Question

I’ve written a custom view where I draw myself. I need this because I have to draw circles with borders where as this borders and some stuff within.

At the moment I use 5px as width of the circle borders. This looks OK on ldpi screens, good on mdpi screens and I think it’ll looks crappy on hdpi screens.

How should I write the view to scale the border for different screens? At the moment the custom view gets a attribute which sets the width in pixel.

How can I use other dimensions in the drawing process?

Answer 1

Think in dp, instead of pixel, and obtain pixel corresponding to a dp value using the following code:

/**
 * Convert a dimension in dip to px
 * @param dip
 * @param context
 * @return px
 */
public static int dipToPx(int dip, Context context) {
    return (int) (dip * context.getResources().getDisplayMetrics().density);
}

Or, if you have defined a dimension in an xml resource file, like this one:

<resources>
    <dimen name="common_padding_large">20dp</dimen>
</resources>

you can obtain pixel value of this dimension with

getContext().getResources().getDimension(R.dimen.common_padding_large);