Prompt to save changes in project when closing DB or application

The following changes set the project as modified in order to ask to save
changes in project file when closing DB or application:

The main database file and any attached database file.
* PRAGMA values
* Show Row Id option
* Encoding
* Unlock View Primary Key option
* Sort columns and sort directions
* Column widths
* Applied Filters
* Display Formats
* Hidden columns

See issue #1706

src/MainWindow.cpp

@@ -104,6 +104,7 @@ MainWindow::MainWindow(QWidget* parent)
       remoteDock(new RemoteDock(this)),
       findReplaceDialog(new FindReplaceDialog(this)),
       gotoValidator(new QIntValidator(0, 0, this)),
+      isProjectModified(false),
       execute_sql_worker(nullptr)
 {
     ui->setupUi(this);
@@ -535,7 +536,7 @@ void MainWindow::init()
     ui->dockRemote->setWindowTitle(ui->dockRemote->windowTitle().remove('&'));
 }
 
-bool MainWindow::fileOpen(const QString& fileName, bool dontAddToRecentFiles, bool readOnly)
+bool MainWindow::fileOpen(const QString& fileName, bool openFromProject, bool readOnly)
 {
     bool retval = false;
 
@@ -577,9 +578,10 @@ bool MainWindow::fileOpen(const QString& fileName, bool dontAddToRecentFiles, bo
                 statusEncryptionLabel->setVisible(db.encrypted());
                 statusReadOnlyLabel->setVisible(db.readOnly());
                 setCurrentFile(wFile);
-                currentProjectFilename.clear();
-                if(!dontAddToRecentFiles)
+                if(!openFromProject) {
+                    currentProjectFilename.clear();
                     addToRecentFilesMenu(wFile);
+                }
                 openSqlTab(true);
                 if(ui->mainTab->currentWidget() == ui->browser)
                     populateTable();
@@ -908,7 +910,7 @@ bool MainWindow::fileClose()
     }
 
     // Close the database but stop the closing process here if the user pressed the cancel button in there
-    if(!db.close())
+    if(!closeProject())
         return false;
 
     setWindowTitle(QApplication::applicationName());
@@ -973,6 +975,28 @@ bool MainWindow::closeFiles()
         // Ask for saving and comply with cancel answer.
         if(!askSaveSqlTab(i, ignoreUnattachedBuffers))
             return false;
+    return closeProject();
+}
+
+bool MainWindow::closeProject()
+{
+    if(!currentProjectFilename.isEmpty() && isProjectModified) {
+        QMessageBox::StandardButton reply = QMessageBox::question
+            (nullptr,
+             QApplication::applicationName(),
+             tr("Do you want to save the changes made to the project file %1?").
+             arg(QFileInfo(currentProjectFilename).fileName()),
+             QMessageBox::Save | QMessageBox::No | QMessageBox::Cancel);
+        switch(reply) {
+        case QMessageBox::Save:
+            saveProject();
+            break;
+        case QMessageBox::Cancel:
+            return false;
+        default:
+            break;
+        }
+    }
     return db.close();
 }
 
@@ -1749,7 +1773,7 @@ void MainWindow::importDatabaseFromSQL()
 
         // Create the new file and open it in the browser
         db.create(newDbFile);
-        db.close();
+        closeProject();
         fileOpen(newDbFile);
     }
 
@@ -2068,6 +2092,8 @@ void MainWindow::browseTableHeaderClicked(int logicalindex)
 
     // Reapply the view settings. This seems to be necessary as a workaround for newer Qt versions.
     applyBrowseTableSettings(settings);
+
+    isProjectModified = true;
 }
 
 void MainWindow::resizeEvent(QResizeEvent*)
@@ -2149,6 +2175,7 @@ void MainWindow::savePragmas()
     db.setPragma("user_version", ui->spinPragmaUserVersion->value(), pragmaValues.user_version);
     db.setPragma("wal_autocheckpoint", ui->spinPragmaWalAutoCheckpoint->value(), pragmaValues.wal_autocheckpoint);
     db.setPragma("case_sensitive_like", ui->checkboxPragmaCaseSensitiveLike->isChecked(), pragmaValues.case_sensitive_like);
+    isProjectModified = true;
 
     updatePragmaUi();
 }
@@ -2594,7 +2621,10 @@ void MainWindow::updateBrowseDataColumnWidth(int section, int /*old_size*/, int
 
     if (!selectedCols.contains(section))
     {
-        browseTableSettings[tableName].columnWidths[section] = new_size;
+        if (browseTableSettings[tableName].columnWidths[section] != new_size) {
+            isProjectModified = true;
+            browseTableSettings[tableName].columnWidths[section] = new_size;
+        }
     }
     else
     {
@@ -2602,7 +2632,10 @@ void MainWindow::updateBrowseDataColumnWidth(int section, int /*old_size*/, int
         for(int col : selectedCols)
         {
             ui->dataTable->setColumnWidth(col, new_size);
-            browseTableSettings[tableName].columnWidths[col] = new_size;
+            if (browseTableSettings[tableName].columnWidths[col] != new_size) {
+                isProjectModified = true;
+                browseTableSettings[tableName].columnWidths[col] = new_size;
+            }
         }
         ui->dataTable->blockSignals(false);
     }
@@ -2724,6 +2757,7 @@ bool MainWindow::loadProject(QString filename, bool readOnly)
         if(xml.name() != "sqlb_project")
             return false;
 
+        isProjectModified = false;
         addToRecentFilesMenu(filename);
 
         while(!xml.atEnd() && !xml.hasError())
@@ -2742,8 +2776,11 @@ bool MainWindow::loadProject(QString filename, bool readOnly)
 
                     // DB file
                     QString dbfilename = xml.attributes().value("path").toString();
-                    if(!QFile::exists(dbfilename))
+                    if(!QFile::exists(dbfilename)) {
                         dbfilename = QFileInfo(filename).absolutePath() + QDir::separator() + dbfilename;
+                        // New DB filename is pending to be saved
+                        isProjectModified = true;
+                    }
                     fileOpen(dbfilename, true, readOnly);
                     ui->dbTreeWidget->collapseAll();
 
@@ -3133,6 +3170,7 @@ QString MainWindow::saveProject(const QString& currentFilename)
         file.close();
 
         addToRecentFilesMenu(filename);
+        isProjectModified = false;
         QApplication::restoreOverrideCursor();
     }
     return filename;
@@ -3161,6 +3199,7 @@ void MainWindow::fileAttach()
 
     // Attach it
     db.attach(file);
+    isProjectModified = true;
 }
 
 void MainWindow::updateFilter(int column, const QString& value)
@@ -3168,9 +3207,12 @@ void MainWindow::updateFilter(int column, const QString& value)
     m_browseTableModel->updateFilter(column, value);
     BrowseDataTableSettings& settings = browseTableSettings[currentlyBrowsedTableName()];
     if(value.isEmpty())
-        settings.filterValues.remove(column);
+        isProjectModified = settings.filterValues.remove(column) > 0;
     else
-        settings.filterValues[column] = value;
+        if (settings.filterValues[column] != value) {
+            isProjectModified = true;
+            settings.filterValues[column] = value;
+        }
     setRecordsetLabel();
 
     // Reapply the view settings. This seems to be necessary as a workaround for newer Qt versions.
@@ -3193,6 +3235,7 @@ void MainWindow::clearAllCondFormats(int column)
     QVector<CondFormat> emptyCondFormatVector = QVector<CondFormat>();
     m_browseTableModel->setCondFormats(column, emptyCondFormatVector);
     browseTableSettings[currentlyBrowsedTableName()].condFormats[column].clear();
+    isProjectModified = true;
 }
 
 void MainWindow::editCondFormats(int column)
@@ -3203,6 +3246,7 @@ void MainWindow::editCondFormats(int column)
         QVector<CondFormat> condFormatVector = condFormatDialog.getCondFormats();
         m_browseTableModel->setCondFormats(column, condFormatVector);
         browseTableSettings[currentlyBrowsedTableName()].condFormats[column] = condFormatVector;
+        isProjectModified = true;
     }
 }
 
@@ -3429,6 +3473,7 @@ void MainWindow::editDataColumnDisplayFormat()
             browseTableSettings[current_table].displayFormats[field_number] = new_format;
         else
             browseTableSettings[current_table].displayFormats.remove(field_number);
+        isProjectModified = true;
 
         // Refresh view
         populateTable();
@@ -3457,7 +3502,10 @@ void MainWindow::showRowidColumn(bool show, bool skipFilters)
 
     // Save settings for this table
     sqlb::ObjectIdentifier current_table = currentlyBrowsedTableName();
-    browseTableSettings[current_table].showRowid = show;
+    if (browseTableSettings[current_table].showRowid != show) {
+        isProjectModified = true;
+        browseTableSettings[current_table].showRowid = show;
+    }
 
     // Update the filter row
     if(!skipFilters)
@@ -3517,6 +3565,7 @@ void MainWindow::browseDataSetTableEncoding(bool forAllTables)
             for(auto it=browseTableSettings.begin();it!=browseTableSettings.end();++it)
                 it.value().encoding = encoding;
         }
+        isProjectModified = true;
     }
 }
 
@@ -3595,6 +3644,7 @@ void MainWindow::unlockViewEditing(bool unlock, QString pk)
         settings.unlockViewPk = pk;
         // Reapply the view settings. This seems to be necessary as a workaround for newer Qt versions.
         applyBrowseTableSettings(settings);
+        isProjectModified = true;
     }
 }
 
@@ -3645,6 +3695,7 @@ void MainWindow::hideColumns(int column, bool hide)
 
     if(allHidden  && ui->dataTable->model()->columnCount() > 1)
         hideColumns(1, false);
+    isProjectModified = true;
 }
 
 void MainWindow::on_actionShowAllColumns_triggered()