//@ts-check
const MathHelper = require('./MathHelper')
const Vector2 = require('./Vector2')
const Line = require('./Line')
const Vertex = require('./Vertex')
const Ring = require('./Ring')
const { getChargeText } = require('./UtilityFunctions')
/**
* A class wrapping a canvas element.
*
* @property {HTMLElement} canvas The HTML element for the canvas associated with this CanvasWrapper instance.
* @property {CanvasRenderingContext2D} ctx The CanvasRenderingContext2D of the canvas associated with this CanvasWrapper instance.
* @property {Object} colors The colors object as defined in the SmilesDrawer options.
* @property {Object} opts The SmilesDrawer options.
* @property {Number} drawingWidth The width of the canvas.
* @property {Number} drawingHeight The height of the canvas.
* @property {Number} offsetX The horizontal offset required for centering the drawing.
* @property {Number} offsetY The vertical offset required for centering the drawing.
* @property {Number} fontLarge The large font size in pt.
* @property {Number} fontSmall The small font size in pt.
*/
class CanvasWrapper {
/**
* The constructor for the class CanvasWrapper.
*
* @param {(String|HTMLElement)} target The canvas id or the canvas HTMLElement.
* @param {ThemeManager} themeManager Theme manager for setting proper colors.
* @param {Object} options The smiles drawer options object.
*/
constructor(target, themeManager, options) {
if (typeof target === 'string' || target instanceof String) {
this.canvas = document.getElementById(target);
} else {
this.canvas = target;
}
this.ctx = this.canvas.getContext('2d');
this.themeManager = themeManager;
this.opts = options;
this.drawingWidth = 0.0;
this.drawingHeight = 0.0;
this.offsetX = 0.0;
this.offsetY = 0.0;
this.fontLarge = this.opts.fontSizeLarge + 'pt Helvetica, Arial, sans-serif';
this.fontSmall = this.opts.fontSizeSmall + 'pt Helvetica, Arial, sans-serif';
this.updateSize(this.opts.width, this.opts.height);
this.ctx.font = this.fontLarge;
this.hydrogenWidth = this.ctx.measureText('H').width;
this.halfHydrogenWidth = this.hydrogenWidth / 2.0;
this.halfBondThickness = this.opts.bondThickness / 2.0;
// TODO: Find out why clear was here.
// this.clear();
}
/**
* Update the width and height of the canvas
*
* @param {Number} width
* @param {Number} height
*/
updateSize(width, height) {
this.devicePixelRatio = window.devicePixelRatio || 1;
this.backingStoreRatio = this.ctx.webkitBackingStorePixelRatio || this.ctx.mozBackingStorePixelRatio ||
this.ctx.msBackingStorePixelRatio || this.ctx.oBackingStorePixelRatio ||
this.ctx.backingStorePixelRatio || 1;
this.ratio = this.devicePixelRatio / this.backingStoreRatio;
if (this.ratio !== 1) {
this.canvas.width = width * this.ratio;
this.canvas.height = height * this.ratio;
this.canvas.style.width = width + 'px';
this.canvas.style.height = height + 'px';
this.ctx.setTransform(this.ratio, 0, 0, this.ratio, 0, 0);
} else {
this.canvas.width = width * this.ratio;
this.canvas.height = height * this.ratio;
}
}
/**
* Sets a provided theme.
*
* @param {Object} theme A theme from the smiles drawer options.
*/
setTheme(theme) {
this.colors = theme;
}
/**
* Scale the canvas based on vertex positions.
*
* @param {Vertex[]} vertices An array of vertices containing the vertices associated with the current molecule.
*/
scale(vertices) {
// Figure out the final size of the image
let maxX = -Number.MAX_VALUE;
let maxY = -Number.MAX_VALUE;
let minX = Number.MAX_VALUE;
let minY = Number.MAX_VALUE;
for (var i = 0; i < vertices.length; i++) {
if (!vertices[i].value.isDrawn) {
continue;
}
let p = vertices[i].position;
if (maxX < p.x) maxX = p.x;
if (maxY < p.y) maxY = p.y;
if (minX > p.x) minX = p.x;
if (minY > p.y) minY = p.y;
}
// Add padding
var padding = this.opts.padding;
maxX += padding;
maxY += padding;
minX -= padding;
minY -= padding;
this.drawingWidth = maxX - minX;
this.drawingHeight = maxY - minY;
var scaleX = this.canvas.offsetWidth / this.drawingWidth;
var scaleY = this.canvas.offsetHeight / this.drawingHeight;
var scale = (scaleX < scaleY) ? scaleX : scaleY;
this.ctx.scale(scale, scale);
this.offsetX = -minX;
this.offsetY = -minY;
// Center
if (scaleX < scaleY) {
this.offsetY += this.canvas.offsetHeight / (2.0 * scale) - this.drawingHeight / 2.0;
} else {
this.offsetX += this.canvas.offsetWidth / (2.0 * scale) - this.drawingWidth / 2.0;
}
}
/**
* Resets the transform of the canvas.
*/
reset() {
this.ctx.setTransform(1, 0, 0, 1, 0, 0);
}
/**
* Returns the hex code of a color associated with a key from the current theme.
*
* @param {String} key The color key in the theme (e.g. C, N, BACKGROUND, ...).
* @returns {String} A color hex value.
*/
getColor(key) {
key = key.toUpperCase();
if (key in this.colors) {
return this.colors[key];
}
return this.colors['C'];
}
/**
* Draws a circle to a canvas context.
* @param {Number} x The x coordinate of the circles center.
* @param {Number} y The y coordinate of the circles center.
* @param {Number} radius The radius of the circle
* @param {String} color A hex encoded color.
* @param {Boolean} [fill=true] Whether to fill or stroke the circle.
* @param {Boolean} [debug=false] Draw in debug mode.
* @param {String} [debugText=''] A debug message.
*/
drawCircle(x, y, radius, color, fill = true, debug = false, debugText = '') {
let ctx = this.ctx;
let offsetX = this.offsetX;
let offsetY = this.offsetY;
ctx.save();
ctx.lineWidth = 1.5;
ctx.beginPath();
ctx.arc(x + offsetX, y + offsetY, radius, 0, MathHelper.twoPI, true);
ctx.closePath();
if (debug) {
if (fill) {
ctx.fillStyle = '#f00';
ctx.fill();
} else {
ctx.strokeStyle = '#f00';
ctx.stroke();
}
this.drawDebugText(x, y, debugText);
} else {
if (fill) {
ctx.fillStyle = color;
ctx.fill();
} else {
ctx.strokeStyle = color;
ctx.stroke();
}
}
ctx.restore();
}
/**
* Draw a line to a canvas.
*
* @param {Line} line A line.
* @param {Boolean} [dashed=false] Whether or not the line is dashed.
* @param {Number} [alpha=1.0] The alpha value of the color.
*/
drawLine(line, dashed = false, alpha = 1.0) {
let ctx = this.ctx;
let offsetX = this.offsetX;
let offsetY = this.offsetY;
// Add a shadow behind the line
let shortLine = line.clone().shorten(4.0);
let l = shortLine.getLeftVector().clone();
let r = shortLine.getRightVector().clone();
l.x += offsetX;
l.y += offsetY;
r.x += offsetX;
r.y += offsetY;
// Draw the "shadow"
if (!dashed) {
ctx.save();
ctx.globalCompositeOperation = 'destination-out';
ctx.beginPath();
ctx.moveTo(l.x, l.y);
ctx.lineTo(r.x, r.y);
ctx.lineCap = 'round';
ctx.lineWidth = this.opts.bondThickness + 1.2;
ctx.strokeStyle = this.themeManager.getColor('BACKGROUND');
ctx.stroke();
ctx.globalCompositeOperation = 'source-over';
ctx.restore();
}
l = line.getLeftVector().clone();
r = line.getRightVector().clone();
l.x += offsetX;
l.y += offsetY;
r.x += offsetX;
r.y += offsetY;
ctx.save();
ctx.beginPath();
ctx.moveTo(l.x, l.y);
ctx.lineTo(r.x, r.y);
ctx.lineCap = 'round';
ctx.lineWidth = this.opts.bondThickness;
let gradient = this.ctx.createLinearGradient(l.x, l.y, r.x, r.y);
gradient.addColorStop(0.4, this.themeManager.getColor(line.getLeftElement()) ||
this.themeManager.getColor('C'));
gradient.addColorStop(0.6, this.themeManager.getColor(line.getRightElement()) ||
this.themeManager.getColor('C'));
if (dashed) {
ctx.setLineDash([1, 1.5]);
ctx.lineWidth = this.opts.bondThickness / 1.5;
}
if (alpha < 1.0) {
ctx.globalAlpha = alpha;
}
ctx.strokeStyle = gradient;
ctx.stroke();
ctx.restore();
}
/**
* Draw a wedge on the canvas.
*
* @param {Line} line A line.
* @param {Number} width The wedge width.
*/
drawWedge(line, width = 1.0) {
if (isNaN(line.from.x) || isNaN(line.from.y) ||
isNaN(line.to.x) || isNaN(line.to.y)) {
return;
}
let ctx = this.ctx;
let offsetX = this.offsetX;
let offsetY = this.offsetY;
// Add a shadow behind the line
let shortLine = line.clone().shorten(5.0);
let l = shortLine.getLeftVector().clone();
let r = shortLine.getRightVector().clone();
l.x += offsetX;
l.y += offsetY;
r.x += offsetX;
r.y += offsetY;
l = line.getLeftVector().clone();
r = line.getRightVector().clone();
l.x += offsetX;
l.y += offsetY;
r.x += offsetX;
r.y += offsetY;
ctx.save();
let normals = Vector2.normals(l, r);
normals[0].normalize();
normals[1].normalize();
let isRightChiralCenter = line.getRightChiral();
let start = l;
let end = r;
if (isRightChiralCenter) {
start = r;
end = l;
}
let t = Vector2.add(start, Vector2.multiplyScalar(normals[0], this.halfBondThickness));
let u = Vector2.add(end, Vector2.multiplyScalar(normals[0], 1.5 + this.halfBondThickness));
let v = Vector2.add(end, Vector2.multiplyScalar(normals[1], 1.5 + this.halfBondThickness));
let w = Vector2.add(start, Vector2.multiplyScalar(normals[1], this.halfBondThickness));
ctx.beginPath();
ctx.moveTo(t.x, t.y);
ctx.lineTo(u.x, u.y);
ctx.lineTo(v.x, v.y);
ctx.lineTo(w.x, w.y);
let gradient = this.ctx.createRadialGradient(r.x, r.y, this.opts.bondLength, r.x, r.y, 0);
gradient.addColorStop(0.4, this.themeManager.getColor(line.getLeftElement()) ||
this.themeManager.getColor('C'));
gradient.addColorStop(0.6, this.themeManager.getColor(line.getRightElement()) ||
this.themeManager.getColor('C'));
ctx.fillStyle = gradient;
ctx.fill();
ctx.restore();
}
/**
* Draw a dashed wedge on the canvas.
*
* @param {Line} line A line.
*/
drawDashedWedge(line) {
if (isNaN(line.from.x) || isNaN(line.from.y) ||
isNaN(line.to.x) || isNaN(line.to.y)) {
return;
}
let ctx = this.ctx;
let offsetX = this.offsetX;
let offsetY = this.offsetY;
let l = line.getLeftVector().clone();
let r = line.getRightVector().clone();
l.x += offsetX;
l.y += offsetY;
r.x += offsetX;
r.y += offsetY;
ctx.save();
let normals = Vector2.normals(l, r);
normals[0].normalize();
normals[1].normalize();
let isRightChiralCenter = line.getRightChiral();
let start;
let end;
let sStart;
let sEnd;
let shortLine = line.clone();
if (isRightChiralCenter) {
start = r;
end = l;
shortLine.shortenRight(1.0);
sStart = shortLine.getRightVector().clone();
sEnd = shortLine.getLeftVector().clone();
} else {
start = l;
end = r;
shortLine.shortenLeft(1.0);
sStart = shortLine.getLeftVector().clone();
sEnd = shortLine.getRightVector().clone();
}
sStart.x += offsetX;
sStart.y += offsetY;
sEnd.x += offsetX;
sEnd.y += offsetY;
let dir = Vector2.subtract(end, start).normalize();
ctx.strokeStyle = this.themeManager.getColor('C');
ctx.lineCap = 'round';
ctx.lineWidth = this.opts.bondThickness;
ctx.beginPath();
let length = line.getLength();
let step = 1.25 / (length / (this.opts.bondThickness * 3.0));
let changed = false;
for (var t = 0.0; t < 1.0; t += step) {
let to = Vector2.multiplyScalar(dir, t * length);
let startDash = Vector2.add(start, to);
let width = 1.5 * t;
let dashOffset = Vector2.multiplyScalar(normals[0], width);
if (!changed && t > 0.5) {
ctx.stroke();
ctx.beginPath();
ctx.strokeStyle = this.themeManager.getColor(line.getRightElement()) || this.themeManager.getColor('C');
changed = true;
}
startDash.subtract(dashOffset);
ctx.moveTo(startDash.x, startDash.y);
startDash.add(Vector2.multiplyScalar(dashOffset, 2.0));
ctx.lineTo(startDash.x, startDash.y);
}
ctx.stroke();
ctx.restore();
}
/**
* Draws a debug text message at a given position
*
* @param {Number} x The x coordinate.
* @param {Number} y The y coordinate.
* @param {String} text The debug text.
*/
drawDebugText(x, y, text) {
let ctx = this.ctx;
ctx.save();
ctx.font = '5px Droid Sans, sans-serif';
ctx.textAlign = 'start';
ctx.textBaseline = 'top';
ctx.fillStyle = '#ff0000';
ctx.fillText(text, x + this.offsetX, y + this.offsetY);
ctx.restore();
}
/**
* Draw a ball to the canvas.
*
* @param {Number} x The x position of the text.
* @param {Number} y The y position of the text.
* @param {String} elementName The name of the element (single-letter).
*/
drawBall(x, y, elementName) {
let ctx = this.ctx;
ctx.save();
ctx.beginPath();
ctx.arc(x + this.offsetX, y + this.offsetY, this.opts.bondLength / 4.5, 0, MathHelper.twoPI, false);
ctx.fillStyle = this.themeManager.getColor(elementName);
ctx.fill();
ctx.restore();
}
/**
* Draw a point to the canvas.
*
* @param {Number} x The x position of the point.
* @param {Number} y The y position of the point.
* @param {String} elementName The name of the element (single-letter).
*/
drawPoint(x, y, elementName) {
let ctx = this.ctx;
let offsetX = this.offsetX;
let offsetY = this.offsetY;
ctx.save();
ctx.globalCompositeOperation = 'destination-out';
ctx.beginPath();
ctx.arc(x + offsetX, y + offsetY, 1.5, 0, MathHelper.twoPI, true);
ctx.closePath();
ctx.fill();
ctx.globalCompositeOperation = 'source-over';
ctx.beginPath();
ctx.arc(x + this.offsetX, y + this.offsetY, 0.75, 0, MathHelper.twoPI, false);
ctx.fillStyle = this.themeManager.getColor(elementName);
ctx.fill();
ctx.restore();
}
/**
* Draw a text to the canvas.
*
* @param {Number} x The x position of the text.
* @param {Number} y The y position of the text.
* @param {String} elementName The name of the element (single-letter).
* @param {Number} hydrogens The number of hydrogen atoms.
* @param {String} direction The direction of the text in relation to the associated vertex.
* @param {Boolean} isTerminal A boolean indicating whether or not the vertex is terminal.
* @param {Number} charge The charge of the atom.
* @param {Number} isotope The isotope number.
* @param {Number} vertexCount The number of vertices in the molecular graph.
* @param {Object} attachedPseudoElement A map with containing information for pseudo elements or concatinated elements. The key is comprised of the element symbol and the hydrogen count.
* @param {String} attachedPseudoElement.element The element symbol.
* @param {Number} attachedPseudoElement.count The number of occurences that match the key.
* @param {Number} attachedPseudoElement.hyrogenCount The number of hydrogens attached to each atom matching the key.
*/
drawText(x, y, elementName, hydrogens, direction, isTerminal, charge, isotope, vertexCount, attachedPseudoElement = {}) {
let ctx = this.ctx;
let offsetX = this.offsetX;
let offsetY = this.offsetY;
ctx.save();
ctx.textAlign = 'start';
ctx.textBaseline = 'alphabetic';
let pseudoElementHandled = false;
// Charge
let chargeText = ''
let chargeWidth = 0;
if (charge) {
chargeText = getChargeText(charge);
ctx.font = this.fontSmall;
chargeWidth = ctx.measureText(chargeText).width;
}
let isotopeText = '0';
let isotopeWidth = 0;
if (isotope > 0) {
isotopeText = isotope.toString();
ctx.font = this.fontSmall;
isotopeWidth = ctx.measureText(isotopeText).width;
}
// TODO: Better handle exceptions
// Exception for nitro (draw nitro as NO2 instead of N+O-O)
if (charge === 1 && elementName === 'N' && attachedPseudoElement.hasOwnProperty('0O') &&
attachedPseudoElement.hasOwnProperty('0O-1')) {
attachedPseudoElement = { '0O': { element: 'O', count: 2, hydrogenCount: 0, previousElement: 'C', charge: '' } }
charge = 0;
}
ctx.font = this.fontLarge;
ctx.fillStyle = this.themeManager.getColor('BACKGROUND');
let dim = ctx.measureText(elementName);
dim.totalWidth = dim.width + chargeWidth;
dim.height = parseInt(this.fontLarge, 10);
let r = (dim.width > this.opts.fontSizeLarge) ? dim.width : this.opts.fontSizeLarge;
r /= 1.5;
ctx.globalCompositeOperation = 'destination-out';
ctx.beginPath();
ctx.arc(x + offsetX, y + offsetY, r, 0, MathHelper.twoPI, true);
ctx.closePath();
ctx.fill();
ctx.globalCompositeOperation = 'source-over';
let cursorPos = -dim.width / 2.0;
let cursorPosLeft = -dim.width / 2.0;
ctx.fillStyle = this.themeManager.getColor(elementName);
ctx.fillText(elementName, x + offsetX + cursorPos, y + this.opts.halfFontSizeLarge + offsetY);
cursorPos += dim.width;
if (charge) {
ctx.font = this.fontSmall;
ctx.fillText(chargeText, x + offsetX + cursorPos, y - this.opts.fifthFontSizeSmall + offsetY);
cursorPos += chargeWidth;
}
if (isotope > 0) {
ctx.font = this.fontSmall;
ctx.fillText(isotopeText, x + offsetX + cursorPosLeft - isotopeWidth, y - this.opts.fifthFontSizeSmall + offsetY);
cursorPosLeft -= isotopeWidth;
}
ctx.font = this.fontLarge;
let hydrogenWidth = 0;
let hydrogenCountWidth = 0;
if (hydrogens === 1) {
let hx = x + offsetX;
let hy = y + offsetY + this.opts.halfFontSizeLarge;
hydrogenWidth = this.hydrogenWidth;
cursorPosLeft -= hydrogenWidth;
if (direction === 'left') {
hx += cursorPosLeft;
} else if (direction === 'right') {
hx += cursorPos;
} else if (direction === 'up' && isTerminal) {
hx += cursorPos;
} else if (direction === 'down' && isTerminal) {
hx += cursorPos;
} else if (direction === 'up' && !isTerminal) {
hy -= this.opts.fontSizeLarge + this.opts.quarterFontSizeLarge;
hx -= this.halfHydrogenWidth;
} else if (direction === 'down' && !isTerminal) {
hy += this.opts.fontSizeLarge + this.opts.quarterFontSizeLarge;
hx -= this.halfHydrogenWidth;
}
ctx.fillText('H', hx, hy);
cursorPos += hydrogenWidth;
} else if (hydrogens > 1) {
let hx = x + offsetX;
let hy = y + offsetY + this.opts.halfFontSizeLarge;
hydrogenWidth = this.hydrogenWidth;
ctx.font = this.fontSmall;
hydrogenCountWidth = ctx.measureText(hydrogens).width;
cursorPosLeft -= hydrogenWidth + hydrogenCountWidth;
if (direction === 'left') {
hx += cursorPosLeft;
} else if (direction === 'right') {
hx += cursorPos;
} else if (direction === 'up' && isTerminal) {
hx += cursorPos;
} else if (direction === 'down' && isTerminal) {
hx += cursorPos;
} else if (direction === 'up' && !isTerminal) {
hy -= this.opts.fontSizeLarge + this.opts.quarterFontSizeLarge;
hx -= this.halfHydrogenWidth;
} else if (direction === 'down' && !isTerminal) {
hy += this.opts.fontSizeLarge + this.opts.quarterFontSizeLarge;
hx -= this.halfHydrogenWidth;
}
ctx.font = this.fontLarge;
ctx.fillText('H', hx, hy)
ctx.font = this.fontSmall;
ctx.fillText(hydrogens, hx + this.halfHydrogenWidth + hydrogenCountWidth, hy + this.opts.fifthFontSizeSmall);
cursorPos += hydrogenWidth + this.halfHydrogenWidth + hydrogenCountWidth;
}
if (pseudoElementHandled) {
ctx.restore();
return;
}
for (let key in attachedPseudoElement) {
if (!attachedPseudoElement.hasOwnProperty(key)) {
continue;
}
let openParenthesisWidth = 0;
let closeParenthesisWidth = 0;
let element = attachedPseudoElement[key].element;
let elementCount = attachedPseudoElement[key].count;
let hydrogenCount = attachedPseudoElement[key].hydrogenCount;
let elementCharge = attachedPseudoElement[key].charge;
ctx.font = this.fontLarge;
if (elementCount > 1 && hydrogenCount > 0) {
openParenthesisWidth = ctx.measureText('(').width;
closeParenthesisWidth = ctx.measureText(')').width;
}
let elementWidth = ctx.measureText(element).width;
let elementCountWidth = 0;
let elementChargeText = '';
let elementChargeWidth = 0;
hydrogenWidth = 0;
if (hydrogenCount > 0) {
hydrogenWidth = this.hydrogenWidth;
}
ctx.font = this.fontSmall;
if (elementCount > 1) {
elementCountWidth = ctx.measureText(elementCount).width;
}
if (elementCharge !== 0) {
elementChargeText = getChargeText(elementCharge);
elementChargeWidth = ctx.measureText(elementChargeText).width;
}
hydrogenCountWidth = 0;
if (hydrogenCount > 1) {
hydrogenCountWidth = ctx.measureText(hydrogenCount).width;
}
ctx.font = this.fontLarge;
let hx = x + offsetX;
let hy = y + offsetY + this.opts.halfFontSizeLarge;
ctx.fillStyle = this.themeManager.getColor(element);
if (elementCount > 0) {
cursorPosLeft -= elementCountWidth;
}
if (elementCount > 1 && hydrogenCount > 0) {
if (direction === 'left') {
cursorPosLeft -= closeParenthesisWidth;
ctx.fillText(')', hx + cursorPosLeft, hy);
} else {
ctx.fillText('(', hx + cursorPos, hy);
cursorPos += openParenthesisWidth;
}
}
if (direction === 'left') {
cursorPosLeft -= elementWidth;
ctx.fillText(element, hx + cursorPosLeft, hy)
} else {
ctx.fillText(element, hx + cursorPos, hy)
cursorPos += elementWidth;
}
if (hydrogenCount > 0) {
if (direction === 'left') {
cursorPosLeft -= hydrogenWidth + hydrogenCountWidth;
ctx.fillText('H', hx + cursorPosLeft, hy)
if (hydrogenCount > 1) {
ctx.font = this.fontSmall;
ctx.fillText(hydrogenCount, hx + cursorPosLeft + hydrogenWidth, hy + this.opts.fifthFontSizeSmall);
}
} else {
ctx.fillText('H', hx + cursorPos, hy)
cursorPos += hydrogenWidth;
if (hydrogenCount > 1) {
ctx.font = this.fontSmall;
ctx.fillText(hydrogenCount, hx + cursorPos, hy + this.opts.fifthFontSizeSmall);
cursorPos += hydrogenCountWidth;
}
}
}
ctx.font = this.fontLarge;
if (elementCount > 1 && hydrogenCount > 0) {
if (direction === 'left') {
cursorPosLeft -= openParenthesisWidth;
ctx.fillText('(', hx + cursorPosLeft, hy);
} else {
ctx.fillText(')', hx + cursorPos, hy);
cursorPos += closeParenthesisWidth;
}
}
ctx.font = this.fontSmall;
if (elementCount > 1) {
if (direction === 'left') {
ctx.fillText(elementCount, hx + cursorPosLeft +
openParenthesisWidth + closeParenthesisWidth + hydrogenWidth +
hydrogenCountWidth + elementWidth, hy + this.opts.fifthFontSizeSmall);
} else {
ctx.fillText(elementCount, hx + cursorPos, hy + this.opts.fifthFontSizeSmall);
cursorPos += elementCountWidth;
}
}
if (elementCharge !== 0) {
if (direction === 'left') {
ctx.fillText(elementChargeText, hx + cursorPosLeft +
openParenthesisWidth + closeParenthesisWidth + hydrogenWidth +
hydrogenCountWidth + elementWidth, y - this.opts.fifthFontSizeSmall + offsetY);
} else {
ctx.fillText(elementChargeText, hx + cursorPos, y - this.opts.fifthFontSizeSmall + offsetY);
cursorPos += elementChargeWidth;
}
}
}
ctx.restore();
}
/**
* Translate the integer indicating the charge to the appropriate text.
* @param {Number} charge The integer indicating the charge.
* @returns {String} A string representing a charge.
*/
getChargeText(charge) {
if (charge === 1) {
return '+'
} else if (charge === 2) {
return '2+';
} else if (charge === -1) {
return '-';
} else if (charge === -2) {
return '2-';
} else {
return '';
}
}
/**
* Draws a dubug dot at a given coordinate and adds text.
*
* @param {Number} x The x coordinate.
* @param {Number} y The y coordindate.
* @param {String} [debugText=''] A string.
* @param {String} [color='#f00'] A color in hex form.
*/
drawDebugPoint(x, y, debugText = '', color = '#f00') {
this.drawCircle(x, y, 2, color, true, true, debugText);
}
/**
* Draws a ring inside a provided ring, indicating aromaticity.
*
* @param {Ring} ring A ring.
*/
drawAromaticityRing(ring) {
let ctx = this.ctx;
let radius = MathHelper.apothemFromSideLength(this.opts.bondLength, ring.getSize());
ctx.save();
ctx.strokeStyle = this.themeManager.getColor('C');
ctx.lineWidth = this.opts.bondThickness;
ctx.beginPath();
ctx.arc(ring.center.x + this.offsetX, ring.center.y + this.offsetY,
radius - this.opts.bondSpacing, 0, Math.PI * 2, true);
ctx.closePath();
ctx.stroke();
ctx.restore();
}
/**
* Clear the canvas.
*
*/
clear() {
this.ctx.clearRect(0, 0, this.canvas.offsetWidth, this.canvas.offsetHeight);
}
}
module.exports = CanvasWrapper;