Make electric borders work also during DND. Blame David and George

for getting me in Santa Claus mood.
FEATURE:86998

svn path=/trunk/kdebase/kwin/; revision=361725

atoms.cpp

@@ -9,8 +9,10 @@ You can Freely distribute this program under the GNU General Public
 License. See the file "COPYING" for the exact licensing terms.
 ******************************************************************/
 
+
 #include <qapplication.h>
 #include "atoms.h"
+#include <assert.h>
 
 namespace KWinInternal
 {
@@ -68,6 +70,13 @@ Atoms::Atoms()
     Atom fake;
     atoms[n] = &fake;
     names[n++] = (char *) "_DT_SM_WINDOW_INFO";
+    
+    atoms[n] = &xdnd_aware;
+    names[n++] = (char*) "XdndAware";
+    atoms[n] = &xdnd_position;
+    names[n++] = (char*) "XdndPosition";
+    
+    assert( n <= max );
 
     XInternAtoms( qt_xdisplay(), names, n, FALSE, atoms_return );
     for (int i = 0; i < n; i++ )

atoms.h

@@ -37,6 +37,8 @@ class Atoms
         Atom kde_net_wm_user_creation_time;
         Atom kde_system_tray_embedding;
         Atom net_wm_take_activity;
+        Atom xdnd_aware;
+        Atom xdnd_position;
     };
 
 

events.cpp

@@ -379,16 +379,8 @@ bool Workspace::workspaceEvent( XEvent * e )
                 QWhatsThis::leaveWhatsThisMode();
             }
 
-            if (electric_have_borders &&
-               (e->xcrossing.window == electric_top_border ||
-                e->xcrossing.window == electric_left_border ||
-                e->xcrossing.window == electric_bottom_border ||
-                e->xcrossing.window == electric_right_border))
-                {
-                // the user entered an electric border
-                electricBorder(e);
-                }
-            break;
+            if( electricBorder(e))
+                return true;
         case LeaveNotify:
             {
             if ( !QWhatsThis::inWhatsThisMode() )
@@ -446,6 +438,10 @@ bool Workspace::workspaceEvent( XEvent * e )
             // fall through
         case FocusOut:
             return true; // always eat these, they would tell Qt that KWin is the active app
+        case ClientMessage:
+            if( electricBorder( e ))
+                return true;
+            break;
         default:
             break;
         }

workspace.cpp

@@ -1910,6 +1910,16 @@ void Workspace::createBorderWindows()
                                   CopyFromParent,
                                   valuemask, &attributes);
     XMapWindow(qt_xdisplay(),  electric_right_border);
+    // Set XdndAware on the windows, so that DND enter events are received (#86998)
+    Atom version = 4; // XDND version
+    XChangeProperty( qt_xdisplay(), electric_top_border, atoms->xdnd_aware, XA_ATOM,
+        32, PropModeReplace, ( unsigned char* )&version, 1 );
+    XChangeProperty( qt_xdisplay(), electric_bottom_border, atoms->xdnd_aware, XA_ATOM,
+        32, PropModeReplace, ( unsigned char* )&version, 1 );
+    XChangeProperty( qt_xdisplay(), electric_left_border, atoms->xdnd_aware, XA_ATOM,
+        32, PropModeReplace, ( unsigned char* )&version, 1 );
+    XChangeProperty( qt_xdisplay(), electric_right_border, atoms->xdnd_aware, XA_ATOM,
+        32, PropModeReplace, ( unsigned char* )&version, 1 );
     }
 
 
@@ -2042,12 +2052,36 @@ void Workspace::clientMoved(const QPoint &pos, Time now)
 
 // this function is called when the user entered an electric border
 // with the mouse. It may switch to another virtual desktop
-void Workspace::electricBorder(XEvent *e)
+bool Workspace::electricBorder(XEvent *e)
     {
-    Time now = e->xcrossing.time;
-    QPoint p(e->xcrossing.x_root, e->xcrossing.y_root);
-
-    clientMoved(p, now);
+    if( !electric_have_borders )
+        return false;
+    if( e->type == EnterNotify )
+        {
+        if( e->xcrossing.window == electric_top_border ||
+            e->xcrossing.window == electric_left_border ||
+            e->xcrossing.window == electric_bottom_border ||
+            e->xcrossing.window == electric_right_border)
+            // the user entered an electric border
+            {
+            clientMoved( QPoint( e->xcrossing.x_root, e->xcrossing.y_root ), e->xcrossing.time );
+            return true;
+            }
+        }
+    if( e->type == ClientMessage )
+        {
+        if( e->xclient.message_type == atoms->xdnd_position
+            && ( e->xclient.window == electric_top_border
+                 || e->xclient.window == electric_bottom_border
+                 || e->xclient.window == electric_left_border
+                 || e->xclient.window == electric_right_border ))
+            {
+            updateXTime();
+            clientMoved( QPoint( e->xclient.data.l[2]>>16, e->xclient.data.l[2]&0xffff), qt_x_time );
+            return true;
+            }
+        }
+    return false;
     }
 
 // electric borders (input only windows) have to be always on the

workspace.h

@@ -415,7 +415,7 @@ class Workspace : public QObject, public KWinInterface, public KDecorationDefine
         void checkElectricBorders( bool force = false );
         void createBorderWindows();
         void destroyBorderWindows();
-        void electricBorder(XEvent * e);
+        bool electricBorder(XEvent * e);
         void raiseElectricBorders();
 
     // ------------------