I want to inflate a layout, draw it onto a 96x96 bitmap, and send it to MetaWatch, whose 96x96 black-and-white screen has no gradations of gray. In fact, I have managed to do it, but I am not content with the result: the characters are either too large or too thin and unreadable.
If I render the view onto a 96x96 bitmap, I get very large letters on a tiny screen:
public void sendView(View v) {
Bitmap bm = createViewBitmap(v, 1, 1);
sendLcdBitmap(bm);
bm.recycle();
}
If I render the view onto a bigger bitmap and scale it back by calling sendViewScaled(R.layout.test_layout, 1, 4), the scaled text does not look good. That is, it could be smaller, but it will get too thin if I make it smaller.
public void sendViewScaled(View v, int num, int denom) {
Bitmap bm = createViewBitmap(v, num, denom);
Bitmap bm2 = Bitmap.createScaledBitmap(bm, SCREEN_SIZE, SCREEN_SIZE, false);
sendLcdBitmap(bm2);
bm2.recycle();
bm.recycle();
}
public void sendViewScaled(int id, int num, int denom) {
sendViewScaled(inflateView(id), num, denom);
}
The function to convert a view into a bitmap is:
protected Bitmap createViewBitmap(View v, int num, int denom) {
v.measure(MeasureSpec.makeMeasureSpec(SCREEN_SIZE*num/denom, MeasureSpec.EXACTLY)
,MeasureSpec.makeMeasureSpec(SCREEN_SIZE*num/denom, MeasureSpec.EXACTLY)
);
Bitmap b = Bitmap.createBitmap(v.getMeasuredWidth(), v.getMeasuredHeight(), Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(b);
c.setDensity(Bitmap.DENSITY_NONE);//DisplayMetrics.DENSITY_xxx;
v.layout(0, 0, v.getMeasuredWidth(), v.getMeasuredHeight());
v.draw(c);
return b;
}
The function sendLcdBitmap() converts the ARGB_8888 into a single-bit bitmap using the function:
protected boolean isRatherWhite(int color) {
return Color.red(color)+Color.green(color)+Color.blue(color) > 127*3;
//return color == Color.WHITE;
}
So, the question is:
I want to render a layout like R.layout.test_layout onto a 96x96 bitmap, B&W, no gradations of gray. How do I get a good quality?
Relevant questions:
Converting a view to Bitmap without displaying it in Android?
getMeasuredWidth returns totally wrong value
How to Resize a Bitmap in Android?
How to convert Views to bitmaps?
http://www.skoumal.net/en/android-how-draw-text-bitmap
UPDATE: playing with the value used in isRatherWhite() helped a bit.
