rendering a TextView in a Bitmap for an android widget
- by foke
I'm building a widget which displays some text. By widget I mean the kind which lies on the desktop.
The problem is that I want to change text's font at runtime. There is several textview I would like, at runtime, to set the first as bold, the second blue and italic for example, etc.
I came up with this :
TextView tv = new TextView(context);
tv.setText(stringToDisplay);
tv.setTextColor(0xa00050ff); // example
tv.setTextSize(30); // example
Bitmap b = loadBitmapFromView(tv);
updateViews.setImageViewBitmap(R.id.id_of_the_imageview, b);
with
private static Bitmap loadBitmapFromView(View v)
{
Bitmap b = Bitmap.createBitmap(v.getLayoutParams().width, v.getLayoutParams().height, Bitmap.Config.ARGB_8888);
Canvas c = new Canvas(b);
v.layout(0, 0, v.getLayoutParams().width, v.getLayoutParams().height);
v.draw(c);
return b;
}
but it wont work (NullPointerException on first line of loadBitmap), until I replace v.getLayoutParams().width, v.getLayoutParams().height by fixed sizes like 250, 50
Bitmap b = Bitmap.createBitmap(250, 50, Bitmap.Config.ARGB_8888);
// ...
v.layout(0, 0, 250, 50);
But that's not a good solution ...
so I tried this :
LayoutInflater li = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View row = li.inflate(R.layout.widget_text, null);
TextView tv = (TextView) row.findViewById(R.id.id_of_the_textview);
widget_text being a layout similar to the displayed one but with TextViews instead of ImageViews, in the hope to get some size information out of it ..
but it's not working and I get this exception :
01-02 17:35:06.001: ERROR/AndroidRuntime(11025): Caused by: java.lang.IllegalArgumentException: width and height must be > 0
on the call to Bitmap.createBitmap()
so, someone could point me in the right direction?
