[gtk+] GDK W32: Optimize clipboard handling a bit

[Руслан Ижбулатов <ruslanizhb src gnome org>]

commit b9b67e05e1f1f036322addafcd1479aebbc0fde5
Author: Руслан Ижбулатов <lrn1986 gmail com>
Date:   Sat Mar 19 09:49:56 2016 +0000

    GDK W32: Optimize clipboard handling a bit
    
    Delay as long as possible before calling OpenClipboard(),
    call CloseClipboard() as quickly as possible after that.
    Don't call OpenClipboard() when we don't need to (for example,
    we don't need to open clipboard to call GetClipboardOwner()).
    
    Also, print out actual W32 error code in some cases where it
    was not printed before.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=763907

 gdk/win32/gdkdisplay-win32.c   |   46 ++++++++++++++++++++++-----------------
 gdk/win32/gdkproperty-win32.c  |   13 ++++++-----
 gdk/win32/gdkselection-win32.c |    4 +-
 3 files changed, 35 insertions(+), 28 deletions(-)
---
diff --git a/gdk/win32/gdkdisplay-win32.c b/gdk/win32/gdkdisplay-win32.c
index c739e73..ce1c5bc 100644
--- a/gdk/win32/gdkdisplay-win32.c
+++ b/gdk/win32/gdkdisplay-win32.c
@@ -380,38 +380,46 @@ inner_clipboard_window_procedure (HWND   hwnd,
     case WM_CLIPBOARDUPDATE:
     case WM_DRAWCLIPBOARD:
       {
-        int success;
-        HWND hwndOwner;
-#ifdef G_ENABLE_DEBUG
-        UINT nFormat = 0;
-#endif
+        HWND hwnd_owner;
+        HWND hwnd_opener;
         GdkEvent *event;
         GdkWindow *owner;
 
-        success = OpenClipboard (hwnd);
-        if (!success)
-          {
-            g_warning ("Failed to OpenClipboard on window handle %p", hwnd);
-            return 0;
-          }
+        hwnd_owner = GetClipboardOwner ();
 
-        hwndOwner = GetClipboardOwner ();
-        owner = gdk_win32_window_lookup_for_display (_gdk_display, hwndOwner);
-        if (owner == NULL)
-          owner = gdk_win32_window_foreign_new_for_display (_gdk_display, hwndOwner);
+        if ((hwnd_owner == NULL) &&
+            (GetLastError () != ERROR_SUCCESS))
+            WIN32_API_FAILED ("GetClipboardOwner");
 
-        GDK_NOTE (DND, g_print (" drawclipboard owner: %p", hwndOwner));
+        hwnd_opener = GetOpenClipboardWindow ();
+
+        GDK_NOTE (DND, g_print (" drawclipboard owner: %p; opener %p ", hwnd_owner, hwnd_opener));
 
 #ifdef G_ENABLE_DEBUG
         if (_gdk_debug_flags & GDK_DEBUG_DND)
           {
-            while ((nFormat = EnumClipboardFormats (nFormat)) != 0)
-              g_print ("%s ", _gdk_win32_cf_to_string (nFormat));
+            if (OpenClipboard (hwnd))
+              {
+                UINT nFormat = 0;
+
+                while ((nFormat = EnumClipboardFormats (nFormat)) != 0)
+                  g_print ("%s ", _gdk_win32_cf_to_string (nFormat));
+
+                CloseClipboard ();
+              }
+            else
+              {
+                WIN32_API_FAILED ("OpenClipboard");
+              }
           }
 #endif
 
         GDK_NOTE (DND, g_print (" \n"));
 
+        owner = gdk_win32_window_lookup_for_display (_gdk_display, hwnd_owner);
+        if (owner == NULL)
+          owner = gdk_win32_window_foreign_new_for_display (_gdk_display, hwnd_owner);
+
         event = gdk_event_new (GDK_OWNER_CHANGE);
         event->owner_change.window = gdk_get_default_root_window ();
         event->owner_change.owner = owner;
@@ -421,8 +429,6 @@ inner_clipboard_window_procedure (HWND   hwnd,
         event->owner_change.selection_time = GDK_CURRENT_TIME;
         _gdk_win32_append_event (event);
 
-        CloseClipboard ();
-
         if (_hwnd_next_viewer != NULL)
           return SendMessage (_hwnd_next_viewer, message, wparam, lparam);
 
diff --git a/gdk/win32/gdkproperty-win32.c b/gdk/win32/gdkproperty-win32.c
index a393699..65850c3 100644
--- a/gdk/win32/gdkproperty-win32.c
+++ b/gdk/win32/gdkproperty-win32.c
@@ -194,12 +194,6 @@ _gdk_win32_window_change_property (GdkWindow    *window,
 
       if (type == _utf8_string)
        {
-         if (!OpenClipboard (GDK_WINDOW_HWND (window)))
-           {
-             WIN32_API_FAILED ("OpenClipboard");
-             return;
-           }
-
          wcptr = g_utf8_to_utf16 ((char *) data, nelements, NULL, &wclen, &err);
           if (err != NULL)
             {
@@ -208,6 +202,13 @@ _gdk_win32_window_change_property (GdkWindow    *window,
               return;
             }
 
+         if (!OpenClipboard (GDK_WINDOW_HWND (window)))
+           {
+             WIN32_API_FAILED ("OpenClipboard");
+             g_free (wcptr);
+             return;
+           }
+
          wclen++;              /* Terminating 0 */
          size = wclen * 2;
          for (i = 0; i < wclen; i++)
diff --git a/gdk/win32/gdkselection-win32.c b/gdk/win32/gdkselection-win32.c
index 6d7b7c7..131c0bf 100644
--- a/gdk/win32/gdkselection-win32.c
+++ b/gdk/win32/gdkselection-win32.c
@@ -492,6 +492,8 @@ _gdk_win32_display_convert_selection (GdkDisplay *display,
             }
         }
 
+      API_CALL (CloseClipboard, ());
+
       GDK_NOTE (DND, {
          int i;
 
@@ -514,8 +516,6 @@ _gdk_win32_display_convert_selection (GdkDisplay *display,
                                  ntargets * sizeof (GdkAtom));
       else
        property = GDK_NONE;
-
-      API_CALL (CloseClipboard, ());
     }
   else if (selection == GDK_SELECTION_CLIPBOARD && target == _utf8_string)
     {