# Class VisionCameraView<T>

java.lang.Object
com.codename1.ui.Component
com.codename1.ui.Container
com.codename1.ai.vision.VisionCameraView<T>

Type Parameters:
  `T` - the analyzer's result type

All Implemented Interfaces:
  `Animation, Editable, StyleListener, AutoCloseable, Iterable<Component>`

public class VisionCameraView<T> extends Container implements AutoCloseable

A live camera preview that runs an analyzer over its frames.

This is the whole camera-to-analyzer pipeline as one component: it opens the camera when it is shown, streams frames into the analyzer with keep-only-the-newest backpressure, delivers results on the EDT, and releases the camera when the form is left. Add it to a form and implement the listener; there is no session, frame listener, or `VisionImage` conversion to write.

    FaceDetector detector = new FaceDetector();
    VisionCameraView<Face[]> view = new VisionCameraView<Face[]>(detector);
    view.setFacing(CameraFacing.FRONT);
    view.setListener(new VisionPipelineListener<Face[]>() {
        public void result(Face[] faces, VisionImage source) {
            countLabel.setText(faces.length + " face(s)");
        }
        public void error(Throwable error) {
            Log.e(error);
        }
    });

    Form form = new Form("Faces", new BorderLayout());
    form.add(BorderLayout.CENTER, view);
    form.add(BorderLayout.SOUTH, countLabel);
    form.show();

The analyzer is supplied by the caller rather than named by a feature constant, which is deliberate: the build pipeline decides which native vision dependency to package from the analyzer classes an application references, so constructing the analyzer in application code is what keeps a face-detection app from also carrying the barcode and pose models.

The preview is a native view. Codename One components cannot be painted over it on every platform -- iOS renders native peers behind the Codename One layer, Android renders them in front -- so put a scanner's reticle, hints, and buttons around the preview rather than on top of it. Result geometry such as `Face.getBounds()` can still be drawn in a component beside the preview using `VisionRect.toBounds(com.codename1.ui.Component)`.

One camera session may be open at a time, so a second view (or a `Capture` call) while this one is showing reports an error to the listener instead of stealing the hardware.

- ## Field Summary

  ### Fields inherited from class Component

  `BASELINE, BOTTOM, BRB_CENTER_OFFSET, BRB_CONSTANT_ASCENT, BRB_CONSTANT_DESCENT, BRB_OTHER, CENTER, CROSSHAIR_CURSOR, DEFAULT_CURSOR, DRAG_REGION_IMMEDIATELY_DRAG_X, DRAG_REGION_IMMEDIATELY_DRAG_XY, DRAG_REGION_IMMEDIATELY_DRAG_Y, DRAG_REGION_LIKELY_DRAG_X, DRAG_REGION_LIKELY_DRAG_XY, DRAG_REGION_LIKELY_DRAG_Y, DRAG_REGION_NOT_DRAGGABLE, DRAG_REGION_POSSIBLE_DRAG_X, DRAG_REGION_POSSIBLE_DRAG_XY, DRAG_REGION_POSSIBLE_DRAG_Y, E_RESIZE_CURSOR, HAND_CURSOR, LEFT, MOVE_CURSOR, N_RESIZE_CURSOR, NE_RESIZE_CURSOR, NW_RESIZE_CURSOR, RIGHT, S_RESIZE_CURSOR, SE_RESIZE_CURSOR, SW_RESIZE_CURSOR, TEXT_CURSOR, TOP, W_RESIZE_CURSOR, WAIT_CURSOR`

- ## Constructor Summary

  Constructors
  Constructor
  Description
  `VisionCameraView(VisionAnalyzer<T> analyzer)`
  Creates a view that runs `analyzer` over the back camera.

- ## Method Summary

  Modifier and Type
  Method
  Description
  `void`
  `close()`
  Releases the camera and the analyzer.
  `protected void`
  `deinitialize()`
  Releases the camera when the view stops being shown.
  `CameraFacing`
  `getFacing()`
  `VisionPipelineListener<T>`
  `getListener()`
  `int`
  `getMaxFps()`
  `ScaleType`
  `getScaleType()`
  `CameraSession`
  `getSession()`
  The open camera session, for torch, zoom, focus, or a still capture.
  `protected void`
  `initComponent()`
  Opens the camera when the view becomes part of a shown form.
  `boolean`
  `isRunning()`
  `boolean`
  `isSupported()`
  Whether the current platform can open a camera and run this view's analyzer.
  `void`
  `setFacing(CameraFacing value)`
  Selects which camera to open.
  `void`
  `setListener(VisionPipelineListener<T> value)`
  Installs the callback for analysis results and recoverable failures.
  `void`
  `setMaxFps(int value)`
  Caps how many frames per second reach the analyzer.
  `void`
  `setScaleType(ScaleType value)`
  How the preview is fitted into this component's bounds.
  `void`
  `setTorchEnabled(boolean on)`
  Turns the torch on or off, when the open camera has one.
  `void`
  `start()`
  Opens the camera and starts analyzing.
  `void`
  `stop()`
  Stops analyzing and releases the camera, leaving the analyzer usable.

  ### Methods inherited from class Container

  `add, add, add, add, add, add, addAll, addComponent, addComponent, addComponent, addComponent, animateHierarchy, animateHierarchyAndWait, animateHierarchyFade, animateHierarchyFadeAndWait, animateLayout, animateLayoutAndWait, animateLayoutFade, animateLayoutFadeAndWait, animateUnlayout, animateUnlayoutAndWait, applyRTL, calcPreferredSize, cancelRepaints, clearClientProperties, constrainHeightWhenScrollable, constrainWidthWhenScrollable, contains, createAnimateHierarchy, createAnimateHierarchyFade, createAnimateLayout, createAnimateLayoutFade, createAnimateLayoutFadeAndWait, createAnimateMotion, createAnimateUnlayout, createReplaceTransition, dragInitiated, drop, encloseIn, encloseIn, findDropTargetAt, findFirstFocusable, fireClicked, flushReplace, forceRevalidate, getBottomGap, getChildrenAsList, getClosestComponentTo, getComponentAt, getComponentAt, getComponentCount, getComponentIndex, getGridPosX, getGridPosY, getLayout, getLayoutHeight, getLayoutWidth, getLeadComponent, getLeadParent, getResponderAt, getSafeAreaRoot, getScrollIncrement, getSideGap, getUIManager, initLaf, invalidate, isEnabled, isSafeArea, isSafeAreaRoot, isScrollableX, isScrollableY, isSelectableInteraction, isSurface, iterator, iterator, keyPressed, keyReleased, layoutContainer, morph, morphAndWait, paint, paintComponentBackground, paintGlass, paramString, pointerPressed, refreshTheme, removeAll, removeComponent, replace, replace, replaceAndWait, replaceAndWait, replaceAndWait, revalidate, revalidateLater, revalidateWithAnimationSafety, scrollComponentToVisible, setCellRenderer, setEnabled, setLayout, setLeadComponent, setSafeArea, setSafeAreaRoot, setScrollable, setScrollableX, setScrollableY, setScrollIncrement, setShouldCalcPreferredSize, setShouldLayout, setUIManager, updateTabIndices`

  ### Methods inherited from class Component

  `accessibilityChanged, accessibilityChanged, addContextMenuListener, addDragFinishedListener, addDragOverListener, addDropListener, addFocusListener, addLongPressListener, addMouseWheelListener, addPointerDraggedListener, addPointerPressedListener, addPointerReleasedListener, addPullToRefresh, addScrollListener, addStateChangeListener, addStylusListener, animate, announceForAccessibility, bindProperty, blocksSideSwipe, calcScrollSize, consumesRawTextInput, contains, containsOrOwns, createStyleAnimation, deinitializeCustomStyle, dragEnter, dragExit, dragFinished, draggingOver, drawDraggedImage, focusGained, focusLost, getAbsoluteX, getAbsoluteY, getAccessibilityNode, getAccessibilityText, getAllStyles, getAnimationManager, getBaseline, getBaselineResizeBehavior, getBindablePropertyNames, getBindablePropertyTypes, getBorder, getBoundPropertyValue, getBounds, getBounds, getClientProperty, getCloudBoundProperty, getCloudDestinationProperty, getComponentForm, getComponentState, getCursor, getDefaultDragTransparency, getDirtyRegion, getDisabledStyle, getDraggedx, getDraggedy, getDragImage, getDragRegionStatus, getDragSpeed, getDragTransparency, getEditingDelegate, getHeight, getInlineAllStyles, getInlineDisabledStyles, getInlinePressedStyles, getInlineSelectedStyles, getInlineStylesTheme, getInlineUnselectedStyles, getInnerHeight, getInnerPreferredH, getInnerPreferredW, getInnerWidth, getInnerX, getInnerY, getLabelForComponent, getName, getNativeOverlay, getNextFocusDown, getNextFocusLeft, getNextFocusRight, getNextFocusUp, getOuterHeight, getOuterPreferredH, getOuterPreferredW, getOuterWidth, getOuterX, getOuterY, getOwner, getParent, getPreferredH, getPreferredSize, getPreferredSizeStr, getPreferredTabIndex, getPreferredW, getPressedStyle, getPropertyNames, getPropertyTypeNames, getPropertyTypes, getPropertyValue, getSameHeight, getSameWidth, getScrollable, getScrollAnimationSpeed, getScrollDimension, getScrollOpacity, getScrollOpacityChangeSpeed, getScrollX, getScrollY, getSelectCommandText, getSelectedRect, getSelectedStyle, getSemantics, getStyle, getTabIndex, getTensileLength, getTextSelectionSupport, getTooltip, getUIID, getUnselectedStyle, getVisibleBounds, getVisibleBounds, getWidth, getX, getY, growShrink, handlesInput, hasFixedPreferredSize, hasFocus, hideNativeOverlay, initCustomStyle, initDisabledStyle, initPressedStyle, initSelectedStyle, initUnselectedStyle, installDefaultPainter, isAlwaysTensile, isBlockLead, isCellRenderer, isChildOf, isDragActivated, isDragAndDropOperation, isDraggable, isDragRegion, isDropTarget, isEditable, isEditing, isFlatten, isFocusable, isGrabsPointerEvents, isHidden, isHidden, isHideInLandscape, isHideInPortrait, isHScrollThumbGrabbed, isHScrollThumbHover, isIgnorePointerEvents, isInClippingRegion, isInitialized, isOpaque, isOwnedBy, isPinchBlocksDragAndDrop, isRippleEffect, isRTL, isScrollable, isScrollVisible, isSetCursorSupported, isSmoothScrolling, isSnapToGrid, isStickyDrag, isTactileTouch, isTactileTouch, isTensileDragEnabled, isTraversable, isVisible, isVScrollThumbGrabbed, isVScrollThumbHover, keyRepeated, laidOut, longKeyPress, longPointerPress, onScrollX, onScrollY, onSetFocusable, paintBackground, paintBackgrounds, paintBorder, paintBorderBackground, paintComponent, paintComponent, paintIntersectingComponentsAbove, paintLock, paintLockRelease, paintRippleOverlay, paintScrollbars, paintScrollbarX, paintScrollbarY, paintShadows, parsePreferredSize, pinch, pinch, pinchReleased, pointerDragged, pointerDragged, pointerHover, pointerHoverPressed, pointerHoverReleased, pointerPressed, pointerReleased, pointerReleased, putClientProperty, refreshTheme, refreshTheme, remove, removeContextMenuListener, removeDragFinishedListener, removeDragOverListener, removeDropListener, removeFocusListener, removeLongPressListener, removeMouseWheelListener, removePointerDraggedListener, removePointerPressedListener, removePointerReleasedListener, removeScrollListener, removeStateChangeListener, removeStylusListener, repaint, repaint, requestFocus, resetFocusable, respondsToPointerEvents, rotation, scrollRectToVisible, scrollRectToVisible, setAccessibilityText, setAlwaysTensile, setBlockLead, setBoundPropertyValue, setCloudBoundProperty, setCloudDestinationProperty, setComponentState, setCursor, setDefaultDragTransparency, setDirtyRegion, setDisabledStyle, setDraggable, setDragTransparency, setDropTarget, setEditingDelegate, setFlatten, setFocus, setFocusable, setGrabsPointerEvents, setHandlesInput, setHeight, setHidden, setHidden, setHideInLandscape, setHideInPortrait, setHorizontalScrollBounds, setIgnorePointerEvents, setInitialized, setInlineAllStyles, setInlineDisabledStyles, setInlinePressedStyles, setInlineSelectedStyles, setInlineStylesTheme, setInlineUnselectedStyles, setIsScrollVisible, setLabelForComponent, setName, setNextFocusDown, setNextFocusLeft, setNextFocusRight, setNextFocusUp, setOpaque, setOwner, setPinchBlocksDragAndDrop, setPreferredH, setPreferredSize, setPreferredSizeStr, setPreferredTabIndex, setPreferredW, setPressedStyle, setPropertyValue, setPullToRefresh, setRippleEffect, setRTL, setSameHeight, setSameSize, setSameWidth, setScrollAnimationSpeed, setScrollOpacityChangeSpeed, setScrollSize, setScrollVisible, setScrollX, setScrollY, setSelectCommandText, setSelectedStyle, setSize, setSmoothScrolling, setSnapToGrid, setTabIndex, setTactileTouch, setTensileDragEnabled, setTensileLength, setTooltip, setTraversable, setUIID, setUIID, setUIIDFinal, setUnselectedStyle, setVerticalScrollBounds, setVisible, setWidth, setX, setY, shouldBlockSideSwipe, shouldBlockSideSwipeLeft, shouldBlockSideSwipeRight, shouldRenderComponentSelection, showNativeOverlay, startEditingAsync, stopEditing, stripMarginAndPadding, styleChanged, toImage, toString, unbindProperty, updateNativeOverlay, visibleBoundsContains`

  ### Methods inherited from class Object

  `clone, equals, getClass, hashCode, notify, notifyAll, wait, wait, wait`

  ### Methods inherited from interface Iterable

  `forEach`

- ## Constructor Details

  - ### VisionCameraView

    public VisionCameraView(VisionAnalyzer<T> analyzer)

    Creates a view that runs `analyzer` over the back camera.

    The view borrows the analyzer: leaving the form releases the camera but keeps the analyzer usable, and `close()` releases it for good.

    Parameters:
      `analyzer` - the reusable analyzer to run over each frame
    Throws:
      `NullPointerException` - if `analyzer` is `null`

- ## Method Details

  - ### isSupported

    public boolean isSupported()
    Whether the current platform can open a camera and run this view's analyzer. Check this before showing the view: a target without either piece reports failures through the listener rather than throwing.
    Returns:
      `true` when both the camera and the analyzer are available

  - ### setFacing

    public void setFacing(CameraFacing value)

    Selects which camera to open. Takes effect the next time the view is shown; the default is `CameraFacing.BACK`.

    A front camera's preview is requested mirrored, the way a selfie view behaves. The simulator honors that; the iOS and Android previews do not mirror yet. Note also that a device without the requested camera falls back to whatever it has, and the mirroring follows the camera that actually opened rather than the one asked for.

    Parameters:
      `value` - the camera to prefer, or `null` for the back camera

  - ### getFacing

    public CameraFacing getFacing()
    Returns:
      the camera this view opens

  - ### setMaxFps

    public void setMaxFps(int value)
    Caps how many frames per second reach the analyzer. Frames arriving while an analysis is in flight are dropped in favor of the newest one regardless of this value, so the cap mainly saves the camera the work of producing frames nothing will read. The default is 10.
    Parameters:
      `value` - frames per second, or `0` for uncapped

  - ### getMaxFps

    public int getMaxFps()
    Returns:
      the frame rate cap, or `0` when uncapped

  - ### setScaleType

    public void setScaleType(ScaleType value)

    How the preview is fitted into this component's bounds. The default is `ScaleType.CROP`, which fills the view the way a camera app does.

    The simulator honors every mode. The iOS and Android previews render fixed at fill-and-crop today, because neither port implements the scaling hook yet, so a non-default mode is a request those targets currently ignore rather than a promise.

    Parameters:
      `value` - the scaling to apply, or `null` for the default

  - ### getScaleType

    public ScaleType getScaleType()
    Returns:
      how the preview is fitted into this component's bounds

  - ### setListener

    public void setListener(VisionPipelineListener<T> value)
    Installs the callback for analysis results and recoverable failures. Both are delivered on the EDT.
    Parameters:
      `value` - the listener, or `null` to stop receiving results

  - ### getListener

    public VisionPipelineListener<T> getListener()
    Returns:
      the installed result listener, or `null`

  - ### getSession

    public CameraSession getSession()
    The open camera session, for torch, zoom, focus, or a still capture.
    Returns:
      the session while the view is showing, or `null`

  - ### setTorchEnabled

    public void setTorchEnabled(boolean on)
    Turns the torch on or off, when the open camera has one. A camera without a flash ignores this.
    Parameters:
      `on` - whether the torch should be lit

  - ### isRunning

    public boolean isRunning()
    Returns:
      `true` while the camera is open and frames are flowing

  - ### start

    public void start()
    Opens the camera and starts analyzing. Called automatically when the view is shown; calling it again while running does nothing.

  - ### stop

    public void stop()
    Stops analyzing and releases the camera, leaving the analyzer usable. Called automatically when the view stops being shown.

  - ### close

    public void close()
    Releases the camera and the analyzer. Use this when the view will not be shown again; simply navigating to another form already releases the camera. Calling it more than once has no effect.
    Specified by:
      `close` in interface `AutoCloseable`

  - ### initComponent

    protected void initComponent()
    Opens the camera when the view becomes part of a shown form.
    Overrides:
      `initComponent` in class `Component`

  - ### deinitialize

    protected void deinitialize()
    Releases the camera when the view stops being shown.
    Overrides:
      `deinitialize` in class `Component`