modifier.js

VexFlow - Copyright (c) Mohit Muthanna 2010.

Description

Modifier is an abstract interface for notational elements that modify a Note. Examples of modifiers are Accidental, Annotation, Stroke, etc.

For a Modifier instance to be positioned correctly, it must be part of a ModifierContext. All modifiers in the same context are rendered relative to one another.

Typically, all modifiers to a note are part of the same ModifierContext instance. Also, in multi-voice staves, all modifiers to notes on the same tick are part of the same ModifierContext. This ensures that multiple voices don’t trample all over each other.

import { Vex } from './vex';
import { Element } from './element';

To enable logging for this class. Set Vex.Flow.Modifier.DEBUG to true. function L(…args) { if (Modifier.DEBUG) Vex.L(‘Vex.Flow.Modifier’, args); }

export class Modifier extends Element {
  static get CATEGORY() { return 'none'; }

Modifiers can be positioned almost anywhere, relative to a note.

  static get Position() {
    return {
      LEFT: 1,
      RIGHT: 2,
      ABOVE: 3,
      BELOW: 4,
    };
  }

  constructor() {
    super();
    this.attrs.type = 'Modifier';

    this.width = 0;

Modifiers are attached to a note and an index. An index is a specific head in a chord.

    this.note = null;
    this.index = null;

The text_line is reserved space above or below a stave.

    this.text_line = 0;
    this.position = Modifier.Position.LEFT;
    this.modifier_context = null;
    this.x_shift = 0;
    this.y_shift = 0;
    this.spacingFromNextModifier = 0;
  }

Every modifier has a category. The ModifierContext uses this to determine the type and order of the modifiers.

  getCategory() { return Modifier.CATEGORY; }

Get and set modifier widths.

  getWidth() { return this.width; }
  setWidth(width) { this.width = width; return this; }

Get and set attached note (StaveNote, TabNote, etc.)

  getNote() { return this.note; }
  setNote(note) { this.note = note; return this; }

Get and set note index, which is a specific note in a chord.

  getIndex() { return this.index; }
  setIndex(index) { this.index = index; return this; }

Every modifier must be part of a ModifierContext.

  getModifierContext() { return this.modifier_context; }
  setModifierContext(c) { this.modifier_context = c; return this; }

Get and set articulation position.

  getPosition() { return this.position; }
  setPosition(position) { this.position = position; return this; }

Set the text_line for the modifier.

  setTextLine(line) { this.text_line = line; return this; }

Shift modifier down y pixels. Negative values shift up.

  setYShift(y) { this.y_shift = y; return this; }

  setSpacingFromNextModifier(x) {
    this.spacingFromNextModifier = x;
  }

  getSpacingFromNextModifier() { return this.spacingFromNextModifier; }

Shift modifier x pixels in the direction of the modifier. Negative values shift reverse.

  setXShift(x) {
    this.x_shift = 0;
    if (this.position === Modifier.Position.LEFT) {
      this.x_shift -= x;
    } else {
      this.x_shift += x;
    }
  }
  getXShift() { return this.x_shift; }

Render the modifier onto the canvas.

  draw() {
    this.checkContext();
    throw new Vex.RERR('MethodNotImplemented', 'draw() not implemented for this modifier.');
  }
}

modifier.js

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Description