TransitionManager.beginDelayedTransition doesn't animate when activity first loads - android

I am using the constraintLayout with animations using TransitionManager.
I have the following 2 layouts
This is my main_activity.xml
<android.support.constraint.ConstraintLayout
android:id="#+id/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">
<ImageView
android:id="#+id/image"
android:layout_width="0dp"
android:layout_height="160dp"
android:background="#color/colorPrimary"
app:layout_constraintTop_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"/>
<Button
android:id="#+id/btn"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent"
android:text="Let's start animating"/>
</android.support.constraint.ConstraintLayout>
And this is my main_activity_alt.xml
<android.support.constraint.ConstraintLayout
android:id="#+id/constraintLayout"
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto">
<ImageView
android:id="#+id/image"
android:layout_width="0dp"
android:layout_height="160dp"
android:background="#color/colorPrimary"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"/>
<Button
android:id="#+id/btn"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent"
android:text="Let's start animating"/>
</android.support.constraint.ConstraintLayout>
In my MainActivity I want to animate the image to slide upwards which would be the main_activity_alt.xml
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val constraintSet1 = ConstraintSet()
constraintSet1.clone(constraintLayout)
val constraintSet2 = ConstraintSet()
constraintSet2.clone(this, R.layout.activity_main_alt)
val transition = ChangeBounds()
transition.duration = 5000
val handler = Handler()
handler.postDelayed({
TransitionManager.beginDelayedTransition(constraintLayout, transition)
constraintSet2.applyTo(constraintLayout)
}, 10)
}
When the above starts the image is already displayed. The main_activity.xml should hide and the main_activity_alt.xml will be its final resting place.
However, when the screens loads it just immediately displays the imageview without any animation
Anything I am doing wrong with the above?

From the documentation for beginDelayedTransition:
Calling this method causes TransitionManager to capture current values in the scene root and then post a request to run a transition on the next frame. At that time, the new values in the scene root will be captured and changes will be animated.
You will have to wait until the layout is laid out before attempting the transition. There are a number of ways to do this, but the easiest would be to post the transition code as follows:
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val constraintLayout = findViewById<ConstraintLayout>(R.id.constraintLayout)
constraintLayout.post {
val constraintSet1 = ConstraintSet()
constraintSet1.clone(constraintLayout)
val constraintSet2 = ConstraintSet()
constraintSet2.clone(this, R.layout.activity_main2_alt)
val transition = ChangeBounds()
transition.duration = 5000
TransitionManager.beginDelayedTransition(constraintLayout, transition)
constraintSet2.applyTo(constraintLayout)
}
}

Try to make a delay to your transition so first layout would be inflated when transition starts
transition.delay = 300
if this wont work then try
Handler().postDelayed({do transition here}, 300)

Related

Why does pressing the button crash my app? [closed]

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Edit the question to include desired behavior, a specific problem or error, and the shortest code necessary to reproduce the problem. This will help others answer the question.
Closed 1 year ago.
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I'm trying to get a popup to show up when I press a button. I wanted to make sure it even shows up before working on the details but the app just crashes when i press it. The commented block is what I originally intended the button to do (just adding an item to the recyclerview) but I decided I wanted to do something a bit different. It only had the problem of crashing when I started adding the popup window stuff. The app still runs fine even if I remove the popup window stuff and leave the commented block commented out. So I don't know if the listadapter class is relevant but ill just include it.
MainActivity.kt
class MainActivity : AppCompatActivity() {
private lateinit var listAdapter: ListAdapter
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
listAdapter = ListAdapter(mutableListOf())
recyclerView.adapter = listAdapter
recyclerView.layoutManager = LinearLayoutManager(this)
btn_add.setOnClickListener {
/*
//get text from textbox
val itemText = et_reminder.text.toString()
if (itemText.isNotEmpty()){
//create item with text
val item = Item (itemText)
//add to list
listAdapter.addItem((item))
//clear textbox
et_reminder.text.clear()
}*/
val view : View = LayoutInflater.from(applicationContext).inflate (R.layout.popup_s,null)
val popup: PopupWindow = PopupWindow(view, 250, 250,true)
popup.showAtLocation(view, Gravity.NO_GRAVITY, 0,0)
}
}
}
ListAdapter.kt
class ListAdapter(
private val items: MutableList<Item>
): RecyclerView.Adapter<ListAdapter.ListViewHolder>()
{
class ListViewHolder(itemView: View):RecyclerView.ViewHolder(itemView)
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ListViewHolder {
val itemView: View =
LayoutInflater.from(parent.context).inflate (R.layout.list_item, parent, false)
return ListViewHolder(itemView)
}
override fun onBindViewHolder(holder: ListViewHolder, position: Int) {
val curr_item = items [position]
holder.itemView.apply {
tv_reminder.text = curr_item.text;
cb_check.isChecked = curr_item.checked
cb_check.setOnCheckedChangeListener { _, isChecked ->
//changing status of checked
curr_item.checked = isChecked
for (i in items.indices.reversed()) {
if (items[i].checked) {
items.removeAt(i)
notifyItemRemoved(i)
}
}
}
}
}
override fun getItemCount(): Int {
return items.size
}
fun addItem (new_item: Item){
items.add (new_item)
notifyItemInserted(items.size - 1)
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recyclerView"
android:layout_width="match_parent"
android:layout_height="0dp"
android:background="#color/basically_black"
app:layout_constraintBottom_toTopOf="#+id/et_reminder"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<EditText
android:id="#+id/et_reminder"
android:layout_width="0dp"
android:layout_height="45dp"
android:hint="Reminder"
android:textSize="20sp"
android:textColorHint="#color/white_purple"
android:textColor="#color/white_purple"
android:background="#color/basically_black"
android:paddingStart="10dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="#+id/btn_add"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#id/recyclerView"/>
<Button
android:id="#+id/btn_add"
android:layout_width="45dp"
android:layout_height="wrap_content"
android:text="+"
android:textSize="20sp"
android:background="#color/basically_black"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
list_item.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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="55dp"
android:paddingStart="10dp">
<TextView
android:id="#+id/tv_reminder"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:paddingTop="0dp"
android:text="temp"
android:textColor="#color/white_purple"
android:textSize="20sp"
android:maxLines="1"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toStartOf="#+id/cb_check"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<CheckBox
android:id="#+id/cb_check"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
popup_s.xml
<?xml version="1.0" encoding="utf-8"?>
<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="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true">
<EditText
android:id="#+id/et_r"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:hint="Reminder"
android:textColor="#color/white_purple"
android:textColorHint="#color/gray"
android:textSize="20sp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="1.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="1.0">
</EditText>
</androidx.constraintlayout.widget.ConstraintLayout>
I think that happen because you are trying to pass applicationContext it will give you Unable to add window -- token null is not valid; is your activity running?
try to pass the current activity context instead cause PopupWindow can only be attached to an Activity
val view : View = LayoutInflater.from(this).inflate (R.layout.popup_s,null)
val popup = PopupWindow(view, 250, 250,true)
popup.showAtLocation(view, Gravity.NO_GRAVITY, 0,0)

Guidelines Inside ScrollView - use Viewport %

I would like to add content to an app that starts at about 70% down vertically and can be scrolled upwards to cover the top 70% views.
I thought of using two children ConstraintLayout's inside a parent ConstraintLayout - the two children would be on top of each other. One would contain the views that would populate the first 70% of the screen while the other would contain a NestedScrollView which has an invisible <View> that takes up 70% of the height and then the additional content that can be scrolled up.
I'm facing a problem with marking the 70% spot - using a Guideline inside the NestedScrollView isn't working because the %s are fluid (it matches to 70% of the content inside the NestedScrollView instead of 70% of the viewable screen). Using a Guideline outside the NestedScrollView doesn't work because well... constraints have to be siblings to compile.
How can I accomplish this?
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/parentLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/firstConstraintLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/red5F"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent">
// A bunch of content that should fill up the first 70% of the screen and be covered by the overlay if user scrolls
</androidx.constraintlayout.widget.ConstraintLayout>
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/overlayConstraintLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent">
<androidx.core.widget.NestedScrollView
android:layout_width="match_parent"
android:layout_height="0dp"
android:fillViewport="true"
android:id="#+id/scrollView"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/overlayInnerLayout">
<androidx.constraintlayout.widget.Guideline
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/verticalGuidelineOverlay"
android:orientation="horizontal"
app:layout_constraintGuide_percent="0.7"/>
<View
android:layout_width="match_parent"
android:layout_height="0dp"
android:id="#+id/spacerView"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toTopOf="#id/verticalGuidelineOverlay"
app:layout_constraintLeft_toLeftOf="parent"/>
// More content here that the user could scroll upwards that would start at the 70% point and eventually cover the entire screen.
</ConstraintLayout>
</NestedScrollView>
</ConstraintLayout>
</ConstraintLayout>
Video w/example here: https://imgur.com/a/BTolYUu
Try out this method,
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
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/parentLayout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/firstConstraintLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#android:color/transparent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent">
</androidx.constraintlayout.widget.ConstraintLayout>
<androidx.constraintlayout.widget.ConstraintLayout
android:id="#+id/overlayConstraintLayout"
android:layout_width="match_parent"
android:layout_height="match_parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent">
<androidx.core.widget.NestedScrollView
android:id="#+id/scrollView"
android:layout_width="match_parent"
android:layout_height="0dp"
android:fillViewport="true"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:weightSum="1">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="0.7"
android:orientation="horizontal">
<RelativeLayout
android:id="#+id/transparentView"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
<View
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_weight="0.3" />
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#drawable/bg">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:padding="20sp"
android:text="#string/lorem_ipsum"
tools:ignore="MissingConstraints"
android:textSize="18sp"/>
</RelativeLayout>
</LinearLayout>
</androidx.core.widget.NestedScrollView>
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.constraintlayout.widget.ConstraintLayout>
set 70% height programatically using layoutParams
val transparentView = findViewById<RelativeLayout>(R.id.transparentView)
val metrics = DisplayMetrics()
windowManager.defaultDisplay.getMetrics(metrics)
val height = Math.min(metrics.widthPixels, metrics.heightPixels) //height
val params = transparentView.layoutParams
params.height = (height * 70) / 70
transparentView.layoutParams = params
you will get the required result : enter link description here
Remove guidelines and use a view like this as a spacer view. It's height constrained to be 1.15 of it's width. You can change it around a littile to get what you want
<View
android:id="#+id/spacerView"
android:layout_width="0dp"
android:layout_height="0dp"
app:layout_constraintDimensionRatio="1:1.15"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"/>
Also just as an advice
you're not supposed to use match_parent in ConstraintLayout, use 0dp and constraint it to both sides.
Top layout can be replaced with FrameLayout, cause you don't really use any constraints
You can use a customized BottomSheetDialogFragment that has a theme of Theme_Translucent_NoTitleBar, and change the y value of the root layout of the dialog whenever the user drags it up or down.
class MyDialogFragment(height: Int) : BottomSheetDialogFragment(), View.OnTouchListener {
private val outsideWindowHeight = height
private val rootLayout by lazy {
requireView().findViewById<LinearLayout>(R.id.dialog_root)
}
private var oldY = 0
private var baseLayoutPosition = 0
private var defaultViewHeight = 0
private var isClosing = false
private var isScrollingUp = false
private var isScrollingDown = false
override fun onCreateDialog(savedInstanceState: Bundle?): Dialog {
return BottomSheetDialog(
requireContext(),
android.R.style.Theme_Translucent_NoTitleBar
)
}
override fun onCreateView(
inflater: LayoutInflater,
container: ViewGroup?,
savedInstanceState: Bundle?
): View {
val view: View = inflater.inflate(
R.layout.fragment_dialog, container,
false
)
view.setBackgroundResource(R.drawable.rounded_background)
(dialog as BottomSheetDialog).apply {
setCancelable(false)
behavior.peekHeight =
(outsideWindowHeight * 0.3).toInt() // Minimum height of the BottomSheet is 30% of the root layout (to leave the 70% to the main layout)
}
return view
}
#SuppressLint("ClickableViewAccessibility")
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
rootLayout.setOnTouchListener(this)
}
#SuppressLint("ClickableViewAccessibility")
override fun onTouch(v: View?, event: MotionEvent?): Boolean {
// Get finger position on screen
val y = event!!.rawY.toInt()
// Switch on motion event type
when (event.action and MotionEvent.ACTION_MASK) {
MotionEvent.ACTION_DOWN -> {
// save default base layout height
defaultViewHeight = rootLayout.height
oldY = y
baseLayoutPosition = rootLayout.y.toInt()
}
MotionEvent.ACTION_UP -> {
// If user was doing a scroll up
if (isScrollingUp) {
// Reset baselayout position
rootLayout.y = 0f
// We are not in scrolling up anymore
isScrollingUp = false
}
// If user was doing a scroll down
if (isScrollingDown) {
// Reset baselayout position
rootLayout.y = 0f
// Reset base layout size
rootLayout.layoutParams.height = defaultViewHeight
rootLayout.requestLayout()
// We are not in scrolling down anymore
isScrollingDown = false
}
}
MotionEvent.ACTION_MOVE -> {
if (rootLayout.y <= -100) {
return true
}
if (!isClosing) {
val currentYPosition = rootLayout.y.toInt()
// If we scroll up
if (oldY > y) {
// First time android rise an event for "up" move
if (!isScrollingUp) {
isScrollingUp = true
}
rootLayout.y = rootLayout.y + (y - oldY)
} else {
// First time android rise an event for "down" move
if (!isScrollingDown) {
isScrollingDown = true
}
// change position because view anchor is top left corner
rootLayout.y = rootLayout.y + (y - oldY)
rootLayout.requestLayout()
}
// Update position
oldY = y
}
}
}
return true
}
}
fragment_dialog.xml (Nothing fancy):
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/dialog_root"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:id="#+id/tv_bottom_sheet_heading"
android:layout_width="wrap_content"
android:layout_height="#dimen/dp_56"
android:layout_marginStart="#dimen/dp_16"
android:layout_marginEnd="#dimen/dp_16"
android:gravity="center"
android:text="#string/bottom_sheet_option_heading"
android:textColor="#android:color/black"
android:textSize="16sp" />
<TextView
android:id="#+id/tv_btn_add_photo_camera"
android:layout_width="match_parent"
android:layout_height="#dimen/dp_48"
android:layout_marginStart="#dimen/dp_16"
android:layout_marginEnd="#dimen/dp_16"
android:backgroundTint="#android:color/white"
android:drawableStart="#drawable/ic_camera_alt_black_24dp"
android:drawableLeft="#drawable/ic_camera_alt_black_24dp"
android:drawablePadding="#dimen/dp_32"
android:drawableTint="#color/md_bottom_sheet_text_color"
android:gravity="start|center_vertical"
android:text="#string/bottom_sheet_option_camera"
android:textColor="#color/md_bottom_sheet_text_color"
android:textSize="16sp" />
<TextView
android:id="#+id/tv_btn_add_photo_gallery"
android:layout_width="match_parent"
android:layout_height="48dp"
android:layout_marginStart="#dimen/dp_16"
android:layout_marginEnd="#dimen/dp_16"
android:backgroundTint="#android:color/white"
android:drawableStart="#drawable/ic_insert_photo_black_24dp"
android:drawableLeft="#drawable/ic_insert_photo_black_24dp"
android:drawablePadding="#dimen/dp_32"
android:drawableTint="#color/md_bottom_sheet_text_color"
android:gravity="start|center_vertical"
android:text="#string/bottom_sheet_option_gallery"
android:textColor="#color/md_bottom_sheet_text_color"
android:textSize="16sp" />
<View
android:layout_width="match_parent"
android:layout_height="1dp"
android:layout_marginTop="#dimen/md_bottom_sheet_separator_top_margin"
android:layout_marginBottom="#dimen/dp_8"
android:background="#color/grayTextColor" />
<TextView
android:id="#+id/tv_btn_remove_photo"
android:layout_width="match_parent"
android:layout_height="#dimen/dp_48"
android:layout_marginStart="#dimen/dp_16"
android:layout_marginEnd="#dimen/dp_16"
android:backgroundTint="#android:color/white"
android:drawableStart="#drawable/ic_delete_black_24dp"
android:drawableLeft="#drawable/ic_delete_black_24dp"
android:drawablePadding="#dimen/dp_32"
android:drawableTint="#color/md_bottom_sheet_text_color"
android:gravity="start|center_vertical"
android:text="#string/bottom_sheet_option_remove_photo"
android:textColor="#color/md_bottom_sheet_text_color"
android:textSize="16sp" />
<com.google.android.material.button.MaterialButton
android:id="#+id/btn_material"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Material button"
android:textAppearance="#style/TextAppearance.AppCompat.Medium" />
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/longText1"
android:textColor="#color/white"
android:textSize="22sp" />
</LinearLayout>
And send the height of the root ViewGroup of the main layout to the dialog in the main activity:
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val root = findViewById<ConstraintLayout>(R.id.root)
root.viewTreeObserver.addOnGlobalLayoutListener(object :
OnGlobalLayoutListener {
override fun onGlobalLayout() {
root.viewTreeObserver
.removeOnGlobalLayoutListener(this)
val dialogFragment = MyDialogFragment(root.height)
dialogFragment.show(supportFragmentManager, "dialog_tag")
}
})
}
}
Preview:

Add buttons programmatically to Flow of ConstraintLayout?

I have seen the code for adding buttons to a ConstraintLayout in an existing question, but how do I do that with a Flow? That is, I do not want to define the top/left of the button relative to the ConstraintView itself, but I want the buttons to be next to the previous one and wrap at the end of the line.
I have tried the following but no button was showing.
override fun onCreate(savedInstanceState: Bundle?)
{
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val flow = findViewById<Flow>(R.id.flow);
val lay = flow.parent as ConstraintLayout;
val cs = ConstraintSet();
cs.clone(lay);
for (i in 1 .. 10)
{
val btn = Button(this)
btn.text = "Test ${i}";
btn.id = 49393+i;
flow.addView(btn)
cs.constrainWidth(btn.id, 400);
cs.constrainHeight(btn.id, 100);
cs.applyTo(lay);
}
}
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto">
<ScrollView
android:id="#+id/sv"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/textview1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="#string/large_text"
android:textAppearance="#style/TextAppearance.AppCompat.Large"
android:textIsSelectable="true" />
</ScrollView>
<androidx.constraintlayout.helper.widget.Flow
android:id="#+id/flow"
android:layout_width="match_parent"
android:layout_height="100dp"
android:background="#FF0000"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
/>
</androidx.constraintlayout.widget.ConstraintLayout>
You haven't ever added the button to the layout. The Flow.addView method only adds it to the helper if it's already a child of the relevant ConstraintLayout.
From the documentation:
The referenced view need to be a child of the helper's parent.

Prevent RecyclerView from swallowing touch events without creating custom ViewGroup

I'm currently working on a UI that looks like this
The blue part is a ConstraintLayout while the purple part is a RecyclerView inside it (it's a RecyclerView because it's content are dynamic based on service response).
I'm setting onClick handler on the ConstraintLayout that would take the user to another page. The problem is the RecyclerView is consuming the clicks and not forwarding it to its parent. Thus onClick handler works for the blue area, but not for the purple area.
I tried setting android:clickable="false" and android:focusable="false" in the RecyclerView but it still won't propagate the clicks to its parent.
One solution I came across is to extend from ConstraintLayout and override onInterceptTouchEvent() to return true. However I have a strict requirement in my project to not create custom widgets, so I cannot use this solution.
Is there a way to tell RecyclerView to stop consuming touch events?
Activity layout:
<FrameLayout 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">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="300dp"
android:layout_margin="16dp"
android:background="#42d7f4"
android:onClick="navigate"
android:padding="16dp">
<TextView
android:id="#+id/headerText"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="FRUITS"
android:textSize="36sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/itemsList"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:background="#9f41f2"
android:clickable="false"
android:focusable="false"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
</FrameLayout>
Item layout:
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/itemText"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="8dp"
android:clickable="false"
android:focusable="false" />
Activity.kt:
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val rcView = findViewById<RecyclerView>(R.id.itemsList)
rcView.layoutManager = LinearLayoutManager(this)
val items = listOf("Apple", "Banana", "Oranges", "Avocado")
rcView.adapter = ItemAdapter(items)
}
fun navigate(view: View) {
Toast.makeText(this, "Navigating to details page", Toast.LENGTH_SHORT)
.show()
}
}
class ItemAdapter(private val data: List<String>) : RecyclerView.Adapter<ItemViewHolder>() {
override fun getItemCount(): Int = data.size
override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ItemViewHolder {
val view = LayoutInflater.from(parent.context).inflate(R.layout.item, parent, false)
return ItemViewHolder(view)
}
override fun onBindViewHolder(holder: ItemViewHolder, position: Int) {
holder.bind(data[position])
}
}
class ItemViewHolder(view: View) : RecyclerView.ViewHolder(view) {
private val itemTv: TextView = view.findViewById(R.id.itemText)
fun bind(item: String) {
itemTv.text = item
}
}
If you freeze the layout after you've set the adapter it no longer swallows clicks:
recyclerView.isLayoutFrozen = true // kotlin
recyclerView.setLayoutFrozen(true); // java
Just keep in mind if you need to change the data in the adapter you have to unfreeze the layout before you call notifyDataSetChanged and then re-freeze the layout. I don't love this solution but it's the only one that worked for me.
One way to approach this is to set the RecyclerView row with a click listener and to disable clicks and long clicks on the children of the RecyclerView row as follows:
ConstraintLayout: `android:onClick="navigate"`
For the item layout: `android:onClick="navigate"`
TextView: android:clickable="false"
android:longClickable="false"
(etc. for all children of the row)
I think what is missing is to make the TextView not long clickable.
You can set your RecyclerView focus to false.
recyclerView.setFocusable(false);
And/Or set its rows view.setFocusable(false);
EDIT
If you want to give the ConstraintLayout the focus
layout.setFocusable(true);
layout.setClickable(true);
//
// add click listener and event ....
//
For more information please refer to the official documentation provided by Google
Hope this helps, cheers
Probably the easiest way to completely block interaction with anything inside a single view is to put a transparent view over it that intercepts all touch events. You can set click on that view manage all the functionality through that view.
For example like this
<FrameLayout 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">
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="300dp"
android:layout_margin="16dp"
android:background="#42d7f4"
android:padding="16dp">
<TextView
android:id="#+id/headerText"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:text="FRUITS"
android:textSize="36sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/itemsList"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:background="#9f41f2"
android:clickable="false"
android:focusable="false"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent" />
<View
android:id="#+id/clickView"
android:layout_width="0dp"
android:layout_height="0dp"
android:onClick="navigate"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintBottom_toBottomOf="parent"
android:clickable="true"/>
</androidx.constraintlayout.widget.ConstraintLayout>
</FrameLayout>
Now you can functionality perform through that view instead through ConstraintLayout.
Moreover, you look at this answer

Changing width and height in ConstraintLayout programmatically doesn't work

I would like to change the following UI to be full screen programmatically.
<android.support.constraint.ConstraintLayout
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/layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity"
>
<TextView
android:id="#+id/one"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="ONE"
android:background="#android:color/darker_gray"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintRight_toLeftOf="#+id/two"
/>
<TextView
android:id="#+id/two"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TWO"
android:background="#android:color/holo_blue_dark"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintLeft_toRightOf="#+id/one"
/>
</android.support.constraint.ConstraintLayout>
In my Kotlin file:
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val param = ConstraintLayout.LayoutParams(0, 0)
one.layoutParams = param
two.layoutParams = param
}
}
Both TextView disappears after I set the width and height to 0 instead of being scratched fullscreen.
Desired UI
You're doing it wrong. You've to apply a new ConstraintSet like:
val constraintSet1 = ConstraintSet()
constraintSet1.clone(yourConstraintLayout)
val constraintSet2 = ConstraintSet()
constraintSet2.clone(yourConstraintLayout)
constraintSet2.constrainWidth(R.id.one, 0)
constraintSet2.constrainWidth(R.id.two, 0)
constraintSet2.constrainHeight(R.id.one, 0)
constraintSet2.constrainHeight(R.id.two, 0)
// to switch to full screen
constraintSet2.applyTo(yourConstraintLayout)
// to get back to your original screen
constraintSet1.applyTo(yourConstraintLayout)

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