Trilium Frontend API
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    Interface OffscreenCanvas

    When using the element or the Canvas API, rendering, animation, and user interaction usually happen on the main execution thread of a web application. The computation relating to canvas animations and rendering can have a significant impact on application performance.

    MDN Reference

    interface OffscreenCanvas {
        height: number;
        oncontextlost: (this: OffscreenCanvas, ev: Event) => any;
        oncontextrestored: (this: OffscreenCanvas, ev: Event) => any;
        width: number;
        addEventListener<K extends keyof OffscreenCanvasEventMap>(
            type: K,
            listener: (this: OffscreenCanvas, ev: OffscreenCanvasEventMap[K]) => any,
            options?: boolean | AddEventListenerOptions,
        ): void;
        addEventListener(
            type: string,
            listener: EventListenerOrEventListenerObject,
            options?: boolean | AddEventListenerOptions,
        ): void;
        convertToBlob(options?: ImageEncodeOptions): Promise<Blob>;
        dispatchEvent(event: Event): boolean;
        getContext(
            contextId: "2d",
            options?: any,
        ): OffscreenCanvasRenderingContext2D;
        getContext(
            contextId: "bitmaprenderer",
            options?: any,
        ): ImageBitmapRenderingContext;
        getContext(contextId: "webgl", options?: any): WebGLRenderingContext;
        getContext(contextId: "webgl2", options?: any): WebGL2RenderingContext;
        getContext(
            contextId: OffscreenRenderingContextId,
            options?: any,
        ): OffscreenRenderingContext;
        removeEventListener<K extends keyof OffscreenCanvasEventMap>(
            type: K,
            listener: (this: OffscreenCanvas, ev: OffscreenCanvasEventMap[K]) => any,
            options?: boolean | EventListenerOptions,
        ): void;
        removeEventListener(
            type: string,
            listener: EventListenerOrEventListenerObject,
            options?: boolean | EventListenerOptions,
        ): void;
        transferToImageBitmap(): ImageBitmap;
    }

    Hierarchy

    • EventTarget
      • OffscreenCanvas
    Index

    Properties

    height oncontextlost oncontextrestored width

    Methods

    addEventListener convertToBlob dispatchEvent getContext removeEventListener transferToImageBitmap

    Properties

    height: number

    The height property returns and sets the height of an OffscreenCanvas object.

    MDN Reference

    oncontextlost: (this: OffscreenCanvas, ev: Event) => any

    MDN Reference

    oncontextrestored: (this: OffscreenCanvas, ev: Event) => any

    MDN Reference

    width: number

    The width property returns and sets the width of an OffscreenCanvas object.

    MDN Reference

    Methods

    • The OffscreenCanvas.convertToBlob() method creates a Blob object representing the image contained in the canvas.

      MDN Reference

      Parameters

      Returns Promise<Blob>

    • The dispatchEvent() method of the EventTarget sends an Event to the object, (synchronously) invoking the affected event listeners in the appropriate order. The normal event processing rules (including the capturing and optional bubbling phase) also apply to events dispatched manually with dispatchEvent().

      MDN Reference

      Parameters

      • event: Event

      Returns boolean

    • The removeEventListener() method of the EventTarget interface removes an event listener previously registered with EventTarget.addEventListener() from the target. The event listener to be removed is identified using a combination of the event type, the event listener function itself, and various optional options that may affect the matching process; see Matching event listeners for removal.

      MDN Reference

      Type Parameters

      Parameters

      Returns void

    • The removeEventListener() method of the EventTarget interface removes an event listener previously registered with EventTarget.addEventListener() from the target. The event listener to be removed is identified using a combination of the event type, the event listener function itself, and various optional options that may affect the matching process; see Matching event listeners for removal.

      MDN Reference

      Parameters

      Returns void

    • The OffscreenCanvas.transferToImageBitmap() method creates an ImageBitmap object from the most recently rendered image of the OffscreenCanvas. The OffscreenCanvas allocates a new image for its subsequent rendering.

      MDN Reference

      Returns ImageBitmap

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