Implemented auto-hide functionality on Wayland

bar/bar.c

@@ -177,6 +177,18 @@ set_cursor(struct bar *bar, const char *cursor)
     b->backend.iface->set_cursor(bar, cursor);
 }
 
+static void
+set_visible(struct bar *bar, bool visible)
+{
+    struct private *b = bar->private;
+
+    if (b->layer != BAR_LAYER_HIDDEN)
+       return;
+
+    b->visible = visible;
+    bar->refresh(bar);
+}
+
 static const char *
 output_name(const struct bar *bar)
 {
@@ -446,6 +458,7 @@ bar_new(const struct bar_config *config)
     struct private *priv = calloc(1, sizeof(*priv));
     priv->monitor = config->monitor != NULL ? strdup(config->monitor) : NULL;
     priv->layer = config->layer;
+    priv->visible = false;
     priv->location = config->location;
     priv->height = config->height;
     priv->background = config->background;
@@ -488,6 +501,7 @@ bar_new(const struct bar_config *config)
     bar->destroy = &destroy;
     bar->refresh = &refresh;
     bar->set_cursor = &set_cursor;
+    bar->set_visible = &set_visible;
     bar->output_name = &output_name;
 
     for (size_t i = 0; i < priv->left.count; i++)

bar/bar.h

@@ -12,13 +12,14 @@ struct bar {
     void (*destroy)(struct bar *bar);
 
     void (*refresh)(const struct bar *bar);
+    void (*set_visible)(struct bar *bar, bool visible);
     void (*set_cursor)(struct bar *bar, const char *cursor);
 
     const char *(*output_name)(const struct bar *bar);
 };
 
 enum bar_location { BAR_TOP, BAR_BOTTOM };
-enum bar_layer { BAR_LAYER_OVERLAY, BAR_LAYER_TOP, BAR_LAYER_BOTTOM, BAR_LAYER_BACKGROUND };
+enum bar_layer { BAR_LAYER_OVERLAY, BAR_LAYER_TOP, BAR_LAYER_BOTTOM, BAR_LAYER_BACKGROUND, BAR_LAYER_HIDDEN };
 enum bar_backend { BAR_BACKEND_AUTO, BAR_BACKEND_XCB, BAR_BACKEND_WAYLAND };
 
 struct bar_config {

bar/private.h

@@ -8,6 +8,7 @@ struct private
     /* From bar_config */
     char *monitor;
     enum bar_layer layer;
+    bool visible;
     enum bar_location location;
     int height;
     int left_spacing, right_spacing;

bar/wayland.c

@@ -651,7 +651,7 @@ handle_global(void *data, struct wl_registry *registry, uint32_t name, const cha
     }
 
     else if (strcmp(interface, zwlr_layer_shell_v1_interface.name) == 0) {
-        const uint32_t required = 1;
+        const uint32_t required = 2;
         if (!verify_iface_version(interface, version, required))
             return;
 
@@ -773,6 +773,7 @@ create_surface(struct wayland_backend *backend)
         break;
 
     case BAR_LAYER_BOTTOM:
+    case BAR_LAYER_HIDDEN:
         layer = ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM;
         break;
 
@@ -1025,10 +1026,12 @@ update_size(struct wayland_backend *backend)
     bar->height_with_border = height;
 
     zwlr_layer_surface_v1_set_size(backend->layer_surface, 0, bar->height_with_border / scale);
-    zwlr_layer_surface_v1_set_exclusive_zone(
+    if (bar->layer != BAR_LAYER_HIDDEN) {
-        backend->layer_surface,
+        zwlr_layer_surface_v1_set_exclusive_zone(
-        (bar->height_with_border + (bar->location == BAR_TOP ? bar->border.bottom_margin : bar->border.top_margin))
+            backend->layer_surface,
+            (bar->height_with_border + (bar->location == BAR_TOP ? bar->border.bottom_margin : bar->border.top_margin))
             / scale);
+    }
 
     zwlr_layer_surface_v1_set_margin(backend->layer_surface, bar->border.top_margin / scale,
                                      bar->border.right_margin / scale, bar->border.bottom_margin / scale,
@@ -1243,8 +1246,14 @@ loop(struct bar *_bar, void (*expose)(const struct bar *bar),
             }
 
             LOG_DBG("coalesced %zu expose commands", count);
-            if (do_expose)
+            if (bar->layer == BAR_LAYER_HIDDEN) {
+              zwlr_layer_surface_v1_set_layer(
+                  backend->layer_surface,
+                  (bar->visible) ? ZWLR_LAYER_SHELL_V1_LAYER_OVERLAY : ZWLR_LAYER_SHELL_V1_LAYER_BOTTOM);
+            }
+            if (do_expose) {
                 expose(_bar);
+            }
         }
 
         if (fds[1].revents & POLLIN) {

config-verify.c

@@ -416,7 +416,7 @@ verify_bar_location(keychain_t *chain, const struct yml_node *node)
 static bool
 verify_bar_layer(keychain_t *chain, const struct yml_node *node)
 {
-    return conf_verify_enum(chain, node, (const char *[]){"overlay", "top", "bottom", "background"}, 4);
+    return conf_verify_enum(chain, node, (const char *[]){"overlay", "top", "bottom", "background", "hidden"}, 5);
 }
 
 bool

config.c

@@ -325,6 +325,8 @@ conf_to_bar(const struct yml_node *bar, enum bar_backend backend)
             conf.layer = BAR_LAYER_BOTTOM;
         else if (strcmp(tmp, "background") == 0)
             conf.layer = BAR_LAYER_BACKGROUND;
+        else if (strcmp(tmp, "hidden") == 0)
+            conf.layer = BAR_LAYER_HIDDEN;
         else
             assert(false);
     }

doc/yambar.5.scd

@@ -54,8 +54,9 @@ types that are frequently used:
 |  layer
 :  string
 :  no
-:  Layer to put bar on. One of _overlay_, _top_, _bottom_ or
+:  Layer to put bar on. One of _overlay_, _top_, _bottom_, _bottom_ or
-   _background_. Wayland only. Default: _bottom_.
+   _hidden_. Wayland only. Default: _bottom_. If set to _hidden_, will move
+   between _overlay_ and _bottom_ when receives respectively SIGUSR1 or SIGUSR2.
 |  left-spacing
 :  int
 :  no

main.c

@@ -27,6 +27,7 @@
 #include "version.h"
 
 static volatile sig_atomic_t aborted = 0;
+static volatile sig_atomic_t sigusr = 0;
 
 static void
 signal_handler(int signo)
@@ -34,6 +35,12 @@ signal_handler(int signo)
     aborted = signo;
 }
 
+static void
+sigusr_handler(int signo)
+{
+    sigusr = signo;
+}
+
 static char *
 get_config_path_user_config(void)
 {
@@ -295,12 +302,18 @@ main(int argc, char *const *argv)
     sigaction(SIGINT, &sa, NULL);
     sigaction(SIGTERM, &sa, NULL);
 
+    const struct sigaction sau = {.sa_handler = &sigusr_handler};
+    sigaction(SIGUSR1, &sau, NULL);
+    sigaction(SIGUSR2, &sau, NULL);
+
     /* Block SIGINT (this is under the assumption that threads inherit
      * the signal mask */
     sigset_t signal_mask;
     sigemptyset(&signal_mask);
     sigaddset(&signal_mask, SIGINT);
     sigaddset(&signal_mask, SIGTERM);
+    sigaddset(&signal_mask, SIGUSR1);
+    sigaddset(&signal_mask, SIGUSR2);
     pthread_sigmask(SIG_BLOCK, &signal_mask, NULL);
 
     int abort_fd = eventfd(0, EFD_CLOEXEC);
@@ -354,6 +367,10 @@ main(int argc, char *const *argv)
         struct pollfd fds[] = {{.fd = abort_fd, .events = POLLIN}};
         int r __attribute__((unused)) = poll(fds, sizeof(fds) / sizeof(fds[0]), -1);
 
+        if (sigusr) {
+            bar->set_visible(bar, (sigusr == SIGUSR1));
+            sigusr = 0;
+        }
         if (fds[0].revents & (POLLIN | POLLHUP)) {
             /*
              * Either the bar aborted (triggering the abort_fd), or user