new file mode 100644
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+++ b/gui/src/editor/FileEditorTab.cpp
@@ -0,0 +1,422 @@
+/* OctaveGUI - A graphical user interface for Octave
+ * Copyright (C) 2011 Jacob Dawid (jacob.dawid@googlemail.com)
+ *
+ * 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 3 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/>.
+ */
+
+#include "FileEditorTab.h"
+#include "FileEditor.h"
+#include <QMessageBox>
+#include <QVBoxLayout>
+
+FileEditorTab::FileEditorTab(FileEditor *fileEditor)
+  : QWidget ((QWidget*)fileEditor)
+{
+  QSettings *settings = ResourceManager::instance ()->settings ();
+  m_fileEditor = fileEditor;
+  m_fileName = "";
+  m_editArea = new QsciScintilla (this);
+  m_editArea->setLexer (fileEditor->lexer ());
+
+  // markers
+  m_editArea->setMarginType (1, QsciScintilla::SymbolMargin);
+  m_editArea->setMarginSensitivity (1, true);
+  m_editArea->markerDefine (QsciScintilla::RightTriangle, MARKER_BOOKMARK);
+  connect (m_editArea, SIGNAL (marginClicked (int, int, Qt::KeyboardModifiers)),
+           this, SLOT (handleMarginClicked (int, int, Qt::KeyboardModifiers)));
+
+  // line numbers
+  m_editArea->setMarginsForegroundColor(QColor(96,96,96));
+  m_editArea->setMarginsBackgroundColor(QColor(232,232,220));
+  if (settings->value ("editor/showLineNumbers",true).toBool ())
+    {
+      QFont marginFont( settings->value ("editor/fontName","Courier").toString () ,
+                        settings->value ("editor/fontSize",10).toInt () );
+      m_editArea->setMarginsFont( marginFont );
+      QFontMetrics metrics(marginFont);
+      m_editArea->setMarginType (2, QsciScintilla::TextMargin);
+      m_editArea->setMarginWidth(2, metrics.width("99999"));
+      m_editArea->setMarginLineNumbers(2, true);
+    }
+
+  // code folding
+  m_editArea->setMarginType (3, QsciScintilla::SymbolMargin);
+  m_editArea->setFolding (QsciScintilla::BoxedTreeFoldStyle , 3);
+
+  // other features
+  if (settings->value ("editor/highlightCurrentLine",true).toBool ())
+    {
+      m_editArea->setCaretLineVisible(true);
+      m_editArea->setCaretLineBackgroundColor(QColor(245,245,245));
+    }
+  m_editArea->setBraceMatching (QsciScintilla::StrictBraceMatch);
+  m_editArea->setAutoIndent (true);
+  m_editArea->setIndentationWidth (2);
+  m_editArea->setIndentationsUseTabs (false);
+  if (settings->value ("editor/codeCompletion",true).toBool ())
+    {
+      m_editArea->autoCompleteFromAll ();
+      m_editArea->setAutoCompletionSource(QsciScintilla::AcsAll);
+      m_editArea->setAutoCompletionThreshold (1);
+    }
+  m_editArea->setUtf8 (true);
+
+  QVBoxLayout *layout = new QVBoxLayout ();
+  layout->addWidget (m_editArea);
+  setLayout (layout);
+
+  // connect modified signal
+  connect (m_editArea, SIGNAL (modificationChanged (bool)),
+           this, SLOT (newTitle (bool)));
+  connect (m_editArea, SIGNAL (copyAvailable (bool)),
+           this, SLOT (handleCopyAvailable (bool)));
+
+  m_fileName = "";
+  newTitle (false);
+}
+
+void
+FileEditorTab::closeEvent(QCloseEvent *event)
+{
+  if (m_fileEditor->mainWindow ()->closing ())
+    {
+      // close whole application: save file or not if modified
+      checkFileModified ("Closing Octave", 0); // no cancel possible
+      event->accept ();
+    }
+  else
+    {
+      // ignore close event if file is not saved and user cancels closing this window
+      if (checkFileModified ("Close File",QMessageBox::Cancel) == QMessageBox::Cancel)
+        {
+          event->ignore ();
+        }
+      else
+        {
+          event->accept();
+        }
+    }
+}
+
+void
+FileEditorTab::handleMarginClicked(int margin, int line, Qt::KeyboardModifiers state)
+{
+  Q_UNUSED (state);
+  if (margin == 1)  // marker margin
+    {
+      unsigned int mask = m_editArea->markersAtLine (line);
+      if (mask && (1 << MARKER_BOOKMARK))
+        m_editArea->markerDelete(line,MARKER_BOOKMARK);
+      else
+        m_editArea->markerAdd(line,MARKER_BOOKMARK);
+    }
+}
+
+void
+FileEditorTab::commentSelectedText ()
+{
+  doCommentSelectedText (true);
+}
+
+void
+FileEditorTab::uncommentSelectedText ()
+{
+  doCommentSelectedText (false);
+}
+
+void
+FileEditorTab::doCommentSelectedText (bool comment)
+{
+  if ( m_editArea->hasSelectedText() )
+    {
+      int lineFrom, lineTo, colFrom, colTo, i;
+      m_editArea->getSelection (&lineFrom,&colFrom,&lineTo,&colTo);
+      if ( colTo == 0 )  // the beginning of last line is not selected
+        lineTo--;        // stop at line above
+      m_editArea->beginUndoAction ();
+      for ( i=lineFrom; i<=lineTo; i++ )
+        {
+          if ( comment )
+            m_editArea->insertAt("%",i,0);
+          else
+            {
+              QString line(m_editArea->text(i));
+              if ( line.startsWith("%") )
+                {
+                  m_editArea->setSelection(i,0,i,1);
+                  m_editArea->removeSelectedText();
+                }
+            }
+        }
+      m_editArea->endUndoAction ();
+    }
+}
+
+void
+FileEditorTab::newTitle(bool modified)
+{
+  QString title(m_fileName);
+  if ( !m_longTitle )
+    {
+      QFileInfo file(m_fileName);
+      title = file.fileName();
+    }
+
+  if ( modified )
+    {
+      emit fileNameChanged (title.prepend("* "));
+    }
+  else
+    emit fileNameChanged (title);
+}
+
+void
+FileEditorTab::handleCopyAvailable(bool enableCopy)
+{
+  /*
+  m_copyAction->setEnabled(enableCopy);
+  m_cutAction->setEnabled(enableCopy);
+  */
+}
+
+int
+FileEditorTab::checkFileModified (QString msg, int cancelButton)
+{
+  int decision = QMessageBox::Yes;
+  if (m_editArea->isModified ())
+    {
+      // file is modified but not saved, aks user what to do
+      decision = QMessageBox::warning (this,
+                                       msg,
+                                       tr ("The file %1\n"
+                                           "has been modified. Do you want to save the changes?").
+                                       arg (m_fileName),
+                                       QMessageBox::Save, QMessageBox::Discard, cancelButton );
+      if (decision == QMessageBox::Save)
+        {
+          saveFile ();
+          if (m_editArea->isModified ())
+            {
+              // If the user attempted to save the file, but it's still
+              // modified, then probably something went wrong, so return cancel
+              // for cancel this operation or try to save files as if cancel not
+              // possible
+              if ( cancelButton )
+                return (QMessageBox::Cancel);
+              else
+                saveFileAs ();
+            }
+        }
+    }
+  return (decision);
+}
+
+void
+FileEditorTab::removeBookmark ()
+{
+  m_editArea->markerDeleteAll(MARKER_BOOKMARK);
+}
+
+void
+FileEditorTab::toggleBookmark ()
+{
+  int line,cur;
+  m_editArea->getCursorPosition(&line,&cur);
+  if ( m_editArea->markersAtLine (line) && (1 << MARKER_BOOKMARK) )
+    m_editArea->markerDelete(line,MARKER_BOOKMARK);
+  else
+    m_editArea->markerAdd(line,MARKER_BOOKMARK);
+}
+
+void
+FileEditorTab::nextBookmark ()
+{
+  int line,cur,nextline;
+  m_editArea->getCursorPosition(&line,&cur);
+  if ( m_editArea->markersAtLine(line) && (1 << MARKER_BOOKMARK) )
+    line++; // we have a bookmark here, so start search from next line
+  nextline = m_editArea->markerFindNext(line,(1 << MARKER_BOOKMARK));
+  m_editArea->setCursorPosition(nextline,0);
+}
+
+void
+FileEditorTab::previousBookmark ()
+{
+  int line,cur,prevline;
+  m_editArea->getCursorPosition(&line,&cur);
+  if ( m_editArea->markersAtLine(line) && (1 << MARKER_BOOKMARK) )
+    line--; // we have a bookmark here, so start search from prev line
+  prevline = m_editArea->markerFindPrevious(line,(1 << MARKER_BOOKMARK));
+  m_editArea->setCursorPosition(prevline,0);
+}
+
+void
+FileEditorTab::cut ()
+{
+  m_editArea->cut ();
+}
+
+void
+FileEditorTab::copy ()
+{
+  m_editArea->copy ();
+}
+
+void
+FileEditorTab::paste ()
+{
+  m_editArea->paste ();
+}
+
+void
+FileEditorTab::undo ()
+{
+  m_editArea->undo ();
+}
+
+void
+FileEditorTab::redo ()
+{
+  m_editArea->redo ();
+}
+
+void
+FileEditorTab::setModified (bool modified)
+{
+  m_modified = modified;
+}
+
+void
+FileEditorTab::openFile ()
+{
+  QString openFileName;
+  QFileDialog fileDialog(this);
+  fileDialog.setNameFilter(SAVE_FILE_FILTER);
+  fileDialog.setAcceptMode(QFileDialog::AcceptOpen);
+  fileDialog.setViewMode(QFileDialog::Detail);
+  if ( fileDialog.exec() )
+    {
+      openFileName = fileDialog.selectedFiles().at(0);
+      if (openFileName.isEmpty ())
+        return;
+      loadFile(openFileName);
+    }
+}
+
+void
+FileEditorTab::loadFile (QString fileName)
+{
+  QFile file (fileName);
+  if (!file.open (QFile::ReadOnly))
+    {
+      QMessageBox::warning (this, tr ("Octave Editor"),
+                            tr ("Could not open file %1 for read:\n%2.").arg (fileName).
+                            arg (file.errorString ()));
+      return;
+    }
+
+  QTextStream in (&file);
+  QApplication::setOverrideCursor (Qt::WaitCursor);
+  m_editArea->setText (in.readAll ());
+  QApplication::restoreOverrideCursor ();
+
+  m_fileName = fileName;
+  newTitle (false); // window title (no modification)
+  //m_statusBar->showMessage (tr ("File loaded."), 2000);
+  m_editArea->setModified (false); // loaded file is not modified yet
+}
+
+void
+FileEditorTab::newFile ()
+{
+  m_fileName = UNNAMED_FILE;
+  newTitle (false); // window title (no modification)
+  m_editArea->setText ("");
+  m_editArea->setModified (false); // new file is not modified yet
+}
+
+void
+FileEditorTab::saveFile ()
+{
+  saveFile (m_fileName);
+}
+
+void
+FileEditorTab::saveFile (QString saveFileName)
+{
+  // it is a new file with the name "<unnamed>" -> call saveFielAs
+  if (saveFileName == UNNAMED_FILE || saveFileName.isEmpty ())
+    {
+      saveFileAs();
+      return;
+    }
+
+  // open the file for writing
+  QFile file (saveFileName);
+  if (!file.open (QFile::WriteOnly))
+    {
+      QMessageBox::warning (this, tr ("Octave Editor"),
+                            tr ("Could not open file %1 for write:\n%2.").
+                            arg (saveFileName).arg (file.errorString ()));
+      return;
+    }
+
+  // save the contents into the file
+  QTextStream out (&file);
+  QApplication::setOverrideCursor (Qt::WaitCursor);
+  out << m_editArea->text ();
+  QApplication::restoreOverrideCursor ();
+  m_fileName = saveFileName;  // save file name for later use
+  newTitle (false);      // set the window title to actual file name (not modified)
+  //m_statusBar->showMessage (tr ("File %1 saved").arg(m_fileName), 2000);
+  m_editArea->setModified (false); // files is save -> not modified
+}
+
+void
+FileEditorTab::saveFileAs ()
+{
+  QString saveFileName(m_fileName);
+  QFileDialog fileDialog(this);
+  if (saveFileName == UNNAMED_FILE || saveFileName.isEmpty ())
+    {
+      saveFileName = QDir::homePath ();
+      fileDialog.setDirectory (saveFileName);
+    }
+  else
+    {
+      fileDialog.selectFile (saveFileName);
+    }
+  fileDialog.setNameFilter (SAVE_FILE_FILTER);
+  fileDialog.setDefaultSuffix ("m");
+  fileDialog.setAcceptMode (QFileDialog::AcceptSave);
+  fileDialog.setViewMode (QFileDialog::Detail);
+
+  if (fileDialog.exec ())
+    {
+      saveFileName = fileDialog.selectedFiles ().at (0);
+      if (saveFileName.isEmpty ())
+        return;
+      saveFile (saveFileName);
+    }
+}
+
+void
+FileEditorTab::runFile ()
+{
+  if (m_editArea->isModified ())
+    saveFile(m_fileName);
+
+  m_fileEditor->terminal ()->sendText (QString ("run \'%1\'\n").arg (m_fileName));
+  m_fileEditor->terminal ()->setFocus ();
+}