Improvements for working in the SQL Execution area using keyboard

This addresses two issued mentioned in #2215
# It's possible to focus out of the SQL Editor using Ctrl+PgDown (not used
by QScintilla)
# Ctrl+Tab and Ctrl+Shift+Tab works in all the widgets in the area and
provides the same functionality that the one provided by QTabWidget
(switch for- and backwards through the tabs)

src/MainWindow.cpp

@@ -221,6 +221,28 @@ void MainWindow::init()
           closeSqlTab(ui->tabSqlAreas->currentIndex());
     });
 
+    // Shortcuts for advancing and going back in the SQL Execution area tabs, independently of the widget which has focus.
+    // This emulates the shortcuts provided by QTabWidget.
+    QShortcut* shortcutNextTab = new QShortcut(QKeySequence(tr("Ctrl+Tab")), ui->tabSqlAreas, nullptr, nullptr, Qt::WidgetWithChildrenShortcut);
+    connect(shortcutNextTab, &QShortcut::activated, this, [this]() {
+        if(ui->tabSqlAreas->currentIndex() == ui->tabSqlAreas->count() - 1)
+            ui->tabSqlAreas->setCurrentIndex(0);
+        else
+            ui->tabSqlAreas->setCurrentIndex(ui->tabSqlAreas->currentIndex() + 1);
+        SqlExecutionArea* sqlWidget = qobject_cast<SqlExecutionArea*>(ui->tabSqlAreas->currentWidget());
+        sqlWidget->getEditor()->setFocus();
+    });
+
+    QShortcut* shortcutPreviousTab = new QShortcut(QKeySequence(tr("Ctrl+Shift+Tab")), ui->tabSqlAreas, nullptr, nullptr, Qt::WidgetWithChildrenShortcut);
+    connect(shortcutPreviousTab, &QShortcut::activated, this, [this]() {
+        if(ui->tabSqlAreas->currentIndex() == 0)
+            ui->tabSqlAreas->setCurrentIndex(ui->tabSqlAreas->count() - 1);
+        else
+            ui->tabSqlAreas->setCurrentIndex(ui->tabSqlAreas->currentIndex() - 1);
+        SqlExecutionArea* sqlWidget = qobject_cast<SqlExecutionArea*>(ui->tabSqlAreas->currentWidget());
+        sqlWidget->getEditor()->setFocus();
+    });
+
     // Create the actions for the recently opened dbs list
     for(int i = 0; i < MaxRecentFiles; ++i) {
         recentFileActs[i] = new QAction(this);

src/sqltextedit.cpp

@@ -41,6 +41,9 @@ SqlTextEdit::SqlTextEdit(QWidget* parent) :
     QShortcut* shortcutToggleComment = new QShortcut(QKeySequence(tr("Ctrl+/")), this, nullptr, nullptr, Qt::WidgetShortcut);
     connect(shortcutToggleComment, &QShortcut::activated, this, &SqlTextEdit::toggleBlockComment);
 
+    QShortcut* shortcutFocusOut = new QShortcut(QKeySequence(tr("Ctrl+PgDown")), this, nullptr, nullptr, Qt::WidgetShortcut);
+    connect(shortcutFocusOut, &QShortcut::activated, this, &SqlTextEdit::transferFocus);
+
     // Do rest of initialisation
     reloadSettings();
 }
@@ -133,3 +136,9 @@ void SqlTextEdit::toggleBlockComment()
     }
     endUndoAction();
 }
+
+void SqlTextEdit::transferFocus()
+{
+    // We need two jumps to get to the Table Results widget
+    nextInFocusChain()->nextInFocusChain()->setFocus();
+}

src/sqltextedit.h

@@ -18,6 +18,9 @@ public:
 
     static SqlUiLexer* sqlLexer;
 
+private:
+    void transferFocus();
+
 public slots:
     void reloadSettings();
     void toggleBlockComment();