fix(stackbar): avoid drops from variable updates

This commit ensures that when we call methods to change
Container.stackbar we are not unintentionally invoking a Drop which
kills a stackbar window that already exists.

Checks have been added to make sure that we not change the value of the
stackbar variable if it is already an Option::Some.

re #746 re #792

komorebi/src/container.rs

@@ -159,27 +159,34 @@ impl Container {
     }
 
     pub fn set_stackbar_mode(&mut self, mode: StackbarMode) {
-        self.stackbar = match mode {
-            StackbarMode::Always => Stackbar::create().ok(),
-            StackbarMode::Never => None,
-            StackbarMode::OnStack => {
-                if self.windows().len() > 1 && self.stackbar().is_none() {
-                    Stackbar::create().ok()
-                } else {
-                    None
+        match mode {
+            StackbarMode::Always => {
+                if self.stackbar.is_none() {
+                    self.stackbar = Stackbar::create().ok();
                 }
             }
-        };
-    }
+            StackbarMode::Never => {
+                if self.stackbar.is_some() {
+                    self.stackbar = None
+                }
+            }
+            StackbarMode::OnStack => {
+                if self.windows().len() > 1 && self.stackbar().is_none() {
+                    self.stackbar = Stackbar::create().ok();
+                }
 
-    pub fn renew_stackbar(&mut self) {
-        match &self.stackbar {
-            None => {}
-            Some(stackbar) => {
-                if !WindowsApi::is_window(stackbar.hwnd()) {
-                    self.stackbar = Stackbar::create().ok()
+                if self.windows().len() == 1 && self.stackbar.is_some() {
+                    self.stackbar = None;
                 }
             }
         }
     }
+
+    pub fn renew_stackbar(&mut self) {
+        if let Some(stackbar) = &self.stackbar {
+            if !WindowsApi::is_window(stackbar.hwnd()) {
+                self.stackbar = Stackbar::create().ok()
+            }
+        }
+    }
 }

komorebi/src/stackbar.rs

@@ -74,6 +74,7 @@ pub struct Stackbar {
 impl Drop for Stackbar {
     fn drop(&mut self) {
         if !self.is_cloned {
+            tracing::debug!("dropping and calling close_window on stackbar");
             let _ = WindowsApi::close_window(self.hwnd());
         }
     }
@@ -87,6 +88,7 @@ impl Clone for Stackbar {
         }
     }
 }
+
 impl Stackbar {
     unsafe extern "system" fn window_proc(
         hwnd: HWND,