I know Android execute 2 times (or sometimes even more) the getView() method of the adapter in order to draw the ListView correctly. I would like to know (or get notified) when it stops execute that method.
Why? The rows of my list are animated when user swipes on one of them. If the user swipes before Android has finished execute getView(), the animation is executed on the first row instead of the row touched by the user.
You can load ListView in background AsyncTask. And during that time you can show progress dialog on the screen so user is not able to do any action on your screen.
Check this Reference :
Load ListView in background AsyncTask
Hope this helps you.
Thanks.
There is no last getView()
When you are scrolling in a list, for each item that will become visible a getView() will be called. EVEN when it has already been on screen. I believe you are not detecting the list view item click properly.
Related
I have a situation involving animation of listview's item appearances.
I have a few views in a ScollView , the last of which is the listview. I have attached an appearence animation of the row (a fade in animation).
The problem I have is that when the screen is loaded , the getView() of listview already executes for the initial items , even though the listview is not currently in view.
Hence when a user scroll downs , he sees the list plainly.
I am unsure how to go about this situation . Is there any callback that can be invoked when a row from a listview becomes visible on screen ? .
Yes there is a callback (OnScrollChangeListener), first visible index and last visible index etc. You can achieve what you are trying to using combination of these.
But you need to try that yourself first. No one can simply write a code for you.
You can learn about listview here
I have a grid view when user presses a button i am changing grid view data and setting adapter again now on item click is not working but Touch listener is working WHY ?
I have two types of adapters when user presses button a i am setting first adapter when user presses button b i am setting second adapter data is changing but on item click not working?
Try to use AsyncTask (http://developer.android.com/reference/android/os/AsyncTask.html).
Because this kind of updates is always a problem, you have to do your adapter's update in onProgressUpdate or onPostExecute.
So, when your button is pressed, you execute your AsyncTask.
I know this is old, but maybe somebody else will seek for answers...
Anyway, I had a same issue and wasn't able to figure out why my onItemClick() didn't work. Instead of implementing onItemClick() inside your adapter, try doing it with adapter.setOnItemClickListener(). It worked for me ;)
I have 2 different adapter for a ListView. Both adapters extends BaseAdapter.
I have 2 Button in the header view of the ListView.
Button 1 call ListView.setAdapter(adapter1);
Button 2 call ListView.setAdapter(adapter2);
The first time I click either one of the button. The ListView update to another adapter view immediately.
However, the second time I click either one of the button. The Button listener will not trigger until I scroll the ListView.
I have tried to put a toast inside the button listener. The toast is only called after I scroll the ListView.
Anyone have any idea what is the problem?
The UI in Android is efficient and will only update when it NEEDS to. In the case of your list the UI only updates when you scroll it because it needs to fetch more items for the list. To force an update you need to call invalidate() on your ListView.
I want my ListView to work something like the following:
When I press a button (probably from context-menu), I want the user to be able to select more then one item from ListView (probably using check-boxes), but those check-boxes should not be visible before that.
So, the point is, after the user presses a button (let's say "Delete more items"), the listview, should update itself, and appear on every row of the list, a checkbox should appear (allowing me to select the items ID to pass those to server).
How can I achieve that, without having to recreate the list from zero? (how to setVisibility ON, keeping the other content of the ListView as it is, and not doing another request to server).
PS. If you guys, have another better idea, on achieving the Delete More Items, would be much appreciated!
This is just an idea, haven't tried it myself: you build in a checkbox in your listitem layout. Normally, in the getView of your adapter, you set it invisible with
checkBox.setVisibility(8);
When you want to show them, you set some boolean
showBoxes
of your adapter to true, then in the getView oyu don't hide the checkboxes.
Then
notifyDataSetChanged
on the adapter.
Hope it's clear what I mean.
I need all of the other views in my arrayadapter to check their attributes and return to a default attribute at certain times
use case: listview items (a)(b)(c)(d) , when you touch (a) it's background turns black. This is done in the ontouchListener. But when you touch view (b) it's background turns black BUT (a)'s needs to turn back to the default which is not black
I dabbled around with recalling the arrayadapter at the end of the view.OnClickListener but the problem with this is that it also resets the scroll position of the view, so if this list was much longer - which it is - and user touched item (r) , then it would reset the list and put the user back at item (a) at the top
I was looking at notifydatasetchangedbut I am not sure how to use that and where it should work
insight appreciated
notifyDataSetChanged will do the job. You can call that at any time in your code and this will trigger the adapter to call getView for the visible list items again and so update their content. So basically the only thing you have to do is to update the list item states or information before calling that method.