From d4b8fd9f5a43b05af9fdb882e0f7941af78266eb Mon Sep 17 00:00:00 2001
From: rerion <phearion@gmail.com>
Date: Fri, 6 Jan 2017 21:59:35 +0100
Subject: [PATCH] Add methods allowing creation of X11 window with specified
 visual and screen

---
 src/api/x11/window.rs              | 33 +++++++++++++++++++++++-------
 src/os/unix.rs                     | 18 +++++++++++++++-
 src/platform/linux/api_dispatch.rs | 10 ++++++---
 3 files changed, 50 insertions(+), 11 deletions(-)

diff --git a/src/api/x11/window.rs b/src/api/x11/window.rs
index cdc2d62b..276a2415 100644
--- a/src/api/x11/window.rs
+++ b/src/api/x11/window.rs
@@ -14,6 +14,7 @@ use std::time::Duration;
 
 use CursorState;
 use WindowAttributes;
+use platform::PlatformSpecificWindowBuilderAttributes;
 
 use platform::MonitorId as PlatformMonitorId;
 
@@ -282,7 +283,8 @@ pub struct Window {
 }
 
 impl Window {
-    pub fn new(display: &Arc<XConnection>, window_attrs: &WindowAttributes)
+    pub fn new(display: &Arc<XConnection>, window_attrs: &WindowAttributes,
+               pl_attribs: &PlatformSpecificWindowBuilderAttributes)
                -> Result<Window, CreationError>
     {
         let dimensions = {
@@ -303,9 +305,12 @@ impl Window {
 
         };
 
-        let screen_id = match window_attrs.monitor {
-            Some(PlatformMonitorId::X(MonitorId(_, monitor))) => monitor as i32,
-            _ => unsafe { (display.xlib.XDefaultScreen)(display.display) },
+        let screen_id = match pl_attribs.screen_id {
+            Some(id) => id,
+            None => match window_attrs.monitor {
+                Some(PlatformMonitorId::X(MonitorId(_, monitor))) => monitor as i32,
+                _ => unsafe { (display.xlib.XDefaultScreen)(display.display) },
+            }
         };
 
         // finding the mode to switch to if necessary
@@ -347,7 +352,12 @@ impl Window {
         // creating
         let mut set_win_attr = {
             let mut swa: ffi::XSetWindowAttributes = unsafe { mem::zeroed() };
-            swa.colormap = 0;
+            swa.colormap = if let Some(vi) = pl_attribs.visual_infos {
+                unsafe {
+                    let visual = vi.visual;
+                    (display.xlib.XCreateColormap)(display.display, root, visual, ffi::AllocNone)
+                }
+            } else { 0 };
             swa.event_mask = ffi::ExposureMask | ffi::StructureNotifyMask |
                 ffi::VisibilityChangeMask | ffi::KeyPressMask | ffi::PointerMotionMask |
                 ffi::KeyReleaseMask | ffi::ButtonPressMask |
@@ -369,8 +379,17 @@ impl Window {
         // finally creating the window
         let window = unsafe {
             let win = (display.xlib.XCreateWindow)(display.display, root, 0, 0, dimensions.0 as libc::c_uint,
-                dimensions.1 as libc::c_uint, 0, ffi::CopyFromParent, ffi::InputOutput as libc::c_uint,
-                ffi::CopyFromParent as *mut _, window_attributes,
+                dimensions.1 as libc::c_uint, 0,
+                match pl_attribs.visual_infos {
+                    Some(vi) => vi.depth,
+                    None => ffi::CopyFromParent
+                },
+                ffi::InputOutput as libc::c_uint,
+                match pl_attribs.visual_infos {
+                    Some(vi) => vi.visual,
+                    None => ffi::CopyFromParent as *mut _
+                },
+                window_attributes,
                 &mut set_win_attr);
             display.check_errors().expect("Failed to call XCreateWindow");
             win
diff --git a/src/os/unix.rs b/src/os/unix.rs
index d325f135..f983925f 100644
--- a/src/os/unix.rs
+++ b/src/os/unix.rs
@@ -1,11 +1,13 @@
 #![cfg(any(target_os = "linux", target_os = "dragonfly", target_os = "freebsd", target_os = "openbsd"))]
 
 use std::sync::Arc;
+use std::ptr;
 use libc;
 use Window;
 use platform::Window as LinuxWindow;
 use WindowBuilder;
 use api::x11::XConnection;
+use api::x11::ffi::XVisualInfo;
 
 use wayland_client::protocol::wl_display::WlDisplay;
 use wayland_client::protocol::wl_surface::WlSurface;
@@ -142,8 +144,22 @@ impl WindowExt for Window {
 
 /// Additional methods on `WindowBuilder` that are specific to Unix.
 pub trait WindowBuilderExt {
-
+    fn with_visual(self, visual_infos: *const XVisualInfo) -> WindowBuilder;
+    fn with_screen(self, screen_id: i32) -> WindowBuilder;
 }
 
 impl WindowBuilderExt for WindowBuilder {
+    #[inline]
+    fn with_visual(mut self, visual_infos: *const XVisualInfo) -> WindowBuilder {
+        self.platform_specific.visual_infos = Some(
+            unsafe { ptr::read(visual_infos) }
+            );
+        self
+    }
+
+    #[inline]
+    fn with_screen(mut self, screen_id: i32) -> WindowBuilder {
+        self.platform_specific.screen_id = Some(screen_id);
+        self
+    }
 }
diff --git a/src/platform/linux/api_dispatch.rs b/src/platform/linux/api_dispatch.rs
index 7b14c265..66deb688 100644
--- a/src/platform/linux/api_dispatch.rs
+++ b/src/platform/linux/api_dispatch.rs
@@ -13,9 +13,13 @@ use api::x11;
 use api::x11::XConnection;
 use api::x11::XError;
 use api::x11::XNotSupported;
+use api::x11::ffi::XVisualInfo;
 
 #[derive(Clone, Default)]
-pub struct PlatformSpecificWindowBuilderAttributes;
+pub struct PlatformSpecificWindowBuilderAttributes {
+    pub visual_infos: Option<XVisualInfo>,
+    pub screen_id: Option<i32>,
+}
 
 enum Backend {
     X(Arc<XConnection>),
@@ -165,7 +169,7 @@ impl<'a> Iterator for WaitEventsIterator<'a> {
 
 impl Window {
     #[inline]
-    pub fn new(window: &WindowAttributes, _: &PlatformSpecificWindowBuilderAttributes)
+    pub fn new(window: &WindowAttributes, pl_attribs: &PlatformSpecificWindowBuilderAttributes)
                -> Result<Window, CreationError>
     {
         match *BACKEND {
@@ -174,7 +178,7 @@ impl Window {
             },
 
             Backend::X(ref connec) => {
-                x11::Window::new(connec, window).map(Window::X)
+                x11::Window::new(connec, window, pl_attribs).map(Window::X)
             },
 
             Backend::Error(ref error) => {