如何使視圖觸摸事件可調整大小

Question

請參見下面的圖像

我想通過拖動其角來改變突出視圖的形狀..拖動一角應該是長方形後不練琴的觀點它可以是任意的任意形狀

如何實現這個？

現在我已經做了4個角上的觸摸事件，移動，但形狀不改變

package com.assignment.DragDrop; 

import android.content.Context; 
import android.graphics.Bitmap; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.graphics.Point; 
import android.graphics.drawable.BitmapDrawable; 
import android.graphics.drawable.Drawable; 
import android.view.MotionEvent; 
import android.view.View; 
import android.widget.ImageView; 

public class DrawView extends View { 


    Point point1,point2,point3,point4; 
    private ColorBall[] colorballs = new ColorBall[4]; // array that holds the balls 
    private int balID = 0; // variable to know what ball is being dragged 
    Paint paint; 
    Canvas canvas; 
    public DrawView(Context context) { 
     super(context); 
     paint=new Paint(); 
     setFocusable(true); //necessary for getting the touch events 
     canvas= new Canvas(); 
     // setting the start point for the balls 
     point1 = new Point(); 
     point1.x = 50; 
     point1.y = 20; 

     point2 = new Point(); 
     point2.x = 150; 
     point2.y = 20; 

     point3 = new Point(); 
     point3.x = 150; 
     point3.y = 120; 

     point4 = new Point(); 
     point4.x = 50; 
     point4.y = 120; 


     // declare each ball with the ColorBall class 
     colorballs[0] = new ColorBall(context,R.drawable.bol_blauw, point1); 
     colorballs[1] = new ColorBall(context,R.drawable.bol_blauw, point2); 
     colorballs[2] = new ColorBall(context,R.drawable.bol_groen, point3); 
     colorballs[3] = new ColorBall(context,R.drawable.bol_geel, point4); 


    } 

    // the method that draws the balls 
    @Override protected void onDraw(Canvas canvas) { 
     //canvas.drawColor(0xFFCCCCCC);  //if you want another background color  

     paint.setAntiAlias(true); 
     paint.setDither(true); 
     paint.setColor(Color.BLACK); 
     paint.setStyle(Paint.Style.FILL); 
     paint.setStrokeJoin(Paint.Join.ROUND); 
     // mPaint.setStrokeCap(Paint.Cap.ROUND); 
     paint.setStrokeWidth(5); 


      canvas.drawPaint(paint); 
      paint.setColor(Color.WHITE); 

      canvas.drawRect(point1.x+25, point2.x, point3.x+25, point4.x, paint); 
      BitmapDrawable mBitmap; 
      mBitmap= new BitmapDrawable(); 

     // canvas.drawBitmap(bitmap, left, top, paint) 
     // shade_region_between_points(); 
     // canvas.drawLine(point1.x, point1.y, point2.x, point2.y, paint); 
     // canvas.drawLine(point1.x, point1.y, point4.x, point4.y, paint); 

     // canvas.drawLine(point4.x, point4.y, point3.x, point3.y, paint); 
     // canvas.drawLine(point2.x, point2.y, point3.x, point3.y, paint); 
      //draw the balls on the canvas 
     for (ColorBall ball : colorballs) { 
      canvas.drawBitmap(ball.getBitmap(), ball.getX(), ball.getY(), paint); 
      // canvas.drawLine(point1.x, point1.y, point2.x, point2.y, paint); 

    // canvas.drawRect(point1.x, point2.x, point3.x, point4.x, paint); 



     } 
     /*Drawable drawable = getResources().getDrawable(R.drawable.ic_launcher); 
     drawable.setBounds(point1.x+25, point2.x, point3.x+25, point4.x); 
     drawable.draw(canvas);*/ 
    } 

    // events when touching the screen 
    public boolean onTouchEvent(MotionEvent event) { 
     int eventaction = event.getAction(); 

     int X = (int)event.getX(); 
     int Y = (int)event.getY(); 

     switch (eventaction) { 

     case MotionEvent.ACTION_DOWN: // touch down so check if the finger is on a ball 
      balID = 0; 
      for (ColorBall ball : colorballs) { 
       // check if inside the bounds of the ball (circle) 
       // get the center for the ball 
       int centerX = ball.getX() + 25; 
       int centerY = ball.getY() + 25; 
       paint.setColor(Color.CYAN); 
       // calculate the radius from the touch to the center of the ball 
       double radCircle = Math.sqrt((double) (((centerX-X)*(centerX-X)) + (centerY-Y)*(centerY-Y))); 
       // canvas.drawLine(point1.x, point1.y, point2.x, point2.y, paint); 

       // if the radius is smaller then 23 (radius of a ball is 22), then it must be on the ball 
       if (radCircle < 23){ 

        balID = ball.getID(); 
        canvas.drawRect(point1.x, point2.x, point3.x, point4.x, paint); 

        invalidate(); 
        break; 
       } 
       invalidate(); 

       //canvas.drawRect(point1.x, point2.x, point3.x, point4.x, paint); 
       // check all the bounds of the ball (square) 
       //if (X > ball.getX() && X < ball.getX()+50 && Y > ball.getY() && Y < ball.getY()+50){ 
       // balID = ball.getID(); 
       // break; 
       //} 
      } 

      break; 


     case MotionEvent.ACTION_MOVE: // touch drag with the ball 
      // move the balls the same as the finger 
      if (balID > 0) { 
      try { 
       colorballs[balID-1].setX(X-25); 
        colorballs[balID-1].setY(Y-25); 
        // canvas.drawLine(point1.x, point1.y, point2.x, point2.y, paint); 

      } catch (Exception e) { 
       // TODO Auto-generated catch block 
       e.printStackTrace(); 
      } 
      paint.setColor(Color.CYAN); 
      canvas.drawRect(point1.x, point2.x, point3.x, point4.x, paint); 
      invalidate(); 
      } 

      break; 

     case MotionEvent.ACTION_UP: 
      // touch drop - just do things here after dropping 

      break; 
     } 
     // redraw the canvas 
     invalidate(); 
     return true; 

    } 


    public void shade_region_between_points() 
    { 
     canvas.drawRect(point1.x, point2.x, point3.x, point4.x, paint); 
    } 
} 

我從網上這段代碼。

這將能夠在觸摸事件，但形狀不動移動角落...

Answer 1

它就像當我們裁剪圖像，然後它增加你的rectangle.Then的大小，我們可以我們的觀點另存爲新位圖。所以你可以從this question獲得幫助。

這解釋了你需要的幾乎相同的東西。

OR

如果它是佈局然後我們可以設定新的佈局-PARAM用新的高度和寬度時，我們接觸任何視圖

Answer 2

以下代碼是汲取觸摸基矩形。

import java.util.ArrayList; 

import android.content.Context; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.graphics.Point; 
import android.graphics.drawable.BitmapDrawable; 
import android.util.AttributeSet; 
import android.view.MotionEvent; 
import android.view.View; 

import com.common.Utils; 
import com.example.rectangleoverlay.R; 

public class DrawView extends View { 

    Point point1, point3; 
    Point point2, point4; 

    /** 
    * point1 and point 3 are of same group and same as point 2 and point4 
    */ 
    int groupId = -1; 
    private ArrayList<ColorBall> colorballs = new ArrayList<ColorBall>(); 
    // array that holds the balls 
    private int balID = 0; 
    // variable to know what ball is being dragged 
    Paint paint; 
    Canvas canvas; 

    public DrawView(Context context) { 
     super(context); 
     paint = new Paint(); 
     setFocusable(true); // necessary for getting the touch events 
     canvas = new Canvas(); 
     // setting the start point for the balls 
     point1 = new Point(); 
     point1.x = 50; 
     point1.y = 20; 

     point2 = new Point(); 
     point2.x = 150; 
     point2.y = 20; 

     point3 = new Point(); 
     point3.x = 150; 
     point3.y = 120; 

     point4 = new Point(); 
     point4.x = 50; 
     point4.y = 120; 

     // declare each ball with the ColorBall class 
     colorballs.add(new ColorBall(context, R.drawable.gray_circle, point1)); 
     colorballs.add(new ColorBall(context, R.drawable.gray_circle, point2)); 
     colorballs.add(new ColorBall(context, R.drawable.gray_circle, point3)); 
     colorballs.add(new ColorBall(context, R.drawable.gray_circle, point4)); 

    } 

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

    public DrawView(Context context, AttributeSet attrs) { 
     super(context, attrs); 
     paint = new Paint(); 
     setFocusable(true); // necessary for getting the touch events 
     canvas = new Canvas(); 
     // setting the start point for the balls 
     point1 = new Point(); 
     point1.x = 50; 
     point1.y = 20; 

     point2 = new Point(); 
     point2.x = 150; 
     point2.y = 20; 

     point3 = new Point(); 
     point3.x = 150; 
     point3.y = 120; 

     point4 = new Point(); 
     point4.x = 50; 
     point4.y = 120; 

     // declare each ball with the ColorBall class 
     colorballs.add(new ColorBall(context, R.drawable.gray_circle, point1)); 
     colorballs.add(new ColorBall(context, R.drawable.gray_circle, point2)); 
     colorballs.add(new ColorBall(context, R.drawable.gray_circle, point3)); 
     colorballs.add(new ColorBall(context, R.drawable.gray_circle, point4)); 

    } 

    // the method that draws the balls 
    @Override 
    protected void onDraw(Canvas canvas) { 
     // canvas.drawColor(0xFFCCCCCC); //if you want another background color 

     paint.setAntiAlias(true); 
     paint.setDither(true); 
     paint.setColor(Color.parseColor("#55000000")); 
     paint.setStyle(Paint.Style.FILL); 
     paint.setStrokeJoin(Paint.Join.ROUND); 
     // mPaint.setStrokeCap(Paint.Cap.ROUND); 
     paint.setStrokeWidth(5); 

     canvas.drawPaint(paint); 
     paint.setColor(Color.parseColor("#55FFFFFF")); 

     if (groupId == 1) { 
      canvas.drawRect(point1.x + colorballs.get(0).getWidthOfBall()/2, 
        point3.y + colorballs.get(2).getWidthOfBall()/2, point3.x 
          + colorballs.get(2).getWidthOfBall()/2, point1.y 
          + colorballs.get(0).getWidthOfBall()/2, paint); 
     } else { 
      canvas.drawRect(point2.x + colorballs.get(1).getWidthOfBall()/2, 
        point4.y + colorballs.get(3).getWidthOfBall()/2, point4.x 
          + colorballs.get(3).getWidthOfBall()/2, point2.y 
          + colorballs.get(1).getWidthOfBall()/2, paint); 
     } 
     BitmapDrawable mBitmap; 
     mBitmap = new BitmapDrawable(); 

     // draw the balls on the canvas 
     for (ColorBall ball : colorballs) { 
      canvas.drawBitmap(ball.getBitmap(), ball.getX(), ball.getY(), 
        new Paint()); 

     } 
    } 

    // events when touching the screen 
    public boolean onTouchEvent(MotionEvent event) { 
     int eventaction = event.getAction(); 

     int X = (int) event.getX(); 
     int Y = (int) event.getY(); 

     switch (eventaction) { 

     case MotionEvent.ACTION_DOWN: // touch down so check if the finger is on 
             // a ball 
      balID = -1; 
      groupId = -1; 
      for (ColorBall ball : colorballs) { 
       // check if inside the bounds of the ball (circle) 
       // get the center for the ball 
       Utils.logd("Id : " + ball.getID()); 
       Utils.logd("getX : " + ball.getX() + " getY() : " + ball.getY()); 
       int centerX = ball.getX() + ball.getWidthOfBall(); 
       int centerY = ball.getY() + ball.getHeightOfBall(); 
       paint.setColor(Color.CYAN); 
       // calculate the radius from the touch to the center of the ball 
       double radCircle = Math 
         .sqrt((double) (((centerX - X) * (centerX - X)) + (centerY - Y) 
           * (centerY - Y))); 

       Utils.logd("X : " + X + " Y : " + Y + " centerX : " + centerX 
         + " CenterY : " + centerY + " radCircle : " + radCircle); 

       if (radCircle < ball.getWidthOfBall()) { 

        balID = ball.getID(); 
        Utils.logd("Selected ball : " + balID); 
        if (balID == 1 || balID == 3) { 
         groupId = 2; 
         canvas.drawRect(point1.x, point3.y, point3.x, point1.y, 
           paint); 
        } else { 
         groupId = 1; 
         canvas.drawRect(point2.x, point4.y, point4.x, point2.y, 
           paint); 
        } 
        invalidate(); 
        break; 
       } 
       invalidate(); 
      } 

      break; 

     case MotionEvent.ACTION_MOVE: // touch drag with the ball 
      // move the balls the same as the finger 
      if (balID > -1) { 
       Utils.logd("Moving Ball : " + balID); 

       colorballs.get(balID).setX(X); 
       colorballs.get(balID).setY(Y); 

       paint.setColor(Color.CYAN); 

       if (groupId == 1) { 
        colorballs.get(1).setX(colorballs.get(0).getX()); 
        colorballs.get(1).setY(colorballs.get(2).getY()); 
        colorballs.get(3).setX(colorballs.get(2).getX()); 
        colorballs.get(3).setY(colorballs.get(0).getY()); 
        canvas.drawRect(point1.x, point3.y, point3.x, point1.y, 
          paint); 
       } else { 
        colorballs.get(0).setX(colorballs.get(1).getX()); 
        colorballs.get(0).setY(colorballs.get(3).getY()); 
        colorballs.get(2).setX(colorballs.get(3).getX()); 
        colorballs.get(2).setY(colorballs.get(1).getY()); 
        canvas.drawRect(point2.x, point4.y, point4.x, point2.y, 
          paint); 
       } 

       invalidate(); 
      } 

      break; 

     case MotionEvent.ACTION_UP: 
      // touch drop - just do things here after dropping 

      break; 
     } 
     // redraw the canvas 
     invalidate(); 
     return true; 

    } 

    public void shade_region_between_points() { 
     canvas.drawRect(point1.x, point3.y, point3.x, point1.y, paint); 
    } 
} 

下面的類用於存儲對象

import android.content.Context; 
import android.graphics.Bitmap; 
import android.graphics.BitmapFactory; 
import android.graphics.Point; 

public class ColorBall { 

    Bitmap bitmap; 
    Context mContext; 
    Point point; 
    int id; 
    static int count = 0; 

    public ColorBall(Context context, int resourceId, Point point) { 
     this.id = count++; 
     bitmap = BitmapFactory.decodeResource(context.getResources(), 
       resourceId); 
     mContext = context; 
     this.point = point; 
    } 

    public int getWidthOfBall() { 
     return bitmap.getWidth(); 
    } 

    public int getHeightOfBall() { 
     return bitmap.getHeight(); 
    } 

    public Bitmap getBitmap() { 
     return bitmap; 
    } 

    public int getX() { 
     return point.x; 
    } 

    public int getY() { 
     return point.y; 
    } 

    public int getID() { 
     return id; 
    } 

    public void setX(int x) { 
     point.x = x; 
    } 

    public void setY(int y) { 
     point.y = y; 
    } 
}