x11: xcb_aux_get_screen instead of two hand-rolled screen walks

win.c and xim.c each iterated the setup's roots to find the screen
xcb_connect had chosen; xcb-util, already linked through imdkit, has
xcb_aux_get_screen for that.

Dockerfile

@@ -23,6 +23,7 @@ RUN pacman -Syu --noconfirm --needed \
 	which \
 	xorg-server-xvfb \
 	xcb-imdkit \
+	xcb-util \
 	dbus \
 	&& pacman -Scc --noconfirm
 

Makefile

@@ -5,12 +5,12 @@ CFLAGS ?= -O2 -g
 WARN_CFLAGS = -Wall -Wextra
 IBUS_CFLAGS = $(shell $(PKG_CONFIG) --cflags dbus-1 xkbcommon)
 IBUS_LIBS = $(shell $(PKG_CONFIG) --libs dbus-1 xkbcommon)
-XIM_CFLAGS = $(shell $(PKG_CONFIG) --cflags xcb-imdkit xcb-xkb xkbcommon-x11)
+XIM_CFLAGS = $(shell $(PKG_CONFIG) --cflags xcb-imdkit xcb-aux xcb-xkb xkbcommon-x11)
-XIM_LIBS = $(shell $(PKG_CONFIG) --libs xcb-imdkit xcb-xkb xkbcommon-x11)
+XIM_LIBS = $(shell $(PKG_CONFIG) --libs xcb-imdkit xcb-aux xcb-xkb xkbcommon-x11)
 TEXT_CFLAGS = $(shell $(PKG_CONFIG) --cflags pangocairo cairo fontconfig)
 TEXT_LIBS = $(shell $(PKG_CONFIG) --libs pangocairo cairo fontconfig)
-POPUP_CFLAGS = $(shell $(PKG_CONFIG) --cflags xcb-randr)
+POPUP_CFLAGS = $(shell $(PKG_CONFIG) --cflags xcb-aux xcb-randr)
-POPUP_LIBS = $(shell $(PKG_CONFIG) --libs xcb-randr)
+POPUP_LIBS = $(shell $(PKG_CONFIG) --libs xcb-aux xcb-randr)
 PROJECT_CPPFLAGS =
 PROJECT_LDLIBS = -lthread -lbio -lxcb $(IBUS_LIBS) $(TEXT_LIBS) \
 	$(XIM_LIBS) $(POPUP_LIBS)

README.md

@@ -110,7 +110,7 @@ and cmp/diff, plus development files for:
 
 - Plan 9 port (`9c`, `9l`, `libthread`, and `libbio`);
 - D-Bus development files;
-- XCB, XCB RandR, XCB XKB, xcb-imdkit, xkbcommon, and xkbcommon-x11;
+- XCB, XCB RandR, XCB XKB, xcb-util, xcb-imdkit, xkbcommon, and xkbcommon-x11;
 - Pango, PangoCairo, Cairo, and Fontconfig;
 - GTK 3, plus libibus and Xlib for the live clients;
 - Xvfb for the X11 live tests;

tests/Makefile

@@ -18,8 +18,8 @@ IBUS_CLIENT_CFLAGS = $(shell $(PKG_CONFIG) --cflags ibus-1.0)
 IBUS_CLIENT_LIBS = $(shell $(PKG_CONFIG) --libs ibus-1.0)
 X11_CFLAGS = $(shell $(PKG_CONFIG) --cflags x11)
 X11_LIBS = $(shell $(PKG_CONFIG) --libs x11)
-XIM_CFLAGS = $(shell $(PKG_CONFIG) --cflags xcb-imdkit xcb-xkb xkbcommon-x11)
+XIM_CFLAGS = $(shell $(PKG_CONFIG) --cflags xcb-imdkit xcb-aux xcb-xkb xkbcommon-x11)
-XIM_LIBS = $(shell $(PKG_CONFIG) --libs xcb-imdkit xcb-xkb xkbcommon-x11)
+XIM_LIBS = $(shell $(PKG_CONFIG) --libs xcb-imdkit xcb-aux xcb-xkb xkbcommon-x11)
 UNIT_LDLIBS = -lthread -lbio $(TEXT_LIBS) $(IBUS_LIBS) $(XIM_LIBS)
 
 PROG = unit_test

win.c

@@ -1,4 +1,5 @@
 #include <xcb/xcb.h>
+#include <xcb/xcb_aux.h>
 #include <xcb/randr.h>
 #include "dat.h"
 #include "fn.h"
@@ -14,17 +15,6 @@ static xcb_atom_t workarea;
 static int hasrandr, imgh, imgw;
 static int shown, ptrx, ptry;	/* the popup, and where the pointer was as it came up */
 
-static xcb_screen_t*
-getscr(xcb_connection_t *c, int n)
-{
-	xcb_screen_iterator_t i;
-
-	for(i = xcb_setup_roots_iterator(xcb_get_setup(c)); i.rem; xcb_screen_next(&i))
-		if(n-- == 0)
-			return i.data;
-	return nil;
-}
-
 static xcb_visualtype_t*
 getvisual(xcb_screen_t *s)
 {
@@ -218,7 +208,7 @@ wininit(void)
 		wincleanup();
 		return 0;
 	}
-	scr = getscr(conn, n);
+	scr = xcb_aux_get_screen(conn, n);
 	if(scr == nil || !validformat(conn, scr)){
 		fprint(2, "strans: popup disabled: unsupported X root format\n");
 		wincleanup();

xim.c

@@ -5,6 +5,7 @@
 #include <locale.h>
 #include <poll.h>
 #include <xcb/xcb.h>
+#include <xcb/xcb_aux.h>
 #include <xcb/xkb.h>
 #include <xkbcommon/xkbcommon.h>
 #include <xkbcommon/xkbcommon-compose.h>
@@ -132,18 +133,6 @@ kwatch(void)
 		events, parts, parts, nil);
 }
 
-static xcb_screen_t*
-getscreen(int scr)
-{
-	xcb_screen_iterator_t iter;
-
-	iter = xcb_setup_roots_iterator(xcb_get_setup(conn));
-	for(; iter.rem; scr--, xcb_screen_next(&iter))
-		if(scr == 0)
-			return iter.data;
-	return nil;
-}
-
 static int
 translate(xcb_window_t win, int x, int y, Caret *caret)
 {
@@ -550,7 +539,7 @@ ximinit(void)
 		ximlog("cannot connect to X server");
 		return -1;
 	}
-	screen = getscreen(scr);
+	screen = xcb_aux_get_screen(conn, scr);
 	if(screen == nil){
 		ximlog("cannot find X screen");
 		return -1;