Hi! Thank you for this project, I really like it!

I needed a way to render LaTeX equations for another project (VectSharp.Markdown), and this seemed like a good place to start.

To be able to make it work with my project, I have created a new front end for CSharpMath, which uses VectSharp to render the equations. As a side effect, this makes it possible to output the rendered LaTeX to SVG and PDF documents, as well as to raster images.

For example, to render an equation to an SVG file (requires the VectSharp.SVG NuGet package):

using VectSharp;
using VectSharp.SVG;
using CSharpMath.VectSharp;

var painter = new MathPainter();
painter.LaTeX = @"\left( \sum_{k=1}^n a_k b_k \right)^2 \leq \left( \sum_{k=1}^n a_k^2 \right) \left( \sum_{k=1}^n b_k^2 \right)";

Page pag = painter.DrawToPage();
pag.SaveAsSVG("test.svg");

Or to a PDF file (requires the VectSharp.PDF NuGet package):

using VectSharp;
using VectSharp.PDF;
using CSharpMath.VectSharp;

var painter = new MathPainter();
painter.LaTeX = @"\left( \sum_{k=1}^n a_k b_k \right)^2 \leq \left( \sum_{k=1}^n a_k^2 \right) \left( \sum_{k=1}^n b_k^2 \right)";

Page pag = painter.DrawToPage();
Document doc = new Document();
doc.Pages.Add(pag);

doc.SaveAsPDF("test.pdf");

Currently, this implementation is very similar to the CSharpMath.SkiaSharp implementation, except that it uses VectSharp rather than SkiaSharp for rendering. Ideally, at some point in the future I would like to fork from CSharpMath.Rendering in order to directly draw the glyphs, which would have the added benefit of making text selectable in PDF files. It will take some time though, because at the very least I need to implement a parser for the MATH OpenType table.

I hope this can be useful! Let me know if there are any issues or you have any questions!

Remove a usage of Enum.GetValues, which is based on reflection and not trim compatible.

Fixes #227

The main goal of this commit is to make keyboard colors customizable (per keyboard key) to fit an app's color theme(s). For example, a dark keyboard background with light button texts.

CSharpMath.Forms:

• Refactor BaseButton's constructor.
• Add TextColor property to BaseButton and a bindable TextColorProperty.
• Remove the predefined Red color from MathInputButton.InputToLaTeX(input) for "Backspace" and "Clear".

CSharpMath.Forms.Example (MathKeyboard.xaml):

• Use the TextColorProperty in the Style of "Backspace" and "Clear", setting it to Red.

So that

class RussianBreakingEngine : Typography.TextBreak.EngBreakingEngine {
  public override bool CanHandle(char c) => c is >= '\u0400' and <= '\u052f'; // Unicode Cyrillic and Cyrillic Supplement
}
CSharpMath.Rendering.Text.TextLaTeXParser.AdditionalBreakingEngines.Add(new RussianBreakingEngine());

can be used for #192 while awaiting Typography support.

• Build /
• Test / Core [ workaround ]

For Test / Core I had to change version for Avalonia.Skia package manually since I didn't find any good (and easy to implement) way to specify the same version of Avalonia.

Also I turned off (temporarily) automatic updates for Avalonia.Skia package.

Test / Ios is unrelated.

In issue #175 a feature request was done for stopping the blinking of the placeholder (but still have a blinking carret if it moves to a spot without a placeholder).

The proposed pull request #176 just removes the blinking of the placeholder and does not leave it as an option.

This pull request adds a setting LaTeXSetting.PlaceholderBlinks that keeps the default value true and does not break any existing unit tests.

Tests are added

• to make sure that the setting for a non-blinking placeholder works
• to document how it should work
• to make sure that it will not be removed in a whim

@charlesroddie Please verify that the effect of changing the "PlaceholderBlinks"-setting results in the behaviour you like.

In pull request #164, posting #164 (comment), the idea came up to make the placeholder customizable in the keyboard output. While PR #164 is concerned with the display of the keyboard buttons themselves, this PR is about the math keyboard output.

Currently the placeholder has two possible appearances: a full black square and an empty square with a black border.

This pull request makes the Nucleus and the ForeColor of the placeholder customizable in both CaretStates.

An example of usage: instead of an empty square with a black border in the 'hiding' CaretState, you could choose a full square with another Color (gray, for instance).

An example test:
In CSharpMath.Forms.Example\CSharpMath.Forms.Example\EditorPage.xaml.cs
add the following lines at the top of the constructor of the EditorView:

      Atom.LaTeXSettings.PlaceholderHidingNucleus = "\u25A0";
      Atom.LaTeXSettings.PlaceholderHidingColor = Color.LightGray;

Open the Example project and go to the Editor tab. Click the fraction button. The output is:

where the square in the numerator blinks, LightGray/Black.

I am willing to write unit tests after some form of preliminary approval of this pull request.
(And of course I will fix mistakes and refactor if needed.)

Initial simplification in preparation for adding Font Styles

• DoNothingFontChanger was removed was only used in tests.

For subsequent PR:

• UnicodeFontChanger uses "mathematical bold/italic" ranges to use a single font for normal/bold/italic. To preserve existing functionality without deploying additional fonts, this logic needs to be kept when using standard fonts.
• Allow users to add bold and italic fonts, for use in TextPainter. This PR will not address MathAtom fonts. If these fonts are present, they will be used instead of UnicodeFontChanger for rendering bold/italic fonts.

Also CSharpMath.Rendering.Tests baselines became smaller magically

Also added a calculator to Avalonia Example

Now every command is put into a central place for lookup.

Also added \atopwithdelims to let MathListFromLaTeX be able to consume MathListToLaTeX output, and % for comments are now supported in MathListFromLaTeX and MathListToLaTeX.

AliasDictionary has been split into BiDictionary and ProxyAdder.

Contributes to #58.

Reduce code by removing a Color structure that duplicates System.Drawing.Color. Presumably this predated netstandard.

This pull request adds the \bra{} and \ket{} commands, which are useful shorthand commands for work involving quantum mechanics and Dirac notation.

Example of a common use case:

Their implementation is inspired by the popular braket LaTeX package.

Part of a series of PRs on fixing #32

• Fixed large space above large matrices
• Fixed several parsing bugs like \left( x\\ y\right) which round-tripped to \left( x\\ y&\right)
• Better error messages for \begin \end and \left \right pairs
• And refactorings

According to AMSMath documentation, ! should be of Class Punctuation instead of Close. Not sure why ? and ! are classified as Close which brings complexity when dealing with brackets.

Changes

• Updated Avalonia to 0.10.0-preview1:
  • Updated default text color and font size:
    • Text color is now based on fluent theme resources (won't work for default theme, which I think will be deprecated soon anyway).
    • Font size is now constant 14.0f (this value comes from fluent theme resources, there is also a bug which blocks using the resource: it is double, but font size is float, probably a bug in Avalonia).
  • Updated Avalonia sample:
    • Also removed SideBar.xaml: the default styles for TabControl is good in fluent theme, also the side bar styles don't look good in fluent.

Comment out specific problematic test cases instead of skipping the whole test

Also fixed CSharpMath.Ios.Tests.MathInline not actually being inline

Also enabled artifact uploading of image test results.

A better way of comparing images will be needed, as image size comparisons are unreliable.

Per dotnet/sourcelink#255, non-NuGet feeds do not support .snupkgs, so they are not available for CI packages.