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).

6 files changed, 113 insertions, 10 deletions

diff --git a/lib-src/ChangeLog b/lib-src/ChangeLog
index 590af7692ef..4969b93734d 100644
--- a/lib-src/ChangeLog
+++ b/lib-src/ChangeLog
@@ -1,3 +1,10 @@
+2009-06-30  Jason Rumney  <jasonr@gnu.org>
+
+        * 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).
+
 2009-06-29  Jim Meyering  <meyering@redhat.com>
 
         Remove useless if-before-free test.
diff --git a/lib-src/emacsclient.c b/lib-src/emacsclient.c
index a451c1b9ba4..5e6db54a902 100644
--- a/lib-src/emacsclient.c
+++ b/lib-src/emacsclient.c
@@ -392,6 +392,33 @@ w32_getenv (envvar)
   return NULL;
 }
 
+void
+w32_set_user_model_id ()
+{
+  HMODULE shell;
+  HRESULT (WINAPI * set_user_model) (PWCSTR);
+
+  /* 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);
+    }
+}
+
 int
 w32_window_app ()
 {
@@ -1415,22 +1442,23 @@ w32_find_emacs_process (hWnd, lParam)
 void
 w32_give_focus ()
 {
-  HMODULE hUser32;
+  HANDLE user32;
 
   /* It shouldn't happen when dealing with TCP sockets.  */
   if (!emacs_pid) return;
 
-  if (!(hUser32 = LoadLibrary ("user32.dll"))) return;
+  user32 = GetModuleHandle ("user32.dll");
+
+  if (!user32)
+    return;
 
   /* Modern Windows restrict which processes can set the foreground window.
      emacsclient can allow Emacs to grab the focus by calling the function
      AllowSetForegroundWindow.  Unfortunately, older Windows (W95, W98 and
      NT) lack this function, so we have to check its availability.  */
-  if ((set_fg = GetProcAddress (hUser32, "AllowSetForegroundWindow"))
-      && (get_wc = GetProcAddress (hUser32, "RealGetWindowClassA")))
+  if ((set_fg = GetProcAddress (user32, "AllowSetForegroundWindow"))
+      && (get_wc = GetProcAddress (user32, "RealGetWindowClassA")))
     EnumWindows (w32_find_emacs_process, (LPARAM) 0);
-
-  FreeLibrary (hUser32);
 }
 #endif
 
@@ -1501,6 +1529,12 @@ main (argc, argv)
   main_argv = argv;
   progname = argv[0];
 
+#ifdef WINDOWSNT
+  /* On Windows 7 and later, we need to explicitly associate emacsclient
+     with emacs so the UI behaves sensibly.  */
+  w32_set_user_model_id ();
+#endif
+
   /* Process options.  */
   decode_options (argc, argv);
 
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) */
diff --git a/src/ChangeLog b/src/ChangeLog
index dcf58c7f631..b06bf4fac8c 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,9 @@
+2009-06-30  Jason Rumney  <jasonr@gnu.org>
+
+        * w32term.c (w32_initialize): Use GetModuleHandle for library that
+        is already loaded.
+        Set user model ID if supported (bug#1849).
+
 2009-06-29  Jim Meyering  <meyering@redhat.com>
 
         Remove useless if-before-xfree test.
diff --git a/src/w32term.c b/src/w32term.c
index 209e86edc8b..c3cfc341169 100644
--- a/src/w32term.c
+++ b/src/w32term.c
@@ -138,7 +138,7 @@ typedef struct tagGLYPHSET
 #endif
 
 /* Dynamic linking to SetLayeredWindowAttribute (only since 2000).  */
-BOOL (PASCAL *pfnSetLayeredWindowAttributes) (HWND, COLORREF, BYTE, DWORD);
+BOOL (WINAPI *pfnSetLayeredWindowAttributes) (HWND, COLORREF, BYTE, DWORD);
 
 #ifndef LWA_ALPHA
 #define LWA_ALPHA 0x02
@@ -6340,6 +6340,9 @@ DWORD WINAPI w32_msg_worker (void * arg);
 static void
 w32_initialize ()
 {
+  HANDLE shell;
+  HRESULT (WINAPI * set_user_model) (PCWSTR);
+
   baud_rate = 19200;
 
   w32_system_caret_hwnd = NULL;
@@ -6347,6 +6350,25 @@ w32_initialize ()
   w32_system_caret_x = 0;
   w32_system_caret_y = 0;
 
+  /* 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 = GetModuleHandle ("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");
+    }
+
   /* Initialize w32_use_visible_system_caret based on whether a screen
      reader is in use.  */
   if (!SystemParametersInfo (SPI_GETSCREENREADER, 0,
@@ -6400,7 +6422,7 @@ w32_initialize ()
 
   /* Dynamically link to optional system components.  */
   {
-    HANDLE user_lib = LoadLibrary ("user32.dll");
+    HMODULE user_lib = GetModuleHandle ("user32.dll");
 
 #define LOAD_PROC(lib, fn) pfn##fn = (void *) GetProcAddress (lib, #fn)
 
@@ -6408,8 +6430,6 @@ w32_initialize ()
 
 #undef LOAD_PROC
 
-    FreeLibrary (user_lib);
-
     /* Ensure scrollbar handle is at least 5 pixels.  */
     vertical_scroll_bar_min_handle = 5;