Android-------自定义圆形图片实现多点触控

详情见链接:http://www.cnblogs.com/gaoliangjie/p/5569671.html

public class MyView extends ImageView {
    private Paint p;
    static final int NONE = 0;
    static final int DRAG = 1;     //拖动中
    static final int ZOOM = 2;     //缩放中
    static final int BIGGER = 3;   //放大ing
    static final int SMALLER = 4;  //缩小ing
    private int mode = NONE;       //当前的事件

    private float beforeLenght;   //两触点距离
    private float afterLenght;    //两触点距离
    private float scale = 0.04f;  //缩放的比例 X Y方向都是这个值 越大缩放的越快

    private int screenW;
    private int screenH;

    /*处理拖动 变量 */
    private int start_x;
    private int start_y;
    private int stop_x;
    private int stop_y;

    private TranslateAnimation trans; //处理超出边界的动画


    public MyView(Context context) {
        super(context);
    }

    public MyView(Context context, AttributeSet attrs) {
        super(context, attrs);
        p = new Paint();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        p.setColor(Color.YELLOW);
        canvas.drawCircle(100, 100, 50, p);
    }

    private Bitmap getCircleBitmap(Bitmap bitmap, int pixels) {
        Bitmap output = Bitmap.createBitmap(bitmap.getWidth(), bitmap.getHeight(), Bitmap.Config.ARGB_8888);
        Canvas canvas = new Canvas(output);
        final int color = 0xff424242;
        final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
        p.setAntiAlias(true);
        int x = bitmap.getWidth();
        canvas.drawCircle(x / 2, x / 2, x / 2, p);
        p.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
        canvas.drawBitmap(bitmap, rect, rect, p);
        return output;

    }
    /**
     * 该构造函数在动态创建时,指定图片的初始高宽
     * @param context
     * @param w
     * @param h
     */
    public MyView(Context context,int w,int h) {
        super(context);
        this.setPadding(0, 0, 0, 0);
        screenW = w;
        screenH = h;
    }
    /**
     * 就算两点间的距离
     */
    private float spacing(MotionEvent event) {
        float x = event.getX(0) - event.getX(1);
        float y = event.getY(0) - event.getY(1);
        double d=x*x+y*y;
        return (float) Math.sqrt(d);
    }
    /**
     * 处理触碰..
     */
    @Override
    public boolean onTouchEvent(MotionEvent event)
    {
        switch (event.getAction() & MotionEvent.ACTION_MASK) {
            case MotionEvent.ACTION_DOWN:
                mode = DRAG;
                stop_x = (int) event.getRawX();
                stop_y = (int) event.getRawY();
                start_x = (int) event.getX();
                start_y = stop_y - this.getTop();
                String s = String.valueOf(start_x);
                Toast.makeText(getContext(),"当前点击的x的值:"+s,Toast.LENGTH_SHORT).show();
                if (event.getPointerCount() == 2)
                    beforeLenght = spacing(event);
                break;
            case MotionEvent.ACTION_POINTER_DOWN:
                if (spacing(event) > 10f) {
                    mode = ZOOM;
                    beforeLenght = spacing(event);
                }
                break;
            case MotionEvent.ACTION_UP:
           /*判断是否超出范围     并处理*/
                int disX = 0;
                int disY = 0;
                if(getHeight()<=screenH || this.getTop()<0)
                {
                    if(this.getTop()<0 )
                    {
                        int dis = getTop();
                        this.layout(this.getLeft(), 0, this.getRight(), 0 + this.getHeight());
                        disY = dis - getTop();
                    }
                    else if(this.getBottom()>screenH)
                    {
                        disY = getHeight()- screenH+getTop();
                        this.layout(this.getLeft(), screenH-getHeight(), this.getRight(), screenH);
                    }
                }
                if(getWidth()<=screenW)
                {
                    if(this.getLeft()<0)
                    {
                        disX = getLeft();
                        this.layout(0, this.getTop(), 0+getWidth(), this.getBottom());
                    }
                    else if(this.getRight()>screenW)
                    {
                        disX = getWidth()-screenW+getLeft();
                        this.layout(screenW-getWidth(), this.getTop(), screenW, this.getBottom());
                    }
                }
                if(disX!=0 || disY!=0)
                {
                    trans = new TranslateAnimation(disX, 0, disY, 0);
                    trans.setDuration(500);
                    this.startAnimation(trans);
                }
                mode = NONE;
                break;
            case MotionEvent.ACTION_POINTER_UP:
                mode = NONE;
                break;
            case MotionEvent.ACTION_MOVE:
                /*处理拖动*/
                if (mode == DRAG) {
                    if(Math.abs(stop_x-start_x-getLeft())<88 && Math.abs(stop_y - start_y-getTop())<85)
                    {
                        this.setPosition(stop_x - start_x, stop_y - start_y, stop_x + this.getWidth() - start_x, stop_y - start_y + this.getHeight());
                        stop_x = (int) event.getRawX();
                        stop_y = (int) event.getRawY();
                    }
                }
                /*处理缩放*/
                else if (mode == ZOOM) {
                    if(spacing(event)>10f)
                    {
                        afterLenght = spacing(event);
                        float gapLenght = afterLenght - beforeLenght;
                        if(gapLenght == 0) {
                            break;
                        }
                        else if(Math.abs(gapLenght)>5f)
                        {
                            if(gapLenght>0) {

                                this.setScale(scale,BIGGER);
                            }else {
                                this.setScale(scale,SMALLER);
                            }
                            beforeLenght = afterLenght;
                        }
                    }
                }
                break;
        }
        return true;

    }
    /**
     * 实现处理缩放
     */
    private void setScale(float temp,int flag) {

        if(flag==BIGGER) {
            this.setFrame(this.getLeft()-(int)(temp*this.getWidth()),
                    this.getTop()-(int)(temp*this.getHeight()),
                    this.getRight()+(int)(temp*this.getWidth()),
                    this.getBottom()+(int)(temp*this.getHeight()));
        }else if(flag==SMALLER){
            this.setFrame(this.getLeft()+(int)(temp*this.getWidth()),
                    this.getTop()+(int)(temp*this.getHeight()),
                    this.getRight()-(int)(temp*this.getWidth()),
                    this.getBottom()-(int)(temp*this.getHeight()));
        }
    }

    /**
     * 实现处理拖动
     */
    private void setPosition(int left,int top,int right,int bottom) {
        this.layout(left,top,right,bottom);
    }


}
 
Android-------自定义圆形图片实现多点触控