satie/src/implChord_stemView.ts

A sheet music renderer for the web

/**
 * This file is part of Satie music engraver <https://github.com/jnetterf/satie>.
 * Copyright (C) Joshua Netterfield <joshua.ca> 2015 - present.
 * 
 * Satie is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 * 
 * Satie is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 * 
 * You should have received a copy of the GNU Affero General Public License
 * along with Satie.  If not, see <http://www.gnu.org/licenses/>.
 */

import {Stem, StemType, Tremolo} from "musicxml-interfaces";
import {createFactory, Component, DOM, PropTypes} from "react";
import * as invariant from "invariant";

import Line from "./private_views_line";
import Glyph from "./private_views_glyph";
import {getFontOffset} from "./private_smufl";

const $Line = createFactory(Line);
const $Glyph = createFactory(Glyph);

export interface IProps {
    key?: string | number;
    spec: Stem;
    notehead: string;
    bestHeight: number;
    width: number;
    tremolo: Tremolo;
}

/**
 * Renders a stem based on a height decided in Note.
 */
export default class StemView extends Component<IProps, void> {
    static contextTypes = {
        originY: PropTypes.number.isRequired
    } as any;

    context: {
        originY: number;
    };

    render(): any {
        const {spec, notehead, tremolo, width} = this.props;
        const {defaultX, relativeX, defaultY, relativeY, color} = spec;
        if (spec.type === StemType.Double) {
            return null;
        }
        const direction = spec.type === StemType.Up ? 1 : -1; // TODO: StemType.Double
        const lineXOffset = direction * - width / 2;
        const offset = getFontOffset(notehead, direction) || [0];
        const x = defaultX + (relativeX || (offset[0] * 10 + lineXOffset));
        invariant(isFinite(x), "Invalid x offset %s", x);

        const dY = this.props.bestHeight * direction;

        let elements: any[] = [];
        elements.push($Line({
            key: "s",
            stroke: color,
            strokeWidth: width,
            x1: x,
            x2: x,
            y1: this.context.originY - defaultY - (relativeY || 0) - offset[1] * 10,
            y2: this.context.originY - defaultY - (relativeY || 0) - offset[1] * 10 - dY
        }));

        if (tremolo) {
            elements.push($Glyph({
                key: "t",
                glyphName: `tremolo${tremolo.data || "1"}`,
                x: x,
                fill: "black",
                y: this.context.originY - defaultY - (relativeY || 0) - dY * 4 / 5
            }));
        }

        if (elements.length === 1) {
            return elements[0];
        } else {
            return DOM.g(null, elements);
        }
    }
}