Develop Reference

Change insets for collapsing toolbar depending on its state

I have collapsing toolbar and some layout in it I want to collapse. To prevent view going under status bar, I use system insets to set margin for collapsing toolbar. I extracted AppBarLayout to separate file and included it inside CoordinatorLayout:
<com.google.android.material.appbar.AppBarLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/action_bar"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<com.google.android.material.appbar.CollapsingToolbarLayout
android:id="#+id/collapsing_toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#color/app_white"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?actionBarSize"
android:background="#color/colorToolbar"
android:elevation="4dp"
android:focusable="true"
android:focusableInTouchMode="true"
app:contentInsetStartWithNavigation="0dp"
app:layout_collapseMode="pin">
...
</androidx.appcompat.widget.Toolbar>
<com.google.android.material.card.MaterialCardView
android:id="#+id/bonuses_widget"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:cardCornerRadius="14dp"
app:cardElevation="3dp"
app:layout_collapseMode="parallax">
...
</com.google.android.material.card.MaterialCardView>
</com.google.android.material.appbar.CollapsingToolbarLayout>
</com.google.android.material.appbar.AppBarLayout>
Margins for MaterialCardView are set from code because layout doesn't support addition. I add margins for collapsing toolbar using insets:
ViewCompat.setOnApplyWindowInsetsListener(action_bar) { _, insets ->
collapsing_toolbar.setMarginTop(insets.systemWindowInsetTop)
insets
}
This works well when collapsing toolbar is expanded, but in collapsed state toolbar goes under status bar:
I have read this question, have implemented AppBarStateChangeListener and use it like this:
action_bar.addOnOffsetChangedListener(object : AppBarStateChangeListener() {
override fun onStateChanged(appBarLayout: AppBarLayout, state: State) {
if (state == State.COLLAPSED) {
ViewCompat.setOnApplyWindowInsetsListener(collapsing_toolbar) { _, insets ->
toolbar.setMarginTop(insets.systemWindowInsetTop)
insets
}
}
if (state == State.EXPANDED) {
ViewCompat.setOnApplyWindowInsetsListener(collapsing_toolbar) { _, insets ->
toolbar.setMarginTop(0)
insets
}
}
}
})
This didn't help, as I can understand so far, status bar's insets is already handled by action bar and collapsing toolbar has nothing to handle.
I also tried to margin to toolbar at the same time with collapsing toolbar, it worked but leaded to another problem:
After all I tried to remove insets and just set android:fitsSystemWindows="true" to action bar, this fixes problem with toolbar under status bar, but status bar unexpectedly gets strange color (purple) which isn't represented in app colors.
Hope someone knows hot to handle with insets properly in this case.

You can try calling the setSupportActionBar() in your Fragment, because that works for me:
(requireActivity() as AppCompatActivity).apply {
//supportActionBar?.hide() //may need this to hide the Activity actionBar
setSupportActionBar(binding.toolbar)
}
setHasOptionsMenu(true) //don't forget this
Demo: https://youtu.be/kmnsep_V-jE

Eventually I found suitable solution:
ViewCompat.setOnApplyWindowInsetsListener(action_bar) { view, insets ->
view.updatePadding(top = insets.systemWindowInsetTop)
insets
}
There is still problem with white background under status bar (I need it to be dark as on left screenshots), but initial problem is solved.

Button overlapping views on top of it

I made a custom view with a progress bar. To add it in all my fragments i made a base fragment. In the method onActivityCreated i added the following code:
activity?.run {
loading = LoadingView(this)
loading?.layoutParams = ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT)
loading?.visibility = View.GONE
(view as? ViewGroup)?.addView(loading)
}
And it works, but, when i make it visible, the buttons overlapped the progres bar in my LoadingView. So, when i show it i added brintToFront() method on a first test (that didnt work) and i saw i also had to use invalidate
protected fun showLoading() {
loading?.visibility = View.VISIBLE
loading?.bringToFront()
loading?.invalidate()
}
As this wasnt working either i started looking for a solution here and i found that the solution could be adding translationZ or elevation properties. So i tried to, but none is working.
The XML file of my view is:
<androidx.constraintlayout.widget.ConstraintLayout
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">
<ProgressBar
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:indeterminate="true"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
What am i doing wrong?

I've tried this and settings translationZ to 6f or more brings my view in front of buttons.
It seems that it should be set programmatically.
protected fun showLoading() {
loading?.translationZ = 6f
loading?.visibility = View.VISIBLE
}

BottomAppBar FabCradleMargin becoming less, almost flat, when BottomAppBar returns from being hidden

I am having an issue with my FabCradleMargin becoming less, almost flat, inside my Bottom App Bar when navigating through my app and scrolling up/down while hideonScroll is set to true. When the BottomAppBar hides from the screen, it returns resized under the Floating action Button. Must be a glitch in the new Android Material Components. Has anyone else been experiencing this issue. If so, what suggestions do you have to fixing it.
and
<com.google.android.material.bottomappbar.BottomAppBar
android:id="#+id/bar"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_gravity="bottom"
app:elevation="4dp"
app:fabAlignmentMode="center"
app:fabCradleRoundedCornerRadius="2dp"
app:hideOnScroll="true"
app:layout_scrollFlags="scroll|enterAlways"
app:navigationIcon="#drawable/ic_action_list" />
<com.google.android.material.floatingactionbutton.FloatingActionButton
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:backgroundTint="#color/blue500"
app:fabSize="normal"
app:layout_anchor="#+id/bar"
app:tint="#color/white"
app:layout_anchorGravity="right"
app:srcCompat="#drawable/ic_select_camera" />

I stumbled upon this problem as well. In my case it depended on the way I tried to hide the BottomAppBar and the FloatingActionButton. This is what I had first (Kotlin):
private fun showBottomNavigationBar(barVisibility: Boolean, fabVisibility: Boolean) {
navView.visibility = if (barVisibility) BottomAppBar.VISIBLE else BottomAppBar.GONE
fab.visibility = if (fabVisibility) FloatingActionButton.VISIBLE else FloatingActionButton.GONE
}
And this is what fixed it:
private fun showBottomNavigationBar(barVisibility: Boolean, fabVisibility: Boolean) {
navView.visibility = if (barVisibility) BottomAppBar.VISIBLE else BottomAppBar.GONE
if (fabVisibility) fab.show() else fab.hide()
}
So instead of hiding the FloatingActionButton with the visibility property, I used the hide() and show() methods of the FloatingActionButton.

Bottom Navigation with center button arc or hump [duplicate]

This question already has answers here:
New Bottom Layout from Google
(3 answers)
Closed 4 years ago.
Looking to modify the Bottom Navigation Bar with a main center action button which changes the shape of the navigation bar itself either an arc like so
or a hump in the bottom nav enveloping the center button around it.
I'm fine if I have to extend the BottomNavigationView but I don't know where to start.
I found this similar question, but it's not the exact problem I'm trying to solve.

Bro, try this
Just place the BottomAppBar and FloatingActionButton into parent CoordinatorLayout and set app:layout_anchor attribute of FloatingActionButton to reference id of BottomAppBar.
<android.support.design.bottomappbar.BottomAppBar
android:id="#+id/bottom_appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
app:theme="#style/ThemeOverlay.AppCompat.Dark.ActionBar"
app:popupTheme="#style/ThemeOverlay.AppCompat.Light"
app:fabAttached="true"
app:backgroundTint="#color/colorPrimary"
app:fabCradleVerticalOffset="12dp">
</android.support.design.bottomappbar.BottomAppBar>
<android.support.design.widget.FloatingActionButton
android:id="#+id/fab"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|center_horizontal"
android:src="#drawable/ic_add_white_24dp"
app:layout_anchor="#+id/bottom_appbar"/>
<FrameLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<android.support.design.button.MaterialButton
android:id="#+id/toggle_alignment"
android:layout_width="wrap_content"
android:layout_height="48dp"
android:layout_gravity="center"
android:textColor="#fff"
android:text="Toggle FAB alignment"
app:backgroundTint="#color/colorPrimary"/>
</FrameLayout>
To set menu options you can provide Menu resource to your BottomAppBar in code by calling BottomAppBar.replaceMenu(R.menu.xxx) and to toggle the alignment I created a simple extensions function
import kotlinx...bottom_appbar
import kotlinx...fab
import kotlinx...toggle_alignment
// using kotlin-android-extensions here for findViewById calls
class BottomAppBarActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.actvity_bottom_appbar)
//setSupportActionBar(bottom_appbar) calling this breaks it!
// setting the menu
bottom_appbar.replaceMenu(R.menu.bottom_appbar_menu)
toggle_alignment.setOnClickListener {
bottom_appbar.toggleAlignment()
}
}
fun BottomAppBar.toggleAlignment() {
val current = fabAlignmentMode
fabAlignmentMode = current.xor(1)
}
}

This type of Bottom App Bar comes with Support Library v28. This article by Joe Birch will be helpful.

AppBarLayout does not always re-enter on scroll down

I created a collapsing transparent search bar using AppBarLayout, CollapsingToolbarLayout inside a CoordinatorLayout and a RecyclerView. It was a bit (lot) tricky to have the recyclerView appear behind the appBarLayout instead of below it ; but is working. My problem is that sometimes, the app bar does not re-enter when I scroll down. I simply stays invisible outside of the screen. Here is my layout :
<android.support.design.widget.CoordinatorLayout
android:id="#+id/main_content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
app:expandedTitleMarginBottom="88dp">
<android.support.v7.widget.RecyclerView
android:id="#+id/services_recycler_view"
android:orientation="vertical"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_behavior="#string/appbar_scrolling_view_behavior"
app:behavior_overlapTop="88dp">
</android.support.v7.widget.RecyclerView>
<android.support.design.widget.AppBarLayout
android:id="#+id/appbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fitsSystemWindows="true"
android:background="#color/color_transparent"
app:elevation="0dp">
<android.support.design.widget.CollapsingToolbarLayout
android:id="#+id/collapsing_toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_scrollFlags="scroll|enterAlways"
android:fitsSystemWindows="false">
<Button
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Search Location or Service"
android:id="#+id/button_search_bar"/>
</android.support.design.widget.CollapsingToolbarLayout>
</android.support.design.widget.AppBarLayout>
</android.support.design.widget.CoordinatorLayout>
Any help on solving the not re-entering issue would be great.
A side problem, is that because I am using the app:behavior_overlapTop="88dp" to make recyclerView appear behind the app bar, the whole scrolling is a little odd : it starts by scrolling the appBar and then scrolls the recycler view. Any better solution is welcome.
EDIT :
I realized that the AppBar actually re-enter on scroll down but is invisible (I can click on it, I just can't see it). I figured I would share this new clue =)

It's not the answer i just want to confirmation that what you give, it will look like this?? on scroll up
means that Search button will come on top?
Edit:
<android.support.design.widget.CollapsingToolbarLayout
android:id="#+id/collapsing_toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fitsSystemWindows="false"
app:layout_scrollFlags="scroll|exitUntilCollapsed">
add exitUntilCollapsed flag.

After a few hours of trial and error I managed to find a solution to your problem. You can set an OnScrollListener to your RecyclerView. Inside the listener you check if in onScrolled the first item of the RecyclerView is on screen.
If the first item is visible, first you change the visibility of your AppBarLayout to View.INVISIBLE and secondly you change it directly back to View.VISIBLE.
Your code may look like this (Kotlin) :
override fun onCreate(savedInstanceState : Bundle?) {
super.onCreate(savedInstanceState)
contentView(R.layout.my_activity)
val mAppbar = appbar
val mServices_recycler_view = services_recycler_view
//...
mServices_recycler_view.addOnScrollListener(object : RecyclerView.OnScrollListener() {
override fun onScrollStateChanged(recyclerView : RecyclerView, newState : Int) {
super.onScrollStateChanged(recyclerView, newState)
}
override fun onScrolled(recyclerView : RecyclerView, dx : Int, dy : Int) {
val layoutManager = LinearLayoutManager::class.java.cast(recyclerView.layoutManager)
if(layoutManager.findFirstVisibleItemPosition() == 0) {
mAppbar.visibility = View.INVISIBLE
mAppbar.visibility = View.VISIBLE
}
}
}
I am aware of the fact, that this is not very beautiful, but as long as it solves the issue I don't mind.
Additionally you want to improve the check if the first item of the RecyclerView is shown, so that it won't trigger everytime you scroll, even when it is only a little bit.
The layout you described in your question does not have to be changed.