I figured out a way to do it. I override RelativeLayout, and get it to keep pointers to my upper and lower views. Then when it processes onMeasure, it sets the desired heights on my 2 views. They use the desired height when they handle onMeasure. This gives me one view at 2/3 of the visible area, with the other one below.
-- from my Layout class
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// set default screen heights
int heightSize = MeasureSpec.getSize(heightMeasureSpec);
if ( upper != null )
upper.setPrefHeight((heightSize*2)/3);
if ( lower != null )
lower.setPrefHeight(heightSize/3);
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
-- from the View derived classes
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
setMeasuredDimension(measureWidth(widthMeasureSpec),
measureHeight(heightMeasureSpec));
}
/**
* Determines the width of this view
* @param measureSpec A measureSpec packed into an int
* @return The width of the view, honoring constraints from measureSpec
*/
private int measureWidth(int measureSpec) {
int result = 0;
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
if (specMode == MeasureSpec.EXACTLY) {
// We were told how big to be
result = specSize;
} else {
DisplayMetrics dm = new DisplayMetrics();
((WindowManager)contxt.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay().getMetrics(dm);
result = dm.widthPixels;
}
width = result;
return result;
}
/**
* Determines the height of this view
* @param measureSpec A measureSpec packed into an int
* @return The height of the view, honoring constraints from measureSpec
*/
private int measureHeight(int measureSpec) {
int result = 0;
int specMode = MeasureSpec.getMode(measureSpec);
int specSize = MeasureSpec.getSize(measureSpec);
if (specMode == MeasureSpec.EXACTLY) {
// We were told how big to be
result = specSize;
} else {
result = prefHeight;
}
height = result;
return result;
}