Code to reproduce and test: https://snack.expo.io/@angelikaserwa/humiliated-bagel.
Switch to the Settings tab, then go back to the Home tab and press the details button. Nothing happens. It was because after re-attaching we were using a destroyed FragmentManager that was cached inside the ScreenContainer class.
Then, when we go back from Details to Home screen, using a hardware back button, an exception occured: `The specified child already has a parent. You must call removeView() on the child's parent first`.
I fixed this by calling `removeAllViews()` when detaching container from window and forcing an update on re-attach.
This change fixes the problem when header update would get triggered while the header config subviews are not yet fully unmounted. The root cause of this problem is kind of a mystery, I encouneter a crash when going back using back button from a screen that have custom back button image rendered. Turned out that after implementing removeAll schema the problem no longer occurs. I didn't have enough time to investigate it further but supporting removeAll schema is an improvement regardless so going with this solution for now.
Appear event is used by react-navigation to properly dispatch focus. It is important that appear is dispatched after dismissed event. The reverse order of actions would result in getting react-navigation stack in a weird state.
It is relatively streightforward to implement onAppear event on iOS where we hook into didAppear callback from UIViewController. It gets dispatched in the right moment, that is when the transition is fully over.
On Android however it is much more tricky. There is no standard way to be notified from the fragment level that fragment transition finished. One way that is frequently recommended is to override Fragment.onCreateAnimation. However, this only works when custom transitions are provided (e.g. if we set the transition to use fade animation). As we want the platform native transition to be run by default we had to look for other ways. The current approach relies on fragment container's callbacks startViewTransition and endViewTransition, with the latter being triggered once the animation is over. We also need to take into account that a good starting point for the transition is when we call commit on fragment transaction. We use these two methods to determine if the fragment is instantiated (onCreate) within a running transaction and if so we schedule event dispatch at the moment when endViewTransition is called.
Another change this commit introduces on the Android side is that we no longer rely on show/hide for replacing fragments on stack and we now use add/remove transaction methods. Due to this change we had to make our fragments reusable and make onCreateView indempotent.
This change fixes the problem when there are changes being made to the stack while the hosting activity is in paused state (e.g. an activity-based dialog from google play services). In such a case it is not allowed to do any changes which can affect fragment manager's state (e.g. updating backstack). For other changes we use `commitAllowingStatLoss` to indicate we are not interested in fragment manager handling their restoration and hence we can perform most operations. Unfortunately installing back handler is not allowed without state change and we need to wait until the fragment host is resumed before we install it.
This change fixes the issue of handling transparent status bar. In such a case the navbar should became slightly bigger in order to fill the status bar space that now belongs to the window. In order for that to happen we use `setFitsSystemWindows` on main screen layout, on app bar layout and on toolbar (the toolbar is the view that gets bigger in the end).
Note that this currently only work if we use Android's native mechanism for changingthe status bar behavior and not using `StatusBar` module from RN. It is because `StausBar` module actually strips top insets from the event that gets delivered to the views. For the time being you can try the following to change status bar:
```
getWindow().getDecorView().setSystemUiVisibility(View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN);
```
Note that we are also disabling app bar's scroll behavior. We wasn't utilising this yet, and it cause some weird errors on hot reload because scrolling behavior actually sets `firsSystemWindows` flag on the screen view which ended up consuming insets before appbar would get them.
This change fixes two issues related to stack nesting on Android.
First one being the fact that root and nested fragments were relying on the same fragment manager as opposed to using nested fragment manager structure (via getChildFragmentManager). This resulted in an unprodictable behavior when displaying the top screen. This commit changes this behavior by correctly returning child fragment manager or root fragment manager depending on the containers hierarchy.
Second issue was related to back stack handling and resulted in always the root fragment manager interacting. Instead we want the bottommost active stack to handle back presses. This has been addressed by adding `setPrimaryNavigationFragment` when creating back stack entries.
There was an issue with back stack listener being triggered after reload caused by the fact we weren't cleaning up stack manager's back stack on reload. As a result after reload listener would get triggered with and empty stack first and only then with a back stack with 1 item. Consequence of the first trigger was that we'd call dismiss and move back from the top screen which wasn't a desirable behavior.
This is a similar fix to the one already merged in #215 but for Android this time. We change default screen container to layout its direct children without using flexbox. This is to follow the same pattern as with native stack container.
Before this change we'd rely on new androidx OnBackPressedCallback mechanism. It turns out not to work well in a few cases. The biggest problem with it was that when registered it'd never allow for the hw back button press to fallback to a system default behaviour and instead would always "still" that event. After several attempts of trying to make it work I decided to revert back to a FragmentManager's default solution.
This change adds an ability to use FragmentManager's back stack API. There are also a few problems with it we need to workaround though. One of the problem is the fact that we can not modify back stack history. What we do because of that is that we try to keep at most one item on the back stack and reset it each time our native stack updates. In order for that to work we create a fake transaction that hides and shows the same screen that displays on top. Thanks to that when hw back is pressed the built in transaction rollback logic does nothing to the UI and allows us to handle back navigation using back stack change listener.
A few bugs fixed with android native stack in this commit:
- fixed a problem with views not resizing when keyboard appears, the bug was due to onMeasure forwardin getHeight which was the old height of the container instead of the changed one
- fixed a problem with back button behavior not being consistent. Now back button is controlled by 'gestureEnabled' to emulate iOS behavior where there is no hw back button but you can swipe back instead.
- added compatibility for "contained" modal styles - for now we always render "containted" fragments on Android, plan to add a way to render in dialogs in the future
* Let UINavController control subcontroller view's frames.
This PR changes the way we've been handling yoga <> NavController layout interactions. Now we ignore frame updates coming from react for the main Screen view to allow NavController take the controll. In order to keep yoga working we now use `setSize` to pass the dimensions of the view back to yoga such that it can properly calculate layout of the views under Screen component.
* Header resizing fixes for Android.
In this change we use CoordinatorLayout as a stack screen container to handle rendering of toolbar and screen content. Thanks to this approach we can support collapsable bars in the future. Instead of relying on RN to layout screen container when renered under ScreenStack we rely on Android native layout to measure and position screen content and then use UIManager.setNodeSize to communicate that back to react.
