PreviewView

public final class PreviewView
extends FrameLayout

java.lang.Object
↳	android.view.View
	↳	android.view.ViewGroup
		↳	android.widget.FrameLayout
			↳	androidx.camera.view.PreviewView

---

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 View.INVISIBLE or View.GONE) on top of it. When the SurfaceView is attached to the display window, it calls ViewParent.requestTransparentRegion(View) 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 ViewParent.requestTransparentRegion(View) 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.

Summary

Nested classes
enum	PreviewView.ImplementationMode The implementation mode of a PreviewView.
enum	PreviewView.ScaleType Options for scaling the preview vis-à-vis its container PreviewView.
enum	PreviewView.StreamState Definitions for the preview stream state.

Inherited constants
From class android.view.ViewGroup int CLIP_TO_PADDING_MASK int FOCUS_AFTER_DESCENDANTS int FOCUS_BEFORE_DESCENDANTS int FOCUS_BLOCK_DESCENDANTS int LAYOUT_MODE_CLIP_BOUNDS int LAYOUT_MODE_OPTICAL_BOUNDS int PERSISTENT_ALL_CACHES int PERSISTENT_ANIMATION_CACHE int PERSISTENT_NO_CACHE int PERSISTENT_SCROLLING_CACHE
From class android.view.View int ACCESSIBILITY_LIVE_REGION_ASSERTIVE int ACCESSIBILITY_LIVE_REGION_NONE int ACCESSIBILITY_LIVE_REGION_POLITE int AUTOFILL_FLAG_INCLUDE_NOT_IMPORTANT_VIEWS String AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_DATE String AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_DAY String AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_MONTH String AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_YEAR String AUTOFILL_HINT_CREDIT_CARD_NUMBER String AUTOFILL_HINT_CREDIT_CARD_SECURITY_CODE String AUTOFILL_HINT_EMAIL_ADDRESS String AUTOFILL_HINT_NAME String AUTOFILL_HINT_PASSWORD String AUTOFILL_HINT_PHONE String AUTOFILL_HINT_POSTAL_ADDRESS String AUTOFILL_HINT_POSTAL_CODE String AUTOFILL_HINT_USERNAME int AUTOFILL_TYPE_DATE int AUTOFILL_TYPE_LIST int AUTOFILL_TYPE_NONE int AUTOFILL_TYPE_TEXT int AUTOFILL_TYPE_TOGGLE int DRAG_FLAG_GLOBAL int DRAG_FLAG_GLOBAL_PERSISTABLE_URI_PERMISSION int DRAG_FLAG_GLOBAL_PREFIX_URI_PERMISSION int DRAG_FLAG_GLOBAL_URI_READ int DRAG_FLAG_GLOBAL_URI_WRITE int DRAG_FLAG_OPAQUE int DRAWING_CACHE_QUALITY_AUTO int DRAWING_CACHE_QUALITY_HIGH int DRAWING_CACHE_QUALITY_LOW int FIND_VIEWS_WITH_CONTENT_DESCRIPTION int FIND_VIEWS_WITH_TEXT int FOCUSABLE int FOCUSABLES_ALL int FOCUSABLES_TOUCH_MODE int FOCUSABLE_AUTO int FOCUS_BACKWARD int FOCUS_DOWN int FOCUS_FORWARD int FOCUS_LEFT int FOCUS_RIGHT int FOCUS_UP int GONE int HAPTIC_FEEDBACK_ENABLED int IMPORTANT_FOR_ACCESSIBILITY_AUTO int IMPORTANT_FOR_ACCESSIBILITY_NO int IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS int IMPORTANT_FOR_ACCESSIBILITY_YES int IMPORTANT_FOR_AUTOFILL_AUTO int IMPORTANT_FOR_AUTOFILL_NO int IMPORTANT_FOR_AUTOFILL_NO_EXCLUDE_DESCENDANTS int IMPORTANT_FOR_AUTOFILL_YES int IMPORTANT_FOR_AUTOFILL_YES_EXCLUDE_DESCENDANTS int IMPORTANT_FOR_CONTENT_CAPTURE_AUTO int IMPORTANT_FOR_CONTENT_CAPTURE_NO int IMPORTANT_FOR_CONTENT_CAPTURE_NO_EXCLUDE_DESCENDANTS int IMPORTANT_FOR_CONTENT_CAPTURE_YES int IMPORTANT_FOR_CONTENT_CAPTURE_YES_EXCLUDE_DESCENDANTS int INVISIBLE int KEEP_SCREEN_ON int LAYER_TYPE_HARDWARE int LAYER_TYPE_NONE int LAYER_TYPE_SOFTWARE int LAYOUT_DIRECTION_INHERIT int LAYOUT_DIRECTION_LOCALE int LAYOUT_DIRECTION_LTR int LAYOUT_DIRECTION_RTL int MEASURED_HEIGHT_STATE_SHIFT int MEASURED_SIZE_MASK int MEASURED_STATE_MASK int MEASURED_STATE_TOO_SMALL int NOT_FOCUSABLE int NO_ID int OVER_SCROLL_ALWAYS int OVER_SCROLL_IF_CONTENT_SCROLLS int OVER_SCROLL_NEVER int SCREEN_STATE_OFF int SCREEN_STATE_ON int SCROLLBARS_INSIDE_INSET int SCROLLBARS_INSIDE_OVERLAY int SCROLLBARS_OUTSIDE_INSET int SCROLLBARS_OUTSIDE_OVERLAY int SCROLLBAR_POSITION_DEFAULT int SCROLLBAR_POSITION_LEFT int SCROLLBAR_POSITION_RIGHT int SCROLL_AXIS_HORIZONTAL int SCROLL_AXIS_NONE int SCROLL_AXIS_VERTICAL int SCROLL_CAPTURE_HINT_AUTO int SCROLL_CAPTURE_HINT_EXCLUDE int SCROLL_CAPTURE_HINT_EXCLUDE_DESCENDANTS int SCROLL_CAPTURE_HINT_INCLUDE int SCROLL_INDICATOR_BOTTOM int SCROLL_INDICATOR_END int SCROLL_INDICATOR_LEFT int SCROLL_INDICATOR_RIGHT int SCROLL_INDICATOR_START int SCROLL_INDICATOR_TOP int SOUND_EFFECTS_ENABLED int STATUS_BAR_HIDDEN int STATUS_BAR_VISIBLE int SYSTEM_UI_FLAG_FULLSCREEN int SYSTEM_UI_FLAG_HIDE_NAVIGATION int SYSTEM_UI_FLAG_IMMERSIVE int SYSTEM_UI_FLAG_IMMERSIVE_STICKY int SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN int SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION int SYSTEM_UI_FLAG_LAYOUT_STABLE int SYSTEM_UI_FLAG_LIGHT_NAVIGATION_BAR int SYSTEM_UI_FLAG_LIGHT_STATUS_BAR int SYSTEM_UI_FLAG_LOW_PROFILE int SYSTEM_UI_FLAG_VISIBLE int SYSTEM_UI_LAYOUT_FLAGS int TEXT_ALIGNMENT_CENTER int TEXT_ALIGNMENT_GRAVITY int TEXT_ALIGNMENT_INHERIT int TEXT_ALIGNMENT_TEXT_END int TEXT_ALIGNMENT_TEXT_START int TEXT_ALIGNMENT_VIEW_END int TEXT_ALIGNMENT_VIEW_START int TEXT_DIRECTION_ANY_RTL int TEXT_DIRECTION_FIRST_STRONG int TEXT_DIRECTION_FIRST_STRONG_LTR int TEXT_DIRECTION_FIRST_STRONG_RTL int TEXT_DIRECTION_INHERIT int TEXT_DIRECTION_LOCALE int TEXT_DIRECTION_LTR int TEXT_DIRECTION_RTL String VIEW_LOG_TAG int VISIBLE

Inherited fields

From class android.view.View public static final Property<View, Float> ALPHA protected static final int[] EMPTY_STATE_SET protected static final int[] ENABLED_FOCUSED_SELECTED_STATE_SET protected static final int[] ENABLED_FOCUSED_SELECTED_WINDOW_FOCUSED_STATE_SET protected static final int[] ENABLED_FOCUSED_STATE_SET protected static final int[] ENABLED_FOCUSED_WINDOW_FOCUSED_STATE_SET protected static final int[] ENABLED_SELECTED_STATE_SET protected static final int[] ENABLED_SELECTED_WINDOW_FOCUSED_STATE_SET protected static final int[] ENABLED_STATE_SET protected static final int[] ENABLED_WINDOW_FOCUSED_STATE_SET protected static final int[] FOCUSED_SELECTED_STATE_SET protected static final int[] FOCUSED_SELECTED_WINDOW_FOCUSED_STATE_SET protected static final int[] FOCUSED_STATE_SET protected static final int[] FOCUSED_WINDOW_FOCUSED_STATE_SET protected static final int[] PRESSED_ENABLED_FOCUSED_SELECTED_STATE_SET protected static final int[] PRESSED_ENABLED_FOCUSED_SELECTED_WINDOW_FOCUSED_STATE_SET protected static final int[] PRESSED_ENABLED_FOCUSED_STATE_SET protected static final int[] PRESSED_ENABLED_FOCUSED_WINDOW_FOCUSED_STATE_SET protected static final int[] PRESSED_ENABLED_SELECTED_STATE_SET protected static final int[] PRESSED_ENABLED_SELECTED_WINDOW_FOCUSED_STATE_SET protected static final int[] PRESSED_ENABLED_STATE_SET protected static final int[] PRESSED_ENABLED_WINDOW_FOCUSED_STATE_SET protected static final int[] PRESSED_FOCUSED_SELECTED_STATE_SET protected static final int[] PRESSED_FOCUSED_SELECTED_WINDOW_FOCUSED_STATE_SET protected static final int[] PRESSED_FOCUSED_STATE_SET protected static final int[] PRESSED_FOCUSED_WINDOW_FOCUSED_STATE_SET protected static final int[] PRESSED_SELECTED_STATE_SET protected static final int[] PRESSED_SELECTED_WINDOW_FOCUSED_STATE_SET protected static final int[] PRESSED_STATE_SET protected static final int[] PRESSED_WINDOW_FOCUSED_STATE_SET public static final Property<View, Float> ROTATION public static final Property<View, Float> ROTATION_X public static final Property<View, Float> ROTATION_Y public static final Property<View, Float> SCALE_X public static final Property<View, Float> SCALE_Y protected static final int[] SELECTED_STATE_SET protected static final int[] SELECTED_WINDOW_FOCUSED_STATE_SET public static final Property<View, Float> TRANSLATION_X public static final Property<View, Float> TRANSLATION_Y public static final Property<View, Float> TRANSLATION_Z protected static final int[] WINDOW_FOCUSED_STATE_SET public static final Property<View, Float> X public static final Property<View, Float> Y public static final Property<View, Float> Z

Public constructors
PreviewView(Context context)
PreviewView(Context context, AttributeSet attrs)
PreviewView(Context context, AttributeSet attrs, int defStyleAttr)
PreviewView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes)

Public methods
Bitmap	getBitmap() Returns a Bitmap representation of the content displayed on the PreviewView, or null if the camera preview hasn't started yet.
<a href="/refer