GONE View behaves like INVISIBLE (android) - android

I have set in XML visibility="gone" for the View. On the first click on the button (), the View should become visible (it works) viewView.visibility = VISIBLE. The second time you click on the button, the view should become "gone" again viewView.visibility = GONE.
But instead, the View doesn't disappear, but just becomes transparent, as if I had set invisible (look at the illustration from Layout Inspector).
How can I make the View truly "gone" like in the first frame?
Please look the illustration from Layout Inspector
Example code
var isVisible = false
val button = findViewById<View>(id.button)
val view = findViewById<View>(id.view)
button.setOnClickListener {
view.visibility = if (isVisible) { GONE } else { VISIBLE }
isVisible = !isVisible
}
And XML
<Button
android:id="#+id/button"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="0.2"
android:background="#color/design_default_color_primary" />
<View
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="0.4" />
<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="0.2">
<View
android:id="#+id/view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/design_default_color_secondary"
android:visibility="gone" />
</androidx.constraintlayout.widget.ConstraintLayout>

I think you're worrying too much about what's happening behind the scenes. Here's what happens if you add a TextView below that View:
Yes view still has its full size, but it's not actually affecting the layout. That's what GONE means - it's not visible, but it's also behaving as though it's not there, and everything else is laid out accordingly.
That doesn't mean the view itself has been recalculated with zero height or anything - for one thing, removing something doesn't change its height, right? It's just not in the layout anymore, so the space it's taking up is now zero. And there's also no reason to recalculate the height while the View isn't being displayed, it would be wasted work. It's just there, hanging around, waiting to be added to the layout again.
It's not like you can click it while it's in this state anyway, so what it's actually doing and how the system is managing stuff shouldn't be relevant. If your code does somehow rely on the View being "gone" in some sense (not present in the layout, garbage collected, zero width and height) then you'll have to account for determining that yourself, and whatever you're doing now isn't enough. You could check its visibility property remember!
Also just as an aside, be careful about what you name things - an ID called view and especially a variable called view inside a class that already has a view property is just asking for trouble. Same with a variable called isVisible being referenced in the scope of a Button and a Fragment, both of which have a property with the same name (and you'll get a warning about this one, accidental override)
It just leads to bugs when you accidentally reference the wrong thing. If these are just placeholder names you're using for your question, bear in mind people will copy your code to try and help you, and you're making work for them when they have to fix it. Not having a go or anything, just something to keep in mind!

try this:
button.setOnClickListener { v ->
v?.let {
val isViewVisible: Boolean = view.isVisible
view.isVisible = !isViewVisible
}
}

Related

Loading items into a RecyclerView with stackFromEnd = true doesn't scroll to bottom

I have a chat app and i'm trying to ensure that when the user opens the screen the items display from the bottom with the most recent right above the input area. I've used a custom view for the input area and both the recycler and the custom view are within a ConstraintLayout.
My problem is that when I load items into the list, if the number of items is greater than the size of the recycler, it will not fully show the last item. When I make the input area visibility = Gone then the items display properly at the bottom. It's almost like the recyclers LinearLayoutManager thinks that the height of the Recycler is of the screen without the input field. I've manually printed out the size of the views and used layout inspector to ensure that the recycler is indeed drawn in the correct location (above the input and below the navigation bar).
What could be causing such an issue? I should note that whenever you click on a Linkified text in a chat bubble that the list scrolls a small amount equal to the offset that's incorrect when you open the screen. Clearly something is not measuring right here and not sure where to begin.
I should also note that if I try to add a post with smoothScroll it will go to the end of the list but then whenever a new item appears in the list from sending a message the items above the most recently added one seem to jump up a little with an unnecessary animation. It's like the last item in the list is in some special state?
if you're curious this is my scrolling function:
private fun scrollToFirstItem(dueToKeyboard: Boolean = false) {
val stackingFromEnd = (recyclerView.layoutManager as LinearLayoutManager).stackFromEnd
if (stackingFromEnd) {
val firstPosition = recyclerView.adapter?.itemCount?: 0 - 1
if (dueToKeyboard ) {
recyclerView.scrollBy(0, Integer.MAX_VALUE)
} else {
recyclerView.scrollToPosition(firstPosition)
}
recyclerView.post { recyclerView.smoothScrollToPosition(firstPosition) }
} else {
recyclerView.scrollToPosition(0)
}
}
And my xml for my fragment:
<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">
<include
android:id="#+id/searchView"
layout="#layout/compose_new_message_include"/>
<com.airbnb.epoxy.EpoxyRecyclerView
android:id="#+id/conversationEpoxyRV"
android:layout_width="match_parent"
android:layout_height="0dp"
android:scrollbars="vertical"
app:layout_constraintTop_toBottomOf="#id/searchView"
app:layout_constraintBottom_toTopOf="#id/composeView"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintLeft_toLeftOf="parent"
tools:listitem="#layout/conversation_item_inbound"/>
<include layout="#layout/conversation_pip_view"
android:id="#+id/selectedMediaContainer"/>
<****.ComposeView
android:id="#+id/composeView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintBottom_toBottomOf="parent"/>
</androidx.constraintlayout.widget.ConstraintLayout>
Any help is appreciated, I'm so lost..
To me this feels like more of an issue in the layout rather than in the scrolling function. I hope that this can be resolved easily if you use a Relative Layout instead of a Linear Layout. So in case if it may be helpful, i'll add my solution below using a Relative Layout.
<RelativeLayout
android:id="#+id/layout"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recycle_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_above="#id/input_field">
</androidx.recyclerview.widget.RecyclerView>
<EditText
android:id="#+id/input_field"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_alignParentBottom="true"/>
</RelativeLayout>
So in case if it is not clear what i have done, an EditText element is set to align to the bottom of parent which is a Relative Layout. Then a RecyclerView is added so that RecylerView will be always constraint above the EditText but not overlapped.
Everything looks fine, except the restrictions you added to recycleview design, I see that you are setting the recycleview to top of searchView app:layout_constraintTop_toBottomOf="#id/searchView" while the searchView view is not restricted as should it be.
It's better when using ConstraintLayout to restrict every view inorder avoid unexpected behaviors, because every view has a relation with other view will be effected with other view (x, y), therefore your searchView should be look like:
<include
android:id="#+id/searchView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
layout="#layout/compose_new_message_include"/>
Give the size of arraylist of your data to smoothScrollToPosition
var linearLayoutManager = LinearLayoutManager(context)
recyclerView.layoutManager=linearLayoutManager
recyclerView.adapter=adapter
linearLayoutManager.setStackFromEnd(true)
adapter.notifyDataSetChanged()
recyclerView.smoothScrollToPosition(dataMsgs.size())
I had a similar problem some years back and I solved it with scrollToPositionWithOffset (support library). Of course this was before constraint was used....
I kept my newer items at the bottom, too. The code I used for scrolling after inserting an item was:
((LinearLayoutManager) layoutManager).scrollToPositionWithOffset(getItemCount() - 1, 0);
To scroll and adjust the awkward positioning after removing an item, I used:
View vTopCard = layoutManager.getChildAt(0);
// Get its adapter position
final int topCardPos = layoutManager.getPosition(vTopCard);
// Get top of card position
int topOffset = layoutManager.getDecoratedTop(vTopCard);
int cardMargin = (int) getResources().getDimension(R.dimen.card_vertical_margin);
((LinearLayoutManager) layoutManager).scrollToPositionWithOffset(topCardPos, topOffset - cardMargin);
The getDecoratedTop helps with the "bounce" and final positioning, as does factoring the vertical margin.
I hope this helps (at least part of your issue)! Like I said, this is old code (when I was learning to program Android and Java at the same time), so if I left something out, let me know and I'll reexamine the app's code in more detail (though, I'll have to find the time).
Good luck!

Custom view hast strange layout behavior

Basically I have a custom View-Class (MessageViewAudio) which extends ConstraintLayout. This custom view contains another ConstraintLayout which contains another custom view (AudioVisualizationView) I made myself. The problem ist that the Top-Layer-Custom View (MessageViewAudio) always has some space to the right. I attached the information the layout inspector gave me. If you need any more code, just let me know.
As already said, I inspected the layout and tried different types of containers and manually tried to remove margins and paddings from every view mentioned above. But the layout inspector already says that there is no margin oder padding that could cause that strange behavior. There are two ways I got this to work One: is to remove all containers and just add the AudioVisualizationView custom view. Two: is to remove the property constrainedWidth = true from the LayoutParams of MessageViewAudio. Now I need constrainedWidth = true but I have that feeling that this property is kind of the problem, I can't just figure out why constrainedWidth results in this behavior.
With containers
Not Working
Hierarchy
ChatMessage
MessageViewAudio
audioContent
visualizationView
Without containers
Working
The only code I can provide for now is the xml of the views:
audioContent + visualizationView:
<com.jooyapp.jooy.custom_views.RoundedConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/audioContent"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
app:backgroundColor="#color/colorAccent"
app:radius="20">
<!--android:paddingStart="10dp"-->
<!--android:paddingTop="10dp"-->
<!--android:paddingEnd="10dp"-->
<!--android:paddingBottom="10dp"-->
<com.jooyapp.jooy.custom_views.AudioVisualizationView
android:id="#+id/visualizationView"
android:layout_width="wrap_content"
android:background="#color/light_grey"
android:layout_height="wrap_content" />
</com.jooyapp.jooy.custom_views.RoundedConstraintLayout>
All others are created programmatically
All in all my problem is that I don't understand where this space to the right of the custom view comes.

How to avoid total view-hierarchy re-layout when using EditText?

Background
I have a rather complex layout being shown to the user in an activity.
One of the views is an EditText.
Since I had to make one of the views stay behind the soft-keyboard, yet the rest above it, I had to listen to view-layout changes (written about it here).
The problem
I've noticed that whenever the EditText has focus and shows its caret, the entire view-hierarchy gets re-layout.
You can see it by either looking at the log of the listener I've created, or by enabling "show surface updates" via the developers settings.
This causes bad performance on some devices, especially if the layout of the activity is complex or have fragments that have complex layouts.
The code
I'm not going to show the original code, but there is a simple way to reproduce the issue:
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.example.user.myapplication.MainActivity">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="just some text"/>
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="phone"
android:text="write here"
android:textSize="18dp"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="just some text 2"/>
</LinearLayout>
</FrameLayout>
MainActivity.java
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
findViewById(android.R.id.content).getViewTreeObserver().addOnPreDrawListener(new OnPreDrawListener() {
#Override
public boolean onPreDraw() {
Log.d("AppLog", "onPreDraw");
return true;
}
});
}
}
What I've tried
When disabling the caret (using "cursorVisible", which for some reason is called a "cursor" instead) , I can see that the problem doesn't exist.
I've tried to find an alternative to the built-in caret behavior, but I can't find. Only thing I've found is this post, but it seems to make it static and I'm not sure as to how well it performs (performance and compatibility vs normal caret).
I've tried to set the size of the EditText forcefully, so that it won't need to cause invalidation of the layout that contains it. It didn't work.
I've also noticed that on the original app, the logs can (for some reason) continue being written even when the app goes to the background.
I've reported about this issue (including sample and video) here, hoping that Google will show what's wrong or a fix for this.
The question
Is there a way to avoid the re-layout of the entire view hierarchy ? A way that will still let the EditText have the same look&feel of normal EditText?
Maybe a way to customize how the EditText behaves with the caret?
I've noticed that whenever the EditText has focus and shows its caret,
the entire view-hierarchy gets re-layout.
This is not true. Size and position of EditText is constant - there is no re-layouting. You can check it by using code below.
findViewById(android.R.id.content).getViewTreeObserver().addOnGlobalLayoutListener(new ViewTreeObserver.OnGlobalLayoutListener() {
#Override
public void onGlobalLayout() {
Log.d("AppLog", "Layout phase");
}
});
Because of blinking caret - EditText constatly calls invalidate(). This forces the GPU to draw EditText again.
On my nexus 5 (marshmallow) I see that only EditText beeing redrawn (Show GPU view updates - enabled).
How about overriding dispatchOnPreDraw() all the vies you use in activity and having flag to check whether that specific view needs to redraw ?
As you need to disable redraw of all other views only when a text view is on focus. So when a text view is on focus have a flag to disable the redrawing of other views.
if dispatchOnPreDraw() method returns false then refreshing of view will be continues else not. I don't know how complex is your layout and how many views are used, but here a separate class should extent a view used and override that method, and also need a mechanism/variable to distinguish the object in current focus.
Hope this method helps!

Android, How to remove a view from UI?

In my main page of my application, server sends me some flags. One of then is advertise flag. if it is set to true i need to show advertise and if it is set to false i shouldn't show it.
now, the problem. I need to put the space of advertise in XML file like this.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical">
<RileativeLayout
android:id="#+id/adv"
android:layout_width="fill_parent"
android:layout_height="100dip">
</RileativeLayout>
.
.
.
</LinearLayout >
according to above code if the flag is set to false, i don't show advertise but the gap is still remain in my screen. How to remove it from my code dynamically and shift other views (which are blow of it) up?
as mentioned above in the comments for your question: a view has a few different View options.
View.VISIBLE: this means that it's visible and can be seen by the user.
View.INVISIBLE: this means the view is still in the layout but cannot be seen by the user (the user can't interact with it either).
View.GONE: this means the view is destroyed and is no longer part of it.
to remove a View completely from the layout you should use View.GONE, if you're going to make it visible you should use View,INVISIBLE.
try this when your flag is false
add.setVisibility(View.GONE);
You can "remove" the View by changing the visibility of it. Use
View ad = findViewById(R.id.adv);
ad.setVisibility(View.GONE);

How to bring view in front of everything?

I have activity and a lot of widgets on it, some of them have animations and because of the animations some of the widgets are moving (translating) one over another. For example the text view is moving over some buttons . . .
Now the thing is I want the buttons to be always on the front. And when the textview is moving I want to move behind the buttons.
I can not achieve this I tried everything I know, and "bringToFront()" definitelly doesn't work.
note I do not want to control the z-order by the order of placing element to layout cause I simply can't :), the layout is complex and I can not place all the buttons at the begging of the layout
You can call bringToFront() on the view you want to get in the front
This is an example:
yourView.bringToFront();
With this code in xml
android:translationZ="90dp"
I've been looking through stack overflow to find a good answer and when i couldn't find one i went looking through the docs.
no one seems to have stumbled on this simple answer yet:
ViewCompat.setTranslationZ(view, translationZ);
default translation z is 0.0
An even simpler solution is to edit the XML of the activity. Use
android:translationZ=""
bringToFront() is the right way, but, NOTE that you must call bringToFront() and invalidate() method on highest-level view (under your root view), for e.g.:
Your view's hierarchy is:
-RelativeLayout
|--LinearLayout1
|------Button1
|------Button2
|------Button3
|--ImageView
|--LinearLayout2
|------Button4
|------Button5
|------Button6
So, when you animate back your buttons (1->6), your buttons will under (below) the ImageView. To bring it over (above) the ImageView you must call bringToFront() and invalidate() method on your LinearLayouts. Then it will work :)
**NOTE: Remember to set android:clipChildren="false" for your root layout or animate-view's gradparent_layout. Let's take a look at my real code:
.xml
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:hw="http://schemas.android.com/apk/res-auto"
android:id="#+id/layout_parent"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/common_theme_color"
android:orientation="vertical" >
<com.binh.helloworld.customviews.HWActionBar
android:id="#+id/action_bar"
android:layout_width="match_parent"
android:layout_height="#dimen/dimen_actionbar_height"
android:layout_alignParentTop="true"
hw:titleText="#string/app_name" >
</com.binh.helloworld.customviews.HWActionBar>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_below="#id/action_bar"
android:clipChildren="false" >
<LinearLayout
android:id="#+id/layout_top"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:gravity="center_horizontal"
android:orientation="horizontal" >
</LinearLayout>
<ImageView
android:id="#+id/imgv_main"
android:layout_width="#dimen/common_imgv_height"
android:layout_height="#dimen/common_imgv_height"
android:layout_centerInParent="true"
android:contentDescription="#string/app_name"
android:src="#drawable/ic_launcher" />
<LinearLayout
android:id="#+id/layout_bottom"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:gravity="center_horizontal"
android:orientation="horizontal" >
</LinearLayout>
</RelativeLayout>
</RelativeLayout>
Some code in .java
private LinearLayout layoutTop, layoutBottom;
...
layoutTop = (LinearLayout) rootView.findViewById(R.id.layout_top);
layoutBottom = (LinearLayout) rootView.findViewById(R.id.layout_bottom);
...
//when animate back
//dragedView is my layoutTop's child view (i added programmatically) (like buttons in above example)
dragedView.setVisibility(View.GONE);
layoutTop.bringToFront();
layoutTop.invalidate();
dragedView.startAnimation(animation); // TranslateAnimation
dragedView.setVisibility(View.VISIBLE);
GLuck!
Try FrameLayout, it gives you the possibility to put views one above another. You can create two LinearLayouts: one with the background views, and one with foreground views, and combine them using the FrameLayout. Hope this helps.
If you are using ConstraintLayout, just put the element after the other elements to make it on front than the others
i have faced the same problem.
the following solution have worked for me.
FrameLayout glFrame=(FrameLayout) findViewById(R.id.animatedView);
glFrame.addView(yourView);
glFrame.bringToFront();
glFrame.invalidate();
2nd solution is by using xml adding this attribute to the view xml
android:translationZ=""
You can try to use the bringChildToFront, you can check if this documentation is helpful in the Android Developers page.
There can be another way which saves the day. Just init a new Dialog with desired layout and just show it. I need it for showing a loadingView over a DialogFragment and this was the only way I succeed.
Dialog topDialog = new Dialog(this, android.R.style.Theme_Translucent_NoTitleBar);
topDialog.setContentView(R.layout.dialog_top);
topDialog.show();
bringToFront() might not work in some cases like mine. But content of dialog_top layout must override anything on the ui layer. But anyway, this is an ugly workaround.
You can use BindingAdapter like this:
#BindingAdapter("bringToFront")
public static void bringToFront(View view, Boolean flag) {
if (flag) {
view.bringToFront();
}
}
<ImageView
...
app:bringToFront="#{true}"/>
The order of the overlapping views really depends of 4 things:
The attribute android:elevation which is measured in dp/sp
The attribute android:translationZ which is also measured in dp/sp.
In Constraint Layout, the order in which you put the views in your Component Tree is also the order to be shown.
The programmatically order that you set through methods like view.bringToFront() in your kotlin/java code.
The numerals 1 and 2 compite with each other and take preference over the points 3 and 4: if you set elevation="4dp" for View 1 and translationZ="2dp" for View 2, View 1 will always be on top regardless of the numerals 3 and 4.
Thanks to Stack user over this explanation, I've got this working even on Android 4.1.1
((View)myView.getParent()).requestLayout();
myView.bringToFront();
On my dynamic use, for example, I did
public void onMyClick(View v)
{
((View)v.getParent()).requestLayout();
v.bringToFront();
}
And Bamm !
You can use elevation attribute if your minimum api level is 21. And you can reorder view to the bottom of other views to bring it to front. But if elevation of other views is higher, they will be on top of your view.
If you are using a LinearLayout you should call myView.bringToFront() and after you should call parentView.requestLayout() and parentView.invalidate() to force the parent to redraw with the new child order.
Arrange them in the order you wants to show. Suppose, you wanna show view 1 on top of view 2. Then write view 2 code then write view 1 code. If you cant does this ordering, then call bringToFront() to the root view of the layout you wants to bring in front.
Try to use app:srcCompat instead of android:src
You need to use framelayout. And the better way to do this is to make the view invisible when thay are not require. Also you need to set the position for each and every view,So that they will move according to there corresponding position
You can set visibility to false of other views.
view1.setVisibility(View.GONE);
view2.setVisibility(View.GONE);
...
or
view1.setVisibility(View.INVISIBLE);
view2.setVisibility(View.INVISIBLE);
...
and set
viewN.setVisibility(View.VISIBLE);

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