Apply visual Transformations to child views of ViewGroup

• Quick Code :

private void init() {
    // Enable static transformations so each child will
    // have getChildStaticTransformation() called.
        setStaticTransformationsEnabled(true);
    }
    @Override
    protected boolean getChildStaticTransformation(View child,
                                                   Transformation t) {
        // Clear any existing transformation
        t.clear();
        if (getOrientation() == HORIZONTAL) {
        // Scale children based on distance from left edge
            float delta = 1.0f - ((float) child.getLeft() / getWidth());
            t.getMatrix().setScale(delta, delta, child.getWidth() / 2,
                    child.getHeight() / 2);
        } else {
            // Scale children based on distance from top edge
            float delta = 1.0f - ((float) child.getTop() / getHeight());
            t.getMatrix().setScale(delta, delta, child.getWidth() / 2,
                    child.getHeight() / 2);
            //Also apply a fade effect based on its location
            t.setAlpha(delta);
        }
        return true;
    }

• It is possible to add transformations such as rotation, scale and alpha to ViewGroups without resorting to animations.
• This is also very convenient in applying transformations from the context of a parent view such as scale or color that changes with position
• The first step in enabling these transformations is calling

  setStaticTranformationsEnabled(true)

during the initialization of the ViewGroup class.(Usually in the constructor)

• Then implement the

          getChildStaticTransformation(View child,Transformation t)

override method and in there apply your transformations.

• You have to return true from this method. This way, the system knows it should apply your transformations to the particular child view.
• visual effects such as rotation or scale are actually applied to the Matrix of the Transformation
• We call getMatrix().setScale() and passing in the scale factor and the pivot point
• The pivot point is the location about which the scale will take place
• Relevant files :
  • https://github.com/blikoon/Ubufundi/blob/master/App1.14.0/app/src/main/java/com/blikoon/app1140/PerspectiveLayout.java