Authorative way to override onMeasure()?

Question

What\'s the correct way of overriding onMeasure()? I\'ve seen various approaches. For example, Professional Android Development uses MeasureSpec to calculate the di

Answer 1

you can take this piece of code as an example of onMeasure()::

public class MyLayerLayout extends RelativeLayout {

    public MyLayerLayout(Context context) {
        super(context);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int parentWidth = MeasureSpec.getSize(widthMeasureSpec);
        int parentHeight = MeasureSpec.getSize(heightMeasureSpec);

        int currentChildCount = getChildCount();
        for (int i = 0; i < currentChildCount; i++) {
            View currentChild = getChildAt(i);

            //code to find information

            int widthPercent = currentChildInfo.getWidth();
            int heightPercent = currentChildInfo.getHeight();

//considering we will pass height & width as percentage

            int myWidth = (int) Math.round(parentWidth * (widthPercent / 100.0));
            int myHeight = (int) Math.round(parentHeight * (heightPercent / 100.0));

//Considering we need to set horizontal & vertical position of the view in parent

            AlignmentTraitValue vAlign = currentChildInfo.getVerticalLocation() != null ? currentChildlayerInfo.getVerticalLocation() : currentChildAlignmentTraitValue.TOP;
            AlignmentTraitValue hAlign = currentChildInfo.getHorizontalLocation() != null ? currentChildlayerInfo.getHorizontalLocation() : currentChildAlignmentTraitValue.LEFT;
            int topPadding = 0;
            int leftPadding = 0;

            if (vAlign.equals(currentChildAlignmentTraitValue.CENTER)) {
                topPadding = (parentHeight - myHeight) / 2;
            } else if (vAlign.equals(currentChildAlignmentTraitValue.BOTTOM)) {
                topPadding = parentHeight - myHeight;
            }

            if (hAlign.equals(currentChildAlignmentTraitValue.CENTER)) {
                leftPadding = (parentWidth - myWidth) / 2;
            } else if (hAlign.equals(currentChildAlignmentTraitValue.RIGHT)) {
                leftPadding = parentWidth - myWidth;
            }
            LayoutParams myLayoutParams = new LayoutParams(myWidth, myHeight);
            currentChildLayoutParams.setMargins(leftPadding, topPadding, 0, 0);
            currentChild.setLayoutParams(myLayoutParams);
        }
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }
}