FlowLayout

attrs.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <declare-styleable name="FlowLayout">
        <attr name="verticalSpacing" format="dimension"/>
        <attr name="horizontalSpacing" format="dimension"/>
        <attr name="fillSpace" format="boolean"/>
    </declare-styleable>
</resources>

FlowLayout.java

package com.comalia.gesicamobile.manager.widget;

import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.view.View;
import android.view.ViewGroup;

import com.comalia.gesicamobile.manager.R;

import java.util.ArrayList;

public class FlowLayout extends ViewGroup {

    private int mHorizontalSpacing;
    private int mVerticalSpacing;
    private boolean mFillSpace;


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

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

    private void readAttrs(Context context, AttributeSet attrs) {
        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.FlowLayout);
        try {
            mHorizontalSpacing = a.getDimensionPixelSize(R.styleable.FlowLayout_horizontalSpacing, 0);
            mVerticalSpacing = a.getDimensionPixelSize(R.styleable.FlowLayout_verticalSpacing, 0);
            mFillSpace = a.getBoolean(R.styleable.FlowLayout_fillSpace, true);
        } finally {
            a.recycle();
        }
    }

    @Override
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
        int widthSize = MeasureSpec.getSize(widthMeasureSpec);
        int widthMode = MeasureSpec.getMode(widthMeasureSpec);

        int width = 0;
        int height = getPaddingTop();

        int currentWidth = getPaddingLeft();
        int currentHeight = 0;

        int count = getChildCount();

        // store how the child will be arranged in lines
        ArrayList<ArrayList<View>> lines = new ArrayList<ArrayList<View>>();
        ArrayList<View> line = new ArrayList<View>();
        lines.add(line);

        for (int i = 0; i < count; i++) {
            View child = getChildAt(i);
            if (child.getVisibility() == GONE) {
                continue;
            }

            measureChild(child, widthMeasureSpec, heightMeasureSpec);

            boolean newline = currentWidth + child.getMeasuredWidth() + getPaddingRight() > widthSize;
            if (newline) {
                height += currentHeight + mVerticalSpacing;
                currentHeight = 0;
                width = Math.max(width, currentWidth - mHorizontalSpacing);
                currentWidth = getPaddingLeft();

                line = new ArrayList<View>();
                lines.add(line);
            }
            line.add(child);

            LayoutParams lp = (LayoutParams) child.getLayoutParams();
            lp.x = currentWidth;
            lp.y = height;

            currentWidth += child.getMeasuredWidth() + mHorizontalSpacing;
            currentHeight = Math.max(currentHeight, child.getMeasuredHeight());
        }

        height += currentHeight;
        width = Math.max(width, currentWidth - mHorizontalSpacing);

        width += getPaddingRight();
        height += getPaddingBottom();

        setMeasuredDimension(resolveSize(width, widthMeasureSpec), resolveSize(height, heightMeasureSpec));

        if (mFillSpace) {
            // loop on lines and rearrange child measures to fit available space
            int widthPadded = widthSize - getPaddingLeft() - getPaddingRight();
            for (ArrayList<View> l : lines) {
                // get the max height and available width
                int maxHeight = 0, lineWidth = 0;
                for (View child : l) {
                    if (child.getMeasuredHeight() > maxHeight) {
                        maxHeight = child.getMeasuredHeight();
                    }
                    lineWidth += child.getMeasuredWidth();
                }
                int availableWidth = (widthPadded - lineWidth - (mHorizontalSpacing * (l.size() - 1))) / l.size();


                // redefine child size
                int xShift = 0;
                for (View child : l) {
                    int w = child.getMeasuredWidth() + availableWidth;
                    int wSpec = MeasureSpec.makeMeasureSpec(w, MeasureSpec.EXACTLY);
                    int hSpec = MeasureSpec.makeMeasureSpec(maxHeight, MeasureSpec.EXACTLY);
                    ((LayoutParams) child.getLayoutParams()).x += xShift;
                    child.measure(wSpec, hSpec);
                    xShift += availableWidth;
                }

            }
        }
    }

    @Override
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        for (int i = 0, count = getChildCount(); i < count; i++) {
            View child = getChildAt(i);
            LayoutParams lp = (LayoutParams) child.getLayoutParams();
            child.layout(lp.x, lp.y, lp.x + child.getMeasuredWidth(), lp.y + child.getMeasuredHeight());
        }
    }

    @Override
    protected boolean checkLayoutParams(ViewGroup.LayoutParams p) {
        return p instanceof LayoutParams;
    }

    @Override
    protected ViewGroup.LayoutParams generateDefaultLayoutParams() {
        return new ViewGroup.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
    }

    @Override
    public ViewGroup.LayoutParams generateLayoutParams(AttributeSet attrs) {
        return new LayoutParams(getContext(), attrs);
    }

    @Override
    protected ViewGroup.LayoutParams generateLayoutParams(ViewGroup.LayoutParams p) {
        return new LayoutParams(p.width, p.height);
    }

    public static class LayoutParams extends ViewGroup.LayoutParams {
        private int x, y;

        public LayoutParams(Context c, AttributeSet attrs) {
            super(c, attrs);
        }

        public LayoutParams(int width, int height) {
            super(width, height);
        }
    }
}