backups: allow only one of "block device" and "VM"

Block device can be pointed only when source VM is "dom0".

qubesmanager/backup.py

@@ -91,6 +91,10 @@ class BackupVMsWindow(Ui_Backup, QWizard):
         self.connect(self.dev_combobox, SIGNAL("activated(int)"), self.dev_combobox_activated)
         self.connect(self, SIGNAL("backup_progress(int)"), self.progress_bar.setValue)
         self.dir_line_edit.connect(self.dir_line_edit, SIGNAL("textChanged(QString)"), self.backup_location_changed)
+        self.connect(self.dev_combobox, SIGNAL("activated(int)"),
+                self.update_device_appvm_enabled)
+        self.connect(self.appvm_combobox, SIGNAL("activated(int)"),
+                self.update_device_appvm_enabled)
 
         self.select_vms_page.isComplete = self.has_selected_vms
         self.select_dir_page.isComplete = self.has_selected_dir_and_pass
@@ -235,6 +239,9 @@ class BackupVMsWindow(Ui_Backup, QWizard):
     def dev_combobox_activated(self, idx):
         dev_combobox_activated(self, idx)
 
+    def update_device_appvm_enabled(self, idx):
+        update_device_appvm_enabled(self, idx)
+
     @pyqtSlot(name='on_select_path_button_clicked')
     def select_path_button_clicked(self):
         select_path_button_clicked(self)

qubesmanager/backup_utils.py

@@ -114,6 +114,10 @@ def enable_dir_line_edit(dialog, boolean):
     dialog.dir_line_edit.setEnabled(boolean)
     dialog.select_path_button.setEnabled(boolean)
 
+def update_device_appvm_enabled(dialog, idx):
+    # Only one of those can be used
+    dialog.dev_combobox.setEnabled(dialog.appvm_combobox.currentIndex() == 0)
+    dialog.appvm_combobox.setEnabled(dialog.dev_combobox.currentIndex() == 0)
 
 def dev_combobox_activated(dialog, idx):
     if idx == dialog.prev_dev_idx:    #nothing has changed

qubesmanager/restore.py

@@ -84,6 +84,10 @@ class RestoreVMsWindow(Ui_Restore, QWizard):
         self.connect(self, SIGNAL("restore_progress(QString)"), self.commit_text_edit.append)
         self.connect(self, SIGNAL("backup_progress(int)"), self.progress_bar.setValue)
         self.dir_line_edit.connect(self.dir_line_edit, SIGNAL("textChanged(QString)"), self.backup_location_changed)
+        self.connect(self.dev_combobox, SIGNAL("activated(int)"),
+                self.update_device_appvm_enabled)
+        self.connect(self.appvm_combobox, SIGNAL("activated(int)"),
+                self.update_device_appvm_enabled)
 
         self.select_dir_page.isComplete = self.has_selected_dir
         self.select_vms_page.isComplete = self.has_selected_vms
@@ -100,6 +104,9 @@ class RestoreVMsWindow(Ui_Restore, QWizard):
     def dev_combobox_activated(self, idx):
         dev_combobox_activated(self, idx)
 
+    def update_device_appvm_enabled(self, idx):
+        update_device_appvm_enabled(self, idx)
+
     @pyqtSlot(name='on_select_path_button_clicked')
     def select_path_button_clicked(self):
         select_path_button_clicked(self, True)