Process _NET_WM_STATE_SKIP_TASKBAR hint in multiwindow mode.

Set WS_EX_TOOLWINDOW style to hide window from Alt-Tab switcher

Use ITaskBarList interface to ensure that the taskbar notices if the window
has changed it's style in a way which affects if the taskbar shows it or not

Signed-off-by: Jon TURNEY <jon.turney@dronecode.org.uk>

1 files changed, 33 insertions, 4 deletions

diff --git a/hw/xwin/winmultiwindowwm.c b/hw/xwin/winmultiwindowwm.c
index 159c27a7b..79c3fad44 100644
--- a/hw/xwin/winmultiwindowwm.c
+++ b/hw/xwin/winmultiwindowwm.c
@@ -867,6 +867,9 @@ winMultiWindowWMProc (void *pArg)
           {
             HWND zstyle = HWND_NOTOPMOST;
             UINT flags;
+            Bool onTaskbar;
+
+            /* XXX: probably should check for override-redirect and not do anything */
 
             pNode->msg.hwndWindow = getHwnd(pWMInfo, pNode->msg.iWindow);
 
@@ -878,6 +881,18 @@ winMultiWindowWMProc (void *pArg)
             flags = SWP_FRAMECHANGED | SWP_NOACTIVATE | SWP_NOMOVE | SWP_NOSIZE;
             if (zstyle == HWND_NOTOPMOST) flags |= SWP_NOZORDER | SWP_NOOWNERZORDER;
             SetWindowPos(pNode->msg.hwndWindow, NULL, 0, 0, 0, 0, flags);
+
+            /*
+              Use the WS_EX_TOOLWINDOW style to remove window from Alt-Tab window switcher
+
+              According to MSDN, this is supposed to remove the window from the taskbar as well,
+              if we SW_HIDE before changing the style followed by SW_SHOW afterwards.
+
+              But that doesn't seem to work reliably, so also use iTaskbarList interface to
+              tell the taskbar to show or hide this window.
+            */
+            onTaskbar = GetWindowLongPtr(pNode->msg.hwndWindow, GWL_EXSTYLE) & WS_EX_APPWINDOW;
+            wintaskbar(pNode->msg.hwndWindow, onTaskbar);
           }
 	  break;
 
@@ -1668,6 +1683,7 @@ winDeinitMultiWindowWM (void)
 #define HINT_NOMAXIMIZE (1L<<4)
 #define HINT_NOMINIMIZE (1L<<5)
 #define HINT_NOSYSMENU  (1L<<6)
+#define HINT_SKIPTASKBAR (1L<<7)
 /* These two are used on their own */
 #define HINT_MAX	(1L<<0)
 #define HINT_MIN	(1L<<1)
@@ -1676,12 +1692,13 @@ static void
 winApplyHints (Display *pDisplay, Window iWindow, HWND hWnd, HWND *zstyle)
 {
   static Atom		windowState, motif_wm_hints, windowType;
-  static Atom		hiddenState, fullscreenState, belowState, aboveState;
+  static Atom		hiddenState, fullscreenState, belowState, aboveState, skiptaskbarState;
   static Atom		dockWindow;
   static int		generation;
   Atom			type, *pAtom = NULL;
   int			format;
-  unsigned long		hint = 0, maxmin = 0, style, nitems = 0 , left = 0;
+  unsigned long		hint = 0, maxmin = 0, nitems = 0 , left = 0;
+  unsigned long         style, exStyle;
   MwmHints              *mwm_hint = NULL;
 
   if (!hWnd) return;
@@ -1697,6 +1714,7 @@ winApplyHints (Display *pDisplay, Window iWindow, HWND hWnd, HWND *zstyle)
       belowState = XInternAtom(pDisplay, "_NET_WM_STATE_BELOW", False);
       aboveState = XInternAtom(pDisplay, "_NET_WM_STATE_ABOVE", False);
       dockWindow = XInternAtom(pDisplay, "_NET_WM_WINDOW_TYPE_DOCK", False);
+      skiptaskbarState = XInternAtom(pDisplay, "_NET_WM_STATE_SKIP_TASKBAR", False);
   }
 
   if (XGetWindowProperty(pDisplay, iWindow, windowState, 0L,
@@ -1708,6 +1726,7 @@ winApplyHints (Display *pDisplay, Window iWindow, HWND hWnd, HWND *zstyle)
       unsigned long i;
       for (i = 0; i < nitems; i++)
 	{
+	  if (*pAtom == skiptaskbarState) hint |= HINT_SKIPTASKBAR;
 	  if (*pAtom == hiddenState) maxmin |= HINT_MIN;
 	  else if (*pAtom == fullscreenState) maxmin |= HINT_MAX;
 	  if (*pAtom == belowState) *zstyle = HWND_BOTTOM;
@@ -1843,9 +1862,9 @@ winApplyHints (Display *pDisplay, Window iWindow, HWND hWnd, HWND *zstyle)
 
   /* Now apply styles to window */
   style = GetWindowLongPtr(hWnd, GWL_STYLE) & ~WS_CAPTION & ~WS_SIZEBOX; /* Just in case */
-  if (!style) return;
+  if (!style) return; /* GetWindowLongPointer returns 0 on failure, we hope this isn't a valid style */
 
-  if (!hint) /* All on */
+  if (!(hint & ~HINT_SKIPTASKBAR)) /* All on */
     style = style | WS_CAPTION | WS_SIZEBOX;
   else if (hint & HINT_NOFRAME) /* All off */
     style = style & ~WS_CAPTION & ~WS_SIZEBOX;
@@ -1863,6 +1882,16 @@ winApplyHints (Display *pDisplay, Window iWindow, HWND hWnd, HWND *zstyle)
     style = style & ~WS_SYSMENU;
 
   SetWindowLongPtr (hWnd, GWL_STYLE, style);
+
+  /* now we have iTaskbar, use that as well */
+  exStyle = GetWindowLongPtr(hWnd, GWL_EXSTYLE);
+  if (hint & HINT_SKIPTASKBAR)
+    exStyle = (exStyle & ~WS_EX_APPWINDOW) | WS_EX_TOOLWINDOW;
+  else
+    exStyle = (exStyle & ~WS_EX_TOOLWINDOW) | WS_EX_APPWINDOW;
+  SetWindowLongPtr(hWnd, GWL_EXSTYLE, exStyle);
+
+  winDebug("winApplyHints: iWindow 0x%08x hints 0x%08x style 0x%08x exstyle 0x%08x\n", iWindow, hint, style, exStyle);
 }
 
 void