fractorium/Source/Fractorium/csshighlighter.cpp

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#include "FractoriumPch.h"
#include "csshighlighter.h"

/// <summary>
/// The code in this file did not originate in Fractorium.
/// It was taken either in whole or in part from the source code
/// of Qt Creator. Their license applies.
/// </summary>

CssHighlighter::CssHighlighter(QTextDocument *document)
: QSyntaxHighlighter(document)
{
}

void CssHighlighter::highlightBlock(const QString& text)
{
	enum Token { ALNUM, LBRACE, RBRACE, COLON, SEMICOLON, COMMA, QUOTE, SLASH, STAR };
	static const int transitions[10][9] = {
		{ Selector, Property, Selector, Pseudo,    Property, Selector, Quote, MaybeComment, Selector }, // Selector
		{ Property, Property, Selector, Value,     Property, Property, Quote, MaybeComment, Property }, // Property
		{ Value,    Property, Selector, Value,     Property, Value,    Quote, MaybeComment, Value }, // Value
		{ Pseudo1, Property, Selector, Pseudo2,    Selector, Selector, Quote, MaybeComment, Pseudo }, // Pseudo
		{ Pseudo1, Property, Selector, Pseudo,    Selector, Selector, Quote, MaybeComment, Pseudo1 }, // Pseudo1
		{ Pseudo2, Property, Selector, Pseudo,    Selector, Selector, Quote, MaybeComment, Pseudo2 }, // Pseudo2
		{ Quote,    Quote,    Quote,    Quote,     Quote,    Quote,   -1, Quote, Quote }, // Quote
		{ -1, -1, -1, -1, -1, -1, -1, -1, Comment }, // MaybeComment
		{ Comment, Comment, Comment, Comment, Comment, Comment, Comment, Comment, MaybeCommentEnd }, // Comment
		{ Comment, Comment, Comment, Comment, Comment, Comment, Comment, -1, MaybeCommentEnd } // MaybeCommentEnd
	};

	int lastIndex = 0;
	bool lastWasSlash = false;
	int state = previousBlockState(), save_state;
	if (state == -1) {
		// As long as the text is empty, leave the state undetermined
		if (text.isEmpty()) {
			setCurrentBlockState(-1);
			return;
		}
		// The initial state is based on the precense of a : and the absense of a {.
		// This is because Qt style sheets support both a full stylesheet as well as
		// an inline form with just properties.
		state = save_state = (text.indexOf(QLatin1Char(':')) > -1 &&
							  text.indexOf(QLatin1Char('{')) == -1) ? Property : Selector;
	} else {
		save_state = state>>16;
		state &= 0x00ff;
	}

	if (state == MaybeCommentEnd) {
		state = Comment;
	} else if (state == MaybeComment) {
		state = save_state;
	}

	for (int i = 0; i < text.length(); i++) {
		int token = ALNUM;
		const QChar c = text.at(i);
		const char a = c.toLatin1();

		if (state == Quote) {
			if (a == '\\') {
				lastWasSlash = true;
			} else {
				if (a == '\"' && !lastWasSlash) {
					token = QUOTE;
				}
				lastWasSlash = false;
			}
		} else {
			switch (a) {
			case '{': token = LBRACE; break;
			case '}': token = RBRACE; break;
			case ':': token = COLON; break;
			case ';': token = SEMICOLON; break;
			case ',': token = COMMA; break;
			case '\"': token = QUOTE; break;
			case '/': token = SLASH; break;
			case '*': token = STAR; break;
			default: break;
			}
		}

		int new_state = transitions[state][token];

		if (new_state != state) {
			bool include_token = new_state == MaybeCommentEnd || (state == MaybeCommentEnd && new_state!= Comment)
								 || state == Quote;
			highlight(text, lastIndex, i-lastIndex+include_token, state);

			if (new_state == Comment) {
				lastIndex = i-1; // include the slash and star
			} else {
				lastIndex = i + ((token == ALNUM || new_state == Quote) ? 0 : 1);
			}
		}

		if (new_state == -1) {
			state = save_state;
		} else if (state <= Pseudo2) {
			save_state = state;
			state = new_state;
		} else {
			state = new_state;
		}
	}

	highlight(text, lastIndex, text.length() - lastIndex, state);
	setCurrentBlockState(state + (save_state<<16));
}

void CssHighlighter::highlight(const QString &text, int start, int length, int state)
{
	if (start >= text.length() || length <= 0)
		return;

	QTextCharFormat format;

	switch (state) {
	case Selector:
		setFormat(start, length, QColor::fromRgb(43, 145, 175));//Teal, like the Visual Studio default for classes in C++ and C#.
		break;
	case Property:
		setFormat(start, length, Qt::darkBlue);
		break;
	case Value:
		setFormat(start, length, Qt::black);
		break;
	case Pseudo1:
		setFormat(start, length, Qt::darkRed);
		break;
	case Pseudo2:
		setFormat(start, length, Qt::black);
		break;
	case Quote:
		setFormat(start, length, Qt::darkMagenta);
		break;
	case Comment:
	case MaybeCommentEnd:
		format.setForeground(Qt::darkGreen);
		setFormat(start, length, format);
		break;
	default:
		break;
	}
}