MKleusberg · Nov 8, 2018 · Oct 11, 2018
diff --git a/src/MainWindow.cpp b/src/MainWindow.cpp
@@ -286,6 +286,20 @@ void MainWindow::init()
 #endif
 
     // Set statusbar fields
+    statusBusyLabel = new QLabel(ui->statusbar);
+    statusBusyLabel->setEnabled(false);
+    statusBusyLabel->setVisible(false);
+    statusBusyLabel->setToolTip(tr("The database is currenctly busy."));
+    ui->statusbar->addPermanentWidget(statusBusyLabel);
+
+    statusStopButton = new QToolButton(ui->statusbar);
+    statusStopButton->setVisible(false);
+    statusStopButton->setIcon(QIcon(":icons/cancel"));
+    statusStopButton->setToolTip(tr("Click here to interrupt the currently running query."));
+    statusStopButton->setMaximumSize(ui->statusbar->geometry().height() - 6, ui->statusbar->geometry().height() - 6);
+    statusStopButton->setAutoRaise(true);
+    ui->statusbar->addPermanentWidget(statusStopButton);
+
     statusEncryptionLabel = new QLabel(ui->statusbar);
     statusEncryptionLabel->setEnabled(false);
     statusEncryptionLabel->setVisible(false);
@@ -316,6 +330,11 @@ void MainWindow::init()
         ui->editDeleteObjectAction->setToolTip(ui->editDeleteObjectAction->text());
     });
 
+    // When clicking the interrupt query button in the status bar, ask SQLite to interrupt the current query
+    connect(statusStopButton, &QToolButton::clicked, [this]() {
+       db.interruptQuery();
+    });
+
     // Connect some more signals and slots
     connect(ui->dataTable->filterHeader(), SIGNAL(sectionClicked(int)), this, SLOT(browseTableHeaderClicked(int)));
     connect(ui->dataTable->verticalScrollBar(), SIGNAL(valueChanged(int)), this, SLOT(setRecordsetLabel()));
@@ -332,6 +351,8 @@ void MainWindow::init()
     connect(ui->dataTable, &ExtendedTableWidget::selectedRowsToBeDeleted, this, &MainWindow::deleteRecord);
     connect(ui->actionDropQualifiedCheck, &QAction::toggled, dbStructureModel, &DbStructureModel::setDropQualifiedNames);
     connect(ui->actionEnquoteNamesCheck, &QAction::toggled, dbStructureModel, &DbStructureModel::setDropEnquotedNames);
+    connect(&db, &DBBrowserDB::databaseInUseChanged, this, &MainWindow::updateDatabaseBusyStatus);
+
     ui->actionDropQualifiedCheck->setChecked(Settings::getValue("SchemaDock", "dropQualifiedNames").toBool());
     ui->actionEnquoteNamesCheck->setChecked(Settings::getValue("SchemaDock", "dropEnquotedNames").toBool());
 
@@ -3541,3 +3562,10 @@ void MainWindow::printDbStructure ()
     delete dialog;
     delete document;
 }
+
+void MainWindow::updateDatabaseBusyStatus(bool busy, const QString& user)
+{
+    statusBusyLabel->setText(tr("Busy (%1)").arg(user));
+    statusBusyLabel->setVisible(busy);
+    statusStopButton->setVisible(busy);
+}
diff --git a/src/MainWindow.h b/src/MainWindow.h
@@ -7,19 +7,21 @@
 #include <QMainWindow>
 #include <QMap>
 
-class QDragEnterEvent;
 class EditDialog;
-class QIntValidator;
-class QLabel;
-class QModelIndex;
-class QPersistentModelIndex;
 class SqliteTableModel;
 class DbStructureModel;
 class RemoteDock;
 class RemoteDatabase;
 class FindReplaceDialog;
 class ExtendedTableWidget;
 
+class QDragEnterEvent;
+class QIntValidator;
+class QModelIndex;
+class QLabel;
+class QPersistentModelIndex;
+class QToolButton;
+
 namespace Ui {
 class MainWindow;
 }
@@ -157,6 +159,8 @@ class MainWindow : public QMainWindow
     QLabel* statusEncodingLabel;
     QLabel* statusEncryptionLabel;
     QLabel* statusReadOnlyLabel;
+    QToolButton* statusStopButton;
+    QLabel* statusBusyLabel;
 
     DbStructureModel* dbStructureModel;
 
@@ -301,6 +305,7 @@ private slots:
     void updateInsertDeleteRecordButton();
     void runSqlNewTab(const QString& query, const QString& title);
     void printDbStructure();
+    void updateDatabaseBusyStatus(bool busy, const QString& user);
 };
 
 #endif
diff --git a/src/icons/cancel.png b/src/icons/cancel.png
diff --git a/src/icons/icons.qrc b/src/icons/icons.qrc
@@ -68,5 +68,6 @@
         <file alias="text_indent">text_indent.png</file>
         <file alias="print">printer.png</file>
         <file alias="project_save">package_save.png</file>
+        <file alias="cancel">cancel.png</file>
     </qresource>
 </RCC>
diff --git a/src/sqlitedb.cpp b/src/sqlitedb.cpp
@@ -608,6 +608,7 @@ DBBrowserDB::db_pointer_type DBBrowserDB::get(QString user)
 
     db_user = user;
     db_used = true;
+    emit databaseInUseChanged(true, user);
 
     return db_pointer_type(_db, DatabaseReleaser(this));
 }
@@ -1871,3 +1872,11 @@ QString DBBrowserDB::generateTemporaryTableName(const QString& schema) const
             return table_name;
     }
 }
+
+void DBBrowserDB::interruptQuery()
+{
+    if(!_db)
+        return;
+
+    sqlite3_interrupt(_db);
+}
diff --git a/src/sqlitedb.h b/src/sqlitedb.h
@@ -48,6 +48,7 @@ class DBBrowserDB : public QObject
             std::unique_lock<std::mutex> lk(pParent->m);
             pParent->db_used = false;
             lk.unlock();
+            emit pParent->databaseInUseChanged(false, QString());
             pParent->cv.notify_one();
         }
     };
@@ -111,6 +112,11 @@ class DBBrowserDB : public QObject
      */
     bool getRow(const sqlb::ObjectIdentifier& table, const QString& rowid, QVector<QByteArray>& rowdata);
 
+    /**
+     * @brief Interrupts the currenty running statement as soon as possible.
+     */
+    void interruptQuery();
+
 private:
     /**
      * @brief max Queries the table t for the max value of field.
@@ -202,6 +208,7 @@ class DBBrowserDB : public QObject
     void dbChanged(bool dirty);
     void structureUpdated();
     void requestCollation(QString name, int eTextRep);
+    void databaseInUseChanged(bool busy, QString user);
 
 private:
     /// external code needs to go through get() to obtain access to the database