Class ElementAbstract

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 is an abstract class that needs to be subclassed to work. It handles style and text-font properties for the Element and any child elements, along with working with the Registry to create unique ids, but does not have any tools for formatting x or y positions or connections to a Stave.

Hierarchy

Constructors

Properties

TEXT_FONT: Required<FontInfo> = ...

Default font for text. This is not related to music engraving. Instead, see Flow.setMusicFont(...fontNames) to customize the font for musical symbols placed on the score.

Accessors

  • get font(): string
  • Returns the CSS compatible font string for the text font.

    Returns string

  • set font(f): 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 fontInfo(): Required<FontInfo>
  • Return a copy of the current FontInfo object.

    Returns Required<FontInfo>

  • set fontInfo(fontInfo): void
  • Parameters

    Returns void

  • get fontSize(): string
  • Returns string

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

  • set fontSize(size): 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 fontSizeInPixels(): number
  • Returns number

    the font size in px.

  • get fontSizeInPoints(): number
  • Returns number

    the font size in pt.

  • get fontStyle(): string
  • Returns string

    a CSS font-style string (e.g., 'italic').

  • set fontStyle(style): void
  • Parameters

    • style: string

    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): void
  • Parameters

    • weight: string | number

    Returns void

  • get CATEGORY(): string
  • Returns string

Methods

  • Adds a child Element 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 Element

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

    Parameters

    • className: string

    Returns Element

  • Draw an element.

    Parameters

    • Rest ...args: any[]

    Returns void

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

    Returns void

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

    Parameters

    • name: string

    Returns any

  • Returns string

  • Return the context, such as an SVGContext or CanvasContext object.

    Returns undefined | RenderContext

  • 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

  • Return the rendered status.

    Returns boolean

  • Call back from registry after the element is registered.

    Parameters

    Returns Element

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

    Parameters

    • className: string

    Returns Element

  • Reset the text font to the style indicated by the static TEXT_FONT property. Subclasses can call this to initialize textFont for the first time.

    Returns void

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

    Parameters

    • name: string
    • value: undefined | string

    Returns Element

  • Set the context to an SVGContext or CanvasContext object

    Parameters

    Returns Element

  • 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

    • Optional font: 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).

    • Optional size: string | number

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

    • Optional weight: string | number

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

    • Optional style: 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 Element

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

    Parameters

    • Optional size: string | number

    Returns Element

  • Set the element & associated children style used for rendering.

    Parameters

    Returns Element

  • Set the rendered status.

    Parameters

    • rendered: boolean = true

    Returns Element

  • Set the element style used to render.

    Example:

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

    Note: If the element draws additional sub-elements (ie.: 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.draw();

    or using drawWithStyle:

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

    Parameters

    Returns Element