* the color array"s length is less than the number of pixels.

*/

public static Bitmap createBitmap(int colors[], int offset, int stride,

int width, int height, Config config) {

checkWidthHeight(width, height);

if (Math.abs(stride) < width) {

throw new IllegalArgumentException("abs(stride) must be >= width");

}

int lastScanline = offset + (height - 1) * stride;

int length = colors.length;

if (offset < 0 || (offset + width > length)

|| lastScanline < 0

|| (lastScanline + width > length)) {

throw new ArrayIndexOutOfBoundsException();

}

// TODO: create an immutable bitmap...

throw new UnsupportedOperationException();

}

/**

* Returns a immutable bitmap with the specified width and height, with each

* pixel value set to the corresponding value in the colors array.

*

* @param colors Array of {@link Color} used to initialize the pixels.

* This array must be at least as large as width * height.

* @param width The width of the bitmap

* @param height The height of the bitmap

* @param config The bitmap config to create. If the config does not

* support per-pixel alpha (e.g. RGB_565), then the alpha

* bytes in the colors[] will be ignored (assumed to be FF)

* @throws IllegalArgumentException if the width or height are <= 0, or if

* the color array"s length is less than the number of pixels.

*/

public static Bitmap createBitmap(int colors[], int width, int height,

Config config) {

return createBitmap(colors, 0, width, width, height, config);

}

public static Bitmap createScaledBitmap(Bitmap src, int dstWidth,

int dstHeight, boolean filter) {

Matrix m;

synchronized (Bitmap.class) {

// small pool of just 1 matrix

m = sScaleMatrix;

sScaleMatrix = null;

}

if (m == null) {

m = new Matrix();

}

final int width = src.getWidth();

final int height = src.getHeight();

final float sx = dstWidth / (float)width;

final float sy = dstHeight / (float)height;

m.setScale(sx, sy);

Bitmap b = Bitmap.createBitmap(src, 0, 0, width, height, m, filter);

synchronized (Bitmap.class) {

// do we need to check for null? why not just assign everytime?

if (sScaleMatrix == null) {

sScaleMatrix = m;

}

}

return b;

}

}