Automatically refresh read-only databases on modified database file

mgrojo · mgrojo · commit 6ec047a66360 · 2026-03-28T20:41:00.000+01:00
This adds a new setting in "Preferences > Database" (defaulting to false) to watch the database file when opened in read-only mode and refresh the browser on updated file. See issues #1767 and #2508.
diff --git a/src/MainWindow.cpp b/src/MainWindow.cpp
@@ -583,7 +583,11 @@ bool MainWindow::fileOpen(const QString& fileName, bool openFromProject, bool re
                     loadPragmas();
 
                 refreshTableBrowsers();
-
+                if (db.readOnly()) {
+                    if (!fileSystemWatch.files().isEmpty())
+                        fileSystemWatch.removePaths(fileSystemWatch.files());
+                    fileSystemWatch.addPath(wFile);
+                }
                 retval = true;
             } else {
                 QMessageBox::warning(this, qApp->applicationName(), tr("Could not open database file.\nReason: %1").arg(db.lastError()));
@@ -700,6 +704,10 @@ void MainWindow::refreshTableBrowsers(bool all)
     QApplication::restoreOverrideCursor();
 }
 
+void MainWindow::refreshDb() {
+    refreshTableBrowsers();
+}
+
 bool MainWindow::fileSaveAs() {
 
     QString fileName =  FileDialog::getSaveFileName(
@@ -743,6 +751,8 @@ bool MainWindow::fileClose()
     if(!db.close())
         return false;
 
+    if (!fileSystemWatch.files().isEmpty())
+        fileSystemWatch.removePaths(fileSystemWatch.files());
     TableBrowser::resetSharedSettings();
     setCurrentFile(QString());
     loadPragmas();
@@ -2462,6 +2472,14 @@ void MainWindow::reloadSettings()
 
     ui->actionDropQualifiedCheck->setChecked(Settings::getValue("SchemaDock", "dropQualifiedNames").toBool());
     ui->actionEnquoteNamesCheck->setChecked(Settings::getValue("SchemaDock", "dropEnquotedNames").toBool());
+
+    if (Settings::getValue("db", "watcher").toBool())
+        connect(&fileSystemWatch, &QFileSystemWatcher::fileChanged, this, &MainWindow::refreshDb, Qt::UniqueConnection);
+    else {
+        disconnect(&fileSystemWatch, &QFileSystemWatcher::fileChanged, nullptr, nullptr);
+        if (!fileSystemWatch.files().isEmpty())
+            fileSystemWatch.removePaths(fileSystemWatch.files());
+    }
 }
 
 void MainWindow::checkNewVersion(const bool automatic)
diff --git a/src/MainWindow.h b/src/MainWindow.h
@@ -6,7 +6,9 @@
 
 #include <memory>
 #include <vector>
+
 #include <QMainWindow>
+#include <QFileSystemWatcher>
 
 struct BrowseDataTableSettings;
 class DbStructureModel;
@@ -121,6 +123,8 @@ friend TableBrowserDock;
     QString currentProjectFilename;
     bool isProjectModified;
 
+    QFileSystemWatcher fileSystemWatch;
+
     void init();
     void clearCompleterModelsFields();
 
@@ -176,6 +180,7 @@ private slots:
     void fileNewInMemoryDatabase(bool open_create_dialog = true);
     // Refresh visible table browsers. When all is true, refresh all browsers.
     void refreshTableBrowsers(bool all = false);
+    void refreshDb();
     bool fileClose();
     bool fileSaveAs();
     void createTable();
diff --git a/src/PreferencesDialog.cpp b/src/PreferencesDialog.cpp
@@ -99,6 +99,7 @@ void PreferencesDialog::loadSettings()
     }
 
     ui->spinStructureFontSize->setValue(Settings::getValue("db", "fontsize").toInt());
+    ui->watcherCheckBox->setChecked(Settings::getValue("db", "watcher").toBool());
 
     // Gracefully handle the preferred Data Browser font not being available
     int matchingFont = ui->comboDataBrowserFont->findText(Settings::getValue("databrowser", "font").toString(), Qt::MatchExactly);
@@ -197,6 +198,7 @@ void PreferencesDialog::saveSettings(bool accept)
     Settings::setValue("db", "defaultsqltext", ui->editDatabaseDefaultSqlText->text());
     Settings::setValue("db", "defaultfieldtype", ui->defaultFieldTypeComboBox->currentIndex());
     Settings::setValue("db", "fontsize", ui->spinStructureFontSize->value());
+    Settings::setValue("db", "watcher", ui->watcherCheckBox->isChecked());
 
     Settings::setValue("checkversion", "enabled", ui->checkUpdates->isChecked());
 
diff --git a/src/PreferencesDialog.ui b/src/PreferencesDialog.ui
@@ -739,6 +739,29 @@ in new project file</string>
          <item row="5" column="1">
           <widget class="QSpinBox" name="spinStructureFontSize"/>
          </item>
+         <item row="6" column="0">
+          <widget class="QLabel" name="label_5">
+           <property name="toolTip">
+            <string>When the database is open in readonly mode, watch the database file and refresh when it is updated.</string>
+           </property>
+           <property name="text">
+            <string>&amp;When readonly, refresh on changed file</string>
+           </property>
+           <property name="buddy">
+            <cstring>watcherCheckBox</cstring>
+           </property>
+          </widget>
+         </item>
+       <item row="6" column="1">
+        <widget class="QCheckBox" name="watcherCheckBox">
+         <property name="text">
+          <string>enabled</string>
+         </property>
+         <property name="checked">
+          <bool>true</bool>
+         </property>
+        </widget>
+       </item>
         </layout>
        </item>
        <item>
diff --git a/src/Settings.cpp b/src/Settings.cpp
@@ -159,6 +159,10 @@ QVariant Settings::getDefaultValue(const std::string& group, const std::string&
     if(group == "db" && name == "fontsize")
         return 10;
 
+    // db/watcher?
+    if(group == "db" && name == "watcher")
+        return false;
+
     // exportcsv/firstrowheader?
     if(group == "exportcsv" && name == "firstrowheader")
         return true;
