First version of multiple SQL scripts support in main window

Allow multiple SQL scripts in different tabs in the SQL tab of the main
window.

Auto completion support is still missing, the rest is working fine.

src/SqlExecutionArea.cpp

@@ -0,0 +1,62 @@
+#include "SqlExecutionArea.h"
+#include "sqltextedit.h"
+#include "ExtendedTableWidget.h"
+#include "SQLiteSyntaxHighlighter.h"
+#include "sqlitetablemodel.h"
+#include "sqlitedb.h"
+#include "PreferencesDialog.h"
+#include <QLabel>
+#include <QSplitter>
+#include <QVBoxLayout>
+
+SqlExecutionArea::SqlExecutionArea(QWidget* parent, DBBrowserDB* db) :
+    QFrame(parent)
+{
+    // Create widgets
+    splitter = new QSplitter(Qt::Vertical, this);
+    editor = new SqlTextEdit(this);
+    table = new ExtendedTableWidget(this);
+    errors = new QLabel(this);
+
+    // Set up widgets
+    QFont font("Monospace");
+    font.setStyleHint(QFont::TypeWriter);
+    font.setPointSize(8);
+    editor->setFont(font);
+
+    highlighter = new SQLiteSyntaxHighlighter(editor->document());
+
+    model = new SqliteTableModel(this, db, PreferencesDialog::getSettingsValue("db", "prefetchsize").toInt());
+    table->setModel(model);
+
+    // Build layout
+    splitter->addWidget(editor);
+    splitter->addWidget(table);
+
+    layout = new QVBoxLayout(this);
+    layout->addWidget(splitter);
+    layout->addWidget(errors);
+
+    setLayout(layout);
+}
+
+void SqlExecutionArea::setTableNames(const QStringList& tables)
+{
+    highlighter->setTableNames(tables);
+}
+
+QString SqlExecutionArea::getSql() const
+{
+    return editor->toPlainText().trimmed();
+}
+
+QString SqlExecutionArea::getSelectedSql() const
+{
+    return editor->textCursor().selectedText().trimmed();
+}
+
+void SqlExecutionArea::finishExecution(const QString& result)
+{
+    errors->setText(result);
+    table->resizeColumnsToContents();
+}