I like the approach in Kostya But's answer.
Building on that, here's a couple of ideas to make the same overlay easily reusable across your app:
Consider putting the overlay FrameLayout in a separate layout file, e.g. res/layout/include_progress_overlay
:
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/progress_overlay"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:alpha="0.4"
android:animateLayoutChanges="true"
android:background="@android:color/black"
android:clickable="true"
android:visibility="gone">
<ProgressBar
style="?android:attr/progressBarStyleLarge"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:indeterminate="true"/>
</FrameLayout>
(One thing I added in the overlay FrameLayout is android:clickable="true"
. So while the overlay is shown, it prevents clicks going through to UI elements underneath it. At least in my typical use cases this is what I want.)
Then include it where needed:
<!-- Progress bar overlay; shown while login is in progress -->
<include layout="@layout/include_progress_overlay"/>
And in code:
View progressOverlay;
[...]
progressOverlay = findViewById(R.id.progress_overlay);
[...]
// Show progress overlay (with animation):
AndroidUtils.animateView(progressOverlay, View.VISIBLE, 0.4f, 200);
[...]
// Hide it (with animation):
AndroidUtils.animateView(progressOverlay, View.GONE, 0, 200);
With animation code extracted into a util method:
/**
* @param view View to animate
* @param toVisibility Visibility at the end of animation
* @param toAlpha Alpha at the end of animation
* @param duration Animation duration in ms
*/
public static void animateView(final View view, final int toVisibility, float toAlpha, int duration) {
boolean show = toVisibility == View.VISIBLE;
if (show) {
view.setAlpha(0);
}
view.setVisibility(View.VISIBLE);
view.animate()
.setDuration(duration)
.alpha(show ? toAlpha : 0)
.setListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator animation) {
view.setVisibility(toVisibility);
}
});
}
(Here using view.animate()
, added in API 12, instead of AlphaAnimation
.)