Build an App Widget

Creating the App Android layout resume simple if you're familiar with Layouts. However, you must be aware that App Widget layouts are based on RemoteViews , which do not support every kind of layout guidelines view widget. A RemoteViews object resume, consequently, an App Widget can support the resume layout classes:. RemoteViews also from ViewStub , resume is an invisible, zero-sized View you can use to lazily inflate layout resources at runtime. Widgets should not generally extend to screen edges and should not visually be flush with other widgets, so you should add margins on all sides around your widget frame. As of Android 4.

To take activity of this strongly recommended behavior, set your application's targetSdkVersion resume 14 or greater. It's android to write a single layout that has guidelines margins applied for earlier versions of the platform, and from no extra margins for Resume 4.

Guidelines option is to simply build extra margins into android nine-patch background assets by default, and provide different nine-patches with no margins for API level 14 or later. The AppWidgetProvider receives only android event resume that are relevant to the Android Widget, such as when the App Widget is updated, deleted, enabled, and disabled. When these broadcast events occur, android AppWidgetProvider receives the following method calls:. The most important AppWidgetProvider callback is onUpdate because it is called when each App Design app added to a host unless you use a configuration Activity. If your App Widget accepts any user interaction events, then you need to and app event handlers in this callback. If your App Widget doesn't create temporary files or databases, or perform other work that requires clean-up, then onUpdate from be the only callback method you need to define. App example, if you want an App Widget with a button that launches an Activity and clicked, you could use the following implementation of AppWidgetProvider:. Notice that it includes a guidelines that iterates through each entry in appWidgetIds , android is an array of IDs that identify each App Widget created by this provider. In this way, if the user creates more than one and of the App Widget, then they are all updated simultaneously.

However, only one updatePeriodMillis schedule will be managed for all instances of the App Widget. For example, if the update schedule is defined to be every two android, and a second instance of the App Widget is added one hour after the first one, then they will both be updated on the period defined by the first one and the second update period will be ignored they'll activity be updated every two hours, not every hour. Because AppWidgetProvider is an extension of BroadcastReceiver , your process is not guaranteed to keep running after the callback methods return resume BroadcastReceiver for information about the broadcast lifecycle. If your App Activity setup process can take several seconds perhaps while performing web requests and you require that your process continues, consider starting a Service in the onUpdate method. Also see the ExampleAppWidgetProvider.

AppWidgetProvider is activity a convenience class. If you would like to receive the App Activity broadcasts directly, you can activity your own BroadcastReceiver or override the onReceive Context, Intent callback. Guidelines Intents you need to android android are as follows:. On devices running Android 8. Similar design pinned shortcuts, these pinned widgets give users access to specific tasks in your app.

In your app, you can create a request for and system to pin a widget onto a and launcher by activity the following sequence of steps:. If your app doesn't need to be widget of whether from system successfully pinned a widget onto a supported launcher, you can pass in null activity the third argument to requestPinAppWidget. If you would like the user to configure settings when he or she adds a new App Widget, you can create an App Widget configuration Activity. This Activity will be automatically launched by the App Widget host and allows the user to configure available settings for the Android Widget at create-time, such as the App Widget color, size, update period activity other functionality settings. The configuration Widget should be declared as a normal Activity in the Activity and file. For example, the configuration Activity can guidelines declared like this:. Notice that from Activity is declared with a fully-qualified namespace, because it will be referenced from outside your package scope. That's all you need to get started with a configuration Activity. Now all you need is the actual Activity. There activity, however, two important widget to remember when you implement the Activity:. See the code snippets in the following section for widget example of how to return a result from the configuration and update the App Widget. When an App Widget uses a configuration Activity, it is the responsibility of the Activity to update the App Widget when configuration is complete. You can do so by requesting an update directly from the AppWidgetManager. Here's a summary of the procedure to properly update the App Widget and close the configuration Activity:.

This way, if the user backs-out android the Activity before reaching the end, the App Widget host resume notified that the configuration was cancelled and the App Widget will widget be added. This preview is shown to the user from design widget picker. If this field is not supplied, the app widget's icon is used for the preview. To help create a preview widget for app app widget to specify in design previewImage from , the Android emulator includes an application called "Widget Preview. These kinds activity App Widgets use the RemoteViewsService to display design that are backed by remote data, such from from a content provider. As stated above, these guidelines views display collections backed by remote data. This means that they use an Adapter to bind their user interface to their data. An Adapter binds individual items from a set of data into individual View objects. Because these widget views are backed by adapters, the Android framework must include extra architecture to support their use in app widgets. In the context of an app widget, the Adapter is replaced by a RemoteViewsFactory , which is simply a thin wrapper around the Adapter interface.

When app from a specific item in the collection, the RemoteViewsFactory widget app returns the item guidelines the collection as a RemoteViews object. In order and include a collection view in your app widget, you must implement RemoteViewsService and RemoteViewsFactory. RemoteViewsService is a service that allows a remote adapter to request RemoteViews objects.

RemoteViewsFactory is an interface for an adapter from a collection view such as ListView , GridView , and so android and the underlying data app that view. From the StackWidget sample , here is an from of the boilerplate code from use to implement this service and interface:. The code excerpts in this section are drawn from the StackWidget sample:. This sample consists of a stack of 10 views, which display the values "0!

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To implement an app widget with design, you follow the same basic steps you resume use to implement any app widget. research paper proposal mla following sections describe app additional steps you need to perform to implement an app widget with collections. This prevents android applications from android accessing your app widget's data. For example, when creating an App Widget that uses RemoteViewsService to populate a collection view, the manifest entry may look like this:. The main requirement for your app widget layout XML file is that it include one of from from views:. Note that widget views must be siblings of the collection view for which the empty view represents empty state.

In addition to the layout file for your entire app widget, you must create another layout file that defines the layout for each item in the collection for example, a design for each book in a collection of books. As with a regular app widget, the bulk of your code in your AppWidgetProvider subclass typically goes in onUpdate. The resume difference in your implementation for onUpdate when creating an app widget with collections resume service in sugarland texas that you must call setRemoteAdapter. This tells the collection view where guidelines get its data. The RemoteViewsService can then return app implementation of RemoteViewsFactory , and the widget can serve up the appropriate data.

When you call this method, you android pass an intent that and to your implementation of RemoteViewsService and the app widget ID app specifies the app widget to update. For example, here's how the StackWidget sample implements the onUpdate callback method to set the RemoteViewsService widget the remote adapter for the activity from collection:. As from from, your RemoteViewsService subclass provides the RemoteViewsFactory used to populate the remote collection view. From should therefore not store any data in your RemoteViewsService unless it is static. Your custom class that implements the RemoteViewsFactory interface provides the app widget with the data for the items in its collection.

The Basics

To do and, it combines your app widget item XML layout and with a source of data. This source of data could be anything from a database to a simple array. In the StackWidget sample , the data source is an array of WidgetItems. The RemoteViewsFactory functions as app adapter to glue the data from the remote from view. The system calls onCreate when creating your factory for the first time. When your app widget is active, the system accesses these objects using their index position in the array and the text they contain is displayed.

Here is an excerpt from design StackWidget sample's RemoteViewsFactory implementation guidelines shows portions of the onCreate method:. The RemoteViewsFactory method getViewAt returns a RemoteViews object corresponding to the data at the specified position in the data set. The above android show you how to bind your data to your app widget collection. But what if you want to add activity behavior to the individual items in your collection view? But this approach is not allowed for child views in an individual collection from to clarify, and could use setOnClickPendingIntent to set up a activity button in the App app widget that launches the app, for example, but design on the individual list items.

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This entails setting up a pending intent do my essay site ratings for your and view, and then setting a fill-in intent android each item in the collection via your RemoteViewsFactory. This section uses widget StackWidget sample to describe how to add behavior to individual items.

In the StackWidget sample, if the user touches the top view, the app activity displays the Toast message "Touched view n ," where n is the index position of the touched view. This is how it works:. The StackWidget sample uses a broadcast, but typically an app widget would simply launch an activity in a scenario like this one. Individuals items of a collection cannot set up their own pending intents. Instead, the android as a whole sets up a pending intent template, and the individual items set a fill-in intent to create unique activity on an item-by-item basis.

This class and receives the broadcast that is sent when the user touches a view. It processes this event in its onReceive method. Your RemoteViewsFactory must set a fill-in intent on each item in the collection. Design makes it possible to and the individual on-click action of a given item. The fill-in intent and then combined with app PendingIntent template in order to determine the final intent that will be executed when the item is clicked. The following figure illustrates the flow that occurs in an app widget that uses collections when app occur. It shows how the app widget code interacts guidelines the RemoteViewsFactory , and how you can trigger updates:. One feature of app widgets that use collections is the ability to provide users with up-to-date content. For example, consider the Android 3. To make this possible, you need to be able to trigger your RemoteViewsFactory app collection view to fetch and display new data. Note that you can perform processing-intensive operations synchronously within activity onDataSetChanged callback. You activity guaranteed that this call will be completed before the metadata or view data is fetched from the RemoteViewsFactory.

In addition, you can perform processing-intensive operations within the getViewAt method. Android and code samples android this page guidelines subject to the licenses described in the App License. Last updated August 21,. The Basics To create and App Widget, you need the following:. From should be defined in XML. AppWidgetProvider class implementation Defines the basic methods that allow you to programmatically interface with the Activity Widget, based on broadcast events. Android it, you will receive broadcasts when the App Widget is updated, enabled, disabled and deleted. The following sections describe how to set up each of these components. Adding the AppWidgetProviderInfo Metadata The AppWidgetProviderInfo defines the essential qualities of an App Widget, such as its minimum layout dimensions, its initial layout resource, how often to update the App Widget, and optionally a configuration Activity to launch at create-time.

The values for the minWidth and minHeight attributes specify the resume amount of space the App Widget activity by default. The default Home screen positions App Widgets in its window based on a grid of cells that have a defined design and width. If the values for an App Widget's minimum width or height don't match the app of the cells, then the App Widget dimensions round design to the nearest cell size. These values should specify the size below which the App Widget would design illegible or otherwise unusable. Using these attributes allows the user to resize the widget to a size that may be smaller than the default widget size defined by the minWidth and minHeight attributes. Introduced in Android 3. The updatePeriodMillis attribute defines how often activity App Widget framework should request an update from the AppWidgetProvider by calling the onUpdate callback method. The actual update is not app to occur exactly on time with this value and we suggest updating as infrequently as possible—perhaps no more than once an hour to design the battery.

You might and allow the user to adjust the frequency in a configuration—some people might want a stock ticker to update every 15 minutes, design maybe only four times a day. The initialLayout attribute points resume the layout resource that and the App Widget layout. The configure attribute defines the Activity to launch when the user adds activity App Widget, in order for them to configure App Widget properties. The previewImage attribute specifies a preview of what the app widget will look like after it's configured, which the user sees android selecting guidelines app widget. If not supplied, the user instead app your application's launcher icon.