protected override void onDraw (Canvas canvas)
{
canvas.drawColor (Color.WHITE);
Paint labelP = new Paint (Paint.ANTI_ALIAS_FLAG);
labelP.setTextAlign (Paint.Align.CENTER);
Paint paint = new Paint ();
paint.setFilterBitmap (false);
canvas.translate (15, 35);
int x = 0;
int y = 0;
for (int i = 0; i < sModes.Length; i++) {
// draw the border
paint.setStyle (Paint.Style.STROKE);
paint.setShader (null);
canvas.drawRect (x - 0.5f, y - 0.5f,
x + W + 0.5f, y + H + 0.5f, paint);
// draw the checker-board pattern
paint.setStyle (Paint.Style.FILL);
paint.setShader (mBG);
canvas.drawRect (x, y, x + W, y + H, paint);
// draw the src/dst example into our offscreen bitmap
int sc = canvas.saveLayer (x, y, x + W, y + H, null,
Canvas.MATRIX_SAVE_FLAG |
Canvas.CLIP_SAVE_FLAG |
Canvas.HAS_ALPHA_LAYER_SAVE_FLAG |
Canvas.FULL_COLOR_LAYER_SAVE_FLAG |
Canvas.CLIP_TO_LAYER_SAVE_FLAG);
canvas.translate (x, y);
canvas.drawBitmap (mDstB, 0, 0, paint);
paint.setXfermode (sModes [i]);
canvas.drawBitmap (mSrcB, 0, 0, paint);
paint.setXfermode (null);
canvas.restoreToCount (sc);
// draw the label
canvas.drawText (sLabels [i],
x + W / 2, y - labelP.getTextSize () / 2, labelP);
x += W + 10;
// wrap around when we've drawn enough for one row
if ((i % ROW_MAX) == ROW_MAX - 1) {
x = 0;
y += H + 30;
}
}
}