Android Single Instance Fragment

That's where fragments come in. A Fragment is a self-contained component with its own UI and lifecycle; it can be-reused in different parts of an application’s user interface depending on the desired UI flow for a particular device or screen. Activity can have multiple fragments attached to it. But how can I get that fragment. That’s where fragments come in. Before starting this tutorial just go through Fragments Tutorial if you. The tutorials here emphasize proper code design and project maintainability. Now create a new instance of this Fragment in MainActivity, and then add it to MainActivity's layout by. To do this, your view hierarchy must contain a ListView object with the id "@android:id/list" (or list if it's in code). Android spinner is like the drop down menu with multiple values from which the end user can select only one value. The requested URL index. In the example on using fragments in the Android docs, when the application is in 'dualview' mode, the details fragment is recreated whenever the application needs to show details for a different title. addToBackStack(null); we only add a single instance to the BackStack? Adding multiple instances of the same fragment to the Back Stack creates a clutter when the. The same instance is used across the application whenever it’s retrieved. Android has a major limitation: you can only display a single Activity onscreen at any one time. In this tutorial, you will learn how to implement a DialogFragment in your Android application. Specialized Fragment Classes. The DialogFragment is a Fragment that is used to display a dialog object inside of a Fragment that will float on top of the Activity's window. Fragments Part of Android Jetpack. TitlesFragment):. CalendarAlerts. This single screenshot shows why iOS is years behind Android in usability. Activities — single activity. They observed that banning single-use plastic products had its benefits. ClickableSpan ↳ android. Every Fragment in the Navigation Stack must extend NavigationFragment in order to properly be displayed and navigated. AuthStateListener() works correctly and returns null as FirebaseUser instance in onAuthStateChanged, I refresh UI and show "Sign in with Google. In Android, a Fragment represents a modular piece of a larger UI. FragmentTransaction. Multi-Instance Sync. package android. Singleton). This can only be used with fragments not in the back stack. Patrick Stewart returns to. Creating Fragments. is used as a container for FragmentsCode for Fragment Switching:. Spinner Tutorial With Examples In Android Studio. Intents are only usable for sending data on an Activity level. Declares an activity (an Activity subclass) that implements part of the application's visual user interface. a different Android Fragment or page. One of my favorite navigation pattern implementations is based on the "One-Activity-Multiple. Following are important points about fragment − * A fragment has its own layout and its own behaviour with its own life cycle callbacks. The main problems of Activity: The stack management of Activity is weak, Intent and LaunchMode are confusing, even if. Fragment Lifecycle In Android: In Android, Fragments have their own life cycle very similar to an Activity but it has extra events that are particular to the Fragment’s view hierarchy, state and attachment to its activity. Recent Dagger version 2. In this first part, I provide information about the use of onSaveInstanceState( ) and onRestoreInstanceState( ) methods of the activity for saving and restoring state. Android One phones will receive at least two years of OS upgrades. Originally, HTML was primarily designed as a language for semantically describing scientific documents. But how can I get that fragment. 1 Mobile App Development Tutorial How To Manage Multiple Fragments On Single Activity. In a Fragment, there are UI view objects and instance variables. addToBackStack(null); we only add a single instance to the BackStack? Adding multiple instances of the same fragment to the Back Stack creates a clutter when the. To bias autocomplete results to a specific geographic region, call setLocationBias() on your app's AutocompleteFragment instance, or IntentBuilder instance, passing a RectangularBounds. Communication start from the fragment to the activity and then from the activity back to the fragment or to another fragment if you have more than one fragment displayed. All activities must be represented by {@code } elements in the manifest file. How To Save / Retrieve Fragment Instance Data. Androids materialistic designs uses Fragments instead of Activities. 4 Audience. The user interface for the first fragment will contain a toolbar of sorts consisting of an EditText view, a SeekBar and a Button, all contained within a RelativeLayout view. Otherwise we get a warning that says “Avoid non-default constructors in fragments: use a default constructor plus Fragment setArguments(Bundle) instead” or. Also like an Activity, a Fragment receives its own input events. You need to read one bite per iteration, analyze it and then write to another file or to sys. Second, let's take a look at how to build a dialog simply by customizing the available Dialog objects that we can construct. FragmentPagerAdapter calls detach(Fragment) on the transaction instead of remove(Fragment). Each fragment has its own lifecycle, and is not affected by the lifecycle of the other one. Ask Question I defined the fragments as Singletons in the FragmentA extends Fragment class: private static instance = null. It contains three. You create fragments by extending Fragment class and You can insert a fragment into your activity layout by declaring the fragment in the activity's layout file, as a element. Come to the definition, You can use multiple fragments in a activity and same fragment in multiple Activity in the Android application. Android Instant app is an update to your existing Android app which makes it feasible for individuals to access a broader array of apps. https://tidalgaming. The main problems of Activity: The stack management of Activity is weak, Intent and LaunchMode are confusing, even if. Any fragments being initialized in an Activity need to be looked up by tag after a configuration change:. To retrieve an instance of SharedPreferences that the preference hierarchy in this fragment will use by default, call PreferenceManager. The thing is the only examples I've seen online of starting a fragment from an activity was when RecyclerViews were being used. Several solutions for this single instance problem have been posted, but usually do not include running in Linux. While a single Fragment can be shared by different activities, each specific instance of the Fragment is exclusively tied to the Activity that hosts it. This Java code shows how to implement a couple of things in an onCreateView method inside a Fragment class: Android: An example onCreateView method in a Fragment class | alvinalexander. Silence A collec. Specialized Fragment Classes. If the Fragment instance exists on the stack, then all the other Fragment instances on the top of the stack are cleared and the Fragment instance is placed on the top and displayed. Join my social networking android application development course on udemy Udemy Free Course coupon link https://www. a different Android Fragment or page. Portions of this page are modifications based on work created and shared by the Android Open Source Project and used according to terms described in the Creative Commons 2. 1 Mobile App Development Tutorial How To Manage Multiple Fragments On Single Activity. For instance we did not do any experiments with Apple Watch or with the Samsung or Android telephones or any third-party app. Android Activity Launch Mode can be opted from any four modes as described below. The Fragments Walkthrough - Part 1 demonstrated how to create and use fragments in an Android app that targets the smaller screens on a phone. This causes return from map fragment to list fragment when in single-pane mode. All events and the position of the pointers are included in the instance of MotionEvent com. Because the code like below is too ugly:. Fragment是Android honeycomb 3. Mapbox's demo app on the Google Play Store includes many examples of how to use the Mapbox Maps SDK for Android. Like an activity, a fragment has a lifecycle with events that occur when the fragment's status changes. Fragment; android. Details of how this is supposed to be done can …. Square in their phenomenal article Advocating Against Android Fragments, pointed out the following key problems with fragments: overly complicated life-cycle, asynchronous fragment transaction, and the confusion between using fragments vs. It will return an Android View object that is the fragment. This diagram shows where plastics end up throughout their long. */ public interface FragmentTransaction { * Calls {@link #add(int, Fragment, String)} with a 0 containerViewId. A fragment life cycle is closely related to the lifecycle of its host activity which means when the activity is in the pause state, all the fragments available in the activity will also stop. With Android fragment transaction we mean a sequence of steps to add. This single screenshot shows why iOS is years behind Android in usability. Android application is using. seqpos( intra_frame_pos ) for dofs that are allowed to move in the MoveMap More virtual bool apply_ss (std::string &, Size intra_frame_pos, Frame const &) const insert fragment_data sec-struct into ss-string at position seq_pos More virtual bool. Fragments were added to the Android API in Honeycomb version of Android which API version 11. This guide explains how to implement a swipeable UI with ViewPager, using Fragments as the data pages. fragment_left. To put it simply : Use fragment when you have to change the UI components of application to significantly improve app response time. If you're supporting older android versions, you can make use of fragment-compatibility support library. A Fragment is a self-contained component with its own UI and lifecycle; it can be-reused in different parts of an application's user interface depending on the desired UI flow for a particular device or screen. The Fragments Walkthrough - Part 1 demonstrated how to create and use fragments in an Android app that targets the smaller screens on a phone. ジレンマ:いつフラグメント対アクティビティを使うべきか: ViewPagerでフラグメントがいつ表示されるかを判断する方法. HTML is the World Wide Web's core markup language. An Introduction to the ViewPager. Since the Android system uses the default no-arg constructor when recreating a fragment, we should not pass values over an overloaded constructor with arguments when we instantiate it. app namespace. One thing i don't wanna do is to create a private instance of Fragment A in Activity and call it's method. : Fragment « Core Class « Android. It is like window or frame of Java. This enables either having all release packages share the same SigningConfig, by setting android. With this tool, you can organize your inbox in a way that you don’t lose important emails. Devices can be remotely provisioned with the required app (single app Kiosk) or a set of apps (multi-app Kiosk) and with advanced. Silence A collec. You may also use Android toolbar to switch between fragments. Get current fragment displayed in ViewPager on Android. Second, let's take a look at how to build a dialog simply by customizing the available Dialog objects that we can construct. At CES 2020, the tech industry's biggest event of the year, thousands of cutting-edge products and services were unveiled. https://tidalgaming. You can combine multiple fragments in a single activity to build a multi-pane UI and reuse a fragment. Since the ViewModel doesn't know. This is a common navigation mode to use instead of ActionBar Tabs with Fragments. This booking photo obtained April 26, 2018 courtesy of the Sacramento County Sheriff’s Office shows suspect Joseph James DeAngelo. Specialized Fragment Classes. Creating the FullScreenDialog class. There can be many scenarios where communication between fragment is required. California authorities, after a 40-year manhunt, on April 25, 2018 announced the arrest of a 72-year-old former police officer on suspicion of being the notorious “Golden State Killer,” a serial rapist and murderer who terrorized the state in the 1970s and 1980s. Developers can combine one or more fragments to build a single activity or even reuse fragments across multiple activities. MOST Web Documentation, Release 1. Spinner Tutorial With Examples In Android Studio. Each fragment has its own lifecycle, and is not affected by the lifecycle of the other one. Multi-Instance. Next we need to create the FullScreenDialog class by extending the android-support-v4 DialogFragment. Fragment A and Fragment B are the same on both form factors, but the Activities that host them are different. This post describes how to use Android Fragment transaction to handle fragments. Android: the Single Activity, Multiple Fragments pattern | One Activity to rule them all 1. The application created in this chapter will consist of a single activity and two fragments. a different Android Fragment or page. This fragment contains a Dialog object,. 0 introduce the Fragment, Fragment is a portable user interface that makes possible in multi-pance UI creation, it is working like a View and you can add many Fragments to a single Activity. Fragment Transactions & Activity State Loss | Android Design Patterns. Developers can combine one or more fragments to build a single activity or even reuse fragments across multiple activities. There are two ways to add a fragment to an activity: dynamically using Java and statically using XML. However, a given instance of a fragment is tied to the activity that contains it. of PreferenceFragment, showing a single. The Fragment class uses callback methods that are similar to Activity callbacks, such as onCreateView() , which provides a LayoutInflater object to inflate the. : Fragment « Core Class « Android. で, いまどきのストラクチャーでどのような構成にするのか. 0 further helps applications adjust their interfaces with a new class called Fragment. You can combine multiple fragments in a single activity to build a multi-pane UI and reuse a fragment in multiple activities. The tutorials here emphasize proper code design and project maintainability. Below are the methods of fragment lifecycle. Before embedding a "support" fragment in an Activity make sure the Activity is changed to extend from FragmentActivity or AppCompatActivity which adds support for the fragment manager to all Android versions. A fragment life cycle is closely related to the lifecycle of its host activity which means when the activity is in the pause state, all the fragments available in the activity will also stop. Fragments Part of Android Jetpack. Fluctuations 02. I have to call a method of Fragment A after getting result from Fragment B. This results in using only a small amount of Memory and can be useful for handling larger data sets. FLAG_SINGLE_INSTANCE: 若栈中存在该Fragment实例, 则将该Fragment实例置顶并显示. Note that there are limits on how this can be used: The Fragment must currently be attached to the FragmentManager. For this to work properly make sure that all the fragment related items (FragmentDialog) are from the android. You do not need to. There are two ways to get current visible fragment page in ViewPager. This is the second post of a two part series of posts dealing with saving and retrieving Android instance state. Start a new Basic Activity project and accept all the defaults. Its can be said to be a sub-activity. However, a fragment is placed into a back stack managed by the host activity only when you explicitly request that the instance be saved by calling addToBackStack() during a transaction that removes the fragment. Often we need to lookup or find a fragment instance within an activity layout file. In the above, each unique stack associated with a different FragmentManager can be manipulated without affecting the others, despite sharing the same FragmentManager, provided Fragments are only added on top of the stack. The Android system can hold multiple tasks at the same time and only one task is in the foreground. The NewInstance method will take a single parameter – the index of the quote to display. Used to set single selected item. Corporate email management is crucial to an organization's productivity and security. This makes it easier to conditionally include the HAL module in the build system. A fragment is implemented as independent object -- independent of the activity that contains it. An Activity with singleTask launchMode is allowed to have only one instance in the system (a. Most of the popular apps like Instagram, Youtube, Spotify etc. A Fragment is a piece of an activity which enable more modular activity design. Every Fragment in the Navigation Stack must extend NavigationFragment in order to properly be displayed and navigated. An Android fragment is a GUI component which can "live" inside an Activity. Let’s see how we do multi-pane development in Android using fragments. i want to learn what must i do, when click a product list item what must be my way. In this first part, I provide information about the use of onSaveInstanceState( ) and onRestoreInstanceState( ) methods of the activity for saving and restoring state. Maintenant, je dois passer le résultat de Fragment A. Also, it gives a thorough. In Android, Fragment is a part of an activity which enable more modular activity design. By default, Fragments are destroyed and recreated along with their parent Activitys when a configuration change occurs. Bottom navigation provide easy navigation for switching between 3 to 5 different views. This page will walk through the android FragmentManager and FragmentTransaction example in which we will replace Fragment with another Fragment using Button OnClickListener. Otherwise, new Activity would be created and placed in the. When it comes to home screen flexibility, the iPhone is even less flexible than the Palm handhelds were back in the 1990s. 0, the recommended means of retaining active objects across Activity instances is to wrap and manage them inside of a retained “worker” Fragment. Tab Layout with Different Fragments - Android Studio Tutorial instead of providing a different instance of the same Fragment all the time. It is meant to replace the managed dialog APIs (starting in Android 3. Single Activity can use multiple fragments and fragment usable in several activities. Android Fragments : adding fragment to placeholder task. com/social-networking-android-app-d. You can combine multiple fragments in a single activity to build a multi-pane UI. Typically you get in this method a reference to the activity which uses the fragment for further initialization work. You can achieve this association by defining each fragment within your activity layout XML file. This post describes how to use Android Fragment transaction to handle fragments. je ne suis pas en mesure d'obtenir l'instance de Fragment A. // are added to the back stack as a single transaction and the Back button // A given instance of a fragment is directly tied to the. It was recently added to the Material Design spec, which provides an alternative between tabs and navigation drawers. Before changing to Android Navigation, it was an Activity that instantiates this viewModel and all the other Fragments that belongs to this flow uses a shared instance of this viewModel, now that I've changed to Android Navigation and my only activity is the Main activity, I want to start a fresh instance of the viewModel for every time that I. 0 further helps applications adjust their interfaces with a new class called Fragment. You need to read one bite per iteration, analyze it and then write to another file or to sys. If there is an existed Activity instance in the system, the whole Task hold the instance would be moved to top while Intent would be delivered through onNewIntent() method. This fragment does not use a layout file to create a view. SQLite is a lightweight transactional database engine that occupies a small amount of disk storage and memory, so it's a perfect choice for creating databases on many mobile operating systems such as Android, iOS. The Android system can hold multiple tasks at the same time and only one task is in the foreground. Just change the android:text=”Tab tab_number”,for every layout file to see the tabs are switching or not. Android: the Single Activity, Multiple Fragments pattern | One Activi…. This can be used later when creating a new instance of the Fragment and adding it to the fragment manager, to have it create itself to match the current state returned here. For instance, we often work with marketing departments on projects that create positive byproducts for product teams, and vice versa. All events and the position of the pointers are included in the instance of MotionEvent com. The tutorials here emphasize proper code design and project maintainability. Start a new Basic Activity project and accept all the defaults. CalendarAlerts. Here is a look at fragments and how to use them in your Android apps. Android Spinner Example. An application that uses Fragments must, therefore, make use of the android-support-v4 Android Support Library in order to be compatible with older Android versions. android:tag can be used in to provide a specific tag name for the fragment. * @return A new instance of fragment BlankFragment. For the fragment state to be saved properly, we need to be sure that we aren't unnecessarily recreating the fragment on configuration changes. com alvin alexander. It is meant to replace the managed dialog APIs (starting in Android 3. Button class on Android; there is no web runtime involved in React Native. In this tutorial, you will learn how to implement a DialogFragment in your Android application. To retrieve an instance of SharedPreferences that the preference hierarchy in this fragment will use by default, call PreferenceManager. You can use multiple fragments in a single activity to build a multi-pane UI and can reuse a fragment in multiple activities. Fragments In Android Applications; Introduction In this article, you will see how to add a fragment dynamically at run time. Fragments Part of Android Jetpack. Fragments are for reusable ui or representing things in a different way on tablet vs mobile. In the above, each unique stack associated with a different FragmentManager can be manipulated without affecting the others, despite sharing the same FragmentManager, provided Fragments are only added on top of the stack. Android Fragments. This means that the Application and all Activities, Fragments, and child Fragments and their dependencies will share the same single instance of this class. Each fragment instance exists within a single activity; therefore, this fragment must cooperate in some way with the activity life cycle. The Samsung Galaxy Watch is arguably superior to the Apple Watch. The DialogFragment has the same lifecycle and callback methods as any other Fragment. Used to set single selected item. About the Example Fragment Application. You can achieve this association by defining each fragment within your activity layout XML file. * You can add or remove fragments in an activity while the activity is running. In this post, …. A Fragment is a self-contained component with its own UI and lifecycle; it can be-reused in different parts of an application’s user interface depending on the desired UI flow for a particular device or screen. The DialogFragment is a Fragment that is used to display a dialog object inside of a Fragment that will float on top of the Activity's window. Lecture 9 - Fragments and ActonBars. The fragment and the activity is not fully initialized. In your Android. Android spinner is like the drop down menu with multiple values from which the end user can select only one value. To create a dialog you simply created an instance of the Dialog class and call its show method to make the dialog window appear. A Fragment might be used to present a sliding drawer, tabbed content, a page in a ViewPager, or it might simply represent a normal screen in a single- Activity app. The Android system can hold multiple tasks at the same time and only one task is in the foreground. Shared preferences is a built-in key-value storage. Mapbox's demo app on the Google Play Store includes many examples of how to use the Mapbox Maps SDK for Android. Android provides a few different options for retaining application data. Multiple Fragment Stacks with a StackNavigator powered by a single FragmentManager. You do not want to attach it twice. Start a new Basic Activity project and accept all the defaults. For this to work properly make sure that all the fragment related items (FragmentDialog) are from the android. These can be any support fragments you define within your application. Its general design, however, has enabled it to be adapted, over the subsequent years, to describe a number of other types of documents and even applications. Fragments Part of Android Jetpack. A Fragment is a piece of an activity which enable more modular activity design. a Fragment, a Service, the Application itself and even the underlying process. Things to consider when dealing with SQLite:. a new method to get your ViewPager Fragments instance. (Issue #1 wasApril 1994, the month Linux hit version 1. A New Vulnerability in the Android Framework: Fragment Injection. This can only be used with fragments not in the back. Android Jetpack Architecture Components: Getting Started. The Master/Detail flow is part of android design pattern which uses the screen size or orientation of a device to decide how a given data should be layout. 5 Attribution License. To create a dialog you simply created an instance of the Dialog class and call its show method to make the dialog window appear. Fragment Transactions & Activity State Loss | Android Design Patterns. For this to work properly make sure that all the fragment related items (FragmentDialog) are from the android. Because a tablet's screen is much larger than that of a handset, there's more room to combine and interchange UI components. For instance we did not do any experiments with Apple Watch or with the Samsung or Android telephones or any third-party app. Fragment Transactions & Activity State Loss | Android Design Patterns. putString("greeting", "Hello");. Gfycat Core SDK. The Samsung Galaxy Watch is arguably superior to the Apple Watch. The user interface won’t be rendered in a browser’s DOM but using the native user interface libraries on Android and iOS. Samsung is most likely the greatest and most prosperous company in producing Android devices. The only thing that I’ll be doing here is include a TextView. It also handles persisting values to the device. FragmentSwapper is an Open Source Android library that allows easy fragment's management. Androids materialistic designs uses Fragments instead of Activities. Android default Database engine is Lite. To put it simply : Use fragment when you have to change the UI components of application to significantly improve app response time. By continuing to use Pastebin, you agree to our use of cookies as described in the Cookies Policy. This is called after onPause(), this is where you will store the data that you want to keep when the user come back to this fragment. Fragment Lifecycle In Android: In Android, Fragments have their own life cycle very similar to an Activity but it has extra events that are particular to the Fragment’s view hierarchy, state and attachment to its activity. Android Design Patterns is a website for developers who wish to better understand the Android application framework. onAttach() : The fragment instance is associated with an activity instance. An Activity with singleTask launchMode is allowed to have only one instance in the system (a. One of my favorite navigation pattern implementations is based on the "One-Activity-Multiple. Unlike a View, a Fragment represents a behavior or a portion of user interface in an activity. productFlavors. Android: the Single Activity, Multiple Fragments pattern | One Activi…. The above class concludes this Android tab example with Fragments and ViewPager. Anyway StatedFragment causes a pattern breaking since it was designed to do the different way as Android is designed with an assumption that it might be easier for Android developer to understand Fragment's state saving/restoring if it acts just like Activity does (View's state and Instance state are handled at the same time). The same instance is used across the application whenever it’s retrieved. When dealing with many tabs, or sharing common functionality between ActionBar tabs, it can be more efficient in terms of memory and performance to create a custom class that implements ActionBar. The following are top voted examples for showing how to use android. Android getting application context in Fragments By Ravi Tamada October 27, 2013 0 Comments If your activity class extends Activity, you can get application context using getApplicatoinContext(). For the other fragment, we have to switch to the next screen. a different Android Fragment or page. Fragments In Android Applications; Introduction In this article, you will see how to add a fragment dynamically at run time. This Fragment is a necessary. This fragment does not use a layout file to create a view. com/news-%26-archive/f/call-of-duty-modern. So, if your activity instance is destroyed and recreated, the state of the layout is restored to its previous state with no code required by you. A DialogFragment is a fragment that displays a modal window, floating on top of the current activity window. Regarding Fragments in 2017, the community is at a crossroads thanks to the efforts of Square and developers like Gabor, which isn’t a bad thing. Over the years, I've seen many different navigation pattern implementations in Android. Android Fragment Database I am trying to learn some android development and fragments but have run into a problem. Many Android developers, e. In this article I will go over a simple Android app utilizing the new API to perform injections within various scopes, including application scope, activity scope and fragment scope. By default, Fragments are destroyed and recreated along with their parent Activitys when a configuration change occurs. Below are the methods of fragment lifecycle. Android Instant app is an update to your existing Android app which makes it feasible for individuals to access a broader array of apps. Android Fragment are useful when we want to support multiple screen size. This diagram shows where plastics end up throughout their long. This begins a two part blog posting dedicated to explaining and exemplifying how Android (activity/fragment) state can be saved and restored. Following are important points about fragment − * A fragment has its own layout and its own behaviour with its own life cycle callbacks. MOST Web Documentation, Release 1. Using Google Volley library to build Android application for RESTful web services Leave a comment Posted by nanoexpert on October 7, 2013 Well this is not a big topic. 0新增的概念,在如何使用Android Fragment中做了关于Fragment的详细介绍。本文则主要是通过实例的方式让大家更直观的了解Fragment的使用方法。. While the microbes in a single drop of water could outnumber a small city’s population, the number of viruses in the same drop—the vast majority not harmful to humans could be even larger. Isn't it bad to have a single activity with multiple fragments? An activity is a single thing within the application, that serves one purpose. Several solutions for this single instance problem have been posted, but usually do not include running in Linux. If there is an existed Activity instance in the system, the whole Task hold the instance would be moved to top while Intent would be delivered through onNewIntent() method. In Common Navigation Paradigms cliffnotes, we discuss the various navigational structures available within Android apps. Gestural navigation allows the user to swipe left and right to step through pages of data. Using newInstance() to Instantiate a Fragment | Android Design Patterns. Fragments are for reusable ui or representing things in a different way on tablet vs mobile. Google added Bottom Navigation View in android design support library in it’s version 25. This page will walk through the android FragmentManager and FragmentTransaction example in which we will replace Fragment with another Fragment using Button OnClickListener. app entry (selecting the android. This begins a two part blog posting dedicated to explaining and exemplifying how Android (activity/fragment) state can be saved and restored. Seringkali kita perlu mencari sebuah instance fragment didalam layout activity. Activity class.