Develop Reference

White space on top of ViewPager in CoordinatorLayout

In the main layout, I have a coordinatorLayout and its children are appbarLayout and viewPager.
In each page of the viewPager, I have a fragment, that either it has a nestedScrollview or a recyclerview.
My problem is that there is a white space on top of all the fragments in each page of the viewPager.
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="fill_vertical"
android:id="#+id/konta">
<android.support.design.widget.AppBarLayout
android:id="#+id/smooth_app_bar_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/blue_200"
android:minHeight="#dimen/mdSecondaryActionBarSize">
<android.support.design.widget.CollapsingToolbarLayout
android:id="#+id/collapsing_toolbar_layout"
android:layout_width="match_parent"
android:layout_height="#dimen/app_bar_height"
app:titleEnabled="false"
app:layout_collapseMode="parallax"
android:background="#android:color/transparent"
app:layout_scrollFlags="scroll|snap">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="#dimen/toolbar_height"
android:background="#android:color/transparent"
app:layout_collapseMode="pin"
app:layout_scrollFlags="scroll|enterAlways"
app:navigationIcon="#drawable/ic_arrow_right" />
</android.support.design.widget.CollapsingToolbarLayout>
<android.support.design.widget.TabLayout
android:layoutDirection="ltr"
tools:targetApi="jelly_bean_mr1"
android:id="#+id/tab_layout"
android:layout_width="match_parent"
android:layout_height="#dimen/tab_size"
android:background="#android:color/transparent"
app:tabIndicatorColor="#android:color/white" />
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/view_pager"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_gravity="fill_vertical"
android:fitsSystemWindows="true"
app:layout_behavior="#string/appbar_scrolling_view_behavior"/>
</android.support.design.widget.CoordinatorLayout>

You should try this in your XML file:
android:layout_marginStart="0dp"

How to scroll and collapse a LinearLayout with Toolbar in Coordinator Layout

I'm trying to accomplish a scrolling behavior with coordinator layout in my application.
I've the following layout structure for the activity.
<android.support.design.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="match_parent"
android:fitsSystemWindows="true">
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:theme="#style/AppTheme.Dark.AppBarOverlay">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_scrollFlags="scroll|enterAlways"
app:popupTheme="#style/AppTheme.Dark.PopupOverlay"/>
</android.support.design.widget.AppBarLayout>
<!-- The layout to be collapse with toolbar -->
<LinearLayout
android:id="#+id/ll_collapse_container"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
</LinearLayout>
<android.support.v7.widget.RecyclerView
android:id="#+id/rv_list"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"/>
</android.support.design.widget.CoordinatorLayout>
When I scroll up the recycler view items the toolbar collapses and goes up out of the window and when I scroll down I get the toolbar back.
Is it possible to collapse the LinearLayout with toolbar when I scroll the Recycler View?

<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context="in.test.ProfileActivity">
<android.support.design.widget.AppBarLayout
android:id="#+id/app_bar"
android:layout_width="match_parent"
android:layout_height="#dimen/app_bar_height"
android:fitsSystemWindows="true"
android:theme="#style/AppTheme.AppBarOverlay">
<android.support.design.widget.CollapsingToolbarLayout
android:id="#+id/toolbar_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
app:contentScrim="?attr/colorPrimary"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<LinearLayout
android:id="#+id/ll_collapse_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_collapseMode="parallax"
android:orientation="horizontal"></LinearLayout>
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_collapseMode="pin"
app:popupTheme="#style/AppTheme.PopupOverlay" />
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v7.widget.RecyclerView
android:id="#+id/rv_list"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"/>
</android.support.design.widget.CoordinatorLayout>

ExpandableListView not working properly

I am implementing an app with ExpandableListview, Fragment, Viewpager and CollapsingToolbarLayout.
But I have a problem. My ExpandableListview has a wrong behavior. The remaining items below are cut. And when I click on an item below the top item displayed behind TabLayout.
What is my error in the code? Thank you
main.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:fitsSystemWindows="true"
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:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
android:fitsSystemWindows="true">
<android.support.design.widget.CollapsingToolbarLayout
android:id="#+id/collapsing_toolbar"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
app:expandedTitleMarginStart="30dp"
app:expandedTitleMarginEnd="25dp"
app:expandedTitleTextAppearance="#style/HeaderTitleStyle"
app:contentScrim="?attr/colorPrimary"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<ImageView
android:id="#+id/background"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:adjustViewBounds="true"
android:fitsSystemWindows="true"
app:layout_collapseMode="parallax"
android:src="#drawable/img_oficinas"/>
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:minHeight="?attr/actionBarSize"
android:background="#android:color/transparent"
app:theme="#style/ToolbarColoredBackArrow"
app:layout_collapseMode="pin"/>
</android.support.design.widget.CollapsingToolbarLayout>
<android.support.design.widget.TabLayout
android:id="#+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:background="#color/colorAccent"
app:tabTextColor="#color/tabs_text_selector"
app:tabIndicatorHeight="3dp"
app:tabIndicatorColor="#android:color/white"/>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"/>
</android.support.design.widget.CoordinatorLayout>
fragment.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.NestedScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fillViewport="true">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ExpandableListView
android:id="#+id/expandableListView"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:groupIndicator="#null"
android:background="#android:color/white"
android:dividerHeight="0dp"
android:divider="#android:color/white" />
</LinearLayout>
</android.support.v4.widget.NestedScrollView>

CoordinatorLayout's ScrollingViewBehavior only works with views that support nested scrolling (exp RecyclerView).
ExpandableListView does not support it by default, so the CoordinatorLayout is not handling the position of the ExpandableListView correctly.
For API >21 you can obtain this behavior by:
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
setNestedScrollingEnabled(true);
}
Otherwise you can switch to a custom RecyclerView or ExpandableRecyclerView.

Toolbar collapse on scroll with Drawer Layout, Coordinator Layout, and Fragments

I'm trying to get the toolbar to collapse on scroll, but no matter what answer I follow I cannot seem to get it to collapse on scroll. The fragment that gets inflated in the FrameLayout is a View Pager if that makes a difference. Any help would be greatly appreciated.
<android.support.v4.widget.DrawerLayout 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/drawer_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.bluecadet.android.nasm.MainActivity">
<android.support.design.widget.CoordinatorLayout
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"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/toolbar"
app:layout_scrollFlags="scroll|enterAlways"
android:background="#color/primary"
>
<ImageView
android:layout_width="32dp"
android:layout_height="32dp"
android:src="#drawable/home"
/>
</android.support.v7.widget.Toolbar>
</android.support.design.widget.AppBarLayout>
<FrameLayout
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
/>
</android.support.design.widget.CoordinatorLayout>
<fragment android:id="#+id/navigation_drawer"
android:layout_width="#dimen/navigation_drawer_width"
android:layout_height="match_parent"
android:layout_gravity="start"
android:name="com.bluecadet.android.nasm.ui.NavigationDrawerFragment"
tools:layout="#layout/fragment_navigation_drawer" />
</android.support.v4.widget.DrawerLayout>

Well i am not talking about any thrid party library, it is included support design library. Your toolbar and image view have to be in CollapsingToolBarLayout
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<android.support.v7.widget.RecyclerView
android:id="#+id/recycler"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="256dp"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.design.widget.CollapsingToolbarLayout
android:id="#+id/collapsingToolbarLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:contentScrim="?attr/colorPrimaryDark"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<ImageView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scaleType="centerCrop"
android:src="#drawable/abcd"
app:layout_collapseMode="parallax"
app:layout_collapseParallaxMultiplier="0.7" />
<android.support.v7.widget.Toolbar
android:id="#+id/mtool"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="?attr/colorPrimary"
app:layout_collapseMode="pin"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"
app:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
</android.support.v7.widget.Toolbar>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>

How to use scrollbar and fast Scroll to NestedScrollView

I'm using NestedScrollView with Coordinator layout.
<?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.CoordinatorLayout
android:id="#+id/coordinator_layout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<...AppBarLayout
android:id="#+id/appBar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
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:toolbarId="#+id/toolbar"
app:contentScrim="#color/my_primary"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<include
layout="#layout/calendar_view"/>
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"
app:layout_collapseMode="pin" />
</android.support.design.widget.CollapsingToolbarLayout>
</...AppBarLayout>
<android.support.v4.widget.NestedScrollView
android:id="#+id/nestedScrollView"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<FrameLayout
android:id="#+id/frame_layout_2"
android:layout_width="match_parent"
android:layout_height="match_parent"/>
</android.support.v4.widget.NestedScrollView>
</android.support.design.widget.CoordinatorLayout>
</RelativeLayout>
I want to add a scroll bar to drag the scroll view using it (Fast Scroll). It looks like NestedScrollView doesn't have fastScroll attribute.
I tried adding
android:scrollbars="vertical"
android:fadeScrollbars="false"
android:fastScrollEnabled="true"
android:fastScrollAlwaysVisible="true"
All of this didn't Work.