Misc: Code cleanup & debug code changes

- Merge @daBrado's focus event debugging code. Thanks!

- Use macro to reduce code redundancy in various functions.

- Move focus event validation from ev_focus_out() to a separate
  function.

- Add logic in ev_handle() to increase the chance of successful window
  name detection if compton is not reading window names normally (i.e.
  if there's no --shadow-exclude), when DEBUG_EVENTS is on.

src/compton.c

@@ -10,6 +10,12 @@
 
 #include "compton.h"
 
+#define MSTR_(s)        #s
+#define MSTR(s)         MSTR_(s)
+
+// Use #s here to prevent macro expansion
+#define CASESTRRET(s)   case s: return #s
+
 /**
  * Shared
  */
@@ -2651,99 +2657,49 @@ error(Display *dpy, XErrorEvent *ev) {
     exit(1);
   }
 
+#define CASESTRRET2(s)   case s: name = #s; break
+
   o = ev->error_code - xfixes_error;
   switch (o) {
-    case BadRegion:
+    CASESTRRET2(BadRegion);
-      name = "BadRegion";
-      break;
-    default:
-      break;
   }
 
   o = ev->error_code - damage_error;
   switch (o) {
-    case BadDamage:
+    CASESTRRET2(BadDamage);
-      name = "BadDamage";
-      break;
-    default:
-      break;
   }
 
   o = ev->error_code - render_error;
   switch (o) {
-    case BadPictFormat:
+    CASESTRRET2(BadPictFormat);
-      name = "BadPictFormat";
+    CASESTRRET2(BadPicture);
-      break;
+    CASESTRRET2(BadPictOp);
-    case BadPicture:
+    CASESTRRET2(BadGlyphSet);
-      name = "BadPicture";
+    CASESTRRET2(BadGlyph);
-      break;
-    case BadPictOp:
-      name = "BadPictOp";
-      break;
-    case BadGlyphSet:
-      name = "BadGlyphSet";
-      break;
-    case BadGlyph:
-      name = "BadGlyph";
-      break;
-    default:
-      break;
   }
 
   switch (ev->error_code) {
-    case BadAccess:
+    CASESTRRET2(BadAccess);
-      name = "BadAccess";
+    CASESTRRET2(BadAlloc);
-      break;
+    CASESTRRET2(BadAtom);
-    case BadAlloc:
+    CASESTRRET2(BadColor);
-      name = "BadAlloc";
+    CASESTRRET2(BadCursor);
-      break;
+    CASESTRRET2(BadDrawable);
-    case BadAtom:
+    CASESTRRET2(BadFont);
-      name = "BadAtom";
+    CASESTRRET2(BadGC);
-      break;
+    CASESTRRET2(BadIDChoice);
-    case BadColor:
+    CASESTRRET2(BadImplementation);
-      name = "BadColor";
+    CASESTRRET2(BadLength);
-      break;
+    CASESTRRET2(BadMatch);
-    case BadCursor:
+    CASESTRRET2(BadName);
-      name = "BadCursor";
+    CASESTRRET2(BadPixmap);
-      break;
+    CASESTRRET2(BadRequest);
-    case BadDrawable:
+    CASESTRRET2(BadValue);
-      name = "BadDrawable";
+    CASESTRRET2(BadWindow);
-      break;
-    case BadFont:
-      name = "BadFont";
-      break;
-    case BadGC:
-      name = "BadGC";
-      break;
-    case BadIDChoice:
-      name = "BadIDChoice";
-      break;
-    case BadImplementation:
-      name = "BadImplementation";
-      break;
-    case BadLength:
-      name = "BadLength";
-      break;
-    case BadMatch:
-      name = "BadMatch";
-      break;
-    case BadName:
-      name = "BadName";
-      break;
-    case BadPixmap:
-      name = "BadPixmap";
-      break;
-    case BadRequest:
-      name = "BadRequest";
-      break;
-    case BadValue:
-      name = "BadValue";
-      break;
-    case BadWindow:
-      name = "BadWindow";
-      break;
   }
 
+#undef CASESTRRET2
+
   print_timestamp();
   printf("error %d (%s) request %d minor %d serial %lu\n",
     ev->error_code, name, ev->request_code,
@@ -2888,34 +2844,22 @@ ev_serial(XEvent *ev) {
   return NextRequest(ev->xany.display);
 }
 
-static char *
+static const char *
 ev_name(XEvent *ev) {
   static char buf[128];
   switch (ev->type & 0x7f) {
-    case FocusIn:
+    CASESTRRET(FocusIn);
-      return "FocusIn";
+    CASESTRRET(FocusOut);
-    case FocusOut:
+    CASESTRRET(CreateNotify);
-      return "FocusOut";
+    CASESTRRET(ConfigureNotify);
-    case CreateNotify:
+    CASESTRRET(DestroyNotify);
-      return "CreateNotify";
+    CASESTRRET(MapNotify);
-    case ConfigureNotify:
+    CASESTRRET(UnmapNotify);
-      return "ConfigureNotify";
+    CASESTRRET(ReparentNotify);
-    case DestroyNotify:
+    CASESTRRET(CirculateNotify);
-      return "DestroyNotify";
+    CASESTRRET(Expose);
-    case MapNotify:
+    CASESTRRET(PropertyNotify);
-      return "Map";
+    CASESTRRET(ClientMessage);
-    case UnmapNotify:
-      return "Unmap";
-    case ReparentNotify:
-      return "Reparent";
-    case CirculateNotify:
-      return "Circulate";
-    case Expose:
-      return "Expose";
-    case PropertyNotify:
-      return "PropertyNotify";
-    case ClientMessage:
-      return "ClientMessage";
     default:
       if (ev->type == damage_event + XDamageNotify) {
         return "Damage";
@@ -2969,14 +2913,61 @@ ev_window(XEvent *ev) {
       return 0;
   }
 }
+
+static inline const char *
+ev_focus_mode_name(XFocusChangeEvent* ev) {
+  switch (ev->mode) {
+    CASESTRRET(NotifyNormal);
+    CASESTRRET(NotifyWhileGrabbed);
+    CASESTRRET(NotifyGrab);
+    CASESTRRET(NotifyUngrab);
+  }
+
+  return "Unknown";
+}
+
+static inline const char *
+ev_focus_detail_name(XFocusChangeEvent* ev) {
+  switch (ev->detail) {
+    CASESTRRET(NotifyAncestor);
+    CASESTRRET(NotifyVirtual);
+    CASESTRRET(NotifyInferior);
+    CASESTRRET(NotifyNonlinear);
+    CASESTRRET(NotifyNonlinearVirtual);
+    CASESTRRET(NotifyPointer);
+    CASESTRRET(NotifyPointerRoot);
+    CASESTRRET(NotifyDetailNone);
+  }
+
+  return "Unknown";
+}
+
+static inline void
+ev_focus_report(XFocusChangeEvent* ev) {
+  printf("  { mode: %s, detail: %s }\n", ev_focus_mode_name(ev),
+      ev_focus_detail_name(ev));
+}
+
 #endif
 
 /**
  * Events
  */
 
+inline static bool
+ev_focus_accept(XFocusChangeEvent *ev) {
+  return ev->mode == NotifyGrab
+    || (ev->mode == NotifyNormal
+        && (ev->detail == NotifyNonlinear
+          || ev->detail == NotifyNonlinearVirtual));
+}
+
 inline static void
 ev_focus_in(XFocusChangeEvent *ev) {
+#ifdef DEBUG_EVENTS
+  ev_focus_report(ev);
+#endif
+
   win *w = find_win(dpy, ev->window);
 
   // To deal with events sent from windows just destroyed
@@ -2987,14 +2978,12 @@ ev_focus_in(XFocusChangeEvent *ev) {
 
 inline static void
 ev_focus_out(XFocusChangeEvent *ev) {
-  if (ev->mode == NotifyGrab
+#ifdef DEBUG_EVENTS
-      || (ev->mode == NotifyNormal
+  ev_focus_report(ev);
-      && (ev->detail == NotifyNonlinear
+#endif
-      || ev->detail == NotifyNonlinearVirtual))) {
+
-    ;
+  if (!ev_focus_accept(ev))
-  } else {
     return;
-  }
 
   win *w = find_win(dpy, ev->window);
 
@@ -3214,7 +3203,9 @@ ev_handle(XEvent *ev) {
 
         if (w && w->name)
           window_name = w->name;
-        else
+        else if (!(w && w->client_win
+              && (to_free = (Bool) wid_get_name(dpy, w->client_win,
+                  &window_name))))
             to_free = (Bool) wid_get_name(dpy, wid, &window_name);
       }
     }

src/compton.h

@@ -1009,7 +1009,7 @@ win_get_class(Display *dpy, win *w);
 static int
 ev_serial(XEvent *ev);
 
-static char *
+static const char *
 ev_name(XEvent *ev);
 
 static Window