IconView.java

package com.thu.ttlgm.component;

import android.content.Context;
import android.util.AttributeSet;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.FrameLayout;
import android.widget.ImageView;

import com.facebook.rebound.BaseSpringSystem;
import com.facebook.rebound.SimpleSpringListener;
import com.facebook.rebound.Spring;
import com.facebook.rebound.SpringSystem;
import com.facebook.rebound.SpringUtil;
import com.makeramen.RoundedImageView;

/**
 * Created by SemonCat on 2014/3/18.
 */
public class IconView extends RoundedImageView{

    private BaseSpringSystem mBaseSpringSystem;
    private Spring mScaleSpring;
    private Spring mTranslationLeftSpring;
    private Spring mTranslationRightSpring;

    private int initialX;
    private int initialY;
    private float initialTouchX;
    private float initialTouchY;

    private int lastX,lastY,right,left,top,bottom;
    private float x1,y1,x2,y2;

    private final int mClickEventDistance = dip2px(10);

    private int screenWidth;
    private int screenHeight;

    public IconView(Context context) {
        super(context);
        init();
    }

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

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



    private void init(){

        initScreenValue();
        setupRebound();
    }

    private void initScreenValue(){
        screenWidth = getResources().getDisplayMetrics().widthPixels;
        screenHeight = getResources().getDisplayMetrics().heightPixels;
    }

    private void setupRebound(){
        mBaseSpringSystem = SpringSystem.create();
        mScaleSpring = mBaseSpringSystem.createSpring()
                .addListener(new SimpleSpringListener() {
                    @Override
                    public void onSpringUpdate(Spring spring) {
                        float scale = (float) SpringUtil.mapValueFromRangeToRange(spring.getCurrentValue(), 0, 1, 1, 0.7);
                        setScaleX(scale);
                        setScaleY(scale);

                    }
                });

        mTranslationLeftSpring = mBaseSpringSystem.createSpring().
                addListener(new SimpleSpringListener(){
                    @Override
                    public void onSpringUpdate(Spring spring) {
                        float translationX = (float) SpringUtil.mapValueFromRangeToRange(spring.getCurrentValue(), 0, 1, getX(), 0);

                        updateX((int)translationX);

                    }

                    @Override
                    public void onSpringAtRest(Spring spring) {
                        mTranslationLeftSpring.setEndValue(0);
                    }
                });

        mTranslationRightSpring = mBaseSpringSystem.createSpring().
                addListener(new SimpleSpringListener(){
                    @Override
                    public void onSpringUpdate(Spring spring) {
                        float translationX = (float) SpringUtil.mapValueFromRangeToRange(spring.getCurrentValue(), 0, 1, getX(), screenWidth-getWidth());

                        updateX((int)translationX);

                    }

                    @Override
                    public void onSpringAtRest(Spring spring) {
                        mTranslationRightSpring.setEndValue(0);
                    }
                });
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        int action = event.getAction();
        FrameLayout.LayoutParams ViewGroupParams = (FrameLayout.LayoutParams) getLayoutParams();
        switch (action) {
            case MotionEvent.ACTION_DOWN:
                //開始縮放動畫
                mScaleSpring.setEndValue(1);
                lastX = (int) event.getRawX();
                lastY = (int) event.getRawY();
                x1 =  event.getRawX();//得到相對應屏幕左上角的坐標
                y1 =  event.getRawY();
                // Get current time in nano seconds.

                initialX = (int) getX();
                initialY = (int) getY();
                initialTouchX = event.getRawX();
                initialTouchY = event.getRawY();
                break;
            case MotionEvent.ACTION_UP:
                x2 = event.getRawX();
                y2 = event.getRawY();

                //結束縮放動畫
                mScaleSpring.setEndValue(0);

                //判斷彈回動畫
                if (ViewGroupParams.leftMargin<screenWidth/2)
                    mTranslationLeftSpring.setEndValue(1);
                else{
                    mTranslationRightSpring.setEndValue(1);
                }

                //Log.i("i", x1 + ",,," + y1 + ",,," + x2 + ",,," + y2);
                double distance = Math.sqrt(Math.abs(x1-x2)*Math.abs(x1-x2)+Math.abs(y1-y2)*Math.abs(y1-y2));//兩點之間的距離
                //Log.i("i", "x1 - x2>>>>>>"+ distance);
                if (distance < mClickEventDistance)
                    performClick();
                break;
            case MotionEvent.ACTION_MOVE:

                int moveX = initialX + (int) (event.getRawX() - initialTouchX);
                int moveY = initialY + (int) (event.getRawY() - initialTouchY);

                if (moveY < 0) {moveY = 0;}
                else if (moveY > screenHeight - getHeight()) {moveY = screenHeight - getHeight();}

                //setX(moveX);
                //setY(moveY);


                ViewGroupParams.leftMargin = moveX;
                ViewGroupParams.topMargin = moveY;
                setLayoutParams(ViewGroupParams);

                int dx = (int) event.getRawX() - lastX;
                int dy = (int) event.getRawY() - lastY;

                left = getLeft() + dx;
                top = getTop() + dy;
                right = getRight() + dx;
                bottom = getBottom() + dy;
                if (left < 0) {
                    left = 0;
                    right = left + getWidth();
                }
                if (right > screenWidth) {
                    right = screenWidth;
                    left = right - getWidth();
                }
                if (top < 0) {
                    top = 0;
                    bottom = top + getHeight();
                }
                if (bottom > screenHeight) {
                    bottom = screenHeight;
                    top = bottom - getHeight();
                }
                //Log.i("i", "值：" + left +">>>"+ top+">>>"+right+">>>"+bottom);
                layout(left, top, right, bottom);
                lastX = (int) event.getRawX();
                lastY = (int) event.getRawY();

                break;

            case MotionEvent.ACTION_CANCEL:
                mScaleSpring.setEndValue(0);
                break;
        }
        //super.onTouchEvent(event);
        return true;
    }

    private void updateX(int x){
        FrameLayout.LayoutParams ViewGroupParams = (FrameLayout.LayoutParams) getLayoutParams();
        ViewGroupParams.leftMargin = x;
        setLayoutParams(ViewGroupParams);
    }

    private void updateY(int y){
        FrameLayout.LayoutParams ViewGroupParams = (FrameLayout.LayoutParams) getLayoutParams();
        ViewGroupParams.topMargin = y;
        setLayoutParams(ViewGroupParams);
    }

    private void updateXY(int x,int y){
        FrameLayout.LayoutParams ViewGroupParams = (FrameLayout.LayoutParams) getLayoutParams();
        ViewGroupParams.leftMargin = x;
        ViewGroupParams.topMargin = y;
        setLayoutParams(ViewGroupParams);
    }


    private int dip2px(float dipValue) {
        final float scale = getContext().getResources().getDisplayMetrics().density;
        return (int) (dipValue * scale + 0.5f);
    }
}