diff --git a/etc/NEWS b/etc/NEWS index 922dfbdc246..ab9a2a5f32d 100644 --- a/etc/NEWS +++ b/etc/NEWS @@ -600,6 +600,11 @@ The two new variables, 'bidi-paragraph-start-re' and 'bidi-paragraph-separate-re', allow customization of what exactly are paragraphs, for the purposes of bidirectional display. +--- +** New variable 'x-wait-for-event-timeout'. +This controls how long Emacs will wait for updates to the graphical +state to take effect (making a frame visible, for example). + * Changes in Specialized Modes and Packages in Emacs 26.1 diff --git a/src/xterm.c b/src/xterm.c index 0b321909c85..90275763cbe 100644 --- a/src/xterm.c +++ b/src/xterm.c @@ -11029,17 +11029,22 @@ x_sync_with_move (struct frame *f, int left, int top, bool fuzzy) void x_wait_for_event (struct frame *f, int eventtype) { - int level = interrupt_input_blocked; + if (!FLOATP (Vx_wait_for_event_timeout)) + return; + int level = interrupt_input_blocked; fd_set fds; struct timespec tmo, tmo_at, time_now; int fd = ConnectionNumber (FRAME_X_DISPLAY (f)); f->wait_event_type = eventtype; - /* Set timeout to 0.1 second. Hopefully not noticeable. - Maybe it should be configurable. */ - tmo = make_timespec (0, 100 * 1000 * 1000); + /* Default timeout is 0.1 second. Hopefully not noticeable. */ + double timeout = XFLOAT_DATA (Vx_wait_for_event_timeout); + time_t timeout_seconds = (time_t) timeout; + tmo = make_timespec + (timeout_seconds, (long int) ((timeout - timeout_seconds) + * 1000 * 1000 * 1000)); tmo_at = timespec_add (current_timespec (), tmo); while (f->wait_event_type) @@ -11365,8 +11370,13 @@ xembed_send_message (struct frame *f, Time t, enum xembed_message msg, /* Change of visibility. */ -/* This function sends the request to make the frame visible, but may - return before it the frame's visibility is changed. */ +/* This tries to wait until the frame is really visible, depending on + the value of Vx_wait_for_event_timeout. + However, if the window manager asks the user where to position + the frame, this will return before the user finishes doing that. + The frame will not actually be visible at that time, + but it will become visible later when the window manager + finishes with it. */ void x_make_frame_visible (struct frame *f) @@ -11437,11 +11447,14 @@ x_make_frame_visible (struct frame *f) before we do anything else. We do this loop with input not blocked so that incoming events are handled. */ { + Lisp_Object frame; /* This must be before UNBLOCK_INPUT since events that arrive in response to the actions above will set it when they are handled. */ bool previously_visible = f->output_data.x->has_been_visible; + XSETFRAME (frame, f); + int original_left = f->left_pos; int original_top = f->top_pos; @@ -11488,6 +11501,10 @@ x_make_frame_visible (struct frame *f) unblock_input (); } + + /* Try to wait for a MapNotify event (that is what tells us when a + frame becomes visible). */ + x_wait_for_event (f, MapNotify); } } @@ -13283,6 +13300,17 @@ This should be one of the symbols `ctrl', `alt', `hyper', `meta', keysyms. The default is nil, which is the same as `super'. */); Vx_super_keysym = Qnil; + DEFVAR_LISP ("x-wait-for-event-timeout", Vx_wait_for_event_timeout, + doc: /* How long to wait for X events. + +Emacs will wait up to this many seconds to receive X events after +making changes which affect the state of the graphical interface. +Under some window managers this can take an indefinite amount of time, +so it is important to limit the wait. + +If set to a non-float value, there will be no wait at all. */); + Vx_wait_for_event_timeout = make_float (0.1); + DEFVAR_LISP ("x-keysym-table", Vx_keysym_table, doc: /* Hash table of character codes indexed by X keysym codes. */); Vx_keysym_table = make_hash_table (hashtest_eql, 900,