Re: Creating a "borderless" frame (without WM chrome) (was Re: Could x-show-tip be reimplemented in Elisp? How does one create borderless frames from Elisp?)

["Clément Pit--Claudel" <clement.pit@gmail.com>]

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On 02/17/2016 08:49 AM, Chris Feng wrote:
>>> * add a frame parameter to frame_parms in frame.c, say "chromeless"
>>
>> I'd prefer "decorated" as in gtk_window_set-decorated.
> 
> Agree.  We call it "decoration" in X almost exclusively.
> 
>>> * add an x_set_chromeless slot in each of frame_parm_handler
>>> x_frame_parm_handlers[], frame_parm_handler w32_frame_parm_handlers[],
>>> frame_parm_handler ns_frame_parm_handlers[]; for the last two point to 0 for
>>> now; for the first one point to a new function x_set_chromeless.
>>> * In x-create-frame, add something like
>>>      x_default_parameter (f, parms, Qchromeless, Qnil,
>>>                           "chromeless", "Chromeless", RES_TYPE_BOOLEAN);
> 
> I don't think we need to make this customizable through X resources,
> so the fifth and sixth parameters to x_default_parameter should be
> NULL.

Thanks. I've attached a rough patch draft (that is, frames are decorated by default, but (make-frame '((decorated . nil))) creates an undecorated frame), which works with --with-x-toolkit=none.

>> For X I doubt that it's always possible to add/remove the decorations of
>> an existing frame.
> 
> Yes but it may require remapping if it's already mapped.

Got it; is this why the attached patch doesn't do anything with Gtk? I looked at the Xlib documentation, but I'm not sure how to check if the window is already mapped, and only remap it in that case.

Cheers,
Clément.

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From e4cd5c03947a29e73fe7d75167a12ef0b2ed55f3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Cl=C3=A9ment=20Pit--Claudel?= <clement.pitclaudel@live.com>
Date: Tue, 16 Feb 2016 18:49:57 -0500
Subject: [PATCH] Prototype for undecorated frames

Only works with --with-x-toolkit=none
---
 src/frame.c  |  2 ++
 src/nsfns.m  |  1 +
 src/w32fns.c |  1 +
 src/xfns.c   | 14 ++++++++++++++
 4 files changed, 18 insertions(+)

diff --git a/src/frame.c b/src/frame.c
index 8c86afe..0c74dce 100644
--- a/src/frame.c
+++ b/src/frame.c
@@ -3065,6 +3065,7 @@ static const struct frame_parm_table frame_parms[] =
   {"fullscreen",                SYMBOL_INDEX (Qfullscreen)},
   {"font-backend",		SYMBOL_INDEX (Qfont_backend)},
   {"alpha",			SYMBOL_INDEX (Qalpha)},
+  {"decorated",			SYMBOL_INDEX (Qdecorated)},
   {"sticky",			SYMBOL_INDEX (Qsticky)},
   {"tool-bar-position",		SYMBOL_INDEX (Qtool_bar_position)},
 };
@@ -4982,6 +4983,7 @@ syms_of_frame (void)
 #endif
 
   DEFSYM (Qalpha, "alpha");
+  DEFSYM (Qdecorated, "decorated");
   DEFSYM (Qauto_lower, "auto-lower");
   DEFSYM (Qauto_raise, "auto-raise");
   DEFSYM (Qborder_color, "border-color");
diff --git a/src/nsfns.m b/src/nsfns.m
index eda94c4..346c1a6 100644
--- a/src/nsfns.m
+++ b/src/nsfns.m
@@ -1006,6 +1006,7 @@ frame_parm_handler ns_frame_parm_handlers[] =
   x_set_fullscreen, /* generic OK */
   x_set_font_backend, /* generic OK */
   x_set_alpha,
+  0, /* x_set_decorated */
   0, /* x_set_sticky */
   0, /* x_set_tool_bar_position */
 };
diff --git a/src/w32fns.c b/src/w32fns.c
index a5018ae..226246b 100644
--- a/src/w32fns.c
+++ b/src/w32fns.c
@@ -9258,6 +9258,7 @@ frame_parm_handler w32_frame_parm_handlers[] =
   x_set_fullscreen,
   x_set_font_backend,
   x_set_alpha,
+  0, /* x_set_decorated */
   0, /* x_set_sticky */
   0, /* x_set_tool_bar_position */
 };
diff --git a/src/xfns.c b/src/xfns.c
index 20ac627..56bae7ce 100644
--- a/src/xfns.c
+++ b/src/xfns.c
@@ -3511,6 +3511,8 @@ This function is an internal primitive--use `make-frame' instead.  */)
 		       RES_TYPE_NUMBER);
   x_default_parameter (f, parms, Qalpha, Qnil,
 		       "alpha", "Alpha", RES_TYPE_NUMBER);
+  x_default_parameter (f, parms, Qdecorated, Qt,
+                       NULL, NULL, RES_TYPE_BOOLEAN);
 
 #if defined (USE_X_TOOLKIT) || defined (USE_GTK)
   /* Create the menu bar.  */
@@ -5773,6 +5775,17 @@ compute_tip_xy (struct frame *f, Lisp_Object parms, Lisp_Object dx, Lisp_Object
     *root_x = min_x;
 }
 
+void
+x_set_decorated (struct frame *f, Lisp_Object new_value, Lisp_Object old_value)
+{
+  XSetWindowAttributes attributes;
+  attributes.override_redirect = NILP(new_value) ? True : False;
+
+  block_input ();
+  XChangeWindowAttributes (FRAME_X_DISPLAY (f), FRAME_X_WINDOW (f),
+                           CWOverrideRedirect, &attributes);
+  unblock_input ();
+}
 
 DEFUN ("x-show-tip", Fx_show_tip, Sx_show_tip, 1, 6, 0,
        doc: /* Show STRING in a "tooltip" window on frame FRAME.
@@ -6791,6 +6804,7 @@ frame_parm_handler x_frame_parm_handlers[] =
   x_set_fullscreen,
   x_set_font_backend,
   x_set_alpha,
+  x_set_decorated,
   x_set_sticky,
   x_set_tool_bar_position,
 };
-- 
2.7.1


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