Refactored the scan error message system which was too complicated, especially on cocoa. Replaced it with a simpler view.show_message(msg) call.

cocoa/inter/app.py

@@ -42,7 +42,7 @@ class PyDupeGuruBase(PyFairware):
         self.py.scanner.ignore_list.Clear()
     
     def doScan(self):
-        return self.py.start_scanning()
+        self.py.start_scanning()
     
     def exportToXHTMLwithColumns_(self, column_ids):
         return self.py.export_to_xhtml(column_ids)
@@ -197,4 +197,8 @@ class PyDupeGuruBase(PyFairware):
         NSUserDefaults.standardUserDefaults().setObject_forKey_(value, key_name)
     
     def show_extra_fairware_reminder(self):
-        self.cocoa.showExtraFairwareReminder()
+        self.cocoa.showExtraFairwareReminder()
+    
+    def show_message(self, msg):
+        self.cocoa.showMessage_(msg)
+    

cocoa/inter/app_pe.py

@@ -17,7 +17,7 @@ from hscommon import io
 from hscommon.util import remove_invalid_xml
 from hscommon.path import Path
 from hscommon.cocoa.objcmin import NSUserDefaults, NSURL
-from hscommon.trans import tr
+from hscommon.trans import tr, trmsg
 
 from core import directories
 from core_pe import _block_osx
@@ -189,11 +189,11 @@ class DupeGuruPE(DupeGuruBase):
         return ref.path
     
     def start_scanning(self):
-        result = DupeGuruBase.start_scanning(self)
         if self.directories.has_iphoto_path():
             try:
                 app('iPhoto')
             except ApplicationNotFoundError:
-                return 4
-        return result
+                self.view.show_message(trmsg("IPhotoAppNotFoundMsg"))
+                return
+        DupeGuruBase.start_scanning(self)