package com.linj.camera.view;

import android.content.Context;
import android.graphics.Color;
import android.graphics.PorterDuff;
import android.graphics.drawable.Drawable;
import android.util.AttributeSet;
import android.view.GestureDetector;
import android.view.MotionEvent;
import android.widget.ImageView;

/** 
 * @ClassName: FilterImageView 
 * @Description:  點選時顯示明暗變化(濾鏡效果)的ImageView
 * @author LinJ
 * @date 2015-1-6 下午2:13:46 
 *  
 */
public class FilterImageView extends ImageView implements GestureDetector.OnGestureListener{
    
    /**   監聽手勢*/ 
    private GestureDetector mGestureDetector;
    public FilterImageView(Context context, AttributeSet attrs) {
        super(context, attrs);
        mGestureDetector=new GestureDetector(context, this);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        //在cancel裡將濾鏡取消,注意不要捕獲cacncel事件,mGestureDetector裡有對cancel的捕獲操作
         //在滑動GridView時,AbsListView會攔截掉Move和UP事件,直接給子控制元件返回Cancel
        if(event.getActionMasked()== MotionEvent.ACTION_CANCEL){
            removeFilter();
        }
        return mGestureDetector.onTouchEvent(event);
    }

    /**  
     *   設定濾鏡
     */
    private void setFilter() {
        //先獲取設定的src圖片
        Drawable drawable=getDrawable();
        //當src圖片為Null,獲取背景圖片
        if (drawable==null) {
            drawable=getBackground();
        }
        if(drawable!=null){
            //設定濾鏡
            drawable.setColorFilter(Color.GRAY,PorterDuff.Mode.MULTIPLY);;
        }
    }
    /**  
     *   清除濾鏡
     */
    private void removeFilter() {
        //先獲取設定的src圖片
        Drawable drawable=getDrawable();
        //當src圖片為Null,獲取背景圖片
        if (drawable==null) {
            drawable=getBackground();
        }
        if(drawable!=null){
            //清除濾鏡
            drawable.clearColorFilter();
        }
    }

    @Override
    public boolean onDown(MotionEvent e) {
        setFilter();
        //這裡必須返回true,表示捕獲本次touch事件
        return true;
    }

    @Override
    public void onShowPress(MotionEvent e) {
        // TODO Auto-generated method stub

    }

    @Override
    public boolean onSingleTapUp(MotionEvent e) {
        removeFilter();
        performClick();    
        return false;
    }

    @Override
    public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,
            float distanceY) {
        // TODO Auto-generated method stub
        return false;
    }

    @Override
    public void onLongPress(MotionEvent e) {
        //長安時,手動觸發長安事件
        performLongClick();
    }

    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
            float velocityY) {
        // TODO Auto-generated method stub
        return false;
    }
}