java.lang.Object
- android.view.View
- - android.view.ViewGroup
  - - com.journeyapps.barcodescanner.CameraPreview

All Implemented Interfaces:

Drawable.Callback, AccessibilityEventSource, KeyEvent.Callback, ViewManager, ViewParent

Direct Known Subclasses:

BarcodeView
```
public class CameraPreview
extends ViewGroup
```
CameraPreview is a view that handles displaying of a camera preview on a SurfaceView. It is intended to be used as a base for realtime processing of camera images, e.g. barcode decoding or OCR, although none of this happens in CameraPreview itself. The camera is managed on a separate thread, using CameraInstance. Two methods MUST be called on CameraPreview to manage its state: 1. resume() - initialize the camera and start the preview. Call from the Activity's onResume(). 2. pause() - stop the preview and release any resources. Call from the Activity's onPause(). Startup sequence: 1. Create SurfaceView. 2. open camera. 2. layout this container, to get size 3. set display config, according to the container size 4. configure() 5. wait for preview size to be ready 6. set surface size according to preview size 7. set surface and start preview

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static interface CameraPreview.StateListener
- Nested classes/interfaces inherited from class android.view.ViewGroup
  ViewGroup.LayoutParams, ViewGroup.MarginLayoutParams, ViewGroup.OnHierarchyChangeListener
- Nested classes/interfaces inherited from class android.view.View
  View.AccessibilityDelegate, View.BaseSavedState, View.DragShadowBuilder, View.MeasureSpec, View.OnApplyWindowInsetsListener, View.OnAttachStateChangeListener, View.OnCapturedPointerListener, View.OnClickListener, View.OnContextClickListener, View.OnCreateContextMenuListener, View.OnDragListener, View.OnFocusChangeListener, View.OnGenericMotionListener, View.OnHoverListener, View.OnKeyListener, View.OnLayoutChangeListener, View.OnLongClickListener, View.OnScrollChangeListener, View.OnSystemUiVisibilityChangeListener, View.OnTouchListener, View.OnUnhandledKeyEventListener

Field Summary
- Fields inherited from class android.view.ViewGroup
  CLIP_TO_PADDING_MASK, FOCUS_AFTER_DESCENDANTS, FOCUS_BEFORE_DESCENDANTS, FOCUS_BLOCK_DESCENDANTS, LAYOUT_MODE_CLIP_BOUNDS, LAYOUT_MODE_OPTICAL_BOUNDS, PERSISTENT_ALL_CACHES, PERSISTENT_ANIMATION_CACHE, PERSISTENT_NO_CACHE, PERSISTENT_SCROLLING_CACHE
- Fields inherited from class android.view.View
  ACCESSIBILITY_LIVE_REGION_ASSERTIVE, ACCESSIBILITY_LIVE_REGION_NONE, ACCESSIBILITY_LIVE_REGION_POLITE, ALPHA, AUTOFILL_FLAG_INCLUDE_NOT_IMPORTANT_VIEWS, AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_DATE, AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_DAY, AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_MONTH, AUTOFILL_HINT_CREDIT_CARD_EXPIRATION_YEAR, AUTOFILL_HINT_CREDIT_CARD_NUMBER, AUTOFILL_HINT_CREDIT_CARD_SECURITY_CODE, AUTOFILL_HINT_EMAIL_ADDRESS, AUTOFILL_HINT_NAME, AUTOFILL_HINT_PASSWORD, AUTOFILL_HINT_PHONE, AUTOFILL_HINT_POSTAL_ADDRESS, AUTOFILL_HINT_POSTAL_CODE, AUTOFILL_HINT_USERNAME, AUTOFILL_TYPE_DATE, AUTOFILL_TYPE_LIST, AUTOFILL_TYPE_NONE, AUTOFILL_TYPE_TEXT, AUTOFILL_TYPE_TOGGLE, DRAG_FLAG_GLOBAL, DRAG_FLAG_GLOBAL_PERSISTABLE_URI_PERMISSION, DRAG_FLAG_GLOBAL_PREFIX_URI_PERMISSION, DRAG_FLAG_GLOBAL_URI_READ, DRAG_FLAG_GLOBAL_URI_WRITE, DRAG_FLAG_OPAQUE, DRAWING_CACHE_QUALITY_AUTO, DRAWING_CACHE_QUALITY_HIGH, DRAWING_CACHE_QUALITY_LOW, EMPTY_STATE_SET, ENABLED_FOCUSED_SELECTED_STATE_SET, ENABLED_FOCUSED_SELECTED_WINDOW_FOCUSED_STATE_SET, ENABLED_FOCUSED_STATE_SET, ENABLED_FOCUSED_WINDOW_FOCUSED_STATE_SET, ENABLED_SELECTED_STATE_SET, ENABLED_SELECTED_WINDOW_FOCUSED_STATE_SET, ENABLED_STATE_SET, ENABLED_WINDOW_FOCUSED_STATE_SET, FIND_VIEWS_WITH_CONTENT_DESCRIPTION, FIND_VIEWS_WITH_TEXT, FOCUS_BACKWARD, FOCUS_DOWN, FOCUS_FORWARD, FOCUS_LEFT, FOCUS_RIGHT, FOCUS_UP, FOCUSABLE, FOCUSABLE_AUTO, FOCUSABLES_ALL, FOCUSABLES_TOUCH_MODE, FOCUSED_SELECTED_STATE_SET, FOCUSED_SELECTED_WINDOW_FOCUSED_STATE_SET, FOCUSED_STATE_SET, FOCUSED_WINDOW_FOCUSED_STATE_SET, GONE, HAPTIC_FEEDBACK_ENABLED, IMPORTANT_FOR_ACCESSIBILITY_AUTO, IMPORTANT_FOR_ACCESSIBILITY_NO, IMPORTANT_FOR_ACCESSIBILITY_NO_HIDE_DESCENDANTS, IMPORTANT_FOR_ACCESSIBILITY_YES, IMPORTANT_FOR_AUTOFILL_AUTO, IMPORTANT_FOR_AUTOFILL_NO, IMPORTANT_FOR_AUTOFILL_NO_EXCLUDE_DESCENDANTS, IMPORTANT_FOR_AUTOFILL_YES, IMPORTANT_FOR_AUTOFILL_YES_EXCLUDE_DESCENDANTS, IMPORTANT_FOR_CONTENT_CAPTURE_AUTO, IMPORTANT_FOR_CONTENT_CAPTURE_NO, IMPORTANT_FOR_CONTENT_CAPTURE_NO_EXCLUDE_DESCENDANTS, IMPORTANT_FOR_CONTENT_CAPTURE_YES, IMPORTANT_FOR_CONTENT_CAPTURE_YES_EXCLUDE_DESCENDANTS, INVISIBLE, KEEP_SCREEN_ON, LAYER_TYPE_HARDWARE, LAYER_TYPE_NONE, LAYER_TYPE_SOFTWARE, LAYOUT_DIRECTION_INHERIT, LAYOUT_DIRECTION_LOCALE, LAYOUT_DIRECTION_LTR, LAYOUT_DIRECTION_RTL, MEASURED_HEIGHT_STATE_SHIFT, MEASURED_SIZE_MASK, MEASURED_STATE_MASK, MEASURED_STATE_TOO_SMALL, NO_ID, NOT_FOCUSABLE, OVER_SCROLL_ALWAYS, OVER_SCROLL_IF_CONTENT_SCROLLS, OVER_SCROLL_NEVER, PRESSED_ENABLED_FOCUSED_SELECTED_STATE_SET, PRESSED_ENABLED_FOCUSED_SELECTED_WINDOW_FOCUSED_STATE_SET, PRESSED_ENABLED_FOCUSED_STATE_SET, PRESSED_ENABLED_FOCUSED_WINDOW_FOCUSED_STATE_SET, PRESSED_ENABLED_SELECTED_STATE_SET, PRESSED_ENABLED_SELECTED_WINDOW_FOCUSED_STATE_SET, PRESSED_ENABLED_STATE_SET, PRESSED_ENABLED_WINDOW_FOCUSED_STATE_SET, PRESSED_FOCUSED_SELECTED_STATE_SET, PRESSED_FOCUSED_SELECTED_WINDOW_FOCUSED_STATE_SET, PRESSED_FOCUSED_STATE_SET, PRESSED_FOCUSED_WINDOW_FOCUSED_STATE_SET, PRESSED_SELECTED_STATE_SET, PRESSED_SELECTED_WINDOW_FOCUSED_STATE_SET, PRESSED_STATE_SET, PRESSED_WINDOW_FOCUSED_STATE_SET, ROTATION, ROTATION_X, ROTATION_Y, SCALE_X, SCALE_Y, SCREEN_STATE_OFF, SCREEN_STATE_ON, SCROLL_AXIS_HORIZONTAL, SCROLL_AXIS_NONE, SCROLL_AXIS_VERTICAL, SCROLL_INDICATOR_BOTTOM, SCROLL_INDICATOR_END, SCROLL_INDICATOR_LEFT, SCROLL_INDICATOR_RIGHT, SCROLL_INDICATOR_START, SCROLL_INDICATOR_TOP, SCROLLBAR_POSITION_DEFAULT, SCROLLBAR_POSITION_LEFT, SCROLLBAR_POSITION_RIGHT, SCROLLBARS_INSIDE_INSET, SCROLLBARS_INSIDE_OVERLAY, SCROLLBARS_OUTSIDE_INSET, SCROLLBARS_OUTSIDE_OVERLAY, SELECTED_STATE_SET, SELECTED_WINDOW_FOCUSED_STATE_SET, SOUND_EFFECTS_ENABLED, STATUS_BAR_HIDDEN, STATUS_BAR_VISIBLE, SYSTEM_UI_FLAG_FULLSCREEN, SYSTEM_UI_FLAG_HIDE_NAVIGATION, SYSTEM_UI_FLAG_IMMERSIVE, SYSTEM_UI_FLAG_IMMERSIVE_STICKY, SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN, SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION, SYSTEM_UI_FLAG_LAYOUT_STABLE, SYSTEM_UI_FLAG_LIGHT_NAVIGATION_BAR, SYSTEM_UI_FLAG_LIGHT_STATUS_BAR, SYSTEM_UI_FLAG_LOW_PROFILE, SYSTEM_UI_FLAG_VISIBLE, SYSTEM_UI_LAYOUT_FLAGS, TEXT_ALIGNMENT_CENTER, TEXT_ALIGNMENT_GRAVITY, TEXT_ALIGNMENT_INHERIT, TEXT_ALIGNMENT_TEXT_END, TEXT_ALIGNMENT_TEXT_START, TEXT_ALIGNMENT_VIEW_END, TEXT_ALIGNMENT_VIEW_START, TEXT_DIRECTION_ANY_RTL, TEXT_DIRECTION_FIRST_STRONG, TEXT_DIRECTION_FIRST_STRONG_LTR, TEXT_DIRECTION_FIRST_STRONG_RTL, TEXT_DIRECTION_INHERIT, TEXT_DIRECTION_LOCALE, TEXT_DIRECTION_LTR, TEXT_DIRECTION_RTL, TRANSLATION_X, TRANSLATION_Y, TRANSLATION_Z, VIEW_LOG_TAG, VISIBLE, WINDOW_FOCUSED_STATE_SET, X, Y, Z

Constructor Summary

Constructors
Constructor	Description
`CameraPreview(Context context)`
`CameraPreview(Context context, AttributeSet attrs)`
`CameraPreview(Context context, AttributeSet attrs, int defStyleAttr)`

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`addStateListener(CameraPreview.StateListener listener)`	Add a listener to be notified of changes to the preview state, as well as camera errors.
`protected Rect`	`calculateFramingRect(Rect container, Rect surface)`	Calculate framing rectangle, relative to the preview frame.
`protected Matrix`	`calculateTextureTransform(Size textureSize, Size previewSize)`	Calculate transformation for the TextureView.
`void`	`changeCameraParameters(CameraParametersCallback callback)`	Changes the settings for Camera.
`protected CameraInstance`	`createCameraInstance()`	Create a new CameraInstance.
`CameraInstance`	`getCameraInstance()`	Get the current CameraInstance.
`CameraSettings`	`getCameraSettings()`
`Rect`	`getFramingRect()`	The framing rectangle, relative to this view.
`Size`	`getFramingRectSize()`
`double`	`getMarginFraction()`
`Rect`	`getPreviewFramingRect()`	The framing rect, relative to the camera preview resolution.
`PreviewScalingStrategy`	`getPreviewScalingStrategy()`	Override this to specify a different preview scaling strategy.
`Size`	`getPreviewSize()`
`protected void`	`initializeAttributes(AttributeSet attrs)`	Initialize from XML attributes.
`protected boolean`	`isActive()`	Considered active if between resume() and pause().
`boolean`	`isCameraClosed()`
`boolean`	`isPreviewActive()`	The preview typically starts being active a while after calling resume(), and stops when calling pause().
`boolean`	`isUseTextureView()`
`protected void`	`onAttachedToWindow()`
`protected void`	`onLayout(boolean changed, int l, int t, int r, int b)`
`protected void`	`onRestoreInstanceState(Parcelable state)`
`protected Parcelable`	`onSaveInstanceState()`
`void`	`pause()`	Pause scanning and the camera preview.
`void`	`pauseAndWait()`	Pause scanning and preview; waiting for the Camera to be closed.
`protected void`	`previewStarted()`	Called when the preview is started.
`void`	`resume()`	Start the camera preview and decoding.
`void`	`setCameraSettings(CameraSettings cameraSettings)`	Set the CameraSettings.
`void`	`setFramingRectSize(Size framingRectSize)`	Set an exact size for the framing rectangle.
`void`	`setMarginFraction(double marginFraction)`	The the fraction of the width/height of view to be used as a margin for the framing rect.
`void`	`setPreviewScalingStrategy(PreviewScalingStrategy previewScalingStrategy)`	Override the preview scaling strategy.
`void`	`setTorch(boolean on)`	Call this on the main thread, while the preview is running.
`void`	`setUseTextureView(boolean useTextureView)`	Set to true to use TextureView instead of SurfaceView.

Methods inherited from class android.view.ViewGroup
addChildrenForAccessibility, addExtraDataToAccessibilityNodeInfo, addFocusables, addKeyboardNavigationClusters, addStatesFromChildren, addTouchables, addView, addView, addView, addView, addView, addViewInLayout, addViewInLayout, attachLayoutAnimationParameters, attachViewToParent, bringChildToFront, canAnimate, checkLayoutParams, childDrawableStateChanged, childHasTransientStateChanged, cleanupLayoutState, clearChildFocus, clearDisappearingChildren, clearFocus, debug, detachAllViewsFromParent, detachViewFromParent, detachViewFromParent, detachViewsFromParent, dispatchApplyWindowInsets, dispatchCapturedPointerEvent, dispatchConfigurationChanged, dispatchDisplayHint, dispatchDragEvent, dispatchDraw, dispatchDrawableHotspotChanged, dispatchFinishTemporaryDetach, dispatchFreezeSelfOnly, dispatchGenericFocusedEvent, dispatchGenericPointerEvent, dispatchHoverEvent, dispatchKeyEvent, dispatchKeyEventPreIme, dispatchKeyShortcutEvent, dispatchPointerCaptureChanged, dispatchProvideAutofillStructure, dispatchProvideStructure, dispatchRestoreInstanceState, dispatchSaveInstanceState, dispatchSetActivated, dispatchSetPressed, dispatchSetSelected, dispatchStartTemporaryDetach, dispatchSystemUiVisibilityChanged, dispatchThawSelfOnly, dispatchTouchEvent, dispatchTrackballEvent, dispatchUnhandledMove, dispatchVisibilityChanged, dispatchWindowFocusChanged, dispatchWindowInsetsAnimationEnd, dispatchWindowInsetsAnimationPrepare, dispatchWindowInsetsAnimationProgress, dispatchWindowInsetsAnimationStart, dispatchWindowSystemUiVisiblityChanged, dispatchWindowVisibilityChanged, drawableStateChanged, drawChild, endViewTransition, findFocus, findViewsWithText, focusableViewAvailable, focusSearch, gatherTransparentRegion, generateDefaultLayoutParams, generateLayoutParams, generateLayoutParams, getAccessibilityClassName, getChildAt, getChildCount, getChildDrawingOrder, getChildDrawingOrder, getChildMeasureSpec, getChildStaticTransformation, getChildVisibleRect, getClipChildren, getClipToPadding, getDescendantFocusability, getFocusedChild, getLayoutAnimation, getLayoutAnimationListener, getLayoutMode, getLayoutTransition, getNestedScrollAxes, getOverlay, getPersistentDrawingCache, getTouchscreenBlocksFocus, hasFocus, hasTransientState, indexOfChild, invalidateChild, invalidateChildInParent, isAlwaysDrawnWithCacheEnabled, isAnimationCacheEnabled, isChildrenDrawingOrderEnabled, isChildrenDrawnWithCacheEnabled, isLayoutSuppressed, isMotionEventSplittingEnabled, isTransitionGroup, jumpDrawablesToCurrentState, layout, measureChild, measureChildren, measureChildWithMargins, notifySubtreeAccessibilityStateChanged, offsetDescendantRectToMyCoords, offsetRectIntoDescendantCoords, onCreateDrawableState, onDescendantInvalidated, onDetachedFromWindow, onInterceptHoverEvent, onInterceptTouchEvent, onNestedFling, onNestedPreFling, onNestedPrePerformAccessibilityAction, onNestedPreScroll, onNestedScroll, onNestedScrollAccepted, onRequestFocusInDescendants, onRequestSendAccessibilityEvent, onResolvePointerIcon, onStartNestedScroll, onStopNestedScroll, onViewAdded, onViewRemoved, recomputeViewAttributes, removeAllViews, removeAllViewsInLayout, removeDetachedView, removeView, removeViewAt, removeViewInLayout, removeViews, removeViewsInLayout, requestChildFocus, requestChildRectangleOnScreen, requestDisallowInterceptTouchEvent, requestFocus, requestSendAccessibilityEvent, requestTransparentRegion, restoreDefaultFocus, scheduleLayoutAnimation, setAddStatesFromChildren, setAlwaysDrawnWithCacheEnabled, setAnimationCacheEnabled, setChildrenDrawingCacheEnabled, setChildrenDrawingOrderEnabled, setChildrenDrawnWithCacheEnabled, setClipChildren, setClipToPadding, setDescendantFocusability, setLayoutAnimation, setLayoutAnimationListener, setLayoutMode, setLayoutTransition, setMotionEventSplittingEnabled, setOnHierarchyChangeListener, setPersistentDrawingCache, setStaticTransformationsEnabled, setTouchscreenBlocksFocus, setTransitionGroup, setWindowInsetsAnimationCallback, shouldDelayChildPressedState, showContextMenuForChild, showContextMenuForChild, startActionModeForChild, startActionModeForChild, startLayoutAnimation, startViewTransition, suppressLayout, updateViewLayout

Methods inherited from class android.view.View
addFocusables, addOnAttachStateChangeListener, addOnLayoutChangeListener, addOnUnhandledKeyEventListener, animate, announceForAccessibility, autofill, autofill, awakenScrollBars, awakenScrollBars, awakenScrollBars, bringToFront, buildDrawingCache, buildDrawingCache, buildLayer, callOnClick, cancelDragAndDrop, cancelLongPress, cancelPendingInputEvents, canResolveLayoutDirection, canResolveTextAlignment, canResolveTextDirection, canScrollHorizontally, canScrollVertically, checkInputConnectionProxy, clearAnimation, combineMeasuredStates, computeHorizontalScrollExtent, computeHorizontalScrollOffset, computeHorizontalScrollRange, computeScroll, computeSystemWindowInsets, computeVerticalScrollExtent, computeVerticalScrollOffset, computeVerticalScrollRange, createAccessibilityNodeInfo, createContextMenu, destroyDrawingCache, dispatchGenericMotionEvent, dispatchNestedFling, dispatchNestedPreFling, dispatchNestedPrePerformAccessibilityAction, dispatchNestedPreScroll, dispatchNestedScroll, dispatchPopulateAccessibilityEvent, draw, drawableHotspotChanged, findViewById, findViewWithTag, fitSystemWindows, focusSearch, forceHasOverlappingRendering, forceLayout, generateViewId, getAccessibilityDelegate, getAccessibilityLiveRegion, getAccessibilityNodeProvider, getAccessibilityPaneTitle, getAccessibilityTraversalAfter, getAccessibilityTraversalBefore, getAlpha, getAnimation, getAnimationMatrix, getApplicationWindowToken, getAttributeResolutionStack, getAttributeSourceResourceMap, getAutofillHints, getAutofillId, getAutofillType, getAutofillValue, getBackground, getBackgroundTintBlendMode, getBackgroundTintList, getBackgroundTintMode, getBaseline, getBottom, getBottomFadingEdgeStrength, getBottomPaddingOffset, getCameraDistance, getClipBounds, getClipBounds, getClipToOutline, getContentCaptureSession, getContentDescription, getContext, getContextMenuInfo, getDefaultFocusHighlightEnabled, getDefaultSize, getDisplay, getDrawableState, getDrawingCache, getDrawingCache, getDrawingCacheBackgroundColor, getDrawingCacheQuality, getDrawingRect, getDrawingTime, getElevation, getExplicitStyle, getFilterTouchesWhenObscured, getFitsSystemWindows, getFocusable, getFocusables, getFocusedRect, getForeground, getForegroundGravity, getForegroundTintBlendMode, getForegroundTintList, getForegroundTintMode, getGlobalVisibleRect, getGlobalVisibleRect, getHandler, getHasOverlappingRendering, getHeight, getHitRect, getHorizontalFadingEdgeLength, getHorizontalScrollbarHeight, getHorizontalScrollbarThumbDrawable, getHorizontalScrollbarTrackDrawable, getId, getImportantForAccessibility, getImportantForAutofill, getImportantForContentCapture, getKeepScreenOn, getKeyDispatcherState, getLabelFor, getLayerType, getLayoutDirection, getLayoutParams, getLeft, getLeftFadingEdgeStrength, getLeftPaddingOffset, getLocalVisibleRect, getLocationInSurface, getLocationInWindow, getLocationOnScreen, getMatrix, getMeasuredHeight, getMeasuredHeightAndState, getMeasuredState, getMeasuredWidth, getMeasuredWidthAndState, getMinimumHeight, getMinimumWidth, getNextClusterForwardId, getNextFocusDownId, getNextFocusForwardId, getNextFocusLeftId, getNextFocusRightId, getNextFocusUpId, getOnFocusChangeListener, getOutlineAmbientShadowColor, getOutlineProvider, getOutlineSpotShadowColor, getOverScrollMode, getPaddingBottom, getPaddingEnd, getPaddingLeft, getPaddingRight, getPaddingStart, getPaddingTop, getParent, getParentForAccessibility, getPivotX, getPivotY, getPointerIcon, getResources, getRevealOnFocusHint, getRight, getRightFadingEdgeStrength, getRightPaddingOffset, getRootView, getRootWindowInsets, getRotation, getRotationX, getRotationY, getScaleX, getScaleY, getScrollBarDefaultDelayBeforeFade, getScrollBarFadeDuration, getScrollBarSize, getScrollBarStyle, getScrollIndicators, getScrollX, getScrollY, getSolidColor, getSourceLayoutResId, getStateDescription, getStateListAnimator, getSuggestedMinimumHeight, getSuggestedMinimumWidth, getSystemGestureExclusionRects, getSystemUiVisibility, getTag, getTag, getTextAlignment, getTextDirection, getTooltipText, getTop, getTopFadingEdgeStrength, getTopPaddingOffset, getTouchables, getTouchDelegate, getTransitionAlpha, getTransitionName, getTranslationX, getTranslationY, getTranslationZ, getUniqueDrawingId, getVerticalFadingEdgeLength, getVerticalScrollbarPosition, getVerticalScrollbarThumbDrawable, getVerticalScrollbarTrackDrawable, getVerticalScrollbarWidth, getViewTreeObserver, getVisibility, getWidth, getWindowAttachCount, getWindowId, getWindowInsetsController, getWindowSystemUiVisibility, getWindowToken, getWindowVisibility, getWindowVisibleDisplayFrame, getX, getY, getZ, hasExplicitFocusable, hasFocusable, hasNestedScrollingParent, hasOnClickListeners, hasOnLongClickListeners, hasOverlappingRendering, hasPointerCapture, hasWindowFocus, inflate, invalidate, invalidate, invalidate, invalidateDrawable, invalidateOutline, isAccessibilityFocused, isAccessibilityHeading, isActivated, isAttachedToWindow, isClickable, isContextClickable, isDirty, isDrawingCacheEnabled, isDuplicateParentStateEnabled, isEnabled, isFocusable, isFocusableInTouchMode, isFocused, isFocusedByDefault, isForceDarkAllowed, isHapticFeedbackEnabled, isHardwareAccelerated, isHorizontalFadingEdgeEnabled, isHorizontalScrollBarEnabled, isHovered, isImportantForAccessibility, isImportantForAutofill, isImportantForContentCapture, isInEditMode, isInLayout, isInTouchMode, isKeyboardNavigationCluster, isLaidOut, isLayoutDirectionResolved, isLayoutRequested, isLongClickable, isNestedScrollingEnabled, isOpaque, isPaddingOffsetRequired, isPaddingRelative, isPivotSet, isPressed, isSaveEnabled, isSaveFromParentEnabled, isScreenReaderFocusable, isScrollbarFadingEnabled, isScrollContainer, isSelected, isShowingLayoutBounds, isShown, isSoundEffectsEnabled, isTemporarilyDetached, isTextAlignmentResolved, isTextDirectionResolved, isVerticalFadingEdgeEnabled, isVerticalScrollBarEnabled, isVisibleToUserForAutofill, keyboardNavigationClusterSearch, measure, mergeDrawableStates, offsetLeftAndRight, offsetTopAndBottom, onAnimationEnd, onAnimationStart, onApplyWindowInsets, onCancelPendingInputEvents, onCapturedPointerEvent, onCheckIsTextEditor, onConfigurationChanged, onCreateContextMenu, onCreateInputConnection, onDisplayHint, onDragEvent, onDraw, onDrawForeground, onDrawScrollBars, onFilterTouchEventForSecurity, onFinishInflate, onFinishTemporaryDetach, onFocusChanged, onGenericMotionEvent, onHoverChanged, onHoverEvent, onInitializeAccessibilityEvent, onInitializeAccessibilityNodeInfo, onKeyDown, onKeyLongPress, onKeyMultiple, onKeyPreIme, onKeyShortcut, onKeyUp, onMeasure, onOverScrolled, onPointerCaptureChange, onPopulateAccessibilityEvent, onProvideAutofillStructure, onProvideAutofillVirtualStructure, onProvideContentCaptureStructure, onProvideStructure, onProvideVirtualStructure, onRtlPropertiesChanged, onScreenStateChanged, onScrollChanged, onSetAlpha, onSizeChanged, onStartTemporaryDetach, onTouchEvent, onTrackballEvent, onVisibilityAggregated, onVisibilityChanged, onWindowFocusChanged, onWindowSystemUiVisibilityChanged, onWindowVisibilityChanged, overScrollBy, performAccessibilityAction, performClick, performContextClick, performContextClick, performHapticFeedback, performHapticFeedback, performLongClick, performLongClick, playSoundEffect, post, postDelayed, postInvalidate, postInvalidate, postInvalidateDelayed, postInvalidateDelayed, postInvalidateOnAnimation, postInvalidateOnAnimation, postOnAnimation, postOnAnimationDelayed, refreshDrawableState, releasePointerCapture, removeCallbacks, removeOnAttachStateChangeListener, removeOnLayoutChangeListener, removeOnUnhandledKeyEventListener, requestApplyInsets, requestFitSystemWindows, requestFocus, requestFocus, requestFocusFromTouch, requestLayout, requestPointerCapture, requestRectangleOnScreen, requestRectangleOnScreen, requestUnbufferedDispatch, requestUnbufferedDispatch, requireViewById, resetPivot, resolveSize, resolveSizeAndState, restoreHierarchyState, saveAttributeDataForStyleable, saveHierarchyState, scheduleDrawable, scrollBy, scrollTo, sendAccessibilityEvent, sendAccessibilityEventUnchecked, setAccessibilityDelegate, setAccessibilityHeading, setAccessibilityLiveRegion, setAccessibilityPaneTitle, setAccessibilityTraversalAfter, setAccessibilityTraversalBefore, setActivated, setAlpha, setAnimation, setAnimationMatrix, setAutofillHints, setAutofillId, setBackground, setBackgroundColor, setBackgroundDrawable, setBackgroundResource, setBackgroundTintBlendMode, setBackgroundTintList, setBackgroundTintMode, setBottom, setCameraDistance, setClickable, setClipBounds, setClipToOutline, setContentCaptureSession, setContentDescription, setContextClickable, setDefaultFocusHighlightEnabled, setDrawingCacheBackgroundColor, setDrawingCacheEnabled, setDrawingCacheQuality, setDuplicateParentStateEnabled, setElevation, setEnabled, setFadingEdgeLength, setFilterTouchesWhenObscured, setFitsSystemWindows, setFocusable, setFocusable, setFocusableInTouchMode, setFocusedByDefault, setForceDarkAllowed, setForeground, setForegroundGravity, setForegroundTintBlendMode, setForegroundTintList, setForegroundTintMode, setHapticFeedbackEnabled, setHasTransientState, setHorizontalFadingEdgeEnabled, setHorizontalScrollBarEnabled, setHorizontalScrollbarThumbDrawable, setHorizontalScrollbarTrackDrawable, setHovered, setId, setImportantForAccessibility, setImportantForAutofill, setImportantForContentCapture, setKeepScreenOn, setKeyboardNavigationCluster, setLabelFor, setLayerPaint, setLayerType, setLayoutDirection, setLayoutParams, setLeft, setLeftTopRightBottom, setLongClickable, setMeasuredDimension, setMinimumHeight, setMinimumWidth, setNestedScrollingEnabled, setNextClusterForwardId, setNextFocusDownId, setNextFocusForwardId, setNextFocusLeftId, setNextFocusRightId, setNextFocusUpId, setOnApplyWindowInsetsListener, setOnCapturedPointerListener, setOnClickListener, setOnContextClickListener, setOnCreateContextMenuListener, setOnDragListener, setOnFocusChangeListener, setOnGenericMotionListener, setOnHoverListener, setOnKeyListener, setOnLongClickListener, setOnScrollChangeListener, setOnSystemUiVisibilityChangeListener, setOnTouchListener, setOutlineAmbientShadowColor, setOutlineProvider, setOutlineSpotShadowColor, setOverScrollMode, setPadding, setPaddingRelative, setPivotX, setPivotY, setPointerIcon, setPressed, setRevealOnFocusHint, setRight, setRotation, setRotationX, setRotationY, setSaveEnabled, setSaveFromParentEnabled, setScaleX, setScaleY, setScreenReaderFocusable, setScrollBarDefaultDelayBeforeFade, setScrollBarFadeDuration, setScrollbarFadingEnabled, setScrollBarSize, setScrollBarStyle, setScrollContainer, setScrollIndicators, setScrollIndicators, setScrollX, setScrollY, setSelected, setSoundEffectsEnabled, setStateDescription, setStateListAnimator, setSystemGestureExclusionRects, setSystemUiVisibility, setTag, setTag, setTextAlignment, setTextDirection, setTooltipText, setTop, setTouchDelegate, setTransitionAlpha, setTransitionName, setTransitionVisibility, setTranslationX, setTranslationY, setTranslationZ, setVerticalFadingEdgeEnabled, setVerticalScrollBarEnabled, setVerticalScrollbarPosition, setVerticalScrollbarThumbDrawable, setVerticalScrollbarTrackDrawable, setVisibility, setWillNotCacheDrawing, setWillNotDraw, setX, setY, setZ, showContextMenu, showContextMenu, startActionMode, startActionMode, startAnimation, startDrag, startDragAndDrop, startNestedScroll, stopNestedScroll, toString, transformMatrixToGlobal, transformMatrixToLocal, unscheduleDrawable, unscheduleDrawable, updateDragShadow, verifyDrawable, willNotCacheDrawing, willNotDraw

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface android.view.ViewParent
canResolveLayoutDirection, canResolveTextAlignment, canResolveTextDirection, createContextMenu, getLayoutDirection, getParent, getParentForAccessibility, getTextAlignment, getTextDirection, isLayoutDirectionResolved, isLayoutRequested, isTextAlignmentResolved, isTextDirectionResolved, keyboardNavigationClusterSearch, requestFitSystemWindows, requestLayout

- Constructor Detail
  - CameraPreview
```
public CameraPreview(Context context)
```
  - CameraPreview
```
public CameraPreview(Context context,
                     AttributeSet attrs)
```
  - CameraPreview
```
public CameraPreview(Context context,
                     AttributeSet attrs,
                     int defStyleAttr)
```
- Method Detail
  - onAttachedToWindow
```
protected void onAttachedToWindow()
```
    Overrides:
    
    onAttachedToWindow in class ViewGroup
  - initializeAttributes
```
protected void initializeAttributes(AttributeSet attrs)
```
    Initialize from XML attributes.
    
    Parameters:
    
    attrs - the attributes
  - addStateListener
```
public void addStateListener(CameraPreview.StateListener listener)
```
    Add a listener to be notified of changes to the preview state, as well as camera errors.
    
    Parameters:
    
    listener - the listener
  - setTorch
```
public void setTorch(boolean on)
```
    Call this on the main thread, while the preview is running.
    
    Parameters:
    
    on - true to turn on the torch
  - changeCameraParameters
```
public void changeCameraParameters(CameraParametersCallback callback)
```
    Changes the settings for Camera. Must be called after resume().
    
    Parameters:
    
    callback - CameraParametersCallback
  - setPreviewScalingStrategy
```
public void setPreviewScalingStrategy(PreviewScalingStrategy previewScalingStrategy)
```
    Override the preview scaling strategy.
    
    Parameters:
    
    previewScalingStrategy - null for the default
  - getPreviewScalingStrategy
```
public PreviewScalingStrategy getPreviewScalingStrategy()
```
    Override this to specify a different preview scaling strategy.
  - calculateTextureTransform
```
protected Matrix calculateTextureTransform(Size textureSize,
                                           Size previewSize)
```
    Calculate transformation for the TextureView. An identity matrix would cause the preview to be scaled up/down to fill the TextureView.
    
    Parameters:
    
    textureSize - the size of the textureView
    
    previewSize - the camera preview resolution
    
    Returns:
    
    the transform matrix for the TextureView
  - onLayout
```
protected void onLayout(boolean changed,
                        int l,
                        int t,
                        int r,
                        int b)
```
    Specified by:
    
    onLayout in class ViewGroup
  - getFramingRect
```
public Rect getFramingRect()
```
    The framing rectangle, relative to this view. Use to draw the rectangle. Will never be null while the preview is active.
    
    Returns:
    
    the framing rect, or null
    
    See Also:
    
    isPreviewActive()
  - getPreviewFramingRect
```
public Rect getPreviewFramingRect()
```
    The framing rect, relative to the camera preview resolution. Will never be null while the preview is active.
    
    Returns:
    
    the preview rect, or null
    
    See Also:
    
    isPreviewActive()
  - getPreviewSize
```
public Size getPreviewSize()
```
  - getCameraSettings
```
public CameraSettings getCameraSettings()
```
    Returns:
    
    the CameraSettings currently in use
  - setCameraSettings
```
public void setCameraSettings(CameraSettings cameraSettings)
```
    Set the CameraSettings. Use this to select a different camera, change exposure and torch settings, and some other options. This has no effect if the camera is already open.
    
    Parameters:
    
    cameraSettings - the new settings
  - resume
```
public void resume()
```
    Start the camera preview and decoding. Typically this should be called from the Activity's onResume() method. Call from UI thread only.
  - pause
```
public void pause()
```
    Pause scanning and the camera preview. Typically this should be called from the Activity's onPause() method. Call from UI thread only.
  - pauseAndWait
```
public void pauseAndWait()
```
    Pause scanning and preview; waiting for the Camera to be closed. This blocks the main thread.
  - getFramingRectSize
```
public Size getFramingRectSize()
```
  - setFramingRectSize
```
public void setFramingRectSize(Size framingRectSize)
```
    Set an exact size for the framing rectangle. It will be centered in the view.
    
    Parameters:
    
    framingRectSize - the size
  - getMarginFraction
```
public double getMarginFraction()
```
  - setMarginFraction
```
public void setMarginFraction(double marginFraction)
```
    The the fraction of the width/height of view to be used as a margin for the framing rect. This is ignored if framingRectSize is specified.
    
    Parameters:
    
    marginFraction - the fraction
  - isUseTextureView
```
public boolean isUseTextureView()
```
  - setUseTextureView
```
public void setUseTextureView(boolean useTextureView)
```
    Set to true to use TextureView instead of SurfaceView. Will only have an effect on API >= 14.
    
    Parameters:
    
    useTextureView - true to use TextureView.
  - isActive
```
protected boolean isActive()
```
    Considered active if between resume() and pause().
    
    Returns:
    
    true if active
  - createCameraInstance
```
protected CameraInstance createCameraInstance()
```
    Create a new CameraInstance. Override to use a custom CameraInstance.
    
    Returns:
    
    a new CameraInstance
  - previewStarted
```
protected void previewStarted()
```
    Called when the preview is started. Override this to start decoding work.
  - getCameraInstance
```
public CameraInstance getCameraInstance()
```
    Get the current CameraInstance. This may be null, and may change when pausing / resuming the preview. While the preview is active, getCameraInstance() will never be null.
    
    Returns:
    
    the current CameraInstance
    
    See Also:
    
    isPreviewActive()
  - isPreviewActive
```
public boolean isPreviewActive()
```
    The preview typically starts being active a while after calling resume(), and stops when calling pause().
    
    Returns:
    
    true if the preview is active
  - calculateFramingRect
```
protected Rect calculateFramingRect(Rect container,
                                    Rect surface)
```
    Calculate framing rectangle, relative to the preview frame. Note that the SurfaceView may be larger than the container. Override this for more control over the framing rect calculations.
    
    Parameters:
    
    container - this container, with left = top = 0
    
    surface - the SurfaceView, relative to this container
    
    Returns:
    
    the framing rect, relative to this container
  - onSaveInstanceState
```
protected Parcelable onSaveInstanceState()
```
    Overrides:
    
    onSaveInstanceState in class View
  - onRestoreInstanceState
```
protected void onRestoreInstanceState(Parcelable state)
```
    Overrides:
    
    onRestoreInstanceState in class View
  - isCameraClosed
```
public boolean isCameraClosed()
```
    Returns:
    
    true if the camera has been closed in a background thread.

Class CameraPreview

Nested Class Summary

Nested classes/interfaces inherited from class android.view.ViewGroup

Nested classes/interfaces inherited from class android.view.View

Field Summary

Fields inherited from class android.view.ViewGroup

Fields inherited from class android.view.View

Constructor Summary

Method Summary

Methods inherited from class android.view.ViewGroup

Methods inherited from class android.view.View

Methods inherited from class java.lang.Object

Methods inherited from interface android.view.ViewParent

Constructor Detail

CameraPreview

CameraPreview

CameraPreview

Method Detail

onAttachedToWindow

initializeAttributes

addStateListener

setTorch

changeCameraParameters

setPreviewScalingStrategy

getPreviewScalingStrategy

calculateTextureTransform

onLayout

getFramingRect

getPreviewFramingRect

getPreviewSize

getCameraSettings

setCameraSettings

resume

pause

pauseAndWait

getFramingRectSize

setFramingRectSize

getMarginFraction

setMarginFraction

isUseTextureView

setUseTextureView

isActive

createCameraInstance

previewStarted

getCameraInstance

isPreviewActive

calculateFramingRect

onSaveInstanceState

onRestoreInstanceState

isCameraClosed