Is it possible to build up an architecture like this with fragments:
Navigation drawer showing the main menu and then when clicking one of the menu items an ordinary combo of list/detail is shown (so far so good, all tutorials explain this). But what if I want a button on the detailed fragment to show a second combo of list/detail fragments, which should not be reached through the Navigation Drawer?
As I have implemented it now, one fragment instatiates the next, which is wrong according to the guides (fragments should always communicate through an activity). But it works fine as long as the user is clicking deeper into the app. The issue comes when he starts to use navigate back, because all the UIs then start to be laid on top of each other.
I wouldn't. Fragments aren't 100 percent consistent across all versions of Android, unless you're using the support library. Even then- nested fragments have always been a bit broken. They weren't even supported at first. The more levels of nesting you add, the less likely it is to work as expected. I wouldn't add more than 2 levels of fragments, and I'd try hard to keep it to 0-1.
Related
I am coming from iOS and working to port an iOS app on android. In iOS there is the storyboard where you can connect different view (activities) and embed them into tab bars and navigation bars. I am having an issue to understand what is the best way to implement bottom navigation in android...
Let say I have 3 bottom navigation items with the following
tab1
page1.1
page1.2
tab2
page2.1
page2.2
page2.3
tab3
page3.1
page3.2
page3.3
As an example in tab1 I have page1.1. Then let say I have a button in page1.1 which bring me in page1.2. If I go back from page1.2 I want to go back to page1.1. Same story for page2.1, I can go to page 2.2 and from page2.2 I can go to page2.3. I also want to go from page3.2 to page 1.2
I have read fragments are the best way to do it (each page.x is to become a different fragment with a different layout) but it does not seem very easy. I have also read I can use activities but many suggest not to use it
What do you recommend that I focus on? Are there any other solution to consider on top of fragment and activities? Thanks
You should use Fragments with a Single Activity. If you don't, you will have to copy/include one bottom bar in multiple Activities. It might be useful in some cases however when Activity is switched, your bar will redraw which might turn out to be a bad user experience.
I have read fragments are the best way to do it (each page.x is to become a different fragment with a different layout) but it does not seem very easy
Using Fragments might actually make it easier than if you use Activities. If you use Fragments, you can have one Activity be in control of every fragment that is being displayed, meaning that you can control navigation based on which fragment is being shown. This way, you can handle some special scenarios that do not fall into usual navigation behavior.
Doing the same in Activities would be a little more difficult since you'd have to continuously pass around data in Intents and it would be difficult to control the behavior since your logic will be spread across Activities.
What do you recommend that I focus on? Are there any other solution to consider on top of fragment and activities?
These two are only recommended solutions. If some of your UI elements are same in all pages while some part of it is changed constantly, then its best to use Fragments with single Activity. For screens that are completely different or that are not part of your navigation flow, you add more Activities for them instead of Fragments.
For example, You can use Fragments in One Activity with Bottom Navigation Bar, but for settings screen or profile screen, you should make separate Activites.
I've recently been looking into the navigation system that Android uses with as intention to port my iOS app that uses an UITabBarController containing multiple UINavigationControllers. To replace the tab bar (which is not available on Android) I settled on using the built in DrawerLayout.
From what I've read, navigation in Android is generally done by creating an Intent, providing it with extras and then just replacing the current activity. This automatically makes sure the back button works, and optionally the back button in the top left if enabled.
However, I am not sure how to implement this way of navigation with the navigation drawer. The tutorial tells me to create a DrawerLayout containing a FrameLayout and a ListLayout where the FrameLayout will contain the actual application and the ListLayout will contain the navigation. This would mean that when I use the method described above to "navigate", it would replace the activity and thus removing the drawer.
What would be the best way to implement what I want (basic navigation with back button support while maintaining a global drawer navigation menu)? The possible options I can come up with is always keeping the same activity and dynamically replacing the FrameLayout, but that would mean a lot of boilerplate to render and possibly a hack to support the back button (and there would be no animations :(). The other option would be to just render the drawer on every activity (via subclassing or something), but that would mean that if the user navigates a lot the back button "stack" would become quite large.
I have tried to explain what I need in as much detail as possible, but it is quite hard to explain the concept. Basically, I want something similar to the UINavigationControllers in the UITabBarController.
You can either have one Activity with one NavigationDrawer and present the user with different views by switching Fragments back and forth within that one Activity. You would use the FragmentManager to switch between different Fragments.
Or you can use multiple Activities that all have a NavigationDrawer.
Second option might sound more difficult but it really isn't. You create a base Activity that all your Activities inherit from and all let them have their own NavigationDrawer, no problem.
Sure there's something in between or something completely different, but that's the most straightforward approaches I can think of.
The tutorial you've probably used (the one with the planets) is imho a bit misleading because it assumes a very basic app structure. If you have only little different 'screens' that might work, for a very complex application it's not suitable (again, in my opinion).
I've always opted for the second option because handling the navigation / backstack is just easier with Activities / Intents.
There's loads of different flags that you can set to your Intent to influence their navigation behaviour.
Also see this and that documentation. These documents might have been written when the NavigationDrawer pattern was not all that common but they are still useful.
This is a bit of a desperation call for some good advice.
I began doing a project which involves Navigation drawer as the main menu for the application. After looking at the Android tutorial I followed the example and start developing on top of that. That example is a single activity that replaces the fragments depending on the selected option in the drawer. In part, I followed this design because if I launched Activities the drawer was lost and the Activity would appear with the launching transition and didn't look nice at all.
Now, my project is not a small one. During development I faced several issues like:
onResume not being called on the Fragments (due to not being attached to several activities but one instead.
All the data between Fragments should pass through the single Activity
Managing the Options Menus in the ActionBar became a real pain.
And many others I don't recall now
Now I am facing a new issue. In one of the fragments I need to have a Spinner that will switch fragments inside this one. And of course, the fragment will need to change the navigation mode in the action bar. This was a major headache to develop, but now I am facing a bigger problem with some fragments inside losing the activity context (like if they were detached).
After so many problems I just decided to switch back the whole app to Activities (this is a custom app that will run in just 1 tablet model, so no worries about fragmentation). So, in short I am looking for advice on the less painful way to do this.
I am on a extremely tight deadline that lead me to start implementing without designing (like a complete noob). Now I am being hit with so many issues that, if I didn't need the money, I would cancel this project at once.
Please help!
I can give a little advice, but sadly your situation can't really be solved by any one answer here.
First off, switching from a Fragment design to an Activity design is a lot easier than switching the opposite way. You can actually use all of the fragments you had before, and just have each activity loading only 1 of the fragments (or multiple if you prefer).
Also, when handling Intents (starting new activity), after the startActivity() call you can call overridePendingTransition() to make the launching transition whatever you want (or remove it completely).
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.
I'm looking for the the best way to reproduce, in an Android app, the behavior of the iPhone UiNavigationController within an UITabBarController.
I'm working on this Android app where I have a TabActivity and 4 tabs. I've already gone through a lot of posts regarding the use of activities and tabs and how it's not a good idea to use activities for everything, which seems fair enough. I decided to use one Activity on each tab anyway, since it makes sense in my application.
However, in one of those activities I have a deep navigation tree with more than one branch and up to 12 different views the user can go through.
The problem is: Android controls the navigation through activities inside an app, if you click the back button it will go to the previous one, but if I'm navigating through views, using one Activity, and I click back, it just finishes it. So how can I have a smooth navigation behavior between views in an Activity?
I had implemented this using a TabActivity with FragmentActivity as each tab. Utilizing Fragments API you can organize the code just like you would be using 12 different activities, still using only 1 for each tab in fact. Fragment's framework will handle back key press for you to show previous fragment instead of closing the entire activity.
There are some problems with such approach, for example, there's no MapFragment, but the workarounds can be found here on SOF.
You will need Android Support Package if your minimum SDK version is lower than 3.0.
Well I know very little about UiNavigationViewController, but I guess you want something to navigate between different Views. As you are using TabActivity, every tab should load into a separate Activity.
But since you want to branch it out, using that many Activities is not a perfect solution, neither the ActivityGroup too. The better solution, as per my opinion(I have run into similar problem once) is to have the main or root tabs loads into separate Activity, but for their branches, use the ViewFlipper, which flips the Views. So the whole Layout(Subclass of View) can be flipped.
You may run into some problem while flipping more than two Views (as what people say, though I never had any problem). So in that case you can use layout.setVisibility(View.GONE) to hide the layout and just change it with View.VISIBLE for next view.
And about the concerns of back button, you need to store the last used View or Activity into a variable, and in the override of onBackPressed(), just need to call them.
There might be better solution than this, not that I can remember, but yeah it's the easiest solution I can come up with.