Events.c: catch intermediate window position changes

nxagentHandleConfigureNotify() has an optimization that accumulates ConfigureNotify events from the queue to only perform the changes of the last ConfigureNotify event in the queue. But that code used to ignore position changes and only adapt the new window position if the last event happened to contain a position change. This change ensures the latest position change - if any - found in the queue will be applied after the accumulation. Fixes: ArticaProject/nx-libs#688 (second part)

Events.c: catch intermediate window position changes
f9bae755 · Ulrich Sibiller · Mike Gabriel · 00c1f05e · f9bae755
Commit f9bae755 authored May 04, 2018 by Ulrich Sibiller Committed by Mike Gabriel May 24, 2018
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Showing with 35 additions and 5 deletions

Events.c nx-X11/programs/Xserver/hw/nxagent/Events.c +35 -5

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--- a/nx-X11/programs/Xserver/hw/nxagent/Events.c
+++ b/nx-X11/programs/Xserver/hw/nxagent/Events.c
@@ -3341,13 +3341,26 @@ int nxagentHandleConfigureNotify(XEvent* X)
    {
      if (nxagentOption(AllScreens) == 0)
      {
+        /*
+         * - WITHOUT window manager any position change is relevant
+         * - WITH window manager only synthetic position changes send
+         *   by the window manager are relevant, see ICCCM Chapter 4,
+         *   "Configuring the Window"
+         */
+        Bool updatePos = (nxagentWMIsRunning == 0 || X -> xconfigure.send_event != 0);
+        int newX = X -> xconfigure.x;
+        int newY = X -> xconfigure.y;
+
        if (nxagentOption(DesktopResize) == 1)
        {
          if (nxagentOption(Width) != X -> xconfigure.width ||
                nxagentOption(Height) != X -> xconfigure.height ||
-                nxagentOption(X) != X -> xconfigure.x ||
-                nxagentOption(Y) != X -> xconfigure.y)
+                  (updatePos && (nxagentOption(X) != newX ||
+                                   nxagentOption(Y) != newY)))
          {
+            #ifdef DEBUG
+            int count = 0;
+            #endif
            Bool newEvents = False;

            doRandR = True;
@@ -3372,17 +3385,34 @@ int nxagentHandleConfigureNotify(XEvent* X)
              while (XCheckTypedWindowEvent(nxagentDisplay, nxagentDefaultWindows[pScreen -> myNum],
                                              ConfigureNotify, X))
              {
+                #ifdef DEBUG
+                count++;
+                #endif
+
+                if (nxagentWMIsRunning == 0 || X -> xconfigure.send_event)
+                {
+                  updatePos = True;
+                  newX = X -> xconfigure.x;
+                  newY = X -> xconfigure.y;
+                }
                newEvents = True;
              }

            } while (newEvents);
+
+            #ifdef DEBUG
+            fprintf(stderr, "%s: accumulated %d events\n", __func__, count);
+            #endif
          }
        }

-        if (nxagentWMIsRunning == 0 || X -> xconfigure.send_event)
+        if (updatePos)
        {
-          nxagentChangeOption(X, X -> xconfigure.x);
-          nxagentChangeOption(Y, X -> xconfigure.y);
+          #ifdef DEBUG
+          fprintf(stderr, "%s: Updating nxagent window position [%d,%d]\n", __func__, newX, newY);
+          #endif
+          nxagentChangeOption(X, newX);
+          nxagentChangeOption(Y, newY);
        }

        if (nxagentOption(Shadow) == 1 && nxagentOption(DesktopResize) == 1 &&