Handle window resize events properly

image.c

@@ -65,6 +65,9 @@ int img_load(img_t *img, const char *filename) {
 	imlib_context_set_image(im);
 
 	img->re = 0;
+	img->checkpan = 0;
+	img->zoomed = 0;
+
 	img->w = imlib_image_get_width();
 	img->h = imlib_image_get_height();
 
@@ -101,32 +104,32 @@ void img_render(img_t *img, win_t *win) {
 	if (!img || !win || !imlib_context_get_image())
 		return;
 
+	if ((!img->re || !img->zoomed) && SCALE_MODE != SCALE_ZOOM) {
+		/* set zoom level to fit image into window */
+		zw = (float) win->w / (float) img->w;
+		zh = (float) win->h / (float) img->h;
+		img->zoom = MIN(zw, zh);
+
+		if (img->zoom < zoom_min)
+			img->zoom = zoom_min;
+		else if (img->zoom > zoom_max)
+			img->zoom = zoom_max;
+
+		if (SCALE_MODE == SCALE_DOWN && img->zoom > 1.0)
+			img->zoom = 1.0;
+	}
+
 	if (!img->re) {
 		/* rendered for the first time */
 		img->re = 1;
-
-		/* set zoom level to fit image into window */
-		if (SCALE_MODE != SCALE_ZOOM) {
-			zw = (float) win->w / (float) img->w;
-			zh = (float) win->h / (float) img->h;
-			img->zoom = MIN(zw, zh);
-
-			if (img->zoom < zoom_min)
-				img->zoom = zoom_min;
-			else if (img->zoom > zoom_max)
-				img->zoom = zoom_max;
-
-			if (SCALE_MODE == SCALE_DOWN && img->zoom > 1.0)
-				img->zoom = 1.0;
-		}
-
 		/* center image in window */
 		img->x = (win->w - img->w * img->zoom) / 2;
 		img->y = (win->h - img->h * img->zoom) / 2;
-	} else if (img->cp) {
-		/* only useful after zooming */
+	}
+	
+	if (img->checkpan) {
 		img_check_pan(img, win);
-		img->cp = 0;
+		img->checkpan = 0;
 	}
 
 	/* calculate source and destination offsets */
@@ -174,7 +177,8 @@ int img_zoom(img_t *img, float z) {
 		img->x -= (img->w * z - img->w * img->zoom) / 2;
 		img->y -= (img->h * z - img->h * img->zoom) / 2;
 		img->zoom = z;
-		img->cp = 1;
+		img->checkpan = 1;
+		img->zoomed = 1;
 		return 1;
 	} else {
 		return 0;

image.h

@@ -37,7 +37,8 @@ typedef enum pandir_e {
 typedef struct img_s {
 	float zoom;
 	unsigned char re;
-	unsigned char cp;
+	unsigned char checkpan;
+	unsigned char zoomed;
 	int x;
 	int y;
 	int w;

main.c

@@ -18,6 +18,7 @@
 
 #include <stdlib.h>
 #include <stdio.h>
+#include <sys/select.h>
 
 #include <X11/Xlib.h>
 #include <X11/Xutil.h>
@@ -45,14 +46,34 @@ const char **filenames;
 unsigned int filecnt;
 unsigned int fileidx;
 
+unsigned char timeout;
+
 #define TITLE_LEN 256
 char win_title[TITLE_LEN];
 
 void run() {
+	int xfd;
+	fd_set fds;
+	struct timeval t;
 	XEvent ev;
 
-	while (!XNextEvent(win.env.dpy, &ev)) {
-		if (handler[ev.type])
+	timeout = 0;
+
+	while (1) {
+		if (timeout) {
+			t.tv_sec = 0;
+			t.tv_usec = 250;
+			xfd = ConnectionNumber(win.env.dpy);
+			FD_ZERO(&fds);
+			FD_SET(xfd, &fds);
+			
+			if (!XPending(win.env.dpy) && !select(xfd + 1, &fds, 0, 0, &t)) {
+				img_render(&img, &win);
+				timeout = 0;
+			}
+		}
+
+		if (!XNextEvent(win.env.dpy, &ev) && handler[ev.type])
 			handler[ev.type](&ev);
 	}
 }
@@ -175,6 +196,7 @@ void on_keypress(XEvent *ev) {
 	if (changed) {
 		img_render(&img, &win);
 		update_title();
+		timeout = 0;
 	}
 }
 
@@ -182,7 +204,10 @@ void on_configurenotify(XEvent *ev) {
 	if (!ev)
 		return;
 
-	win_configure(&win, &ev->xconfigure);
+	if (win_configure(&win, &ev->xconfigure)) {
+		img.checkpan = 1;
+		timeout = 1;
+	}
 }
 
 void update_title() {

window.c

@@ -102,19 +102,20 @@ void win_set_title(win_t *win, const char *title) {
 	XSetIconName(win->env.dpy, win->xwin, title);
 }
 
-int win_configure(win_t *win, XConfigureEvent *cev) {
+int win_configure(win_t *win, XConfigureEvent *c) {
 	int changed;
 
 	if (!win)
 		return 0;
 	
-	changed = win->x != cev->x || win->y != cev->y ||
-	          win->w != cev->width || win->h != cev->height;
-	win->x = cev->x;
-	win->y = cev->y;
-	win->w = cev->width;
-	win->h = cev->height;
-	win->bw = cev->border_width;
+	changed = win->w != c->width || win->h != c->height;
+
+	win->x = c->x;
+	win->y = c->y;
+	win->w = c->width;
+	win->h = c->height;
+	win->bw = c->border_width;
+
 	return changed;
 }