Strange issues with view switcher after object animator animations
- by Barry Irvine
I have two LinearLayout views that contain a number of edit texts and checkboxes for entering user information (name, email address etc). When a validation fails on one of these fields a gone textview is displayed showing the validation error.
I have enclosed the two layouts within a ViewSwitcher and I animate between the two views using the ObjectAnimator class. (Since the code needs to support older versions of Android I am actually using the nineoldandroids backwards compatibility library for this).
The bulk of the work is performed in my switchToChild method.
If I flip the views more than twice then I start to run into strange errors.
Firstly although the correct child view of the view animator is displayed it seems that the other view has focus and I can click on the views beneath the current one. I resolved this issue by adding a viewSwitcher.bringChildToFront at the end of the first animation.
When I do this however and perform a validation on the 2nd view the "gone" view that I have now set to visible is not displayed (as if the linearlayout is never being re-measured). Here is a subset of the XML file:
<ScrollView
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_below="@+id/TitleBar"
android:scrollbarAlwaysDrawVerticalTrack="true"
android:scrollbarStyle="outsideOverlay"
android:scrollbars="vertical" >
<ViewSwitcher
android:id="@+id/switcher"
android:layout_width="fill_parent"
android:layout_height="wrap_content" >
<LinearLayout
android:id="@+id/page_1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
<!-- Lots of subviews here -->
<LinearLayout
android:id="@+id/page_2"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
And this is the main method for flipping between the views:
private void switchToChild(final int child) {
final ViewSwitcher viewSwitcher = (ViewSwitcher) findViewById(R.id.switcher);
if (viewSwitcher.getDisplayedChild() != child) {
final Interpolator accelerator = new AccelerateInterpolator();
final Interpolator decelerator = new DecelerateInterpolator();
final View visibleView;
final View invisibleView;
switch (child) {
case 0:
visibleView = findViewById(R.id.page_2);
invisibleView = findViewById(R.id.page_1);
findViewById(R.id.next).setVisibility(View.VISIBLE);
findViewById(R.id.back).setVisibility(View.GONE);
break;
case 1:
default:
visibleView = findViewById(R.id.page_1);
invisibleView = findViewById(R.id.page_2);
findViewById(R.id.back).setVisibility(View.VISIBLE);
findViewById(R.id.next).setVisibility(View.GONE);
break;
}
final ObjectAnimator visToInvis = ObjectAnimator.ofFloat(visibleView, "rotationY", 0f, 90f).setDuration(250);
visToInvis.setInterpolator(accelerator);
final ObjectAnimator invisToVis = ObjectAnimator.ofFloat(invisibleView, "rotationY", -90f, 0f).setDuration(250);
invisToVis.setInterpolator(decelerator);
visToInvis.addListener(new AnimatorListenerAdapter() {
@Override
public void onAnimationEnd(Animator anim) {
viewSwitcher.showNext();
invisToVis.start();
viewSwitcher.bringChildToFront(invisibleView); // If I don't do this the old view can have focus
}
});
visToInvis.start();
}
}
Does anyone have any ideas? This is really confusing me!
