Improving native Windows file dialog in Rambetter-temp-fixes branch some

more.  This adds new code and improves code committed in revision 351.

- Calling GetOpenFileName() and GetSaveFileName() from a new thread, thus
allowing the main thread to continue refreshing GtkRadiant while the native
Windows file dialog is open.  Prevents the ugly "hall of mirrors" effect.
A similar approach is used in the open source Inkscape, so I'm not doing
anything too dangerous here.  However, this _is_ hacky in my opinion.

- Using memset() to zero out the memory of the OPENFILENAME structure.
This is safer than selectively setting fields on this structure.  We no
longer need to explicity set certain field to NULL now.

- "all files" filter now lowercase to be consistent with other code.

These changes have been tested on Windows XP and Windows 7.

THIS COMMIT SHOULD BE MERGED INTO TRUNK AT SOME POINT!!!


git-svn-id: svn://svn.icculus.org/gtkradiant/GtkRadiant/branches/Rambetter-temp-fixes@352 8a3a26a2-13c4-0310-b231-cf6edde360e5

radiant/gtkmisc.cpp

@@ -1203,11 +1203,45 @@ private:
 
 };
 
+#ifdef _WIN32
+
+static int in_file_dialog = 0;
+
+typedef struct {
+  gboolean open;
+  OPENFILENAME *ofn;
+  BOOL dlgRtnVal;
+  int done;
+} win32_native_file_dialog_comms_t;
+
+DWORD WINAPI win32_native_file_dialog_thread_func(LPVOID lpParam)
+{
+  win32_native_file_dialog_comms_t *fileDialogComms;
+  fileDialogComms = (win32_native_file_dialog_comms_t *) lpParam;
+  if (fileDialogComms->open) {
+    fileDialogComms->dlgRtnVal = GetOpenFileName(fileDialogComms->ofn);
+  }
+  else {
+    fileDialogComms->dlgRtnVal = GetSaveFileName(fileDialogComms->ofn);
+  }
+  fileDialogComms->done = -1; // No need to synchronize around lock.
+  return 0;
+}
+
+#endif
+
 /**
  * @param[in] baseSubDir should have a trailing slash if not @c NULL
  */
 const char* file_dialog (void *parent, gboolean open, const char* title, const char* path, const char* pattern, const char *baseSubDir)
 {
+
+#ifdef _WIN32
+  HANDLE fileDialogThreadHandle;
+  win32_native_file_dialog_comms_t fileDialogComms;
+  int dialogDone;
+#endif
+
   // Gtk dialog
   GtkWidget* file_sel;
   int loop = 1;
@@ -1240,27 +1274,29 @@ const char* file_dialog (void *parent, gboolean open, const char* title, const c
     Sys_Printf("Doing win32 file dialog...");
 #endif
     // do that the native way
-    /* Place the terminating null character in the szFile. */
-    szFile[0] = '\0';
 
+    if (in_file_dialog) return NULL; // Avoid recursive entry.
+    in_file_dialog = 1;
     /* Set the members of the OPENFILENAME structure. */
     // See http://msdn.microsoft.com/en-us/library/ms646839%28v=vs.85%29.aspx .
-    ofn.lStructSize = sizeof(OPENFILENAME);
+    memset(&ofn, 0, sizeof(ofn));
+    ofn.lStructSize = sizeof(ofn);
     ofn.hwndOwner = (HWND)GDK_WINDOW_HWND (g_pParentWnd->m_pWidget->window);
     ofn.nFilterIndex = 1; // The index is 1-based, not 0-based.  This basically says,
-                          // "select the first filter by default".
+                          // "select the first filter as default".
     if (pattern)
     {
       ofn.lpstrFilter = typelist.m_strWin32Filters;
     }
     else
     {
-      ofn.lpstrFilter = "All files\0*\0\0";
+      // TODO: Would be a bit cleaner if we could extract this string from
+      // GetFileTypeRegistry() instead of hardcoding it here.
+      ofn.lpstrFilter = "all files\0*.*\0"; // Second '\0' will be added to end of string.
     }
-    ofn.lpstrCustomFilter = NULL;
+    szFile[0] = '\0';
     ofn.lpstrFile = szFile;
     ofn.nMaxFile = sizeof(szFile);
-    ofn.lpstrFileTitle = NULL; // we don't need to get the name of the file
     if(path)
     {
       // szDirName: Radiant uses unix convention for paths internally
@@ -1272,21 +1308,42 @@ const char* file_dialog (void *parent, gboolean open, const char* title, const c
       *w = '\0';
       ofn.lpstrInitialDir = szDirName;
     }
-    else ofn.lpstrInitialDir = NULL;
     ofn.lpstrTitle = title;
     ofn.Flags = OFN_PATHMUSTEXIST | OFN_FILEMUSTEXIST | OFN_HIDEREADONLY;
 
-    /* Display the Open dialog box. */
-    // it's open or close depending on 'open' parameter
-    if (open)
-    {
-      if (!GetOpenFileName(&ofn))
-        return NULL;	// canceled
+    memset(&fileDialogComms, 0, sizeof(fileDialogComms));
+    fileDialogComms.open = open;
+    fileDialogComms.ofn = &ofn;
+
+    fileDialogThreadHandle =
+      CreateThread(NULL, // lpThreadAttributes
+                   0, // dwStackSize, default stack size
+                   win32_native_file_dialog_thread_func, // lpStartAddress, funcion to call
+                   &fileDialogComms, // lpParameter, argument to pass to function
+                   0, // dwCreationFlags
+                   NULL); // lpThreadId
+
+    dialogDone = 0;
+    while (1) {
+      // Avoid blocking indefinitely.  Another thread will set fileDialogComms->done to nonzero;
+      // we don't want to be in an indefinite blocked state when this happens.  We want to break
+      // out of here eventually.
+      while (gtk_events_pending()) {
+        gtk_main_iteration();
+      }
+      if (dialogDone) break;
+      if (fileDialogComms.done) dialogDone = 1; // One more loop of gtk_main_iteration() to get things in sync.
+      // Avoid tight infinte loop, add a small amount of sleep.
+      Sleep(10);
     }
-    else
-    {
-      if (!GetSaveFileName(&ofn))
-        return NULL;	// canceled
+    // Make absolutely sure that the thread is finished before we call CloseHandle().
+    WaitForSingleObject(fileDialogThreadHandle, INFINITE);
+    CloseHandle(fileDialogThreadHandle);
+
+    in_file_dialog = 0;
+    
+    if (!fileDialogComms.dlgRtnVal) {
+      return NULL; // Cancelled.
     }
 
     if(pattern != NULL)

radiant/preferences.cpp

@@ -2218,7 +2218,7 @@ void PrefsDlg::BuildDialog ()
 
 #ifdef _WIN32
   // win32 file dialog
-  check = gtk_check_button_new_with_label (_("Use win32 file load dialog"));
+  check = gtk_check_button_new_with_label (_("Use win32 file load dialog (hacky)"));
   gtk_widget_show (check);
   // gtk_container_add (GTK_CONTAINER (vbox), check);
   gtk_box_pack_start(GTK_BOX(vbox), check, FALSE, FALSE, 0);