/*
* Copyright 2019 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package androidx.compose.ui.semantics
import androidx.compose.runtime.Immutable
import androidx.compose.ui.ExperimentalComposeUiApi
import androidx.compose.ui.state.ToggleableState
import androidx.compose.ui.text.AnnotatedString
import androidx.compose.ui.text.TextLayoutResult
import androidx.compose.ui.text.TextRange
import androidx.compose.ui.text.input.ImeAction
import kotlin.reflect.KProperty
/**
* General semantics properties, mainly used for accessibility and testing.
*
* Each of these is intended to be set by the respective SemanticsPropertyReceiver extension
* instead of used directly.
*/
/*@VisibleForTesting*/
object SemanticsProperties {
/**
* @see SemanticsPropertyReceiver.contentDescription
*/
val ContentDescription = SemanticsPropertyKey<List<String>>(
name = "ContentDescription",
mergePolicy = { parentValue, childValue ->
parentValue?.toMutableList()?.also { it.addAll(childValue) } ?: childValue
}
)
/**
* @see SemanticsPropertyReceiver.stateDescription
*/
val StateDescription = SemanticsPropertyKey<String>("StateDescription")
/**
* @see SemanticsPropertyReceiver.progressBarRangeInfo
*/
val ProgressBarRangeInfo =
SemanticsPropertyKey<ProgressBarRangeInfo>("ProgressBarRangeInfo")
/**
* @see SemanticsPropertyReceiver.paneTitle
*/
val PaneTitle = SemanticsPropertyKey<String>(
name = "PaneTitle",
mergePolicy = { _, _ ->
throw IllegalStateException(
"merge function called on unmergeable property PaneTitle."
)
}
)
/** @see SemanticsPropertyReceiver.selectableGroup */
val SelectableGroup = SemanticsPropertyKey<Unit>("SelectableGroup")
/** @see SemanticsPropertyReceiver.collectionInfo */
val CollectionInfo = SemanticsPropertyKey<CollectionInfo>("CollectionInfo")
/** @see SemanticsPropertyReceiver.collectionItemInfo */
val CollectionItemInfo = SemanticsPropertyKey<CollectionItemInfo>("CollectionItemInfo")
/**
* @see SemanticsPropertyReceiver.heading
*/
val Heading = SemanticsPropertyKey<Unit>("Heading")
/**
* @see SemanticsPropertyReceiver.disabled
*/
val Disabled = SemanticsPropertyKey<Unit>("Disabled")
/**
* @see SemanticsPropertyReceiver.liveRegion
*/
val LiveRegion = SemanticsPropertyKey<LiveRegionMode>("LiveRegion")
/**
* @see SemanticsPropertyReceiver.focused
*/
val Focused = SemanticsPropertyKey<Boolean>("Focused")
/**
* @see SemanticsPropertyReceiver.invisibleToUser
*/
@ExperimentalComposeUiApi
val InvisibleToUser = SemanticsPropertyKey<Unit>(
name = "InvisibleToUser",
mergePolicy = { parentValue, _ ->
parentValue
}
)
/**
* @see SemanticsPropertyReceiver.horizontalScrollAxisRange
*/
val HorizontalScrollAxisRange =
SemanticsPropertyKey<ScrollAxisRange>("HorizontalScrollAxisRange")
/**
* @see SemanticsPropertyReceiver.verticalScrollAxisRange
*/
val VerticalScrollAxisRange =
SemanticsPropertyKey<ScrollAxisRange>("VerticalScrollAxisRange")
/**
* @see SemanticsPropertyReceiver.popup
*/
val IsPopup = SemanticsPropertyKey<Unit>(
name = "IsPopup",
mergePolicy = { _, _ ->
throw IllegalStateException(
"merge function called on unmergeable property IsPopup. " +
"A popup should not be a child of a clickable/focusable node."
)
}
)
/**
* @see SemanticsPropertyReceiver.dialog
*/
val IsDialog = SemanticsPropertyKey<Unit>(
name = "IsDialog",
mergePolicy = { _, _ ->
throw IllegalStateException(
"merge function called on unmergeable property IsDialog. " +
"A dialog should not be a child of a clickable/focusable node."
)
}
)
/**
* The type of user interface element. Accessibility services might use this to describe the
* element or do customizations. Most roles can be automatically resolved by the semantics
* properties of this element. But some elements with subtle differences need an exact role. If
* an exact role is not listed in [Role], this property should not be set and the framework will
* automatically resolve it.
*
* @see SemanticsPropertyReceiver.role
*/
val Role = SemanticsPropertyKey<Role>("Role") { parentValue, _ -> parentValue }
/**
* @see SemanticsPropertyReceiver.testTag
*/
val TestTag = SemanticsPropertyKey<String>(
name = "TestTag",
mergePolicy = { parentValue, _ ->
// Never merge TestTags, to avoid leaking internal test tags to parents.
parentValue
}
)
/**
* @see SemanticsPropertyReceiver.text
*/
val Text = SemanticsPropertyKey<List<AnnotatedString>>(
name = "Text",
mergePolicy = { parentValue, childValue ->
parentValue?.toMutableList()?.also { it.addAll(childValue) } ?: childValue
}
)
/**
* @see SemanticsPropertyReceiver.editableText
*/
val EditableText = SemanticsPropertyKey<AnnotatedString>(name = "EditableText")
/**
* @see SemanticsPropertyReceiver.textSelectionRange
*/
val TextSelectionRange = SemanticsPropertyKey<TextRange>("TextSelectionRange")
/**
* @see SemanticsPropertyReceiver.imeAction
*/
val ImeAction = SemanticsPropertyKey<ImeAction>("ImeAction")
/**
* @see SemanticsPropertyReceiver.selected
*/
val Selected = SemanticsPropertyKey<Boolean>("Selected")
/**
* @see SemanticsPropertyReceiver.toggleableState
*/
val ToggleableState = SemanticsPropertyKey<ToggleableState>("ToggleableState")
/**
* @see SemanticsPropertyReceiver.password
*/
val Password = SemanticsPropertyKey<Unit>("Password")
/**
* @see SemanticsPropertyReceiver.error
*/
val Error = SemanticsPropertyKey<String>("Error")
/**
* @see SemanticsPropertyReceiver.indexForKey
*/
val IndexForKey = SemanticsPropertyKey<(Any) -> Int>("IndexForKey")
}
/**
* Ths object defines keys of the actions which can be set in semantics and performed on the
* semantics node.
*
* Each of these is intended to be set by the respective SemanticsPropertyReceiver extension
* instead of used directly.
*/
/*@VisibleForTesting*/
object SemanticsActions {
/**
* @see SemanticsPropertyReceiver.getTextLayoutResult
*/
val GetTextLayoutResult =
ActionPropertyKey<(MutableList<TextLayoutResult>) -> Boolean>("GetTextLayoutResult")
/**
* @see SemanticsPropertyReceiver.onClick
*/
val OnClick = ActionPropertyKey<() -> Boolean>("OnClick")
/**
* @see SemanticsPropertyReceiver.onLongClick
*/
val OnLongClick = ActionPropertyKey<() -> Boolean>("OnLongClick")
/**
* @see SemanticsPropertyReceiver.scrollBy
*/
val ScrollBy = ActionPropertyKey<(x: Float, y: Float) -> Boolean>("ScrollBy")
/**
* @see SemanticsPropertyReceiver.scrollToIndex
*/
val ScrollToIndex = ActionPropertyKey<(Int) -> Boolean>("ScrollToIndex")
/**
* @see SemanticsPropertyReceiver.setProgress
*/
val SetProgress = ActionPropertyKey<(progress: Float) -> Boolean>("SetProgress")
/**
* @see SemanticsPropertyReceiver.setSelection
*/
val SetSelection = ActionPropertyKey<(Int, Int, Boolean) -> Boolean>("SetSelection")
/**
* @see SemanticsPropertyReceiver.setText
*/
val SetText = ActionPropertyKey<(AnnotatedString) -> Boolean>("SetText")
/**
* @see SemanticsPropertyReceiver.copyText
*/
val CopyText = ActionPropertyKey<() -> Boolean>("CopyText")
/**
* @see SemanticsPropertyReceiver.cutText
*/
val CutText = ActionPropertyKey<() -> Boolean>("CutText")
/**
* @see SemanticsPropertyReceiver.pasteText
*/
val PasteText = ActionPropertyKey<() -> Boolean>("PasteText")
/**
* @see SemanticsPropertyReceiver.expand
*/
val Expand = ActionPropertyKey<() -> Boolean>("Expand")
/**
* @see SemanticsPropertyReceiver.collapse
*/
val Collapse = ActionPropertyKey<() -> Boolean>("Collapse")
/**
* @see SemanticsPropertyReceiver.dismiss
*/
val Dismiss = ActionPropertyKey<() -> Boolean>("Dismiss")
/**
* @see SemanticsPropertyReceiver.customActions
*/
val CustomActions =
SemanticsPropertyKey<List<CustomAccessibilityAction>>("CustomActions")
}
/**
* SemanticsPropertyKey is the infrastructure for setting key/value pairs inside semantics blocks
* in a type-safe way. Each key has one particular statically defined value type T.
*/
class SemanticsPropertyKey<T>(
/**
* The name of the property. Should be the same as the constant from which it is accessed.
*/
val name: String,
internal val mergePolicy: (T?, T) -> T? = { parentValue, childValue ->
parentValue ?: childValue
}
) {
/**
* Method implementing the semantics merge policy of a particular key.
*
* When mergeDescendants is set on a semantics node, then this function will called for each
* descendant node of a given key in depth-first-search order. The parent
* value accumulates the result of merging the values seen so far, similar to reduce().
*
* The default implementation returns the parent value if one exists, otherwise uses the
* child element. This means by default, a SemanticsNode with mergeDescendants = true
* winds up with the first value found for each key in its subtree in depth-first-search order.
*/
fun merge(parentValue: T?, childValue: T): T? {
return mergePolicy(parentValue, childValue)
}
/**
* Throws [UnsupportedOperationException]. Should not be called.
*/
// TODO(KT-6519): Remove this getter
// TODO(KT-32770): Cannot deprecate this either as the getter is considered called by "by"
final operator fun getValue(thisRef: SemanticsPropertyReceiver, property: KProperty<*>): T {
return throwSemanticsGetNotSupported()
}
final operator fun setValue(
thisRef: SemanticsPropertyReceiver,
property: KProperty<*>,
value: T
) {
thisRef[this] = value
}
override fun toString(): String {
return "SemanticsPropertyKey: $name"
}
}
private fun <T> throwSemanticsGetNotSupported(): T {
throw UnsupportedOperationException(
"You cannot retrieve a semantics property directly - " +
"use one of the SemanticsConfiguration.getOr* methods instead"
)
}
/**
* Standard accessibility action.
*
* @param label The description of this action
* @param action The function to invoke when this action is performed. The function should return
* a boolean result indicating whether the action is successfully handled. For example, a scroll
* forward action should return false if the widget is not enabled or has reached the end of the
* list. If multiple semantics blocks with the same AccessibilityAction are provided, the
* resulting AccessibilityAction's label/action will be the label/action of the outermost
* modifier with this key and nonnull label/action, or null if no nonnull label/action is found.
*/
class AccessibilityAction<T : Function<Boolean>>(val label: String?, val action: T?) {
override fun equals(other: Any?): Boolean {
if (this === other) return true
if (other !is AccessibilityAction<*>) return false
if (label != other.label) return false
if (action != other.action) return false
return true
}
override fun hashCode(): Int {
var result = label?.hashCode() ?: 0
result = 31 * result + action.hashCode()
return result
}
override fun toString(): String {
return "AccessibilityAction(label=$label, action=$action)"
}
}
@Suppress("NOTHING_TO_INLINE")
// inline to break static initialization cycle issue
private inline fun <T : Function<Boolean>> ActionPropertyKey(
name: String
): SemanticsPropertyKey<AccessibilityAction<T>> {
return SemanticsPropertyKey(
name = name,
mergePolicy = { parentValue, childValue ->
AccessibilityAction(
parentValue?.label ?: childValue.label,
parentValue?.action ?: childValue.action
)
}
)
}
/**
* Custom accessibility action.
*
* @param label The description of this action
* @param action The function to invoke when this action is performed. The function should have no
* arguments and return a boolean result indicating whether the action is successfully handled.
*/
class CustomAccessibilityAction(val label: String, val action: () -> Boolean) {
override fun equals(other: Any?): Boolean {
if (this === other) return true
if (other !is CustomAccessibilityAction) return false
if (label != other.label) return false
if (action != other.action) return false
return true
}
override fun hashCode(): Int {
var result = label.hashCode()
result = 31 * result + action.hashCode()
return result
}
override fun toString(): String {
return "CustomAccessibilityAction(label=$label, action=$action)"
}
}
/**
* Accessibility range information, to represent the status of a progress bar or
* seekable progress bar.
*
* @param current current value in the range
* @param range range of this node
* @param steps if greater than `0`, specifies the number of discrete values, evenly distributed
* between across the whole value range. If `0`, any value from the range specified can be chosen.
* Cannot be less than `0`.
*/
class ProgressBarRangeInfo(
val current: Float,
val range: ClosedFloatingPointRange<Float>,
/*@IntRange(from = 0)*/
val steps: Int = 0
) {
companion object {
/**
* Accessibility range information to present indeterminate progress bar
*/
val Indeterminate = ProgressBarRangeInfo(0f, 0f..0f)
}
override fun equals(other: Any?): Boolean {
if (this === other) return true
if (other !is ProgressBarRangeInfo) return false
if (current != other.current) return false
if (range != other.range) return false
if (steps != other.steps) return false
return true
}
override fun hashCode(): Int {
var result = current.hashCode()
result = 31 * result + range.hashCode()
result = 31 * result + steps
return result
}
override fun toString(): String {
return "ProgressBarRangeInfo(current=$current, range=$range, steps=$steps)"
}
}
/**
* Information about the collection.
*
* A collection of items has [rowCount] rows and [columnCount] columns.
* For example, a vertical list is a collection with one column, as many rows as the list items
* that are important for accessibility; A table is a collection with several rows and several
* columns.
*
* @param rowCount the number of rows in the collection, or -1 if unknown
* @param columnCount the number of columns in the collection, or -1 if unknown
*/
class CollectionInfo(val rowCount: Int, val columnCount: Int)
/**
* Information about the item of a collection.
*
* A collection item is contained in a collection, it starts at a given [rowIndex] and
* [columnIndex] in the collection, and spans one or more rows and columns. For example, a header
* of two related table columns starts at the first row and the first column, spans one row and
* two columns.
*
* @param rowIndex the index of the row at which item is located
* @param rowSpan the number of rows the item spans
* @param columnIndex the index of the column at which item is located
* @param columnSpan the number of columns the item spans
*/
class CollectionItemInfo(
val rowIndex: Int,
val rowSpan: Int,
val columnIndex: Int,
val columnSpan: Int
)
/**
* The scroll state of one axis if this node is scrollable.
*
* @param value current 0-based scroll position value (either in pixels, or lazy-item count)
* @param maxValue maximum bound for [value], or [Float.POSITIVE_INFINITY] if still unknown
* @param reverseScrolling for horizontal scroll, when this is `true`, 0 [value] will mean right,
* when`false`, 0 [value] will mean left. For vertical scroll, when this is `true`, 0 [value] will
* mean bottom, when `false`, 0 [value] will mean top
*/
class ScrollAxisRange(
val value: () -> Float,
val maxValue: () -> Float,
val reverseScrolling: Boolean = false
) {
override fun toString(): String =
"ScrollAxisRange(value=${value()}, maxValue=${maxValue()}, " +
"reverseScrolling=$reverseScrolling)"
}
/**
* The type of user interface element. Accessibility services might use this to describe the
* element or do customizations. Most roles can be automatically resolved by the semantics
* properties of this element. But some elements with subtle differences need an exact role. If an
* exact role is not listed, [SemanticsPropertyReceiver.role] should not be set and the framework
* will automatically resolve it.
*/
@Suppress("INLINE_CLASS_DEPRECATED")
@Immutable
inline class Role private constructor(@Suppress("unused") private val value: Int) {
companion object {
/**
* This element is a button control. Associated semantics properties for accessibility:
* [SemanticsProperties.Disabled], [SemanticsActions.OnClick]
*/
val Button = Role(0)
/**
* This element is a Checkbox which is a component that represents two states (checked /
* unchecked). Associated semantics properties for accessibility:
* [SemanticsProperties.Disabled], [SemanticsProperties.StateDescription],
* [SemanticsActions.OnClick]
*/
val Checkbox = Role(1)
/**
* This element is a Switch which is a two state toggleable component that provides on/off
* like options. Associated semantics properties for accessibility:
* [SemanticsProperties.Disabled], [SemanticsProperties.StateDescription],
* [SemanticsActions.OnClick]
*/
val Switch = Role(2)
/**
* This element is a RadioButton which is a component to represent two states, selected and not
* selected. Associated semantics properties for accessibility: [SemanticsProperties.Disabled],
* [SemanticsProperties.StateDescription], [SemanticsActions.OnClick]
*/
val RadioButton = Role(3)
/**
* This element is a Tab which represents a single page of content using a text label and/or
* icon. A Tab also has two states: selected and not selected. Associated semantics properties
* for accessibility: [SemanticsProperties.Disabled], [SemanticsProperties.StateDescription],
* [SemanticsActions.OnClick]
*/
val Tab = Role(4)
/**
* This element is an image. Associated semantics properties for accessibility:
* [SemanticsProperties.ContentDescription]
*/
val Image = Role(5)
}
override fun toString() = when (this) {
Button -> "Button"
Checkbox -> "Checkbox"
Switch -> "Switch"
RadioButton -> "RadioButton"
Tab -> "Tab"
Image -> "Image"
else -> "Unknown"
}
}
/**
* The mode of live region. Live region indicates to accessibility services they should
* automatically notify the user about changes to the node's content description or text, or to
* the content descriptions or text of the node's children (where applicable).
*/
@Suppress("INLINE_CLASS_DEPRECATED")
@Immutable
inline class LiveRegionMode private constructor(@Suppress("unused") private val value: Int) {
companion object {
/**
* Live region mode specifying that accessibility services should announce
* changes to this node.
*/
val Polite = LiveRegionMode(0)
/**
* Live region mode specifying that accessibility services should interrupt
* ongoing speech to immediately announce changes to this node.
*/
val Assertive = LiveRegionMode(1)
}
override fun toString() = when (this) {
Polite -> "Polite"
Assertive -> "Assertive"
else -> "Unknown"
}
}
/**
* SemanticsPropertyReceiver is the scope provided by semantics {} blocks, letting you set
* key/value pairs primarily via extension functions.
*/
interface SemanticsPropertyReceiver {
operator fun <T> set(key: SemanticsPropertyKey<T>, value: T)
}
/**
* Developer-set content description of the semantics node.
*
* If this is not set, accessibility services will present the [text][SemanticsProperties.Text] of
* this node as the content.
*
* This typically should not be set directly by applications, because some screen readers will
* cease presenting other relevant information when this property is present. This is intended
* to be used via Foundation components which are inherently intractable to automatically
* describe, such as Image, Icon, and Canvas.
*/
var SemanticsPropertyReceiver.contentDescription: String
get() = throwSemanticsGetNotSupported()
set(value) { set(SemanticsProperties.ContentDescription, listOf(value)) }
/**
* Developer-set state description of the semantics node.
*
* For example: on/off. If this not set, accessibility services will derive the state from
* other semantics properties, like [ProgressBarRangeInfo], but it is not guaranteed and the format
* will be decided by accessibility services.
*/
var SemanticsPropertyReceiver.stateDescription by SemanticsProperties.StateDescription
/**
* The semantics is represents a range of possible values with a current value.
* For example, when used on a slider control, this will allow screen readers to communicate
* the slider's state.
*/
var SemanticsPropertyReceiver.progressBarRangeInfo by SemanticsProperties.ProgressBarRangeInfo
/**
* The node is marked as heading for accessibility.
*
* @see SemanticsProperties.Heading
*/
fun SemanticsPropertyReceiver.heading() {
this[SemanticsProperties.Heading] = Unit
}
/**
* Accessibility-friendly title for a screen's pane. For accessibility purposes, a pane is a
* visually distinct portion of a window, such as the contents of a open drawer. In order for
* accessibility services to understand a pane's window-like behavior, you should give
* descriptive titles to your app's panes. Accessibility services can then provide more granular
* information to users when a pane's appearance or content changes.
*
* @see SemanticsProperties.PaneTitle
*/
var SemanticsPropertyReceiver.paneTitle by SemanticsProperties.PaneTitle
/**
* Whether this semantics node is disabled. Note that proper [SemanticsActions] should still
* be added when this property is set.
*
* @see SemanticsProperties.Disabled
*/
fun SemanticsPropertyReceiver.disabled() {
this[SemanticsProperties.Disabled] = Unit
}
/**
* This node is marked as live region for accessibility. This indicates to accessibility services
* they should automatically notify the user about changes to the node's content description or
* text, or to the content descriptions or text of the node's children (where applicable). It
* should be used with caution, especially with assertive mode which immediately stops the
* current audio and the user does not hear the rest of the content. An example of proper use is
* a Snackbar which is marked as [LiveRegionMode.Polite].
*
* @see SemanticsProperties.LiveRegion
* @see LiveRegionMode
*/
var SemanticsPropertyReceiver.liveRegion by SemanticsProperties.LiveRegion
/**
* Whether this semantics node is focused. The presence of this property indicates this node is
* focusable
*
* @see SemanticsProperties.Focused
*/
var SemanticsPropertyReceiver.focused by SemanticsProperties.Focused
/**
* Whether this node is specially known to be invisible to the user.
*
* For example, if the node is currently occluded by a dark semitransparent
* pane above it, then for all practical purposes the node is invisible to the user,
* but the system cannot automatically determine that. To make the screen reader linear
* navigation skip over this type of invisible node, this property can be set.
*
* If looking for a way to hide semantics of small items from screen readers because they're
* redundant with semantics of their parent, consider [SemanticsModifier.clearAndSetSemantics]
* instead.
*/
@ExperimentalComposeUiApi
fun SemanticsPropertyReceiver.invisibleToUser() {
this[SemanticsProperties.InvisibleToUser] = Unit
}
/**
* The horizontal scroll state of this node if this node is scrollable.
*/
var SemanticsPropertyReceiver.horizontalScrollAxisRange
by SemanticsProperties.HorizontalScrollAxisRange
/**
* The vertical scroll state of this node if this node is scrollable.
*/
var SemanticsPropertyReceiver.verticalScrollAxisRange
by SemanticsProperties.VerticalScrollAxisRange
/**
* Whether this semantics node represents a Popup. Not to be confused with if this node is
* _part of_ a Popup.
*/
fun SemanticsPropertyReceiver.popup() {
this[SemanticsProperties.IsPopup] = Unit
}
/**
* Whether this element is a Dialog. Not to be confused with if this element is _part of_ a Dialog.
*/
fun SemanticsPropertyReceiver.dialog() {
this[SemanticsProperties.IsDialog] = Unit
}
/**
* The type of user interface element. Accessibility services might use this to describe the
* element or do customizations. Most roles can be automatically resolved by the semantics
* properties of this element. But some elements with subtle differences need an exact role. If
* an exact role is not listed in [Role], this property should not be set and the framework will
* automatically resolve it.
*/
var SemanticsPropertyReceiver.role by SemanticsProperties.Role
// TODO(b/138172781): Move to FoundationSemanticsProperties.kt
/**
* Test tag attached to this semantics node.
*/
var SemanticsPropertyReceiver.testTag by SemanticsProperties.TestTag
/**
* Text of the semantics node. It must be real text instead of developer-set content description.
*
* @see SemanticsPropertyReceiver.editableText
*/
var SemanticsPropertyReceiver.text: AnnotatedString
get() = throwSemanticsGetNotSupported()
set(value) { set(SemanticsProperties.Text, listOf(value)) }
/**
* Input text of the text field with visual transformation applied to it. It must be a real text
* entered by the user with visual transformation applied on top of the input text instead of a
* developer-set content description.
*/
var SemanticsPropertyReceiver.editableText by SemanticsProperties.EditableText
/**
* Text selection range for the text field.
*/
var SemanticsPropertyReceiver.textSelectionRange by SemanticsProperties.TextSelectionRange
/**
* Contains the IME action provided by the node.
*
* For example, "go to next form field" or "submit".
*/
var SemanticsPropertyReceiver.imeAction by SemanticsProperties.ImeAction
/**
* Whether this element is selected (out of a list of possible selections).
*
* The presence of this property indicates that the element is selectable.
*/
var SemanticsPropertyReceiver.selected by SemanticsProperties.Selected
/**
* This semantics marks node as a collection and provides the required information.
*
* @see collectionItemInfo
*/
var SemanticsPropertyReceiver.collectionInfo by SemanticsProperties.CollectionInfo
/**
* This semantics marks node as an items of a collection and provides the required information.
*
* If you mark items of a collection, you should also be marking the collection with
* [collectionInfo].
*/
var SemanticsPropertyReceiver.collectionItemInfo by SemanticsProperties.CollectionItemInfo
/**
* The state of a toggleable component.
*
* The presence of this property indicates that the element is toggleable.
*/
var SemanticsPropertyReceiver.toggleableState by SemanticsProperties.ToggleableState
/**
* The node is marked as a password.
*/
fun SemanticsPropertyReceiver.password() {
this[SemanticsProperties.Password] = Unit
}
/**
* Mark semantics node that contains invalid input or error.
*
* @param [description] a localized description explaining an error to the accessibility user
*/
fun SemanticsPropertyReceiver.error(description: String) {
this[SemanticsProperties.Error] = description
}
/**
* The index of an item identified by a given key. The key is usually defined during the creation
* of the container. If the key did not match any of the items' keys, the [mapping] must return -1.
*/
fun SemanticsPropertyReceiver.indexForKey(mapping: (Any) -> Int) {
this[SemanticsProperties.IndexForKey] = mapping
}
/**
* The node is marked as a collection of horizontally or vertically stacked selectable elements.
*
* Unlike [collectionInfo] which marks a collection of any elements and asks developer to
* provide all the required information like number of elements etc., this semantics will
* populate the number of selectable elements automatically. Note that if you use this semantics
* with lazy collections, it won't get the number of elements in the collection.
*
* @see SemanticsPropertyReceiver.selected
*/
fun SemanticsPropertyReceiver.selectableGroup() {
this[SemanticsProperties.SelectableGroup] = Unit
}
/**
* Custom actions which are defined by app developers.
*/
var SemanticsPropertyReceiver.customActions by SemanticsActions.CustomActions
/**
* Action to get a Text/TextField node's [TextLayoutResult]. The result is the first element
* of layout (the argument of the AccessibilityAction).
*
* @param label Optional label for this action.
* @param action Action to be performed when the [SemanticsActions.GetTextLayoutResult] is called.
*/
fun SemanticsPropertyReceiver.getTextLayoutResult(
label: String? = null,
action: ((MutableList<TextLayoutResult>) -> Boolean)?
) {
this[SemanticsActions.GetTextLayoutResult] = AccessibilityAction(label, action)
}
/**
* Action to be performed when the node is clicked (single-tapped).
*
* @param label Optional label for this action.
* @param action Action to be performed when the [SemanticsActions.OnClick] is called.
*/
fun SemanticsPropertyReceiver.onClick(label: String? = null, action: (() -> Boolean)?) {
this[SemanticsActions.OnClick] = AccessibilityAction(label, action)
}
/**
* Action to be performed when the node is long clicked (long-pressed).
*
* @param label Optional label for this action.
* @param action Action to be performed when the [SemanticsActions.OnLongClick] is called.
*/
fun SemanticsPropertyReceiver.onLongClick(label: String? = null, action: (() -> Boolean)?) {
this[SemanticsActions.OnLongClick] = AccessibilityAction(label, action)
}
/**
* Action to scroll by a specified amount.
*
* Expected to be used in conjunction with verticalScrollAxisRange/horizontalScrollAxisRange.
*
* @param label Optional label for this action.
* @param action Action to be performed when the [SemanticsActions.ScrollBy] is called.
*/
fun SemanticsPropertyReceiver.scrollBy(
label: String? = null,
action: ((x: Float, y: Float) -> Boolean)?
) {
this[SemanticsActions.ScrollBy] = AccessibilityAction(label, action)
}
/**
* Action to scroll a container to the index of one of its items.
*
* The [action] should throw an [IllegalArgumentException] if the index is out of bounds.
*/
fun SemanticsPropertyReceiver.scrollToIndex(
label: String? = null,
action: (Int) -> Boolean
) {
this[SemanticsActions.ScrollToIndex] = AccessibilityAction(label, action)
}
/**
* Action to set the current value of the progress bar.
*
* Expected to be used in conjunction with progressBarRangeInfo.
*
* @param label Optional label for this action.
* @param action Action to be performed when the [SemanticsActions.SetProgress] is called.
*/
fun SemanticsPropertyReceiver.setProgress(label: String? = null, action: ((Float) -> Boolean)?) {
this[SemanticsActions.SetProgress] = AccessibilityAction(label, action)
}
/**
* Action to set the text contents of this node.
*
* Expected to be used on editable text fields.
*
* @param label Optional label for this action.
* @param action Action to be performed when the [SemanticsActions.SetText] is called.
*/
fun SemanticsPropertyReceiver.setText(
label: String? = null,
action: ((AnnotatedString) -> Boolean)?
) {
this[SemanticsActions.SetText] = AccessibilityAction(label, action)
}
/**
* Action to set text selection by character index range.
*
* If this action is provided, the selection data must be provided
* using [textSelectionRange].
*
* @param label Optional label for this action.
* @param action Action to be performed when the [SemanticsActions.SetSelection] is called.
*/
fun SemanticsPropertyReceiver.setSelection(
label: String? = null,
action: ((startIndex: Int, endIndex: Int, traversalMode: Boolean) -> Boolean)?
) {
this[SemanticsActions.SetSelection] = AccessibilityAction(label, action)
}
/**
* Action to copy the text to the clipboard.
*
* @param label Optional label for this action.
* @param action Action to be performed when the [SemanticsActions.CopyText] is called.
*/
fun SemanticsPropertyReceiver.copyText(
label: String? = null,
action: (() -> Boolean)?
) {
this[SemanticsActions.CopyText] = AccessibilityAction(label, action)
}
/**
* Action to cut the text and copy it to the clipboard.
*
* @param label Optional label for this action.
* @param action Action to be performed when the [SemanticsActions.CutText] is called.
*/
fun SemanticsPropertyReceiver.cutText(
label: String? = null,
action: (() -> Boolean)?
) {
this[SemanticsActions.CutText] = AccessibilityAction(label, action)
}
/**
* This function adds the [SemanticsActions.PasteText] to the [SemanticsPropertyReceiver].
* Use it to indicate that element is open for accepting paste data from the clipboard. There is
* no need to check if the clipboard data available as this is done by the framework.
* For this action to be triggered, the element must also have the [SemanticsProperties.Focused]
* property set.
*
* @param label Optional label for this action.
* @param action Action to be performed when the [SemanticsActions.PasteText] is called.
*
* @see focused
*/
fun SemanticsPropertyReceiver.pasteText(
label: String? = null,
action: (() -> Boolean)?
) {
this[SemanticsActions.PasteText] = AccessibilityAction(label, action)
}
/**
* Action to expand an expandable node.
*
* @param label Optional label for this action.
* @param action Action to be performed when the [SemanticsActions.Expand] is called.
*/
fun SemanticsPropertyReceiver.expand(
label: String? = null,
action: (() -> Boolean)?
) {
this[SemanticsActions.Expand] = AccessibilityAction(label, action)
}
/**
* Action to collapse an expandable node.
*
* @param label Optional label for this action.
* @param action Action to be performed when the [SemanticsActions.Collapse] is called.
*/
fun SemanticsPropertyReceiver.collapse(
label: String? = null,
action: (() -> Boolean)?
) {
this[SemanticsActions.Collapse] = AccessibilityAction(label, action)
}
/**
* Action to dismiss a dismissible node.
*
* @param label Optional label for this action.
* @param action Action to be performed when the [SemanticsActions.Dismiss] is called.
*/
fun SemanticsPropertyReceiver.dismiss(
label: String? = null,
action: (() -> Boolean)?
) {
this[SemanticsActions.Dismiss] = AccessibilityAction(label, action)
}