From 0321f3dcfb576763625a74392332e627ad5ece1b Mon Sep 17 00:00:00 2001
From: Aaron Hill <aa1ronham@gmail.com>
Date: Mon, 29 May 2017 12:51:49 -0400
Subject: [PATCH] Implement FocusIn/FocusOut reports (#589)

Implements sending FocusIn/FocusOut events, as defined at
http://invisible-island.net/xterm/ctlseqs/ctlseqs.html#h2-FocusIn_FocusOut
---
 src/ansi.rs     |  3 +++
 src/event.rs    | 13 +++++++++----
 src/input.rs    | 13 +++++++++++++
 src/term/mod.rs | 27 +++++++++++++++------------
 4 files changed, 40 insertions(+), 16 deletions(-)

diff --git a/src/ansi.rs b/src/ansi.rs
index a2adcf90..cca8fe28 100644
--- a/src/ansi.rs
+++ b/src/ansi.rs
@@ -302,6 +302,8 @@ pub enum Mode {
     ReportMouseClicks = 1000,
     /// ?1002
     ReportMouseMotion = 1002,
+    /// ?1004
+    ReportFocusInOut = 1004,
     /// ?1006
     SgrMouse = 1006,
     /// ?1049
@@ -325,6 +327,7 @@ impl Mode {
                 25 => Mode::ShowCursor,
                 1000 => Mode::ReportMouseClicks,
                 1002 => Mode::ReportMouseMotion,
+                1004 => Mode::ReportFocusInOut,
                 1006 => Mode::SgrMouse,
                 1049 => Mode::SwapScreenAndSetRestoreCursor,
                 2004 => Mode::BracketedPaste,
diff --git a/src/event.rs b/src/event.rs
index 32b0e9d6..2d50234d 100644
--- a/src/event.rs
+++ b/src/event.rs
@@ -251,14 +251,19 @@ impl<N: Notify> Processor<N> {
                 *hide_cursor = false;
                 processor.on_mouse_wheel(scroll_delta, touch_phase);
             },
-            glutin::Event::Focused(true) |
             glutin::Event::Refresh |
             glutin::Event::Awakened => {
                 processor.ctx.terminal.dirty = true;
             },
-            glutin::Event::Focused(false) => {
-                *hide_cursor = false;
-            },
+            glutin::Event::Focused(is_focused) => {
+                if is_focused {
+                    processor.ctx.terminal.dirty = true;
+                } else {
+                    *hide_cursor = false;
+                }
+
+                processor.on_focus_change(is_focused);
+            }
             _ => (),
         }
     }
diff --git a/src/input.rs b/src/input.rs
index 47374e47..f3efdf14 100644
--- a/src/input.rs
+++ b/src/input.rs
@@ -381,6 +381,19 @@ impl<'a, A: ActionContext + 'a> Processor<'a, A> {
         }
     }
 
+    pub fn on_focus_change(&mut self, is_focused: bool) {
+        if self.ctx.terminal_mode().contains(mode::FOCUS_IN_OUT) {
+            let chr = if is_focused {
+                "I"
+            } else {
+                "O"
+            };
+
+            let msg = format!("\x1b[{}", chr);
+            self.ctx.write_to_pty(msg.into_bytes());
+        }
+    }
+
     pub fn mouse_input(&mut self, state: ElementState, button: MouseButton) {
         if let MouseButton::Left = button {
             let state = mem::replace(&mut self.ctx.mouse_mut().left_button_state, state);
diff --git a/src/term/mod.rs b/src/term/mod.rs
index f600347b..1316ac20 100644
--- a/src/term/mod.rs
+++ b/src/term/mod.rs
@@ -252,18 +252,19 @@ impl<'a> Iterator for RenderableCellsIter<'a> {
 pub mod mode {
     bitflags! {
         pub flags TermMode: u16 {
-            const SHOW_CURSOR         = 0b00000000001,
-            const APP_CURSOR          = 0b00000000010,
-            const APP_KEYPAD          = 0b00000000100,
-            const MOUSE_REPORT_CLICK  = 0b00000001000,
-            const BRACKETED_PASTE     = 0b00000010000,
-            const SGR_MOUSE           = 0b00000100000,
-            const MOUSE_MOTION        = 0b00001000000,
-            const LINE_WRAP           = 0b00010000000,
-            const LINE_FEED_NEW_LINE  = 0b00100000000,
-            const ORIGIN              = 0b01000000000,
-            const INSERT              = 0b10000000000,
-            const ANY                 = 0b11111111111,
+            const SHOW_CURSOR         = 0b000000000001,
+            const APP_CURSOR          = 0b000000000010,
+            const APP_KEYPAD          = 0b000000000100,
+            const MOUSE_REPORT_CLICK  = 0b000000001000,
+            const BRACKETED_PASTE     = 0b000000010000,
+            const SGR_MOUSE           = 0b000000100000,
+            const MOUSE_MOTION        = 0b000001000000,
+            const LINE_WRAP           = 0b000010000000,
+            const LINE_FEED_NEW_LINE  = 0b000100000000,
+            const ORIGIN              = 0b001000000000,
+            const INSERT              = 0b010000000000,
+            const FOCUS_IN_OUT        = 0b100000000000,
+            const ANY                 = 0b111111111111,
             const NONE                = 0,
         }
     }
@@ -1631,6 +1632,7 @@ impl ansi::Handler for Term {
             ansi::Mode::CursorKeys => self.mode.insert(mode::APP_CURSOR),
             ansi::Mode::ReportMouseClicks => self.mode.insert(mode::MOUSE_REPORT_CLICK),
             ansi::Mode::ReportMouseMotion => self.mode.insert(mode::MOUSE_MOTION),
+            ansi::Mode::ReportFocusInOut => self.mode.insert(mode::FOCUS_IN_OUT),
             ansi::Mode::BracketedPaste => self.mode.insert(mode::BRACKETED_PASTE),
             ansi::Mode::SgrMouse => self.mode.insert(mode::SGR_MOUSE),
             ansi::Mode::LineWrap => self.mode.insert(mode::LINE_WRAP),
@@ -1657,6 +1659,7 @@ impl ansi::Handler for Term {
             ansi::Mode::CursorKeys => self.mode.remove(mode::APP_CURSOR),
             ansi::Mode::ReportMouseClicks => self.mode.remove(mode::MOUSE_REPORT_CLICK),
             ansi::Mode::ReportMouseMotion => self.mode.remove(mode::MOUSE_MOTION),
+            ansi::Mode::ReportFocusInOut => self.mode.remove(mode::FOCUS_IN_OUT),
             ansi::Mode::BracketedPaste => self.mode.remove(mode::BRACKETED_PASTE),
             ansi::Mode::SgrMouse => self.mode.remove(mode::SGR_MOUSE),
             ansi::Mode::LineWrap => self.mode.remove(mode::LINE_WRAP),