Checkable layout

CheckableLinearLayout.java

public class CheckableLinearLayout extends LinearLayout implements Checkable {
    private static final int[] CHECKED_STATE_SET = { android.R.attr.state_checked };
    private boolean mChecked;
    private OnCheckedChangeListener mOnCheckedChangeListener;

    public CheckableLinearLayout(Context context) {
        super(context, null);
    }

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

    public CheckableLinearLayout(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
    }

    public void setOnCheckedChangeListener(OnCheckedChangeListener onCheckedChangeListener) {
        mOnCheckedChangeListener = onCheckedChangeListener;
    }

    /**
     * Interface definition for a callback to be invoked when the checked state of a CheckableRelativeLayout changed.
     */
    public static interface OnCheckedChangeListener {
        public void onCheckedChanged(CheckableLinearLayout layout, boolean isChecked);
    }

    @Override
    public void setChecked(boolean checked) {
        mChecked = checked;

        refreshDrawableState();

        for (int i = 0; i < getChildCount(); i++) {
            View child = getChildAt(i);
            if (child instanceof Checkable) {
                ((Checkable) child).setChecked(mChecked);
            }
        }

        if (mOnCheckedChangeListener != null) {
            mOnCheckedChangeListener.onCheckedChanged(this, mChecked);
        }
    }

    @Override
    public boolean isChecked() {
        return mChecked;
    }

    @Override
    public void toggle() {
        setChecked(!mChecked);
    }

    @Override
    protected int[] onCreateDrawableState(int extraSpace) {
        final int[] drawableState = super.onCreateDrawableState(extraSpace + 1);
        if (isChecked()) {
            mergeDrawableStates(drawableState, CHECKED_STATE_SET);
        }
        return drawableState;
    }
}