Handle randr screen change events.

bar.c

@@ -44,6 +44,7 @@ typedef struct screen_t {
 } screen_t;
 
 static xcb_connection_t *c;
+static xcb_screen_t     *scr;
 static xcb_window_t     win;
 static xcb_drawable_t   canvas;
 static xcb_gcontext_t   draw_gc;
@@ -488,14 +489,58 @@ get_randr_outputs(xcb_window_t w, screen_t **spp)
     return cnt;
 }
 
+int
+screen_adjust (screen_t *s, int num, screen_t **spp)
+{
+    int i, cnt, right_bar_offset;
+    screen_t *t;
+
+    /* Add BAR_OFFSET to the last screen */
+    right_bar_offset = scr->width_in_pixels - bar_width - BAR_OFFSET;
+
+    for (cnt = num, i = num-1; i >= 0; i--) {
+        if (right_bar_offset > 0) {
+            if (right_bar_offset >= s[i].width) {
+                /* Remove the screen */
+                cnt--;
+                right_bar_offset -= s[i].width;
+            } else {
+                s[i].width -= right_bar_offset;
+                right_bar_offset = 0;
+            }
+        }
+
+        s[i].x -= BAR_OFFSET;
+        if (s[i].x < 0) {
+            /* First screen */
+            s[i].x = 0;
+            break;
+        }
+    }
+
+    /* Remove BAR_OFFSET from the first screen */
+    s[i].width -= BAR_OFFSET;
+
+    t = calloc(cnt, sizeof(screen_t));
+    if (t == NULL)
+        exit(1);
+
+    for (i = 0; i < cnt; i++) {
+        t[i].x = s[i].x;
+        t[i].width = s[i].width;
+    }
+
+    *spp = t;
+
+    return cnt;
+}
 void
 init (void)
 {
-    xcb_screen_t *scr;
     xcb_window_t root;
-    screen_t *temp;
+    screen_t *stemp;
+    int snum;
     int y;
-    int right_bar_offset;
     xcb_generic_error_t *err;
     const xcb_query_extension_reply_t *ext_reply;
 
@@ -519,46 +564,18 @@ init (void)
         exit (1);
 
     /* Generate a list of screens */
-    num_screens = 0;
+    snum = 0;
     if ((ext_reply = xcb_get_extension_data(c, &xcb_randr_id)) && ext_reply->present) {
-        num_screens = get_randr_outputs(root, &screens);
+        snum = get_randr_outputs(root, &stemp);
-        randr_event = ext_reply->first_event;
+        if (snum)
+            randr_event = ext_reply->first_event;
     }
     else if ((ext_reply = xcb_get_extension_data(c, &xcb_xinerama_id)) && ext_reply->present)
-        num_screens = get_xinerama_outputs(root, &screens);
+        snum = get_xinerama_outputs(root, &stemp);
 
-    if (num_screens) {
+    if (snum) {
-        int i, num_saved = num_screens;
+        num_screens = screen_adjust(stemp, snum, &screens);
-        /* Add BAR_OFFSET to the last screen */
+        free(stemp);
-        right_bar_offset = scr->width_in_pixels - bar_width - BAR_OFFSET;
-        for (i = num_screens-1; i >= 0; i--) {
-            if (right_bar_offset > 0) {
-                if (right_bar_offset >= screens[i].width) {
-                    /* Remove the screen */
-                    num_screens--;
-                    right_bar_offset -= screens[i].width;
-                } else {
-                    screens[i].width -= right_bar_offset;
-                    right_bar_offset = 0;
-                }
-            }
-
-            screens[i].x -= BAR_OFFSET;
-            if (screens[i].x < 0) {
-                /* First screen */
-                screens[i].x = 0;
-                break;
-            }
-        }
-        /* Remove BAR_OFFSET from the first screen */
-        screens[i].width -= BAR_OFFSET;
-
-        /* Reallocate */
-        if (num_screens > num_saved) {
-            screens = realloc (screens, num_screens);
-            if (screens == NULL)
-                exit (1);
-        }
     } else {
         num_screens = 1;
         screens = calloc(1, sizeof(screen_t));
@@ -630,6 +647,18 @@ sighandle (int signal)
         exit (0);
 }
 
+void
+handle_randr_event (xcb_generic_event_t *ev)
+{
+    int num;
+    screen_t *s, *t = screens;
+
+    num = get_randr_outputs(scr->root, &s);
+    num_screens = screen_adjust(s, num, &screens);
+    free(s);
+    free(t);
+}
+
 int 
 main (int argc, char **argv)
 {
@@ -685,12 +714,14 @@ main (int argc, char **argv)
             }
             if (pollin[1].revents & POLLIN) { /* Xserver broadcasted an event */
                 while ((ev = xcb_poll_for_event (c))) {
-                    expose_ev = (xcb_expose_event_t *)ev;
+                    int type = ev->response_type & 0x7f;
 
-                    switch (ev->response_type & 0x7F) {
+                    if (randr_event > -1 && type == randr_event + XCB_RANDR_SCREEN_CHANGE_NOTIFY)
-                        case XCB_EXPOSE: 
+                        handle_randr_event(ev);
-                            if (expose_ev->count == 0) redraw = 1; 
+                    else if (type == XCB_EXPOSE) {
-                        break;
+                        expose_ev = (xcb_expose_event_t *)ev;
+                        if (expose_ev->count == 0)
+                            redraw = 1;
                     }
 
                     free (ev);