TaskStackBuilder

public final class TaskStackBuilder
extends Object implements Iterable<Intent>

java.lang.Object
   ↳ androidx.core.app.TaskStackBuilder


Utility class for constructing synthetic back stacks for cross-task navigation on Android 3.0 and newer.

In API level 11 (Android 3.0/Honeycomb) the recommended conventions for app navigation using the back key changed. The back key's behavior is local to the current task and does not capture navigation across different tasks. Navigating across tasks and easily reaching the previous task is accomplished through the "recents" UI, accessible through the software-provided Recents key on the navigation or system bar. On devices with the older hardware button configuration the recents UI can be accessed with a long press on the Home key.

When crossing from one task stack to another post-Android 3.0, the application should synthesize a back stack/history for the new task so that the user may navigate out of the new task and back to the Launcher by repeated presses of the back key. Back key presses should not navigate across task stacks.

TaskStackBuilder provides a backward-compatible way to obey the correct conventions around cross-task navigation on the device's version of the platform. On devices running Android 3.0 or newer, calls to the startActivities() method or sending the PendingIntent generated by getPendingIntent(int, int) will construct the synthetic back stack as prescribed. On devices running older versions of the platform, these same calls will invoke the topmost activity in the supplied stack, ignoring the rest of the synthetic stack and allowing the back key to navigate back to the previous task.

About Navigation

For more detailed information about tasks, the back stack, and navigation design guidelines, please read Tasks and Back Stack from the developer guide and Navigation from the design guide.

Summary

Nested classes

interface TaskStackBuilder.SupportParentable

 

Public methods

TaskStackBuilder addNextIntent(Intent nextIntent)

Add a new Intent to the task stack.

TaskStackBuilder addNextIntentWithParentStack(Intent nextIntent)

Add a new Intent with the resolved chain of parents for the target activity to the task stack.

TaskStackBuilder addParentStack(ComponentName sourceActivityName)

Add the activity parent chain as specified by manifest <meta-data> elements to the task stack builder.

TaskStackBuilder addParentStack(Activity sourceActivity)

Add the activity parent chain as specified by manifest <meta-data> elements to the task stack builder.

TaskStackBuilder addParentStack(Class<?> sourceActivityClass)

Add the activity parent chain as specified by manifest <meta-data> elements to the task stack builder.

static TaskStackBuilder create(Context context)

Return a new TaskStackBuilder for launching a fresh task stack consisting of a series of activities.

Intent editIntentAt(int index)

Return the intent at the specified index for modification.

static TaskStackBuilder from(Context context)

This method is deprecated. use create(Context) instead

Intent getIntent(int index)

This method is deprecated. Renamed to editIntentAt to better reflect intended usage

int getIntentCount()
Intent[] getIntents()

Return an array containing the intents added to this builder.

PendingIntent getPendingIntent(int requestCode, int flags)

Obtain a PendingIntent for launching the task constructed by this builder so far.

PendingIntent getPendingIntent(int requestCode, int flags, Bundle options)

Obtain a PendingIntent for launching the task constructed by this builder so far.

Iterator<Intent> iterator()

This method is deprecated. Use editIntentAt instead

void startActivities()

Start the task stack constructed by this builder.

void startActivities(Bundle options)

Start the task stack constructed by this builder.

Inherited methods

Public methods

addNextIntent

public TaskStackBuilder addNextIntent (Intent nextIntent)

Add a new Intent to the task stack. The most recently added Intent will invoke the Activity at the top of the final task stack.

Parameters
nextIntent Intent: Intent for the next Activity in the synthesized task stack

Returns
TaskStackBuilder This TaskStackBuilder for method chaining

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