無効化コールを使用する必要がありますか？

Question

ビューを表示するアクティビティがあり、ビュー内に描画されているキャンバスがあり、次にキャンバスをドラッグ/ズームするためのオンタッチ機能があります。しかし、デバッグ時にはキャンバスの動きがないことを除いて正しく動作するように見えます。私は無効にする必要があると思います、そうですか？もしそうなら、私はそれをどこに呼びますか？

ご協力いただきありがとうございます。あなたは、画面を再描画したいとき

Touch.java

package org.example.touch; 

import android.app.Activity; 
import android.content.Context; 
import android.graphics.Matrix; 
import android.graphics.PointF; 
import android.os.Bundle; 
import android.util.FloatMath; 
import android.util.Log; 
import android.view.MotionEvent; 
import android.view.View; 
import android.view.View.OnTouchListener; 
import android.widget.ImageView; 

public class Touch extends Activity implements OnTouchListener { 
    private static final String TAG = "Touch"; 
    // These matrices will be used to move and zoom image 
    Matrix matrix = new Matrix(); 
    Matrix savedMatrix = new Matrix(); 

    // We can be in one of these 3 states 
    static final int NONE = 0; 
    static final int DRAG = 1; 
    static final int ZOOM = 2; 
    int mode = NONE; 

    // Remember some things for zooming 
    PointF start = new PointF(); 
    PointF mid = new PointF(); 
    float oldDist = 1f; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 
     GridView view = new GridView(this); 
     setContentView(view); 
     // ImageView view = (ImageView) findViewById(R.id.imageView); 
     view.setOnTouchListener(this); 

     // ... 
     // Work around a Cupcake bug 
     matrix.setTranslate(1f, 1f); 
     view.setImageMatrix(matrix); 

    } 

    @Override 
    public boolean onTouch(View v, MotionEvent rawEvent) { 
     WrapMotionEvent event = WrapMotionEvent.wrap(rawEvent); 
     // ... 
     GridView view = (GridView) v; 

     // Dump touch event to log 
     dumpEvent(event); 

     // Handle touch events here... 
     switch (event.getAction() & MotionEvent.ACTION_MASK) { 
     case MotionEvent.ACTION_DOWN: 
     savedMatrix.set(matrix); 
     start.set(event.getX(), event.getY()); 
     Log.d(TAG, "mode=DRAG"); 
     mode = DRAG; 
     break; 
     case MotionEvent.ACTION_POINTER_DOWN: 
     oldDist = spacing(event); 
     Log.d(TAG, "oldDist=" + oldDist); 
     if (oldDist > 10f) { 
      savedMatrix.set(matrix); 
      midPoint(mid, event); 
      mode = ZOOM; 
      Log.d(TAG, "mode=ZOOM"); 
     } 
     break; 
     case MotionEvent.ACTION_UP: 
     case MotionEvent.ACTION_POINTER_UP: 
     mode = NONE; 
     Log.d(TAG, "mode=NONE"); 
     break; 
     case MotionEvent.ACTION_MOVE: 
     if (mode == DRAG) { 

      matrix.set(savedMatrix); 
      matrix.postTranslate(event.getX() - start.x, 
        event.getY() - start.y); 
     } 
     else if (mode == ZOOM) { 
      float newDist = spacing(event); 
      Log.d(TAG, "newDist=" + newDist); 
      if (newDist > 10f) { 
       matrix.set(savedMatrix); 
       float scale = newDist/oldDist; 
       matrix.postScale(scale, scale, mid.x, mid.y); 
      } 
     } 
     break; 
     } 

     view.setImageMatrix(matrix); 
     return true; // indicate event was handled 
    } 

    /** Show an event in the LogCat view, for debugging */ 
    private void dumpEvent(WrapMotionEvent event) { 
     // ... 
     String names[] = { "DOWN", "UP", "MOVE", "CANCEL", "OUTSIDE", 
      "POINTER_DOWN", "POINTER_UP", "7?", "8?", "9?" }; 
     StringBuilder sb = new StringBuilder(); 
     int action = event.getAction(); 
     int actionCode = action & MotionEvent.ACTION_MASK; 
     sb.append("event ACTION_").append(names[actionCode]); 
     if (actionCode == MotionEvent.ACTION_POINTER_DOWN 
      || actionCode == MotionEvent.ACTION_POINTER_UP) { 
     sb.append("(pid ").append(
       action >> MotionEvent.ACTION_POINTER_ID_SHIFT); 
     sb.append(")"); 
     } 
     sb.append("["); 
     for (int i = 0; i < event.getPointerCount(); i++) { 
     sb.append("#").append(i); 
     sb.append("(pid ").append(event.getPointerId(i)); 
     sb.append(")=").append((int) event.getX(i)); 
     sb.append(",").append((int) event.getY(i)); 
     if (i + 1 < event.getPointerCount()) 
      sb.append(";"); 
     } 
     sb.append("]"); 
     Log.d(TAG, sb.toString()); 
    } 

    /** Determine the space between the first two fingers */ 
    private float spacing(WrapMotionEvent event) { 
     // ... 
     float x = event.getX(0) - event.getX(1); 
     float y = event.getY(0) - event.getY(1); 
     return FloatMath.sqrt(x * x + y * y); 
    } 

    /** Calculate the mid point of the first two fingers */ 
    private void midPoint(PointF point, WrapMotionEvent event) { 
     // ... 
     float x = event.getX(0) + event.getX(1); 
     float y = event.getY(0) + event.getY(1); 
     point.set(x/2, y/2); 
    } 
} 

とビューは、GridView.java

package org.example.touch; 

import android.app.Activity; 
import android.os.Bundle; 

import android.view.View; 
import android.content.Context; 
import android.graphics.Canvas; 
import android.graphics.Color; 
import android.graphics.Paint; 
import android.graphics.Paint.Style; 
import android.view.Display; 
import android.graphics.Path; 
import android.graphics.Bitmap; 
import android.graphics.Matrix; 
import android.graphics.Bitmap.Config; 
import android.widget.ImageView; 


public class GridView extends ImageView { 

    private int canvasWidth; 
    private int canvasHeight; 

    // private Config config; 
    // private Bitmap bitmap; 
    // private Canvas canvas; 

    public GridView(Context context) { 
     super(context); 




    // config = Bitmap.Config.ARGB_8888; 
    // bitmap = Bitmap.createBitmap(canvasWidth, canvasHeight, config); 
    // canvas = new Canvas(bitmap); 

    } 


public void onDraw(Canvas canvas){ 
    super.onDraw(canvas); 

    canvasWidth = canvas.getWidth(); 
    canvasHeight = canvas.getHeight(); 

    Paint paint = new Paint(); 
    paint.setStyle(Paint.Style.FILL); 

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


    canvas.drawRect(0, 0, (float)canvasWidth, (float)canvasHeight, paint); 

    int Grid_size = canvasWidth/32; 


    paint.setStyle(Style.STROKE); 
     paint.setColor(Color.RED); 
     for (int i = 1; i < 100; i++) {     
       canvas.drawLine((Grid_size*i), 10, (Grid_size*i), 10+(Grid_size*10), paint);    
       }     
     paint.setColor(Color.RED); 
      for (int i = 1; i < 12; i++) {         
        canvas.drawLine(10, (Grid_size*i), (Grid_size*99), (Grid_size*i), paint); 
      } 
      final int FS= 500;     //Sampling Frequency 
      final int WIN=FS*20; 

      //create a test sine wave 
      short[]wave = new short[WIN]; 
      int frequency = 1; 
      int amplitude = 40; 
      for (int n=0; n<WIN; n++) 
       wave[n] = (short) (60.0+amplitude*Math.sin(6.282*frequency*n/FS)); 

      //To display the waveform 

      Path path2 = new Path(); 
      path2.moveTo(10, 60); 

      for (float x2=1; x2<WIN; x2++) 
       path2.lineTo(10+(3*x2/50), wave[(int) x2]); 
      Paint paint3 = new Paint(); 
      paint3.setColor(Color.BLACK); 
      paint3.setStyle(Style.STROKE); 
      canvas.drawPath(path2, paint3); 
} 


//public void invalidate(); 

public void setImageMatrix(Matrix matrix) { 
    super.setImageMatrix(matrix); 

}} 

Answer 1

コールのために無効にします。常に更新したい場合は、onDrawステージの最後に呼び出すことができます。それは何度も何度も描画します。

あなただけのズーム機能が