[Win] Show error message if mainwin fails to load exe

Currently it will just die quietly which is no good for the user.
qgis · Jan 29, 2018 · 0be37ad · 0be37ad
1 parent cc9f7af
commit 0be37ad
Showing 1 changed file with 39 additions and 6 deletions.
diff --git a/src/app/mainwin.cpp b/src/app/mainwin.cpp
@@ -7,6 +7,18 @@
 #include <list>
 #include <memory>
 
+void showError( std::string message, std::string title )
+{
+  std::string newmessage = "Opps, looks like an error loading QGIS \n\n Details: \n\n" + message;
+  MessageBox(
+    NULL,
+    newmessage.c_str(),
+    title.c_str(),
+    MB_ICONERROR | MB_OK
+  );
+  std::cerr << message << std::endl;
+}
+
 std::string moduleExeBaseName( void )
 {
   DWORD l = MAX_PATH;
@@ -54,7 +66,8 @@ int CALLBACK WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdL
       }
       catch ( std::ifstream::failure e )
       {
-        std::cerr << "could read environment variable list " << basename + ".vars" << " [" << e.what() << "]" << std::endl;
+        std::string message = "Could not read environment variable list " + basename + ".vars" + " [" + e.what() + "]";
+        showError( message, "Error loading QGIS" );
         return EXIT_FAILURE;
       }
 
@@ -71,7 +84,8 @@ int CALLBACK WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdL
       }
       catch ( std::ifstream::failure e )
       {
-        std::cerr << "could not write environment file " << basename + ".env" << " [" << e.what() << "]" << std::endl;
+        std::string message = "Could not write environment file " + basename + ".env" + " [" + e.what() + "]";
+        showError( message, "Error loading QGIS" );
         return EXIT_FAILURE;
       }
     }
@@ -93,14 +107,16 @@ int CALLBACK WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdL
       {
         if ( _putenv( var.c_str() ) < 0 )
         {
-          std::cerr << "could not set environment variable:" << var << std::endl;
+          std::string message = "Could not set environment variable:" + var;
+          showError( message, "Error loading QGIS" );
           return EXIT_FAILURE;
         }
       }
     }
     catch ( std::ifstream::failure e )
     {
-      std::cerr << "could not read environment file " << basename + ".env" << " [" << e.what() << "]" << std::endl;
+      std::string message = "Could not read environment file " + basename + ".env" + " [" + e.what() + "]";
+      showError( message, "Error loading QGIS" );
       return EXIT_FAILURE;
     }
   }
@@ -114,14 +130,31 @@ int CALLBACK WinMain( HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdL
 
   if ( !hGetProcIDDLL )
   {
-    std::cerr << "Could not load the qgis_app.dll" << std::endl;
+    DWORD error = GetLastError();
+    LPTSTR errorText = NULL;
+
+    FormatMessage(
+      FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_IGNORE_INSERTS,
+      NULL,
+      error,
+      MAKELANGID( LANG_NEUTRAL, SUBLANG_DEFAULT ),
+      ( LPTSTR )&errorText,
+      0,
+      NULL );
+
+    std::string messsage = "Could not load qgis_app.dll \n Windows Error: " + std::string( errorText )
+            + "\n Help: \n\n Check " + basename + ".env for correct environment paths";
+    showError( messsage, "Error loading QGIS" );
+
+    LocalFree( errorText );
+    errorText = NULL;
     return EXIT_FAILURE;
   }
 
   int ( *realmain )( int, char *[] ) = ( int ( * )( int, char *[] ) ) GetProcAddress( hGetProcIDDLL, "main" );
   if ( !realmain )
   {
-    std::cerr << "could not locate main function in qgis_app.dll" << std::endl;
+    showError( "Could not locate main function in qgis_app.dll", "Error loading QGIS" );
     return EXIT_FAILURE;
   }