android on touch draw line

Question

I have a code that get the coordinate of image view, and i want to draw a line when the user touch 2 times in the imageview. The imageview has a bitmap from drawable. for more detail this is my code : ``` public class MainActivity extends Activity implements OnTouchListener { ImageView tampil; Matrix matrix = new Matrix(); Matrix savedMatrix = new Matrix(); private static final String TAG = "Touch"; 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; float x1, y1, x2, y2; Bitmap bmp; int i = 1; @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); tampil = (ImageView)findViewById(R.id.imageView1); tampil.setOnTouchListener(this); Drawable d = getResources().getDrawable(R.drawable.enigma); bmp = ((BitmapDrawable)d).getBitmap(); tampil.setImageBitmap(…

Accepted Answer

this is the correct working code :)

```
package com.example.stackdrawline;

import android.os.Bundle;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.Bitmap.Config;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.PointF;
import android.graphics.drawable.BitmapDrawable;
import android.graphics.drawable.Drawable;
import android.util.Log;
import android.view.MotionEvent;
import android.view.View;
import android.view.View.OnTouchListener;
import android.widget.ImageView;

public class StackActivity extends Activity implements OnTouchListener {
ImageView tampil;
   Matrix matrix = new Matrix();
   Matrix savedMatrix = new Matrix();
   private static final String TAG = "Touch";
   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;
   float x1, y1, x2, y2;
   Bitmap bmp;
   int i = 1;

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_stack);
    tampil = (ImageView)findViewById(R.id.imageView1);
    tampil.setOnTouchListener(this);
    Drawable d = getResources().getDrawable(R.drawable. enigma);
    bmp = ((BitmapDrawable)d).getBitmap();
    tampil.setImageBitmap(bmp);

}

@Override
public boolean onTouch(View v, MotionEvent event) {
    // TODO Auto-generated method stub
    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;
         Log.i(TAG, "("+String.valueOf((int)event.getX())+","+String.valueOf((int)event.getY())+")");
         if (i==1){
             x1 = event.getX();
             y1 = event.getY();
             i = 2;
             Log.i(TAG, "coordinate x1 : "+String.valueOf(x1)+" y1 : "+String.valueOf(y1));
         } else if (i==2){
             x2 = event.getX();
             y2 = event.getY();
             i = 3;
             Log.i(TAG, "coordinate x2 : "+String.valueOf(x2)+" y2 : "+String.valueOf(y2));
             onDraw();
         } 
        break;
      }
    return true;
}
public void onDraw(){
    bmp = Bitmap.createBitmap(tampil.getWidth(), tampil.getHeight(), Config.ARGB_8888);
    Canvas c = new Canvas(bmp);
    tampil.draw(c);

Paint pnt = new Paint();
    pnt.setColor(Color.RED);
    c.drawLine(x1, y1, x2, y2, pnt);
    tampil.setImageBitmap(bmp);
    i = 1;
}

}
```

android on touch draw line

Solution

Problem