Develop Reference

Removing the extra top space in CoordinatorLayout- Android

I am trying to use BottomSheetBehavior to make a layout similar to what google maps is providing. I am successful in using the BottomSheetBehavior and create slide up layout. The problem I am having now is CordinatorLayout takes extra space even when my layout is collapsed.
Below is a screenshot of my layout.
White background in my main activity layout
Pink is my collapsed layout with peekHeight
And the grey background is the one which should be transparent but takes the extra space.
My main layout file
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<FrameLayout
android:layout_width="match_parent"
android:layout_alignParentBottom="true"
android:layout_height="wrap_content">
<include layout="#layout/sample_coordinator" />
</FrameLayout>
CordinatorLayout with BottomSheetBehavior
<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout 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="wrap_content"
android:background="#color/common_google_signin_btn_text_light_disabled">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:behavior_hideable="false"
app:layout_behavior="com.google.android.material.bottomsheet.BottomSheetBehavior">
<TextView
android:layout_width="match_parent"
android:layout_height="250dp"
android:background="#color/colorPrimary" />
</FrameLayout>

You have to use CoordinatorLayout in your activity layout.
Then in your bottom sheet layout insert these lines:
app:behavior_hideable="true"
app:behavior_peekHeight="Xdp"

View Pager contents not showing

On my Home Fragment it contains
ScrollView
LinearLayout
RecycleView
LinearLayout
TabsLayout
ViewPager
TextView (Just to test if the height of ViewPager was updated)
When opening the home screen it will show the Recycle View, Tabs Layout and Text View does not include the View Pager (I did confirm that the adapter was executed properly but the content does not show)
I did try to remove the visibility of the RecycleView and after that
the ViewPager Contents shows up.
fragment_home.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.core.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_height="match_parent"
android:layout_width="match_parent"
android:fillViewport="true"
xmlns:tools="http://schemas.android.com/tools"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/item_listing"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipToPadding="false"
android:clipChildren="false"
tools:listitem="#layout/item_categories_content"/>
<include
layout="#layout/fragment_home_news_events"/>
</LinearLayout>
</androidx.core.widget.NestedScrollView>
fragment_home_news_events.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
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="match_parent"
android:orientation="vertical">
<com.google.android.material.tabs.TabLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="#dimen/activity_margin"
app:tabSelectedTextColor="#color/colorPrimary"
android:id="#+id/fragment_home_inner_tabs">
</com.google.android.material.tabs.TabLayout>
<androidx.viewpager.widget.ViewPager
android:layout_height="match_parent"
android:layout_width="match_parent"
android:id="#+id/fragment_home_inner_tabs_content">
</androidx.viewpager.widget.ViewPager>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/text_label_status"/>
</LinearLayout>
When the RecycleView is visible
When the RecycleView is not visible

You have RecyclerView with include of another layout (fragment_home_news_events) the two had match_parent in height :(
try to fix height to fragment_home_news_events not match_parent.
or
put the height 0dp for both RecyclerView and fragment_home_news_events but with weight 1.

In a fragment,when an image is set as the background of a RelativeLayout in ScrollView, the RelativeLayout is misbehaving

I have an activity with this layout:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/fragment_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".activities.MainActivity" />
Then I have this fragment layout, which I am transacting in the fragment_container of the activity:
<?xml version="1.0" encoding="utf-8"?>
<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/scroll_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true">
<RelativeLayout
android:id="#+id/relative_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#drawable/bg_login">
</RelativeLayout>
</ScrollView>
The drawable bg_login is:
But the strange thing that is happening is, the background image(bg_login) hides all the content in RelativeLayout, in the preview pane as well as when I run the app. I can't find out why this is happening! Please help.

I dont know what you want to do, are you want have multiple background in relative layouts when scrolled or not.
But i assuming you, the scroll view when have a children element with background is not best practice.
So scoll view must set to a children from parent have a background for good practice.
This may be can help you :
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/bg_login">
<ScrollView
android:id="#+id/scroll_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true">
<RelativeLayout
android:id="#+id/relative_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</RelativeLayout>
</ScrollView>
</RelativeLayout>

How to make view container above Viewpager "scrollable" (Toolbar is inside Activity, not Fragment)?

I have fragment, which doesn´t cointains toolbar. Toolbar must stay in activity. This fragment must show main view and bellow viewpager with two fragments. Each fragment is specific. First use custom layout, second use adapter. Each has different height. I tried a lot of libs and ideas, but none of them works as it should (it made scroll longer/shorter than it should or it made crazy UI overlays).
I am trying to do UI where it looks that this all is one layout, meaning, it is scrollable from up to bottom. But I can´t figure it out. I was thinking to use CoordinatorLayout, but I have no idea how.
XML:
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="200dp"
android:background="#FF0000"
android:orientation="vertical">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="ABCDEFGH" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="GHIKJ" />
</LinearLayout>
<android.support.v4.view.ViewPager
android:id="#+id/viewPager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
</android.support.design.widget.CoordinatorLayout>
How to make this as scrollable layout in fragment without using toolbar references?
Update: Yes, here are some pictures, I hope it is more clear now.

Wrap your LinearLayout inside an AppBarLayout. Actually AppBarLayout extends LinearLayout so you could just replace your LinearLayout with it.
Even if your app doesn't have a toolbar or an app bar, the AppBarLayout is the view that CoordinatorLayout coordinates with.
Adding the AppBarLayout should provide the behavior you're looking for.

This root fragment layout seems to working. I am not sure that this is best solution, but it works.
Note: I replaced listview by standard LinearLayout as root container and inflate child layouts (items) there.
<?xml version="1.0" encoding="utf-8"?>
<android.support.design.widget.CoordinatorLayout
android:id="#+id/main_content"
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="match_parent">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="250dp"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.design.widget.CollapsingToolbarLayout
android:id="#+id/collapsing_toolbar"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_scrollFlags="scroll|enterAlways">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
</LinearLayout>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/viewPager"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"/>
</android.support.design.widget.CoordinatorLayout>
Child fragment (for viewpager):
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.NestedScrollView
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<LinearLayout
android:id="#+id/childFragment"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"/>
</android.support.v4.widget.NestedScrollView>

Overlap sibling view with RelativeLayout

I have a RelativeLayout at the top of my app. Below the RelativeLayout I have a ViewPager.
To explain this in a way that will make sense, imagine the screen's height is 700 pixels. The RelativeLayout is about 200 pixels high.
I want the RelativeLayout to be position absolutely at the top of the app such that the ViewPager is behind it. I then want to add a 200 pixel paddingTop to the ViewPager so that it appears under the RelativeLayout.
Here is the layout I have now (which is obviously not working):
<LinearLayout
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="match_parent"
android:orientation="vertical">
<RelativeLayout
android:id="#+id/header"
android:layout_width="match_parent"
android:layout_height="wrap_content">
...
</RelativeLayout>
<android.support.v4.view.ViewPager
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
/>
</LinearLayout>
I load a ListView with some data under the header:
<LinearLayout
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">
<ListView
android:id="#+id/listview"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
How can I do this?

Try changing the linearlayout to a framelayout. This will allow the views to be placed on top of each other.
Then put the code for the pageviewer above the relativelayout. This will make the pageviewer appear to be behind the relativelayout as it is rendered first, and the relativelayout rendered on top of it. Android will render views in the order in which they are declared.
Lastly, add a top margin/padding to the pageviewer to make it seem positioned below the relativelayout.

Here's what you can do:
Use RelativeLayout instead of LinearLayout as the root.
Move the ViewPager(pager) view to the top of child RelativeLayout(header)
<RelativeLayout
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="match_parent" >
<android.support.v4.view.ViewPager
android:id="#+id/pager"
android:paddingTop="200px"
android:layout_width="match_parent"
android:layout_height="match_parent" />
<RelativeLayout
android:id="#+id/header"
android:layout_width="match_parent"
android:layout_height="wrap_content">
</RelativeLayout>
</RelativeLayout>