1page.title=<activity> 2parent.title=The AndroidManifest.xml File 3parent.link=manifest-intro.html 4@jd:body 5 6<dl class="xml"> 7<dt>syntax:</dt> 8<dd><pre class="stx"><activity android:<a href="#reparent">allowTaskReparenting</a>=["true" | "false"] 9 android:<a href="#always">alwaysRetainTaskState</a>=["true" | "false"] 10 android:<a href="#clear">clearTaskOnLaunch</a>=["true" | "false"] 11 android:<a href="#config">configChanges</a>=["mcc", "mnc", "locale", 12 "touchscreen", "keyboard", "keyboardHidden", 13 "navigation", "screenLayout", "fontScale", "uiMode", 14 "orientation", "screenSize", "smallestScreenSize"] 15 android:<a href="#enabled">enabled</a>=["true" | "false"] 16 android:<a href="#exclude">excludeFromRecents</a>=["true" | "false"] 17 android:<a href="#exported">exported</a>=["true" | "false"] 18 android:<a href="#finish">finishOnTaskLaunch</a>=["true" | "false"] 19 android:<a href="#hwaccel">hardwareAccelerated</a>=["true" | "false"] 20 android:<a href="#icon">icon</a>="<i>drawable resource</i>" 21 android:<a href="#label">label</a>="<i>string resource</i>" 22 android:<a href="#lmode">launchMode</a>=["multiple" | "singleTop" | 23 "singleTask" | "singleInstance"] 24 android:<a href="#multi">multiprocess</a>=["true" | "false"] 25 android:<a href="#nm">name</a>="<i>string</i>" 26 android:<a href="#nohist">noHistory</a>=["true" | "false"] <!-- ##api level 3## --> 27 android:<a href="#parent">parentActivityName</a>="<i>string</i>" <!-- api level 16 --> 28 android:<a href="#prmsn">permission</a>="<i>string</i>" 29 android:<a href="#proc">process</a>="<i>string</i>" 30 android:<a href="#screen">screenOrientation</a>=["unspecified" | "user" | "behind" | 31 "landscape" | "portrait" | 32 "reverseLandscape" | "reversePortrait" | 33 "sensorLandscape" | "sensorPortrait" | 34 "sensor" | "fullSensor" | "nosensor"] 35 android:<a href="#state">stateNotNeeded</a>=["true" | "false"] 36 android:<a href="#aff">taskAffinity</a>="<i>string</i>" 37 android:<a href="#theme">theme</a>="<i>resource or theme</i>" 38 android:<a href="#uioptions">uiOptions</a>=["none" | "splitActionBarWhenNarrow"] 39 android:<a href="#wsoft">windowSoftInputMode</a>=["stateUnspecified", 40 "stateUnchanged", "stateHidden", 41 "stateAlwaysHidden", "stateVisible", 42 "stateAlwaysVisible", "adjustUnspecified", 43 "adjustResize", "adjustPan"] > <!-- ##api level 3## --> 44 . . . 45</activity></pre></dd> 46 47<dt>contained in:</dt> 48<dd><code><a href="{@docRoot}guide/topics/manifest/application-element.html"><application></a></code></dd> 49 50<dt>can contain:</dt> 51<dd><code><a href="{@docRoot}guide/topics/manifest/intent-filter-element.html"><intent-filter></a></code> 52<br/><code><a href="{@docRoot}guide/topics/manifest/meta-data-element.html"><meta-data></a></code></dd> 53 54<dt>description:</dt> 55<dd>Declares an activity (an {@link android.app.Activity} subclass) that 56implements part of the application's visual user interface. All activities 57must be represented by {@code <activity>} 58elements in the manifest file. Any that are not declared there will not be seen 59by the system and will never be run. 60 61<dt>attributes:</dt> 62<dd><dl class="attr"> 63<dt><a name="reparent"></a>{@code android:allowTaskReparenting}</dt> 64<dd>Whether or not the activity can move from the task that started it to 65the task it has an affinity for when that task is next brought to the 66front — "{@code true}" if it can move, and "{@code false}" if it 67must remain with the task where it started. 68 69<p> 70If this attribute is not set, the value set by the corresponding 71<code><a href="{@docRoot}guide/topics/manifest/application-element.html#reparent">allowTaskReparenting</a></code> 72attribute of the <code><a href="{@docRoot}guide/topics/manifest/application-element.html"><application></a></code> element 73applies to the activity. The default value is "{@code false}". 74</p> 75 76<p> 77Normally when an activity is started, it's associated with the task of 78the activity that started it and it stays there for its entire lifetime. 79You can use this attribute to force it to be re-parented to the task it 80has an affinity for when its current task is no longer displayed. 81Typically, it's used to cause the activities of an application to move 82to the main task associated with that application. 83</p> 84 85<p> 86For example, if an e-mail message contains a link to a web page, clicking 87the link brings up an activity that can display the page. That activity 88is defined by the browser application, but is launched as part of the e-mail 89task. If it's reparented to the browser task, it will be shown when the 90browser next comes to the front, and will be absent when the e-mail task 91again comes forward. 92</p> 93 94<p> 95The affinity of an activity is defined by the 96<code><a href="#aff">taskAffinity</a></code> attribute. The affinity 97of a task is determined by reading the affinity of its root activity. 98Therefore, by definition, a root activity is always in a task with the 99same affinity. Since activities with "{@code singleTask}" or 100"{@code singleInstance}" launch modes can only be at the root of a task, 101re-parenting is limited to the "{@code standard}" and "{@code singleTop}" 102modes. (See also the <code><a href="#lmode">launchMode</a></code> 103attribute.) 104</p></dd> 105 106<dt><a name="always"></a>{@code android:alwaysRetainTaskState}</dt> 107<dd>Whether or not the state of the task that the activity is in will always 108be maintained by the system — "{@code true}" if it will be, and 109"{@code false}" if the system is allowed to reset the task to its initial 110state in certain situations. The default value is "{@code false}". This 111attribute is meaningful only for the root activity of a task; it's ignored 112for all other activities. 113 114<p> 115Normally, the system clears a task (removes all activities from the stack 116above the root activity) in certain situations when the user re-selects that 117task from the home screen. Typically, this is done if the user hasn't visited 118the task for a certain amount of time, such as 30 minutes. 119</p> 120 121<p> 122However, when this attribute is "{@code true}", users will always return 123to the task in its last state, regardless of how they get there. This is 124useful, for example, in an application like the web browser where there is 125a lot of state (such as multiple open tabs) that users would not like to lose. 126</p></dd> 127 128<dt><a name="clear"></a>{@code android:clearTaskOnLaunch}</dt> 129<dd>Whether or not all activities will be removed from the task, except for 130the root activity, whenever it is re-launched from the home screen — 131"{@code true}" if the task is always stripped down to its root activity, and 132"{@code false}" if not. The default value is "{@code false}". This attribute 133is meaningful only for activities that start a new task (the root activity); 134it's ignored for all other activities in the task. 135 136<p> 137When the value is "{@code true}", every time users start the task again, they 138are brought to its root activity regardless of what they were last doing in 139the task and regardless of whether they used the <em>Back</em> or <em>Home</em> button to 140leave it. When the value is "{@code false}", the task may be cleared of activities in 141some situations (see the 142<code><a href="#always">alwaysRetainTaskState</a></code> attribute), but not always. 143</p> 144 145<p> 146Suppose, for example, that someone launches activity P from the home screen, 147and from there goes to activity Q. The user next presses <em>Home</em>, and then returns 148to activity P. Normally, the user would see activity Q, since that is what they 149were last doing in P's task. However, if P set this flag to "{@code true}", all 150of the activities on top of it (Q in this case) were removed when the user pressed 151<em>Home</em> and the task went to the background. So the user sees only P when returning 152to the task. 153</p> 154 155<p> 156If this attribute and <code><a href="#reparent">allowTaskReparenting</a></code> 157are both "{@code true}", any activities that can be re-parented are moved to 158the task they share an affinity with; the remaining activities are then dropped, 159as described above. 160</p></dd> 161 162<dt><a name="config"></a>{@code android:configChanges}</dt> 163<dd>Lists configuration changes that the activity will handle itself. When a configuration 164change occurs at runtime, the activity is shut down and restarted by default, but declaring a 165configuration with this attribute will prevent the activity from being restarted. Instead, the 166activity remains running and its <code>{@link android.app.Activity#onConfigurationChanged 167onConfigurationChanged()}</code> method is called. 168 169<p class="note"><strong>Note:</strong> Using this attribute should be 170avoided and used only as a last-resort. Please read <a 171href="{@docRoot}guide/topics/resources/runtime-changes.html">Handling Runtime Changes</a> for more 172information about how to properly handle a restart due to a configuration change.</p> 173 174<p> 175Any or all of the following strings are valid values for this attribute. Multiple values are 176separated by '{@code |}' — for example, "{@code locale|navigation|orientation}". 177</p> 178 179<table> 180<tr> 181 <th>Value</th> 182 <th>Description</th> 183</tr><tr> 184 <td>"{@code mcc}"</td> 185 <td>The IMSI mobile country code (MCC) has changed — 186 a SIM has been detected and updated the MCC.</td> 187</tr><tr> 188 <td>"{@code mnc}"</td> 189 <td>The IMSI mobile network code (MNC) has changed — 190 a SIM has been detected and updated the MNC.</td> 191</tr><tr> 192 <td>"{@code locale}"</td> 193 <td>The locale has changed — the user has selected a new 194 language that text should be displayed in.</td> 195</tr><tr> 196 <td>"{@code touchscreen}"</td> 197 <td>The touchscreen has changed. (This should never normally happen.)</td> 198</tr><tr> 199 <td>"{@code keyboard}"</td> 200 <td>The keyboard type has changed — for example, the user has 201 plugged in an external keyboard.</td> 202</tr><tr> 203 <td>"{@code keyboardHidden}"</td> 204 <td>The keyboard accessibility has changed — for example, the 205 user has revealed the hardware keyboard.</td> 206</tr><tr> 207 <td>"{@code navigation}"</td> 208 <td>The navigation type (trackball/dpad) has changed. (This should never normally happen.)</td> 209</tr><tr> 210 <td>"{@code screenLayout}"</td> 211 <td>The screen layout has changed — this might be caused by a 212 different display being activated.</td> 213 </tr><tr> 214 <td>"{@code fontScale}"</td> 215 <td>The font scaling factor has changed — the user has selected 216 a new global font size.</td> 217 </tr><tr> 218 <td>"{@code uiMode}"</td> 219 <td>The user interface mode has changed — this can be caused when the user places the 220device into a desk/car dock or when the the night mode changes. See {@link 221android.app.UiModeManager}. <em>Introduced in API Level 8</em>.</td> 222 </tr><tr> 223 <td>"{@code orientation}"</td> 224 <td>The screen orientation has changed — the user has rotated the device. 225 <p class="note"><strong>Note:</strong> If your application targets API level 13 or higher (as 226declared by the <a href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#min">{@code 227minSdkVersion}</a> and <a href="{@docRoot}guide/topics/manifest/uses-sdk-element.html#target">{@code 228targetSdkVersion}</a> attributes), then you should also declare the {@code "screenSize"} 229configuration, because it also changes when a device switches between portrait and landscape 230orientations.</p></td> 231 </tr><tr> 232 <td>"{@code screenSize}"</td> 233 <td>The current available screen size has changed. This represents a change in the currently 234available size, relative to the current aspect ratio, so will change when the user switches between 235landscape and portrait. However, if your application targets API level 12 or lower, then your 236activity always handles this configuration change itself (this configuration change does not restart 237your activity, even when running on an Android 3.2 or higher device). 238 <p><em>Added in API level 13.</em></p></td> 239 </tr><tr> 240 <td>"{@code smallestScreenSize}"</td> 241 <td>The physical screen size has changed. This represents a change in size regardless of 242orientation, so will only change when the actual physical screen size has changed such as switching 243to an external display. A change to this configuration corresponds to a change in the <a 244href="{@docRoot}guide/topics/resources/providing-resources.html#SmallestScreenWidthQualifier"> 245smallestWidth configuration</a>. However, if your application targets API level 12 or lower, then 246your activity always handles this configuration change itself (this configuration change does not 247restart your activity, even when running on an Android 3.2 or higher device). 248 <p><em>Added in API level 13.</em></p></td> 249 </tr> 250</table> 251 252<p> 253All of these configuration changes can impact the resource values seen by the 254application. Therefore, when <code>{@link android.app.Activity#onConfigurationChanged 255onConfigurationChanged()}</code> is called, it will generally be necessary to again 256retrieve all resources (including view layouts, drawables, and so on) to correctly 257handle the change. 258</p></dd> 259 260<dt><a name="enabled"></a>{@code android:enabled}</dt> 261<dd>Whether or not the activity can be instantiated by the system — 262"{@code true}" if it can be, and "{@code false}" if not. The default value 263is "{@code true}". 264 265<p> 266The <code><a href="{@docRoot}guide/topics/manifest/application-element.html"><application></a></code> element has its own 267<code><a href="{@docRoot}guide/topics/manifest/application-element.html#enabled">enabled</a></code> 268attribute that applies to all application components, including activities. The 269<code><a href="{@docRoot}guide/topics/manifest/application-element.html"><application></a></code> 270and {@code <activity>} attributes must both be "{@code true}" (as they both 271are by default) for the system to be able to instantiate the activity. If either 272is "{@code false}", it cannot be instantiated. 273</p></dd> 274 275<dt><a name="exclude"></a>{@code android:excludeFromRecents}</dt> 276<dd>Whether or not the task initiated by this activity should be excluded from the list of recently 277used applications ("recent apps"). That is, when this activity is the root activity of a new task, 278this attribute determines whether the task should not appear in the list of recent apps. "{@code 279true}" if the task should be <em>excluded</em> from the list; "{@code false}" if it should be 280<em>included</em>. The default value is "{@code false}". 281</p></dd> 282 283<dt><a name="exported"></a>{@code android:exported}</dt> 284<dd>Whether or not the activity can be launched by components of other 285applications — "{@code true}" if it can be, and "{@code false}" if not. 286If "{@code false}", the activity can be launched only by components of the 287same application or applications with the same user ID. 288 289<p> 290The default value depends on whether the activity contains intent filters. The 291absence of any filters means that the activity can be invoked only by specifying 292its exact class name. This implies that the activity is intended only for 293application-internal use (since others would not know the class name). So in 294this case, the default value is "{@code false}". 295On the other hand, the presence of at least one filter implies that the activity 296is intended for external use, so the default value is "{@code true}". 297</p> 298 299<p> 300This attribute is not the only way to limit an activity's exposure to other 301applications. You can also use a permission to limit the external entities that 302can invoke the activity (see the 303<code><a href="{@docRoot}guide/topics/manifest/activity-element.html#prmsn">permission</a></code> 304attribute). 305</p></dd> 306 307<dt><a name="finish"></a>{@code android:finishOnTaskLaunch}</dt> 308<dd>Whether or not an existing instance of the activity should be shut down 309(finished) whenever the user again launches its task (chooses the task on the 310home screen) — "{@code true}" if it should be shut down, and "{@code false}" 311if not. The default value is "{@code false}". 312 313<p> 314If this attribute and 315<code><a href="{@docRoot}guide/topics/manifest/activity-element.html#reparent">allowTaskReparenting</a></code> 316are both "{@code true}", this attribute trumps the other. The affinity of the 317activity is ignored. The activity is not re-parented, but destroyed. 318</p> 319 320<dt><a name="hwaccel"></a>{@code android:hardwareAccelerated}</dt> 321<dd>Whether or not hardware-accelerated rendering should be enabled for this 322Activity — "{@code true}" if it should be enabled, and "{@code false}" if 323not. The default value is "{@code false}". 324 325 326<p>Starting from Android 3.0, a hardware-accelerated OpenGL renderer is 327available to applications, to improve performance for many common 2D graphics 328operations. When the hardware-accelerated renderer is enabled, most operations 329in Canvas, Paint, Xfermode, ColorFilter, Shader, and Camera are accelerated. 330This results in smoother animations, smoother scrolling, and improved 331responsiveness overall, even for applications that do not explicitly make use 332the framework's OpenGL libraries. Because of the increased resources required to 333enable hardware acceleration, your app will consume more RAM.</p> 334 335<p>Note that not all of the OpenGL 2D operations are accelerated. If you enable 336the hardware-accelerated renderer, test your application to ensure that it can 337make use of the renderer without errors.</p> 338</dd> 339 340<dt><a name="icon"></a>{@code android:icon}</dt> 341<dd>An icon representing the activity. The icon is displayed to users when 342a representation of the activity is required on-screen. For example, icons 343for activities that initiate tasks are displayed in the launcher window. 344The icon is often accompanied by a label (see the <a href="#label">{@code 345android:label}</a> attribute). 346</p> 347 348<p> 349This attribute must be set as a reference to a drawable resource containing 350the image definition. If it is not set, the icon specified for the application 351as a whole is used instead (see the 352<code><a href="{@docRoot}guide/topics/manifest/application-element.html"><application></a></code> 353element's <code><a href="{@docRoot}guide/topics/manifest/application-element.html#icon">icon</a></code> attribute). 354</p> 355 356<p> 357The activity's icon — whether set here or by the 358<code><a href="{@docRoot}guide/topics/manifest/application-element.html"><application></a></code> 359element — is also the default icon for all the activity's intent filters (see the 360<code><a href="{@docRoot}guide/topics/manifest/intent-filter-element.html"><intent-filter></a></code> element's 361<code><a href="{@docRoot}guide/topics/manifest/intent-filter-element.html#icon">icon</a></code> attribute). 362</p></dd> 363 364<dt><a name="label"></a>{@code android:label}</dt> 365<dd>A user-readable label for the activity. The label is displayed on-screen 366when the activity must be represented to the user. It's often displayed along 367with the activity icon. 368 369<p> 370If this attribute is not set, the label set for the application as a whole is 371used instead (see the <code><a href="{@docRoot}guide/topics/manifest/application-element.html"><application></a></code> element's 372<code><a href="{@docRoot}guide/topics/manifest/application-element.html#label">label</a></code> attribute). 373</p> 374 375<p> 376The activity's label — whether set here or by the 377<code><a href="{@docRoot}guide/topics/manifest/application-element.html"><application></a></code> element — is also the 378default label for all the activity's intent filters (see the 379<code><a href="{@docRoot}guide/topics/manifest/intent-filter-element.html"><intent-filter></a></code> element's 380<code><a href="{@docRoot}guide/topics/manifest/intent-filter-element.html#label">label</a></code> attribute). 381</p> 382 383<p> 384The label should be set as a reference to a string resource, so that 385it can be localized like other strings in the user interface. 386However, as a convenience while you're developing the application, 387it can also be set as a raw string. 388</p></dd> 389 390<dt><a name="lmode"></a>{@code android:launchMode}</dt> 391<dd>An instruction on how the activity should be launched. There are four modes 392that work in conjunction with activity flags ({@code FLAG_ACTIVITY_*} constants) 393in {@link android.content.Intent} objects to determine what should happen when 394the activity is called upon to handle an intent. They are:</p> 395 396<p style="margin-left: 2em">"{@code standard}" 397<br>"{@code singleTop}" 398<br>"{@code singleTask}" 399<br>"{@code singleInstance}"</p> 400 401<p> 402The default mode is "{@code standard}". 403</p> 404 405<p> 406As shown in the table below, the modes fall into two main groups, with 407"{@code standard}" and "{@code singleTop}" activities on one side, and 408"{@code singleTask}" and "{@code singleInstance}" activities on the other. 409An activity with the "{@code standard}" or "{@code singleTop}" launch mode 410can be instantiated multiple times. The instances can belong to any task 411and can be located anywhere in the activity stack. Typically, they're 412launched into the task that called 413<code>{@link android.content.Context#startActivity startActivity()}</code> 414(unless the Intent object contains a 415<code>{@link android.content.Intent#FLAG_ACTIVITY_NEW_TASK}</code> 416instruction, in which case a different task is chosen — see the 417<a href="#aff">taskAffinity</a> attribute). 418</p> 419 420<p> 421In contrast, "<code>singleTask</code>" and "<code>singleInstance</code>" activities 422can only begin a task. They are always at the root of the activity stack. 423Moreover, the device can hold only one instance of the activity at a time 424— only one such task. 425</p> 426 427<p> 428The "{@code standard}" and "{@code singleTop}" modes differ from each other 429in just one respect: Every time there's a new intent for a "{@code standard}" 430activity, a new instance of the class is created to respond to that intent. 431Each instance handles a single intent. 432Similarly, a new instance of a "{@code singleTop}" activity may also be 433created to handle a new intent. However, if the target task already has an 434existing instance of the activity at the top of its stack, that instance 435will receive the new intent (in an 436<code>{@link android.app.Activity#onNewIntent onNewIntent()}</code> call); 437a new instance is not created. 438In other circumstances — for example, if an existing instance of the 439"{@code singleTop}" activity is in the target task, but not at the top of 440the stack, or if it's at the top of a stack, but not in the target task 441— a new instance would be created and pushed on the stack. 442</p> 443 444<p> 445The "{@code singleTask}" and "{@code singleInstance}" modes also differ from 446each other in only one respect: A "{@code singleTask}" activity allows other 447activities to be part of its task. It's always at the root of its task, but 448other activities (necessarily "{@code standard}" and "{@code singleTop}" 449activities) can be launched into that task. A "{@code singleInstance}" 450activity, on the other hand, permits no other activities to be part of its task. 451It's the only activity in the task. If it starts another activity, that 452activity is assigned to a different task — as if {@code 453FLAG_ACTIVITY_NEW_TASK} was in the intent. 454</p> 455 456<table> 457<tr> 458<th>Use Cases</th> 459<th>Launch Mode</th> 460<th>Multiple Instances?</th> 461<th>Comments</th> 462</tr> 463<tr> 464<td rowspan="2" style="width:20%;">Normal launches for most activities</td> 465<td>"<code>standard</code>"</td> 466<td>Yes</td> 467<td>Default. The system always creates a new instance of the activity in the 468target task and routes the intent to it.</td> 469</tr> 470<tr> 471<td>"<code>singleTop</code>"</td> 472<td>Conditionally</td> 473<td>If an instance of the activity already exists at the top of the target task, 474the system routes the intent to that instance through a call to its {@link 475android.app.Activity#onNewIntent onNewIntent()} method, rather than creating a 476new instance of the activity.</td> 477</tr> 478<tr> 479<td rowspan="2">Specialized launches<br> 480<em>(not recommended for general use)</em></td> 481<td>"<code>singleTask</code>"</td> 482<td>No</td> 483<td>The system creates the activity at the root of a new task and routes the 484intent to it. However, if an instance of the activity already exists, the system 485routes the intent to existing instance through a call to its {@link 486android.app.Activity#onNewIntent onNewIntent()} method, rather than creating a 487new one.</td> 488</tr> 489<tr> 490<td>"<code>singleInstance</code>"</td> 491<td>No</td> 492<td>Same as "<code>singleTask"</code>, except that the system doesn't launch any 493other activities into the task holding the instance. The activity is always the 494single and only member of its task.</td> 495</tr> 496</table> 497 498<p>As shown in the table above, <code>standard</code> is the default mode and is 499appropriate for most types of activities. <code>SingleTop</code> is also a 500common and useful launch mode for many types of activities. The other modes 501— <code>singleTask</code> and <code>singleInstance</code> — are 502<span style="color:red">not appropriate for most applications</span>, 503since they result in an interaction model that is likely to be unfamiliar to 504users and is very different from most other applications. 505 506<p>Regardless of the launch mode that you choose, make sure to test the usability 507of the activity during launch and when navigating back to it from 508other activities and tasks using the <em>Back</em> button. </p> 509 510<p>For more information on launch modes and their interaction with Intent 511flags, see the 512<a href="{@docRoot}guide/components/tasks-and-back-stack.html">Tasks and Back Stack</a> 513document. 514</p> 515</dd> 516 517<dt><a name="multi"></a>{@code android:multiprocess}</dt> 518<dd>Whether an instance of the activity can be launched into the process of the component 519that started it — "{@code true}" if it can be, and "{@code false}" if not. 520The default value is "{@code false}". 521 522<p> 523Normally, a new instance of an activity is launched into the process of the 524application that defined it, so all instances of the activity run in the same 525process. However, if this flag is set to "{@code true}", instances of the 526activity can run in multiple processes, allowing the system to create instances 527wherever they are used (provided permissions allow it), something that is almost 528never necessary or desirable. 529</p></dd> 530 531<dt><a name="nm"></a>{@code android:name}</dt> 532<dd>The name of the class that implements the activity, a subclass of 533{@link android.app.Activity}. The attribute value should be a fully qualified 534class name (such as, "{@code com.example.project.ExtracurricularActivity}"). 535However, as a shorthand, if the first character of the name is a period 536(for example, "{@code .ExtracurricularActivity}"), it is appended to the 537package name specified in the 538<code><a href="{@docRoot}guide/topics/manifest/manifest-element.html"><manifest></a></code> 539element. 540<p>Once you publish your application, you <a 541href="http://android-developers.blogspot.com/2011/06/things-that-cannot-change.html">should not 542change this name</a> (unless you've set <code><a 543href="#exported">android:exported</a>="false"</code>).</p> 544 545<p> 546There is no default. The name must be specified. 547</p></dd> 548 549<!-- ##api level 3## --> 550<dt><a name="nohist"></a>{@code android:noHistory}</dt> 551<dd>Whether or not the activity should be removed from the activity stack and 552finished (its <code>{@link android.app.Activity#finish finish()}</code> 553method called) when the user navigates away from it and it's no longer 554visible on screen — "{@code true}" if it should be finished, and 555"{@code false}" if not. The default value is "{@code false}". 556 557<p> 558A value of "{@code true}" means that the activity will not leave a 559historical trace. It will not remain in the activity stack for the task, 560so the user will not be able to return to it. 561</p> 562 563<p> 564This attribute was introduced in API Level 3. 565</p> 566</dd> 567 568<!-- api level 16 --> 569<dt><a name="parent"></a>{@code android:parentActivityName}</dt> 570<dd>The class name of the logical parent of the activity. The name here must be formatted 571 the same as the corresponding activity is declared in its own 572 <a href="#nm">android:name</a>. 573 574<p>The system reads this attribute to determine which activity should be started when 575 the use presses the Up button in the action bar. The system can also use this information to 576 synthesize a back stack of activities with {@link android.app.TaskStackBuilder}.</p> 577 578<p> 579This attribute was introduced in API Level 16. 580</p> 581</dd> 582 583 584 585<dt><a name="prmsn"></a>{@code android:permission}</dt> 586<dd>The name of a permission that clients must have to launch the activity 587or otherwise get it to respond to an intent. If a caller of 588<code>{@link android.content.Context#startActivity startActivity()}</code> or 589<code>{@link android.app.Activity#startActivityForResult startActivityForResult()}</code> 590has not been granted the specified permission, its intent will not be 591delivered to the activity. 592 593<p> 594If this attribute is not set, the permission set by the 595<code><a href="{@docRoot}guide/topics/manifest/application-element.html"><application></a></code> 596element's 597<code><a href="{@docRoot}guide/topics/manifest/application-element.html#prmsn">permission</a></code> 598attribute applies to the activity. If neither attribute is set, the activity is 599not protected by a permission. 600</p> 601 602<p> 603For more information on permissions, see the 604<a href="{@docRoot}guide/topics/manifest/manifest-intro.html#sectperm">Permissions</a> 605section in the introduction and another document, 606<a href="{@docRoot}guide/topics/security/security.html">Security and 607Permissions</a>. 608</p></dd> 609 610<dt><a name="proc"></a>{@code android:process}</dt> 611<dd>The name of the process in which the activity should run. Normally, 612all components of an application run in the default process created for the 613application. It has the same name as the application package. The <code><a href="{@docRoot}guide/topics/manifest/application-element.html"><application></a></code> element's 614<code><a href="{@docRoot}guide/topics/manifest/application-element.html#proc">process</a></code> 615attribute can set a different default for all components. But each component 616can override the default, allowing you to spread your application across 617multiple processes. 618 619<p> 620If the name assigned to this attribute begins with a colon (':'), a new 621process, private to the application, is created when it's needed and 622the activity runs in that process. 623If the process name begins with a lowercase character, the activity will run 624in a global process of that name, provided that it has permission to do so. 625This allows components in different applications to share a process, reducing 626resource usage. 627</p></dd> 628 629<dt><a name="screen"></a>{@code android:screenOrientation}</dt> 630<dd>The orientation of the activity's display on the device. 631 632<p>The value can be any one of the following strings:</p> 633 634<table> 635<tr> 636 <td>"{@code unspecified}"</td> 637 <td>The default value. The system chooses the orientation. The policy it 638 uses, and therefore the choices made in specific contexts, may differ 639 from device to device.</td> 640</tr><tr> 641 <td>"{@code user}"</td> 642 <td>The user's current preferred orientation.</td> 643</tr><tr> 644 <td>"{@code behind}"</td> 645 <td>The same orientation as the activity that's immediately beneath it in 646 the activity stack.</td> 647</tr><tr> 648 <td>"{@code landscape}"</td> 649 <td>Landscape orientation (the display is wider than it is tall).</td> 650</tr><tr> 651 <td>"{@code portrait}"</td> 652 <td>Portrait orientation (the display is taller than it is wide).</td> 653</tr><tr> 654 <td>"{@code reverseLandscape}"</td> 655 <td>Landscape orientation in the opposite direction from normal landscape. 656<em>Added in API level 9.</em></td> 657</tr><tr> 658 <td>"{@code reversePortrait}"</td> 659 <td>Portrait orientation in the opposite direction from normal portrait. 660<em>Added in API level 9.</em></td> 661</tr><tr> 662 <td>"{@code sensorLandscape}"</td> 663 <td>Landscape orientation, but can be either normal or reverse landscape based on the device 664sensor. 665<em>Added in API level 9.</em></td> 666</tr><tr> 667 <td>"{@code sensorPortrait}"</td> 668 <td>Portrait orientation, but can be either normal or reverse portrait based on the device 669sensor. 670<em>Added in API level 9.</em></td> 671</tr><tr> 672 <td>"{@code sensor}"</td> 673 <td>The orientation is determined by the device orientation sensor. The orientation of the 674display depends on how the user is holding the device; it changes when the user rotates the 675device. Some devices, though, will not rotate to all four possible orientations, by default. To 676allow all four orientations, use {@code "fullSensor"}.</td> 677</tr><tr> 678 <td>"{@code fullSensor}"</td> 679 <td>The orientation is determined by the device orientation sensor for any of the 4 orientations. 680This is similar to {@code "sensor"} except this allows any of the 4 possible screen orientations, 681regardless of what the device will normally do (for example, some devices won't normally use reverse 682portrait or reverse landscape, but this enables those). <em>Added in API level 9.</em></td> 683</tr><tr> 684 <td>"{@code nosensor}"</td> 685 <td>The orientation is determined without reference to a physical orientation sensor. The sensor 686is ignored, so the display will not rotate based on how the user moves the device. Except for this 687distinction, the system chooses the orientation using the same policy as for the "{@code 688unspecified}" setting.</td> 689</tr> 690</table> 691 692<p class="note"><strong>Note:</strong> When you declare one of the landscape or portrait values, 693it is considered a hard requirement for the orientation in which the activity runs. As such, 694the value you declare enables filtering by services such as Google Play so your application is 695available only to devices that support the orientation required by your activities. For 696example, if you declare either {@code "landscape"}, {@code "reverseLandscape"}, or 697{@code "sensorLandscape"}, then your application will be available only to devices that support 698landscape orientation. However, you should also explicitly declare that 699your application requires either portrait or landscape orientation with the <a 700href="{@docRoot}guide/topics/manifest/uses-feature-element.html">{@code <uses-feature>}</a> 701element. For example, <code><uses-feature 702android:name="android.hardware.screen.portrait"/></code>. This is purely a filtering behavior 703provided by Google Play (and other services that support it) and the platform itself does not 704control whether your app can be installed when a device supports only certain orientations.</p> 705 706</dd> 707 708<dt><a name="state"></a>{@code android:stateNotNeeded}</dt> 709<dd>Whether or not the activity can be killed and successfully restarted 710without having saved its state — "{@code true}" if it can be restarted 711without reference to its previous state, and "{@code false}" if its previous 712state is required. The default value is "{@code false}". 713 714<p> 715Normally, before an activity is temporarily shut down to save resources, its 716<code>{@link android.app.Activity#onSaveInstanceState onSaveInstanceState()}</code> 717method is called. This method stores the current state of the activity in a 718{@link android.os.Bundle} object, which is then passed to 719<code>{@link android.app.Activity#onCreate onCreate()}</code> when the activity 720is restarted. If this attribute is set to "{@code true}", 721{@code onSaveInstanceState()} may not be called and {@code onCreate()} will 722be passed {@code null} instead of the Bundle — just as it was when the 723activity started for the first time. 724</p> 725 726<p> 727A "{@code true}" setting ensures that the activity can be restarted in the 728absence of retained state. For example, the activity that displays the 729home screen uses this setting to make sure that it does not get removed if it 730crashes for some reason. 731</p></dd> 732 733<dt><a name="aff"></a>{@code android:taskAffinity}</dt> 734<dd>The task that the activity has an affinity for. Activities with 735the same affinity conceptually belong to the same task (to the same 736"application" from the user's perspective). The affinity of a task 737is determined by the affinity of its root activity. 738 739<p> 740The affinity determines two things — the task that the activity is re-parented 741to (see the <code><a href="{@docRoot}guide/topics/manifest/activity-element.html#reparent">allowTaskReparenting</a></code> 742attribute) and the task that will house the activity when it is launched 743with the <code>{@link android.content.Intent#FLAG_ACTIVITY_NEW_TASK}</code> 744flag. 745</p> 746 747<p> 748By default, all activities in an application have the same affinity. You 749can set this attribute to group them differently, and even place 750activities defined in different applications within the same task. To 751specify that the activity does not have an affinity for any task, set 752it to an empty string. 753 754<p> 755If this attribute is not set, the activity inherits the affinity set 756for the application (see the 757<code><a href="{@docRoot}guide/topics/manifest/application-element.html"><application></a></code> 758element's 759<code><a href="{@docRoot}guide/topics/manifest/application-element.html#aff">taskAffinity</a></code> 760attribute). The name of the default affinity for an application is 761the package name set by the 762<code><a href="{@docRoot}guide/topics/manifest/manifest-element.html"><manifest></a></code> 763element. 764</p> 765 766<dt><a name="theme"></a>{@code android:theme}</dt> 767<dd>A reference to a style resource defining an overall theme for the activity. 768This automatically sets the activity's context to use this theme (see 769<code>{@link android.content.Context#setTheme setTheme()}</code>, and may also 770cause "starting" animations prior to the activity being launched (to better 771match what the activity actually looks like). 772 773<p> 774If this attribute is not set, the activity inherits the theme set for the 775application as a whole — from the 776<code><a href="{@docRoot}guide/topics/manifest/application-element.html"><application></a></code> 777element's 778<code><a href="{@docRoot}guide/topics/manifest/application-element.html#theme">theme</a></code> 779attribute. If that attribute is also not set, the default system theme is used. For more 780information, see the <a 781href="{@docRoot}guide/topics/ui/themes.html">Styles and Themes</a> developer guide. 782</p> 783<dd> 784 785<!-- ##api level 14## --> 786<dt><a name="uioptions"></a>{@code android:uiOptions}</dt> 787<dd>Extra options for an activity's UI. 788 <p>Must be one of the following values.</p> 789 790 <table> 791 <tr><th>Value</th><th>Description</th></tr> 792 <tr><td>{@code "none"}</td><td>No extra UI options. This is the default.</td></tr> 793 <tr><td>{@code "splitActionBarWhenNarrow"}</td><td>Add a bar at 794the bottom of the screen to display action items in the {@link android.app.ActionBar}, when 795constrained for horizontal space (such as when in portrait mode on a handset). Instead of a small 796number of action items appearing in the action bar at the top of the screen, the action bar is 797split into the top navigation section and the bottom bar for action items. This ensures a reasonable 798amount of space is made available not only for the action items, but also for navigation and title 799elements at the top. Menu items are not split across the two bars; they always appear 800together.</td></tr> 801 </table> 802 <p>For more information about the action bar, see the <a 803href="{@docRoot}guide/topics/ui/actionbar.html">Action Bar</a> developer guide.</p> 804 <p>This attribute was added in API level 14.</p> 805</dd> 806 807 808<!-- ##api level 3## --> 809<dt><a name="wsoft"></a>{@code android:windowSoftInputMode}</dt> 810<dd>How the main window of the activity interacts with the window containing 811the on-screen soft keyboard. The setting for this attribute affects two 812things: 813 814<ul> 815<li>The state of the soft keyboard — whether it is hidden or visible 816— when the activity becomes the focus of user attention.</li> 817 818<li>The adjustment made to the activity's main window — whether it is 819resized smaller to make room for the soft keyboard or whether its contents 820pan to make the current focus visible when part of the window is covered by 821the soft keyboard.</li> 822</ul> 823 824<p> 825The setting must be one of the values listed in the following table, or a 826combination of one "{@code state...}" value plus one "{@code adjust...}" 827value. Setting multiple values in either group — multiple 828"{@code state...}" values, for example — has undefined results. 829Individual values are separated by a vertical bar ({@code |}). For example: 830</p> 831 832<pre><activity android:windowSoftInputMode="stateVisible|adjustResize" . . . ></pre> 833 834<p> 835Values set here (other than "{@code stateUnspecified}" and 836"{@code adjustUnspecified}") override values set in the theme. 837</p> 838 839<table> 840<tr> 841 <th>Value</th> 842 <th>Description</th> 843</tr><tr> 844 <td>"{@code stateUnspecified}"</td> 845 <td>The state of the soft keyboard (whether it is hidden or visible) 846 is not specified. The system will choose an appropriate state or 847 rely on the setting in the theme. 848 849 <p> 850 This is the default setting for the behavior of the soft keyboard. 851 </p></td> 852</tr></tr> 853 <td>"{@code stateUnchanged}"</td> 854 <td>The soft keyboard is kept in whatever state it was last in, 855 whether visible or hidden, when the activity comes to the fore.</td> 856</tr></tr> 857 <td>"{@code stateHidden}"</td> 858 <td>The soft keyboard is hidden when the user chooses the activity 859 — that is, when the user affirmatively navigates forward to the 860 activity, rather than backs into it because of leaving another activity.</td> 861</tr></tr> 862 <td>"{@code stateAlwaysHidden}"</td> 863 <td>The soft keyboard is always hidden when the activity's main window 864 has input focus.</td> 865</tr></tr> 866 <td>"{@code stateVisible}"</td> 867 <td>The soft keyboard is visible when that's normally appropriate 868 (when the user is navigating forward to the activity's main window).</td> 869</tr></tr> 870 <td>"{@code stateAlwaysVisible}"</td> 871 <td>The soft keyboard is made visible when the user chooses the 872 activity — that is, when the user affirmatively navigates forward 873 to the activity, rather than backs into it because of leaving another 874 activity.</td> 875</tr></tr> 876 <td>"{@code adjustUnspecified}"</td> 877 <td>It is unspecified whether the activity's main window resizes 878 to make room for the soft keyboard, or whether the contents 879 of the window pan to make the currentfocus visible on-screen. 880 The system will automatically select one of these modes depending 881 on whether the content of the window has any layout views that 882 can scroll their contents. If there is such a view, the window 883 will be resized, on the assumption that scrolling can make all 884 of the window's contents visible within a smaller area. 885 886 <p> 887 This is the default setting for the behavior of the main window. 888 </p></td> 889</tr></tr> 890 <td>"{@code adjustResize}"</td> 891 <td>The activity's main window is always resized to make room for 892 the soft keyboard on screen.</td> 893</tr></tr> 894 <td>"{@code adjustPan}"</td> 895 <td>The activity's main window is not resized to make room for the soft 896 keyboard. Rather, the contents of the window are automatically 897 panned so that the current focus is never obscured by the keyboard 898 and users can always see what they are typing. This is generally less 899 desirable than resizing, because the user may need to close the soft 900 keyboard to get at and interact with obscured parts of the window.</td> 901</tr> 902</table> 903 904<p> 905This attribute was introduced in API Level 3. 906</p></dd> 907</dl></dd> 908 909<!-- ##api level indication## --> 910<dt>introduced in:</dt> 911<dd>API Level 1 for all attributes except for 912<code><a href="#nohist">noHistory</a></code> and 913<code><a href="#wsoft">windowSoftInputMode</a></code>, which were added in API 914Level 3.</dd> 915 916<dt>see also:</dt> 917<dd><code><a href="{@docRoot}guide/topics/manifest/application-element.html"><application></a></code> 918<br/><code><a href="{@docRoot}guide/topics/manifest/activity-alias-element.html"><activity-alias></a></code></dd> 919</dl> 920