I have this scenario :
I’ve created this
<style name="Title.Collapsed" parent="android:TextAppearance">
<item name="android:textColor">@android:color/white</item>
<item name="android:textSize">18sp</item>
</style>
<style name="Title.Expanded" parent="android:TextAppearance">
<item name="android:textColor">@android:color/white</item>
<item name="android:textSize">28sp</item>
</style>
Then here’s my layout
<?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="match_parent">
<com.google.android.material.appbar.AppBarLayout
android:id="@+id/appBarLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@android:color/transparent"
android:fitsSystemWindows="true"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light">
<com.google.android.material.appbar.CollapsingToolbarLayout
android:id="@+id/collapsingToolbar"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
app:collapsedTitleGravity="end"
app:collapsedTitleTextAppearance="@style/Title.Collapsed"
app:expandedTitleGravity="end"
app:expandedTitleMarginEnd="64dp"
app:expandedTitleMarginStart="48dp"
app:expandedTitleTextAppearance="@style/Title.Expanded"
app:layout_scrollFlags="scroll|exitUntilCollapsed|snap">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="40dp"
android:background="@android:color/transparent"
android:gravity="end"
android:orientation="vertical"
android:padding="10dp"
app:layout_collapseMode="parallax">
<TextView
android:id="@+id/tv_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hi"
android:textSize="28sp" />
</LinearLayout>
<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@color/design_default_color_primary"
app:layout_collapseMode="pin"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
</com.google.android.material.appbar.CollapsingToolbarLayout>
</com.google.android.material.appbar.AppBarLayout>
<androidx.core.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintTop_toBottomOf="@+id/appBarlayout">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/long_text" />
</androidx.core.widget.NestedScrollView>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
Then I’m doing the collapsing animation as :
val collapsingToolbar = findViewById<CollapsingToolbarLayout>(R.id.collapsingToolbar)
collapsingToolbar.title = ""
title = ""
val appBarLayout = findViewById<AppBarLayout>(R.id.appBarLayout)
appBarLayout.addOnOffsetChangedListener(object : OnOffsetChangedListener {
var isShow = false
var scrollRange = -1
override fun onOffsetChanged(appBarLayout: AppBarLayout, verticalOffset: Int) {
if (scrollRange == -1) {
scrollRange = appBarLayout.totalScrollRange
}
if (scrollRange + verticalOffset == 0) {
//when collapsingToolbar at that time display actionbar title
collapsingToolbar.title = "Hi"
isShow = true
} else if (isShow) {
collapsingToolbar.title = ""
isShow = false
}
}
})
It works flawless, the problem is now that I want to add a sticky button but I can not tell to NestedScrollView to be aligned bottomToTopOf my button because it’s not inside a ConstraintLayout neither it’s a child of it, so it doesn’t crash in terms of compiling but the button hides the last part of the scrollView… I’ve tried to add marginBottom="buttonSize" and in the layout design it looks good, but when compiling it doesn’t do the collapsing animation because I’ve added the marginBottom. How can I fix this? I need this NestedScrollView to be not height match_parent even if it’s wrap_content it’s aligned to the parent and the button is overlapped.
Advertisement
Answer
You can wrap the CoordinatorLayout & the bottom Button inside a ConstraintLayout as the root layout; now the CoordinatorLayout can be constraint to the top of the button instead of having a height that equals to the entire screen height.
So, the layout would be:
<ConstraintLayout>
<CoordinatorLayout>
<AppBarLayout>
<CollapsingToolbarLayout>
<NestedScrollView>
</CoordinatorLayout>
<Button/>
</ConstraintLayout>
Applying to your layout:
<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">
<androidx.coordinatorlayout.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="0dp"
app:layout_constraintBottom_toTopOf="@+id/button"
app:layout_constraintTop_toTopOf="parent">
<com.google.android.material.appbar.AppBarLayout
android:id="@+id/appBarLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="@android:color/transparent"
android:fitsSystemWindows="true"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light">
<com.google.android.material.appbar.CollapsingToolbarLayout
android:id="@+id/collapsingToolbar"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:fitsSystemWindows="true"
app:collapsedTitleGravity="end"
app:collapsedTitleTextAppearance="@style/Title.Collapsed"
app:expandedTitleGravity="end"
app:expandedTitleMarginEnd="64dp"
app:expandedTitleMarginStart="48dp"
app:expandedTitleTextAppearance="@style/Title.Expanded"
app:layout_scrollFlags="scroll|exitUntilCollapsed|snap">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="40dp"
android:background="@android:color/transparent"
android:gravity="end"
android:orientation="vertical"
android:padding="10dp"
app:layout_collapseMode="parallax">
<TextView
android:id="@+id/tv_title"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Hi"
android:textSize="28sp" />
</LinearLayout>
<androidx.appcompat.widget.Toolbar
android:id="@+id/toolbar"
android:layout_width="match_parent"
android:layout_height="?attr/actionBarSize"
android:background="@color/design_default_color_primary"
app:layout_collapseMode="pin"
app:popupTheme="@style/ThemeOverlay.AppCompat.Light" />
</com.google.android.material.appbar.CollapsingToolbarLayout>
</com.google.android.material.appbar.AppBarLayout>
<androidx.core.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_behavior="@string/appbar_scrolling_view_behavior">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/long_text" />
</androidx.core.widget.NestedScrollView>
</androidx.coordinatorlayout.widget.CoordinatorLayout>
<Button
android:id="@+id/button"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:insetLeft="0dp"
android:text="OK"
android:insetTop="0dp"
android:insetRight="0dp"
android:insetBottom="0dp"
app:layout_constraintBottom_toBottomOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>