U can't set the width, but you can use a custom rating bar, just add:
compile 'FlexibleRatingBar:flexibleratingbar:1.3'
This rating panel will automatically fit. Then you initialize, for example:
ratingBar = new FlexibleRatingBar(this); ratingBar.setStepSize(1); ratingBar.setColorFillOn(Color.rgb(65,105,225)); ratingBar.setColorFillPressedOn(Color.rgb(135,206,235)); someLayout.addView(ratingBar);
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