Custom Android Image Crop

Question

i just want to share this piece of code that i wrote. I tried searching for a custom crop activity, but most of them leads to the default "com.android.camera.action.CROP" despite the question custom crop, or freehand crop activity. Anyway, i just made one for myself, and hopefully it will help you guys.

public class CropView extends ImageView {

    Paint paint = new Paint();
    private int initial_size = 300;
    private static Point leftTop, rightBottom, center, previous;

    private static final int DRAG= 0;
    private static final int LEFT= 1;
    private static final int TOP= 2;
    private static final int RIGHT= 3;
    private static final int BOTTOM= 4;

    private int imageScaledWidth,imageScaledHeight;
    // Adding parent class constructors   
    public CropView(Context context) {
        super(context);
        initCropView();
    }

    public CropView(Context context, AttributeSet attrs) {
        super(context, attrs, 0);
        initCropView();
    }

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

    @Override
    protected void onDraw(Canvas canvas)
    {
        super.onDraw(canvas);
        if(leftTop.equals(0, 0))
            resetPoints();
        canvas.drawRect(leftTop.x, leftTop.y, rightBottom.x, rightBottom.y, paint);
    }

    @Override
    public boolean onTouchEvent(MotionEvent event) {
        int eventaction = event.getAction();
        switch (eventaction) { 
            case MotionEvent.ACTION_DOWN:
                previous.set((int)event.getX(), (int)event.getY());
                break; 
            case MotionEvent.ACTION_MOVE: 
                if(isActionInsideRectangle(event.getX(), event.getY())) {
                    adjustRectangle((int)event.getX(), (int)event.getY());
                    invalidate(); // redraw rectangle
                    previous.set((int)event.getX(), (int)event.getY());
                }
                break; 
            case MotionEvent.ACTION_UP: 
                previous = new Point();
                break;
        }         
        return true;
    }

    private void initCropView() {
        paint.setColor(Color.YELLOW);
        paint.setStyle(Style.STROKE);
        paint.setStrokeWidth(5);  
        leftTop = new Point();
        rightBottom = new Point();
        center = new Point();
        previous = new Point();
    }

    public void resetPoints() {
        center.set(getWidth()/2, getHeight()/2);
        leftTop.set((getWidth()-initial_size)/2,(getHeight()-initial_size)/2);
        rightBottom.set(leftTop.x+initial_size, leftTop.y+initial_size);
    }

    private static boolean isActionInsideRectangle(float x, float y) {
        int buffer = 10;
        return (x>=(leftTop.x-buffer)&&x<=(rightBottom.x+buffer)&& y>=(leftTop.y-buffer)&&y<=(rightBottom.y+buffer))?true:false;
    }

    private boolean isInImageRange(PointF point) {
        // Get image matrix values and place them in an array
        float[] f = new float[9];
        getImageMatrix().getValues(f);

        // Calculate the scaled dimensions
        imageScaledWidth = Math.round(getDrawable().getIntrinsicWidth() * f[Matrix.MSCALE_X]);
        imageScaledHeight = Math.round(getDrawable().getIntrinsicHeight() * f[Matrix.MSCALE_Y]);

        return (point.x>=(center.x-(imageScaledWidth/2))&&point.x<=(center.x+(imageScaledWidth/2))&&point.y>=(center.y-(imageScaledHeight/2))&&point.y<=(center.y+(imageScaledHeight/2)))?true:false;
    }

    private void adjustRectangle(int x, int y) {
        int movement;
        switch(getAffectedSide(x,y)) {
            case LEFT:
                movement = x-leftTop.x;
                if(isInImageRange(new PointF(leftTop.x+movement,leftTop.y+movement)))
                    leftTop.set(leftTop.x+movement,leftTop.y+movement);
                break;
            case TOP:
                movement = y-leftTop.y;
                if(isInImageRange(new PointF(leftTop.x+movement,leftTop.y+movement)))
                    leftTop.set(leftTop.x+movement,leftTop.y+movement);
                break;
            case RIGHT:
                movement = x-rightBottom.x;
                if(isInImageRange(new PointF(rightBottom.x+movement,rightBottom.y+movement)))
                    rightBottom.set(rightBottom.x+movement,rightBottom.y+movement);
                break;
            case BOTTOM:
                movement = y-rightBottom.y;
                if(isInImageRange(new PointF(rightBottom.x+movement,rightBottom.y+movement)))
                    rightBottom.set(rightBottom.x+movement,rightBottom.y+movement);
                break;      
            case DRAG:
                movement = x-previous.x;
                int movementY = y-previous.y;
                if(isInImageRange(new PointF(leftTop.x+movement,leftTop.y+movementY)) && isInImageRange(new PointF(rightBottom.x+movement,rightBottom.y+movementY))) {
                    leftTop.set(leftTop.x+movement,leftTop.y+movementY);
                    rightBottom.set(rightBottom.x+movement,rightBottom.y+movementY);
                }
                break;
        }
    }

    private static int getAffectedSide(float x, float y) {
        int buffer = 10;
        if(x>=(leftTop.x-buffer)&&x<=(leftTop.x+buffer))
            return LEFT;
        else if(y>=(leftTop.y-buffer)&&y<=(leftTop.y+buffer))
            return TOP;
        else if(x>=(rightBottom.x-buffer)&&x<=(rightBottom.x+buffer))
            return RIGHT;
        else if(y>=(rightBottom.y-buffer)&&y<=(rightBottom.y+buffer))
            return BOTTOM;
        else
            return DRAG;
    }

    public byte[] getCroppedImage() {
        BitmapDrawable drawable = (BitmapDrawable)getDrawable();
        float x = leftTop.x-center.x+(drawable.getBitmap().getWidth()/2);
        float y = leftTop.y-center.y+(drawable.getBitmap().getHeight()/2);
        Bitmap cropped = Bitmap.createBitmap(drawable.getBitmap(),(int)x,(int)y,(int)rightBottom.x-(int)leftTop.x,(int)rightBottom.y-(int)leftTop.y);
        ByteArrayOutputStream stream = new ByteArrayOutputStream();
        cropped.compress(Bitmap.CompressFormat.PNG, 100, stream);
        return stream.toByteArray();
    }
}

What i did was, i extended the ImageView and added Cropping powers. It is pretty easy to use. Once the class is saved, just use it in the layout like this.

    <"your package name".CropView
        android:id="@+id/image_preview"
        android:layout_width="fill_parent"
        android:layout_height="match_parent" />

Thats it! Hope it helps! If you encounter any problem, please feel free to ask :)

Answer 1

You should try:

@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);

    setContentView(R.layout.crop_layout);


    myCropView = new CropView(this);

    Uri imageUri = getIntent().getExtras().getParcelable("path");

    b = (BitmapDrawable) BitmapDrawable.createFromPath(imageUri.getPath()); 

    myCropView.setImageURI(imageUri);
}

(Taken from an edit to your question.)

Answer 2

thanks thehippo... but i've solved finding the view by the layout

Uri imageUri = getIntent().getExtras().getParcelable("path");
    b = (BitmapDrawable) BitmapDrawable.createFromPath(getRealPathFromURI(imageUri));
    myCropView = (CropView) findViewById(R.id.image_preview);
    myCropView.setBackground(b);

but now i can't handle the touch event. The rectangle stay still even if i touch the screen...

EDIT: ok, i've made it works. But now, the rectangle move only inside a smaller area, not in the entire image. I suppose that there's something wrong here

private boolean isInImageRange(PointF point) {
    // Get image matrix values and place them in an array
    float[] f = new float[9];
    getImageMatrix().getValues(f);

    // Calculate the scaled dimensions
    imageScaledWidth = Math.round(getBackground().getIntrinsicWidth() * f[Matrix.MSCALE_X]);
    imageScaledHeight = Math.round(getBackground().getIntrinsicHeight() * f[Matrix.MSCALE_Y]);

    return (point.x>=(center.x-(imageScaledWidth/2))&&point.x<=(center.x+(imageScaledWidth/2))&&point.y>=(center.y-(imageScaledHeight/2))&&point.y<=(center.y+(imageScaledHeight/2)))?true:false;
}

i've done a little change to make work the code: getBackground() instead of getDrawable

EDIT 2: OK ive got it, i was doing this in the wrong way. You're code is good. To set the image i was using the view.seBackground()...instead of view.setImageDrawable(). Now everything works. Maybe i will only check if it's possible to create a larger area that fires the scaling of the rectangle