Androidplot - when does the gridRect is measured?

Question

I'm using androidplot to display a fixed-sized graph, which I've setted up a BitmapShader to match each Range interval and I need to set this shader to be always displayed on the graph, since it's beginning.

My problem is:

I can't intialize the graph with this shader (I've tested it using as base the DemoApp and the shader is working properly). Every time I try to get the GridRect using the method getGridRect() it returns null, no matter where I call this function during the activity creation. I can only set the shadder after the activity is created, but only with a button or something like it.

I searched through the entire source code but could not find where this measure occurs during the activity's lifecycle.

Answer 1

Unfortunately, I was unable the proper way of getting the gridrect mesured during it's creatiion, but I've found a way around.

I was able to define the graph height by getting the XYPlot view-height and subtract the graph top and bottom padding.

A snippet from my code:

  @Override
  protected void onCreate(Bundle savedInstanceState) {
     ...
    mPlot.getGraphWidget().setPaddingBottom(20);
    mPlot.getGraphWidget().setPaddingTop(20);
    //Added a ViewTreeObserver to be sure when the Plot was measured.
    mPlot.getViewTreeObserver().addOnGlobalLayoutListener(new OnGlobalLayoutListener() {

        @Override
        public void onGlobalLayout() {
            mPlot.getViewTreeObserver().removeOnGlobalLayoutListener(this);
            //Avoid the factory trying to scale bitmap according to Display density
            Options options = new BitmapFactory.Options();
            options.inScaled = false;
            Bitmap bm = Bitmap.createScaledBitmap(BitmapFactory.decodeResource(getResources(), R.drawable.chartbackground, options), 1, (int) mPlot.getHeight() - 40, false);
            BitmapShader backgroundShader = new BitmapShader(bm, Shader.TileMode.REPEAT, Shader.TileMode.REPEAT);
            Matrix shaderMatrix = new Matrix();
            //This matrix references always stayed the same even if the plot changed its size.
            shaderMatrix.setTranslate(49.6875f, 30.75f);
            backgroundShader.setLocalMatrix(shaderMatrix);
            mPlot.getGraphWidget().getGridBackgroundPaint().setShader(backgroundShader);
            //Setting the background to be a little bit translucid.
            mPlot.getGraphWidget().getGridBackgroundPaint().setAlpha(90);
        }

    });
    ...

  }