Feature: implement mouse bindings

A configured mouse binding (for example `bindsym button3 kill`) runs
its command when the mouse button is pressed over parts of a container.

If the binding has no modifer, it will only run when the button is
clicked on the window titlebar.

Otherwise if the binding has a modifier, it will run over the titlebar
or any part of the contained window.

fixes #558

docs/userguide

@@ -394,6 +394,40 @@ umlauts or special characters 'and' having some comfortably reachable key
 bindings. For example, when typing, capslock+1 or capslock+2 for switching
 workspaces is totally convenient. Try it :-).
 
+[[mousebindings]]
+
+=== Mouse bindings
+
+A mouse binding makes i3 execute a command upon pressing a specific mouse
+button in the scope of the clicked container (see <<command_criteria>>). You
+can configure mouse bindings in a similar way to key bindings.
+
+*Syntax*:
+----------------------------------
+bindsym [Modifiers+]button[n] command
+----------------------------------
+
+If the binding has no modifiers, it will only run when you click on the
+titlebar of the window. Otherwise, it will run when any part of the window is
+clicked.
+
+*Examples*:
+--------------------------------
+# The middle button over a titlebar kills the window
+bindsym button2 kill
+
+# The middle button and a modifer over any part of the window kills the window
+bindsym $mod+button2 kill
+
+# The right button toggles floating
+bindsym button3 floating toggle
+bindsym $mod+button3 floating toggle
+
+# The side buttons move the window around
+bindsym button9 move left
+bindsym button8 move right
+--------------------------------
+
 [[floating_modifier]]
 
 === The floating modifier

include/bindings.h

@@ -61,9 +61,10 @@ void switch_mode(const char *new_mode);
 void check_for_duplicate_bindings(struct context *context);
 
 /**
- * Runs the given binding and handles parse errors. Returns a CommandResult for
+ * Runs the given binding and handles parse errors. If con is passed, it will
- * running the binding's command. Caller should render tree if
+ * execute the command binding with that container selected by criteria.
- * needs_tree_render is true. Free with command_result_free().
+ * Returns a CommandResult for running the binding's command. Caller should
+ * render tree if needs_tree_render is true. Free with command_result_free().
  *
  */
-CommandResult *run_binding(Binding *bind);
+CommandResult *run_binding(Binding *bind, Con *con);

src/bindings.c

@@ -379,18 +379,25 @@ void check_for_duplicate_bindings(struct context *context) {
 }
 
 /*
- * Runs the given binding and handles parse errors. Returns a CommandResult for
+ * Runs the given binding and handles parse errors. If con is passed, it will
- * running the binding's command. Caller should render tree if
+ * execute the command binding with that container selected by criteria.
- * needs_tree_render is true. Free with command_result_free().
+ * Returns a CommandResult for running the binding's command. Caller should
+ * render tree if needs_tree_render is true. Free with command_result_free().
  *
  */
-CommandResult *run_binding(Binding *bind) {
+CommandResult *run_binding(Binding *bind, Con *con) {
+    char *command;
+
     /* We need to copy the command since “reload” may be part of the command,
      * and then the memory that bind->command points to may not contain the
      * same data anymore. */
-    char *command_copy = sstrdup(bind->command);
+    if (con == NULL)
-    CommandResult *result = parse_command(command_copy, NULL);
+        command = sstrdup(bind->command);
-    free(command_copy);
+    else
+        sasprintf(&command, "[con_id=\"%d\"] %s", con, bind->command);
+
+    CommandResult *result = parse_command(command, NULL);
+    free(command);
 
     if (result->needs_tree_render)
         tree_render();

src/click.c

@@ -177,6 +177,29 @@ static int route_click(Con *con, xcb_button_press_event_t *event, const bool mod
     if (con->parent->type == CT_DOCKAREA)
         goto done;
 
+    /* if the user has bound an action to this click, it should override the
+     * default behavior. */
+    if (dest == CLICK_DECORATION || dest == CLICK_INSIDE) {
+        Binding *bind = get_binding_from_xcb_event((xcb_generic_event_t *)event);
+        /* clicks over a window decoration will always trigger the binding and
+         * clicks on the inside of the window will only trigger a binding if it
+         * has modifiers. */
+        if (bind && (dest == CLICK_DECORATION || (bind->mods && dest == CLICK_INSIDE))) {
+            CommandResult *result = run_binding(bind, con);
+
+            /* ASYNC_POINTER eats the event */
+            xcb_allow_events(conn, XCB_ALLOW_ASYNC_POINTER, event->time);
+            xcb_flush(conn);
+
+            if (result->needs_tree_render)
+                tree_render();
+
+            command_result_free(result);
+
+            return 0;
+        }
+    }
+
     /* Any click in a workspace should focus that workspace. If the
      * workspace is on another output we need to do a workspace_show in
      * order for i3bar (and others) to notice the change in workspace. */
@@ -300,6 +323,7 @@ done:
     xcb_allow_events(conn, XCB_ALLOW_REPLAY_POINTER, event->time);
     xcb_flush(conn);
     tree_render();
+
     return 0;
 }
 

src/key_press.c

@@ -30,7 +30,7 @@ void handle_key_press(xcb_key_press_event_t *event) {
     if (bind == NULL)
         return;
 
-    CommandResult *result = run_binding(bind);
+    CommandResult *result = run_binding(bind, NULL);
 
     if (result->needs_tree_render)
         tree_render();