From 43b07b122a1fa460bdda3edc529726e3b6a6463d Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Daniel=20Ekl=C3=B6f?= <daniel@ekloef.se>
Date: Sat, 29 Feb 2020 12:52:55 +0100
Subject: [PATCH] input: csd: add a small delay before initiating a move

This ensures the user has time to double-click to toggle the maximized
state.
---
 input.c   | 41 ++++++++++++++++++++++++++++++++++++-----
 wayland.c |  4 ++++
 wayland.h |  3 +++
 3 files changed, 43 insertions(+), 5 deletions(-)

diff --git a/input.c b/input.c
index a7a78a5d..1db3541f 100644
--- a/input.c
+++ b/input.c
@@ -8,6 +8,7 @@
 #include <sys/mman.h>
 #include <sys/time.h>
 #include <sys/timerfd.h>
+#include <sys/epoll.h>
 
 #include <linux/input-event-codes.h>
 
@@ -833,6 +834,19 @@ wl_pointer_motion(void *data, struct wl_pointer *wl_pointer,
         term, wayl->mouse.button, wayl->mouse.row, wayl->mouse.col);
 }
 
+static bool
+fdm_csd_move(struct fdm *fdm, int fd, int events, void *data)
+{
+    struct wl_window *win = data;
+    struct wayland *wayl = win->term->wl;
+
+    fdm_del(fdm, fd);
+    win->csd.move_timeout_fd = -1;
+
+    xdg_toplevel_move(win->xdg_toplevel, wayl->seat, win->csd.serial);
+    return true;
+}
+
 static void
 wl_pointer_button(void *data, struct wl_pointer *wl_pointer,
                   uint32_t serial, uint32_t time, uint32_t button, uint32_t state)
@@ -891,16 +905,33 @@ wl_pointer_button(void *data, struct wl_pointer *wl_pointer,
     case TERM_SURF_TITLE:
         if (state == WL_POINTER_BUTTON_STATE_PRESSED) {
 
+            struct wl_window *win = term->window;
+
             /* Toggle maximized state on double-click */
             if (button == BTN_LEFT && wayl->mouse.count == 2) {
-                if (term->window->is_maximized)
-                    xdg_toplevel_unset_maximized(term->window->xdg_toplevel);
+                if (win->is_maximized)
+                    xdg_toplevel_unset_maximized(win->xdg_toplevel);
                 else
-                    xdg_toplevel_set_maximized(term->window->xdg_toplevel);
+                    xdg_toplevel_set_maximized(win->xdg_toplevel);
             }
 
-            else if (button == BTN_LEFT)
-                xdg_toplevel_move(term->window->xdg_toplevel, term->wl->seat, serial);
+            else if (button == BTN_LEFT && win->csd.move_timeout_fd == -1) {
+                const struct itimerspec timeout = {
+                    .it_value = {.tv_nsec = 100000000},
+                };
+
+                int fd = timerfd_create(CLOCK_MONOTONIC, TFD_CLOEXEC | TFD_NONBLOCK);
+                if (fd >= 0 &&
+                    timerfd_settime(fd, 0, &timeout, NULL) == 0 &&
+                    fdm_add(wayl->fdm, fd, EPOLLIN, &fdm_csd_move, win))
+                {
+                    win->csd.move_timeout_fd = fd;
+                    win->csd.serial = serial;
+                } else {
+                    LOG_ERRNO("failed to configure XDG toplevel move timer FD");
+                    close(fd);
+                }
+            }
         }
         return;
 
diff --git a/wayland.c b/wayland.c
index 5d3a30df..7322a32f 100644
--- a/wayland.c
+++ b/wayland.c
@@ -1014,6 +1014,7 @@ wayl_win_init(struct terminal *term)
     struct wl_window *win = calloc(1, sizeof(*win));
     win->term = term;
     win->use_csd = CSD_UNKNOWN;
+    win->csd.move_timeout_fd = -1;
 
     win->surface = wl_compositor_create_surface(wayl->compositor);
     if (win->surface == NULL) {
@@ -1072,6 +1073,9 @@ wayl_win_destroy(struct wl_window *win)
     if (win == NULL)
         return;
 
+    if (win->csd.move_timeout_fd != -1)
+        close(win->csd.move_timeout_fd);
+
     /*
      * First, unmap all surfaces to trigger things like
      * keyboard_leave() and wl_pointer_leave().
diff --git a/wayland.h b/wayland.h
index a18b40a3..4d73be42 100644
--- a/wayland.h
+++ b/wayland.h
@@ -106,6 +106,9 @@ struct wl_window {
         struct wl_surface *surface[5];
         struct wl_subsurface *sub_surface[5];
         int x, y;
+
+        int move_timeout_fd;
+        uint32_t serial;
     } csd;
 
     /* Scrollback search */