Develop Reference

Buttons not clickable in the upper half

The following buttons display_current_month and display_current_year in a fragment nested in coordinator layout are not clickable in the upper half.
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/activity_custom_calendar"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="10dp">
<Button
android:id="#+id/display_current_month"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="15dp"/>
<Button
android:id="#+id/display_current_year"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toEndOf="#id/display_current_month"
android:layout_marginTop="15dp"/>
<LinearLayout
android:id="#+id/calendar_days_of_week"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#id/display_current_month"
android:orientation="horizontal">
</LinearLayout>
</RelativeLayout>
The coordinator layout :
<android.support.design.widget.AppBarLayout
android:id="#+id/reminders_app_bar_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#drawable/shape_rounded_rectangle">
<android.support.design.widget.CollapsingToolbarLayout
android:id="#+id/reminders_collapsing_toolbar_layout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:contentScrim="?attr/colorPrimary"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<android.support.v4.view.ViewPager
android:id="#+id/calendar_view"
android:layout_width="match_parent"
android:layout_height="380dp"
android:layout_margin="5dp"
app:layout_collapseMode="parallax" />
<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/ThemeOverlay.AppCompat.Light" />
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
Attached screenshot with actual buttons. Any help is much appreciated.
P.S. The buttons seem to have a bottom padding, which allows the buttons to be clicked with ~ 10 dp below their border.

your view pager is located under your toolbar, that's why you can't click on your buttons and your toolbar will get your screen's touchs.
you can put below code inside your ViewPager tag in your xml.
android:layout_marginTop="?android:attr/actionBarSize"

By default buttons are clickable and should get click events callback in java file as well untill you are not setting clickListener dynamically to null.

How to put RecyclerView below Toolbar and above TabLayout and ViewPager also handling responses to scrolls in a custom manner?

I want to create a layout like the below image:
A CoordinatorLayout which contain :
CollapsingToolbarLayout( contain ImageView & Toolbar)
RecyclerView
TabLayout
ViewPager( that each fragment of it contain a RecyclerView)
I wanna responding to scroll events in this way:
CollapsingToolbarLayout expand and collapse by scrolling
Toolbar sticks to the top until TabLayout reach to the top
After that toolbar scroll up and TabLayout stick to the top
I'm having trouble with the RecyclerView between CollapsingToolbarLayout and TabLayout. I can implement this layout without that RecyclerView( I put CollapsingToolbarLayout and TabLayout inside the AppBarLayout and the ViewPager outside it, inside the CoordinatorLayout).
My Question:
Where should I put that RecyclerView?
Which & where layout_scrollFlags and layout_behavior should I set for each layouts?
It seems that AppBarLayout have a limited height. When I put the RecyclerView inside AppBarLayout, only a portion part of the RecyclerView is visible and also TabLayout disappear.
I read lots of tutorials like this one and lots of questions like this one and this one, but non of them help me.

use this as a main layout
activity_main
<?xml version="1.0" encoding="utf-8"?>
<android.support.v4.widget.SwipeRefreshLayout 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/swipe_refresh_layout_profile"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:ignore="RtlHardcoded">
<android.support.design.widget.CoordinatorLayout
android:id="#+id/co_profile_activity_root_layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/white"
android:visibility="visible">
<android.support.design.widget.AppBarLayout
android:id="#+id/appbar_profile"
android:layout_width="match_parent"
android:layout_height="#dimen/profile_img_placeholder_height"
android:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar">
<android.support.design.widget.CollapsingToolbarLayout
android:id="#+id/collapse_toolbar_profile"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_scrollFlags="scroll|exitUntilCollapsed|snap">
<RelativeLayout
android:id="#+id/rel_top"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop">
<ImageView
android:id="#+id/img_bg_placeholder_profile"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"
android:tint="#11000000"
app:layout_collapseMode="parallax"
app:layout_collapseParallaxMultiplier="0.9" />
<LinearLayout
android:id="#+id/lin_top_inner"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#BF473e6b"
android:orientation="vertical"
android:scaleType="centerCrop">
</LinearLayout>
</RelativeLayout>
<FrameLayout
android:id="#+id/frame_detail_profile"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="center|center_horizontal"
android:orientation="vertical"
app:layout_collapseMode="parallax"
app:layout_collapseParallaxMultiplier="0.3">
<android.support.v7.widget.RecyclerView
android:layout_width="wrap_content"
android:layout_height="wrap_content">
</android.support.v7.widget.RecyclerView>
</FrameLayout>
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar_profile"
android:layout_width="match_parent"
android:layout_height="#dimen/profile_toolbar_height"
android:gravity="top|center"
app:layout_anchor="#id/frame_detail_profile"
app:layout_collapseMode="pin"
app:theme="#style/ThemeOverlay.AppCompat.Dark"
app:title="">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">
<TextView
android:id="#+id/tv_toolbar_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginLeft="#dimen/profile_toolbar_title_left_margin"
android:gravity="center_vertical|center"
android:ellipsize="end"
android:singleLine="true"
android:layout_gravity="center"
android:textColor="#android:color/white"
android:textSize="20sp" />
</LinearLayout>
</android.support.v7.widget.Toolbar>
<android.support.design.widget.TabLayout
android:id="#+id/tab_layout_profile"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:layout_gravity="bottom"
android:layout_marginTop="#dimen/profile_tab_layout_top_margin"
android:background="#color/white"
app:tabIndicatorColor="#color/colorPrimary"
app:tabSelectedTextColor="#color/colorPrimary"
app:tabTextColor="#color/charcoal_grey" />
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.v4.view.ViewPager
android:id="#+id/view_pager_profile"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
</android.support.design.widget.CoordinatorLayout>
</RelativeLayout>
</android.support.v4.widget.SwipeRefreshLayout>
and for grid layout of tabs use adapter classes.

Start with AppBarLayout under which you add CollapsingToolbarLayout with scrollFlags="scroll|exitUntilCollapsed",
add LinearLayout with vertical orientation to CollapsingToolbarLayout and add the
FrameLayout with ImageView + Toolbar
RecyclerView
TabLayout

Two things to be done:-
When the search button is clicked, set the visibility of recycler view to VISIBLE
When the back button is pressed, set the visibility of recycler view to GONE
Following are the implementations:
1. Setting the visibility of recycler view to VISIBLE:
public boolean onOptionsItemSelected(MenuItem item) {
if (item.getItemId() == R.id.searchView) {
rView.setVisibility(VISIBLE);
}
return true;
}
2. Setting the visibility of recycle adapter to GONE
MenuItem searchMenuItem = menu.findItem(R.id.searchView);
MenuItemCompat.setOnActionExpandListener(searchMenuItem, new MenuItemCompat.OnActionExpandListener() {
#Override
public boolean onMenuItemActionExpand(MenuItem item) {
return true;
}
#Override
public boolean onMenuItemActionCollapse(MenuItem item) {
recyclerView.setVisibility(GONE);
return true;
}
});
NOTE: Do not forget to keep the visibilty as GONE initially when the activity is started

I know I might be late to this answer but I have also been trying to implement this for a while. The solution I have feels a bit hacky but it is an option for trying to get the tabs to stick. In a simpler solution lets say we wanted the following:
A Collapsing toolbar layout
Which links to a scroll view.
In that scroll view we want the following:
A recyclerview that say scrolls horizontally
Below the recycler view a tab layout
Below the tab layout we want a view pager that will load dynamic fragments within a fixed space.
activity_scrolling.xml the outer parent xml file may look something like this
<?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"
android:fitsSystemWindows="true"
tools:context=".temp.ScrollingActivity">
<com.google.android.material.appbar.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">
<com.google.android.material.appbar.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"
app:toolbarId="#+id/toolbar">
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:layout_marginBottom="5dp"
app:layout_collapseMode="pin"
app:popupTheme="#style/AppTheme.PopupOverlay" />
</com.google.android.material.appbar.CollapsingToolbarLayout>
</com.google.android.material.appbar.AppBarLayout>
<include layout="#layout/content_scrolling" />
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="#dimen/fab_margin"
app:layout_anchor="#id/app_bar"
app:layout_anchorGravity="bottom|end"
app:srcCompat="#android:drawable/ic_dialog_email" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
Then the inner content_scrolling.xml may look something like this
<?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"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
tools:context=".temp.ScrollingActivity"
tools:showIn="#layout/activity_scrolling">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="5dp"
android:layout_marginTop="20dp"
android:layout_marginEnd="20dp"
android:gravity="center"
android:text="A Heading"
android:textSize="#dimen/text_xl"
android:textStyle="bold" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recycler_view"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#id/title" />
<com.google.android.material.tabs.TabLayout
android:id="#+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#id/recycler_view"
android:layout_gravity="center"
android:minHeight="60dp"
app:tabGravity="fill"
app:tabIndicatorColor="#color/colorAccent"
app:tabMode="fixed"
app:tabSelectedTextColor="#color/colorPrimaryDark" />
<androidx.viewpager.widget.ViewPager
android:id="#+id/view_pager"
android:layout_width="match_parent"
android:layout_height="680dp"
android:layout_below="#+id/tabs" />
</RelativeLayout>
</androidx.core.widget.NestedScrollView>
This will allow you to forcefully place the tab layout in a location of your choosing (even if its after a recyler view).
The hacky part which i dont like is this specific line android:layout_height="680dp" which forces the viewpager height to be something specific. I am not sure why wrap_content or match_parent do not work. But this is the best thing to a solution I can provide for the issue of placing TabLayout and ViewPager in specific places.

Somebody can explain how works AppBarLayout and CollapsingToolbarLayout?

I'm trying to make something like the image posted, but that suppose the viewpager is scrollable with the recyclerView, the header is a simple Linear/Relative Layout and this will be static, the fab same (not scrollable) but is not working.
I posted my layout below
<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">
<include layout="#layout/layout_view_pager"
app:layout_collapseMode="parallax"
app:layout_behavior="#string/appbar_scrolling_view_behavior"/>
<android.support.v7.widget.RecyclerView
android:id="#+id/list"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipToPadding="true"
android:saveEnabled="false"
app:layout_behavior="#string/appbar_scrolling_view_behavior" />
<android.support.design.widget.AppBarLayout
android:id="#+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fitsSystemWindows="true"
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="wrap_content"
android:fitsSystemWindows="true"
app:contentScrim="?attr/colorPrimary"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<RelativeLayout
android:id="#+id/header_labels"
android:layout_width="match_parent"
android:layout_height="#dimen/header_height"
android:background="#color/brand_green"
app:layout_collapseMode="pin"
android:orientation="vertical">
<TextView
android:id="#+id/actionbar_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:textColor="#android:color/white"
android:textSize="43sp"/>
<TextView
android:id="#+id/actionbar_balance_label"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:layout_marginTop="5dp" android:textSize="13sp"/>
</RelativeLayout>
<android.support.v7.widget.Toolbar
android:id="#+id/my_toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
app:layout_collapseMode="pin"
app:contentInsetStart="0dp">
<TextView
android:id="#+id/chime_sign"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
app:iconFontColor="#android:color/white"
app:iconFontSize="26sp"/>
</android.support.v7.widget.Toolbar>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:clickable="true"
android:src="#drawable/fab_icon_mm"
app:elevation="6dp"
app:fabSize="normal"
app:rippleColor="#color/brand_dark_green"
app:pressedTranslationZ="12dp"
app:layout_anchor="#id/header_labels"
app:layout_anchorGravity="bottom|right|end"/>

Firstly, you've set app:layout_collapseMode to pin for both RelativeLayout and Toolbar which will not show any effect. Setting app:layout_collapseMode to pin for any view will not change the view's height when scrolling takes place. To change a view's height when scrolling takes place, you need to set app:layout_collapseMode to parallax.
Secondly, set a specified height for your AppBarLayout. Setting WRAP_CONTENT will not work properly. You need to set specific dimensions like 180dp.
Thirdly, according to your question you wanted the Viewpager to be scrollable with the RecyclerView. Your code doesn't work the way you intended it to be. If you want the ViewPager to be scrollable with RecyclerView then you need to remove the RecyclerView from the xml code and add it to a separate xml code file. Then you need to create a Fragment or two (according to your need), add the Fragment in the ViewPager and instantiate the RecyclerView in there. This Fragment will also be responsible for inflating data in the RecyclerView.

Where do I put my own xml code in activity_main using Androids default tab application

This is the activity_main.xml layout for Androids default tab application:
<?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:id="#+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
tools:context=".activities.MainActivity">
<android.support.design.widget.AppBarLayout
android:id="#+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingTop="#dimen/appbar_padding_top"
android:theme="#style/AppTheme.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.PopupOverlay">
</android.support.v7.widget.Toolbar>
<android.support.design.widget.TabLayout
android:id="#+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content" />
</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"/>
<!-- When I add my own view here and use match_parent, it fills ENTIRE screen, even over the Toolbar. The ViewPager right above does not do this. Why? -->
</android.support.design.widget.CoordinatorLayout>
I am trying to add my own buttons/textviews/etc to my activity_main.xml but I do not know where to add them. The android.support.v4.view.ViewPager uses match_parent although it does not fit the whole screen, it expands across the entire screen besides the Toolbar area at the top. However, whenever I add my own view underneath the android.support.v4.view.ViewPager, lets say RelativeView and set it to match_parent, it expands OVER the Toolbar. This led me to believe that I should put my contents inside the ViewPager tags but that does not work either.
Where should I put my views so that they are not overlapping the Toolbar?

You can wrap your ViewPager in an RelativeLayout and you can add the view child also.
Here is the code snippet which may help you-
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/colorAccent"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<Button
android:id="#+id/button"
android:layout_width="match_parent"
android:layout_height="48dp"
android:text="I am clickable" />
<android.support.v4.view.ViewPager
android:id="#+id/container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_alignParentEnd="true"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:layout_alignParentStart="true"
android:layout_below="#+id/button"
android:background="#color/colorNeutral"
android:layout_above="#+id/button2" />
<Button
android:layout_marginBottom="56dp"
android:layout_alignParentBottom="true"
android:id="#+id/button2"
android:layout_width="match_parent"
android:layout_height="48dp"
android:text="I am clickable too" />
</RelativeLayout>

Set layout below navigationBar in coordinatorLayout android

The question is simple: How to set (any) layout bellow navigation bar in a coordinatorLayout?
If I use a frameLayout in a RelativeLayout, the RelativeLayout height fill the whole screen include the navigationBar.
Here is my code:
<RelativeLayout
android:id="#+id/drawer_container"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="false"
app:layout_behavior="#string/appbar_scrolling_view_behavior">
<FrameLayout
android:id="#+id/frameLayout"
android:layout_width="match_parent"
android:layout_height="match_parent" />
</RelativeLayout>
<android.support.design.widget.AppBarLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">
<android.support.v7.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?android:attr/actionBarSize"
android:background="#color/primary"
app:layout_scrollFlags="scroll|enterAlways"
android:minHeight="?android:attr/actionBarSize"
app:popupTheme="#style/MaterialDrawerTheme.Light.DarkToolbar"
app:theme="#style/ToolbarTheme">
<TextView
android:id="#+id/toolbar_title"
style="#style/TextAppearance.AppCompat.Widget.ActionBar.Title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerVertical="true"
android:gravity="center"
android:textColor="#color/icons" />
</android.support.v7.widget.Toolbar>
</android.support.design.widget.AppBarLayout>
And the problem (after I added a fragment the frameLayout):
image 1
And the Android Studio preview screen:
image 2
(Sorry for the images, currently i haven't got enough repulation to post directly here :( )

Change android:fitsSystemWindows to false:
android:fitsSystemWindows="false"