title: Android Canvas drawLine
body: <p>I have a custom layout to draw a line based on touch input. I have it drawing the line but when the user touches the screen, the line disapeers and it draws a new line. What I want it to do is to draw a new line and leave the previous line there. 
  Here is my code:</p>
  
  <pre><code>    import android.content.Context;
      import android.graphics.Canvas;
      import android.graphics.Color;
      import android.graphics.Paint;
      import android.util.AttributeSet;
      import android.view.MotionEvent;
      import android.view.View;
  
      public class DrawView extends View {
        Paint paint = new Paint();
        float startX;
        float startY;
        float stopX;
        float stopY;
  
        public DrawView(Context context, AttributeSet attrs) {
          super(context, attrs);
  
          paint.setAntiAlias(true);
          paint.setStrokeWidth(6f);
          paint.setColor(Color.BLACK);
          paint.setStyle(Paint.Style.STROKE);
          paint.setStrokeJoin(Paint.Join.ROUND);
        }
  
        @Override
        protected void onDraw(Canvas canvas) {
            canvas.drawLine(startX, startY, stopX, stopY, paint);
        }
  
        @Override
                public boolean onTouchEvent(MotionEvent event) {
  
         switch (event.getAction()) {
          case MotionEvent.ACTION_DOWN:
              startX = event.getX();
              startY = event.getY();
            return true;
          case MotionEvent.ACTION_MOVE:
            stopX = event.getX();
            stopY = event.getY();
           break;
          case MotionEvent.ACTION_UP:    
              stopX = event.getX();
              stopY = event.getY();
            break;
          default:
            return false;
          }
            Invalidate();
          return true;
        }
      } 
  </code></pre>