/**
* Returns a bitmap suitable for the all apps view. The bitmap will be a power
* of two sized ARGB_8888 bitmap that can be used as a gl texture.
*/
private Bitmap createIconBitmap(Drawable icon) {
int width = mIconWidth;
int height = mIconHeight;
if (icon instanceof PaintDrawable) {
PaintDrawable painter = (PaintDrawable) icon;
painter.setIntrinsicWidth(width);
painter.setIntrinsicHeight(height);
} else if (icon instanceof BitmapDrawable) {
// Ensure the bitmap has a density.
BitmapDrawable bitmapDrawable = (BitmapDrawable) icon;
Bitmap bitmap = bitmapDrawable.getBitmap();
if (bitmap.getDensity() == Bitmap.DENSITY_NONE) {
bitmapDrawable.setTargetDensity(mDisplayMetrics);
}
}
int sourceWidth = icon.getIntrinsicWidth();
int sourceHeight = icon.getIntrinsicHeight();
调节大的图片，使它按比例适合我们的画布
if (sourceWidth > 0 && sourceWidth > 0) {
// There are intrinsic sizes.
// if (width < sourceWidth || height < sourceHeight) {
// It's too big, scale it down.
final float ratio = (float) sourceWidth / sourceHeight;
if (sourceWidth > sourceHeight) {
height = (int) (width / ratio);
} else if (sourceHeight > sourceWidth) {
width = (int) (height * ratio);
}
这里是调节小的图片，如果给的图片小于画布，我们便使用原图的尺寸
// } else if (sourceWidth < width && sourceHeight < height) {
// // It's small, use the size they gave us.
// width = sourceWidth;
// height = sourceHeight;
// }
}
// no intrinsic size --> use default size
int textureWidth = mIconTextureWidth;
int textureHeight = mIconTextureHeight;
final Bitmap bitmap = Bitmap.createBitmap(textureWidth, textureHeight,
Bitmap.Config.ARGB_8888);
final Canvas canvas = mCanvas;
canvas.setBitmap(bitmap);
final int left = (textureWidth-width) / 2;
final int top = (textureHeight-height) / 2;
if (false) {
// draw a big box for the icon for debugging
canvas.drawColor(sColors[mColorIndex]);
if (++mColorIndex >= sColors.length) mColorIndex = 0;
Paint debugPaint = new Paint();
debugPaint.setColor(0xffcccc00);
canvas.drawRect(left, top, left+width, top+height, debugPaint);
}
mOldBounds.set(icon.getBounds());
icon.setBounds(left, top, left+width, top+height);
icon.draw(canvas);
icon.setBounds(mOldBounds);
return bitmap;
}