config: add new mouse binding ‘launch-url’, bind to alt+BTN_LEFT

This adds a new mouse binding, launch-url (bound to Alt+BTN_LEFT by
default). When executed, the URL under the mouse pointer is
launched (with url.launcher, as usual).

This is done by calling urls_collect(), to get all currently visible
URLs (both auto-detected and OSC-8 ones), and then iterating them all
until we find one that spans the cell the mouse pointer is on.

config.c

@@ -126,6 +126,7 @@ static const char *const binding_action_map[] = {
     [BIND_ACTION_SELECT_WORD] = "select-word",
     [BIND_ACTION_SELECT_WORD_WS] = "select-word-whitespace",
     [BIND_ACTION_SELECT_ROW] = "select-row",
+    [BIND_ACTION_LAUNCH_URL] = "launch-url",
 };
 
 static const char *const search_binding_action_map[] = {
@@ -2745,6 +2746,7 @@ add_default_mouse_bindings(struct config *conf)
         {BIND_ACTION_SELECT_WORD, m_none, {.m = {BTN_LEFT, 2}}},
         {BIND_ACTION_SELECT_WORD_WS, m_ctrl, {.m = {BTN_LEFT, 2}}},
         {BIND_ACTION_SELECT_ROW, m_none, {.m = {BTN_LEFT, 3}}},
+        {BIND_ACTION_LAUNCH_URL, m_alt, {.m = {BTN_LEFT, 1}}},
     };
 
     conf->bindings.mouse.count = ALEN(bindings);

input.c

@@ -454,6 +454,41 @@ execute_binding(struct seat *seat, struct terminal *term,
             term, seat->mouse.col, seat->mouse.row, SELECTION_LINE_WISE, false);
         return true;
 
+    case BIND_ACTION_LAUNCH_URL: {
+        const int m_row = seat->mouse.row;
+        const int m_col = seat->mouse.col;
+
+        if (m_col >= 0 && m_row >= 0) {
+            url_list_t urls = tll_init();
+            urls_collect(term, URL_ACTION_LAUNCH, &urls);
+
+            tll_foreach(urls, it) {
+                const struct url *url = &it->item;
+                const int start_row = url->range.start.row;
+                const int start_col = url->range.start.col;
+                const int end_row = url->range.end.row;
+                const int end_col = url->range.end.col;
+
+                bool start_is_before_point =
+                    start_row < m_row ||
+                    (start_row == m_row && start_col <= m_col);
+
+                bool end_is_after_point =
+                    end_row > m_row ||
+                    (end_row == m_row && end_col >= m_col);
+
+                if (start_is_before_point && end_is_after_point) {
+                    url_activate(seat, term, url, serial);
+                    break;
+                }
+            }
+
+            url_list_destroy(&urls);
+        }
+
+        return true;
+    }
+
     case BIND_ACTION_COUNT:
         BUG("Invalid action type");
         return false;

key-binding.h

@@ -47,9 +47,10 @@ enum bind_action_normal {
     BIND_ACTION_SELECT_WORD,
     BIND_ACTION_SELECT_WORD_WS,
     BIND_ACTION_SELECT_ROW,
+    BIND_ACTION_LAUNCH_URL,
 
     BIND_ACTION_KEY_COUNT = BIND_ACTION_PROMPT_NEXT + 1,
-    BIND_ACTION_COUNT = BIND_ACTION_SELECT_ROW + 1,
+    BIND_ACTION_COUNT = BIND_ACTION_LAUNCH_URL + 1,
 };
 
 enum bind_action_search {