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Class Beam

Beams span over a set of StemmableNotes.

Hierarchy

Index

Constructors

constructor

Properties

notes

notes: StemmableNote[]

postFormatted

postFormatted: boolean

render_options

render_options: { beam_width: number; flat_beam_offset?: number; flat_beams: boolean; max_slope: number; min_flat_beam_offset: number; min_slope: number; partial_beam_length: number; secondary_break_ticks?: number; show_stemlets: boolean; slope_cost: number; slope_iterations: number; stemlet_extension: number }

Type declaration

  • beam_width: number
  • Optional flat_beam_offset?: number
  • flat_beams: boolean
  • max_slope: number
  • min_flat_beam_offset: number
  • min_slope: number
  • partial_beam_length: number
  • Optional secondary_break_ticks?: number
  • show_stemlets: boolean
  • slope_cost: number
  • slope_iterations: number
  • stemlet_extension: number

slope

slope: number = 0

Static TEXT_FONT

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

font

  • get font(): string
  • set font(f: string): void
  • Returns the CSS compatible font string.

    Returns string

  • Provide a CSS compatible font string (e.g., 'bold 16px Arial').

    Parameters

    • f: string

    Returns void

fontInfo

  • Return a copy of the current FontInfo object.

    Returns Required<FontInfo>

  • Return a copy of the current FontInfo object.

    Parameters

    Returns void

fontSize

  • get fontSize(): string
  • 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').

    Returns string

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

  • 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

fontSizeInPixels

  • get fontSizeInPixels(): number
  • Returns number

    the font size in px.

fontSizeInPoints

  • get fontSizeInPoints(): number
  • Returns number

    the font size in pt.

fontStyle

  • get fontStyle(): string
  • set fontStyle(style: string): void
  • Returns string

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

  • Parameters

    • style: string

    Returns void

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

fontWeight

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

  • Parameters

    • weight: string | number

    Returns void

    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.

Static CATEGORY

  • get CATEGORY(): string
  • Returns string

Methods

addChildElement

addClass

  • addClass(className: string): Beam
  • Add a class label (An element can have multiple class labels).

    Parameters

    • className: string

    Returns Beam

applyStemExtensions

  • applyStemExtensions(): void
  • Create new stems for the notes in the beam, so that each stem extends into the beams.

    Returns void

applyStyle

breakSecondaryAt

  • breakSecondaryAt(indices: number[]): Beam
  • Set which note indices to break the secondary beam at.

    Parameters

    • indices: number[]

    Returns Beam

calculateFlatSlope

  • calculateFlatSlope(): void
  • Calculate a slope and y-shift for flat beams.

    Returns void

calculateSlope

  • calculateSlope(): void
  • Calculate the best possible slope for the provided notes.

    Returns void

checkContext

draw

  • draw(): void
  • Render the beam to the canvas context

    Returns void

drawWithStyle

  • drawWithStyle(): void
  • Draw the element and all its sub-elements (ie.: Modifiers in a Stave) with the element style.

    Returns void

getAttribute

  • getAttribute(name: string): any

getAttributes

getBeamCount

  • getBeamCount(): number
  • Get the max number of beams in the set of notes.

    Returns number

getBeamLines

  • getBeamLines(duration: string): { end?: number; start: number }[]
  • Get the x coordinates for the beam lines of specific duration.

    Parameters

    • duration: string

    Returns { end?: number; start: number }[]

getBeamYToDraw

  • getBeamYToDraw(): number
  • Return the Beam y offset.

    Returns number

getBoundingBox

getCategory

  • getCategory(): string

getContext

getFont

  • getFont(): string

getFontSize

  • getFontSize(): 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.

getNotes

getSVGElement

  • getSVGElement(suffix?: string): undefined | SVGElement
  • Return associated SVGElement.

    Parameters

    • suffix: string = ''

    Returns undefined | SVGElement

getSlopeY

  • getSlopeY(x: number, first_x_px: number, first_y_px: number, slope: number): number
  • Return the y coordinate for linear function.

    Parameters

    • x: number
    • first_x_px: number
    • first_y_px: number
    • slope: number

    Returns number

getStemDirection

  • getStemDirection(): number
  • Get the direction of the beam

    Returns number

getStyle

hasClass

  • hasClass(className: string): boolean
  • Check if it has a class label (An element can have multiple class labels).

    Parameters

    • className: string

    Returns boolean

isRendered

  • isRendered(): boolean

lookupBeamDirection

  • lookupBeamDirection(duration: string, prev_tick: number, tick: number, next_tick: number, noteIndex: number): PartialBeamDirection
  • Return upper level beam direction.

    Parameters

    • duration: string
    • prev_tick: number
    • tick: number
    • next_tick: number
    • noteIndex: number

    Returns PartialBeamDirection

onRegister

postFormat

  • postFormat(): void
  • Post-format the beam. This can only be called after the notes in the beam have both x and y values. ie: they've been formatted and have staves.

    Returns void

preFormat

  • Pre-format the beam.

    Returns Beam

removeClass

  • removeClass(className: string): Beam
  • Remove a class label (An element can have multiple class labels).

    Parameters

    • className: string

    Returns Beam

resetFont

  • resetFont(): void
  • 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

restoreStyle

setAttribute

  • setAttribute(name: string, value: any): Beam

setContext

setFont

  • setFont(font?: string | FontInfo, size?: string | number, weight?: string | number, style?: string): Beam
  • Set the element's font family, size, weight, style (e.g., Arial, 10pt, bold, italic).

    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 Beam

setFontSize

  • setFontSize(size?: string | number): Beam
  • Change the font size, while keeping everything else the same.

    Parameters

    • Optional size: string | number

    Returns Beam

setGroupStyle

setPartialBeamSideAt

  • Forces the direction of a partial beam (a secondary-level beam that exists on one note only of the beam group). This is useful in rhythms such as 6/8 eighth-sixteenth-eighth-sixteenth, where the direction of the beam on the first sixteenth note can help imply whether the rhythm is to be felt as three groups of eighth notes (typical) or as two groups of three-sixteenths (less common):

     ┌───┬──┬──┐      ┌──┬──┬──┐
    │ ├─ │ ─┤ vs │ ─┤ │ ─┤
    │ │ │ │ │ │ │ │

    Parameters

    Returns Beam

setRendered

  • setRendered(rendered?: boolean): Beam

setStyle

  • 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 Beam

unsetPartialBeamSideAt

  • unsetPartialBeamSideAt(noteIndex: number): Beam
  • Restore the default direction of a partial beam (a secondary-level beam that does not connect to any other notes).

    Parameters

    • noteIndex: number

    Returns Beam

Static applyAndGetBeams

  • A helper function to automatically build basic beams for a voice. For more complex auto-beaming use Beam.generateBeams().

    Parameters

    • voice: Voice

      the voice to generate the beams for

    • Optional stem_direction: number

      a stem direction to apply to the entire voice

    • Optional groups: Fraction[]

      an array of Fraction representing beat groupings for the beam

    Returns Beam[]

Static generateBeams

  • generateBeams(notes: StemmableNote[], config?: { beam_middle_only?: boolean; beam_rests?: boolean; flat_beam_offset?: number; flat_beams?: boolean; groups?: Fraction[]; maintain_stem_directions?: boolean; secondary_breaks?: string; show_stemlets?: boolean; stem_direction?: number }): Beam[]
  • A helper function to autimatically build beams for a voice with configuration options.

    Example configuration object:

    config = {
    groups: [new Vex.Flow.Fraction(2, 8)],
    stem_direction: -1,
    beam_rests: true,
    beam_middle_only: true,
    show_stemlets: false
    };

    Parameters

    • notes: StemmableNote[]

      an array of notes to create the beams for

    • config: { beam_middle_only?: boolean; beam_rests?: boolean; flat_beam_offset?: number; flat_beams?: boolean; groups?: Fraction[]; maintain_stem_directions?: boolean; secondary_breaks?: string; show_stemlets?: boolean; stem_direction?: number } = {}

      the configuration object

      • Optional beam_middle_only?: boolean

        set to true to only beam rests in the middle of the beat

      • Optional beam_rests?: boolean

        set to true to include rests in the beams

      • Optional flat_beam_offset?: number
      • Optional flat_beams?: boolean
      • Optional groups?: Fraction[]

        array of Fractions that represent the beat structure to beam the notes

      • Optional maintain_stem_directions?: boolean

        set to true to not apply new stem directions

      • Optional secondary_breaks?: string
      • Optional show_stemlets?: boolean

        set to true to draw stemlets for rests

      • Optional stem_direction?: number

        set to apply the same direction to all notes

    Returns Beam[]

Static getDefaultBeamGroups

  • getDefaultBeamGroups(time_sig: string): Fraction[]
  • Get the default beam groups for a provided time signature. Attempt to guess if the time signature is not found in table. Currently this is fairly naive.

    Parameters

    • time_sig: string

    Returns Fraction[]