From 4c4c2f5f5c81e6efb580e50ea993606160809469 Mon Sep 17 00:00:00 2001
From: Ted Yin <tederminant@gmail.com>
Date: Mon, 24 Jul 2017 20:54:06 -0400
Subject: [PATCH] add support for X input method (#691)

---
 src/display.rs  | 14 ++++++++++++++
 src/main.rs     |  2 ++
 src/term/mod.rs |  7 ++++++-
 src/window.rs   | 32 ++++++++++++++++++++++++++++++++
 4 files changed, 54 insertions(+), 1 deletion(-)

diff --git a/src/display.rs b/src/display.rs
index 0f2c526f..d1af5411 100644
--- a/src/display.rs
+++ b/src/display.rs
@@ -331,4 +331,18 @@ impl Display {
     pub fn get_window_id(&self) -> Option<usize> {
         self.window.get_window_id()
     }
+
+    /// Adjust the XIM editor position according to the new location of the cursor
+    pub fn update_ime_position(&mut self, terminal: &Term) {
+        use index::{Point, Line, Column};
+        use term::SizeInfo;
+        let Point{line: Line(row), col: Column(col)} = terminal.cursor().point;
+        let SizeInfo{cell_width: cw,
+                    cell_height: ch,
+                    padding_x: px,
+                    padding_y: py, ..} = *terminal.size_info();
+        let nspot_y = (py + (row + 1) as f32 * ch) as i16;
+        let nspot_x = (px + col as f32 * cw) as i16;
+        self.window().send_xim_spot(nspot_x, nspot_y);
+    }
 }
diff --git a/src/main.rs b/src/main.rs
index 9db5ce58..472e4144 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -172,6 +172,8 @@ fn run(mut config: Config, options: cli::Options) -> Result<(), Box<Error>> {
 
         // Maybe draw the terminal
         if terminal.needs_draw() {
+            // Try to update the position of the input method editor
+            display.update_ime_position(&terminal);
             // Handle pending resize events
             //
             // The second argument is a list of types that want to be notified
diff --git a/src/term/mod.rs b/src/term/mod.rs
index 64541b33..0a51aac3 100644
--- a/src/term/mod.rs
+++ b/src/term/mod.rs
@@ -490,7 +490,7 @@ impl IndexMut<CharsetIndex> for Charsets {
 #[derive(Default, Copy, Clone)]
 pub struct Cursor {
     /// The location of this cursor
-    point: Point,
+    pub point: Point,
 
     /// Template cell when using this cursor
     template: Cell,
@@ -1054,6 +1054,11 @@ impl Term {
         &self.mode
     }
 
+    #[inline]
+    pub fn cursor(&self) -> &Cursor {
+        &self.cursor
+    }
+
     pub fn swap_alt(&mut self) {
         if self.alt {
             let template = self.empty_cell;
diff --git a/src/window.rs b/src/window.rs
index 4fbe8631..8126454d 100644
--- a/src/window.rs
+++ b/src/window.rs
@@ -183,6 +183,8 @@ impl Window {
         title: &str
     ) -> Result<Window> {
         let event_loop = EventsLoop::new();
+
+        Window::platform_window_init();
         let window = WindowBuilder::new()
             .with_title(title);
         let context = ContextBuilder::new()
@@ -282,6 +284,36 @@ impl Window {
         }
     }
 
+    #[cfg(any(target_os = "linux", target_os = "freebsd", target_os = "dragonfly", target_os = "openbsd"))]
+    pub fn platform_window_init() {
+        /// Set up env to make XIM work correctly
+        use x11_dl::xlib;
+        use libc::{setlocale, LC_CTYPE};
+        let xlib = xlib::Xlib::open().expect("get xlib");
+        unsafe {
+            /// Use empty c string to fallback to LC_CTYPE in environment variables
+            setlocale(LC_CTYPE, b"\0".as_ptr() as *const _);
+            /// Use empty c string for implementation dependent behavior,
+            /// which might be the XMODIFIERS set in env
+            (xlib.XSetLocaleModifiers)(b"\0".as_ptr() as *const _);
+        }
+    }
+
+    /// TODO: change this directive when adding functions for other platforms
+    #[cfg(not(any(target_os = "linux", target_os = "freebsd", target_os = "dragonfly", target_os = "openbsd")))]
+    pub fn platform_window_init() {
+    }
+
+    #[cfg(any(target_os = "linux", target_os = "freebsd", target_os = "dragonfly", target_os = "openbsd"))]
+    pub fn send_xim_spot(&self, x: i16, y: i16) {
+        use glutin::os::unix::WindowExt;
+        self.window.send_xim_spot(x, y);
+    }
+
+    #[cfg(not(any(target_os = "linux", target_os = "freebsd", target_os = "dragonfly", target_os = "openbsd")))]
+    pub fn send_xim_spot(&self, x: i16, y: i16) {
+    }
+
     #[cfg(not(target_os = "macos"))]
     pub fn get_window_id(&self) -> Option<usize> {
         use glutin::os::unix::WindowExt;