Select the partition number if `--device` is passed with it

such as `sda1` or `hda2` will now select the specific partition

src/gui/mainwindow.cpp

@@ -1432,3 +1432,12 @@ void MainWindow::setCurrentDeviceByName(const QString& name)
                            xi18nc("@title:window", "Error While Importing Partition Table"));
     }
 }
+
+void MainWindow::setCurrentPartitionByName(const QString& partitionName)
+{
+    if (!pmWidget().setCurrentPartitionByName(partitionName)) {
+        KMessageBox::error(this,
+                           xi18nc("@info device should be inside of /dev", "Unrecognized partition \"%1\" ", partitionName),
+                           xi18nc("@title:window", "Error opening partition"));
+    }
+}

src/gui/mainwindow.h

@@ -48,6 +48,8 @@ public:
     // for instance `/dev/sda`
     void setCurrentDeviceByName(const QString& name);
 
+    void setCurrentPartitionByName(const QString& partitionNumber);
+
 Q_SIGNALS:
     void settingsChanged();
     void scanFinished();

src/gui/partitionmanagerwidget.cpp

@@ -282,6 +282,25 @@ void PartitionManagerWidget::on_m_TreePartitions_currentItemChanged(QTreeWidgetI
         partTableWidget().setActiveWidget(nullptr);
 }
 
+bool PartitionManagerWidget::setCurrentPartitionByName(const QString& name)
+{
+    auto rootNode = treePartitions().invisibleRootItem();
+    for (int i = 0; i < rootNode->childCount(); i++) {
+        auto driveNode = rootNode->child(i);
+        for (int e = 0; e < driveNode->childCount(); e++) {
+            auto partitionNode = driveNode->child(e);
+            const QString text = partitionNode->data(0, Qt::DisplayRole).toString();
+            if (text.endsWith(name)) {
+                partitionNode->setSelected(true);
+                treePartitions().setCurrentItem(partitionNode);
+                return true;
+            }
+        }
+    }
+
+    return false;
+}
+
 void PartitionManagerWidget::on_m_TreePartitions_itemDoubleClicked(QTreeWidgetItem* item, int)
 {
     if (item == treePartitions().topLevelItem(0)) {

src/gui/partitionmanagerwidget.h

@@ -94,6 +94,9 @@ public:
 
     void updatePartitions();
 
+    // here we expect the full "sda1" or "nvme1n1p1"
+    bool setCurrentPartitionByName(const QString& partitionName);
+
 protected:
     OperationStack& operationStack() {
         return *m_OperationStack;
@@ -125,6 +128,7 @@ protected:
         return *m_TreePartitions;
     }
 
+
     void onHeaderContextMenu(const QPoint& p);
 
 protected Q_SLOTS:

src/main.cpp

@@ -113,13 +113,18 @@ int Q_DECL_IMPORT main(int argc, char* argv[])
     if (!loadBackend())
         return 0;
 
+    // device is the selected device minus the partition number.
+    // we need all of them to select properly the things on screen.
     const QString selectedDevice = parser.value(deviceOption);
     auto [device, partitionNr] = parseDevice(selectedDevice);
 
     MainWindow* mainWindow = new MainWindow();
-    QObject::connect(mainWindow, &MainWindow::scanFinished, mainWindow, [mainWindow, selectedDevice] {
-        if (selectedDevice.length()) {
-            mainWindow->setCurrentDeviceByName(selectedDevice);
+    QObject::connect(mainWindow, &MainWindow::scanFinished, mainWindow, [mainWindow, device, selectedDevice, partitionNr] {
+        if (device.length()) {
+            mainWindow->setCurrentDeviceByName(device);
+            if (partitionNr.length()) {
+                mainWindow->setCurrentPartitionByName(selectedDevice);
+            }
         }
     });