bug#1849 - Windows 7 Taskbar Support

* w32term.c (w32_initialize): Use GetModuleHandle for library that
is already loaded.
Set user model ID if supported (bug#1849).

* runemacs.c (set_user_model_id): New function.
(WinMain): Use it.

* emacsclient.c (w32_give_focus): Use GetModuleHandle for library
that is already loaded.
(w32_set_user_model_id): New function.
(main): Use it to associate emacsclient with emacs (bug#1849).

2 files changed, 36 insertions, 0 deletions

diff --git a/nt/ChangeLog b/nt/ChangeLog
index d8f9685587c..e4c95671aff 100644
--- a/nt/ChangeLog
+++ b/nt/ChangeLog
@@ -1,3 +1,8 @@
+2009-06-30  Jason Rumney  <jasonr@gnu.org>
+
+        * runemacs.c (set_user_model_id): New function.
+        (WinMain): Use it.
+
 2009-06-21  Chong Yidong  <cyd@stupidchicken.com>
 
         * Branch for 23.1.
diff --git a/nt/runemacs.c b/nt/runemacs.c
index 55a520f7bc7..aba1d439957 100644
--- a/nt/runemacs.c
+++ b/nt/runemacs.c
@@ -43,6 +43,8 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 #include <string.h>
 #include <malloc.h>
 
+static void set_user_model_id ();
+
 int WINAPI
 WinMain (HINSTANCE hSelf, HINSTANCE hPrev, LPSTR cmdline, int nShow)
 {
@@ -56,6 +58,8 @@ WinMain (HINSTANCE hSelf, HINSTANCE hPrev, LPSTR cmdline, int nShow)
   char *p;
   char modname[MAX_PATH];
 
+  set_user_model_id ();
+
   if (!GetModuleFileName (NULL, modname, MAX_PATH))
     goto error;
   if ((p = strrchr (modname, '\\')) == NULL)
@@ -170,5 +174,32 @@ error:
   return 1;
 }
 
+void set_user_model_id ()
+{
+  HMODULE shell;
+  HRESULT (WINAPI * set_user_model) (PCWSTR);
+
+  /* On Windows 7 and later, we need to set the user model ID
+     to associate emacsclient launched files with Emacs frames
+     in the UI.  */
+  shell = LoadLibrary ("shell32.dll");
+  if (shell)
+    {
+      set_user_model
+        = (void *) GetProcAddress (shell,
+                                   "SetCurrentProcessExplicitAppUserModelID");
+
+      /* If the function is defined, then we are running on Windows 7
+         or newer, and the UI uses this to group related windows
+         together.  Since emacs, runemacs, emacsclient are related, we
+         want them grouped even though the executables are different,
+         so we need to set a consistent ID between them.  */
+      if (set_user_model)
+        set_user_model (L"GNU.Emacs");
+
+      FreeLibrary (shell);
+    }
+}
+
 /* arch-tag: 7e02df73-4df7-4aa0-baea-99c6d047a384
    (do not change this comment) */