/**
 * Copyright (c) 2012 Todoroo Inc
 *
 * See the file "LICENSE" for the full license governing this code.
 */
package com.todoroo.astrid.ui;

import android.content.Context;
import android.util.AttributeSet;
import android.view.ViewDebug;
import android.widget.Checkable;
import android.widget.ImageView;

public class CheckableImageView extends ImageView implements Checkable {

    private static final int[] CHECKED_STATE_SET = {
        android.R.attr.state_checked
    };

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

    public static interface OnCheckedChangeListener {
        public void onCheckedChanged(Checkable c, boolean isChecked);
    }

    @Override
    public boolean performClick() {
        toggle();
        return super.performClick();
    }

    private boolean mChecked;
    private boolean mBroadcasting;
    private OnCheckedChangeListener mOnCheckedChangeListener;

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

    @ViewDebug.ExportedProperty
    public boolean isChecked() {
        return mChecked;
    }

    /**
     * <p>Changes the checked state of this button.</p>
     *
     * @param checked true to check the button, false to uncheck it
     */
    public void setChecked(boolean checked) {
        if (mChecked != checked) {
            mChecked = checked;
            refreshDrawableState();

            // Avoid infinite recursions if setChecked() is called from a listener
            if (mBroadcasting) {
                return;
            }

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

            mBroadcasting = false;
        }
    }

    /**
     * Register a callback to be invoked when the checked state of this button
     * changes.
     *
     * @param listener the callback to call on checked state change
     */
    public void setOnCheckedChangeListener(OnCheckedChangeListener listener) {
        mOnCheckedChangeListener = listener;
    }

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

    @Override
    protected void drawableStateChanged() {
        super.drawableStateChanged();

        if (getDrawable() != null) {
            int[] myDrawableState = getDrawableState();

            // Set the state of the Drawable
            getDrawable().setState(myDrawableState);

            invalidate();
        }
    }
}