lstopo/x11: fix autoresizing when window is maximized

If the window is maximized, pressing + or - to change the scale
raises a ConfigureNotify event (as if the window had been resized)
that causes the scaling to go back to fit the window.

Detect whether the window is maximized during each ConfigureNotify
and don't ask for a scale update when we're maximized.

If the window is maximized in a single dimension, keep the current
behavior because zoom in/out will unmaximize it.

Thanks to Clement Foyer for the report.

Signed-off-by: Brice Goglin <Brice.Goglin@inria.fr>

utils/lstopo/lstopo-cairo.c

@@ -180,6 +180,7 @@ struct lstopo_x11_output {
   int needs_redraw;
   int needs_resize;
   int auto_resize;
+  int maximized;
 };
 
 static void
@@ -204,6 +205,33 @@ x11_destroy(struct lstopo_x11_output *disp)
   XDestroyWindow(disp->dpy, disp->win);
 }
 
+static int
+x11_is_maximized(struct lstopo_x11_output *disp)
+{
+  Atom type, state, maxed_h, maxed_v;
+  int format;
+  unsigned char *props;
+  unsigned long i, nr, bytesAfter;
+  int got_maxed_h = 0, got_maxed_v = 0;
+
+  state = XInternAtom(disp->dpy, "_NET_WM_STATE", True);
+  props = NULL;
+  if (Success == XGetWindowProperty(disp->dpy, disp->top, state, 0, (~0L), False, AnyPropertyType, &type, &format, &nr, &bytesAfter, &props)) {
+    maxed_h = XInternAtom(disp->dpy, "_NET_WM_STATE_MAXIMIZED_VERT", True);
+    maxed_v = XInternAtom(disp->dpy, "_NET_WM_STATE_MAXIMIZED_HORZ", True);
+    for(i=0; i<nr; i++) {
+      Atom prop = ((Atom*)(props))[i];
+      if (prop == maxed_h)
+        got_maxed_h = 1;
+      else if (prop == maxed_v)
+        got_maxed_v = 1;
+    }
+    XFree(props);
+  }
+  /* if the window is maximized in a single dimension, zoom in/out will unmaximize it */
+  return got_maxed_h && got_maxed_v;
+}
+
 /** Clip coordinates of the visible part. */
 static void
 move_x11(struct lstopo_x11_output *disp)
@@ -262,7 +290,7 @@ move_x11(struct lstopo_x11_output *disp)
       disp->y = disp->height - disp->screen_height;
   }
 
-  if (disp->needs_resize >= 1) {
+  if (disp->needs_resize >= 1 && !disp->maximized) {
     if (disp->auto_resize || disp->needs_resize >= 2) {
       disp->last_screen_width = disp->screen_width = disp->width;
       disp->last_screen_height = disp->screen_height = disp->height;
@@ -381,6 +409,7 @@ output_x11(struct lstopo_output *loutput, const char *dummy __hwloc_attribute_un
   disp->needs_redraw = 0;
   disp->needs_resize = 0;
   disp->auto_resize = 1;
+  disp->maximized = 0;
 
   x11_create(disp, loutput->width, loutput->height);
 
@@ -438,6 +467,7 @@ output_x11(struct lstopo_output *loutput, const char *dummy __hwloc_attribute_un
 	}
 	if (disp->x != lastx || disp->y != lasty)
 	  XMoveWindow(disp->dpy, disp->win, -disp->x, -disp->y);
+        disp->maximized = x11_is_maximized(disp);
 	break;
       }
       case ButtonPress: