Maybe too late, but I guess somebody might find it useful.
Activity:
public class MainActivity extends Activity implements View.OnClickListener {
String myLog = "myLog";
AlphaAnimation inAnimation;
AlphaAnimation outAnimation;
FrameLayout progressBarHolder;
Button button;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
button = (Button) findViewById(R.id.button);
progressBarHolder = (FrameLayout) findViewById(R.id.progressBarHolder);
button.setOnClickListener(this);
}
@Override
public void onClick(View v) {
switch (v.getId()) {
case R.id.button:
new MyTask().execute();
break;
}
}
private class MyTask extends AsyncTask <Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
button.setEnabled(false);
inAnimation = new AlphaAnimation(0f, 1f);
inAnimation.setDuration(200);
progressBarHolder.setAnimation(inAnimation);
progressBarHolder.setVisibility(View.VISIBLE);
}
@Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
outAnimation = new AlphaAnimation(1f, 0f);
outAnimation.setDuration(200);
progressBarHolder.setAnimation(outAnimation);
progressBarHolder.setVisibility(View.GONE);
button.setEnabled(true);
}
@Override
protected Void doInBackground(Void... params) {
try {
for (int i = 0; i < 5; i++) {
Log.d(myLog, "Emulating some task.. Step " + i);
TimeUnit.SECONDS.sleep(1);
}
} catch (InterruptedException e) {
e.printStackTrace();
}
return null;
}
}
}
Layout xml:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Start doing stuff"
android:id="@+id/button"
android:layout_below="@+id/textView"
android:layout_centerHorizontal="true" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:attr/textAppearanceLarge"
android:text="Do Some Stuff"
android:id="@+id/textView"
android:layout_alignParentTop="true"
android:layout_centerHorizontal="true" />
<FrameLayout
android:id="@+id/progressBarHolder"
android:animateLayoutChanges="true"
android:visibility="gone"
android:alpha="0.4"
android:background="#000000"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ProgressBar
style="?android:attr/progressBarStyleLarge"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:indeterminate="true"
android:layout_gravity="center" />
</FrameLayout>
</RelativeLayout>