initial commit

src/tabcompletion.cpp

@@ -0,0 +1,246 @@
+/*
+ * Copyright (C) 2001-2008 Justin Karneges, Martin Hostettler
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+ // Generic tab completion support code.
+
+#include <QDebug>
+#include "tabcompletion.h"
+
+TabCompletion::TabCompletion(QObject *parent)
+ : QObject(parent)
+{
+	typingStatus_ = Typing_Normal;
+	textEdit_ = 0;
+}
+
+
+TabCompletion::~TabCompletion()
+{
+}
+
+void TabCompletion::setTextEdit(QTextEdit* textEdit) {
+	textEdit_ = textEdit;
+
+	QColor mleBackground(textEdit_->palette().color(QPalette::Active, QPalette::Base));
+
+	if (mleBackground.value() < 128) {
+		highlight_ = mleBackground.lighter(125);
+	} else {
+		highlight_ = mleBackground.darker(125);
+	}
+}
+
+QTextEdit* TabCompletion::getTextEdit() {
+	return textEdit_;
+}
+
+
+void TabCompletion::highlight(bool set) {
+	Q_UNUSED(set);
+/*
+	if (set) {
+		QTextEdit::ExtraSelection es;
+		es.cursor = replacementCursor_;
+		es.format.setBackground(highlight_);
+		textEdit_->setExtraSelections(QList<QTextEdit::ExtraSelection>() << es);
+	} else {
+		if (textEdit_) textEdit_->setExtraSelections(QList<QTextEdit::ExtraSelection>());
+	}*/
+}
+
+
+
+
+void TabCompletion::moveCursorToOffset(QTextCursor &cur, int offset, QTextCursor::MoveMode mode) {
+	cur.movePosition(QTextCursor::Start, mode);
+	for (int i = 0; i < offset; i++) { // some sane limit on iterations
+		if (cur.position() >= offset) break; // done our work
+		if (!cur.movePosition(QTextCursor::NextCharacter, mode)) break; // failed?
+	}
+}
+
+
+
+/** Find longest common (case insensitive) prefix of \a list.
+	*/
+QString TabCompletion::longestCommonPrefix(QStringList list) {
+	QString candidate = list.first().toLower();
+	int len = candidate.length();
+	while (len > 0) {
+		bool found = true;
+		foreach(QString str, list) {
+			if (str.left(len).toLower() != candidate) {
+				found = false;
+				break;
+			}
+		}
+
+		if (found) {
+			break;
+		}
+
+		--len;
+		candidate = candidate.left(len);
+	}
+	return candidate;
+}
+
+void TabCompletion::setup(QString text, int pos, int &start, int &end) {
+	if (text.isEmpty() || pos==0) {
+		atStart_ = true;
+		toComplete_ = "";
+		start = 0;
+		end = 0;
+		return;
+	}
+	end = pos;
+	int i;
+	for (i = pos - 1; i > 0; --i) {
+		if (text[i].isSpace()) {
+			break;
+		}
+	}
+	if (!text[i].isSpace()) {
+		atStart_ = true;
+		start = 0;
+	} else {
+		atStart_ = false;
+		start = i+1;
+	}
+	toComplete_ = text.mid(start, end-start);
+}
+
+
+
+
+QString TabCompletion::suggestCompletion(bool *replaced) {
+
+	suggestedCompletion_ = possibleCompletions();
+	suggestedIndex_ = -1;
+
+	QString newText;
+	if (suggestedCompletion_.count() == 1) {
+		*replaced = true;
+		newText = suggestedCompletion_.first();
+	} else if (suggestedCompletion_.count() > 1) {
+		newText = longestCommonPrefix(suggestedCompletion_);
+		if (newText.isEmpty()) {
+			return toComplete_; // FIXME is this right?
+		}
+
+		typingStatus_ = Typing_MultipleSuggestions;
+		// TODO: display a tooltip that will contain all suggestedCompletion
+		*replaced = true;
+	}
+
+
+	return newText;
+}
+
+
+
+void TabCompletion::reset() {
+	typingStatus_ = Typing_Normal;
+	highlight(false);
+}
+
+/** Handle tab completion.
+	* User interface uses a dual model, first tab completes upto the
+	* longest common (case insensitiv) match, further tabbing cycles through all
+	* possible completions. When doing a tab completion without something to complete
+	* possibly offers a special guess first.
+	*/
+void TabCompletion::tryComplete() {
+	switch (typingStatus_) {
+		case Typing_Normal:
+			typingStatus_ = Typing_TabPressed;
+			break;
+		case Typing_TabPressed:
+			typingStatus_ = Typing_TabbingCompletions;
+			break;
+		default:
+			break;
+	}
+
+
+	QString newText;
+	bool replaced = false;
+
+	if (typingStatus_ == Typing_MultipleSuggestions) {
+		if (!suggestedCompletion_.isEmpty()) {
+			suggestedIndex_++;
+			if (suggestedIndex_ >= (int)suggestedCompletion_.count()) {
+				suggestedIndex_ = 0;
+			}
+			newText = suggestedCompletion_[suggestedIndex_];
+			replaced = true;
+		}
+	} else {
+		QTextCursor cursor = textEdit_->textCursor();
+		QString wholeText = textEdit_->toPlainText();
+
+		int begin, end;
+		setup(wholeText, cursor.position(), begin, end);
+		replacementCursor_ = QTextCursor(textEdit_->document());
+		moveCursorToOffset(replacementCursor_, begin);
+		moveCursorToOffset(replacementCursor_, end, QTextCursor::KeepAnchor);
+
+		if (toComplete_.isEmpty() && typingStatus_ == Typing_TabbingCompletions) {
+			typingStatus_ = Typing_MultipleSuggestions;
+
+			QString guess;
+			suggestedCompletion_ = allChoices(guess);
+
+			if ( !guess.isEmpty() ) {
+				suggestedIndex_ = -1;
+				newText = guess;
+				replaced = true;
+			} else if (!suggestedCompletion_.isEmpty()) {
+				suggestedIndex_ = 0;
+				newText = suggestedCompletion_.first();
+				replaced = true;
+			}
+		} else {
+			newText = suggestCompletion(&replaced);
+		}
+	}
+
+	if (replaced) {
+		textEdit_->setUpdatesEnabled(false);
+
+		int start = qMin(replacementCursor_.anchor(), replacementCursor_.position());
+
+		replacementCursor_.beginEditBlock();
+		replacementCursor_.insertText(newText);
+		replacementCursor_.endEditBlock();
+
+		QTextCursor newPos(replacementCursor_);
+
+		moveCursorToOffset(replacementCursor_, start, QTextCursor::KeepAnchor);
+
+
+		newPos.clearSelection();
+
+		textEdit_->setTextCursor(newPos);
+
+		textEdit_->setUpdatesEnabled(true);
+		textEdit_->viewport()->update();
+	}
+	highlight(typingStatus_ == Typing_MultipleSuggestions);
+}
+