Fill up the empty space of a FlowLayout on Android

Question

I'm creating an app which has a flow layout. The FlowLayout implementation I found from the web (I don't remember exactly from where). Now, when my layout width greater than sum of the widths of its children, I need to fill the empty space, giving to each the proper width. I tried to give them MATCH_PARENT as width, but it didn't worked and each element was created from the "new line".
Please help me to solve my problem. Thanks in advance.

Here is a FlowLayout class implementation, which I use:

public class FlowLayout extends ViewGroup {
public static final String TAG = FlowLayout.class.getSimpleName();

private int mHorizontalSpacing = 10;
private int mVerticalSpacing = 10;

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

public FlowLayout(Context context, AttributeSet attrs) {
    super(context, 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);
    } finally {
        a.recycle();
    }
}

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

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

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

    boolean breakLine = false;

    final int count = getChildCount();

    Log.d(TAG, "child count = " + count);

    for (int i = 0; i < count; i++) {
        View child = getChildAt(i);
        LayoutParams lp = (LayoutParams) child.getLayoutParams();
        measureChild(child, widthMeasureSpec, heightMeasureSpec);

        Log.d(TAG, "child " + i + " mw=" + child.getMeasuredWidth() + " mh=" + child.getMeasuredHeight());

        if (breakLine || currentWidth + child.getMeasuredWidth() > widthSize) {
            height += currentHeight + mVerticalSpacing;
            currentHeight = 0;
            if (currentWidth > width) width = currentWidth;
            currentWidth = getPaddingLeft();
        }

        int spacing = mHorizontalSpacing;
        if (lp.spacing != Integer.MAX_VALUE) {
            spacing = lp.spacing;
        }

        lp.x = currentWidth;
        lp.y = height;

        Log.d(TAG, "child " + i + " x=" + lp.x + " y=" + lp.y);

        currentWidth += child.getMeasuredWidth() + spacing;
        int childHeight = child.getMeasuredHeight();
        if (childHeight > currentHeight) currentHeight = childHeight;

        breakLine = lp.breakLine;
    }

    // after last row (patched by yuku)
    {
        height += currentHeight;
        if (currentWidth > width) width = currentWidth;
    }

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

    Log.d(TAG, "onMeasure w=" + width + " h=" + height + " widthMeasureSpec=" + Integer.toHexString(widthMeasureSpec) + " heightMeasureSpec=" + Integer.toHexString(heightMeasureSpec));

    // don't resolve height (patched by yuku)
    setMeasuredDimension(resolveSize(width, widthMeasureSpec), resolveSize(height, heightMeasureSpec));
}

@Override protected void onLayout(boolean changed, int l, int t, int r, int b) {
    final int count = getChildCount();
    for (int i = 0; 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 public LayoutParams generateDefaultLayoutParams() {
    return new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
}

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

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

public static class LayoutParams extends ViewGroup.LayoutParams {
    public boolean breakLine;
    public int spacing = Integer.MAX_VALUE;

    private int x;
    private int y;

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

    public LayoutParams(Context context, AttributeSet attrs) {
        super(context, attrs);

        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.FlowLayout_LayoutParams);
        try {
            spacing = a.getDimensionPixelSize(R.styleable.FlowLayout_LayoutParams_layout_spacing, Integer.MAX_VALUE);
            breakLine = a.getBoolean(R.styleable.FlowLayout_LayoutParams_layout_breakLine, false);
        } finally {
            a.recycle();
        }       
    }
}
}

I want to achieve this effect:

instead of this:

Answer 1

I think I got it, it's a bit tricky, but here's more or less what you need to do. In your original for loop, keep track of whether or not you've gone to a new line. Let's say you call this variable isOneLine and initialize it to true, set it to false as soon as you reset currentWidth to 0. Then, outside of your for loop:

if (isOneLine) {
  //There's always N + 1 padding "spaces"
  int paddingBetween = (widthSize - currentWidth)/(count + 1); 

  for (int i = 0; i < count; i++) {
    View child = getChildAt(i);
    LayoutParams lp = (LayoutParams) child.getLayoutParams();
    measureChild(child, widthMeasureSpec, heightMeasureSpec);

    int spacing = mHorizontalSpacing;
    if (lp.spacing != Integer.MAX_VALUE) {
        spacing = lp.spacing;
    }
    //Not sure exactly what spacing is here, but I assume you have to take it into account somewhere...
    lp.x = paddingBetween + currentWidth;
    lp.y = 0;

    currentWidth += child.getMeasuredWidth() + spacing + paddingBetween;
  }
}