Small refactorings

app.c

@@ -22,7 +22,7 @@
 #include "app.h"
 
 void app_init(app_t *app) {
-	if (app == NULL)
+	if (!app)
 		return;
 
 	app->fileidx = 0;

events.c

@@ -30,7 +30,7 @@ void on_expose(app_t *app, XEvent *ev) {
 }
 
 void on_configurenotify(app_t *app, XEvent *ev) {
-	if (app == NULL || ev == NULL)
+	if (!app || !ev)
 		return;
 	
 	win_configure(&app->win, &ev->xconfigure);
@@ -40,7 +40,7 @@ void on_keypress(app_t *app, XEvent *ev) {
 	KeySym keysym;
 	XKeyEvent *kev;
 
-	if (app == NULL || ev == NULL)
+	if (!app || !ev)
 		return;
 	
 	kev = &ev->xkey;

window.c

@@ -27,6 +27,9 @@
 Display *dpy;
 int scr;
 int scrw, scrh;
+Visual *vis;
+Colormap cmap;
+int depth;
 GC gc;
 XColor bgcol;
 
@@ -35,7 +38,7 @@ void win_open(win_t *win) {
 	XSetWindowAttributes attr;
 	unsigned long mask;
 
-	if (win == NULL)
+	if (!win)
 		return;
 
 	if (!(dpy = XOpenDisplay(NULL)))
@@ -45,6 +48,10 @@ void win_open(win_t *win) {
 	scrw = DisplayWidth(dpy, scr);
 	scrh = DisplayHeight(dpy, scr);
 
+	vis = DefaultVisual(dpy, scr);
+	cmap = DefaultColormap(dpy, scr);
+	depth = DefaultDepth(dpy, scr);
+
 	if (!XAllocNamedColor(dpy, DefaultColormap(dpy, scr), BG_COLOR,
 			&bgcol, &bgcol))
 		FATAL("could not allocate color: %s", BG_COLOR);
@@ -61,9 +68,8 @@ void win_open(win_t *win) {
 	attr.save_under = False;
 	mask = CWBackingStore | CWBackPixel | CWSaveUnder;
 
-	win->xwin = XCreateWindow(dpy, RootWindow(dpy, scr),
-			win->x, win->y, win->w, win->h, 0, DefaultDepth(dpy, scr), InputOutput,
-			DefaultVisual(dpy, scr), mask, &attr);
+	win->xwin = XCreateWindow(dpy, RootWindow(dpy, scr), win->x, win->y,
+			win->w, win->h, 0, depth, InputOutput, vis, mask, &attr);
 	if (win->xwin == None)
 		FATAL("could not create window");
 	
@@ -84,7 +90,7 @@ void win_open(win_t *win) {
 }
 
 void win_close(win_t *win) {
-	if (win == NULL)
+	if (!win)
 		return;
 
 	XDestroyWindow(dpy, win->xwin);
@@ -95,7 +101,7 @@ void win_close(win_t *win) {
 int win_configure(win_t *win, XConfigureEvent *cev) {
 	int changed;
 
-	if (win == NULL)
+	if (!win)
 		return 0;
 	
 	changed = win->x != cev->x || win->y != cev->y ||