DistributingLayout

DistributeLayout.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.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE. */

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


/**
 * A subclass of LineaLayout that distributes it's children evenly over it's entire width or height,
 * depending on the orientation
 * /
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);

        if (getChildCount() == 0) {
            return;
        }

        final int orientation = getOrientation();
        if (orientation == LinearLayout.HORIZONTAL) {
            final int availableWidth = getMeasuredWidth() - (getPaddingLeft() + getPaddingRight());
            int spacingSum = availableWidth;
            for (int i = 0, len = getChildCount(); i < len; i++) {
                spacingSum -= getChildAt(i).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;
            }
        }
        else {
            final int availableHeight = getMeasuredHeight() - (getPaddingTop() + getPaddingBottom());
            int spacingSum = availableHeight;
            for (int i = 0, len = getChildCount(); i < len; i++) {
                spacingSum -= getChildAt(i).getMeasuredHeight();
            }

            final int gridMarginBottom = spacingSum / (getChildCount() + 1);

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

Misc.md

#Changelog

###10.7.2014 0.1.0 use better algorithm than in initial version. Supports: Views of same width, horizontal orientation

###11.7.2014 0.2.0 Add support for vertical align Supports: Views of same width/height, horizontal/vertical orientation

###12.7.2014 0.2.0 Remove assumption that all children are of same size Supports: horizontal/vertical orientation