fix(wm): enforce valid hwnd check for border fns

This commit ensures that the active window border has non-zero HWND
before attempting to either hide it or set the border position. This is
required as the border is only initialized when a komorebic command is
received, meaning that the default value of 0 will never change if a
user decides to use komorebi without the active window border.

Most notably this commit fixes an issue where users who did not have the
active window border enabled would not be able to move away from an
empty workspace using a komorebic command.

fix #217

komorebi/src/border.rs

@@ -87,7 +87,11 @@ impl Border {
     }
 
     pub fn hide(self) -> Result<()> {
-        WindowsApi::hide_border_window(self.hwnd())
+        if self.hwnd == 0 {
+            Ok(())
+        } else {
+            WindowsApi::hide_border_window(self.hwnd())
+        }
     }
 
     pub fn set_position(
@@ -96,29 +100,33 @@ impl Border {
         invisible_borders: &Rect,
         activate: bool,
     ) -> Result<()> {
-        let mut should_expand_border = false;
-
-        let mut rect = WindowsApi::window_rect(window.hwnd())?;
-        rect.top -= invisible_borders.bottom;
-        rect.bottom += invisible_borders.bottom;
-
-        let border_overflows = BORDER_OVERFLOW_IDENTIFIERS.lock();
-        if border_overflows.contains(&window.title()?)
-            || border_overflows.contains(&window.exe()?)
-            || border_overflows.contains(&window.class()?)
-        {
-            should_expand_border = true;
-        }
+        if self.hwnd == 0 {
+            Ok(())
+        } else {
+            let mut should_expand_border = false;
 
-        if should_expand_border {
-            rect.left -= invisible_borders.left;
-            rect.top -= invisible_borders.top;
-            rect.right += invisible_borders.right;
+            let mut rect = WindowsApi::window_rect(window.hwnd())?;
+            rect.top -= invisible_borders.bottom;
             rect.bottom += invisible_borders.bottom;
-        }
 
-        *BORDER_RECT.lock() = rect;
+            let border_overflows = BORDER_OVERFLOW_IDENTIFIERS.lock();
+            if border_overflows.contains(&window.title()?)
+                || border_overflows.contains(&window.exe()?)
+                || border_overflows.contains(&window.class()?)
+            {
+                should_expand_border = true;
+            }
+
+            if should_expand_border {
+                rect.left -= invisible_borders.left;
+                rect.top -= invisible_borders.top;
+                rect.right += invisible_borders.right;
+                rect.bottom += invisible_borders.bottom;
+            }
 
-        WindowsApi::position_border_window(self.hwnd(), &rect, activate)
+            *BORDER_RECT.lock() = rect;
+
+            WindowsApi::position_border_window(self.hwnd(), &rect, activate)
+        }
     }
 }