| page.title=Glossary |
| excludeFromSuggestions=true |
| @jd:body |
| |
| <p>The list below defines some of the basic terminology of the Android platform. </p> |
| <dl> |
| <dt id="apk">.apk file</dt> <dd>Android application package file. Each |
| Android application is compiled and packaged in a single file that |
| includes all of the application's code (.dex files), resources, assets, |
| and manifest file. The application package file can have any name but |
| <em>must</em> use the <code>.apk</code> extension. For example: |
| <code>myExampleAppname.apk</code>. For convenience, an application package |
| file is often referred to as an ".apk". |
| <p>Related: <a href="#application">Application</a>.</p> |
| </dd> |
| |
| <dt id="dex">.dex file </dt> |
| <dd>Compiled Android application code file. |
| <p>Android programs are compiled into .dex (Dalvik Executable) files, which |
| are in turn zipped into a single .apk file on the device. .dex files can |
| be created by automatically translating compiled applications written in |
| the Java programming language.</dd> |
| |
| <dt id="action">Action</dt> |
| <dd>A description of something that an Intent sender wants done. An action is |
| a string value assigned to an Intent. Action strings can be defined by Android |
| or by a third-party developer. For example, android.intent.action.VIEW |
| for a Web URL, or com.example.rumbler.SHAKE_PHONE for a custom application |
| to vibrate the phone. |
| <p>Related: <a href="#intent">Intent</a>.</p> |
| </dd> |
| |
| <dt id="activity">Activity</dt> |
| <dd>A single screen in an application, with supporting Java code, derived |
| from the {@link android.app.Activity} class. Most commonly, an activity is |
| visibly represented by a full screen window that can receive and handle UI |
| events and perform complex tasks, because of the Window it uses to render |
| its window. Though an Activity is typically full screen, it can also be |
| floating or transparent.</dd> |
| |
| <dt id="adb">adb</dt> |
| <dd>Android Debug Bridge, a command-line debugging application included with the |
| SDK. It provides tools to browse the device, copy tools on the device, and |
| forward ports for debugging. If you are developing in Eclipse using the |
| ADT Plugin, adb is integrated into your development environment. See |
| <a href="{@docRoot}tools/help/adb.html">Android Debug Bridge</a> |
| for more information. </dd> |
| |
| <dt id="application">Application</dt> |
| <dd>From a component perspective, an Android application consists of one |
| or more activities, services, listeners, and intent receivers. From a |
| source file perspective, an Android application consists of code, |
| resources, assets, and a single manifest. During compilation, these files |
| are packaged in a single file called an application package file (.apk). |
| <p>Related: <a href="#apk">.apk</a>, <a href="#activity">Activity</a></p></dd> |
| |
| <dt id="canvas">Canvas</dt> |
| <dd>A drawing surface that handles compositing of the actual bits against |
| a Bitmap or Surface object. It has methods for standard computer drawing |
| of bitmaps, lines, circles, rectangles, text, and so on, and is bound to a |
| Bitmap or Surface. Canvas is the simplest, easiest way to draw 2D objects |
| on the screen. However, it does not support hardware acceleration, as |
| OpenGL ES does. The base class is {@link android.graphics.Canvas}. |
| <p>Related: <a href="#drawable">Drawable</a>, <a href="#opengles">OpenGL |
| ES</a>.</p></dd> |
| |
| <dt id="contentprovider">Content Provider</dt> |
| <dd>A data-abstraction layer that you can use to safely expose your |
| application's data to other applications. A content provider is built on |
| the {@link android.content.ContentProvider} class, which handles content |
| query strings of a specific format to return data in a specific format. |
| See <a href="{@docRoot}guide/topics/providers/content-providers.html"> |
| Content Providers</a> topic for more information. |
| <p>Related: <a href="#uri">URI Usage in Android</a></p></dd> |
| |
| <dt id="dalvik">Dalvik</dt> |
| <dd>The Android platform's virtual machine. The Dalvik VM is an |
| interpreter-only virtual machine that executes files in the Dalvik |
| Executable (.dex) format, a format that is optimized for efficient storage |
| and memory-mappable execution. The virtual machine is register-based, and |
| it can run classes compiled by a Java language compiler that have been |
| transformed into its native format using the included "dx" tool. |
| The VM runs on top of Posix-compliant operating systems, which it relies |
| on for underlying functionality (such as threading and low level memory |
| management). The Dalvik core class library is intended to provide a |
| familiar development base for those used to programming with Java Standard |
| Edition, but it is geared specifically to the needs of a small mobile |
| device.</dd> |
| |
| <dt id="ddms">DDMS</dt> |
| <dd>Dalvik Debug Monitor Service, a GUI debugging application included |
| with the SDK. It provides screen capture, log dump, and process |
| examination capabilities. If you are developing in Eclipse using the ADT |
| Plugin, DDMS is integrated into your development environment. See <a |
| href="{@docRoot}tools/debugging/ddms.html">Using DDMS</a> to learn more about the program.</dd> |
| |
| <dt id="dialog">Dialog</dt> <dd> A floating window that acts as a lightweight |
| form. A dialog can have button controls only and is intended to perform a |
| simple action (such as button choice) and perhaps return a value. A dialog |
| is not intended to persist in the history stack, contain complex layout, |
| or perform complex actions. Android provides a default simple dialog for |
| you with optional buttons, though you can define your own dialog layout. |
| The base class for dialogs is {@link android.app.Dialog Dialog}. |
| <p>Related: <a href="#activity">Activity</a>.</p></dd> |
| |
| <dt id="drawable">Drawable</dt> |
| <dd>A compiled visual resource that can be used as a background, title, or |
| other part of the screen. A drawable is typically loaded into another UI |
| element, for example as a background image. A drawable is not able to |
| receive events, but does assign various other properties such as "state" |
| and scheduling, to enable subclasses such as animation objects or image |
| libraries. Many drawable objects are loaded from drawable resource files |
| — xml or bitmap files that describe the image. Drawable resources |
| are compiled into subclasses of {@link android.graphics.drawable}. For |
| more information about drawables and other resources, see <a |
| href="{@docRoot}guide/topics/resources/resources-i18n.html">Resources</a>. |
| <p>Related: <a href="#resources">Resources</a>, <a href="#canvas">Canvas |
| </a></p></dd> |
| |
| <dt id="intent">Intent</dt> |
| <dd>An message object that you can use to launch or communicate with other |
| applications/activities asynchronously. An Intent object is an instance of |
| {@link android.content.Intent}. It includes several criteria fields that you can |
| supply, to determine what application/activity receives the Intent and |
| what the receiver does when handling the Intent. Available criteria include |
| include the desired action, a category, a data string, the MIME type of |
| the data, a handling class, and others. An application sends |
| an Intent to the Android system, rather than sending it directly to |
| another application/activity. The application can send the Intent to a |
| single target application or it can send it as a broadcast, which can in |
| turn be handled by multiple applications sequentially. The Android system |
| is responsible for resolving the best-available receiver for each Intent, |
| based on the criteria supplied in the Intent and the Intent Filters |
| defined by other applications. For more information, see <a |
| href="{@docRoot}guide/components/intents-filters.html">Intents and |
| Intent Filters</a>. |
| <p>Related: <a href="#intentfilter">Intent Filter</a>, <a |
| href="#broadcastreceiver">Broadcast Receiver</a>.</p></dd> |
| |
| <dt id="intentfilter">Intent Filter</dt> |
| <dd>A filter object that an application declares in its manifest file, to |
| tell the system what types of Intents each of its components is willing to |
| accept and with what criteria. Through an intent filter, an application |
| can express interest in specific data types, Intent actions, URI formats, |
| and so on. When resolving an Intent, the system evaluates all of the |
| available intent filters in all applications and passes the Intent to the |
| application/activity that best matches the Intent and criteria. For more |
| information, see <a |
| href="{@docRoot}guide/components/intents-filters.html">Intents and |
| Intent Filters</a>. |
| <p>Related: <a href="#intent">Intent</a>, <a |
| href="#broadcastreceiver">Broadcast Receiver</a>.</p></dd> |
| |
| <dt id="broadcastreceiver">Broadcast Receiver </dt> |
| <dd>An application class that listens for Intents that are broadcast, |
| rather than being sent to a single target application/activity. The system |
| delivers a broadcast Intent to all interested broadcast receivers, which |
| handle the Intent sequentially. |
| <p>Related: <a href="#intent">Intent</a>, <a href="#intentfilter">Intent |
| Filter</a>.</p> </dd> |
| |
| <dt id="layoutresource">Layout Resource</dt> |
| <dd>An XML file that describes the layout of an Activity screen. |
| <p>Related: <a href="#resources">Resources</a></p></dd> |
| |
| <dt id="manifest">Manifest File</dt> |
| <dd>An XML file that each application must define, to describe the |
| application's package name, version, components (activities, intent |
| filters, services), imported libraries, and describes the various |
| activities, and so on. See <a |
| href="{@docRoot}guide/topics/manifest/manifest-intro.html">The |
| AndroidManifest.xml File</a> for complete information.</dd> |
| |
| <dt id="ninepatch">Nine-patch / 9-patch / Ninepatch image</dt> |
| <dd>A resizeable bitmap resource that can be used for backgrounds or other |
| images on the device. See <a |
| href="{@docRoot}guide/topics/resources/available-resources.html#ninepatch"> |
| Nine-Patch Stretchable Image</a> for more information. |
| <p>Related: <a href="#resources">Resources</a>.</p></dd> |
| |
| <dt id="opengles">OpenGL ES</dt> |
| <dd> Android provides OpenGL ES libraries that you can use for fast, |
| complex 3D images. It is harder to use than a Canvas object, but |
| better for 3D objects. The {@link android.opengl} and |
| {@link javax.microedition.khronos.opengles} packages expose |
| OpenGL ES functionality. |
| <p>Related: <a href="#canvas">Canvas</a>, <a href="#surface">Surface</a></p></dd> |
| |
| <dt id="resources">Resources</dt> |
| <dd>Nonprogrammatic application components that are external to the |
| compiled application code, but which can be loaded from application code |
| using a well-known reference format. Android supports a variety of |
| resource types, but a typical application's resources would consist of UI |
| strings, UI layout components, graphics or other media files, and so on. |
| An application uses resources to efficiently support localization and |
| varied device profiles and states. For example, an application would |
| include a separate set of resources for each supported local or device |
| type, and it could include layout resources that are specific to the |
| current screen orientation (landscape or portrait). For more information |
| about resources, see <a |
| href="{@docRoot}guide/topics/resources/index.html"> Resources and |
| Assets</a>. The resources of an application are always stored in the |
| <code>res/*</code> subfolders of the project. </dd> |
| |
| <dt id="service">Service</dt> |
| <dd>An object of class {@link android.app.Service} that runs in the |
| background (without any UI presence) to perform various persistent |
| actions, such as playing music or monitoring network activity. |
| <p>Related: <a href="#activity">Activity</a></p></dd> |
| |
| <dt id="surface">Surface</dt> |
| <dd>An object of type {@link android.view.Surface} representing a block of |
| memory that gets composited to the screen. A Surface holds a Canvas object |
| for drawing, and provides various helper methods to draw layers and resize |
| the surface. You should not use this class directly; use |
| {@link android.view.SurfaceView} instead. |
| <p>Related: <a href="#canvas">Canvas</a></p></dd> |
| |
| <dt id="surfaceview">SurfaceView</dt> |
| <dd>A View object that wraps a Surface for drawing, and exposes methods to |
| specify its size and format dynamically. A SurfaceView provides a way to |
| draw independently of the UI thread for resource-intensive operations |
| (such as games or camera previews), but it uses extra memory as a result. |
| SurfaceView supports both Canvas and OpenGL ES graphics. The base class is |
| {@link android.view.SurfaceView}. |
| <p>Related: <a href="#canvas">Surface</a></p></dd> |
| |
| <dt id="theme">Theme</dt> |
| <dd>A set of properties (text size, background color, and so on) bundled |
| together to define various default display settings. Android provides a |
| few standard themes, listed in {@link android.R.style} (starting with |
| "Theme_"). </dd> |
| |
| <dt id="uri">URIs in Android</dt> |
| <dd>Android uses URI strings as the basis for requesting data in a content |
| provider (such as to retrieve a list of contacts) and for requesting |
| actions in an Intent (such as opening a Web page in a browser). The URI |
| scheme and format is specialized according to the type of use, and an |
| application can handle specific URI schemes and strings in any way it |
| wants. Some URI schemes are reserved by system components. For example, |
| requests for data from a content provider must use the |
| <code>content://</code>. In an Intent, a URI using an <code>http://</code> |
| scheme will be handled by the browser. </dd> |
| |
| <dt id="view">View</dt> |
| <dd>An object that draws to a rectangular area on the screen and handles |
| click, keystroke, and other interaction events. A View is a base class for |
| most layout components of an Activity or Dialog screen (text boxes, |
| windows, and so on). It receives calls from its parent object (see |
| viewgroup, below)to draw itself, and informs its parent object about where |
| and how big it would like to be (which may or may not be respected by the |
| parent). For more information, see {@link android.view.View}. |
| <p>Related: <a href="#viewgroup">Viewgroup</a>, <a href="#widget">Widget |
| </a></p></dd> |
| |
| <dt id="viewgroup">Viewgroup</dt> |
| <dd> A container object that groups a set of child Views. The viewgroup is |
| responsible for deciding where child views are positioned and how large |
| they can be, as well as for calling each to draw itself when appropriate. |
| Some viewgroups are invisible and are for layout only, while others have |
| an intrinsic UI (for instance, a scrolling list box). Viewgroups are all |
| in the {@link android.widget widget} package, but extend |
| {@link android.view.ViewGroup ViewGroup}. |
| <p>Related: <a href="#view">View</a></p></dd> |
| |
| <dt id="widget">Widget</dt> |
| <dd>One of a set of fully implemented View subclasses that render form |
| elements and other UI components, such as a text box or popup menu. |
| Because a widget is fully implemented, it handles measuring and drawing |
| itself and responding to screen events. Widgets are all in the |
| {@link android.widget} package. </dd> |
| |
| <!-- |
| <dt id="panel">Panel</dt> |
| <dd> A panel is a concept not backed by a specific class. It is a View of |
| some sort that is tied in closely to a parent window, but can handle |
| clicks and perform simple functions related to its parent. A panel floats |
| in front of its parent, and is positioned relative to it. A common example |
| of a panel (implemented by Android) is the options menu available to every |
| screen. At present, there are no specific classes or methods for creating |
| a panel — it's more of a general idea. </dd> |
| --> |
| |
| <dt id="panel">Window</dt> |
| <dd>In an Android application, an object derived from the abstract class |
| {@link android.view.Window} that specifies the elements of a generic |
| window, such as the look and feel (title bar text, location and content of |
| menus, and so on). Dialog and Activity use an implementation of this class |
| to render a window. You do not need to implement this class or use windows |
| in your application. </dd> |
| |
| |
| </dl> |