Implement bindsym --release

This is a "simple" version of --release (same as i3) that only supports
a binding that contain one normal key. e.g.:

    bindsym --release $mod+x exec somthing-fun

I didn't bother implementing it for a combination like `$mod+x+z` since
it is a bit tricky to get right and also a bit weird to actually do on a
keyboard.

3 files changed, 88 insertions, 27 deletions

diff --git a/sway/commands.c b/sway/commands.c
index 4e5bc712..6a316596 100644
--- a/sway/commands.c
+++ b/sway/commands.c
@@ -163,9 +163,25 @@ static struct cmd_results *cmd_bindsym(int argc, char **argv) {
                 return cmd_results_new(CMD_FAILURE, "bindsym", "Can only be used in config file.");
         }
 
+
         struct sway_binding *binding = malloc(sizeof(struct sway_binding));
         binding->keys = create_list();
         binding->modifiers = 0;
+        binding->release = false;
+
+        // Handle --release
+        if (strcmp("--release", argv[0]) == 0) {
+                if (argc >= 3) {
+                        binding->release = true;
+                        argv++;
+                        argc--;
+                } else {
+                        return cmd_results_new(CMD_FAILURE, "bindsym",
+                                "Invalid bindsym command"
+                                "(expected more than 2 arguments, got %d)", argc);
+                }
+        }
+
         binding->command = join_args(argv + 1, argc - 1);
 
         list_t *split = split_string(argv[0], "+");
diff --git a/sway/handlers.c b/sway/handlers.c
index 470f3c95..e0acebea 100644
--- a/sway/handlers.c
+++ b/sway/handlers.c
@@ -336,6 +336,43 @@ static void handle_view_state_request(wlc_handle view, enum wlc_view_state_bit s
         return;
 }
 
+static bool handle_bindsym(struct sway_binding *binding) {
+        bool match = false;
+        int i;
+        for (i = 0; i < binding->keys->length; ++i) {
+                xkb_keysym_t *key = binding->keys->items[i];
+                if ((match = check_key(*key, 0)) == false) {
+                        break;
+                }
+        }
+
+        if (match) {
+                struct cmd_results *res = handle_command(binding->command);
+                if (res->status != CMD_SUCCESS) {
+                        sway_log(L_ERROR, "Command '%s' failed: %s", res->input, res->error);
+                }
+                free_cmd_results(res);
+                return true;
+        }
+
+        return false;
+}
+
+static bool handle_bindsym_release(struct sway_binding *binding) {
+        if (binding->keys->length == 1) {
+                xkb_keysym_t *key = binding->keys->items[0];
+                if (check_released_key(*key)) {
+                        struct cmd_results *res = handle_command(binding->command);
+                        if (res->status != CMD_SUCCESS) {
+                                sway_log(L_ERROR, "Command '%s' failed: %s", res->input, res->error);
+                        }
+                        free_cmd_results(res);
+                        return true;
+                }
+        }
+
+        return false;
+}
 
 static bool handle_key(wlc_handle view, uint32_t time, const struct wlc_modifiers *modifiers,
                 uint32_t key, enum wlc_key_state state) {
@@ -366,33 +403,6 @@ static bool handle_key(wlc_handle view, uint32_t time, const struct wlc_modifier
                 release_key(sym, key);
         }
 
-        for (i = 0; i < mode->bindings->length; ++i) {
-                struct sway_binding *binding = mode->bindings->items[i];
-
-                if ((modifiers->mods ^ binding->modifiers) == 0) {
-                        bool match = false;
-                        int j;
-                        for (j = 0; j < binding->keys->length; ++j) {
-                                xkb_keysym_t *key = binding->keys->items[j];
-                                if ((match = check_key(*key, 0)) == false) {
-                                        break;
-                                }
-                        }
-                        if (match) {
-                                if (state == WLC_KEY_STATE_PRESSED) {
-                                        struct cmd_results *res = handle_command(binding->command);
-                                        if (res->status != CMD_SUCCESS) {
-                                                sway_log(L_ERROR, "Command '%s' failed: %s", res->input, res->error);
-                                        }
-                                        free_cmd_results(res);
-                                        return EVENT_HANDLED;
-                                } else if (state == WLC_KEY_STATE_RELEASED) {
-                                        // TODO: --released
-                                }
-                        }
-                }
-        }
-
         // handle bar modifiers pressed/released
         uint32_t modifier;
         for (i = 0; i < config->active_bar_modifiers->length; ++i) {
@@ -409,6 +419,27 @@ static bool handle_key(wlc_handle view, uint32_t time, const struct wlc_modifier
         }
         // update modifiers state
         modifiers_state_update(modifiers->mods);
+
+        // handle bindings
+        for (i = 0; i < mode->bindings->length; ++i) {
+                struct sway_binding *binding = mode->bindings->items[i];
+                if ((modifiers->mods ^ binding->modifiers) == 0) {
+                        switch (state) {
+                        case WLC_KEY_STATE_PRESSED: {
+                                if (!binding->release && handle_bindsym(binding)) {
+                                        return EVENT_HANDLED;
+                                }
+                                break;
+                        }
+                        case WLC_KEY_STATE_RELEASED:
+                                if (binding->release && handle_bindsym_release(binding)) {
+                                        return EVENT_HANDLED;
+                                }
+                                break;
+                        }
+                }
+        }
+
         return EVENT_PASSTHROUGH;
 }
 
diff --git a/sway/input_state.c b/sway/input_state.c
index 2f40b6c2..86868083 100644
--- a/sway/input_state.c
+++ b/sway/input_state.c
@@ -22,6 +22,8 @@ struct key_state {
 
 static struct key_state key_state_array[KEY_STATE_MAX_LENGTH];
 
+static struct key_state last_released;
+
 static uint32_t modifiers_state;
 
 void input_init(void) {
@@ -31,6 +33,9 @@ void input_init(void) {
                 key_state_array[i] = none;
         }
 
+        struct key_state none = { 0, 0, 0 };
+        last_released = none;
+
         modifiers_state = 0;
 }
 
@@ -76,6 +81,12 @@ bool check_key(uint32_t key_sym, uint32_t key_code) {
         return find_key(key_sym, key_code, false) < KEY_STATE_MAX_LENGTH;
 }
 
+bool check_released_key(uint32_t key_sym) {
+        return (key_sym != 0
+                && (last_released.key_sym == key_sym
+                || last_released.alt_sym == key_sym));
+}
+
 void press_key(uint32_t key_sym, uint32_t key_code) {
         if (key_code == 0) {
                 return;
@@ -94,6 +105,9 @@ void press_key(uint32_t key_sym, uint32_t key_code) {
 void release_key(uint32_t key_sym, uint32_t key_code) {
         uint8_t index = find_key(key_sym, key_code, true);
         if (index < KEY_STATE_MAX_LENGTH) {
+                last_released.key_sym = key_state_array[index].key_sym;
+                last_released.alt_sym = key_state_array[index].alt_sym;
+                last_released.key_code = key_state_array[index].key_code;
                 struct key_state none = { 0, 0, 0 };
                 key_state_array[index] = none;
         }