Sample code unnessecary complicated

[GoogleCodeExporter]

Here is some sample code which would be much easier to understand

/**
 * PhotoSorterView.java
 * 
 * (c) Luke Hutchison (luke.hutch@mit.edu)
 * 
 * TODO: Add OpenGL acceleration.
 * 
 * Released under the Apache License v2.
 */
package eksempler.multitouch;

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Paint.Style;
import android.view.MotionEvent;
import android.view.View;
import eksempler.multitouch.MultiTouchController;
import eksempler.multitouch.MultiTouchController.MultiTouchObjectCanvas;
import eksempler.multitouch.MultiTouchController.PointInfo;
import eksempler.multitouch.MultiTouchController.PositionAndScale;
import org.simpla.R;

public class Multitouch0View extends View implements MultiTouchObjectCanvas {

    private MultiTouchController multiTouchController = new MultiTouchController(this);

    private PointInfo currTouchPoints = new PointInfo();

    private Paint mLinePaintTouchPointCircle = new Paint();
  private Bitmap img;
  private float x = 100;
  private float y = 100;;
  private float scale = 1;
  private float angle = 0;

    // ---------------------------------------------------------------------------------------------------

    public Multitouch0View(Context context) {
    super(context);
    img = BitmapFactory.decodeResource(getResources(), R.drawable.car);
        mLinePaintTouchPointCircle.setColor(Color.YELLOW);
        mLinePaintTouchPointCircle.setStrokeWidth(5);
        mLinePaintTouchPointCircle.setStyle(Style.STROKE);
        mLinePaintTouchPointCircle.setAntiAlias(true);
        setBackgroundColor(Color.BLACK);
    }

    // ---------------------------------------------------------------------------------------------------

    @Override
    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
    canvas.save();
    canvas.scale(scale, scale, x, y);
    canvas.rotate(angle * 180.0f / (float) Math.PI, x, y);
    canvas.drawBitmap(img, x, y, null);
    canvas.restore();
    drawMultitouchDebugMarks(canvas);
    }

    // ---------------------------------------------------------------------------------------------------

    private void drawMultitouchDebugMarks(Canvas canvas) {
        if (currTouchPoints.isDown()) {
            float[] xs = currTouchPoints.getXs();
            float[] ys = currTouchPoints.getYs();
            float[] pressures = currTouchPoints.getPressures();
            int numPoints = currTouchPoints.getNumTouchPoints();
            for (int i = 0; i < numPoints; i++)
                canvas.drawCircle(xs[i], ys[i], 50 + pressures[i] * 80, mLinePaintTouchPointCircle);
            if (numPoints == 2)
                canvas.drawLine(xs[0], ys[0], xs[1], ys[1], mLinePaintTouchPointCircle);
        }
    }

    // ---------------------------------------------------------------------------------------------------

    /** Pass touch events to the MT controller */
    @Override
    public boolean onTouchEvent(MotionEvent event) {
        return multiTouchController.onTouchEvent(event);
    }

    /** Get the image that is under the single-touch point, or return null (canceling the drag op) if none */
    public Object getDraggableObjectAtPoint(PointInfo pt) {
    return this;
    }

    /**
     * Select an object for dragging. Called whenever an object is found to be under the point (non-null is returned by getDraggableObjectAtPoint())
     * and a drag operation is starting. Called with null when drag op ends.
     */
    public void selectObject(Object obj, PointInfo touchPoint) {
        currTouchPoints.set(touchPoint);
        invalidate();
    }

    /** Get the current position and scale of the selected image. Called whenever a drag starts or is reset. */
    public void getPositionAndScale(Object obj, PositionAndScale objPosAndScaleOut) {
        objPosAndScaleOut.set(x, y, true, scale, false, scale, scale,   true, angle);
    }

    /** Set the position and scale of the dragged/stretched image. */
    public boolean setPositionAndScale(Object obj, PositionAndScale newPosAndScale, PointInfo touchPoint) {
        currTouchPoints.set(touchPoint);
    x = newPosAndScale.getXOff();
    y = newPosAndScale.getYOff();
    scale = newPosAndScale.getScale();
    angle = newPosAndScale.getAngle();
    invalidate();
        return true;
    }
}

Original issue reported on code.google.com by jacob.nordfalk on 13 Dec 2010 at 12:35

[GoogleCodeExporter]

I have a error at " R.drawable.car" in line  
img = BitmapFactory.decodeResource(getResources(), R.drawable.car);
Why ?

Original comment by khangcnt...@gmail.com on 4 Jan 2013 at 5:15

[GoogleCodeExporter]

I assume you'll need an image "car.png" in your drawables directory (but I 
didn't write the code)...

Original comment by luke.hutch on 5 Jan 2013 at 1:26