Question

I’m writing a composite view by overriding a ViewGroup, like so:

public class CompositeView extends RelativeLayout

I need to perform some one-time initialization after the measurements have been set (i.e. onMeasure has been called) because I need to know the height.

I was thinking of overriding onAttachedToWindow, but the docs mention that:

it may be called any time before the first onDraw — including before or after onMeasure(int, int).

What other options do I have?

Thanks

Answer 1

I prefer to use onSizeChanged in my CustomViews:

@Override
protected void onSizeChanged(final int w, final int h, final int oldw, final int oldh) {
    boolean changed = false;
    changed |= w != oldw;
    changed |= h != oldh;
    changed &= w > 0;
    changed &= h > 0;
    if (changed) {
            //do initialization stuff here
            ...

This method is called once after layouting is finished. This questions gives some extra details.