From 856ad4b230d6a5dc9abc21925eb69336c93a2446 Mon Sep 17 00:00:00 2001
From: Yuxuan Shui <yshuiv7@gmail.com>
Date: Thu, 7 Feb 2019 00:30:32 +0000
Subject: [PATCH] Wrap root window background prop check

It might be reused by the backends.

Depends on what the backend API ends up look like.

Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
---
 src/compton.c | 16 ++--------------
 src/render.c  | 16 +---------------
 src/x.c       |  2 +-
 src/x.h       |  2 +-
 4 files changed, 5 insertions(+), 31 deletions(-)

diff --git a/src/compton.c b/src/compton.c
index b000e16..41333e6 100644
--- a/src/compton.c
+++ b/src/compton.c
@@ -142,14 +142,6 @@ const char * const BACKEND_STRS[NUM_BKEND + 1] = {
   NULL
 };
 
-/// Names of root window properties that could point to a pixmap of
-/// background.
-const char *background_props_str[] = {
-  "_XROOTPMAP_ID",
-  "_XSETROOT_ID",
-  0,
-};
-
 // === Global variables ===
 
 /// Pointer to current session, as a global variable. Only used by
@@ -1647,14 +1639,10 @@ ev_property_notify(session_t *ps, xcb_property_notify_event_t *ev) {
     if (ps->o.track_focus && ps->o.use_ewmh_active_win
         && ps->atom_ewmh_active_win == ev->atom) {
       update_ewmh_active_win(ps);
-    }
-    else {
+    } else {
       // Destroy the root "image" if the wallpaper probably changed
-      for (int p = 0; background_props_str[p]; p++) {
-        if (ev->atom == get_atom(ps, background_props_str[p])) {
+      if (x_is_root_back_pixmap_atom(ps, ev->atom)) {
           root_damaged(ps);
-          break;
-        }
       }
     }
 
diff --git a/src/render.c b/src/render.c
index 09870a3..d8f8933 100644
--- a/src/render.c
+++ b/src/render.c
@@ -432,21 +432,7 @@ static bool get_root_tile(session_t *ps) {
 	ps->root_tile_fill = false;
 
 	bool fill = false;
-	xcb_pixmap_t pixmap = XCB_NONE;
-
-	// Get the values of background attributes
-	for (int p = 0; background_props_str[p]; p++) {
-		winprop_t prop =
-		    wid_get_prop(ps, ps->root, get_atom(ps, background_props_str[p]), 1L,
-		                 XCB_ATOM_PIXMAP, 32);
-		if (prop.nitems) {
-			pixmap = *prop.p32;
-			fill = false;
-			free_winprop(&prop);
-			break;
-		}
-		free_winprop(&prop);
-	}
+	xcb_pixmap_t pixmap = x_get_root_back_pixmap(ps);
 
 	// Make sure the pixmap we got is valid
 	if (pixmap && !x_validate_pixmap(ps->c, pixmap))
diff --git a/src/x.c b/src/x.c
index bdb48d6..fee9d0d 100644
--- a/src/x.c
+++ b/src/x.c
@@ -473,7 +473,7 @@ xcb_pixmap_t x_get_root_back_pixmap(session_t *ps) {
   return pixmap;
 }
 
-bool x_atom_is_background_prop(session_t *ps, xcb_atom_t atom) {
+bool x_is_root_back_pixmap_atom(session_t *ps, xcb_atom_t atom) {
   for (int p = 0; background_props_str[p]; p++) {
     xcb_atom_t prop_atom = get_atom(ps, background_props_str[p]);
     if (prop_atom == atom)
diff --git a/src/x.h b/src/x.h
index 8269e3f..eac48d1 100644
--- a/src/x.h
+++ b/src/x.h
@@ -164,6 +164,6 @@ xcb_pixmap_t x_get_root_back_pixmap(session_t *ps);
 
 /// Return true if the atom refers to a property name that is used for the
 /// root window background pixmap
-bool x_atom_is_background_prop(session_t *ps, xcb_atom_t atom);
+bool x_is_root_back_pixmap_atom(session_t *ps, xcb_atom_t atom);
 
 bool x_fence_sync(xcb_connection_t *, xcb_sync_fence_t);