I followed instruction for actionbar Tab from here
I'd like to user to be able to scroll back to top of list-view when they reselect a tab.
I put listView.setSelection(0) inside onTabReselected(Tab,FragmentTransaction) method.
It works as intended when I re-click the tab already chosen.
But the function is also called when I didn't expect it to be.
I start a new activity.
When I come back to the original activity(with the tab), the onTabReselected function is called.
How can I differentiate the two cases so that I don't scroll the list when coming back from another activity?
The unexpected call to onTabReselected was due to my setSelectedNavigationItem call in onResume.
problem solved.
Related
I am currently writing a drawer layout as my main layout, with an embedded FrameLayout that I will be using to hold each “page” when an item on the drawer is clicked on. When the app first starts, an initial fragment will be show. Other fragments may be added/replaced later which is fine, however, my problem is that when the user clicks the back button on the very first “initial fragment”, I don’t want that particular fragment to be removed from the layout. Currently, it is being removed and it’s just showing a drawer layout with no other content (which makes sense). I want the app to automatically exit if the initial fragment was the last one showing and the back button is pressed, instead of removing that initial fragment and then after another back press, then it exits.
Things I have thought of doing:
Not adding the first fragment to the backstack. (If I do this, I can compare it with the classname of the fragment which is a somewhat longer string, or I can use a boolean value for once the first fragment has been placed (and not added to backstack), the boolean is set which allows the fragments to now be added.
Overriding the onBackPressed function of the activity
Does anyone have a suggested way of doing this or can think of a better way? Thanks
The first bullet point sounds the cleanest. You have no other need to handle conditions when back is hit, correct? If that's the case, it's less lines of code (removing one as opposed to adding several) and you get to keep default Activity methods as is.
I know that's not exactly what you asked, but I think the first bullet point is so clean, that I just wouldn't try something else.
I have implemented same in one of the app using my own Stack of fragment. and also implemented onBackPressed method.
Every time when user clicks on item in drawer i add fragment in stack and in back press once its length is 1 I finish the activity with message.
On item click -- Add/replace fragment in container.
OnBackPressed -- Pop fragments from stack and once its last one i finish activity.
Hope this can give you another option to consider.
I need my first tab, when I select it (after select the second), to call its onCreateView() or just its onResume(), or another function, to update it.
I have 2 tabs, what I do in the second tab have to change something in the first tab. But, when I'm in the first tab and I select the second, the onCreateView() of the first is called again. So, if I do something in the second tab and return to the first, nothing changes. To update the first, I had to go to the second again, to it call the onCreateView() of the first and then I have it updated.
I need the first tab to update itself when I select it, not when I select the second tab. I already tried the ViewPager.setOffscreenPageLimit(0), with no success.
How can I make it work?
I'm assuming here that you're using a ViewPager. The reason setOffsetPageLimit(0) doesn't work is because 1 is the minimum value here.
You should create a callback that your Activity (or a class which can access both Fragments) implements, which the second Fragment can tell to update. You can then do logic in that callback to update your first Fragment.
I'd advise not doing the update in onCreateView() as you've mentioned because then it ties updates to the Fragment lifecycle - which is tricky to control.
I have this Android architecture:
Activity that has an action bar with two tabs.
each tab is a fragment
my problem is, when i start the activity, the two tabs start working.
I don't want the second tab to start working unless i click on it.
How please?
note that i am using onCreateView on my second fragment
note
i tried to make my functions on onResume() but still fires itself
This comes from caching of the ViewPager : it will initiate the visible fragment and one on each side (left and right). There is no thing you can do against that. The method setOffscreenPageLimit will refuse a value below 1.
So the solution is to fire your own even to actually "start" your fragment when it becomes visible. Don't use the fragment lifecycle per say, but add a custom method : startBeingVisible().
To fire this custom event, you can just use an OnPageChangeListener.
I created the below project so you can see my exact code and what is going on:
https://github.com/CorradoDev/TabsTest/commit/8f054dab2371b791c4061ceb511413f720f65d67
Basically what I am trying to do is hide the tabs for some pages and show them in other pages.
Below is the code I am using to show the tabs in the onresume
if(getActivity().getActionBar().getNavigationMode()==ActionBar.NAVIGATION_MODE_STANDARD){
getActivity().getActionBar().setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
}
THen to hide the tabs I am doing the below on resume:
getActivity().getActionBar().setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
When I am on the first fragment(nothing in backstack). I can show and hide the tabs on hte second. It gives errors sometimes with changing tabs.
When I am on the second fragment in the backstack and I hide the third fragment. I see the second and third fragment both call the onrefresh but the third fragment does not show.
I am confused on what is going on and why this is not easier.
Below is the error I generally get
03-27 15:26:31.029: E/AndroidRuntime(5505): java.lang.IllegalStateException: Fragment already added: Fragment3{41f2e390 #2 id=0x1020002 fragment3}
I still would like to know why the above does not work. But my fix was to create another activity with the fragment and no tabs. That seems to work well. But I am interested if they did not intend you to change tabs and no tabs per fragment.
I had a similar situation - only that I used NAVIGATION_MODE_LIST instead of tabs. I run into similar issues when I called a fragment from another fragment e.g. click on a list item opening up the item details.
Now I call all fragments from the main activity which allows me to control the set up of the actionbar. Whenever the navigation list should disappear I just call NAVIGATION_MODE_STANDARD when the fragment is called and NAVIGATION_MODE_LIST for the other fragments.
I have used 2 tabs in my app.
when i click on first tab it is showing an list view( default) and when i click on any particular item in list view it is taking me to the next activity to display the selected data. Here when i click on tab again i want that i should go to the listview screen which is default screen.
but nothing happens on clicking the tab but when i press the back button i m going back on the screen. but i want to go to home list view screen on tab click,
pls help me in this case...
You say you start a new Activity. This one can not call the first Activity where you have the tabs. Am I right that your new activity just shows the two tabs as well?
What you could do is the following:
In the second Activity react to the onclick of the tab. When clicked call finish() to close the Activity.
I am pretty sure, that you don't need to do the following. But I write it, if you need it for something in the future :).
In the first Activity call the next through startActivityForResult(...)
In the first Activity overwrite the onActivityResult method. there you can switch to the tab with the list.