androidx.core.view

Kotlin |Java

Interfaces

VisibilityListener	Listens to changes in visibility as reported by `ActionProvider#refreshVisibility()`.
OnDragStartListener	Interface definition for a callback to be invoked when a drag start gesture is detected.
LayoutInflaterFactory	Used with `LayoutInflaterCompat.setFactory()`.
OnActionExpandListener	Interface definition for a callback to be invoked when a menu item marked with is expanded or collapsed.
NestedScrollingChild	This interface should be implemented by `View` subclasses that wish to support dispatching nested scrolling operations to a cooperating parent `ViewGroup`.
NestedScrollingChild2	This interface should be implemented by `View` subclasses that wish to support dispatching nested scrolling operations to a cooperating parent `ViewGroup`.
NestedScrollingChild3	This interface should be implemented by `View` subclasses that wish to support dispatching nested scrolling operations to a cooperating parent `ViewGroup`.
NestedScrollingParent	This interface should be implemented by `ViewGroup` subclasses that wish to support scrolling operations delegated by a nested child view.
NestedScrollingParent2	This interface should be implemented by `ViewGroup` subclasses that wish to support scrolling operations delegated by a nested child view.
NestedScrollingParent3	This interface should be implemented by `ViewGroup` subclasses that wish to support scrolling operations delegated by a nested child view.
OnApplyWindowInsetsListener	Listener for applying window insets on a view in a custom way.
ScrollingView	An interface that can be implemented by Views to provide scroll related APIs.
TintableBackgroundView	Interface which allows a `android.view.View` to receive background tinting calls from `ViewCompat` when running on API v20 devices or lower.
OnUnhandledKeyEventListenerCompat	Interface definition for a callback to be invoked when a hardware key event hasn't been handled by the view hierarchy.
ViewPropertyAnimatorListener	An animation listener receives notifications from an animation.
ViewPropertyAnimatorUpdateListener	Implementors of this interface can add themselves as update listeners to an `ViewPropertyAnimatorCompat` instance to receive callbacks on every animation frame, after the current frame's values have been calculated for that `ViewPropertyAnimatorCompat`.

Classes

AccessibilityDelegateCompat	Helper for accessing `AccessibilityDelegate`.
ActionProvider	This class is a mediator for accomplishing a given task, for example sharing a file.
DisplayCompat	A class for retrieving the physical display size from a device.
DisplayCutoutCompat	Represents the area of the display that is not functional for displaying content.
DragAndDropPermissionsCompat	Helper for accessing features in `android.view.DragAndDropPermissions` a backwards compatible fashion.
DragStartHelper	DragStartHelper is a utility class for implementing drag and drop support.
GestureDetectorCompat	Detects various gestures and events using the supplied `MotionEvent`s.
GravityCompat	Compatibility shim for accessing newer functionality from `android.view.Gravity`.
InputDeviceCompat	Helper class for accessing values in `android.view.InputDevice`.
LayoutInflaterCompat	Helper for accessing features in `LayoutInflater`.
MarginLayoutParamsCompat	Helper for accessing API features in `MarginLayoutParams` in a backwards compatible way.
MenuCompat	Helper for accessing features in `android.view.Menu`.
MenuItemCompat	Helper for accessing features in `android.view.MenuItem`.
MotionEventCompat	Helper for accessing features in `MotionEvent`.
NestedScrollingChildHelper	Helper class for implementing nested scrolling child views compatible with Android platform versions earlier than Android 5.
NestedScrollingParentHelper	Helper class for implementing nested scrolling parent views compatible with Android platform versions earlier than Android 5.
OneShotPreDrawListener	An OnPreDrawListener that will remove itself after one OnPreDraw call.
PointerIconCompat	Helper for accessing features in `android.view.PointerIcon` in a backwards compatible fashion.
ScaleGestureDetectorCompat	Helper for accessing features in `ScaleGestureDetector`.
VelocityTrackerCompat	Helper for accessing features in `VelocityTracker`.
ViewCompat	Helper for accessing features in `View`.
ViewConfigurationCompat	Helper for accessing features in `ViewConfiguration`.
ViewGroupCompat	Helper for accessing features in `ViewGroup`.
ViewParentCompat	Helper for accessing features in `ViewParent`.
ViewPropertyAnimatorCompat
ViewPropertyAnimatorListenerAdapter	This adapter class provides empty implementations of the methods from `ViewPropertyAnimatorListener`.
WindowCompat	Helper for accessing features in `Window`.
WindowInsetsCompat	Describes a set of insets for window content.

Extension functions summary

For android.view.Menu
operator Boolean	`Menu.contains(item: MenuItem)` Returns `true` if item is found in this menu.
Unit	`Menu.forEach(action: (item: MenuItem) -> Unit)` Performs the given action on each item in this menu.
Unit	`Menu.forEachIndexed(action: (index: Int, item: MenuItem) -> Unit)` Performs the given action on each item in this menu, providing its sequential index.
operator MenuItem	`Menu.get(index: Int)` Returns the menu at index.
Boolean	`Menu.isEmpty()` Returns true if this menu contains no items.
Boolean	`Menu.isNotEmpty()` Returns true if this menu contains one or more items.
operator MutableIterator<MenuItem>	`Menu.iterator()` Returns a MutableIterator over the items in this menu.
operator Unit	`Menu.minusAssign(item: MenuItem)` Removes item from this menu.

For android.view.View
Unit	`View.doOnAttach(crossinline action: (view: View) -> Unit)` Performs the given action when this view is attached to a window.
Unit	`View.doOnDetach(crossinline action: (view: View) -> Unit)` Performs the given action when this view is detached from a window.
Unit	`View.doOnLayout(crossinline action: (view: View) -> Unit)` Performs the given action when this view is laid out.
Unit	`View.doOnNextLayout(crossinline action: (view: View) -> Unit)` Performs the given action when this view is next laid out.
OneShotPreDrawListener	`View.doOnPreDraw(crossinline action: (view: View) -> Unit)` Performs the given action when the view tree is about to be drawn.
Bitmap	`View.drawToBitmap(config: Config = Bitmap.Config.ARGB_8888)` Return a Bitmap representation of this View.
Runnable	`View.postDelayed(delayInMillis: Long, crossinline action: () -> Unit)` Version of View.postDelayed which re-orders the parameters, allowing the action to be placed outside of parentheses.
Runnable	`View.postOnAnimationDelayed(delayInMillis: Long, crossinline action: () -> Unit)` Version of View.postOnAnimationDelayed which re-orders the parameters, allowing the action to be placed outside of parentheses.
Unit	`View.setPadding(@Px size: Int)` Sets the view's padding.
Unit	`View.updateLayoutParams(block: LayoutParams.() -> Unit)` Executes block with the View's layoutParams and reassigns the layoutParams with the updated version.
Unit	`View.updateLayoutParams(block: T.() -> Unit)` Executes block with a typed version of the View's layoutParams and reassigns the layoutParams with the updated version.
Unit	`View.updatePadding(@Px left: Int = paddingLeft, @Px top: Int = paddingTop, @Px right: Int = paddingRight, @Px bottom: Int = paddingBottom)` Updates this view's padding.
Unit	`View.updatePaddingRelative(@Px start: Int = paddingStart, @Px top: Int = paddingTop, @Px end: Int = paddingEnd, @Px bottom: Int = paddingBottom)` Updates this view's relative padding.

For android.view.ViewGroup
operator Boolean	`ViewGroup.contains(view: View)` Returns `true` if view is found in this view group.
Unit	`ViewGroup.forEach(action: (view: View) -> Unit)` Performs the given action on each view in this view group.
Unit	`ViewGroup.forEachIndexed(action: (index: Int, view: View) -> Unit)` Performs the given action on each view in this view group, providing its sequential index.
operator View	`ViewGroup.get(index: Int)` Returns the view at index.
Boolean	`ViewGroup.isEmpty()` Returns true if this view group contains no views.
Boolean	`ViewGroup.isNotEmpty()` Returns true if this view group contains one or more views.
operator MutableIterator<View>	`ViewGroup.iterator()` Returns a MutableIterator over the views in this view group.
operator Unit	`ViewGroup.minusAssign(view: View)` Removes view from this view group.
operator Unit	`ViewGroup.plusAssign(view: View)` Adds view to this view group.

For android.view.ViewGroup.MarginLayoutParams
Unit	`MarginLayoutParams.setMargins(@Px size: Int)` Sets the margins in the ViewGroup's MarginLayoutParams.
Unit	`MarginLayoutParams.updateMargins(@Px left: Int = leftMargin, @Px top: Int = topMargin, @Px right: Int = rightMargin, @Px bottom: Int = bottomMargin)` Updates the margins in the ViewGroup's ViewGroup.MarginLayoutParams.
Unit	`MarginLayoutParams.updateMarginsRelative(@Px start: Int = marginStart, @Px top: Int = topMargin, @Px end: Int = marginEnd, @Px bottom: Int = bottomMargin)` Updates the relative margins in the ViewGroup's MarginLayoutParams.

Extension properties summary

For android.view.Menu
Sequence<MenuItem>	`Menu.children()` Returns a Sequence over the items in this menu.
Int	`Menu.size()` Returns the number of items in this menu.

For android.view.View
Sequence<View>	`View.allViews()` Returns a Sequence over this view and its descendants recursively.
Sequence<ViewParent>	`View.ancestors()` Returns a Sequence of the parent chain of this view by repeatedly calling View.getParent.
Boolean	`View.isGone()` Returns true when this view's visibility is View.GONE, false otherwise.
Boolean	`View.isInvisible()` Returns true when this view's visibility is View.INVISIBLE, false otherwise.
Boolean	`View.isVisible()` Returns true when this view's visibility is View.VISIBLE, false otherwise.
Int	`View.marginBottom()` Returns the bottom margin if this view's LayoutParams is a ViewGroup.MarginLayoutParams, otherwise 0.
Int	`View.marginEnd()` Returns the end margin if this view's LayoutParams is a ViewGroup.MarginLayoutParams, otherwise 0.
Int	`View.marginLeft()` Returns the left margin if this view's LayoutParams is a ViewGroup.MarginLayoutParams, otherwise 0.
Int	`View.marginRight()` Returns the right margin if this view's LayoutParams is a ViewGroup.MarginLayoutParams, otherwise 0.
Int	`View.marginStart()` Returns the start margin if this view's LayoutParams is a ViewGroup.MarginLayoutParams, otherwise 0.
Int	`View.marginTop()` Returns the top margin if this view's LayoutParams is a ViewGroup.MarginLayoutParams, otherwise 0.

For android.view.ViewGroup
Sequence<View>	`ViewGroup.children()` Returns a Sequence over the immediate child views in this view group.
Sequence<View>	`ViewGroup.descendants()` Returns a Sequence over the child views in this view group recursively.
Int	`ViewGroup.size()` Returns the number of views in this view group.

Extension functions

contains

operator fun Menu.contains(item: MenuItem): Boolean

Returns true if item is found in this menu.

contains

inline operator fun ViewGroup.contains(view: View): Boolean

Returns true if view is found in this view group.

doOnAttach

inline fun View.doOnAttach(crossinline action: (view: View) -> Unit): Unit

Performs the given action when this view is attached to a window. If the view is already attached to a window the action will be performed immediately, otherwise the action will be performed after the view is next attached.

The action will only be invoked once, and any listeners will then be removed.

See Also

doOnDetach

doOnDetach

inline fun View.doOnDetach(crossinline action: (view: View) -> Unit): Unit

Performs the given action when this view is detached from a window. If the view is not attached to a window the action will be performed immediately, otherwise the action will be performed after the view is detached from its current window.

The action will only be invoked once, and any listeners will then be removed.

See Also

doOnAttach

doOnLayout

inline fun View.doOnLayout(crossinline action: (view: View) -> Unit): Unit

Performs the given action when this view is laid out. If the view has been laid out and it has not requested a layout, the action will be performed straight away, otherwise the action will be performed after the view is next laid out.

The action will only be invoked once on the next layout and then removed.

See Also

doOnNextLayout

doOnNextLayout

inline fun View.doOnNextLayout(crossinline action: (view: View) -> Unit): Unit

Performs the given action when this view is next laid out.

The action will only be invoked once on the next layout and then removed.

See Also

doOnLayout

doOnPreDraw

inline fun View.doOnPreDraw(crossinline action: (view: View) -> Unit): OneShotPreDrawListener

Performs the given action when the view tree is about to be drawn.

The action will only be invoked once prior to the next draw and then removed.

drawToBitmap

fun View.drawToBitmap(config: Config = Bitmap.Config.ARGB_8888): Bitmap

Return a Bitmap representation of this View.

The resulting bitmap will be the same width and height as this view's current layout dimensions. This does not take into account any transformations such as scale or translation.

Note, this will use the software rendering pipeline to draw the view to the bitmap. This may result with different drawing to what is rendered on a hardware accelerated canvas (such as the device screen).

If this view has not been laid out this method will throw a IllegalStateException.

Parameters
config: Config = Bitmap.Config.ARGB_8888	Bitmap config of the desired bitmap. Defaults to Bitmap.Config.ARGB_8888.

forEach

inline fun Menu.forEach(action: (item: MenuItem) -> Unit): Unit

Performs the given action on each item in this menu.

forEach

inline fun ViewGroup.forEach(action: (view: View) -> Unit): Unit

Performs the given action on each view in this view group.

forEachIndexed

inline fun Menu.forEachIndexed(action: (index: Int, item: MenuItem) -> Unit): Unit

Performs the given action on each item in this menu, providing its sequential index.

forEachIndexed

inline fun ViewGroup.forEachIndexed(action: (index: Int, view: View) -> Unit): Unit

Performs the given action on each view in this view group, providing its sequential index.

get

inline operator fun Menu.get(index: Int): MenuItem

Returns the menu at index.

Exceptions
`IndexOutOfBoundsException`	if index is less than 0 or greater than or equal to the count.

get

operator fun ViewGroup.get(index: Int): View

Returns the view at index.

Exceptions
`IndexOutOfBoundsException`	if index is less than 0 or greater than or equal to the count.

isEmpty

inline fun Menu.isEmpty(): Boolean

Returns true if this menu contains no items.

isEmpty

inline fun ViewGroup.isEmpty(): Boolean

Returns true if this view group contains no views.

isNotEmpty

inline fun Menu.isNotEmpty(): Boolean

Returns true if this menu contains one or more items.

isNotEmpty

inline fun ViewGroup.isNotEmpty(): Boolean

Returns true if this view group contains one or more views.

iterator

operator fun Menu.iterator(): MutableIterator<MenuItem>

Returns a MutableIterator over the items in this menu.

iterator

operator fun ViewGroup.iterator(): MutableIterator<View>

Returns a MutableIterator over the views in this view group.

minusAssign

inline operator fun Menu.minusAssign(item: MenuItem): Unit

Removes item from this menu.

minusAssign

inline operator fun ViewGroup.minusAssign(view: View): Unit

Removes view from this view group.

plusAssign

inline operator fun ViewGroup.plusAssign(view: View): Unit

Adds view to this view group.

postDelayed

inline fun View.postDelayed(
    delayInMillis: Long, 
    crossinline action: () -> Unit
): Runnable

Version of View.postDelayed which re-orders the parameters, allowing the action to be placed outside of parentheses.

view.postDelayed(200) {
    doSomething()
}

Return
the created Runnable

postOnAnimationDelayed

@RequiresApi(16) inline fun View.postOnAnimationDelayed(
    delayInMillis: Long, 
    crossinline action: () -> Unit
): Runnable

Version of View.postOnAnimationDelayed which re-orders the parameters, allowing the action to be placed outside of parentheses.

view.postOnAnimationDelayed(16) {
    doSomething()
}

Return
the created Runnable

setMargins

inline fun MarginLayoutParams.setMargins(@Px size: Int): Unit

Sets the margins in the ViewGroup's MarginLayoutParams. This version of the method sets all axes to the provided size.

See Also

ViewGroup.MarginLayoutParams.setMargins

setPadding

inline fun View.setPadding(@Px size: Int): Unit

Sets the view's padding. This version of the method sets all axes to the provided size.

See Also

View.setPadding

updateLayoutParams

inline fun View.updateLayoutParams(block: LayoutParams.() -> Unit): Unit

Executes block with the View's layoutParams and reassigns the layoutParams with the updated version.

See Also

updateLayoutParams

@JvmName("updateLayoutParamsTyped") inline fun <reified T : LayoutParams> View.updateLayoutParams(block: T.() -> Unit): Unit

Executes block with a typed version of the View's layoutParams and reassigns the layoutParams with the updated version.

See Also

updateMargins

inline fun MarginLayoutParams.updateMargins(
    @Px left: Int = leftMargin, 
    @Px top: Int = topMargin, 
    @Px right: Int = rightMargin, 
    @Px bottom: Int = bottomMargin
): Unit

Updates the margins in the ViewGroup's ViewGroup.MarginLayoutParams. This version of the method allows using named parameters to just set one or more axes.

See Also

ViewGroup.MarginLayoutParams.setMargins

updateMarginsRelative

@RequiresApi(17) inline fun MarginLayoutParams.updateMarginsRelative(
    @Px start: Int = marginStart, 
    @Px top: Int = topMargin, 
    @Px end: Int = marginEnd, 
    @Px bottom: Int = bottomMargin
): Unit

Updates the relative margins in the ViewGroup's MarginLayoutParams. This version of the method allows using named parameters to just set one or more axes.

See Also

ViewGroup.MarginLayoutParams.setMargins

updatePadding

inline fun View.updatePadding(
    @Px left: Int = paddingLeft, 
    @Px top: Int = paddingTop, 
    @Px right: Int = paddingRight, 
    @Px bottom: Int = paddingBottom
): Unit

Updates this view's padding. This version of the method allows using named parameters to just set one or more axes.

See Also

View.setPadding

updatePaddingRelative

@RequiresApi(17) inline fun View.updatePaddingRelative(
    @Px start: Int = paddingStart, 
    @Px top: Int = paddingTop, 
    @Px end: Int = paddingEnd, 
    @Px bottom: Int = paddingBottom
): Unit

Updates this view's relative padding. This version of the method allows using named parameters to just set one or more axes.

See Also

View.setPaddingRelative

Extension properties

allViews

val View.allViews: Sequence<View>

Returns a Sequence over this view and its descendants recursively. This is a depth-first traversal similar to View.findViewById. A view with no children will return a single-element sequence of itself.

See Also

ViewGroup.descendants

ancestors

val View.ancestors: Sequence<ViewParent>

Returns a Sequence of the parent chain of this view by repeatedly calling View.getParent. An unattached view will return a zero-element sequence.

See Also

ViewGroup.descendants

children

val Menu.children: Sequence<MenuItem>

Returns a Sequence over the items in this menu.

children

val ViewGroup.children: Sequence<View>

Returns a Sequence over the immediate child views in this view group.

See Also

View.allViews
ViewGroup.descendants

descendants

val ViewGroup.descendants: Sequence<View>

Returns a Sequence over the child views in this view group recursively. This performs a depth-first traversal. A view with no children will return a zero-element sequence.

See Also

View.allViews
ViewGroup.children
View.ancestors

isGone

inline var View.isGone: Boolean

Returns true when this view's visibility is View.GONE, false otherwise.

if (view.isGone) {
    // Behavior...
}

Setting this property to true sets the visibility to View.GONE, false to View.VISIBLE.

view.isGone = true

isInvisible

inline var View.isInvisible: Boolean

Returns true when this view's visibility is View.INVISIBLE, false otherwise.

if (view.isInvisible) {
    // Behavior...
}

Setting this property to true sets the visibility to View.INVISIBLE, false to View.VISIBLE.

view.isInvisible = true

isVisible

inline var View.isVisible: Boolean

Returns true when this view's visibility is View.VISIBLE, false otherwise.

if (view.isVisible) {
    // Behavior...
}

Setting this property to true sets the visibility to View.VISIBLE, false to View.GONE.

view.isVisible = true

marginBottom

inline val View.marginBottom: Int

Returns the bottom margin if this view's LayoutParams is a ViewGroup.MarginLayoutParams, otherwise 0.

See Also

ViewGroup.MarginLayoutParams

marginEnd

inline val View.marginEnd: Int

Returns the end margin if this view's LayoutParams is a ViewGroup.MarginLayoutParams, otherwise 0.

See Also

marginLeft

inline val View.marginLeft: Int

Returns the left margin if this view's LayoutParams is a ViewGroup.MarginLayoutParams, otherwise 0.

See Also

ViewGroup.MarginLayoutParams

marginRight

inline val View.marginRight: Int

Returns the right margin if this view's LayoutParams is a ViewGroup.MarginLayoutParams, otherwise 0.

See Also

ViewGroup.MarginLayoutParams

marginStart

inline val View.marginStart: Int

Returns the start margin if this view's LayoutParams is a ViewGroup.MarginLayoutParams, otherwise 0.

See Also

marginTop

inline val View.marginTop: Int

Returns the top margin if this view's LayoutParams is a ViewGroup.MarginLayoutParams, otherwise 0.

See Also

ViewGroup.MarginLayoutParams

size

inline val Menu.size: Int

Returns the number of items in this menu.

size

inline val ViewGroup.size: Int

Returns the number of views in this view group.