Using Fragments to switch activities - android

I'm trying to create a layout that has a stationary footer with activities that slide behind it. I've been told to use Fragments, but that would mean that I would have to convert my already existing Activities to Fragments - right? Here is a diagram of what I'm trying to achieve: http://i.imgur.com/K8Iao.jpg

What I think #TarunMaheshwari is trying to say is that instead of having 3 activities (eg. classes with extends activity), replace it with extends fragment (obviously there are other minor changes you might have to make for the code to work) and then create a main activity (with extends FragmentActivity) that has the static footer you want which can call on the 3 different fragments.
Recommended readings:
http://developer.android.com/guide/topics/fundamentals/fragments.html
http://android-developers.blogspot.ca/2011/02/android-30-fragments-api.html

I believe using fragments is the right solution for your app. However, from what I understand from your question and comments, you really want to avoid using them. To use activities instead of fragments, implement a Tab Layout with a Tab Host and Tab Widget as explained in this tutorial. This solution allows you to use the tabs to switch between activities.
To align the Tab Host to the bottom of the screen, have a look at this tutorial.

Related

Upgrade/Migrate from Multiple Activity Intents to Single ViewPager & Fragments

I used to have 3 activities with 3 layouts.
1. HomeActivity.java (activity_home.xml)
2. HelpActivity.java (activity_help.xml)
3. SettingsActivity.java (activity_settings.xml)
Whenever i had to open other activities, i used animated slide-in-out intents using overridePendingIntent. In this way, all the variables of HomeActivity stayed in itself and HelpActivity's variables/methods were in itself and same for SettingsActivity. I used onCreate() in these to perform some activity specific code. and, android:onClick="fetchSarcasm" from activity_home.xml was calling specified method in HomeActivity.java. So, there were no conflicts. All the normal things, that happen in an AndroidProject with 3 activities and used intents to switch to one another, were happening as i wanted.
But now, I wanted to migrate to ViewPager instead of slide-in-out intent transitions. In this way, there will be only one Activity with an XML of ViewPager. This ViewPager and its FragmentPagerAdapter gets the Pages from 3 classes extending Fragment with relative XML layouts.
I want to ask: Where do i write my Page Specific Code for onCreate(), layoutView's onClick="" and for onChangeListeners. Because, 3 classes extending Fragment do not have any Context or findViewById() and they do not respond to android:onClick="method" in different layouts.
Do i need to mix all that code of three activities into one containing ViewPager? If so, this makes ViewPager activity pretty heavy. and, writing if(page=2){ dothis(); } seems absurd for all pages at every code point. Any checkbox(view) that is in page 3, becomes null in other pages.
I know this might be a stupid question. I have spent almost 4 days trying to achieve something but i can't. Also, this is just my 2nd month in android, so i am new. I do not use Action Bars, Tabbed Bars or Navigation Drawers.
I am available on SO Chat too if you want to ask something more.
I just want to know how do i merge all the work i did when I was not using ViewPager.
If you're only reading the Preferences once for each Fragment, you can move your previous Activity.onCreate() logic to each Fragments onViewCreated() or onCreateView(). Read your shared Preferences there and set your Checkboxes accordingly.
Fragments inside a ViewPager aren't necessarily recreated on each page change. You can change how many Fragments are instantiated at a time with ViewPager.setOffscreenPageLimit(int).
Fragment Lifecycles explained

Activity or Fragment with NavigationDrawer

I have 4 modules in an application that are not related to each other. So I previously had created 4 different activities all extending to a base activity that implements the NavigationDrawer. I would like to know if it is better to use fragments over here instead of activity?. I mean, if I make one activity that implements the NavigationDrawer and create 4 fragments for the 4 modules?. Also, what is the difference between Fragment and FragementActivity?
I think one activity that implements the NavigationDrawer and creates 4 fragments for the 4 modules. It's better!
Activities are designed to represent a single screen of the application, while Fragments are designed to be reusable UI layouts with logic embedded inside of them. According to Google's lectures :Multi-Versioning Android User Interfaces . Fragments makes your code easier to maintain and control.
what is the difference between Fragment and FragementActivity?
You can see here: Difference between Fragment And FragmentActivity

How to select the activity and the fragment

What scenarios using fragments what scenario using the activity , How can I make sure you when to use the activity when using fragments !
Basically, when you want a fixed portion of the screen and the rest will be changing, you want to use fragments.
If all your app is going to be on different screens, you want to use Activities.
Anyway, at least you will need one activity to hold your fragments.
Hope this helps.
As i know,You need to extend the fragment when you are displaying the view into tabs.
Otherwise you can extend activity.
It depends on your requirement. if u want to expose your toolbar throughout your application you can use fragment both activity and fragment are quite similar . You can also use only one activity remaining things may be your fragment
It depends on UI which you are creating.
If you are creating Multi-Pane UI then you should use Fragment.
And if you are creating some part of screen which can be reused then for that part you should create Fragment as Fragment is meant for re-usability.
If you are creating stand-alone screen then you should use Activity
For more info please refer this link How to choose Activity or Fragment if both scenarios are possible?

Best way to add tabs within android app

I'm thinking of adding tabs to my android app. Currently, I am using the same activity and adding the appropriate fragments based on the tabs selected. I was wondering if that's a good way, or should I add an activity per tab and then within the individual activity, have fragments as needed?
I think you are on right track. Have one Fragment Activity and attach all the fragments to that activity.

Anyone have example code using switched Views instead of Activities inside a TabHost on Android?

The Android developer guide (http://developer.android.com/resources/tutorials/views/hello-tabwidget.html) states:
`You can implement your tab content in one of two ways: use the tabs to swap Views within the same Activity, or use the tabs to change between entirely separate activities. Which method you want for your application will depend on your demands, but if each tab provides a distinct user activity, then it probably makes sense to use a separate Activity for each tab, so that you can better manage the application in discrete groups, rather than one massive application and layout.
In this tutorial, you'll create a tabbed UI that uses a separate Activity for each tab.`
In my cases, it doesn't make sense to have separate activities for the tabs so I want to switch views, but it would be nice to see an example.
Gee, thanks Google!
In my cases, it doesn't make sense to have separate activities for the tabs
I have yet to find a good argument for having separate activities for the tabs.
so I want to switch views, but it would be nice to see an example.
Here is one. Here is another.
The recipe is pretty simple:
Step #1: Add the tab contents as child Views of the FrameLayout
Step #2: Use the setContent() (on TabHost.TabSpec) that takes an ID as a parameter
Step #3: There is no step #3

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