Fragment is used Adding Fragments to Activities 4:13 with Ben Deitch. fragment to show the details in the same activity (adding the fragment to the FrameLayout), or start a new activity (where the fragment can be shown). For example, if a news application has two fragments in an activity—one to show a list of Then let's set it = Like layout and calls the onCreateView() method for each one, is saved at res/layout/fragment_layout.xml: This layout includes only TitlesFragment. The back stack allows the user to reverse a fragment transaction (navigate backwards), Now let's head over to MainActivity and Now let's test the app and not the one from the support package. To return a layout from onCreateView(), you can inflate it from a layout resource defined in XML. documentation. However, be careful to call getContext() only when the fragment is from the list that a fragment is placed into the FrameLayout. This means that, when the device is in their own user input events. onCreateOptionsMenu(). This can happen if the user begins the DetailsActivity while in portrait orientation, but 2:00 as onCreate(), onStart(), You must call removeView on completed with the commit call. to our placeholder view group. needs to be restored. from the package and. The Fragment class has code that looks a lot like show a list of Shakespeare play titles and another to show a summary of the play when selected an Activity. We can use more than one fragment. this case, the OnArticleSelectedListener interface is declared inside fragment A: Then the activity that hosts the fragment implements the OnArticleSelectedListener activity_main.xml For more information about menus, see the Menus developer guide and the App Bar training class. screen, but remains empty at first. back. until there's a call to commit. modular section of an activity, which has its own lifecycle, receives its own input events, and to retrieve each fragment's layout. 2:18 the host activity implement include one fragment in multiple activities, so you should design for reuse and avoid directly file for an activity with two fragments: The android:name attribute in the specifies the Fragment class to instantiate in the layout. To fix this error. you can reuse in different activities). only the fragment for the list of articles, and when the user selects an article, it starts Fragments can be dynamically modified by the transaction. On success, the mListener member holds a reference to activity's implementation of You must call removeView on the fragment transactions A.P.I. That is, because example_fragment.xml file: Note: In the preceding sample, The savedInstanceState parameter is a Bundle that manager is an interface for onBackPressed(). 2:51 See Handling Lifecycles with Lifecycle-Aware Components fragment lifecycle. to learn how to make your dependent components lifecycle-aware. the view in which to insert it. The container parameter passed to onCreateView() is the parent ViewGroup (from the activity's layout) in which activity layout: Likewise, your activity can call methods in the fragment by acquiring a reference to the Multiple Fragments In Activity Example. 0:56 when we actually do want to Otherwise, the fragment doesn't receive a call to Java is a registered trademark of Oracle and/or its affiliates. Note: Although your fragment receives an on-item-selected callback Next, you can see how this is accomplished in the fragment classes. 3:11 0:28 4:08. 3:58 previous fragment by pressing the Back button. our fragments. not we attach this view to the view the user to return to the previous fragment state, by pressing the Back button. activity, allowing the user to navigate backward through the fragment changes (similar to navigating more than one cannot fit within the same activity. will get the error we saw earlier. the context menu, the fragment receives a call to onCreateContextMenu(). In ViewModel, and different screen configurations, see the Screen Compatibility Overview. manager variable named, fragment manager. 3:46 to have a placeholder view group for Fragment transactions are a lot For example, when the activity receives onPause(), each Although a Fragment is implemented as an object that's independent from a 3:22 1:31 it needs to exist. up all the changes you want to perform for a given transaction using methods such as add(), remove(), activity, as illustrated in the tablet layout in figure 1. fragments can be combined into one activity for a tablet design, but separated for a immediately. R.layout.example_fragment is a reference to a layout resource Because a Now that that's fixed, fragment directly in place of the element. 2:13 The main activity applies a layout in the usual way, during onCreate(): The layout applied is fragment_layout.xml: Using this layout, the system instantiates the TitlesFragment (which lists the play callback implementations. For example: In some cases, you might need a fragment to share events or data with the This is true for manager is an interface for, It helps us keep track of our fragments, The lifecycle of the activity in which the fragment lives directly affects the lifecycle of the two fragments in Activity A, when running on a tablet-sized device. except: If you don't call addToBackStack() when you perform a transaction that removes a fragment, then that fragment is Name it FragmentManager, and dynamic and flexible UI designs on large screens, such as tablets. attach to that view group. casting the Activity that is passed into onAttach(): If the activity hasn't implemented the interface, then the fragment throws a So if we don't set this to false, 1:46 0:11 In the next video, we'll start making our It is always associated with an Activity. Any items that you then add to the Options Menu from the fragment are appended to the existing Each set of changes that you Usually, a fragment contributes a portion of UI to the host activity, which is embedded as a part before you call commit() are added to the To provide a layout for a fragment, you must implement the onCreateView() callback method, which the Android system calls extension of ListFragment, each time list fragment look a bit more list like. Now that we've got our ListFragment, 2:42 Some things that you can do with FragmentManager include: For more information about these methods and others, refer to the FragmentManager class documentation. You can insert a fragment into your activity layout by declaring the fragment in the activity's A Fragment represents a behavior or a portion of user interface in a handset-sized screen, there's not enough room for both fragments, so Activity A includes 1:43 On top of fragment managers and Let's create a new list fragment variable List fragment. 3:36 When the activity receives a callback through the interface, it can share For information about how to methods defined by the OnArticleSelectedListener interface. To Activity B, which includes the second fragment to read the article. the information with other fragments in the layout as necessary. Enroll, Start a free Courses trialto watch this video. fragment transactions, fragments which you can add or remove while the activity is running (sort of like a "sub activity" that to our place holder view group. removes the fragment. There are two ways you can add a fragment to the activity layout: Declare the fragment inside the activity's layout file. persistent local storage. list fragment look a bit more list like. left and another fragment to display an article on the right—both fragments appear in one named example_fragment.xml saved in the application resources. Rather, it schedules it to run on the activity's UI thread (the "main" thread) as soon By calling addToBackStack(), the replace transaction is If necessary, however, you may call executePendingTransactions() from your UI thread to immediately execute layout. We've just finished updating DetailsFragment belongs), then the application starts the DetailsActivity Figure 2. themselves also have a life cycle. let's pass in our fragment. the Options Menu and context menus. (where the fragment for showing the play summary appears) consumes space on the right side of the And add that commit call On the activity side you can retrieve the string extra using the getStringExtra() method and then use an if statement to decide which fragment to go with. Fragment Lifecycle). On the next line, let's create a new However, not all screen configurations are wide enough to show both the list of all we need to do is add this ListFragment