DistributingLayout.java

/* The MIT License (MIT)
 
Copyright (c) 2014, Marty Glaubitz
 
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.
 
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IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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THE SOFTWARE. */

import android.content.Context;
import android.util.AttributeSet;
import android.view.View;
import android.widget.LinearLayout;

public class DistributeLayout extends LinearLayout {

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

    public DistributeLayout(Context context, AttributeSet attrs) {
        super(context, attrs);
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);

        final int orientation = getOrientation();
        if (orientation == LinearLayout.HORIZONTAL && getChildCount() > 0) {
            final int availableWidth = getMeasuredWidth() - (getPaddingLeft() + getPaddingRight());
            final int spacingSum = availableWidth - getChildCount() * getChildAt(0).getMeasuredWidth();
            final int gridMarginLeft = spacingSum / (getChildCount() + 1);

            for (int i = 0, len = getChildCount(); i < len; i++) {
                final View childView = getChildAt(i);
                final MarginLayoutParams layoutParams = (MarginLayoutParams) childView.getLayoutParams();
                layoutParams.leftMargin = gridMarginLeft;
            }
        }
    }
}

TODO.md

#TODO

1. remove assumption that all children are of the same size

i added support for orientation vertical - you might update your version ;)