astrodatagui: improve error handling and connect to default db on start

astrodatagui/AstrodataGUI.py

@@ -3,7 +3,7 @@ import os
 
 from .db.StarsDB import StarDB
 
-DB_FILENAME = "stars.db"
+DEFAULT_DB = "stars.db"
 
 class AstrodataGUI(QtWidgets.QMainWindow):
     def __init__(self):
@@ -17,10 +17,12 @@ class AstrodataGUI(QtWidgets.QMainWindow):
 
     def loadDB(self):
         try:
-            self.starDB = StarDB.getInstance()
-        except:
+            self.starDB = StarDB.getInstance(DEFAULT_DB)
+        except Exception as e:
             self.showErrorMessage("DB Connection failed",
-                                  f"Could not connect to local database file {DB_FILENAME}")
+                                  f"Could not connect to local database file {DEFAULT_DB}\n\
+                                  {e}")
 
     def showErrorMessage(self, title: str, msg: str):
-        return
+        print(title)
+        print(msg)