ContentCaptureSession

VERSION_1

static val VERSION_1: Int

Content Capture Version 1.

The first Content Capture version is an information rich, event based system that attempts to transfer the current view hierarchy from the application process to a system intelligence service through periodic event dumps, e.g. flush(). However, this system can also be resource heavy due to the large number of events it generates.

When this version is returned by getContentCaptureVersion(), developers should use Version 1 APIs to notify the system of view hierarchy changes. Calling Version 2 APIs when the session is configured for Version 1 will result in no-ops.

A list of functions that belong explicitly to Content Capture Version 1:

• notifyViewAppeared(ViewStructure)
• notifyViewDisappeared(AutofillId)
• notifyViewsAppeared(List)
• notifyViewsDisappeared(AutofillId,long[])
• notifyViewTextChanged(AutofillId,CharSequence)
• flush()
• newViewStructure(View)
• newVirtualViewStructure(AutofillId,long)

Value: 1

VERSION_2

static val VERSION_2: Int

Content Capture Version 2.

The second and newer Content Capture takes a more focused and leaner approach to passing the view hierarchy from the application to a system intelligence service. The required information is mostly limited to text on screen and bounding boxes of these text nodes. This version of Content Capture is also significantly more efficient at resource usage and recommended to be the default one for various system intelligence services to use.

When this version is returned by getContentCaptureVersion(), developers should use Version 2 APIs to report node lifecycle and property updates. Calling Version 1 APIs when the session is configured for Version 2 will result in no-ops.

A list of functions that belong explicitly to Content Capture Version 2:

• notifyNodeAppearedOrChanged(AutofillId,ContentCaptureNodeProperties)
• notifyNodeDisappeared(AutofillId)

Value: 2

close

open fun close(): Unit

Closes this resource, relinquishing any underlying resources. This method is invoked automatically on objects managed by the try-with-resources statement.

createContentCaptureSession

fun createContentCaptureSession(context: ContentCaptureContext): ContentCaptureSession

Creates a new ContentCaptureSession.

See View.setContentCaptureSession(ContentCaptureSession) for more info.

destroy

fun destroy(): Unit

Destroys this session, flushing out all pending notifications to the service.

Once destroyed, any new notification will be dropped.

flush

open fun flush(): Unit

Flushes an internal buffer of UI events and signals System Intelligence (SI) that a semantically meaningful state has been reached. SI uses this signal to potentially rebuild the view hierarchy and understand the current state of the UI.

UI events are often batched together for performance reasons. A semantic batch represents a series of events that, when applied sequentially, result in a meaningful and complete UI state.

It is crucial to call flush() after completing a semantic batch to ensure SI can accurately reconstruct the view hierarchy.

Premature Flushing: Calling flush() within a semantic batch may lead to SI failing to rebuild the view hierarchy correctly. This could manifest as incorrect ordering of sibling nodes.

Delayed Flushing: While not immediately flushing after a semantic batch is generally safe, it's recommended to do so as soon as possible. In the worst-case scenario where a flush() is never called, SI will attempt to process the events after a short delay based on view appearance and disappearance events.

Note; This function belongs to Content Capture Version 1.

getContentCaptureContext

fun getContentCaptureContext(): ContentCaptureContext?

Gets the ContentCaptureContext associated with the session.

getContentCaptureSessionId

fun getContentCaptureSessionId(): ContentCaptureSessionId

Gets the id used to identify this session.

getContentCaptureVersion

abstract fun getContentCaptureVersion(): Int

Gets the Content Capture version enabled for this session.

ContentCaptureSession offers two versions: VERSION_1 (legacy event-based capture using ViewStructure) and VERSION_2 (leaner, buffer-backed capture focused on text and bounding boxes).

The returned version is decided by the system intelligence service that coordinates this ContentCaptureSession.

newAutofillId

open fun newAutofillId(
    hostId: AutofillId, 
    virtualChildId: Long
): AutofillId

Creates a new AutofillId for a virtual child, so it can be used to uniquely identify the children in the session.

newViewStructure

fun newViewStructure(view: View): ViewStructure

Creates a ViewStructure for a "standard" view.

This method should be called after a visible view is laid out; the view then must populate the structure and pass it to notifyViewAppeared(ViewStructure). Note: views that manage a virtual structure under this view must populate just the node representing this view and return right away, then asynchronously report (not necessarily in the UI thread) when the children nodes appear, disappear or have their text changed by calling ContentCaptureSession.notifyViewAppeared(ViewStructure), ContentCaptureSession.notifyViewDisappeared(AutofillId), and ContentCaptureSession.notifyViewTextChanged(AutofillId,CharSequence) respectively. The structure for the a child must be created using ContentCaptureSession.newVirtualViewStructure(AutofillId,long), and the autofillId for a child can be obtained either through childStructure.getAutofillId() or ContentCaptureSession.newAutofillId(AutofillId,long).

When the virtual view hierarchy represents a web page, you should also:

• Call ContentCaptureManager.getContentCaptureConditions() to infer content capture events should be generate for that URL.
• Create a new ContentCaptureSession child for every HTML element that renders a new URL (like an IFRAME) and use that session to notify events from that subtree.

Note: the following methods of the structure will be ignored:

• ViewStructure.setChildCount(int)
• ViewStructure.addChildCount(int)
• ViewStructure.getChildCount()
• ViewStructure.newChild(int)
• ViewStructure.asyncNewChild(int)
• ViewStructure.asyncCommit()
• ViewStructure.setWebDomain(String)
• ViewStructure.newHtmlInfoBuilder(String)
• ViewStructure.setHtmlInfo(android.view.ViewStructure.HtmlInfo)
• ViewStructure.setDataIsSensitive(boolean)
• ViewStructure.setAlpha(float)
• ViewStructure.setElevation(float)
• ViewStructure.setTransformation(android.graphics.Matrix)

Note: This function belongs to Content Capture Version 1.

newVirtualViewStructure

fun newVirtualViewStructure(
    parentId: AutofillId, 
    virtualId: Long
): ViewStructure

Creates a ViewStructure for a "virtual" view, so it can be passed to notifyViewAppeared(ViewStructure) by the view managing the virtual view hierarchy.

Note: This function belongs to Content Capture Version 1.

notifyContentInteractionEvent

open fun notifyContentInteractionEvent(autofillId: AutofillId): Unit

Notifies the Intelligence Service that a view has been interacted.

The view must have appeared before sending the interaction event.

notifyNodeAppearedOrChanged

abstract fun notifyNodeAppearedOrChanged(
    id: AutofillId, 
    properties: ContentCaptureNodeProperties?
): Unit

Creates a new node or updates an existing one according to the changes in properties.

This is the primary method to construct and report the UI hierarchy in Content Capture Version 2. It unifies the reporting of both standard Views and virtual views (e.g., inside a Webview) into a single, cohesive API. Call this method when a node is attached, laid out, and ready to be drawn in the active UI hierarchy, or when its properties (like text or bounds) change.

For standard views, the id can be obtained via View.getAutofillId(). For virtual views, the id must be created using newAutofillId(AutofillId,long).

To minimize memory allocations, applications should reuse a single ContentCaptureNodeProperties instance, calling ContentCaptureNodeProperties.clear() before populating it for a new node.

If the node already exists, only the properties explicitly set in the ContentCaptureNodeProperties payload will be updated. The parent-child relationship is modified based on the parent ID configuration:

• Setting parent ID to null: Guarantees that this node is treated as a root node with no parent.
• Not setting parent ID at all: Leaves the existing parent unchanged. If the node is appearing for the first time, it defaults to a root node.

Note: This function belongs to Content Capture Version 2.

notifyNodeDisappeared

abstract fun notifyNodeDisappeared(id: AutofillId): Unit

Removes a node from the active content capture hierarchy.

This is the primary method to report the removal of UI components in Content Capture Version 2. It applies to both standard Views and virtual views, signaling that the node is no longer part of the visible hierarchy.

When a node is deleted:

• Its internal resources (such as text and content description allocations) are freed.
• Its children are orphaned and promoted to root nodes (their parent pointer is cleared). If you want to remove an entire subtree, you must recursively call this method for all descendant nodes in the subtree. Re-adding this node will not automatically relink previous children.

Note; This function belongs to Content Capture Version 2.

notifySessionPaused

fun notifySessionPaused(): Unit

Notifies the Content Capture Service that a session has paused.

notifySessionResumed

fun notifySessionResumed(): Unit

Notifies the Content Capture Service that a session has resumed.

notifyViewAppeared

fun notifyViewAppeared(node: ViewStructure): Unit

Notifies the Content Capture Service that a node has been added to the view structure.

Typically called "manually" by views that handle their own virtual view hierarchy, or automatically by the Android System for views that return true on View.onProvideContentCaptureStructure(ViewStructure,int).

Consider use notifyViewsAppeared which has a better performance when notifying a list of nodes has appeared.

Note; This function belongs to Content Capture Version 1.

notifyViewDisappeared

fun notifyViewDisappeared(id: AutofillId): Unit

Notifies the Content Capture Service that a node has been removed from the view structure.

Typically called "manually" by views that handle their own virtual view hierarchy, or automatically by the Android System for standard views.

Consider use notifyViewsDisappeared which has a better performance when notifying a list of nodes has disappeared.

Note; This function belongs to Content Capture Version 1.

notifyViewInsetsChanged

fun notifyViewInsetsChanged(viewInsets: Insets): Unit

Notifies the Intelligence Service that the insets of a view have changed.

notifyViewTextChanged

fun notifyViewTextChanged(
    id: AutofillId, 
    text: CharSequence?
): Unit

Notifies the Intelligence Service that the value of a text node has been changed.

Note; This function belongs to Content Capture Version 1.

notifyViewsAppeared

fun notifyViewsAppeared(appearedNodes: MutableList<ViewStructure!>): Unit

Notifies the Content Capture Service that a list of nodes has appeared in the view structure.

Typically called manually by views that handle their own virtual view hierarchy.

Note; This function belongs to Content Capture Version 1.

notifyViewsDisappeared

fun notifyViewsDisappeared(
    hostId: AutofillId, 
    virtualIds: LongArray
): Unit

Notifies the Content Capture Service that many nodes has been removed from a virtual view structure.

Should only be called by views that handle their own virtual view hierarchy.

After UPSIDE_DOWN_CAKE, this method wraps the virtual children with a pair of view tree appearing and view tree appeared events.

Note; This function belongs to Content Capture Version 1.

setContentCaptureContext

fun setContentCaptureContext(context: ContentCaptureContext?): Unit

Sets the ContentCaptureContext associated with the session.

Typically used to change the context associated with the default session from an activity.

toString

open fun toString(): String

Returns a string representation of the object.