lets say I have master/detail pattern using fragments, so as usual, the detail fragment would be inside new activity on a phone and on a tablet it would be inside the previous activity that list fragment is in also. Old stuff.
I have some actions to perform on the detail, like share, it would be actionbar item. Old stuff.
But now, I want to implement Contextual ActionBar, or a dialog, it doesnt really matter in my opinion, that would allow sharing right from the list.
My question is, where should I have that sharing code? I want to avoid duplicates. In my head, it cant really be a callback because the detail can be inside the dual activity or inside its single activity. Its just really confusing to me how should I do this.
Hope you get it. Thanks!
where should I have that sharing code? I want to avoid duplicates
Taking a guess that "that sharing code" is your ACTION_SEND invocation, since that is only a half-dozen lines of code or so, tuck that in a static method somewhere that can be accessed by your detail fragment and by the activity that is hosting the list on smaller screens.
Related
New to Android. Trying to understand the technical downside of a design.
I have an ItemSelectorView which has both an availableItems collection as well as a selectedItem property. The latter is displayed at runtime along with a chevron letting the user know they can change it.
Functionality-wise, it's similar to a spinner except rather than showing a pop-up with the choices, it launches a second activity called ItemSelectorActivity which shows all of the available items from the ItemSelectorView which launched it, as well as helpful information about what each option means as well as the ability to search and filter.
When a user selects one, their choice is then returned back to the originating ItemSelectorView via a trip through MainActivity's onActivityResult override. The override then figures out which ItemSelectorView it's responding to and forwards it along.
However, I really didn't like the way MainActivity had to insert itself into the process just to get the result from ItemSelectorActivity. Plus, if ItemSelectorView was used in a fragment, things become more complex trying to forward the information to the correct view.
Because of this, I instead changed ItemSelectorView to ItemSelectorFragment which can override its own onActivityResult making it, not its owning activity, responsible for updating itself with the selected result. This means it's essentially completely self-contained now.
While this seems to work wonderfully--with this change a user only needs to place the ItemSelectorFragment somewhere in their layout and set the available and selected items--a veteran Android developer here said using a fragment like that was wrong and I should have stayed with a view because of the overhead of fragments.
But going back to a view means I'm back to having to get MainActivity involved again, making this much more complex to actually use.
So what is the technical down-side for using fragments like this? I thought that was the entire point of why they exist. And if I am supposed to use a view, is there an easier way to get a result from ItemSelectorActivity?
If I understand you correctly, your view is starting an activity (ItemSelectorView starts ItemSelectorActivity). But views should be dump in Android. They should display, nothing more.
So a view should never start an activity. A view can contain a list of items maybe, but these items should be views and nothing else. Usually we use an Adapter for that: a middle man between the items to be displayed and the views that are created to represent them on the screen.
You could look into MVP to do this in a proper way. Or maybe MVVM and android architecture, if you like that better.
To answer your question, using a fragment for your use case is a better approach then a view and there is not that much overhead at all.
I have a question about the correct logical use of fragments in Android. I know that it was designed to be used to improve tablet experience, but does this imply that fragments should generally ONLY be used for this purpose? Or would it be poor development practice to use fragments as a replacement for a custom compound View?
For example, I am writing an app to keep tally. When the score sheet is produced, it creates a "ScoreCell," a custom compound control, for each player in a ScrollView. What I want to do(but don't see how as a View) is handle internal OnClickListeners that are activated by the containing activity: each ScoreCell has a TextView for the players' name, which I want to long-press to startActivityForResult() to pop open an input dialog to change the name of the ScoreCell. But seeing as the method for OnActivityResult() is unavailable in a View, would it be correct for me to instead make each ScoreCell a fragment?
Here is a picture of the activity to help understand the logic of what I need/am confused about
There are many questions in here, let me go through them.
No fragments are not meant just for tablet experience, in general they allow you to create more modular and adaptable layouts (think classes). They are extremely helpful in tablet layouts/landscape, but also give you reusable components.
At the same time, a fragment is not the right choice here... It is much easier to use a listview, coupled with a custom cell layout. Instead of using another activity to display a dialog simply call new Dialog() and dialog.show(). An activity should only be used as a dialog if it will be used by the user by a long period of time and provides a new "activity" (action)
Items in a list should not each be their own fragment, no. You can pop up a dialog without creating an entire Activity. Take a look at the documentation on AlertDialogs and DialogFragments for your dialogs and you can get the result from that.
I have seen a few questions raised on this topic (for e.g.: https://github.com/jfeinstein10/SlidingMenu/issues/5) but I am still unclear. I hope somebody can clarify this.
Context:
See https://github.com/jfeinstein10/SlidingMenu
I have an android app that organizes screens by activities and fragments (i.e.) each screen is an activity containing one or more fragments.
The new requirement is to add a sliding menu (similar to what this library provides).
Issue:
It appears from the examples and discussion that the right model would be to have just 1 MAIN ACTIVITY that will then switch in/out fragments belonging to the different screens. In fact the author mentions in the above thread: "If you were to launch Activities based upon the list selection, then you would not have the behavior where you swap the views that you're talking about. " and also "You can't put an Activity into the above view. That doesn't really make sense when you think about what an Activity is. ".
Why doesn't it make sense? Obviously, I am missing the point here.
Question:
Given that my project already contains multiple activities (one corresponding to each screen), is my only option then to re-organize the project to have JUST 1 MAIN ACTIVITY, in order to use this library? Or alternatively, is there any way to launch a new activity when a list item in the sliding menu is clicked, and still observe the sliding menu behavior, [EDIT- added the last part to be more clear] or in other words, on how exactly to use this library within my existing app design.
Thanks in advance
First, you can't have an Activity inside another and activities are completely different from views as stated in the docs:
An activity is a single, focused thing that the user can do.
Now, to answer your question, it all depends on how you want your app to behave. You could have your activities with the sliding menu implement the onClosedListener and switch to the selected activity from there. This will give you the animation of closing the menu before switching activities. It will also give you a weird effect since every time you select something from your menu you'll see the animation of a new activity coming to the front.
I think the best approach would be to have a "common purpose" between all your sliding menu options. For example, in one of my projects I have to allow the users to select between lists of different types of data. When the user selects anything from the menu, I load a new list fragment into the right corner where he may choose the item he wants to view or edit. That's the app entry point and also the only place were I have a sliding menu in my app. It is pretty much the same for every app that implements this UI design pattern. Look at google+, currents and youtube where the side menu lets you choose which feed or content to show. Once a user makes a selection, just open a new activity for the selected item (a g+ post, a video, a news article, a tweet or whatever it is).
Your app doesn't have to have lists of different data or anything like that to use the sliding menu, but keep in mind that the activity with the sliding menu should have a clear, focused goal with respect to its functionality and purpose. Having a sliding menu because many other apps have one is a bad choice, you should use it with a specific objective. Also keep in mind that applying the sliding menu everywhere would interfere with the platform's navigation pattern and lead to an overall bad user experience since it wouldn't behave as the other apps.
It doesn't make sense to place an Activity into the above view because the Activity is the main controller for the view of each screen. The Activity also shows views and keeps track of Fragments (which in turn are mini controllers, with or without their own views). So placing an Activity in the above view would mean that you would place an Activity in an Activity... Wich is impossible.
From what I can derive from your text I think it would be wise to read through the Android developer guide on Activities and Fragment again (http://developer.android.com/guide/components/activities.html) to get a better understanding of how the concept of Android works.
Now to your question:
I am not clear on what you are trying to achieve but if you want your app, with menu to behave like, say, the Google+ app then one way of doing it is to implement a base class that extends the Activity class (or what ever base Activity used in your project) and let the base set the SlidingMenu. Then you would simple extend your base Activity in each of the Activities that are supposed to have a menu.
You could also do it the way you describe it, but then you would end up with a classic example of a God object (http://en.wikipedia.org/wiki/God_object). It's a neat way to practice your Fragment juggling skills and switching between Fragments instead of starting new Activities does have it's use cases, but I still wouldn't recommend it for a project with more then a few views.
Here is the answer that came closest to the issue I had - http://www.verious.com/article/polishing-the-sliding-app-menu/. Scroll down to the bottom of the page to see the last section titled "Using the fly-in app menu between Activities". This is one option if you have a lot of activities in your existing app and want to avoid extensive re-factoring. I haven't tried this out yet but its worth being aware of.
There are many implementations of facebook app-like sliding menu, which are mentioned in that question.
Some of them, which implementation I checked, are using one activity for showing menu and data. When user selects item from menu no new activity is start. Thus, one activity is using for many part of the program, showing different data in one view.
IMHO, it could be messy to use one activity for all. So, I'm thinking of new plan:
Add menu to all activities;
When user select item in menu, close(pop/hide) current activity and start (push/show) activity, which is related to selected item.
Any ideas to implement such behavior?
I'm way to lazy to read through all those answers in the mentioned thread and check all provided libraries.
A good sliding menu library which works properly with Fragments is SlidingMenu
Also you should take a look at the documentation on Activities, Intents (the flags you can set to them) and how their life cycles are managed cause you seem to mix up some things.
I am making my first android application with the ActionBarSherlock.
The application will always have an action bar consisting of 3 tabs (first tab selected by default).
The app could be extended for use with a tablet.
I have been searching the web, and following the android development guides, however I am finding a few things confusing.
The first tab screen will be a list view with a list of items, onitemselected should send the user to a screen which features more details about that item.
When should I use a fragment? Should each tab be a fragment?
Or, should each tab call a new activity, which consists of fragments?
And, if using fragments, should I place them in different classes, or embed them within an activity??
Appreciate any help, thanks.
you should probably read these two links first.
http://android-developers.blogspot.com/2011/09/preparing-for-handsets.html
http://android-developers.blogspot.com/2011/02/android-30-fragments-api.html
If you plan to make an app that work on both phone and tablet. It is a good idea to use a fragment, and then use a shell activity to wrap that fragment.
My experience with Fragments is mostly on ViewPager, so I am not entirely sure if it applies here.
In Android, you should use Fragments as much as possible. As a general rule of thumb, imagine you are translating the UI from phones to tablets, elements that can stay together in the same configuration should be a Fragment.
There is a Fragment subclass called ListFragment, so you might want to look into that for your first tab. (ListFragment is for Fragment like ListActivity is for Activity)
There is also a tutorial I found to deal with fragments. Did not really look into it but I hope it helps.
http://android.codeandmagic.org/2011/07/android-tabs-with-fragments/
As for ActionBar / ActionBarSherlock, I have absolutely no experience withit so someone might want to add to that.