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    Class Element

    Element implements a generic base class for VexFlow, with implementations of general functions and properties that can be inherited by all VexFlow elements.

    The Element handles style and font properties for the Element and any child elements, along with working with the Registry to create unique ids.

    The text is a series of unicode characters (including SMuFL codes). The textFont property contains information required to style the text (i.e., font family, size, weight, and style). This font family is a comma separated list of fonts. The method measureText calculates the textMetrics, boundingBox, height and width of the text. The method renderText(...) will render the text using the provided context and coordinates, taking xShift and yShift into account.

    Hierarchy (View Summary)

    Index

    Constructors

    Properties

    _fontInfo: Required<FontInfo>
    _height: number = 0
    _text: string = ''
    _textMetrics: TextMetrics = ...
    _width: number = 0
    children: Element[] = []
    fontScale: number
    metricsValid: boolean = false
    parent?: Element
    registry?: Registry
    rendered: boolean
    shouldDrawPointerRect: boolean
    style: ElementStyle = {}
    x: number = 0
    xShift: number = 0
    y: number = 0
    yShift: number = 0
    ID: number = 1000

    Accessors

    • get font(): string

      Returns the CSS compatible font string for the text font.

      Returns string

    • set font(f: string): void

      Provide a CSS compatible font string (e.g., 'bold 16px Arial') that will be applied to text (not glyphs).

      Parameters

      • f: string

      Returns void

    • get fontSize(): string

      Returns string

      a CSS font-size string (e.g., '18pt', '12px', '1em').

    • set fontSize(size: string | number): void

      The size is 1) a string of the form '10pt' or '16px', compatible with the CSS font-size property. or 2) a number, which is interpreted as a point size (i.e. 12 == '12pt').

      Parameters

      • size: string | number

      Returns void

    • get fontWeight(): string

      Returns string

      a CSS font-weight string (e.g., 'bold'). As in CSS, font-weight is always returned as a string, even if it was set as a number.

    • set fontWeight(weight: string | number): void

      Set the font weight.

      Parameters

      • weight: string | number

      Returns void

    Methods

    • Adds a child to the Element, which lets it inherit the same style as the parent when setGroupStyle() is called.

      Examples of children are noteheads and stems. Modifiers such as Accidentals are generally not set as children.

      Note that StaveNote calls setGroupStyle() when setStyle() is called.

      Parameters

      Returns this

    • Add a class label (An element can have multiple class labels).

      Parameters

      • className: string

      Returns this

    • Draw pointer rect. This allows mouse interaction with the element

      Returns void

    • Draw the element and all its sub-elements (i.e.: Modifiers in a Stave) with the element's style (see getStyle() and setStyle())

      Returns this

    • Return an attribute, such as 'id', 'type' or 'class'.

      Parameters

      • name: string

      Returns any

    • Get the css string describing this Element's text font. e.g., 'bold 10pt Arial'.

      Returns string

    • Returns string

      a CSS font-size string (e.g., '18pt', '12px', '1em'). See Element.fontSizeInPixels or Element.fontSizeInPoints if you need to get a number for calculation purposes.

    • Return associated SVGElement.

      Parameters

      • suffix: string = ''

      Returns undefined | SVGElement

    • Check if it has a class label (An element can have multiple class labels).

      Parameters

      • className: string

      Returns boolean

    • Remove a class label (An element can have multiple class labels).

      Parameters

      • className: string

      Returns this

    • Set an attribute such as 'id', 'class', or 'type'.

      Parameters

      • name: string
      • value: undefined | string

      Returns this

    • Set the element's text font family, size, weight, style (e.g., Arial, 10pt, bold, italic).

      This attribute does not determine the font used for musical Glyphs like treble clefs.

      Parameters

      • Optionalfont: string | FontInfo

        is 1) a FontInfo object or 2) a string formatted as CSS font shorthand (e.g., 'bold 10pt Arial') or 3) a string representing the font family (at least one of size, weight, or style must also be provided).

      • Optionalsize: string | number

        a string specifying the font size and unit (e.g., '16pt'), or a number (the unit is assumed to be 'pt').

      • Optionalweight: string | number

        is a string (e.g., 'bold', 'normal') or a number (100, 200, ... 900).

      • Optionalstyle: string

        is a string (e.g., 'italic', 'normal'). If no arguments are provided, then the font is set to the default font. Each Element subclass may specify its own default by overriding the static TEXT_FONT property.

      Returns this

    • Change the font size, while keeping everything else the same.

      Parameters

      • Optionalsize: string | number

      Returns this

    • Set the rendered status.

      Parameters

      • rendered: boolean = true

      Returns this

    • Set the element style used to render.

      Example:

      element.setStyle({ fillStyle: 'red', strokeStyle: 'red' });
      element.drawWithStyle();

      Note: If the element draws additional sub-elements (i.e.: Modifiers in a Stave), the style can be applied to all of them by means of the context:

      element.setStyle({ fillStyle: 'red', strokeStyle: 'red' });
      element.getContext().setFillStyle('red');
      element.getContext().setStrokeStyle('red');
      element.drawWithStyle();

      or using drawWithStyle:

      element.setStyle({ fillStyle: 'red', strokeStyle: 'red' });
      element.drawWithStyle();

      Parameters

      Returns this

    • Set shift element right xShift pixels. Negative values shift left.

      Parameters

      • xShift: number

      Returns this

    • Shift element down yShift pixels. Negative values shift up.

      Parameters

      • yShift: number

      Returns this

    • Returns undefined | HTMLCanvasElement | OffscreenCanvas

    • Measure the text using the FontInfo related with key.

      Parameters

      • text: string
      • key: string = ''

      Returns number

    • Parameters

      • canvas: HTMLCanvasElement | OffscreenCanvas

      Returns void