（四）实现菜单点击弹出提示框

      在上一篇文章中，我们给菜单的点击设置了动画，如果你没有阅读过，可以单击下面的链接：
http://www.cnblogs.com/fuly550871915/p/4930699.html

      贴出上一篇文章实现的效果图吧。如下：

      下面我们要实现的逻辑也很简单，点击菜单，弹出一个提示框。怎么实现呢，只需要在ArcMenu中提供一个回调接口即可。这样子，我们就可以在MainActivity中重写回调方法，然后再ArcMenu中点击菜单时调用即可。

      修改ArcMenu中的代码如下：

package com.example.menu;

import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.animation.Animation;
import android.view.animation.Animation.AnimationListener;
import android.view.animation.AlphaAnimation;
import android.view.animation.AnimationSet;
import android.view.animation.RotateAnimation;
import android.view.animation.ScaleAnimation;
import android.view.animation.TranslateAnimation;
import android.view.ViewGroup;

public class ArcMenu extends ViewGroup implements OnClickListener{
    /**
     * 菜单按钮
     */
    private View mCBMenu;
    /**
     * 菜单的位置，为枚举类型
     * @author fuly1314
     *
     */
    private enum Position
    {
        LEFT_TOP,LEFT_BOTTOM,RIGHT_TOP,RIGHT_BOTTOM
    }
    /**
     * 菜单的状态
     * @author fuly1314
     *
     */
    private enum Status
    {
        OPEN,CLOSE
    }
    /**
     * 菜单为当前位置，默认为RIGHT_BOTTOM，在后面我们可以获取到
     */
    private Position mPosition = Position.RIGHT_BOTTOM;
    /**
     * 菜单的当前状态,默认为关闭
     */
    private Status mCurStatus = Status.CLOSE;
    
    /**
     * 菜单的半径，默认为120dp
     */
    
    /**
     * 提供一个回调接口，用来处理菜单的点击事件，点击后需要处理的事情
     */
    public interface ArcMenuListener
 58     {
 59         void dealMenuClick(View v);
 60     }
 61     public void setOnArcMenuListener(ArcMenuListener listener){
 62         
 63         mListener = listener;
 64     }
 65     private ArcMenuListener mListener;
 66     
    
    
    private int mRadius = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 150,
            getResources().getDisplayMetrics());

    
    
    public ArcMenu(Context context) {
        this(context,null);
    }
    public ArcMenu(Context context, AttributeSet attrs) {
        this(context,attrs,0);
    }
    public ArcMenu(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        
        TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.ArcMenu, defStyle, 0);
        //获取到菜单设置的位置
        int position = ta.getInt(R.styleable.ArcMenu_position, 3);
        
        switch(position){
        case 0:
            mPosition = Position.LEFT_TOP;
            break;
        case 1:
            mPosition = Position.LEFT_BOTTOM;
            break;
        case 2:
            mPosition = Position.RIGHT_TOP;
            break;
        case 3:
            mPosition = Position.RIGHT_BOTTOM;
            break;
        }
        
        //获取到菜单的半径
        mRadius = (int) ta.getDimension(R.styleable.ArcMenu_radius,
                TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 120,
                        getResources().getDisplayMetrics()));            
        ta.recycle();
        
    }
    
    
    
    /**
     * 测量各个子View的大小
     */
    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) 
    {
        int count = getChildCount();//获取子view的数量
        
        for(int i=0;i<count;i++)
        {
            //测量子view的大小
            measureChild(getChildAt(i), widthMeasureSpec, heightMeasureSpec);
        }
        
        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    }

    /**
     * 摆放各个子view的位置
     */
    protected void onLayout(boolean changed, int l, int t, int r, int b) {
        
        if(changed)//如果发生了改变，就重新布局
        {
            layoutMainMenu();//菜单按钮的布局
            /**
             * 下面的代码为菜单的布局
             */
            int count = getChildCount();
            
            for(int i=0;i<count-1;i++)
            {
                View childView = getChildAt(i+1);//注意这里过滤掉菜单按钮，只要菜单选项view
                
                childView.setVisibility(GONE);//先让菜单消失
                
                int left = (int) (mRadius*Math.cos(Math.PI/2/(count-2)*i));
                int top = (int) (mRadius*Math.sin(Math.PI/2/(count-2)*i));

                
                
                switch(mPosition)
                {
                
                case LEFT_TOP:
                    break;
                case LEFT_BOTTOM:
                    top = getMeasuredHeight() - top-childView.getMeasuredHeight();
                    break;
                case RIGHT_TOP:
                    left = getMeasuredWidth() - left-childView.getMeasuredWidth();
                    break;
                case RIGHT_BOTTOM:
                    left = getMeasuredWidth() - left-childView.getMeasuredWidth();
                    top = getMeasuredHeight() - top-childView.getMeasuredHeight();
                    break;
                }
                
                childView.layout(left, top, left+childView.getMeasuredWidth(),
                        top+childView.getMeasuredHeight());
            }
        }

        
    }
    /**
     * 菜单按钮的布局
     */
    private void layoutMainMenu() {
        
         mCBMenu = getChildAt(0);//获得主菜单按钮
         
         mCBMenu.setOnClickListener(this);
        
        int left=0;
        int top=0;
        
        switch(mPosition)
        {
        case LEFT_TOP:
            left = 0;
            top = 0;
            break;
        case LEFT_BOTTOM:
            left = 0;
            top = getMeasuredHeight() - mCBMenu.getMeasuredHeight();
            break;
        case RIGHT_TOP:
            left = getMeasuredWidth() - mCBMenu.getMeasuredWidth();
            top = 0;
            break;
        case RIGHT_BOTTOM:
            left = getMeasuredWidth() - mCBMenu.getMeasuredWidth();
            top = getMeasuredHeight() - mCBMenu.getMeasuredHeight();
            break;
        }
        
        mCBMenu.layout(left, top, left+mCBMenu.getMeasuredWidth(), top+mCBMenu.getMeasuredHeight());
    }
    /**
     * 菜单按钮的点击事件
     * @param v
     */
    public void onClick(View v) {
        //为菜单按钮设置点击动画
        RotateAnimation rAnimation = new RotateAnimation(0f, 720f, Animation.RELATIVE_TO_SELF, 0.5f, 
                Animation.RELATIVE_TO_SELF, 0.5f);
        
        rAnimation.setDuration(300);
        
        rAnimation.setFillAfter(true);
        
        v.startAnimation(rAnimation);
        
        dealChildMenu(300);//处理菜单选项，比如折叠菜单或者展开菜单
        
    }
    /**
     * 处理菜单选项，比如折叠菜单或者展开菜单
     * @param duration 菜单选项的动画时间
     */
    private void dealChildMenu(int duration) 
    {
        
        //下面的代码为菜单选项设置动画
        
        int count = getChildCount();
        
        for(int i=0;i<count-1;i++)
        {
            final View childView = getChildAt(i+1);
            
            AnimationSet set = new AnimationSet(true);
            
            //1.首先是平移动画
            TranslateAnimation tAnimation = null;
            
            //平移的x方向和y方向的距离
            int x = (int) (mRadius*Math.cos(Math.PI/2/(count-2)*i));
            int y = (int) (mRadius*Math.sin(Math.PI/2/(count-2)*i));
            
            
            
            
            //平移的标志，是平移一个正数还以一个负数
            int xflag =1;
            int yflag =1;
        
            if(mPosition == Position.LEFT_TOP||mPosition == Position.LEFT_BOTTOM)
            {
                xflag = -1;
            }
            if(mPosition == Position.LEFT_TOP||mPosition == Position.RIGHT_TOP)
            {
                yflag = -1;
            }
            
            if(mCurStatus == Status.CLOSE)//如果当前状态为关闭则应该打开
            {
                 tAnimation = new TranslateAnimation(xflag*x, 0,
                        yflag*y, 0);
                tAnimation.setDuration(duration);
                tAnimation.setFillAfter(true);
    
            }else//否则为打开状态，就应该关闭
            {
                 tAnimation = new TranslateAnimation( 0,xflag*x,
                            0,yflag*y);
                    tAnimation.setDuration(duration);
                    tAnimation.setFillAfter(true);
                    
            }
            tAnimation.setStartOffset((i * 100) / count);
            tAnimation.setAnimationListener(new AnimationListener() {
                

                public void onAnimationStart(Animation animation) {
    
                    
                }
                

                public void onAnimationRepeat(Animation animation) {
        
                    
                }
                

                public void onAnimationEnd(Animation animation) {

                    if(mCurStatus == Status.CLOSE)
                    {
                        childView.setVisibility(GONE);
                        childView.setClickable(false);
                        childView.setFocusable(false);
                    }
                    if(mCurStatus == Status.OPEN)
                    {
                        childView.setVisibility(VISIBLE);//设置菜单可见
                        //为打开状态，则菜单是可点击和获得焦点
                        childView.setClickable(true);
                        childView.setFocusable(true);
                    }
                    
                }
            });
            
            //2.然后是旋转动画
            RotateAnimation rAnimation = new RotateAnimation(0f, 0, Animation.RELATIVE_TO_SELF, 0.5f, 
                    Animation.RELATIVE_TO_SELF, 0.5f);
            rAnimation.setDuration(duration);
            rAnimation.setFillAfter(true);//动画结束是画面停留在此动画的最后一帧
            
            
            set.addAnimation(rAnimation);//一定要注意顺序，先旋转动画，然后再平移
            set.addAnimation(tAnimation);
            
            childView.startAnimation(set);
            
            //为菜单项设置点击事件
            final int cPos = i+1;
            childView.setOnClickListener(new OnClickListener() {
                
                @Override
                public void onClick(View v) {
                    
                    clickAnimation(cPos);//点击动画
                    
339                     if(mListener != null)//处理点击事件的逻辑
340                     {
341                         mListener.dealMenuClick(childView);
342                     }
343                     
                    changeStatus();
                    
                    
                }
            });
            
            
        }
        
        changeStatus();//动画完成后，要改变状态
        
    }
    /**
     * 改变状态
     */
    private void changeStatus() {
        
        mCurStatus = (mCurStatus == Status.CLOSE?Status.OPEN:Status.CLOSE);
        
    }
    /**
     * 菜单项的点击动画
     * @param cPos  用来判断当前点击的是哪一个菜单
     */
    private void clickAnimation(int cPos) {
        
        for(int i=0;i<getChildCount()-1;i++)
        {
            View childView = getChildAt(i+1);
            
            if(i+1== cPos)
            {
                AnimationSet set = new AnimationSet(true);
                ScaleAnimation sAnimation = new ScaleAnimation(1.0f, 3.0f, 1.0f, 3.0f,
                        Animation.RELATIVE_TO_SELF, 0.5f,Animation.RELATIVE_TO_SELF, 0.5f);
                sAnimation.setFillAfter(true);
                AlphaAnimation alAnimation = new AlphaAnimation(1.0f, 0f);
                alAnimation.setFillAfter(true);
                
                set.addAnimation(sAnimation);
                set.addAnimation(alAnimation);
                
                set.setDuration(300);
                childView.startAnimation(set);
                
            }else
            {
                AnimationSet set = new AnimationSet(true);
                ScaleAnimation sAnimation = new ScaleAnimation(1.0f, 0.0f, 1.0f, 0.0f,
                        Animation.RELATIVE_TO_SELF, 0.5f,Animation.RELATIVE_TO_SELF, 0.5f);
                sAnimation.setFillAfter(true);
                AlphaAnimation alAnimation = new AlphaAnimation(1.0f, 0f);
                alAnimation.setFillAfter(true);
                
                set.addAnimation(sAnimation);
                set.addAnimation(alAnimation);
                
                set.setDuration(300);
                childView.startAnimation(set);
            }
            childView.setVisibility(GONE);
        }
        
    }

}

       红色部分是我们添加的主要代码。无非就是一个回调接口，没事什么好解释的了。

      下面修改MainActivity中的代码即可，如下：

package com.example.menu;

import com.example.menu.ArcMenu.ArcMenuListener;

import android.os.Bundle;
import android.view.View;
import android.widget.Toast;
import android.app.Activity;

public class MainActivity extends Activity implements ArcMenuListener {

    private ArcMenu menu;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        
        menu = (ArcMenu) findViewById(R.id.id_menu);
        menu.setOnArcMenuListener(this);
    }


    public void dealMenuClick(View v) {
24         
25         Toast.makeText(this, "这是"+v.getTag(), Toast.LENGTH_SHORT).show();
26         
27     }
    
}

        我们看红色部分的代码，重写了回调方法。无非就是获取之前布局中ImageView中设置的tag，然后把它放在提示框中罢了。运行程序效果如下：

       至此，我们的这个案例终结了。主要难点就是自定义ViewGroup，相信你通过这个案例，对自定义ViewGroup应该有了很好的了解了。