config/input: implement mouse bindings

* New config section, "mouse-bindings", where bindings are defined on
  the form "action=BTN_<name>
* pointer_button() handler now scans the bindings list instead of
  hardcoding primary-paste to BTN_MIDDLE.
* The implementation handles single- double- and triple clicks in the
  bindings, but there is currently no way to define anything but a
  single-click binding in the configuration.

config.c

@@ -12,6 +12,7 @@
 #include <assert.h>
 #include <errno.h>
 
+#include <linux/input-event-codes.h>
 #include <xkbcommon/xkbcommon.h>
 
 #define LOG_MODULE "config"
@@ -448,8 +449,9 @@ parse_section_csd(const char *key, const char *value, struct config *conf,
 }
 
 static bool
-parse_section_key_bindings(const char *key, const char *value, struct config *conf,
-                           const char *path, unsigned lineno)
+parse_section_key_bindings(
+    const char *key, const char *value, struct config *conf,
+    const char *path, unsigned lineno)
 {
     for (enum binding_action action = 0; action < BIND_ACTION_COUNT; action++) {
         if (strcmp(key, binding_action_map[action]) != 0)
@@ -459,7 +461,8 @@ parse_section_key_bindings(const char *key, const char *value, struct config *co
         struct xkb_keymap *keymap = xkb_keymap_new_from_names(
             ctx, &(struct xkb_rule_names){0}, XKB_KEYMAP_COMPILE_NO_FLAGS);
 
-        bool valid_combo = input_parse_key_binding_for_action(keymap, action, value, NULL);
+        bool valid_combo = input_parse_key_binding_for_action(
+            keymap, action, value, NULL);
 
         xkb_keymap_unref(keymap);
         xkb_context_unref(ctx);
@@ -479,6 +482,43 @@ parse_section_key_bindings(const char *key, const char *value, struct config *co
 
 }
 
+static bool
+parse_section_mouse_bindings(
+    const char *key, const char *value, struct config *conf,
+    const char *path, unsigned lineno)
+{
+    for (enum binding_action action = 0; action < BIND_ACTION_COUNT; action++) {
+        if (strcmp(key, binding_action_map[action]) != 0)
+            continue;
+
+        const char *map[] = {
+            [BTN_LEFT] = "BTN_LEFT",
+            [BTN_RIGHT] = "BTN_RIGHT",
+            [BTN_MIDDLE] = "BTN_MIDDLE",
+            [BTN_SIDE] = "BTN_SIDE",
+            [BTN_EXTRA] = "BTN_EXTRA",
+            [BTN_FORWARD] = "BTN_FORWARD",
+            [BTN_BACK] = "BTN_BACK",
+            [BTN_TASK] = "BTN_TASK",
+        };
+
+        for (size_t i = 0; i < ALEN(map); i++) {
+            if (map[i] == NULL || strcmp(map[i], value) != 0)
+                continue;
+
+            conf->bindings.mouse[action] = (struct mouse_binding){i, 1, action};
+            return true;
+        }
+
+        LOG_ERR("%s:%d: invalid mouse button: %s", path, lineno, value);
+        return false;
+
+    }
+
+    LOG_ERR("%s:%u: invalid key: %s", path, lineno, key);
+    return false;
+}
+
 static bool
 parse_config_file(FILE *f, struct config *conf, const char *path)
 {
@@ -488,6 +528,7 @@ parse_config_file(FILE *f, struct config *conf, const char *path)
         SECTION_CURSOR,
         SECTION_CSD,
         SECTION_KEY_BINDINGS,
+        SECTION_MOUSE_BINDINGS,
         SECTION_COUNT,
     } section = SECTION_MAIN;
 
@@ -500,11 +541,12 @@ parse_config_file(FILE *f, struct config *conf, const char *path)
         parser_fun_t fun;
         const char *name;
     } section_info[] = {
-        [SECTION_MAIN] =         {&parse_section_main, "main"},
-        [SECTION_COLORS] =       {&parse_section_colors, "colors"},
-        [SECTION_CURSOR] =       {&parse_section_cursor, "cursor"},
-        [SECTION_CSD] =          {&parse_section_csd, "csd"},
-        [SECTION_KEY_BINDINGS] = {&parse_section_key_bindings, "key-bindings"},
+        [SECTION_MAIN] =           {&parse_section_main, "main"},
+        [SECTION_COLORS] =         {&parse_section_colors, "colors"},
+        [SECTION_CURSOR] =         {&parse_section_cursor, "cursor"},
+        [SECTION_CSD] =            {&parse_section_csd, "csd"},
+        [SECTION_KEY_BINDINGS] =   {&parse_section_key_bindings, "key-bindings"},
+        [SECTION_MOUSE_BINDINGS] = {&parse_section_mouse_bindings, "mouse-bindings"},
     };
 
     static_assert(ALEN(section_info) == SECTION_COUNT, "section info array size mismatch");
@@ -699,7 +741,7 @@ config_load(struct config *conf, const char *conf_path)
                 [BIND_ACTION_SPAWN_TERMINAL] = strdup("Control+Shift+Return"),
             },
             .mouse = {
-                [BIND_ACTION_PRIMARY_PASTE] = strdup("BTN_MIDDLE"),
+                [BIND_ACTION_PRIMARY_PASTE] = {BTN_MIDDLE, 1, BIND_ACTION_PRIMARY_PASTE},
             },
             .search = {
             },
@@ -760,7 +802,6 @@ config_free(struct config conf)
 
     for (size_t i = 0; i < BIND_ACTION_COUNT; i++) {
         free(conf.bindings.key[i]);
-        free(conf.bindings.mouse[i]);
         free(conf.bindings.search[i]);
     }
 }

config.h

@@ -39,7 +39,7 @@ struct config {
     struct {
         /* Bindings for "normal" mode */
         char *key[BIND_ACTION_COUNT];
-        char *mouse[BIND_ACTION_COUNT];
+        struct mouse_binding mouse[BIND_ACTION_COUNT];
 
         /*
          * Special modes

doc/foot.5.scd

@@ -203,6 +203,18 @@ Note that _Alt_ is usually called *Mod1*.
 *fullscreen*
 	Toggles the fullscreen state. Default: _not bound_.
 
+# SECTION: mouse-bindings
+
+This section lets you override the default mouse bindings.
+
+The general format is *action*=*BTN\_<name>*, where *BTN\_<name>* is
+the name of the event code (e.g. *BTN\_LEFT*, *BTN\_RIGHT*). You can
+find the event names using *libinput debug-events*.
+
+*primary-paste*
+	Pastes from the _primary selection_. Default: _BTN_MIDDLE_.
+
+
 # FONT FORMAT
 
 The font is specified in FontConfig syntax. That is, a colon-separated

footrc

@@ -56,3 +56,6 @@
 # # minimize=<not bound>
 # # maximize=<not bound>
 # # fullscreen=<not bound>
+
+[mouse-bindings]
+# primary-paste=BTN_MIDDLE

input.c

@@ -31,6 +31,8 @@
 #include "terminal.h"
 #include "vt.h"
 
+#define ALEN(v) (sizeof(v) / sizeof(v[0]))
+
 void
 input_execute_binding(struct terminal *term, enum binding_action action,
                       uint32_t serial)
@@ -54,8 +56,7 @@ input_execute_binding(struct terminal *term, enum binding_action action,
         break;
 
     case BIND_ACTION_PRIMARY_PASTE:
-        LOG_ERR("unimplemented");
-        assert(false);
+        selection_from_primary(term);
         break;
 
     case BIND_ACTION_SEARCH_START:
@@ -321,7 +322,6 @@ keyboard_leave(void *data, struct wl_keyboard *wl_keyboard, uint32_t serial,
 static const struct key_data *
 keymap_data_for_sym(xkb_keysym_t sym, size_t *count)
 {
-#define ALEN(a) (sizeof(a) / sizeof(a[0]))
     switch (sym) {
     case XKB_KEY_Escape:       *count = ALEN(key_escape);       return key_escape;
     case XKB_KEY_Return:       *count = ALEN(key_return);       return key_return;
@@ -402,7 +402,6 @@ keymap_data_for_sym(xkb_keysym_t sym, size_t *count)
     case XKB_KEY_KP_9:         *count = ALEN(key_kp_9);         return key_kp_9;
     }
 
-    #undef ALEN
     return NULL;
 }
 
@@ -1151,11 +1150,24 @@ wl_pointer_button(void *data, struct wl_pointer *wl_pointer,
                     selection_mark_row(term, wayl->mouse.row, serial);
                     break;
                 }
-            } else {
-                if (wayl->mouse.count == 1 && button == BTN_MIDDLE &&
-                    selection_enabled(term))
-                {
-                    selection_from_primary(term);
+            }
+
+            else {
+                for (size_t i = 0; i < ALEN(wayl->conf->bindings.mouse); i++) {
+                    const struct mouse_binding *binding =
+                        &wayl->conf->bindings.mouse[i];
+
+                    if (binding->button != button) {
+                        /* Wrong button */
+                        continue;
+                    }
+
+                    if  (binding->count != wayl->mouse.count) {
+                        /* Not correct click count */
+                        continue;
+                    }
+
+                    input_execute_binding(term, binding->action, serial);
                 }
                 selection_cancel(term);
             }

wayland.h

@@ -65,6 +65,12 @@ struct key_binding {
 };
 typedef tll(struct key_binding) key_binding_list_t;
 
+struct mouse_binding {
+    uint32_t button;
+    int count;
+    enum binding_action action;
+};
+
 struct kbd {
     struct xkb_context *xkb;
     struct xkb_keymap *xkb_keymap;