com.codetroopers.betterpickers

Class TouchExplorationHelper<T>

java.lang.Object

AccessibilityNodeProviderCompat

com.codetroopers.betterpickers.TouchExplorationHelper<T>

public abstract class TouchExplorationHelper<T>
extends AccessibilityNodeProviderCompat

Field Summary

Fields

Modifier and Type	Field and Description
static int	INVALID_ID Virtual node identifier value for invalid nodes.

Constructor Summary

Constructors

Constructor and Description
TouchExplorationHelper(android.content.Context context, android.view.View parentView) Constructs a new touch exploration helper.

Method Summary

Modifier and Type	Method and Description
void	clearFocusedItem() Clears the current accessibility focused item.
AccessibilityNodeInfoCompat	createAccessibilityNodeInfo(int virtualViewId)
AccessibilityDelegateCompat	getAccessibilityDelegate()
T	getFocusedItem()
protected abstract int	getIdForItem(T item) Returns the unique identifier for an item.
protected abstract T	getItemAt(float x, float y) Returns the item under the specified parent-relative coordinates.
protected abstract T	getItemForId(int id) Returns the item for a unique identifier.
protected abstract void	getVisibleItems(java.util.List<T> items) Populates a list with the parent view's visible items.
void	invalidateItem(T item) Invalidates cached information for a particular item.
void	invalidateParent() Invalidates cached information about the parent view.
boolean	performAction(int virtualViewId, int action, android.os.Bundle arguments)
protected abstract boolean	performActionForItem(T item, int action, android.os.Bundle arguments) Performs an accessibility action on the specified item.
protected abstract void	populateEventForItem(T item, android.view.accessibility.AccessibilityEvent event) Populates an event with information about the specified item.
protected abstract void	populateNodeForItem(T item, AccessibilityNodeInfoCompat node) Populates a node with information about the specified item.
boolean	sendEventForItem(T item, int eventType) Populates an event of the specified type with information about an item and attempts to send it up through the view hierarchy.
void	setFocusedItem(T item) Requests accessibility focus be placed on the specified item.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

INVALID_ID

public static final int INVALID_ID

Virtual node identifier value for invalid nodes.

See Also:

Constant Field Values

Constructor Detail

TouchExplorationHelper

public TouchExplorationHelper(android.content.Context context,
                              android.view.View parentView)

Constructs a new touch exploration helper.

Parameters:

context - The parent context.

Method Detail

getFocusedItem

public T getFocusedItem()

Returns:

The current accessibility focused item, or null if no item is focused.

clearFocusedItem

public void clearFocusedItem()

Clears the current accessibility focused item.

setFocusedItem

public void setFocusedItem(T item)

Requests accessibility focus be placed on the specified item.

Parameters:

item - The item to place focus on.

invalidateParent

public void invalidateParent()

Invalidates cached information about the parent view.

You must call this method after adding or removing items from the parent view.

invalidateItem

public void invalidateItem(T item)

Invalidates cached information for a particular item.

You must call this method when any of the properties set in populateNodeForItem(Object, AccessibilityNodeInfoCompat) have changed.

sendEventForItem

public boolean sendEventForItem(T item,
                                int eventType)

Populates an event of the specified type with information about an item and attempts to send it up through the view hierarchy.

Parameters:

item - The item for which to send an event.

eventType - The type of event to send.

Returns:

true if the event was sent successfully.

createAccessibilityNodeInfo

public AccessibilityNodeInfoCompat createAccessibilityNodeInfo(int virtualViewId)

performAction

public boolean performAction(int virtualViewId,
                             int action,
                             android.os.Bundle arguments)

getAccessibilityDelegate

public AccessibilityDelegateCompat getAccessibilityDelegate()

performActionForItem

protected abstract boolean performActionForItem(T item,
                                                int action,
                                                android.os.Bundle arguments)

Performs an accessibility action on the specified item. See AccessibilityNodeInfoCompat#performAction(int, android.os.Bundle).

The helper class automatically handles focus management resulting from AccessibilityNodeInfoCompat#ACTION_ACCESSIBILITY_FOCUS and AccessibilityNodeInfoCompat#ACTION_CLEAR_ACCESSIBILITY_FOCUS, so typically a developer only needs to handle actions added manually in the {populateNodeForItem(Object, AccessibilityNodeInfoCompat) method.

Parameters:

item - The item on which to perform the action.

action - The accessibility action to perform.

arguments - Arguments for the action, or optionally null.

Returns:

true if the action was performed successfully.

populateEventForItem

protected abstract void populateEventForItem(T item,
                                             android.view.accessibility.AccessibilityEvent event)

Populates an event with information about the specified item.

At a minimum, a developer must populate the event text by doing one of the following:

• appending text to AccessibilityRecord.getText()
• populating a description with AccessibilityRecord.setContentDescription(CharSequence)

Parameters:

item - The item for which to populate the event.

event - The event to populate.

populateNodeForItem

protected abstract void populateNodeForItem(T item,
                                            AccessibilityNodeInfoCompat node)

Populates a node with information about the specified item.

At a minimum, a developer must:

• populate the event text using AccessibilityNodeInfoCompat#setText(CharSequence) or AccessibilityNodeInfoCompat#setContentDescription(CharSequence)
• set the item's parent-relative bounds using AccessibilityNodeInfoCompat#setBoundsInParent(android.graphics.Rect)

Parameters:

item - The item for which to populate the node.

node - The node to populate.

getVisibleItems

protected abstract void getVisibleItems(java.util.List<T> items)

Populates a list with the parent view's visible items.

The result of this method is cached until the developer calls invalidateParent().

Parameters:

items - The list to populate with visible items.

getItemAt

protected abstract T getItemAt(float x,
                               float y)

Returns the item under the specified parent-relative coordinates.

Parameters:

x - The parent-relative x coordinate.

y - The parent-relative y coordinate.

Returns:

The item under coordinates (x,y).

getIdForItem

protected abstract int getIdForItem(T item)

Returns the unique identifier for an item. If the specified item does not exist, returns INVALID_ID.

This result of this method must be consistent with getItemForId(int).

Parameters:

item - The item whose identifier to return.

Returns:

A unique identifier, or INVALID_ID.

getItemForId

protected abstract T getItemForId(int id)

Returns the item for a unique identifier. If the specified item does not exist, returns null.

Parameters:

id - The identifier for the item to return.

Returns:

An item, or null.