Add elevation/shadow on toolbar for pre-lollipop devices

Question

I updated my android app to the new material design, but I also wanted to add some shadow or elevation to the Toolbar. There seem to be some (hacky) ways of doing it via ima

Answer 1

I have a CollapsingToolbarLayout with Toolbar and a Toolbar-like View that moves up and down, but lays above NestedScrollView, like in https://github.com/k0shk0sh/CoordinatorLayoutExample. I tried many variants. Sometimes a shadow scrolled above a screen with NestedScrollView, sometimes the Toolbar drew a solid shadow without transparency, sometimes the shadow was aliased. Anyway, this is my solution.

Say, you have a layout:

Add a shadow (drawable/shadow.xml):

Add this method. Here scrollShadow is a view named "scroll_shadow":

private void setShadowVisibility(int visibility) {
    if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
        scrollShadow.setVisibility(visibility);
    }
}

Manipulate it as you wish. It will show a gradient on pre-Lollipop devices and shows a normal shadow for Android 5.0+.