chore(web): cleanup & segmentation of font style-sheet management

[jahorton]

As of the changes in #7343 and #7360, there are a couple of lingering references to old touch-alias code still found in kmwbase.ts:

keyman/web/source/kmwbase.ts

Lines 53 to 58 in 312b19c

	export class KeymanBase {
	_MasterDocument = null; // Document with controller (to allow iframes to distinguish local/master control)
	_HotKeys = []; // Array of document-level hotkey objects
	warned = false; // Warning flag (to prevent multiple warnings)
	baseFont = 'sans-serif'; // Default font for mapped input elements
	appliedFont = ''; // Chain of fonts to be applied to mapped input elements

As it stands, baseFont and appliedFont are still in use - most prominently by the following methods:

• VisualKeyboard.appendStyleSheet()
• Which calls VisualKeyboard.addFontStyle()

There's also some setup code to prepare appliedFont for use there, based on the value assigned during engine init to baseFont.

For VisualKeyboard.addFontStyle():

keyman/web/source/osk/visualKeyboard.ts

Lines 1371 to 1414 in 312b19c

	addFontStyle(kfd, ofd): string {
	let keymanweb = com.keyman.singleton;
	// Get name of font to be applied
	var fn = keymanweb.baseFont;
	if (typeof (kfd) != 'undefined' && typeof (kfd['family']) != 'undefined') {
	fn = kfd['family'];
	}
	// Unquote font name in base font (if quoted)
	fn = fn.replace(/\u0022/g, '');
	// Set font family chain for mapped elements and remove any double quotes
	var rx = new RegExp('\\s?' + fn + ',?'), ff = keymanweb.appliedFont.replace(/\u0022/g, '');
	// Remove base font name from chain if present
	ff = ff.replace(rx, '');
	ff = ff.replace(/,$/, '');
	// Then replace it at the head of the chain
	if (ff == '') {
	ff = fn;
	} else {
	ff = fn + ',' + ff;
	}
	// Re-insert quotes around individual font names
	ff = '"' + ff.replace(/\,\s?/g, '","') + '"';
	// Add to the stylesheet, quoted, and with !important to override any explicit style
	var s = '.keymanweb-font{\nfont-family:' + ff + ' !important;\n}\n';
	// Set font family for OSK text
	if (typeof (ofd) != 'undefined') {
	s = s + '.kmw-key-text{\nfont-family:"' + ofd['family'].replace(/\u0022/g, '').replace(/,/g, '","') + '";\n}\n';
	} else if (typeof (kfd) != 'undefined') {
	s = s + '.kmw-key-text{\nfont-family:"' + kfd['family'].replace(/\u0022/g, '').replace(/,/g, '","') + '";\n}\n';
	}
	// Store the current font chain (with quote-delimited font names)
	keymanweb.appliedFont = ff;
	// Return the style string
	return s;

Note that the function accomplishes two separate goals in the same function:

• Prepares OSK key font formatting.
  • This quite clearly belongs here.
  • This currently does reference baseFont, though there's little reason the OSK can't do an independent, quick check rather than rely on this "semi-global". (In fact, relying on it hurts a goal referenced below - the "own module" bit.)
• Prepares CSS font formatting for page inputs for browser-based KMW.
  • This... should be separate. There's no need for it to be here.
  • If we're planning to spin the OSK off as its own module (like, for cross-platform keyboard theming), this part should be left out as browser-Web-only.
  • Note: appliedFont is only used for this purpose. The OSK does not need access to this variable otherwise.