I vaguely understand what fragments are used for. However, I don't understand why ADT seems to suggest that we should ALWAYS use them. I am aware that I can simply delete the fragment layout, as well as the code in Activity for the fragment. But is it ACTUALLY recommended to use fragments all the time? What are the benefits of not deleting it?
Is there even a point of an Activity having a single fragment? What is the difference with it having no fragments at all?
Additionally, how do you know whether to create multiple fragments in one Activity, multiple Activities with a single or zero fragments or a combination of Activities and fragments?
For example, if you have a Terms and Conditions button in your Activity, and you want it to open a screen containing a document listing the terms and conditions, should I be starting a new Activity for that? Or should I just move a fragment containing this content to the front?
Using Fragments is how modern apps are developed today.
Some of the benefits are a better performance when switching content (lets say 2 fragments)
because you are not leaving the current Activity.
Also, apps with swipe tabs (for example) are built with an Activity as a container and Fragments as the content itself.
Other benefit is that you can do much more with one activity, distributing work between the fragments. Each Fragment have its own Layout and therefore its own components, so maintaining the code and keeping organized is easier.
Eclipse does this way as suggesting a start point. You can totally ignore this and start from scratch. And that's all.
I suggest you to keep the Fragment to start getting used to it. Even if there is just one.
And, if later you need to work more with that Activity, it will be easier to add new features by creating a new Fragment, without modifying your previous code.
Good luck.
Related
I'm trying to make an app and I have made a blueprint for a specific activity, but I don't know how to implement it. The layout contains few buttons at the top of the activity, and each button features some information, which is displayed inside the view. The view which needs to be updated is present under the buttons. I don't want the activity to be changed, instead it should update the contents of the View, which is different for each category/button.
By doing some research I have realised that the "Tab Layout" can be used to achieve my requirements, but I don't want the tabs and I need some stylish buttons as a replacement.
I know I'm not the best at describing, so I have looked upon Dribble and found one design which is 100% similar to blueprint.
I want to achieve this using XML and Java using Android Studio! Every suggestion will be a great support foy my app.
Thanks a lot.
As far as I know, you could achieve that by using fragments (which is the same concept you would have used on TabLayout). I don't really know how much knowleadge you have on Android, but if you know what a Fragment is, it should be easy for you to recreate the idea.
You have 3 buttons for 3 different fragments, so you must design every fragment by separate and change it depending the button you click.
I am new in Android so correct me if i am wrong. When another activity is opened, the first one is destroyed. So i have to pass all variables to the new activty if i don't want to lose the data. Or, can I run another not UI thread that manages my data?
Basically I need to change layout in my app on button click. Is there any way to do it within the same activity or i have to start another activity with the new layout?
You can use one activity in your app and do what you want in fragments. Navigation is good tool to use for relating fragments to each other.
well initially you can use a single activity and in that activity you can call multiple fragments as per your need,
and for the data you can use MVVM architecture with room architecture, it saves your lots of time and code.
and go with navigation graph if you want a quick and easy implementation.
you can start all this with this demo.
Hello i am fairly new to android development and have been using Activities to navigate through my app. Now that i have gotten my feet wet i'd like to write more efficient applications. From what i have read, fragments are a way to limit the creation of unnecessary Activities and reuse UI elements.
I am trying reduce the amount of activities in my applications by converting them to fragments. When a button is clicked, do i call the next fragment from the current fragment, is this good or bad practice? What is the role of the main activity if fragments are directing the flow of the application?
Fragment is good practice but you need more careful handling fragment because it's tight coupling is when a group of classes are highly dependent on one another.
read this tutorial it will help to understand fragment flow [https://guides.codepath.com/android/creating-and-using-fragments]
Fragment is view and Activity is parent View (MainController is must be actvity)
So I have a TabActivity that branches into three sub-activities (tabs). One of these activities is a ListView, which I want to branch into further ListView activities. However, I want each of these branched ListViews to also have the same tabs at the top. To do this, do I need to create a separate TabActivity and a separate Activity for each of these branched ListViews? Or is there an easier way?
Cannot you trick a user into having TabActivities, but instead simply have one ListView instance with 3 buttons on the top of an activity (Tabs) and every time user clicks one of the "fake" tabs, just refresh the existing ListView with views that are appropriate for one of those "fake" tabs. In my opinion this solution would be more efficient resource-wise and render time -wise (which anyway are dual concepts)
This is what I have in mind
You may use Fragments as proposed by MaciejGórski for TabActivityOne, TabActivityTwo and TabActivityThree, while the ListView inflation technique could still be used
Switch from the old deprecated APIs using like TabActivity or ActivityGroup into Fragments.
This class was deprecated in API level 13.
New applications should use Fragments instead of this class; to continue to run on older devices, you can use the v4 support library which provides a version of the Fragment API that is compatible down to DONUT.
From TabActivity documentation.
I'm implementing a fragment hierarchy similar to the one described in Fragments (Android Developers).
In adition in tablets in portrait the app should behave as in the second case. My problem is to handle the transaction from an orientation to other.
The first idea I considered was:
From landscape-to-portrait:When the activity A goes to portrait: Remove the fragment B to the view. Start activity B for result passing the propper values for recover the original fragment B state
From portrait-to-landscape: When the activity B goes to portrait. finishes (with the fragment 2 status in the result). The activity A with the result restores and adds the fragment B to its layout.
But this solution is pretty complex and I think it provably is not a nice idea. The alternative solution I have considered is only to have an Activity. That activity layout is:
<FrameLayout>
<LinearLayout>
<Fragment A>
<Fragment B>
<Slot>
For small devices:
The app removes the fragment B and when a item is selected add to the backstack the fragment to the "Slot"
For tablets:
Using fragmentTransactions the fragment B is moved from Its position to the "Slot" using the backstack to behave properly to the orientation changes
I think the second option sounds better but, is the correct way of doing this?
Thanks
If you want my advice, I'd say it depends on way too much factors. I think you should stick with what you find manageable enough. It depends too on how complex your app's screen flow is.
Keeping it in one activity is, for me, a good idea if you don't have that much fragments to manage. An advantage of this approach is that you don't need to fiddle around with the life cycle of two different activities.
Anyway, finding the implementation complex is in a way an indicator that what you're planning won't be manageable for you in the future.
Hope that helps!
I dont get why would you want to do it in such a complicated way. Have one activity on tablets, two activites on phone. Have first activity implement a listener that would fire if list fragment's item was clicked. The activity knows if it is inside single or dual pane mode, so inside that onItemSelected callback method, have it either start a new activity in case of a single pane mode, or replace a fragment, in case of a tablet.
You can also see this, using Master/Detail template when creating a new project.