Develop Reference

Scrolling appbar leaving blank space on top of recyclerview

Hi, I have tried to implement the appbar scrolling behavior and it works fine, however, if I scroll when I'm right on the top it seems like there is extra space for one recyclerview row. How do I get rid of the extra space?
activity_main:
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
android:fitsSystemWindows="true">
<com.google.android.material.appbar.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_scrollFlags="scroll|snap|enterAlways" />
</com.google.android.material.appbar.AppBarLayout>
<include layout="#layout/nav_host" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
fragment_recyclerview:
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".fragments.recyclerviewFragment.RecyclerviewFragment"
>
<androidx.recyclerview.widget.RecyclerView
android:paddingTop="?attr/actionBarSize"
android:clipToPadding="false"
android:scrollbars="none"
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
/>
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:layout_gravity="bottom|right"
app:layout_anchorGravity="bottom|end|right"
app:layout_anchor="#id/recyclerView"
android:id="#+id/floatingActionButton"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="24dp"
android:backgroundTint="#color/green_300_org"
android:contentDescription="#string/add_a_task"
android:src="#drawable/ic_baseline_add_24"
app:tint="#color/black" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>

Instead of adding this attribute to the RecyclerView of fragment_recyclerview.xml:
app:layout_behavior="#string/appbar_scrolling_view_behavior"
add it in your activity_main.xml file, and it will work fine.
It will be like:
<include
layout="#layout/nav_host"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
Then you can remove the top padding from your RecyclerView, and you don't need to use CoordinatorLayout in the fragment_recyclerview.xml file as well.

Toolbar overlaps other content

I have a ViewPager that horizontally scrolls through multiple fragments, however, I've added a toolbar but it overlaps the ViewPager content.
I know there are other similar questions asked here, nothing worked for me, unfortunately.
this is the main_view.xml
<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.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.Toolbar
android:id="#+id/my_toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary" />
</android.support.design.widget.AppBarLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<android.support.v4.view.ViewPager
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
</RelativeLayout>
Probably I should add another layout somewhere, but I'm not sure where. A hint would be nice, since I've been struggling with this for the last couple of hours.

Implement like this
<?xml version="1.0" encoding="utf-8"?>
<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.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/appbarlt">
<android.support.v7.widget.Toolbar
android:id="#+id/my_toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary" />
</android.support.design.widget.AppBarLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:layout_below="#+id/appbarlt"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<android.support.v4.view.ViewPager
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
</RelativeLayout>

Give relation to your viewpager with appbar when using Relative Layout.
RelativeLayout is a view group that displays child views in relative positions. The position of each view can be specified as relative to sibling elements (such as to the left-of or below another view) or in positions relative to the parent RelativeLayout area (such as aligned to the bottom, left or center).
Try this code:
<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.design.widget.AppBarLayout
android:id="#+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.Toolbar
android:id="#+id/my_toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary" />
</android.support.design.widget.AppBarLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#+id/appbar"
android:orientation="vertical"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<android.support.v4.view.ViewPager
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
</RelativeLayout>

use this in below layout of Toolbar layout
android:layout_marginTop="?attr/actionBarSize"

How to use NestedScrollView, SwipeRefreshLayout and WebView together?

Using all the latest libraries. I have a simple WebView inside a CoordinatorLayout fragment. Trying to hide the toolbar when user scrolls sdown.
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/clRootHome"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="com.bytefury.deliverzz.fragment.HomeFragment">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_scrollFlags="scroll|enterAlways"
android:theme="#style/AppTheme.AppBarOverlay">
<include layout="#layout/toolbar" />
</android.support.design.widget.AppBarLayout>
<android.support.v4.widget.SwipeRefreshLayout
android:id="#+id/srlHome"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<android.support.v4.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<im.delight.android.webview.AdvancedWebView
android:id="#+id/frag_wv_wv"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbarStyle="insideOverlay" />
</android.support.v4.widget.NestedScrollView>
</android.support.v4.widget.SwipeRefreshLayout>
</android.support.design.widget.CoordinatorLayout>
However, this doesn't do anything at all. Swipe to refresh works fine.
Out of desperation, when I switch the NestedScrollView and SwipeRefreshLayout, I get a blank, white screen.

if you want your toolbar to be scrollable, refactor your layout into this
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:id="#+id/clRootHome"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="com.bytefury.deliverzz.fragment.HomeFragment">
<include layout="#layout/toolbar" />
<android.support.v4.widget.SwipeRefreshLayout
android:id="#+id/srlHome"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<im.delight.android.webview.AdvancedWebView
android:id="#+id/frag_wv_wv"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scrollbarStyle="insideOverlay" />
</android.support.v4.widget.SwipeRefreshLayout>
Now add this to your toolbar layout.
app:layout_scrollFlags="scroll|enterAlways"

set background for activity containing AppbBarLayout

I am trying to use androids CoordinatorLayout and FrameLayout. What I want to have is a
toolbar
LinearLayout showing some info
tablayout
listviews
when the listviews are scrolled the toolbar and the LinearLayouts should scrollup and hide and the tabs should go at the top.
I have a layout of the type:
<android.support.v4.widget.DrawerLayout
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:fitsSystemWindows="true">
<android.support.design.widget.CoordinatorLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/coordinatorLayout"
android:layout_height="match_parent"
android:layout_width="match_parent">
<android.support.design.widget.AppBarLayout
android:id="#+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<-- stuff I want to hide on scrolling -->
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_scrollFlags="scroll|enterAlways"
android:orientation="vertical">
<include
layout="#layout/toolbar"
app:layout_scrollFlags="scroll|enterAlways"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_scrollFlags="scroll|enterAlways"
android:orientation="vertical">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Gamercard content"
/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="More Gamercard content"
/>
</LinearLayout>
</LinearLayout>
<-- stuff I dont want to hide on scrolling -->
<android.support.design.widget.TabLayout
android:id="#+id/tabLayout"
android:scrollbars="horizontal"
android:layout_below="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
</android.support.design.widget.AppBarLayout>
<!-- My Scrollable View -->
<include layout="#layout/nested_scrolling_container_view"/>
</android.support.design.widget.CoordinatorLayout>
</android.support.v4.widget.DrawerLayout>
What I want to do is have a picture as the background for the entire activity, but what I see is that the AppBarLayout part is always dark. Please help.

I could do it programmatically by setting the backgroundColor in code to Color.TRANSPARENT.
appbar.setBackgroundColor(Color.TRANSPARENT);

Android app toolbar not hiding in scroll

Here is what I tried, the frame layout is fragment.. and that fragment displays a list on screen. when scrolling that list i want toolbar to hide... the code below is not working, what am i doing wrong. i am trying to follow tutorials
<?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"
android:fitsSystemWindows="true">
<android.support.v4.widget.DrawerLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical" >
<android.support.design.widget.AppBarLayout
android:id="#+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
android:fitsSystemWindows="true">
<android.support.v7.widget.Toolbar
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_scrollFlags="scroll|enterAlways"
android:background="#color/purple2"
android:minHeight="56dp"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:titleTextAppearance="#style/ToolbarTitle" >
</android.support.v7.widget.Toolbar>
</android.support.design.widget.AppBarLayout>
<FrameLayout
android:id="#+id/frame_container"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</LinearLayout>
<LinearLayout
android:id="#+id/line1"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="start"
android:fitsSystemWindows="true"
android:orientation="vertical" >
<ListView
android:id="#+id/list"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:divider="#null"
android:dividerHeight="0dp" />
< /LinearLayout>
</android.support.v4.widget.DrawerLayout>
</android.support.design.widget.CoordinatorLayout>

You are missing the indicator of what is the scroll to follow.
Add app:layout_behavior="#string/appbar_scrolling_view_behavior" to your ListView and everything should work.
* EDIT *
Upon further investigation I've discovered that basically the problem is the ListView. It doesn't implement NestedScrollingChild and hence the scrolling behaviour will not work.
The best you can do is transform that ListView into a RecyclerView with a LinearLayoutManager (which basically will look the same).
Other option is to add in Java code:
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
listView.setNestedScrollingEnabled(true);
}
but of course it will only work on Lollipop.