From f9126c4f8380830cab09f00a99c20cf204e0f1a9 Mon Sep 17 00:00:00 2001
From: Michael Zhang <failed.down@gmail.com>
Date: Mon, 10 Sep 2018 20:44:07 -0500
Subject: [PATCH] get active window

---
 src/gui.rs          | 10 ++++------
 xlib/src/display.rs | 12 ++++++++++++
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/src/gui.rs b/src/gui.rs
index 5528ebf..72ceb26 100644
--- a/src/gui.rs
+++ b/src/gui.rs
@@ -20,12 +20,10 @@ impl GUI {
 
     /// Get the active window.
     pub fn get_active_window(&self) -> Result<Window, ScreenshotError> {
-        Ok(self.display.get_default_root_window()?)
-        // let mut window: Window = self.display.get_default_root_window();
-        // let mut revert_to_return: i32 = RevertToParent;
-        // unsafe { XGetInputFocus(self.display, &mut window, &mut revert_to_return) };
-        // unsafe { XMapRaised(self.display, window) };
-        // window
+        self.display
+            .get_input_focus()
+            .map(|(window, _)| window)
+            .map_err(|err| err.into())
     }
 
     /// Brings up an interactive selection GUI.
diff --git a/xlib/src/display.rs b/xlib/src/display.rs
index 99f8fdb..2673d72 100644
--- a/xlib/src/display.rs
+++ b/xlib/src/display.rs
@@ -38,6 +38,18 @@ impl Display {
         };
         Ok(window)
     }
+
+    /// eturns the focus window and the current focus state.
+    pub fn get_input_focus(&self) -> Result<(Window, i32), X11Error> {
+        let mut focus_return: x::Window = 0;
+        let mut revert_to_return = 0;
+        unsafe { x::XGetInputFocus(self.inner, &mut focus_return, &mut revert_to_return) };
+        let window = Window {
+            display: self.inner,
+            inner: focus_return,
+        };
+        return Ok((window, revert_to_return));
+    }
 }
 
 impl Drop for Display {