In my Android app running on Android 5.1.1 I have a layout using a Toolbar with a TabLayout, and underneath is a ViewPager. All of these are put together in a CoordinatorLayout.
In the first page of the ViewPager is a RecyclerView serving CardView items.
My problem is that my ViewPager keeps getting resized in a way so that my CardView list items are cropped.
My main layout looks basically like this:
<android.support.design.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent" >
<android.support.design.widget.AppBarLayout
android:layout_height="wrap_content"
android:layout_width="match_parent" >
<android.support.v7.widget.Toolbar
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<android.support.design.widget.TabLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
app:layout_behavior="#string/appbar_scrolling_view_behavior"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</android.support.design.widget.CoordinatorLayout>
And the first fragment served by my ViewPager looks like:
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent" >
<android.support.v7.widget.RecyclerView
android:scrollbars="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="8dp"/>
</FrameLayout>
This renders something that looks like this:
When clicking a button in my layout, I use startActivityForResult to invoke another activity, and when returning to my activity sometimes suddenly my list is cropped so that only half of the first item is visible:
After swiping horizontally to another pager in the ViewPager and then back, the problem disappears, so it does seem a re-layout has not been properly triggered. Pressing HOME and then resuming my activity does NOT resolve the problem though. Note that this happens even if I am not modifying my layout in any way, I am simply returning from a startActivityForResult call. And yes, it only happens sometimes... And I have no background threads running that could explain the apparent random behavior.
At first I thought it was the RecyclerView that had shrunk, but using HierarchyViewer I was able to find that it was actually the entire ViewPager that had shrunk to about half its original height.
I tried various hacks to get around this, including calling invalidate() and requestLayout() on my entire view hiearchy, but nothing seemed to help (although swiping to another page and back again fixes it). Also, those are not the kind of solutions I want to resort to... Then I tried changing my ViewPager height to wrap_content, which did in fact solve this particular problem; after returning to my activity the first item in my RecyclerView is never cropped, and I can scroll down to the other items. However, now instead the very last item of my list is always cropped, as can be seen in this screenshot where the list is scrolled all the way to the bottom:
Since I am now at a point where I don't really understand what's going on, I need some help. What should I really use as the layout_height for my ViewPager, and - above all - why? To me, match_parent makes sense, but how should I be thinking here? Is there a rational reason my views got cropped when using match_parent, or did I in fact encounter a bug in ViewPager, RecyclerView and/or CoordinatorLayout? How do I make sure that my ViewPager consistently fills the entire screen area below the AppBar, and that my RecyclerView can be scrolled vertically to properly render all CardView list items?
It turns out this is almost certainly a bug in CoordinatorLayout or even more likely in AppBarLayout$ScrollingViewBehavior. In an effort to create a MCVE I realized it was the fact that my sub-activity had an IME on screen that caused the shrinking of the ViewPager - when my activity is resumed after onActivityResult, the ViewPager is shrunk as a result of reduced screen real-estate from the IME, but is never expanded again despite the fact that the IME is no longer being shown and the fact that the CoordinatorLayout is indeed expanded.
After debugging and stepping through onLayout and onMeasure of CoordinatorLayout and ViewPager I am now fairly sure that the CoordinatorLayout does not properly propagate the change in size to its children.
I found that I can "fix" the problem by calling requestLayout on my ViewPager, but only if the call is sufficiently delayed (10 ms never works, 100 ms works most of the time):
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
mHandler.postDelayed(new Runnable() {
#Override
public void run() {
mViewPager.requestLayout();
}
}, 100);
}
This obviously isn't a robust solution, but after investigating some more it turns out I probably don't even need CoordinatorLayout since I don't really have any advanced scrolling behavior. So my solution will be to simply go with a LinearLayout or RelativeLayout as my root view group instead. Nice and simple, no need to complicate things.
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<android.support.design.widget.AppBarLayout
android:layout_height="wrap_content"
android:layout_width="match_parent" >
<android.support.v7.widget.Toolbar
android:layout_width="match_parent"
android:layout_height="wrap_content" />
<android.support.design.widget.TabLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</LinearLayout>
I will however try to condense this into a simple example and file a bug with Google.
As to what I should use as the height for my ViewPager, my original use of match_parent still seems reasonable. The fact that wrap_content solved the problem (but caused other problems) is probably just due to inconsistencies caused by the bug.
I've experienced a similar issue when using an older version of the support library.
See these related issues:
https://code.google.com/p/android/issues/detail?id=176406
https://code.google.com/p/android/issues/detail?id=176187
Make sure you're using the latest Support library, version 23.1 as of this writing.
In your fragment just remove the frameLayout and make recyclerView parent...I hope it will work:
<android.support.v7.widget.RecyclerView
android:scrollbars="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_margin="8dp">
<android.support.v7.widget.RecyclerView/>
Related
I am facing a weird issue, I have a Viewpager2, the fragment page contains a Scrollview, HorizontalScrollView, and a RecyclerView.
When I launch the fragment that hosts the ViewPager the UI works, it also works if I swipe right, but as soon as I swipe left to the previous page the touch stops working, I lose the ability to swipe up and down on the page.
I feel lost here, it worked perfectly fine with the old ViewPager
ViewPager fragment page
<ScrollView
android:isScrollContainer="true"
android:measureAllChildren="true"
android:background="?backgroundColor"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
...
</androidx.constraintlayout.widget.ConstraintLayout>
<ScrollView/>
ViewPager
<androidx.viewpager2.widget.ViewPager2
android:orientation="horizontal"
android:id="#+id/pager"
android:layout_width="0dp"
android:layout_height="0dp"
...
/>
I fixed the issue by updating ViewPager's PageTransformer.
I extended ViewPager2.PageTransformer on my PageTransformer thinking the old transformer would work just fine.
Looks like this is not the case, the old version was missing the translationZ looks like not setting the translationZ causes this behavior.
I have a strange issue with NestedScrollView fling on Nexus 5x (7.1.2) and Google Pixel (7.1.1). On other OS versions it works OK.
Fling animation sometimes stops right after lifting up a finger. It stucks and the next few flings may be stopping as well.
In order to reproduce it, you need to fling several times up and down.
In logs these flings look pretty much the same in terms of velocity, direction, etc, so I can't find a real cause of this bug.
Also NestedScrollView doesn't necessarily need to be inside of CoordinatorLayout, it also can have no NestedScrollingChild at all.
For example, this bug is reproducible with one of the following NestedScrollView children:
1) LinearLayout populated with TextViews
2) WebView
3) LinearLayout populated with RecyclerViews.
I know about possible issues with RecyclerView and Behaviours inside of CoordinatorLayout, but it's not related.
So please don't mention any
recyclerView.getLayoutManager().setAutoMeasureEnabled(true);
recyclerView.setNestedScrollingEnabled(false);
or things like that.
Code sample:
<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="16dp"
android:text="Put a super long text here"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="16dp"
android:text="Put a super long text here"/>
</LinearLayout>
</android.support.v4.widget.NestedScrollView>
So it's clearly a bug in NestedScrollView.
I have made a workaround for this, but still waiting for a proper fix from Google side.
https://github.com/Dimezis/FlingableNestedScrollView/
Edit:
Looks like the issue is fixed in support lib 26.0.0-beta2
https://chris.banes.me/2017/06/09/carry-on-scrolling/
Edit 2:
Although the scrolling works fine now, in my app I can constantly reproduce this bug:
https://issuetracker.google.com/issues/37051723
If someone encounters it as well, you can find a workaround in a thread mentioned.
according to Animating a Scroll Gesture training guide, while overriding computeScroll(), after using mScroller.computeScrollOffset() to calculate proper offset to scroll view, we need use:
ViewCompat.postInvalidateOnAnimation(this);
to animate next scroll.
However, in the NestedScrollView, the computeScroll() looks like this:
public void computeScroll() {
if (mScroller.computeScrollOffset()) {
...
}
}
It doesn't request next scroll animation! Which means that after using mScroller.fling(...), the computeScroll() method will sometimes only get called one time, and view doesn't keep fling.
To fix this problem, I have tried to replace the computeScroll in this way:
public void computeScroll(){
if(mScroller.computeScrollOffset()){
...
ViewCompat.postInvalidateOnAnimation(this);
}
}
It may not sound a good solution, but it just works fine for now.
Recent version of NestedScrollView has added the ViewCompat.postInvalidateOnAnimation(this).
SwipeRefreshLayout does not work (animation not shown, onRefresh not called) when the first item in the RecyclerView within the SwipeRefreshLayout has a height of zero.
You can check out a test project on Github that shows this.
My question is: can this effect be circumvented?
In my actual project, due to circumstances not in my hand (Ad library)the first item of my list will sometimes have a height of 0, so setting it to View.GONE or height to 1 is not an option.
Found an workaround: Put RecyclerView to into additional view:
<androidx.swiperefreshlayout.widget.SwipeRefreshLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.recyclerview.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="match_parent" />
</FrameLayout>
</androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
it cause additional overdraw, but works
few more suggestions found here: https://github.com/airbnb/epoxy/issues/74
If you can get a callback from the ad library you should be able to work around the bug by adding and removing the advertisement item from your RecyclerView.Adapter depending on whether or not the ad view has content to display.
I have a situation where I need a scrollview to have a background image that shouldn't scroll along with it's parent when moving. Before any of you suggest me the links for setting background image and this that, I have already tried and it's not working.
The whole story goes like: I have an activity with fragments which have their own backgrounds with some input fields. When focusing over input fields, keyboard appears and background image squeezes. For that I put an image on background of scrollview that fixed my issue of squeezing background but raised another concern that background Image should stay static while scrolling the parent scrollview.
The second solution any of you may suggest is setting background of my activity rather playing with scrollview. That's right, but for that I had to make a style element with background of theme which appears odd while transitioning different fragments plus it adds overhead when I have a lot of code and fragments to move forward and back.
That's the point where I am stuck. I have gone through links below, if you just need to know that I tried it or not.
link1
link2
link3
... and so on
below is the layout I am using for my fragments (it's all being done programmatically)
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/top_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal" >
<ScrollView
android:id="#+id/scrollView1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true"
android:scrollbars="none" >
<FrameLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<ImageView
android:id="#+id/backgroundView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:contentDescription="#string/app_name"
android:scaleType="fitXY" />
<LinearLayout
android:id="#+id/parent_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical" >
</LinearLayout>
</FrameLayout>
</ScrollView>
</LinearLayout>
So if you guys have any better solution keeping in mind the situation I have, will be warmly welcomed. Thank you
None of the above works for me with some reason but this things works.
getWindow().setBackgroundDrawableResource(R.mipmap.img_reg_bg);
put it in oncreate method hope it will help.
If I guess right you try to fix your hotfix to get it working propperly. If I'm right you sould go back to scratch and do it without your scrollview.
If you have a look at following Link:
http://developer.android.com/guide/topics/manifest/activity-element.html#wsoft
you'll see softkeyboard mode can be adjusted. "adjustPan" should solve your problem.
"adjustPan"
The activity's main window is not resized to make room for the soft keyboard. Rather, the contents of the window are automatically panned so that the current focus is never obscured by the keyboard and users can always see what they are typing. This is generally less desirable than resizing, because the user may need to close the soft keyboard to get at and interact with obscured parts of the window.
Add someimgage to your drawable folderes, like drawable-mdpi, drawable-hdpi.
In your LinearLayout "#+id/top_layout" add attribute:
android:background="#drawable/someimage"
I am using an NSV in a CL for the ability to have the toolbar compress when the NSV scrolls down. The problem that I am having is that my NSV is not scrolled to the top when it loads, instead, it is offset from the top of the NSV by quite a margin (I am not certain where this spacing is coming from, it's not in the layout).
Please take a look at the screen captures, the first one shows how the NSV loads and you can clearly see the NSV has scrolled down quite a bit from the top by comparing the second (when I scroll the NSV to the top manually):
I did some updates to this layout and it caused this to occur, previously, it loaded at the top without issue. However, I did not add any spacing that should have caused this.
Here is the layout I'm using for this:
<android.support.design.widget.CoordinatorLayout
android:id="#+id/cl_goal_detail"
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1">
<android.support.design.widget.AppBarLayout
android:id="#+id/abl_goal_detail"
android:layout_width="match_parent"
android:layout_height="144dp"
app:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.design.widget.CollapsingToolbarLayout
android:id="#+id/collapsing_toolbar_goal_detail"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/content_space_double"
app:collapsedTitleTextAppearance="#style/title.dark"
app:expandedTitleTextAppearance="#style/display3.plus.dark"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar_goal_detail"
style="#style/toolbar"
app:layout_collapseMode="pin"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"/>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v4.widget.NestedScrollView
android:id="#+id/nsv_goal_detail"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/content_space_half"
android:paddingLeft="#dimen/content_space_half"
android:paddingRight="#dimen/content_space_half"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<FrameLayout
android:id="#+id/container_goal_detail"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="fill_vertical"/>
</android.support.v4.widget.NestedScrollView>
</android.support.design.widget.CoordinatorLayout>
Any ideas would be appreciated!
OK! After a solid DAY of debugging every single component of my layout and Fragment I identified what I believe is a bug.
First, the issue: Turns out that having elements in your NSV's child view that change visibility to View.GONE upon runtime are causing the list to scroll down. I noticed that the list scrolls to just above the element where the visibility was toggled (including any margins set on the view).
Second, the fix: I fixed this issue by setting all the views to have android:visibility="gone" in the xml layout, then, I toggle each view's visibility as needed. Previously, the views were visible by default and then I worked from there. I just needed to change my logic to start with them all GONE, not terribly difficult.
I assume this works because the views you are going to hide at runtime do not form a part of the overall height calculation when the NSV is created in onCreateView(). Once the fragment progresses past onCreateView() it's safe to dynamically change the views, however, if the views are calculated as part as the height in onCreateView() and THEN hidden with View.GONE, measurements go wonky and you end up with a list scrolled down significantly.
Have you tried adding below line in your viewgroup i.e. FrameLayout in your case
android:descendantFocusability="blocksDescendants"
I think this will also work for you.
If not try it adding in NSV.
In my case, there was an EditText near the bottom of my scrolling content that was grabbing focus. Since NestedScrollView does some weird layout stuff, the focused view didn't scroll to the top when the activity started, so the real cause was not readily apparent. Adding this to the NestedScrollView's child layout fixed it for me:
android:focusableInTouchMode="true"
Your post answer helped me a lot to find out my issue (btw, it was the same). But I got it worked in a different way. I guess you are using a RecyclerView. In my case I'm using 3 RecyclerViews. Well, from your answer I started hiding the recyclers and I found out just one of them was causing this issue. What I did is I populated with a postDelayed:
new Handler().postDelayed(new Runnable() {
#Override
public void run() {
recyler.setLayoutManager(new LinearLayoutManager(getApplicationContext()));
recyler.setAdapter(new MyAdapter(myList));
}
}, 3000);
That worked fine!