From f8136c627d4a3572ffc85ed8706c3ef40e7557ea Mon Sep 17 00:00:00 2001
From: Roman Chistokhodov <freeslave93@gmail.com>
Date: Sun, 1 Oct 2017 05:23:45 +0300
Subject: [PATCH 1/2] Add support for borderless (undecorated) window on sdl2
 and x11 platforms

---
 src/dlangui/platforms/common/platform.d |  2 ++
 src/dlangui/platforms/sdl/sdlapp.d      |  2 ++
 src/dlangui/platforms/x11/x11app.d      | 32 +++++++++++++++++++++++++
 3 files changed, 36 insertions(+)

diff --git a/src/dlangui/platforms/common/platform.d b/src/dlangui/platforms/common/platform.d
index f58767d4..0e66885d 100644
--- a/src/dlangui/platforms/common/platform.d
+++ b/src/dlangui/platforms/common/platform.d
@@ -54,6 +54,8 @@ enum WindowFlag : uint {
     Modal = 4,
     /// measure window size on window.show() - helps if you want scrollWindow but on show() you want to set window to mainWidget measured size
     MeasureSize = 8,
+    /// window without decorations
+    Borderless = 16,
 }
 
 /// Window states
diff --git a/src/dlangui/platforms/sdl/sdlapp.d b/src/dlangui/platforms/sdl/sdlapp.d
index 8d3d0aaa..265aecd6 100644
--- a/src/dlangui/platforms/sdl/sdlapp.d
+++ b/src/dlangui/platforms/sdl/sdlapp.d
@@ -249,6 +249,8 @@ class SDLWindow : Window {
             windowFlags |= SDL_WINDOW_RESIZABLE;
         if (flags & WindowFlag.Fullscreen)
             windowFlags |= SDL_WINDOW_FULLSCREEN;
+        if (flags & WindowFlag.Borderless)
+            windowFlags = SDL_WINDOW_BORDERLESS;
         windowFlags |= SDL_WINDOW_ALLOW_HIGHDPI;
         static if (ENABLE_OPENGL) {
             if (_enableOpengl)
diff --git a/src/dlangui/platforms/x11/x11app.d b/src/dlangui/platforms/x11/x11app.d
index 28c584dc..54e66d01 100644
--- a/src/dlangui/platforms/x11/x11app.d
+++ b/src/dlangui/platforms/x11/x11app.d
@@ -44,6 +44,28 @@ static if (ENABLE_OPENGL) {
 alias XWindow = x11.Xlib.Window;
 alias DWindow = dlangui.platforms.common.platform.Window;
 
+private struct MwmHints
+{
+    int flags;
+    int functions;
+    int decorations;
+    int input_mode;
+    int status;
+}
+
+private enum
+{
+    MWM_HINTS_FUNCTIONS = (1L << 0),
+    MWM_HINTS_DECORATIONS =  (1L << 1),
+
+    MWM_FUNC_ALL = (1L << 0),
+    MWM_FUNC_RESIZE = (1L << 1),
+    MWM_FUNC_MOVE = (1L << 2),
+    MWM_FUNC_MINIMIZE = (1L << 3),
+    MWM_FUNC_MAXIMIZE = (1L << 4),
+    MWM_FUNC_CLOSE = (1L << 5)
+}
+
 private __gshared
 {
     Display * x11display;
@@ -74,6 +96,8 @@ private __gshared
     Atom   atom_NET_WM_STATE_HIDDEN;
     Atom   atom_NET_WM_STATE_FULLSCREEN;
 
+    Atom   atom_MOTIF_WM_HINTS;
+
     Atom   atom_DLANGUI_TIMER_EVENT;
     Atom   atom_DLANGUI_TASK_EVENT;
     Atom   atom_DLANGUI_CLOSE_WINDOW_EVENT;
@@ -98,6 +122,7 @@ static void setupX11Atoms()
     atom_NET_WM_STATE_MAXIMIZED_HORZ = XInternAtom(x11display, "_NET_WM_STATE_MAXIMIZED_HORZ", True);
     atom_NET_WM_STATE_HIDDEN = XInternAtom(x11display, "_NET_WM_STATE_HIDDEN", True);
     atom_NET_WM_STATE_FULLSCREEN = XInternAtom(x11display, "_NET_WM_STATE_FULLSCREEN", True);
+    atom_MOTIF_WM_HINTS = XInternAtom(x11display, "_MOTIF_WM_HINTS", True);
 
     atom_DLANGUI_TIMER_EVENT     = XInternAtom(x11display, "DLANGUI_TIMER_EVENT", False);
     atom_DLANGUI_TASK_EVENT     = XInternAtom(x11display, "DLANGUI_TASK_EVENT", False);
@@ -335,6 +360,13 @@ class X11Window : DWindow {
             else
                 Log.w("Missing _NET_WM_STATE_FULLSCREEN atom");
         }
+        if (flags & WindowFlag.Borderless) {
+            if (atom_MOTIF_WM_HINTS != None) {
+                MwmHints hints;
+                hints.flags = MWM_HINTS_DECORATIONS;
+                XChangeProperty(x11display, _win, atom_MOTIF_WM_HINTS, atom_MOTIF_WM_HINTS, 32, PropModeReplace, cast(ubyte*)&hints, hints.sizeof / 4);
+            }
+        }
         if (flags & WindowFlag.Modal) {
             if (_parent) {
                 XSetTransientForHint(x11display, _win, _parent._win);

From 0289d1762505a254f5abac331e6cb521ac2ea95b Mon Sep 17 00:00:00 2001
From: Roman Chistokhodov <freeslave93@gmail.com>
Date: Sun, 1 Oct 2017 16:07:35 +0300
Subject: [PATCH 2/2] Implement WindowFlag.Borderless for Windows

---
 src/dlangui/platforms/windows/winapp.d | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/dlangui/platforms/windows/winapp.d b/src/dlangui/platforms/windows/winapp.d
index 4f1c2f4b..4d2781bd 100644
--- a/src/dlangui/platforms/windows/winapp.d
+++ b/src/dlangui/platforms/windows/winapp.d
@@ -282,6 +282,9 @@ class Win32Window : Window {
             _dy = screenRc.height;
             ws = WS_POPUP;
         }
+        if (flags & WindowFlag.Borderless) {
+            ws = WS_POPUP | WS_SYSMENU;
+        }
 
 
         _hwnd = CreateWindowW(toUTF16z(WIN_CLASS_NAME),      // window class name