render: reload cursor theme when scale (may) have changed

main.c

@@ -128,6 +128,7 @@ output_scale(void *data, struct wl_output *wl_output, int32_t factor)
 {
     struct monitor *mon = data;
     mon->scale = factor;
+    render_reload_cursor_theme(mon->term);
     render_resize(mon->term, mon->term->width, mon->term->height);
 }
 
@@ -259,6 +260,7 @@ surface_enter(void *data, struct wl_surface *wl_surface,
             tll_push_back(term->wl.on_outputs, &it->item);
 
             /* Resize, since scale-to-use may have changed */
+            render_reload_cursor_theme(term);
             render_resize(term, term->width, term->height);
             return;
         }
@@ -280,6 +282,7 @@ surface_leave(void *data, struct wl_surface *wl_surface,
         tll_remove(term->wl.on_outputs, it);
 
         /* Resize, since scale-to-use may have changed */
+        render_reload_cursor_theme(term);
         render_resize(term, term->width, term->height);
         return;
     }
@@ -669,12 +672,6 @@ main(int argc, char *const *argv)
         term.wl.primary_selection_device, &primary_selection_device_listener, &term);
 
     /* Cursor */
-    term.wl.pointer.surface = wl_compositor_create_surface(term.wl.compositor);
-    if (term.wl.pointer.surface == NULL) {
-        LOG_ERR("failed to create cursor surface");
-        goto out;
-    }
-
     unsigned cursor_size = 24;
     const char *cursor_theme = getenv("XCURSOR_THEME");
 
@@ -687,20 +684,17 @@ main(int argc, char *const *argv)
         }
     }
 
+    /* Note: theme is (re)loaded on scale and output changes */
     LOG_INFO("cursor theme: %s, size: %u", cursor_theme, cursor_size);
+    term.wl.pointer.size = cursor_size;
+    term.wl.pointer.theme_name = cursor_theme != NULL ? strdup(cursor_theme) : NULL;
 
-    term.wl.pointer.theme = wl_cursor_theme_load(
+    term.wl.pointer.surface = wl_compositor_create_surface(term.wl.compositor);
-        cursor_theme, cursor_size * term.scale, term.wl.shm);
+    if (term.wl.pointer.surface == NULL) {
-    if (term.wl.pointer.theme == NULL) {
+        LOG_ERR("failed to create cursor surface");
-        LOG_ERR("failed to load cursor theme");
         goto out;
     }
 
-    term.wl.pointer.cursor = wl_cursor_theme_get_cursor(
-        term.wl.pointer.theme, "left_ptr");
-    assert(term.wl.pointer.cursor != NULL);
-    render_update_cursor_surface(&term);
-
     term.wl.surface = wl_compositor_create_surface(term.wl.compositor);
     if (term.wl.surface == NULL) {
         LOG_ERR("failed to create wayland surface");
@@ -999,6 +993,7 @@ out:
         xdg_toplevel_destroy(term.wl.xdg_toplevel);
     if (term.wl.xdg_surface != NULL)
         xdg_surface_destroy(term.wl.xdg_surface);
+    free(term.wl.pointer.theme_name);
     if (term.wl.pointer.theme != NULL)
         wl_cursor_theme_destroy(term.wl.pointer.theme);
     if (term.wl.pointer.pointer != NULL)

render.c

@@ -812,6 +812,48 @@ render_set_title(struct terminal *term, const char *title)
     xdg_toplevel_set_title(term->wl.xdg_toplevel, title);
 }
 
+bool
+render_reload_cursor_theme(struct terminal *term)
+{
+    if (term->wl.pointer.size == 0)
+        return true;
+
+    int scale = -1;
+    tll_foreach(term->wl.on_outputs, it) {
+        if (it->item->scale > scale)
+            scale = it->item->scale;
+    }
+
+    if (scale == -1) {
+        /* Haven't 'entered' an output yet? */
+        LOG_WARN("unknown scale, using '1'");
+        scale = 1;
+    }
+
+    if (term->wl.pointer.theme != NULL) {
+        wl_cursor_theme_destroy(term->wl.pointer.theme);
+        term->wl.pointer.theme = NULL;
+        term->wl.pointer.cursor = NULL;
+    }
+
+    LOG_DBG("reloading cursor theme: %s@%d",
+            term->wl.pointer.theme_name, term->wl.pointer.size);
+
+    term->wl.pointer.theme = wl_cursor_theme_load(
+        term->wl.pointer.theme_name, term->wl.pointer.size * scale, term->wl.shm);
+    if (term->wl.pointer.theme == NULL) {
+        LOG_ERR("failed to load cursor theme");
+        return false;
+    }
+
+    term->wl.pointer.cursor = wl_cursor_theme_get_cursor(
+        term->wl.pointer.theme, "left_ptr");
+    assert(term->wl.pointer.cursor != NULL);
+    render_update_cursor_surface(term);
+
+    return true;
+}
+
 void
 render_update_cursor_surface(struct terminal *term)
 {

render.h

@@ -8,9 +8,11 @@ struct font *attrs_to_font(
 void grid_render(struct terminal *term);
 void render_resize(struct terminal *term, int width, int height);
 void render_set_title(struct terminal *term, const char *title);
-void render_update_cursor_surface(struct terminal *term);
 void render_refresh(struct terminal *term);
 
+bool render_reload_cursor_theme(struct terminal *term);
+void render_update_cursor_surface(struct terminal *term);
+
 struct render_worker_context {
     int my_id;
     struct terminal *term;

terminal.h

@@ -57,6 +57,8 @@ struct wayland {
         struct wl_surface *surface;
         struct wl_cursor_theme *theme;
         struct wl_cursor *cursor;
+        int size;
+        char *theme_name;
     } pointer;
     struct xdg_wm_base *shell;
     struct xdg_surface *xdg_surface;