FloatingActionButton | Android floating action button | Frontend Framework library

I have an application under construction using the Navigation Drawer Activity which is the one with the left menu like the old version of Google PlayStore:

As you know the design comes bundled with a FAB (FloatingActionButton):

Now, in the left side menu you see these three Fragments:

I wanted to know, how do I assign different actions to the FAB when I change the Fragment? From the MainActivity I see that there is the k but I do not understand how to assign a different functionality to it, since when changing the Fragment, the same FAB is still there and executes the same action that in this case is a Toast:

I need to implement the below layout for my RecyclerView Items (The picture represents two rows):

This is my XML file:

I'm trying to show all user posts that the user who is using the app follows, and I'm using Firestore. I take all the ids and put them on an arraylist and build a query. I am using FirebaseRecyclerView but I have this error:

How to create BottomNavigation with one of the item is larger than the parent, but without using floatingActionButton. For example like this:

I tried to do that by wrapping the icon with Box but it get cut like this:

Then i try to separate that one button and use constraintLayout to position it, but the constraintLayout cover the screen like this. Even when i color it using Color.Transparent, it always feels like Color.White (i dont know why Color.Transparent never work for me). In this picture i give it Red color for clarity reason.

So how to do this kind of bottomNavBar without having to create heavy-custom-composable?

Update: so i try to make the code based on MARSK and Dharman comment (thanks btw). This is what i

I have a fragment that asks the user to enter subjects which will then be saved into a Spinner. The problem is that when I press add, nothing happens. I have a toast message to check if it's added or not and neither shows. I believe I'm doing something wrong because I have a fragment and the code might be different from what I'm used to. I have nothing relating to this in my MainActivity class. I'm a beginner so I don't understand much, any help would be appreciated, thanks.

Code for my Fragment:

I am learning flutter, and I would like to know how to pass a variable or a method between 2 different files (to add additional widgets). In my example, I took the code provided by flutter when we create a new project, to this code, I added a second file called "second.dart" in which I get the variable "_counter" in the file main "main.dart" which I multiply by 10.

main.dart

I'm trying to get the value from the TextField then compare it to a string = '123'

If the value = '123' then alert 'Successful!' or else alert 'Failed!'

Here is my code:

I am writing a similar task manager app, i have some issues when working with BLoC:

• First, I create a Page to show all the task that have been added by pressing the FloatingActionButton() below.

• Next, when the user finished the form by hitting the FlatButton on the top right which is called SAVE, it will be submitted to Firestore, by the _submit() method in the JobForm class.

• NOTE: I also added some validator to validate the NameForm and the RatePerHourForm so it will show an error when they are null and they worked very well.

• I used a StreamBuilder() to update my JobPage() ( the first screen ), everywhen the data from Firestore changed.

• That was a summary of what I am trying to do.

BUT, when the user press the SAVE button, the Name Field and the ratePerHour Field is always empty even when i called onChanged: , in every TextField() to update them.

HERE IS MY flutter doctor:

I have this mEpisodeList which is an ArrayList inside this class TvShowEpisodeLoader I also have another class named TvShowEpisodeDetailsFragment I want to access mEpisodeListfrom TvShowEpisodeDetailsFragment I want to get mEpisode (which is the number of the episodes of a season of a tv show) and display all available episode numbers in a horizonal scrollbar in episode_details layout and upon tapping on a number it will switch to that episode

here is TvShowEpisodeLoader , TvShowEpisodeDetailsFragment

mEpisodeList

here is the code