MathQuill

by Han and Jeanine. Current development is proudly supported by Desmos, whose awesome graphing calculator makes extensive use of Mathquill.

Please note that this is a beta version, so bugs and unimplemented features are all over the place.

Usage

(Note: Requires jQuery 1.4.3+. Google CDN-hosted copy recommended.)

To use MathQuill on your website, grab the latest tarball from the downloads page, and serve

• the stylesheet
• the fonts in the font/ directory relative to mathquill.css (or change your copy of mathquill.css to include from the right directory)
• the script (unminified)

then on your webpages include the stylesheet

<link rel="stylesheet" type="text/css" href="/path/to/mathquill.css">`

and after jQuery, the script

<script src="/path/to/mathquill.min.js"></script>

Then wherever you'd like to embed LaTeX math to be rendered in HTML:

<span class="mathquill-embedded-latex">\frac{d}{dx}\sqrt{x}</span>

or have an editable math textbox:

<span class="mathquill-editable">f(x)=?</span>

Note that for dynamically created elements that weren't in the HTML DOM on document ready, you will need to call our jQuery plugin after inserting into the visible HTML DOM:

$('<span>x^2</span>').appendTo('body').mathquill() or .mathquill('editable')

MathQuill has to perform calculations based on computed CSS values. If you mathquill-ify an element before inserting into the visible HTML DOM, then once it is visible MathQuill will need to recalculate:

$('<span>\sqrt{2}</span>').mathquill().appendTo('body').mathquill('redraw')

Any element that has been MathQuill-ified can be reverted:

$('.mathquill-embedded-latex').mathquill('revert');

Manipulating the HTML DOM inside editable math textboxes can break MathQuill. Currently, MathQuill only supports a limited scripting API:

• To access the LaTeX contents of a mathquill-ified element:

    $('<span>x^{-1}</span>').mathquill().mathquill('latex') === 'x^{-1}'
  

• To render some LaTeX in a mathquill-ified element:

    $('<span/>').mathquill().appendTo('body').mathquill('latex','a_n x^n')
  

• To write some LaTeX at the current cursor position:

    someMathQuillifiedElement.mathquill('write','\\frac{d}{dx}')
  

• To insert a LaTeX command at the current cursor position or with the current selection:

    someMathQuillifiedElement.mathquill('cmd','\\sqrt')
  

A Note On Changing Colors:

To change the foreground color, don't just set the color, also set the border-color, because the cursor, fraction bar, and square root overline are all borders, not text. (Example below.)

Due to technical limitations of IE8, if you support it, and want to give a MathQuill editable a background color other than white, and support square roots, parentheses, square brackets, or curly braces, you will need to, in addition to of course setting the background color on the editable itself, set it on elements with class matrixed, and then set a Chroma filter on elements with class matrixed-container.

For example, to style as white-on-black instead of black-on-white:

#my-math-input {
  color: white;
  border-color: white;
  background: black;
}
#my-math-input .matrixed {
  background: black;
}
#my-math-input .matrixed-container {
  filter: progid:DXImageTransform.Microsoft.Chroma(color='black');
}

(This is because almost all math rendered by MathQuill has a transparent background, so for them it's sufficient to set the background color on the editable itself. The exception is, IE8 doesn't support CSS transforms, so MathQuill uses a matrix filter to stretch parens etc, which anti-aliases wrongly without an opaque background, so MathQuill defaults to white.)

Building and Testing

To hack on MathQuill, you're gonna want to build and test the source files you edit. In addition to make, MathQuill uses some build tools written on Node, so you will need to install that before running make. (Once it's installed, make automatically does npm install, installing the necessary build tools.)

• make builds build/mathquill.{css,js,min.js}
• make dev won't try to minify MathQuill (which can be take nonzero time)
• make test also doesn't minify MathQuill, but it also builds mathquill.test.js, which is used in test/unit.html

Understanding The Source Code

All the CSS is in mathquill.css. Most of it's pretty straightforward, the choice of font isn't settled, and fractions are somewhat arcane, see the Wiki pages "Fonts" and "Fractions".

All the JavaScript that you actually want to read is in src/, build/ is created when you run make just to contain a cat'ed and minified version of all that.

Overview of how things fit together:

(Just skim the logic, but do read the starred comments, definitions and method signatures.)

In comments and internal documentation, :: means .prototype..

intro.js defines some simple sugar for the idiomatic JS classes used throughout MathQuill, plus some globals and opening boilerplate.

• Classes are defined using Pjs, and the variable _ is used by convention as the prototype.

tree.js defines the abstract classes for the JS objects that make up the edit tree.

• A Node is a node in the tree.

• A Fragment is a range of siblings in the tree. This is used, for example, for selections.

• The edit tree has two kinds of nodes: commands and blocks

  • blocks, like the root block, can contain any number of commands
  • commands, like x, 1, +, \frac, \sqrt (clearly siblings in the tree) contain a fixed number of blocks
    • symbols like x, y, 1, 2, +, - are commands with 0 blocks

• All edit tree nodes are instances of MathElement

  • blocks are instances of MathBlock
  • commands are instances of MathCommand
    • symbols are instances of Symbol

cursor.js defines the "singleton" classes for the visible blinking cursor and highlighted selection.

• The methods on Cursor pretty much do what they say on the tin. They're how the tree is supposed to traversed and modified.

rootelements.js defines the edit tree root elements, and a function createRoot() that attaches event handlers to the jQuery-wrapped HTML elements:

• Some root elements can actually be in others, so rather than attaching handlers in the constructor, createRoot() is called on the actual root element. Except \editable{}s need text input event handlers that aren't attached to the static math containing them...it's a little messy.
• Event delegation is used in 2 ways:
  • in the HTML DOM, the root span element of each MathQuill thing is delegated all the events in it's own MathQuill thing
    • keyboard events usually end up triggering their analogue in the edit tree on the cursor, which then bubble upwards
  • in the edit tree, the root MathElement is delegated most of these virtual keyboard events
    • for example, RootMathBlock::keydown()
    • some special commands do intercept these events, though

textarea.js handles all the HTML DOM events necessary to emulate a textarea, using a hidden textarea.

symbols.js defines classes for all the symbols like & and \partial, and adds the constructors to CharCmds or LatexCmds as used by Cursor::write().

commands.js defines classes for all the commands like \frac and /, and adds the constructors to CharCmds or LatexCmds.

publicapi.js defines the public jQuery::mathquill() method and on document ready, finds and mathquill-ifies .mathquill-editable and so on elements.

outro.js is just closing boilerplate to match that in intro.js.

Open-Source License

The Source Code Form of MathQuill is subject to the terms of the Mozilla Public License, v. 2.0: http://mozilla.org/MPL/2.0/

The quick-and-dirty is you can do whatever if modifications to MathQuill are in public GitHub forks.

Other ways to publicize modifications are also fine, as are private use modifications. See also: MPL 2.0 FAQ