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diff --git a/docs/html/guide/components/fundamentals.jd b/docs/html/guide/components/fundamentals.jd index ce50022..9ac063e 100644 --- a/docs/html/guide/components/fundamentals.jd +++ b/docs/html/guide/components/fundamentals.jd @@ -4,24 +4,9 @@ page.title=Application Fundamentals <div id="qv-wrapper"> <div id="qv"> -<h2>Quickview</h2> -<ul> - <li>Android applications are composed of one or more application components (activities, -services, content providers, and broadcast receivers)</li> - <li>Each component performs a different role in the overall application behavior, and each -one can be activated individually (even by other applications)</li> - <li>The manifest file must declare all components in the application and should also declare -all application requirements, such as the minimum version of Android required and any hardware -configurations required</li> - <li>Non-code application resources (images, strings, layout files, etc.) should include -alternatives for different device configurations (such as different strings for different -languages and different layouts for different screen sizes)</li> -</ul> - - <h2>In this document</h2> <ol> -<li><a href="#Components">Application Components</a> +<li><a href="#Components">App Components</a> <ol> <li><a href="#ActivatingComponents">Activating components</a></li> </ol> @@ -29,98 +14,91 @@ languages and different layouts for different screen sizes)</li> <li><a href="#Manifest">The Manifest File</a> <ol> <li><a href="#DeclaringComponents">Declaring components</a></li> - <li><a href="#DeclaringRequirements">Declaring application requirements</a></li> + <li><a href="#DeclaringRequirements">Declaring app requirements</a></li> </ol> </li> -<li><a href="#Resources">Application Resources</a></li> +<li><a href="#Resources">App Resources</a></li> </ol> </div> </div> -<p>Android applications are written in the Java programming language. The Android SDK tools compile -the code—along with any data and resource files—into an <i>Android package</i>, an -archive file with an {@code .apk} suffix. All the code in a single {@code .apk} file is considered -to be one application and is the file that Android-powered devices use to install the -application.</p> +<p>Android apps are written in the Java programming language. The Android SDK tools compile +your code—along with any data and resource files—into an APK: an <i>Android package</i>, +which is an archive file with an {@code .apk} suffix. One APK file contains all the contents +of an Android app and is the file that Android-powered devices use to install the app.</p> -<p>Once installed on a device, each Android application lives in its own security sandbox: </p> +<p>Once installed on a device, each Android app lives in its own security sandbox: </p> <ul> - <li>The Android operating system is a multi-user Linux system in which each application is a + <li>The Android operating system is a multi-user Linux system in which each app is a different user.</li> -<li>By default, the system assigns each application a unique Linux user ID (the ID is used only by -the system and is unknown to the application). The system sets permissions for all the files in an -application so that only the user ID assigned to that application can access them. </li> +<li>By default, the system assigns each app a unique Linux user ID (the ID is used only by +the system and is unknown to the app). The system sets permissions for all the files in an +app so that only the user ID assigned to that app can access them. </li> -<li>Each process has its own virtual machine (VM), so an application's code runs in isolation from -other applications.</li> +<li>Each process has its own virtual machine (VM), so an app's code runs in isolation from +other apps.</li> -<li>By default, every application runs in its own Linux process. Android starts the process when any -of the application's components need to be executed, then shuts down the process when it's no longer -needed or when the system must recover memory for other applications.</li> +<li>By default, every app runs in its own Linux process. Android starts the process when any +of the app's components need to be executed, then shuts down the process when it's no longer +needed or when the system must recover memory for other apps.</li> </ul> <p>In this way, the Android system implements the <em>principle of least privilege</em>. That is, -each application, by default, has access only to the components that it requires to do its work and -no more. This creates a very secure environment in which an application cannot access parts of +each app, by default, has access only to the components that it requires to do its work and +no more. This creates a very secure environment in which an app cannot access parts of the system for which it is not given permission.</p> -<p>However, there are ways for an application to share data with other applications and for an -application to access system services:</p> +<p>However, there are ways for an app to share data with other apps and for an +app to access system services:</p> <ul> - <li>It's possible to arrange for two applications to share the same Linux user ID, in which case -they are able to access each other's files. To conserve system resources, applications with the + <li>It's possible to arrange for two apps to share the same Linux user ID, in which case +they are able to access each other's files. To conserve system resources, apps with the same user ID can also arrange to run in the same Linux process and share the same VM (the -applications must also be signed with the same certificate).</li> - <li>An application can request permission to access device data such as the user's +apps must also be signed with the same certificate).</li> + <li>An app can request permission to access device data such as the user's contacts, SMS messages, the mountable storage (SD card), camera, Bluetooth, and more. All -application permissions must be granted by the user at install time.</li> +app permissions must be granted by the user at install time.</li> </ul> -<p>That covers the basics regarding how an Android application exists within the system. The rest of +<p>That covers the basics regarding how an Android app exists within the system. The rest of this document introduces you to:</p> <ul> - <li>The core framework components that define your application.</li> + <li>The core framework components that define your app.</li> <li>The manifest file in which you declare components and required device features for your -application.</li> - <li>Resources that are separate from the application code and allow your application to +app.</li> + <li>Resources that are separate from the app code and allow your app to gracefully optimize its behavior for a variety of device configurations.</li> </ul> -<!-- -<p class="note"><strong>Tip:</strong> If you're new to Android development, we suggest that you -follow the Beginner's Path link at the bottom of this page. For each document in the Application -Fundamentals, the Beginner's Path points you to the document we suggest you read next, in order -to get up to speed on the core Android concepts.</p> ---> -<h2 id="Components">Application Components</h2> +<h2 id="Components">App Components</h2> -<p>Application components are the essential building blocks of an Android application. Each -component is a different point through which the system can enter your application. Not all +<p>App components are the essential building blocks of an Android app. Each +component is a different point through which the system can enter your app. Not all components are actual entry points for the user and some depend on each other, but each one exists as its own entity and plays a specific role—each one is a unique building block that -helps define your application's overall behavior.</p> +helps define your app's overall behavior.</p> -<p>There are four different types of application components. Each type serves a distinct purpose +<p>There are four different types of app components. Each type serves a distinct purpose and has a distinct lifecycle that defines how the component is created and destroyed.</p> -<p>Here are the four types of application components:</p> +<p>Here are the four types of app components:</p> <dl> <dt><b>Activities</b></dt> <dd>An <i>activity</i> represents a single screen with a user interface. For example, -an email application might have one activity that shows a list of new +an email app might have one activity that shows a list of new emails, another activity to compose an email, and another activity for reading emails. Although -the activities work together to form a cohesive user experience in the email application, each one -is independent of the others. As such, a different application can start any one of these -activities (if the email application allows it). For example, a camera application can start the -activity in the email application that composes new mail, in order for the user to share a picture. +the activities work together to form a cohesive user experience in the email app, each one +is independent of the others. As such, a different app can start any one of these +activities (if the email app allows it). For example, a camera app can start the +activity in the email app that composes new mail, in order for the user to share a picture. <p>An activity is implemented as a subclass of {@link android.app.Activity} and you can learn more about it in the <a href="{@docRoot}guide/components/activities.html">Activities</a> @@ -133,7 +111,7 @@ developer guide.</p> <dd>A <i>service</i> is a component that runs in the background to perform long-running operations or to perform work for remote processes. A service does not provide a user interface. For example, a service might play music in the background while -the user is in a different application, or it might fetch data over the network without +the user is in a different app, or it might fetch data over the network without blocking user interaction with an activity. Another component, such as an activity, can start the service and let it run or bind to it in order to interact with it. @@ -145,21 +123,21 @@ guide.</p> <dt><b>Content providers</b></dt> -<dd>A <i>content provider</i> manages a shared set of application data. You can store the data in +<dd>A <i>content provider</i> manages a shared set of app data. You can store the data in the file system, an SQLite database, on the web, or any other persistent storage location your -application can access. Through the content provider, other applications can query or even modify +app can access. Through the content provider, other apps can query or even modify the data (if the content provider allows it). For example, the Android system provides a content -provider that manages the user's contact information. As such, any application with the proper +provider that manages the user's contact information. As such, any app with the proper permissions can query part of the content provider (such as {@link android.provider.ContactsContract.Data}) to read and write information about a particular person. <p>Content providers are also useful for reading and writing data that is private to your -application and not shared. For example, the <a -href="{@docRoot}resources/samples/NotePad/index.html">Note Pad</a> sample application uses a +app and not shared. For example, the <a +href="{@docRoot}resources/samples/NotePad/index.html">Note Pad</a> sample app uses a content provider to save notes.</p> <p>A content provider is implemented as a subclass of {@link android.content.ContentProvider} -and must implement a standard set of APIs that enable other applications to perform +and must implement a standard set of APIs that enable other apps to perform transactions. For more information, see the <a href="{@docRoot}guide/topics/providers/content-providers.html">Content Providers</a> developer guide.</p> @@ -171,7 +149,7 @@ guide.</p> <dd>A <i>broadcast receiver</i> is a component that responds to system-wide broadcast announcements. Many broadcasts originate from the system—for example, a broadcast announcing that the screen has turned off, the battery is low, or a picture was captured. -Applications can also initiate broadcasts—for example, to let other applications know that +Apps can also initiate broadcasts—for example, to let other apps know that some data has been downloaded to the device and is available for them to use. Although broadcast receivers don't display a user interface, they may <a href="{@docRoot}guide/topics/ui/notifiers/notifications.html">create a status bar notification</a> @@ -188,26 +166,26 @@ see the {@link android.content.BroadcastReceiver} class.</p> -<p>A unique aspect of the Android system design is that any application can start another -application’s component. For example, if you want the user to capture a -photo with the device camera, there's probably another application that does that and your -application can use it, instead of developing an activity to capture a photo yourself. You don't -need to incorporate or even link to the code from the camera application. -Instead, you can simply start the activity in the camera application that captures a -photo. When complete, the photo is even returned to your application so you can use it. To the user, -it seems as if the camera is actually a part of your application.</p> +<p>A unique aspect of the Android system design is that any app can start another +app’s component. For example, if you want the user to capture a +photo with the device camera, there's probably another app that does that and your +app can use it, instead of developing an activity to capture a photo yourself. You don't +need to incorporate or even link to the code from the camera app. +Instead, you can simply start the activity in the camera app that captures a +photo. When complete, the photo is even returned to your app so you can use it. To the user, +it seems as if the camera is actually a part of your app.</p> -<p>When the system starts a component, it starts the process for that application (if it's not +<p>When the system starts a component, it starts the process for that app (if it's not already running) and instantiates the classes needed for the component. For example, if your -application starts the activity in the camera application that captures a photo, that activity -runs in the process that belongs to the camera application, not in your application's process. -Therefore, unlike applications on most other systems, Android applications don't have a single entry +app starts the activity in the camera app that captures a photo, that activity +runs in the process that belongs to the camera app, not in your app's process. +Therefore, unlike apps on most other systems, Android apps don't have a single entry point (there's no {@code main()} function, for example).</p> -<p>Because the system runs each application in a separate process with file permissions that -restrict access to other applications, your application cannot directly activate a component from -another application. The Android system, however, can. So, to activate a component in -another application, you must deliver a message to the system that specifies your <em>intent</em> to +<p>Because the system runs each app in a separate process with file permissions that +restrict access to other apps, your app cannot directly activate a component from +another app. The Android system, however, can. So, to activate a component in +another app, you must deliver a message to the system that specifies your <em>intent</em> to start a particular component. The system then activates the component for you.</p> @@ -217,7 +195,7 @@ start a particular component. The system then activates the component for you.</ broadcast receivers—are activated by an asynchronous message called an <em>intent</em>. Intents bind individual components to each other at runtime (you can think of them as the messengers that request an action from other components), whether the component belongs -to your application or another.</p> +to your app or another.</p> <p>An intent is created with an {@link android.content.Intent} object, which defines a message to activate either a specific component or a specific <em>type</em> of component—an intent @@ -273,21 +251,21 @@ href="{@docRoot}guide/topics/providers/content-providers.html">Content Providers <h2 id="Manifest">The Manifest File</h2> -<p>Before the Android system can start an application component, the system must know that the -component exists by reading the application's {@code AndroidManifest.xml} file (the "manifest" -file). Your application must declare all its components in this file, which must be at the root of -the application project directory.</p> +<p>Before the Android system can start an app component, the system must know that the +component exists by reading the app's {@code AndroidManifest.xml} file (the "manifest" +file). Your app must declare all its components in this file, which must be at the root of +the app project directory.</p> -<p>The manifest does a number of things in addition to declaring the application's components, +<p>The manifest does a number of things in addition to declaring the app's components, such as:</p> <ul> - <li>Identify any user permissions the application requires, such as Internet access or + <li>Identify any user permissions the app requires, such as Internet access or read-access to the user's contacts.</li> <li>Declare the minimum <a href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#ApiLevels">API Level</a> -required by the application, based on which APIs the application uses.</li> - <li>Declare hardware and software features used or required by the application, such as a camera, +required by the app, based on which APIs the app uses.</li> + <li>Declare hardware and software features used or required by the app, such as a camera, bluetooth services, or a multitouch screen.</li> - <li>API libraries the application needs to be linked against (other than the Android framework + <li>API libraries the app needs to be linked against (other than the Android framework APIs), such as the <a href="http://code.google.com/android/add-ons/google-apis/maps-overview.html">Google Maps library</a>.</li> @@ -297,7 +275,7 @@ library</a>.</li> <h3 id="DeclaringComponents">Declaring components</h3> -<p>The primary task of the manifest is to inform the system about the application's components. For +<p>The primary task of the manifest is to inform the system about the app's components. For example, a manifest file can declare an activity as follows: </p> <pre> @@ -314,7 +292,7 @@ example, a manifest file can declare an activity as follows: </p> <p>In the <code><a href="{@docRoot}guide/topics/manifest/application-element.html"><application></a></code> element, the {@code android:icon} attribute points to resources for an icon that identifies the -application.</p> +app.</p> <p>In the <code><a href="{@docRoot}guide/topics/manifest/activity-element.html"><activity></a></code> element, @@ -322,7 +300,7 @@ the {@code android:name} attribute specifies the fully qualified class name of t android.app.Activity} subclass and the {@code android:label} attributes specifies a string to use as the user-visible label for the activity.</p> -<p>You must declare all application components this way:</p> +<p>You must declare all app components this way:</p> <ul> <li><code><a href="{@docRoot}guide/topics/manifest/activity-element.html"><activity></a></code> elements @@ -345,7 +323,7 @@ receivers can be either declared in the manifest or created dynamically in code {@link android.content.BroadcastReceiver} objects) and registered with the system by calling {@link android.content.Context#registerReceiver registerReceiver()}.</p> -<p>For more about how to structure the manifest file for your application, see <a +<p>For more about how to structure the manifest file for your app, see <a href="{@docRoot}guide/topics/manifest/manifest-intro.html">The AndroidManifest.xml File</a> documentation. </p> @@ -356,28 +334,43 @@ documentation. </p> <p>As discussed above, in <a href="#ActivatingComponents">Activating Components</a>, you can use an {@link android.content.Intent} to start activities, services, and broadcast receivers. You can do so by explicitly naming the target component (using the component class name) in the intent. However, -the real power of intents lies in the concept of intent actions. With intent actions, you simply -describe the type of action you want to perform (and optionally, the data upon which you’d like to +the real power of intents lies in the concept of <em>implicit intents</em>. An implicit intent +simply describe the type of action to perform (and optionally, the data upon which you’d like to perform the action) and allow the system to find a component on the device that can perform the action and start it. If there are multiple components that can perform the action described by the intent, then the user selects which one to use.</p> <p>The way the system identifies the components that can respond to an intent is by comparing the -intent received to the <i>intent filters</i> provided in the manifest file of other applications on +intent received to the <i>intent filters</i> provided in the manifest file of other apps on the device.</p> -<p>When you declare a component in your application's manifest, you can optionally include -intent filters that declare the capabilities of the component so it can respond to intents -from other applications. You can declare an intent filter for your component by +<p>When you declare an activity in your app's manifest, you can optionally include +intent filters that declare the capabilities of the activity so it can respond to intents +from other apps. You can declare an intent filter for your component by adding an <a href="{@docRoot}guide/topics/manifest/intent-filter-element.html">{@code <intent-filter>}</a> element as a child of the component's declaration element.</p> -<p>For example, an email application with an activity for composing a new email might declare an -intent filter in its manifest entry to respond to "send" intents (in order to send email). An -activity in your application can then create an intent with the “send” action ({@link -android.content.Intent#ACTION_SEND}), which the system matches to the email application’s “send” -activity and launches it when you invoke the intent with {@link android.app.Activity#startActivity -startActivity()}.</p> +<p>For example, if you've built an email app with an activity for composing a new email, you can +declare an intent filter to respond to "send" intents (in order to send a new email) like this:</p> +<pre> +<manifest ... > + ... + <application ... > + <activity android:name="com.example.project.ComposeEmailActivity"> + <intent-filter> + <action android:name="android.intent.action.SEND" /> + <data android:type="*/*" /> + <category android:name="android.intent.category.DEFAULT" /> + </intent-filter> + </activity> + </application> +</manifest> +</pre> + +<p>Then, if another app creates an intent with the {@link +android.content.Intent#ACTION_SEND} action and pass it to {@link android.app.Activity#startActivity +startActivity()}, the system may start your activity so the user can draft and send an +email.</p> <p>For more about creating intent filters, see the <a href="{@docRoot}guide/components/intents-filters.html">Intents and Intent Filters</a> document. @@ -385,102 +378,57 @@ href="{@docRoot}guide/components/intents-filters.html">Intents and Intent Filter -<h3 id="DeclaringRequirements">Declaring application requirements</h3> +<h3 id="DeclaringRequirements">Declaring app requirements</h3> <p>There are a variety of devices powered by Android and not all of them provide the -same features and capabilities. In order to prevent your application from being installed on devices -that lack features needed by your application, it's important that you clearly define a profile for -the types of devices your application supports by declaring device and software requirements in your +same features and capabilities. In order to prevent your app from being installed on devices +that lack features needed by your app, it's important that you clearly define a profile for +the types of devices your app supports by declaring device and software requirements in your manifest file. Most of these declarations are informational only and the system does not read them, but external services such as Google Play do read them in order to provide filtering -for users when they search for applications from their device.</p> - -<p>For example, if your application requires a camera and uses APIs introduced in Android 2.1 (<a -href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#ApiLevels">API Level</a> 7), you should declare these as -requirements in your manifest file. That way, devices that do <em>not</em> have a camera and have an -Android version <em>lower</em> than 2.1 cannot install your application from Google Play.</p> +for users when they search for apps from their device.</p> -<p>However, you can also declare that your application uses the camera, but does not -<em>require</em> it. In that case, your application must perform a check at runtime to determine -if the device has a camera and disable any features that use the camera if one is not available.</p> +<p>For example, if your app requires a camera and uses APIs introduced in Android 2.1 (<a +href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#ApiLevels">API Level</a> 7), +you should declare these as requirements in your manifest file like this:</p> -<p>Here are some of the important device characteristics that you should consider as you design and -develop your application:</p> - -<dl> - <dt>Screen size and density</dt> - <dd>In order to categorize devices by their screen type, Android defines two characteristics for -each device: screen size (the physical dimensions of the screen) and screen density (the physical -density of the pixels on the screen, or dpi—dots per inch). To simplify all the different -types of screen configurations, the Android system generalizes them into select groups that make -them easier to target. -<p>The screen sizes are: small, normal, large, and extra large.<br/> -The screen densities are: low density, medium density, high density, and extra high density.</p> - -<p>By default, your application is compatible with all screen sizes and densities, -because the Android system makes the appropriate adjustments to your UI layout and image -resources. However, you should create specialized layouts for certain screen sizes and provide -specialized images for certain densities, using alternative layout resources, and by declaring in -your manifest exactly which screen sizes your application supports with the <a -href="{@docRoot}guide/topics/manifest/supports-screens-element.html">{@code -<supports-screens>}</a> element.</p> -<p>For more information, see the <a -href="{@docRoot}guide/practices/screens_support.html">Supporting Multiple Screens</a> -document.</p></dd> - - <dt>Input configurations</dt> - <dd>Many devices provide a different type of user input mechanism, such as a hardware keyboard, a -trackball, or a five-way navigation pad. If your application requires a particular kind of input -hardware, then you should declare it in your manifest with the <a -href="{@docRoot}guide/topics/manifest/uses-configuration-element.html">{@code -<uses-configuration>}</a> element. However, it is rare that an application should require -a certain input configuration.</dd> - - <dt>Device features</dt> - <dd>There are many hardware and software features that may or may not exist on a given -Android-powered device, such as a camera, a light sensor, bluetooth, a certain -version of OpenGL, or the fidelity of the touchscreen. You should never assume that a certain -feature is available on all Android-powered devices (other than the availability of the standard -Android library), so you should declare any features used by your application with the <a -href="{@docRoot}guide/topics/manifest/uses-feature-element.html">{@code <uses-feature>}</a> -element.</dd> - - <dt>Platform Version</dt> - <dd>Different Android-powered devices often run different versions of the Android platform, -such as Android 1.6 or Android 2.3. Each successive version often includes additional APIs not -available in the previous version. In order to indicate which set of APIs are available, each -platform version specifies an <a -href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#ApiLevels">API Level</a> (for example, Android 1.0 is API Level -1 and Android 2.3 is API Level 9). If you use any APIs that were added to the platform after -version 1.0, you should declare the minimum API Level in which those APIs were introduced using the -<a href="{@docRoot}guide/topics/manifest/uses-sdk-element.html">{@code <uses-sdk>}</a> -element.</dd> -</dl> - -<p>It's important that you declare all such requirements for your application, because, when you -distribute your application on Google Play, the store uses these declarations to filter which -applications are available on each device. As such, your application should be available only to -devices that meet all your application requirements.</p> - -<p>For more information about how Google Play filters applications based on these (and other) -requirements, see the <a href="{@docRoot}google/play/filters.html">Filters on Google Play</a> +<pre> +<manifest ... > + <uses-feature android:name="android.hardware.camera.any" + android:required="true" /> + <uses-sdk android:minSdkVersion="7" android:targetSdkVersion="19" /> + ... +</manifest> +</pre> + +<p>Now, devices that do <em>not</em> have a camera and have an +Android version <em>lower</em> than 2.1 cannot install your app from Google Play.</p> + +<p>However, you can also declare that your app uses the camera, but does not +<em>require</em> it. In that case, your app must set the <a href= +"{@docRoot}guide/topics/manifest/uses-feature-element.html#required">{@code required}</a> +attribute to {@code "false"} and check at runtime whether +the device has a camera and disable any camera features as appropriate.</p> + +<p>More information about how you can manage your app's compatibility with different devices +is provided in the <a href="{@docRoot}guide/practices/compatibility.html">Device Compatibility</a> document.</p> -<h2 id="Resources">Application Resources</h2> +<h2 id="Resources">App Resources</h2> -<p>An Android application is composed of more than just code—it requires resources that are +<p>An Android app is composed of more than just code—it requires resources that are separate from the source code, such as images, audio files, and anything relating to the visual -presentation of the application. For example, you should define animations, menus, styles, colors, -and the layout of activity user interfaces with XML files. Using application resources makes it easy -to update various characteristics of your application without modifying code and—by providing -sets of alternative resources—enables you to optimize your application for a variety of +presentation of the app. For example, you should define animations, menus, styles, colors, +and the layout of activity user interfaces with XML files. Using app resources makes it easy +to update various characteristics of your app without modifying code and—by providing +sets of alternative resources—enables you to optimize your app for a variety of device configurations (such as different languages and screen sizes).</p> <p>For every resource that you include in your Android project, the SDK build tools define a unique -integer ID, which you can use to reference the resource from your application code or from -other resources defined in XML. For example, if your application contains an image file named {@code +integer ID, which you can use to reference the resource from your app code or from +other resources defined in XML. For example, if your app contains an image file named {@code logo.png} (saved in the {@code res/drawable/} directory), the SDK tools generate a resource ID named {@code R.drawable.logo}, which you can use to reference the image and insert it in your user interface.</p> @@ -504,15 +452,45 @@ depending on the orientation, you can define two different layouts and apply the qualifier to each layout's directory name. Then, the system automatically applies the appropriate layout depending on the current device orientation.</p> -<p>For more about the different kinds of resources you can include in your application and how -to create alternative resources for various device configurations, see the <a -href="{@docRoot}guide/topics/resources/index.html">Application Resources</a> developer guide.</p> - - -<!-- -<h2>Beginner's Path</h2> +<p>For more about the different kinds of resources you can include in your application and how to +create alternative resources for different device configurations, read <a href= +"{@docRoot}guide/topics/resources/providing-resources.html">Providing Resources</a>.</p> + + + +<div class="next-docs"> +<div class="col-6"> + <h2 class="norule">Continue reading about:</h2> + <dl> + <dt><a href="{@docRoot}guide/components/intents-filters.html">Intents and Intent Filters</a> + </dt> + <dd>Information about how to use the {@link android.content.Intent} APIs to + activate app components, such as activities and services, and how to make your app components + available for use by other apps.</dd> + <dt><a href="{@docRoot}guide/components/activities.html">Activities</a></dt> + <dd>Information about how to create an instance of the {@link android.app.Activity} class, + which provides a distinct screen in your application with a user interface.</dd> + <dt><a +href="{@docRoot}guide/topics/resources/providing-resources.html">Providing Resources</a></dt> + <dd>Information about how Android apps are structured to separate app resources from the + app code, including how you can provide alternative resources for specific device + configurations. + </dd> + </dl> +</div> +<div class="col-6"> + <h2 class="norule">You might also be interested in:</h2> + <dl> + <dt><a href="{@docRoot}guide/practices/compatibility.html" + >Device Compatibility</a></dt> + <dd>Information about Android works on different types of devices and an introduction + to how you can optimize your app for each device or restrict your app's availability + to different devices.</dd> + <dt><a href="{@docRoot}guide/topics/security/permissions.html" + >System Permissions</a></dt> + <dd>Information about how Android restricts app access to certain APIs with a permission + system that requires the user's consent for your app to use those APIs.</dd> + </dl> +</div> +</div> -<p>For a close look at implementing activities—the components your users use to -interact with your application—continue with the <b><a -href="{@docRoot}guide/components/activities.html">Activities</a></b> document.</p> ---> |