PreviewView


class PreviewView : FrameLayout


Custom View that displays the camera feed for CameraX's Preview use case.

This class manages the preview Surface's lifecycle. It internally uses either a TextureView or SurfaceView to display the camera feed, and applies required transformations on them to correctly display the preview, this involves correcting their aspect ratio, scale and rotation.

If PreviewView uses a SurfaceView to display the preview stream, be careful when overlapping a View that's initially not visible (either INVISIBLE or GONE) on top of it. When the SurfaceView is attached to the display window, it calls requestTransparentRegion which requests a computation of the transparent regions on the display. At this point, the View isn't visible, causing the overlapped region between the SurfaceView and the View to be considered transparent. Later if the View becomes visible, it will not be displayed on top of SurfaceView. A way around this is to call requestTransparentRegion right after making the View visible, or initially hiding the View by setting its opacity to 0, then setting it to 1.0F to show it.

There are some limitations of transition animations to SurfaceView and TextureView, which applies to PreviewView as well.

See also

Summary

Nested types

The implementation mode of a PreviewView.

Options for scaling the preview vis-à-vis its container PreviewView.

Definitions for the preview stream state.

Public constructors

@UiThread
PreviewView(context: Context, attrs: AttributeSet?, defStyleAttr: Int)
@UiThread
PreviewView(
    context: Context,
    attrs: AttributeSet?,
    defStyleAttr: Int,
    defStyleRes: Int
)

Public functions

Bitmap?

Returns a Bitmap representation of the content displayed on the PreviewView, or null if the camera preview hasn't started yet.

CameraController?

Get the CameraController.

PreviewView.ImplementationMode

Returns the ImplementationMode.

MeteringPointFactory

Gets the MeteringPointFactory for the camera currently connected to the PreviewView, if any.

OutputTransform?

Gets the OutputTransform associated with the PreviewView.

LiveData<PreviewView.StreamState!>

Gets a LiveData for the preview StreamState.

PreviewView.ScaleType

Returns the ScaleType currently applied to the preview.

ImageCapture.ScreenFlash?

Returns an ImageCapture.ScreenFlash implementation based on the Window instance set via setScreenFlashWindow.

Matrix?

Gets the transformation matrix from camera sensor to PreviewView.

Preview.SurfaceProvider

Gets a Preview.SurfaceProvider to be used with setSurfaceProvider.

ViewPort?

Gets a ViewPort based on the current status of PreviewView.

ViewPort?
@UiThread
getViewPort(targetRotation: Int)

Gets a ViewPort with custom target rotation.

Boolean
Boolean
Unit

Sets the CameraController.

Unit

Sets the ImplementationMode for the PreviewView.

Unit

Applies a ScaleType to the preview.

Unit

Sets the color of the top overlay view during screen flash.

Unit
@UiThread
setScreenFlashWindow(screenFlashWindow: Window?)

Sets a Window instance for subsequent photo capture requests with FLASH_MODE_SCREEN set.

Inherited Constants

From android.view.View
const Int
const Int
const Int
const Int
const Int
const Int
const Property<View!, Float!>!
const Int
const String!
AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_DATE = "creditCardExpirationDate"
const String!
AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_DAY = "creditCardExpirationDay"
const String!
AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_MONTH = "creditCardExpirationMonth"
const String!
AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_YEAR = "creditCardExpirationYear"
const String!
const String!
AUTOFILL_HINT_CREDIT_CARD_SECURITY_CODE = "creditCardSecurityCode"
const String!
const String!
const String!
const String!
const String!
const String!
const String!
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int

This property is deprecated.

const Int

This property is deprecated.

const Int

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const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const Int
const Int
const Int
const Int
const Int
const Int
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const Int
const Int
const Int
const Int
const Int
const Int
const Int
GONE = 8
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
KEEP_SCREEN_ON = 67108864
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
NO_ID = -1
const Int
const Int
const Int
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const IntArray<Int>!
const Property<View!, Float!>!
const Property<View!, Float!>!
const Property<View!, Float!>!
const Property<View!, Float!>!
const Property<View!, Float!>!
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const IntArray<Int>!
const IntArray<Int>!
const Int
const Int

This property is deprecated.

const Int

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const Int

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const Int

This property is deprecated.

const Int

This property is deprecated.

const Int

This property is deprecated.

const Int

This property is deprecated.

const Int

This property is deprecated.

const Int

This property is deprecated.

const Int

This property is deprecated.

const Int

This property is deprecated.

const Int

This property is deprecated.

const Int

This property is deprecated.

const Int

This property is deprecated.

const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Int
const Property<View!, Float!>!
const Property<View!, Float!>!
const Property<View!, Float!>!
const String!
VIEW_LOG_TAG = "View"
const Int
const IntArray<Int>!
const Property<View!, Float!>!
const Property<View!, Float!>!
const Property<View!, Float!>!
From android.view.ViewGroup
const Int
const Int
const Int
const Int
const Int
const Int
const Int

This property is deprecated.

const Int

This property is deprecated.

const Int

This property is deprecated.

const Int

This property is deprecated.

Inherited functions

From android.widget.FrameLayout
From android.view.View
Unit
Unit
Unit
ViewPropertyAnimator!
Unit
Unit
Boolean
Unit
Unit

This function is deprecated.

Unit
Boolean
Boolean
Boolean
Boolean
Boolean
Boolean
Unit
Unit
Unit
Boolean
Unit
Unit
java-static Int
combineMeasuredStates(curState: Int, newState: Int)
Int
Int
Int
Unit
WindowInsets!
computeSystemWindowInsets(in: WindowInsets!, outLocalInsets: Rect!)
Int
Int
Int
AccessibilityNodeInfo!
Unit
Unit

This function is deprecated.

Boolean
Boolean
dispatchNestedFling(velocityX: Float, velocityY: Float, consumed: Boolean)
Boolean
dispatchNestedPreFling(velocityX: Float, velocityY: Float)
Boolean
dispatchNestedPrePerformAccessibilityAction(
    action: Int,
    arguments: Bundle!
)
Boolean
dispatchNestedPreScroll(
    dx: Int,
    dy: Int,
    consumed: IntArray!,
    offsetInWindow: IntArray!
)
Boolean
dispatchNestedScroll(
    dxConsumed: Int,
    dyConsumed: Int,
    dxUnconsumed: Int,
    dyUnconsumed: Int,
    offsetInWindow: IntArray!
)
Boolean
Unit
draw(canvas: Canvas!)
Unit
OnBackInvokedDispatcher!
T!
<T : View?> findViewById(id: Int)
T!
<T : View?> findViewWithTag(tag: Any!)
Boolean

This function is deprecated.

Unit
forceHasOverlappingRendering(hasOverlappingRendering: Boolean)
Unit
Unit
generateDisplayHash(
    hashAlgorithm: String!,
    bounds: Rect!,
    executor: Executor!,
    callback: DisplayHashResultCallback!
)
java-static Int
View.AccessibilityDelegate!
Int
AccessibilityNodeProvider!
CharSequence!
Int
Int
String!
String!
Float
Animation!
Matrix!
IBinder!
IntArray<Int>!
(Mutable)Map<Int!, Int!>!
Array<String!>!
AutofillId!
Int
AutofillValue!
Drawable!
BlendMode!
ColorStateList!
PorterDuff.Mode!
Int
Int
Float
Int
Float
Rect!
Boolean
getClipBounds(outRect: Rect!)
Boolean
ContentCaptureSession!
CharSequence!
Context!
ContextMenu.ContextMenuInfo!
Boolean
java-static Int
getDefaultSize(size: Int, measureSpec: Int)
Display!
IntArray<Int>!
Bitmap!

This function is deprecated.

Int

This function is deprecated.

Int

This function is deprecated.

Unit
getDrawingRect(outRect: Rect!)
Long
Float
Int
Boolean
Boolean
Int
ArrayList<View!>!
getFocusables(direction: Int)
Unit
Drawable!
Int
BlendMode!
ColorStateList!
PorterDuff.Mode!
Boolean
getGlobalVisibleRect(r: Rect!, globalOffset: Point!)
Handler!
Float
Float
Float
Float
Runnable!
Boolean
Int
Unit
getHitRect(outRect: Rect!)
Int
Int
Drawable!
Drawable!
Int
Int
Int
Int
Boolean
KeyEvent.DispatcherState!
Int
Int
Int
ViewGroup.LayoutParams!
Int
Float
Int
Boolean
Unit
Unit
Unit
Matrix!
Int
Int
Int
Int
Int
Int
Int
Int
Int
Int
Int
Int
Int
View.OnFocusChangeListener!
Int
ViewOutlineProvider!
Int
Int
ViewOverlay!
Int
Int
Int
Int
Int
Int
ViewParent!
ViewParent!
Float
Float
PointerIcon!
(Mutable)List<Rect!>!
Array<String!>!
Resources!
Boolean
Int
Float
Int
AttachedSurfaceControl!
View!
WindowInsets!
Float
Float
Float
Float
Float
Int
Int
Int
Int
Int
Int
Int
Int
Int
Int
CharSequence!
StateListAnimator!
Int
Int
(Mutable)List<Rect!>!
Int

This function is deprecated.

Any!
Int
Int
CharSequence!
Int
Float
Int
TouchDelegate!
ArrayList<View!>!
Float
String!
Float
Float
Float
Long
Int
Int
Drawable!
Drawable!
Int
ViewTranslationResponse!
ViewTreeObserver!
Int
Int
Int
WindowId!
WindowInsetsController!
Int

This function is deprecated.

IBinder!
Int
Unit
Float
Float
Float
Boolean
Boolean
Boolean
Boolean
Boolean
Boolean
Boolean
Boolean
java-static View!
inflate(context: Context!, resource: Int, root: ViewGroup!)
Unit
invalidate(dirty: Rect!)

This function is deprecated.

Unit
Unit
Boolean
Boolean
Boolean
Boolean
Boolean
Boolean
Boolean
Boolean
Boolean
Boolean
Boolean

This function is deprecated.

Boolean
Boolean
Boolean
Boolean
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Boolean
Boolean
Boolean
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Boolean
Boolean
Boolean
Boolean
Boolean
Boolean
Boolean
Boolean
Boolean
Boolean
Boolean
Boolean
Boolean
Boolean
View!
keyboardNavigationClusterSearch(currentCluster: View!, direction: Int)
Unit
measure(widthMeasureSpec: Int, heightMeasureSpec: Int)
java-static IntArray<Int>!
mergeDrawableStates(baseState: IntArray!, additionalState: IntArray!)
Unit
Unit
Unit
Unit
WindowInsets!
Unit
Boolean
Boolean
Unit
Unit
InputConnection!
Unit
onCreateViewTranslationRequest(
    supportedFormats: IntArray!,
    requestsCollector: Consumer<ViewTranslationRequest!>!
)
Unit
onCreateVirtualViewTranslationRequests(
    virtualIds: LongArray!,
    supportedFormats: IntArray!,
    requestsCollector: Consumer<ViewTranslationRequest!>!
)
Unit
Boolean
Unit
onDraw(canvas: Canvas!)
Unit
Unit
Boolean
Unit
Unit
Unit
onFocusChanged(
    gainFocus: Boolean,
    direction: Int,
    previouslyFocusedRect: Rect!
)
Boolean
Unit
Boolean
Unit
Unit
Boolean
onKeyDown(keyCode: Int, event: KeyEvent!)
Boolean
onKeyLongPress(keyCode: Int, event: KeyEvent!)
Boolean
onKeyMultiple(keyCode: Int, repeatCount: Int, event: KeyEvent!)
Boolean
onKeyPreIme(keyCode: Int, event: KeyEvent!)
Boolean
onKeyShortcut(keyCode: Int, event: KeyEvent!)
Boolean
onKeyUp(keyCode: Int, event: KeyEvent!)
Unit
onOverScrolled(
    scrollX: Int,
    scrollY: Int,
    clampedX: Boolean,
    clampedY: Boolean
)
Unit
Unit
Unit
Unit
Unit
Unit
Unit
ContentInfo!
Unit
Unit
onRtlPropertiesChanged(layoutDirection: Int)
Parcelable!
Unit
onScreenStateChanged(screenState: Int)
Unit
onScrollCaptureSearch(
    localVisibleRect: Rect!,
    windowOffset: Point!,
    targets: Consumer<ScrollCaptureTarget!>!
)
Unit
onScrollChanged(l: Int, t: Int, oldl: Int, oldt: Int)
Boolean
onSetAlpha(alpha: Int)
Unit
onSizeChanged(w: Int, h: Int, oldw: Int, oldh: Int)
Unit
Boolean
Unit
Unit
Unit
Unit
onVisibilityChanged(changedView: View!, visibility: Int)
Unit
onWindowFocusChanged(hasWindowFocus: Boolean)
Unit

This function is deprecated.

Unit
Boolean
overScrollBy(
    deltaX: Int,
    deltaY: Int,
    scrollX: Int,
    scrollY: Int,
    scrollRangeX: Int,
    scrollRangeY: Int,
    maxOverScrollX: Int,
    maxOverScrollY: Int,
    isTouchEvent: Boolean
)
Boolean
performAccessibilityAction(action: Int, arguments: Bundle!)
Boolean
Boolean
performHapticFeedback(feedbackConstant: Int)
Boolean
ContentInfo!
Unit
playSoundEffect(soundConstant: Int)
Boolean
post(action: Runnable!)
Boolean
postDelayed(action: Runnable!, delayMillis: Long)
Unit
Unit
postInvalidateDelayed(delayMilliseconds: Long)
Unit
Unit
Unit
postOnAnimationDelayed(action: Runnable!, delayMillis: Long)
Unit
Unit
Boolean
Unit
Unit
Unit
Unit
Unit

This function is deprecated.

Boolean
Unit
Unit
Boolean
Unit
T!
<T : View?> requireViewById(id: Int)
Unit
java-static Int
resolveSize(size: Int, measureSpec: Int)
java-static Int
resolveSizeAndState(size: Int, measureSpec: Int, childMeasuredState: Int)
Unit
Unit
saveAttributeDataForStyleable(
    context: Context!,
    styleable: IntArray!,
    attrs: AttributeSet!,
    t: TypedArray!,
    defStyleAttr: Int,
    defStyleRes: Int
)
Unit
Unit
scheduleDrawable(who: Drawable!, what: Runnable!, when: Long)
Unit
scrollBy(x: Int, y: Int)
Unit
scrollTo(x: Int, y: Int)
Unit
Unit
Unit
setAccessibilityDataSensitive(accessibilityDataSensitive: Int)
Unit
Unit
Unit
Unit
setAccessibilityPaneTitle(accessibilityPaneTitle: CharSequence!)
Unit
Unit
Unit
setActivated(activated: Boolean)
Unit
setAllowClickWhenDisabled(clickableWhenDisabled: Boolean)
Unit
Unit
Unit
setAlpha(alpha: Float)
Unit
setAnimation(animation: Animation!)
Unit
Unit
Unit
setAutofillHints(autofillHints: Array<String!>!)
Unit
Unit
setBackground(background: Drawable!)
Unit
Unit

This function is deprecated.

Unit
Unit
Unit
Unit
Unit
setBottom(bottom: Int)
Unit
Unit
setClickable(clickable: Boolean)
Unit
setClipBounds(clipBounds: Rect!)
Unit
setClipToOutline(clipToOutline: Boolean)
Unit
Unit
setContentDescription(contentDescription: CharSequence!)
Unit
setContextClickable(contextClickable: Boolean)
Unit
setDefaultFocusHighlightEnabled(defaultFocusHighlightEnabled: Boolean)
Unit

This function is deprecated.

Unit

This function is deprecated.

Unit

This function is deprecated.

Unit
Unit
setElevation(elevation: Float)
Unit
setEnabled(enabled: Boolean)
Unit
Unit
Unit
setFitsSystemWindows(fitSystemWindows: Boolean)
Unit
setFocusable(focusable: Boolean)
Unit
setFocusableInTouchMode(focusableInTouchMode: Boolean)
Unit
setFocusedByDefault(isFocusedByDefault: Boolean)
Unit
Unit
setForeground(foreground: Drawable!)
Unit
Unit
Unit
Unit
setHandwritingBoundsOffsets(
    offsetLeft: Float,
    offsetTop: Float,
    offsetRight: Float,
    offsetBottom: Float
)
Unit
Unit
setHapticFeedbackEnabled(hapticFeedbackEnabled: Boolean)
Unit
setHasTransientState(hasTransientState: Boolean)
Unit
setHorizontalFadingEdgeEnabled(horizontalFadingEdgeEnabled: Boolean)
Unit
setHorizontalScrollBarEnabled(horizontalScrollBarEnabled: Boolean)
Unit
Unit
Unit
setHovered(hovered: Boolean)
Unit
setId(id: Int)
Unit
Unit
Unit
Unit
setIsCredential(isCredential: Boolean)
Unit
setIsHandwritingDelegate(isHandwritingDelegate: Boolean)
Unit
setKeepScreenOn(keepScreenOn: Boolean)
Unit
Unit
Unit
Unit
setLayerType(layerType: Int, paint: Paint!)
Unit
setLayoutDirection(layoutDirection: Int)
Unit
Unit
setLeft(left: Int)
Unit
setLeftTopRightBottom(left: Int, top: Int, right: Int, bottom: Int)
Unit
setLongClickable(longClickable: Boolean)
Unit
setMeasuredDimension(measuredWidth: Int, measuredHeight: Int)
Unit
setMinimumHeight(minHeight: Int)
Unit
setMinimumWidth(minWidth: Int)
Unit
Unit
setNextClusterForwardId(nextClusterForwardId: Int)
Unit
setNextFocusDownId(nextFocusDownId: Int)
Unit
setNextFocusForwardId(nextFocusForwardId: Int)
Unit
setNextFocusLeftId(nextFocusLeftId: Int)
Unit
setNextFocusRightId(nextFocusRightId: Int)
Unit
setNextFocusUpId(nextFocusUpId: Int)
Unit
Unit
Unit
Unit
Unit
Unit
Unit
Unit
Unit
Unit
Unit
Unit
setOnReceiveContentListener(
    mimeTypes: Array<String!>!,
    listener: OnReceiveContentListener!
)
Unit
Unit

This function is deprecated.

Unit
Unit
Unit
Unit
Unit
setOverScrollMode(overScrollMode: Int)
Unit
setPadding(left: Int, top: Int, right: Int, bottom: Int)
Unit
setPaddingRelative(start: Int, top: Int, end: Int, bottom: Int)
Unit
setPivotX(pivotX: Float)
Unit
setPivotY(pivotY: Float)
Unit
setPointerIcon(pointerIcon: PointerIcon!)
Unit
setPreferKeepClear(preferKeepClear: Boolean)
Unit
Unit
setPressed(pressed: Boolean)
Unit
setRenderEffect(renderEffect: RenderEffect!)
Unit
setRevealOnFocusHint(revealOnFocus: Boolean)
Unit
setRight(right: Int)
Unit
setRotation(rotation: Float)
Unit
setRotationX(rotationX: Float)
Unit
setRotationY(rotationY: Float)
Unit
Unit
Unit
setScaleX(scaleX: Float)
Unit
setScaleY(scaleY: Float)
Unit
setScreenReaderFocusable(screenReaderFocusable: Boolean)
Unit
setScrollBarDefaultDelayBeforeFade(
    scrollBarDefaultDelayBeforeFade: Int
)
Unit
setScrollBarFadeDuration(scrollBarFadeDuration: Int)
Unit
setScrollBarSize(scrollBarSize: Int)
Unit
Unit
Unit
Unit
setScrollContainer(isScrollContainer: Boolean)
Unit
setScrollIndicators(indicators: Int)
Unit
setScrollX(value: Int)
Unit
setScrollY(value: Int)
Unit
Unit
setSelected(selected: Boolean)
Unit
setSoundEffectsEnabled(soundEffectsEnabled: Boolean)
Unit
setStateDescription(stateDescription: CharSequence!)
Unit
Unit
Unit

This function is deprecated.

Unit
setTag(tag: Any!)
Unit
setTextAlignment(textAlignment: Int)
Unit
setTextDirection(textDirection: Int)
Unit
Unit
setTop(top: Int)
Unit
Unit
Unit
setTransitionName(transitionName: String!)
Unit
Unit
setTranslationX(translationX: Float)
Unit
setTranslationY(translationY: Float)
Unit
setTranslationZ(translationZ: Float)
Unit
setVerticalFadingEdgeEnabled(verticalFadingEdgeEnabled: Boolean)
Unit
setVerticalScrollBarEnabled(verticalScrollBarEnabled: Boolean)
Unit
Unit
Unit
Unit
Unit
setVisibility(visibility: Int)
Unit
setWillNotCacheDrawing(willNotCacheDrawing: Boolean)

This function is deprecated.

Unit
setWillNotDraw(willNotDraw: Boolean)
Unit
setX(x: Float)
Unit
setY(y: Float)
Unit
setZ(z: Float)
Boolean
ActionMode!
Unit
Boolean
startDrag(
    data: ClipData!,
    shadowBuilder: View.DragShadowBuilder!,
    myLocalState: Any!,
    flags: Int
)

This function is deprecated.

Boolean
startDragAndDrop(
    data: ClipData!,
    shadowBuilder: View.DragShadowBuilder!,
    myLocalState: Any!,
    flags: Int
)
Boolean
Unit
String!
Unit
Unit
Unit
Unit
Boolean
Boolean

This function is deprecated.

Boolean
From android.view.ViewGroup
Unit
Unit
addExtraDataToAccessibilityNodeInfo(
    info: AccessibilityNodeInfo!,
    extraDataKey: String!,
    arguments: Bundle!
)
Unit
addFocusables(views: ArrayList<View!>!, direction: Int, focusableMode: Int)
Unit
addKeyboardNavigationClusters(
    views: (Mutable)Collection<View!>!,
    direction: Int
)
Boolean
Unit
Unit
addView(child: View!)
Boolean
addViewInLayout(child: View!, index: Int, params: ViewGroup.LayoutParams!)
Unit
attachLayoutAnimationParameters(
    child: View!,
    params: ViewGroup.LayoutParams!,
    index: Int,
    count: Int
)
Unit
attachViewToParent(child: View!, index: Int, params: ViewGroup.LayoutParams!)
Unit
Boolean
Unit
Unit
childHasTransientStateChanged(
    child: View!,
    childHasTransientState: Boolean
)
Unit
Unit
Unit
Unit
Unit
debug(depth: Int)
Unit
Unit
Unit
detachViewsFromParent(start: Int, count: Int)
WindowInsets!
Boolean
Unit
Unit
dispatchCreateViewTranslationRequest(
    viewIds: (Mutable)Map<AutofillId!, LongArray!>!,
    supportedFormats: IntArray!,
    capability: TranslationCapability!,
    requests: (Mutable)List<ViewTranslationRequest!>!
)
Unit
Boolean
Unit
dispatchDraw(canvas: Canvas!)
Unit
Unit
Unit
Boolean
Boolean
Boolean
Boolean
Boolean
Boolean
Unit
Unit
Unit
Unit
Unit
Unit
dispatchScrollCaptureSearch(
    localVisibleRect: Rect!,
    windowOffset: Point!,
    targets: Consumer<ScrollCaptureTarget!>!
)
Unit
Unit
Unit
Unit
Unit

This function is deprecated.

Unit
Boolean
Boolean
Boolean
dispatchUnhandledMove(focused: View!, direction: Int)
Unit
dispatchVisibilityChanged(changedView: View!, visibility: Int)
Unit
Unit
Unit
WindowInsets!
dispatchWindowInsetsAnimationProgress(
    insets: WindowInsets!,
    runningAnimations: (Mutable)List<WindowInsetsAnimation!>!
)
WindowInsetsAnimation.Bounds!
Unit

This function is deprecated.

Unit
Boolean
drawChild(canvas: Canvas!, child: View!, drawingTime: Long)
Unit
Unit
View!
OnBackInvokedDispatcher!
Unit
findViewsWithText(
    outViews: ArrayList<View!>!,
    text: CharSequence!,
    flags: Int
)
View!
focusSearch(focused: View!, direction: Int)
Unit
Boolean
View!
getChildAt(index: Int)
Int
Int
getChildDrawingOrder(childCount: Int, drawingPosition: Int)
java-static Int
getChildMeasureSpec(spec: Int, padding: Int, childDimension: Int)
Boolean
Boolean
getChildVisibleRect(child: View!, r: Rect!, offset: Point!)
Boolean
Boolean
Int
View!
LayoutAnimationController!
Animation.AnimationListener!
Int
LayoutTransition!
Int
ViewGroupOverlay!
Int

This function is deprecated.

Boolean
Boolean
Boolean
Int
indexOfChild(child: View!)
Unit
invalidateChild(child: View!, dirty: Rect!)

This function is deprecated.

ViewParent!
invalidateChildInParent(location: IntArray!, dirty: Rect!)

This function is deprecated.

Boolean

This function is deprecated.

Boolean

This function is deprecated.

Boolean
Boolean

This function is deprecated.

Boolean
Boolean
Boolean
Unit
Unit
layout(l: Int, t: Int, r: Int, b: Int)
Unit
measureChild(
    child: View!,
    parentWidthMeasureSpec: Int,
    parentHeightMeasureSpec: Int
)
Unit
measureChildWithMargins(
    child: View!,
    parentWidthMeasureSpec: Int,
    widthUsed: Int,
    parentHeightMeasureSpec: Int,
    heightUsed: Int
)
Unit
measureChildren(widthMeasureSpec: Int, heightMeasureSpec: Int)
Unit
notifySubtreeAccessibilityStateChanged(
    child: View!,
    source: View!,
    changeType: Int
)
Unit
offsetDescendantRectToMyCoords(descendant: View!, rect: Rect!)
Unit
offsetRectIntoDescendantCoords(descendant: View!, rect: Rect!)
IntArray<Int>!
Unit
onDescendantInvalidated(child: View!, target: View!)
Boolean
Boolean
Boolean
onNestedFling(
    target: View!,
    velocityX: Float,
    velocityY: Float,
    consumed: Boolean
)
Boolean
onNestedPreFling(target: View!, velocityX: Float, velocityY: Float)
Boolean
onNestedPrePerformAccessibilityAction(
    target: View!,
    action: Int,
    args: Bundle!
)
Unit
onNestedPreScroll(target: View!, dx: Int, dy: Int, consumed: IntArray!)
Unit
onNestedScroll(
    target: View!,
    dxConsumed: Int,
    dyConsumed: Int,
    dxUnconsumed: Int,
    dyUnconsumed: Int
)
Unit
onNestedScrollAccepted(child: View!, target: View!, axes: Int)
Boolean
onRequestFocusInDescendants(direction: Int, previouslyFocusedRect: Rect!)
Boolean
PointerIcon!
onResolvePointerIcon(event: MotionEvent!, pointerIndex: Int)
Boolean
onStartNestedScroll(child: View!, target: View!, nestedScrollAxes: Int)
Unit
Unit
onViewAdded(child: View!)
Unit
Unit
Unit
Unit
Unit
removeDetachedView(child: View!, animate: Boolean)
Unit
removeView(view: View!)
Unit
removeViewAt(index: Int)
Unit
Unit
removeViews(start: Int, count: Int)
Unit
removeViewsInLayout(start: Int, count: Int)
Unit
requestChildFocus(child: View!, focused: View!)
Boolean
requestChildRectangleOnScreen(
    child: View!,
    rectangle: Rect!,
    immediate: Boolean
)
Unit
Boolean
requestFocus(direction: Int, previouslyFocusedRect: Rect!)
Boolean
Unit
Boolean
Unit
Unit
Unit

This function is deprecated.

Unit

This function is deprecated.

Unit

This function is deprecated.

Unit
Unit

This function is deprecated.

Unit
setClipChildren(clipChildren: Boolean)
Unit
setClipToPadding(clipToPadding: Boolean)
Unit
Unit
Unit
Unit
setLayoutMode(layoutMode: Int)
Unit
Unit
Unit
Unit
setPersistentDrawingCache(drawingCacheToKeep: Int)

This function is deprecated.

Unit
Unit
setTouchscreenBlocksFocus(touchscreenBlocksFocus: Boolean)
Unit
setTransitionGroup(isTransitionGroup: Boolean)
Unit
Boolean
showContextMenuForChild(originalView: View!)
ActionMode!
startActionModeForChild(
    originalView: View!,
    callback: ActionMode.Callback!
)
Unit
Unit
Unit
Unit

Public constructors

PreviewView

Added in 1.1.0
@UiThread
PreviewView(context: Context)

PreviewView

Added in 1.1.0
@UiThread
PreviewView(context: Context, attrs: AttributeSet?)

PreviewView

Added in 1.1.0
@UiThread
PreviewView(context: Context, attrs: AttributeSet?, defStyleAttr: Int)

PreviewView

Added in 1.1.0
@UiThread
PreviewView(
    context: Context,
    attrs: AttributeSet?,
    defStyleAttr: Int,
    defStyleRes: Int
)

Public functions

getBitmap

Added in 1.1.0
@UiThread
fun getBitmap(): Bitmap?

Returns a Bitmap representation of the content displayed on the PreviewView, or null if the camera preview hasn't started yet.

The returned Bitmap uses the ARGB_8888 pixel format and its dimensions are the same as this view's.

Do not invoke this method from a drawing method (onDraw for instance).

If an error occurs during the copy, an empty Bitmap will be returned.

If the preview hasn't started yet, the method may return null or an empty Bitmap. Use getPreviewStreamState to get the StreamState and wait for STREAMING to make sure the preview is started.

Returns
Bitmap?

A ARGB_8888Bitmap representing the content displayed on the PreviewView, or null if the camera preview hasn't started yet.

getController

Added in 1.1.0
@UiThread
fun getController(): CameraController?

Get the CameraController.

getImplementationMode

Added in 1.1.0
@UiThread
fun getImplementationMode(): PreviewView.ImplementationMode

Returns the ImplementationMode.

If nothing is set via setImplementationMode, the default value is PERFORMANCE.

getMeteringPointFactory

Added in 1.1.0
@UiThread
fun getMeteringPointFactory(): MeteringPointFactory

Gets the MeteringPointFactory for the camera currently connected to the PreviewView, if any.

The returned MeteringPointFactory is capable of creating MeteringPoints from (x, y) coordinates in the PreviewView. This conversion takes into account its ScaleType. The MeteringPointFactory is automatically adjusted if the PreviewView layout or the ScaleType changes.

The MeteringPointFactory returns invalid MeteringPoint if the preview is not ready, or the PreviewView dimension is zero. The invalid MeteringPoint will cause startFocusAndMetering to fail but it won't crash the application. Wait for the STREAMING state to make sure the preview is ready.

getOutputTransform

Added in 1.1.0
fun getOutputTransform(): OutputTransform?

Gets the OutputTransform associated with the PreviewView.

Returns a OutputTransform object that represents the transform being applied to the associated Preview use case. Returns null if the transform info is not ready. For example, when the associated Preview has not been bound or the PreviewView's layout is not ready.

PreviewView needs to be in COMPATIBLE mode for the transform to work correctly. For example, the returned OutputTransform may not respect the value of getMatrix when PERFORMANCE mode is used.

Returns
OutputTransform?

the transform applied on the preview by this PreviewView.

getPreviewStreamState

Added in 1.1.0
fun getPreviewStreamState(): LiveData<PreviewView.StreamState!>

Gets a LiveData for the preview StreamState.

There are two preview stream states, IDLE and STREAMING. IDLE indicates the preview is currently not visible and streaming is stopped. STREAMING means the preview is streaming or is about to start streaming. This state guarantees the preview is visible only when the ImplementationMode is COMPATIBLE. When in PERFORMANCE mode, it is possible the preview becomes visible slightly after the state changes to STREAMING.

Apps that require a precise signal for when the preview starts should set the implementation mode to COMPATIBLE.

Returns
LiveData<PreviewView.StreamState!>

A LiveData of the preview's StreamState. Apps can get the current state with getValue, or register an observer with observe .

getScaleType

Added in 1.1.0
@UiThread
fun getScaleType(): PreviewView.ScaleType

Returns the ScaleType currently applied to the preview.

The default value is FILL_CENTER.

Returns
PreviewView.ScaleType

The ScaleType currently applied to the preview.

getScreenFlash

Added in 1.4.0
@ExperimentalPreviewViewScreenFlash
@UiThread
fun getScreenFlash(): ImageCapture.ScreenFlash?

Returns an ImageCapture.ScreenFlash implementation based on the Window instance set via setScreenFlashWindow.

This API uses an internally managed ScreenFlashView to provide the ImageCapture.ScreenFlash implementation which can be passed to the setScreenFlash API. The following example shows the API usage.

mPreviewView.setScreenFlashWindow(activity.getWindow());
mImageCapture.setScreenFlash(mPreviewView.getScreenFlash());
mImageCapture.setFlashMode(ImageCapture.FLASH_MODE_SCREEN);
mImageCapture.takePhoto(mCameraExecutor, mOnImageSavedCallback);
Returns
ImageCapture.ScreenFlash?

An ImageCapture.ScreenFlash implementation provided by getScreenFlash which can be null if a non-null Window instance hasn't been set.

getSensorToViewTransform

Added in 1.4.0
@UiThread
fun getSensorToViewTransform(): Matrix?

Gets the transformation matrix from camera sensor to PreviewView.

The value is a mapping from sensor coordinates to PreviewView coordinates, which is, from the rect of SENSOR_INFO_ACTIVE_ARRAY_SIZE to the rect defined by (0, 0, PreviewView#getWidth(), PreviewView#getHeight()). The app can use the matrix to map the coordinates from one UseCase to another. For example, detecting face with ImageAnalysis, and then highlighting the face in PreviewView.

This method returns null if the transformation is not ready. It happens when PreviewView layout has not been measured, or the associated Preview use case is not yet bound to a camera. For the former case, the app can listen to the layout change via e.g. addOnLayoutChangeListener. For the latter case, the app wait until the Preview or CameraController is bound and the LifecycleOwner is in the STARTED state. The app should call this method to get the latest value before performing coordinates transformation.

The return value does not include the custom transform applied by the app via methods like setScaleX.

getSurfaceProvider

Added in 1.1.0
@UiThread
fun getSurfaceProvider(): Preview.SurfaceProvider

Gets a Preview.SurfaceProvider to be used with setSurfaceProvider. This allows the camera feed to start when the Preview use case is bound to a lifecycle.

The returned Preview.SurfaceProvider will provide a preview Surface to the camera that's either managed by a TextureView or SurfaceView depending on the ImplementationMode and the device's attributes (e.g. API level, camera hardware support level).

Returns
Preview.SurfaceProvider

A Preview.SurfaceProvider to attach to a Preview use case.

getViewPort

Added in 1.1.0
@UiThread
fun getViewPort(): ViewPort?

Gets a ViewPort based on the current status of PreviewView.

Returns a ViewPort instance based on the PreviewView's current width, height, layout direction, scale type and display rotation. By using the ViewPort, all the UseCases in the UseCaseGroup will have the same output image that also matches the aspect ratio of the PreviewView.

Returns
ViewPort?

null if the view is not currently attached or the view's width/height is zero.

getViewPort

Added in 1.1.0
@UiThread
fun getViewPort(targetRotation: Int): ViewPort?

Gets a ViewPort with custom target rotation.

Returns a ViewPort instance based on the PreviewView's current width, height, layout direction, scale type and the given target rotation.

Use this method if Preview's desired rotation is not the default display rotation. For example, when remote display is in use and the desired rotation for the remote display is based on the accelerometer reading. In that case, use android.view.OrientationEventListener to obtain the target rotation and create ViewPort as following:

ORIENTATION_UNKNOWN: orientation == -1

ROTATION_0: orientation >= 315 || orientation <45

ROTATION_90: orientation >= 225 &&orientation <315

ROTATION_180: orientation >= 135 &&orientation <225

ROTATION_270: orientation >= 45 &&orientation <135

Once the target rotation is obtained, use it with setTargetRotation to update the rotation. Example:

Preview preview = new Preview.Builder().setTargetRotation(targetRotation).build();
ViewPort viewPort = previewView.getViewPort(targetRotation);
UseCaseGroup useCaseGroup =
    new UseCaseGroup.Builder().setViewPort(viewPort).addUseCase(preview).build();
cameraProvider.bindToLifecycle(lifecycleOwner, cameraSelector, useCaseGroup);

Note that for non-display rotation to work, the mode must be set to COMPATIBLE.

Parameters
targetRotation: Int

A rotation value, expressed as one of ROTATION_0, ROTATION_90, ROTATION_180, or ROTATION_270.

Returns
ViewPort?

null if the view's width/height is zero.

onTouchEvent

fun onTouchEvent(event: MotionEvent): Boolean

performClick

fun performClick(): Boolean

setController

Added in 1.1.0
@UiThread
fun setController(cameraController: CameraController?): Unit

Sets the CameraController.

Once set, the controller will use PreviewView to display camera preview feed. It also uses the PreviewView's layout dimension to set the crop rect for all the use cases so that the output from other use cases match what the end user sees in PreviewView. It also enables features like tap-to-focus and pinch-to-zoom.

Setting it to null or to a different CameraController stops the previous CameraController from working. The previous CameraController will remain detached until it's set on the PreviewView again.

Throws
java.lang.IllegalArgumentException

If the CameraController's camera selector is unable to resolve a camera to be used for the enabled use cases.

See also
CameraController

setImplementationMode

Added in 1.1.0
@UiThread
fun setImplementationMode(
    implementationMode: PreviewView.ImplementationMode
): Unit

Sets the ImplementationMode for the PreviewView.

PreviewView displays the preview with a TextureView when the mode is COMPATIBLE, and tries to use a SurfaceView if it is PERFORMANCE when possible, which depends on the device's attributes (e.g. API level, camera hardware support level). If not set, the default mode is PERFORMANCE.

This method needs to be called before the Preview.SurfaceProvider is set on Preview. Once changed, Preview.SurfaceProvider needs to be set again. e.g. preview.setSurfaceProvider(previewView.getSurfaceProvider()).

setScaleType

Added in 1.1.0
@UiThread
fun setScaleType(scaleType: PreviewView.ScaleType): Unit

Applies a ScaleType to the preview.

If a CameraController is attached to PreviewView, the change will take immediate effect. It also takes immediate effect if getViewPort is not set in the bound UseCaseGroup. Otherwise, the UseCases need to be bound again with the latest value of getViewPort.

This value can also be set in the layout XML file via the app:scaleType attribute.

The default value is FILL_CENTER.

name app:scaleType

Parameters
scaleType: PreviewView.ScaleType

A ScaleType to apply to the preview.

setScreenFlashOverlayColor

Added in 1.4.0
@ExperimentalPreviewViewScreenFlash
fun setScreenFlashOverlayColor(color: @ColorInt Int): Unit

Sets the color of the top overlay view during screen flash.

Parameters
color: @ColorInt Int

The color value of the top overlay.

setScreenFlashWindow

Added in 1.4.0
@UiThread
fun setScreenFlashWindow(screenFlashWindow: Window?): Unit

Sets a Window instance for subsequent photo capture requests with FLASH_MODE_SCREEN set.

The calling of this API will take effect for FLASH_MODE_SCREEN only and the Window will be ignored for other flash modes. During screen flash photo capture, the window is used for the purpose of changing brightness.

If the implementation provided by the user is no longer valid (e.g. due to any android.app.Activity or android.view.View reference used in the implementation becoming invalid), user needs to re-set a new valid window or clear the previous one with setScreenFlashWindow(null), whichever appropriate.

For most app scenarios, a Window instance can be obtained from getWindow. In case of a fragment, getActivity can first be used to get the activity instance.

Parameters
screenFlashWindow: Window?

A Window instance that is used to change the brightness during screen flash photo capture.

Protected functions

onAttachedToWindow

protected fun onAttachedToWindow(): Unit

onDetachedFromWindow

protected fun onDetachedFromWindow(): Unit