/**
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* @module
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* Core Camera interfaces.
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*
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* @author mebjas <minhazav@gmail.com>
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*/
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/** Camera device interface. */
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export interface CameraDevice {
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id: string;
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label: string;
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}
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//#region Features
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/** Generic capability of camera. */
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export interface CameraCapability<T> {
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/** Returns {@code true} if the capability is supported by the camera. */
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isSupported(): boolean;
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/** Apply the {@code value} to camera for this capability. */
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apply(value: T): Promise<void>;
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/** Returns current value of this capability. */
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value(): T | null;
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}
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/** Capability of the camera that has range. */
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export interface RangeCameraCapability extends CameraCapability<number> {
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/** Min value allowed for this capability. */
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min(): number;
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/** Max value allowed for this capability. */
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max(): number;
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/** Steps allowed for this capability. */
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step(): number;
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}
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/** Capability of camera that is boolean in nature. */
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export interface BooleanCameraCapability extends CameraCapability<boolean> {}
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/** Class exposing different capabilities of camera. */
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export interface CameraCapabilities {
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/** Zoom capability of the camera. */
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zoomFeature(): RangeCameraCapability;
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/** Torch capability of the camera. */
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torchFeature(): BooleanCameraCapability;
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}
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//#endregion
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/** Type for callback called when camera surface is ready. */
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export type OnRenderSurfaceReady
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= (viewfinderWidth: number, viewfinderHeight: number) => void;
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/** Callbacks around camera rendering. */
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export interface RenderingCallbacks {
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onRenderSurfaceReady: OnRenderSurfaceReady;
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}
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/**
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* Interface for a rendered camera that is actively showing feed on a surface.
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*/
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export interface RenderedCamera {
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/**
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* Returns the video surface.
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*
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* @throws error if method is called when scanner is not in scanning state.
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*/
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getSurface(): HTMLVideoElement;
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/**
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* Pauses the camera feed.
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*
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* @throws error if method is called when scanner is not in scanning state.
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*/
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pause(): void;
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/**
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* Resumes the camera feed, if it's in paused state.
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*
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* @param onResumeCallback callback that is called when camera resumes.
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*
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* @throws error if {@link RenderedCamera} instance is already closed.
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*/
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resume(onResumeCallback: () => void): void;
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/**
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* Returns {@code true} if the instance is paused.
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*
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* @throws error if {@link RenderedCamera} instance is already closed.
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*/
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isPaused(): boolean;
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/**
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* Closes the instance.
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*
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* <p> The instance cannot be used after closing.
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*/
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close(): Promise<void>;
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// ---------------------------------------------------------------------------
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// Direct Camera Access APIs.
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//
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// The APIs below are in flavour similar to what Javascript exposes.
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// ---------------------------------------------------------------------------
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/**
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* Returns the capabilities of the running camera stream.
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*
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* Read more: https://developer.mozilla.org/en-US/docs/Web/API/MediaStreamTrack/getConstraints
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*
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* @returns the capabilities of a running video track.
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* @throws error if {@link RenderedCamera} instance is already closed.
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*/
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getRunningTrackCapabilities(): MediaTrackCapabilities;
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/**
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* Returns the object containing the current values of each constrainable
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* property of the running video track.
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*
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* Read more: https://developer.mozilla.org/en-US/docs/Web/API/MediaStreamTrack/getSettings
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*
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* @returns the supported settings of the running video track.
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* @throws error if {@link RenderedCamera} instance is already closed.
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*/
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getRunningTrackSettings(): MediaTrackSettings;
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/**
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* Apply a video constraints on running video track from camera.
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*
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* Important: Changing aspectRatio while scanner is running is not supported
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* with this API.
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*
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* @param {MediaTrackConstraints} specifies a variety of video or camera
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* controls as defined in
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* https://developer.mozilla.org/en-US/docs/Web/API/MediaTrackConstraints
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* @returns a Promise which succeeds if the passed constraints are applied,
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* fails otherwise.
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* @throws error if {@link RenderedCamera} instance is already closed.
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*/
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applyVideoConstraints(constraints: MediaTrackConstraints): Promise<void>;
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/**
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* Returns all capabilities of the camera.
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*/
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getCapabilities(): CameraCapabilities;
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}
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/** Options for rendering camera feed. */
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export interface CameraRenderingOptions {
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/**
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* Aspect ratio to setup the surface with.
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*
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* <p> Setting this value doesn't guarantee the exact value to be applied.
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*/
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aspectRatio?: number;
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}
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/** Interface for the camera. */
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export interface Camera {
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/**
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* Renders camera to {@link HTMLVideoElement} as a child of
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* {@code parentElement}.
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*
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* @params parentElement Parent HtmlElement to render camera feed into
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* @params options rendering options
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* @params callbacks callbacks associated with rendering
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*
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* @returns the {@link RenderedCamera} instance.
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*/
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render(
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parentElement: HTMLElement,
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options: CameraRenderingOptions,
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callbacks: RenderingCallbacks)
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: Promise<RenderedCamera>;
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}
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