android x navigation is not going back to host fragment when triggered from specific destionations
i tried lot of things but anything didn'twork for me
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My problem is illustrated by this screen record.
When I click the FAB on FinanceFragment, it will open AddTransactionFragment. But when I navigate to ReminderFragment and go back to FinanceFragment, the AddTransactionFragment is destroyed.
How could I -- similar to the YouTube app when one switches between fragments -- keep AddTransactionFragment visible while I navigate to another fragment?
I tried to add addToBackStack() but this turned out not to be what I was looking for.
I'm doing a nav graph in an Android project where I have a number of fragments - let's just assume for now that I have 3 (fragment A, B and C).
I have navigation actions between the fragment like this: A -> B, B -> C, and finially a global action always just pointing to A (Since the app is way bigger than 3 fragments and fragment A is a start screen, so it makes sense to have a global action going back to the start screen).
From fragment C I can go back to A with the global action (which is also using popUpTo and Inclusive, to clear the backstack totally).
Now the issue - I'm using transition animations when transitioning between the fragments and they work - except for the global action where I'm using popUpTo. I wish to use a from_left and to_right animation as enter/exit, which works exactly as intended on other fragments, but for the global action the exit animation is wrong (looks kinda like the fragment is moving out to the left of the screen instead of out to the right).
The weird thing is: If I set the popUpTo behaviour to "none", it works perfectly fine, animation plays as intended.
So, is there something one should be aware of about transition animations when using popUpTo in the nav graph?
I am currently trying to use the Android Navigation component to navigate from one fragment (A) to another (B) by animating fragment B up from the bottom of the screen (over fragment A) and subsequently animating fragment B back down when the back button is pressed. I currently have an action defined for this:
<action
android:id="#+id/action_landingFragment_to_bookingFragment"
app:destination="#id/bookingFragment"
app:enterAnim="#anim/booking_screen_in"
app:exitAnim="#anim/nothing"
app:popEnterAnim="#anim/nothing"
app:popExitAnim="#anim/booking_screen_out"
app:popUpTo="#id/landingFragment" />
However, when I navigate to fragment B from fragment A currently, I get a nice smooth slide up from the bottom of the screen, hit the back button and see fragment B disappear instantly to display fragment A again, with no animation. I currently use no custom code for the back button on fragment B (though I tried navigateUp() and popBackStack() in an OnBackPressedCallback to see if I was missing something regarding these. I also wonder if there is an issue with Z-axis of the fragments (similar to this thread) but my normal enter/exit animations work fine and I have tried a more traditional set of animations (slide left/right) in which the enter and exit animations play but the pop animations once again do not.
Can anyone suggest the correct way to do back navigation such that these pop animations should be visible?
My Action bar consists of two tabs (a list of businesses and a map of businesses). If someone chooses from the list I would like to hide the tabs and show that business' page. If the user hits back, the business fragment is popped and the tabs should be displayed again.
What is the best approach to get this working? So far with the following code I have an inexplicable recursive loop if I pop the business fragment :(
So picture this, I'm displaying the BusinessListFragment tab. I choose a business, swap fragments and in onPause() I set the navigation mode to standard. Hit the back key, and in the onResume() of the BusinessListFragment I have this:
ActionBar ab = mHostingActivity.getSupportActionBar();
if (ab.getNavigationMode() == ActionBar.NAVIGATION_MODE_STANDARD)
ab.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);
Which is supposed to bring back the tabs, but the app freezes with a loop. The tabs are definitely still present. Maybe I'm doing something else strange in my code (I'm sure I'm not though), or maybe Android does something strange when the naviagtion mode is set?
Edit: I've learnt that simply setting the navigation mode to tabs seems to actually select the first tab - which I believe would explain the recursion. Interesting!
Okay well this took a while to figure out but hopefully this will help future googlers :D
It seems the best practice is to never try and hide / show tabs by setting the navigation mode from within a tab fragment's onResume / onPause, or anywhere within it for that matter.
I therefore set the mode to Standard in the onResume() of the detail (business) fragment. Normally if there are no more hierarchical layers of navigation to traverse from within the detail fragment, it is fine to simply set the mode back to Tabs in the detail fragment's onPause() - accounting for back presses or up presses.
However in my case you can click on elements within the business page to launch another fragment (leaving a stack count of 3), meaning I cannot 'turn on' tabs within onPause(), and found the best solution was to do it within onDetach(). This should mean the tabs are only turned on when the detail fragment is actually popped from the stack.
Hopefully this solution is accurate, I have toyed with many ideas including back stack listeners and overriding onBackPressed, but for me this seems to be the best option.
I am creating an app for Android 3.0+ that uses the action bar with tabs for navigation. I have 2 tabs that each load a ListFragment:
Tab 1 Tab2
A B
C D
Where A & C are list items in Tab 1 and B & D are list items in Tab 2.
Currently if you select Tab2 and then item B a new ListFragment is loaded on top of the current list fragment in Tab2. Pressing back takes you back to the original Tab2 contents. However if you don't press back and instead select Tab1 you see Tab1's contents on top of the new content you loaded in Tab 2. So I am guessing there is a better way of doing this. I wanted to use multiple fragments in each Tab to reduce the code complexity in each tab (for instance the onListItemSelected handling). Is there another way to do that without using multiple fragments? I am also trying to just save state but I am not sure how to tell the difference from when the user clicks back (then I would want to restore state) and the user has selected tab 1 and then selects tab 2 again (i would want to restore state).
Thanks
I am having similar struggles with the complexity of fragments and tabs on the Action bar. It seems to me that android for tablets is still very much in its infancy and there are various issues (like yours and the issues I'm having) that will be addressed in the coming months. For now, I think you just have to handle some of those complexities yourself instead of relying on the Android framework.
To answer your first question more directly, I think you need to step back and think out the functionality before diving into the code. I can give you a potential solution (keep track of your fragments manually in the activity and simply add and remove fragment as necessary via the ActionBar.TabListener interface.
Also, if you want the user to be switching from one fragment to another like you are suggesting, perhaps the back functionality shouldn't be used. What happens if the user clicks on the tabs 10 times in a row. Do you want the back button to take the user back through all of those events? I think the back button should only be used when the navigation system is very sequential and "back" is an easy concept. Check out all the Google apps that use tabs to see what I'm talking about.