In my application i am adding the view dynamically to the linear layout. each view consists of one button if you click on that then view will be deleted. How to refresh the linear layout? because when i removed any view then the view's positions will be changed.
LinearLayout ll = findViewById(R.id.yourLinearLayout);
To remove any view you can use
ll.removeView(view)// to remove particular view
ll.removeViewAt(position);// to remove view from particular position
Use following logic to remove any view from layout
ll.post(new Runnable() {
public void run() {
ll.removeView(view);
}
});
You question is not that clear. But you could try setting the view as visibility = gone.
layout.removeAllViewsInLayout();
layout.invalidate();
I hope this help
How to refresh the linear layout?
linearLayoutObject.invalidate()
How to remove item from the linear layout?
linearLayoutObject.removeView(View view);
or
linearLayoutObject.removeViewAt(int index);
I hope it helps..
By removing or adding views the linearlayout has to measure and layout all its children again which is why they move. You could simply try setting the visibility to invisible.
myLinearLayout.setVisibility(View.INVISIBLE);
any view set to invisible still retains its size and positioning in the layout but can no longer be seen.
Did you tried
setContentView(R.layout.main);
after remove?
use listview with Adapter to fill the data dynamically (because that's what for they are made) and whenever your data or UI gets changed create new adapter (data set) and notify the adapter about change.
Simply Use linearLayout.removeView(View view);
It would refresh automaically.
Related
I am actually developing an android application which needs to inflates many times the same XML layout.
This layout contains 2 buttons, some textViews and a progressBar which I'll need to update later. I would like to add onClick listeners to the buttons and to set custom tags with setTag() to all of these elements, so I will be able to know which button has been clicked and to modify the right textView (or progressBar).
I inflate the XML with this code :
LinearLayout countersList = (LinearLayout)findViewById(R.id.countersLayout);
View child = getLayoutInflater().inflate(R.layout.counter, null);
countersList.addView(child);
How can I access to the right view to set the tag and to add listeners? Is there a better way to do what I want to do ?
Thank you very much !
As far as how to tag or add onClick listeners to your views: You can add an ID to the views you want to tag and find them using findViewById. For example,
LinearLayout countersList = (LinearLayout)findViewById(R.id.countersLayout);
ViewGroup child = (ViewGroup) getLayoutInflater().inflate(R.layout.counter, null);
child.findViewById(R.id.myButton).setTag("myTagForTheButton");
countersList.addView(child);
On the second question, I'm not sure what your UI looks like, but many repeated views might call for using a ListView.
There is no problem of setting tags and listener
LinearLayout countersList = (LinearLayout)findViewById(R.id.countersLayout);
View child = getLayoutInflater().inflate(R.layout.counter, null);
child.setTag("YourString");
// Similarly
view.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View v)
{
}
});
countersList.addView(child);
If you want it for some of its child you can also do it using findViewById
you can user view.setTag(key, tag) to many tags.
ex:
view.setTag("right_view", rightView);
I'm having some problems when trying to remove the header from a listView. At first I use addHeaderView() to add it, but when I change to another layout I want it to disappear but removeHeaderView() doesn't work...
I also tried setting visibility to GONE and it doesn't disappear...
What can I do?
Thanks in advance
Try the approach mentioned below..
Android ListView#addHeaderView and ListView#addFooterView methods are strange: you have to add the header and footer Views before you set the ListView's adapter so the ListView can take the headers and footers into consideration -- you get an exception otherwise. Here we add a ProgressBar (spinner) as the headerView:
// spinner is a ProgressBar
listView.addHeaderView(spinner);
We'd like to be able to show and hide that spinner at will, but removing it outright is dangerous because we'd never be able to add it again without destroying the ListView -- remember, we can't addHeaderView after we've it's adapter:
listView.removeHeaderView(spinner); //dangerous!
So let's hide it! Turns out that's hard, too. Just hiding the spinner view itself results in an empty, but still visible, header area.
Now try to hide the spinner:
spinner.setVisibility(View.GONE);
Result: header area still visible with an ugly space:
The solution is to put the progress bar in a LinearLayout that wraps it's content, and hiding the content. That way the wrapping LinearLayout will collapse when its content is hidden, resulting in a headerView that is technically still present, but 0dip high:
<LinearLayout
xmlns:a="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="wrap_content">
<!-- simplified -->
<ProgressBar
android:id="#+id/spinner"
android:layout_width="wrap_content"
android:layout_height="wrap_content"/>
</LinearLayout>
Then, set the layout as the header:
spinnerLayout = getLayoutInflater().inflate(R.layout.header_view_spinner, null);
listView.addHeaderView(spinnerLayout);
And when we need to hide it, hide the layout's content, not the layout:
spinnerLayout.findViewById(R.id.spinner).setVisibility(View.GONE);
Now the header disappears from view. No more ugly space at the top!
Most people don't like to use AddHeaderView, however I sometimes found it very convenient, to avoid modifying complex adapters, or if the headers are not very related to them.
With this easy trick you will be able to seamlessly remove/add headers:
I add an empty LinearLayout with orientation vertical, and height wrap_content, as the only Header View (let mListView be the target listView):
LinearLayout mCustomHeaders=new LinearLayout(context);
mCustomHeaders.setOrientation(LinearLayout.VERTICAL);
mListView.addHeaderView(mCustomHeaders);
mListView.setAdapter (.......)
Thenafter, I can add random stuff, anywhere, to the list as header, even when the list is full:
mCustomHeaders.add(myHeaderView1);
mCustomHeaders.add(myHeaderView2);
mCustomHeaders.add(myHeaderView3);
You can also delete all headers, anytime:
mCustomHeaders.removeAllViews(); // will erase all headers
You get the idea .... Hope it helps !
The problem is that you are always creating a new object when you do:
View headerView = someView
So the new view is not the same as the view already added as listView header, try this:
View headerView = inflater.inflate(R.layout.adapter_datatable_saleitem_header, null, false);
headerView.setTag(this.getClass().getSimpleName() + "header");
if (listView.getHeaderViewsCount() > 0) {
View oldView = listView.findViewWithTag(this.getClass().getSimpleName() + "header");
if (oldView != null) {
listView.removeHeaderView(oldView);
}
}
You can check if header count > 0 then remove the header and add it again.
its works fine for me.
View _headerView;
private void function HandleHeaderView(){
if(listView.getHeaderViewsCount() > 0)
{
listView.removeHeaderView(_headerView);
}
/* Add list view header */
_headerView = GetHeaderView();
listView.addHeaderView(_headerView);
}
private View GetHeaderView()
{
View header = getLayoutInflater().inflate(R.layout.header_layout, null);
// TODO: ...
return header
}
Where drawerLogoView is my headerview, here's what I do:
drawerLogoView = mInflater.inflate(R.layout.navigation_drawer_custom_layout, null);
mDrawerList.addHeaderView(drawerLogoView,null,false);
LinearLayout layOut = ((LinearLayout)drawerLogoView.findViewById(R.id.NavProfilePreviewLayout));
layOut.setLayoutParams(new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, 0));
That way, it becomes invisible :D
To show it back, you can use this:
LinearLayout layOut = ((LinearLayout)drawerLogoView.findViewById(R.id.NavProfilePreviewLayout));
layOut.setLayoutParams(newRelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MATCH_PARENT, RelativeLayout.LayoutParams.WRAP_CONTENT));
If you are using addHeaderView(), you can't delete your header after that.
So, don't use addHeaderView(). Rather, create your own adapter that
blends your main roster of Views with your header. While my
MergeAdapter will not handle your specific case, you can use it to see
the concept of blending multiple row sources:
https://github.com/commonsguy/cwac-merge
I encountered this problem in a slightly disguised scenario: the ListView I was dealing with came from PreferenceFragment, and the header represents a PreferenceCategory. So, my freedom of setting up the ListView was severely limited. But there were two approaches (partly inspired by other answers on this page). One was to add a custom layout to my PreferenceCategory (using a class that extends android.preference.PreferenceCategory, see Custom PreferenceCategory Headings). But I found an easier workaround: for the first Preference in this PreferenceCategory, I override onCreateView():
#Override public View onCreateView(ViewGroup parent) {
parent.setTop(-parent.getChildAt(0).getTop());
return super.onCreateView(parent);
}
I'm developing an android app with fragments. While most of my layouts are pre-determined in the XML, I would like to programmatically insert a new view between views that were already loaded in a LinearLayout at startup.
How do I go about with this?
Thanks
Its possible to specify index while u dynamically add a view to a LinearLayout.
Set height of the first view as
android:layout_height="0dp"
android:layout_weight="1"
Set height = wrap_content for the second view in XML
Then while u are adding new View dynamically, set its height = wrap_content and add it to the parent LinearLayout like this
parentLinearLayout.addView(childView, index);
//index = position where you want to insert the new view.
It might help you. :)
the red View should have the default setting View.setVisibility(View.GONE) right at the beginning. When its time to show up you can switch over to View.setVisibility(View.VISIBLE). I cant verify the solution right now, but it should do the trick. So in this case you are not inserting a new View but make an existing one visible.
I have a ListView. The data behind it is fetched from the Internet, in sets of 10-30 items whenever the user scrolls all the way to the bottom. In order to indicate that it is loading more items, I used addFooterView() to add a simple view that displays a "Loading..." message and a spinner. Now, when I'm out of data (no more data to fetch), I want to hide that message. I tried to do:
loadingView.setVisibility(View.GONE);
Unfortunately, while that does hide the view, it leaves space for it. I.e. I end up with a big blank space where the "Loading" message used to be. How can I go about properly hiding this view?
I can't use removeFooterView() because I may need to show it again, in which case I can't call addFooterView() again because an adapter has already been set on the ListView, and you can't call addHeaderView() / addFooterView() after setting an adapter.
It seems that you are allowed to call addHeaderView() / addFooterView() after setAdapter() as long as you call one of those methods at least once before. That is a rather poor design decision from Google, so I filed an issue. Combine this with removeFooterView() and you have my solution.
+1 for the other two answers I got, they're valid (and arguably more correct) solutions. Mine, however, is the simplest, and I like simplicity, so I'll mark my own answer as accepted.
Try setting the footer's height to 0px or 1px before hiding it. Alternatively, wrap the footer view in a wrap_content height FrameLayout and hide/show the inner view, leaving the FrameLayout visible; the height should wrap properly then.
in my case addFooterView / removeFooterView() cause some artefacts.
And I found other solution. I used FrameLayout as FooterView. And when I want to add Footer I called mFrameFooter.addView(myFooter); and mFrameFooter.removeAllViews(); for remove.
FrameLayout frameLayout = new FrameLayout(this);
listView.addFooterView(frameLayout);
......
......
//For adding footerView
frameLayout.removeAllViews();
frameLayout.addView(mFooterView);
//For hide FooterView
frameLayout.removeAllViews();
The Droid-Fu library has a class designed for having a loading footer show and hide: ListAdapterWithProgress.
Works well in my project:
1.Add footer view first
mListView.addFooterView(mFooterView);
mListView.setAdapter(mAdapter);
2.Set visibility
mFooterView.setVisibility(View.GONE);
mFooterView.setPadding(0, 0, 0, 0);
3.Set invisibility
mFooterView.setVisibility(View.GONE);
mFooterView.setPadding(0, -1*mFooterView.getHeight(), 0, 0);
As #YoniSamlan pointed out, it can be achieved in a simple way. You have to specify
android:layout_height="wrap_content"
in the ViewGroup that contains the "Load More" button. Doesn't have to be FrameLayout, see below for a simple -working- example that uses a LinearLayout.
Both images show a screen that is scrolled all the way to the bottom. First one has a visible footer that wraps around the "load more" button. Second images shows that the footer collapses if you set button's visibility to GONE.
You can show again the footer (inside some callback) by changing the visibility:
loadMore.setVisibility(View.VISIBLE); // set to View.GONE to hide it again
Perform listView initialization as usual
// Find View, set empty View if needed
mListView = (ListView) root.findViewById(R.id.reservations_search_results);
mListView.setEmptyView(root.findViewById(R.id.search_reservations_list_empty));
// Instantiate footerView using a LayoutInflater and add to listView
footerView = ((LayoutInflater) getActivity().getSystemService(Context.LAYOUT_INFLATER_SERVICE))
.inflate(R.layout.load_more_footer_view, null, false);
// additionally, find the "load more button" inside the footer view
loadMore = footerView.findViewById(R.id.load_more);
loadMore.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
fetchData();
}
});
// add footer view to the list
mListView.addFooterView(footerView);
// after we're done setting the footerView, we can setAdapter
adapter = new ReservationsArrayAdapter(getActivity(), R.layout.list_item_reservations_search, reservationsList);
mListView.setAdapter(adapter);
load_more_footer_view.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<Button
android:id="#+id/load_more"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="9dp"
android:gravity="center"
android:layout_gravity="center"
android:background="#drawable/transparent_white_border"
android:textColor="#android:color/white"
android:text="#string/LOAD_MORE"/>
It should be a bug of Android.
You don't need to remove or add footer view dynamically. You just need to create an unspecified height parent Layout (either inflate it from an xml file or create it programatically) and then add your view which you want to hide or show into it.
And you can set the view, but NOT the parent Layout, to VISIBLE or GONE or something else now. It works for me.
Used
footer.removeAllViews();
This does not remove footer but flushes children.
You again have to repopulate children. Can check by
footer.getChildCount()<2
I also found that is possible call onContentChanged() (if you use ListActivity) to force recreate ListView if I need add HeaderView to them after setAdapter() call, but it is very ugly hack.
I have created a ListView that handles this. It also has an option to use the EndlessScrollListener I've created to handle endless listviews, that loads data until there's no more data to load.
You can see these classes here:
https://github.com/CyberEagle/OpenProjects/blob/master/android-projects/widgets/src/main/java/br/com/cybereagle/androidwidgets/helper/ListViewWithLoadingIndicatorHelper.java
- Helper to make it possible to use the features without extending from SimpleListViewWithLoadingIndicator.
https://github.com/CyberEagle/OpenProjects/blob/master/android-projects/widgets/src/main/java/br/com/cybereagle/androidwidgets/listener/EndlessScrollListener.java
- Listener that starts loading data when the user is about to reach the bottom of the ListView.
https://github.com/CyberEagle/OpenProjects/blob/master/android-projects/widgets/src/main/java/br/com/cybereagle/androidwidgets/view/SimpleListViewWithLoadingIndicator.java
- The EndlessListView. You can use this class directly or extend from it.
I have small hack way to resolve this problem for everywhere.
Put listview and footer view (just sub layout) in parent layout like LinnearLayout, remember that footerview below listview.
Controller this footer view gone and visibility like nomal view. And done!
first I am adding my footer to the listview,like this
listView.addFooterView(Utils.b);
Then on button click , I remove the view,
listView.removeFooterView(Utils.b);
I am adding the footer everytime when I am hitting the async,and theus the're no duplicate entry.I could aslo check for the count and so it like this,
if(listView.getFooterViewsCount() > 0){//if footer is added already do something}
When you want to remove the footer in ListView just call
listView.addFooterView(new View(yourContext));
It will add a dummy empty view which will not reserve any space
I have a LinearLayout View with a OnClickhandler and I want to add a View after the LinearLayout programatically when the OnClick event is fired.
public void onClick(View view) {
LayoutInflater li = (LayoutInflater) getSystemService(Context.LAYOUT_INFLATER_SERVICE);
LinearLayout info = (LinearLayout) li.inflate(R.layout.infolayer, null);
// view.addViewAfter(info)
}
info is the View i want to add. view is the View on which the click goes and after which I want to add info.
How can I do that?
IF u want add a view after the current linear layout then first get the id of the parent layout in which the linear layout is .
for example let u have the the Linear Layout with id "ll" in relative layout(having id parentlayout) and on a button click u want add the text view under the liner layout
public void onClick(View view) {
RelativeLayout rl=new RelativeLayout(this);
TextView tv=new TextView(this)
//set param value ur requirement
RelativeLayout.LayoutParams params = new RelativeLayout.LayoutParams(
LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
params.addRule(RelativeLayout.BELOW,R.id.ll);
}
Assuming you have a known amount of linearlayouts could you just place them inside the XML resource and mark them as 'GONE'. When the event occurs make them visible. When they are marked as gone they shouldnt be taking any screen space up.
You can insert through coding and you don't need to inflate. You can create a view of any type calling the constructor and passing the context. A reference to the context can be stored on the view as a field, when the view is being constructed. This way you can always create your view on the fly.
To add the view to the LinearLayout, you just need to call addView. And afterwards, if you would want to remove it, just call removeView.
But the onClick event is inside the LinearLayout object? This might be a problem because the views inside the the LinearLayout might consume the event before it reaches your method. See this post to learn about that.