fix: hide window controls when another window is selected (closes #1557)

docs/Contributors.md

@@ -74,6 +74,7 @@ They helped [localize the app](https://poeditor.com/join/project/8AOEZ0eAZE):
 * Jaeyong Sung
 * Jakob
 * Jakub Bartušek
+* john doe
 * Jord Nijhuis
 * Julian Nowaczyk
 * Kagurazaka Tsuki

src/ui/main-window/ThumbnailView.swift

@@ -23,6 +23,7 @@ class ThumbnailView: NSStackView {
     var shouldShowWindowControls = false
     var isShowingWindowControls = false
     var windowlessIcon = FontIcon(.newWindow)
+    var mouseIsHovering = false
 
     // for VoiceOver cursor
     override var canBecomeKeyView: Bool { true }
@@ -66,11 +67,9 @@ class ThumbnailView: NSStackView {
         [closeIcon, minimizeIcon, maximizeIcon].forEach { $0.isHidden = true }
     }
 
-    func showOrHideWindowControls(_ shouldShowWindowControls_: Bool? = nil) {
-        if let shouldShowWindowControls = shouldShowWindowControls_ {
-            self.shouldShowWindowControls = shouldShowWindowControls
-        }
-        let shouldShow = shouldShowWindowControls && !Preferences.hideColoredCircles && !window_!.isWindowlessApp && !Preferences.hideThumbnails
+    func showOrHideWindowControls(_ shouldShowWindowControls: Bool) {
+        self.shouldShowWindowControls = shouldShowWindowControls
+        let shouldShow = shouldShowWindowControls && !Preferences.hideColoredCircles && !(window_?.isWindowlessApp ?? true) && !Preferences.hideThumbnails
         if isShowingWindowControls != shouldShow {
             isShowingWindowControls = shouldShow
             [closeIcon, minimizeIcon, maximizeIcon].forEach { $0.isHidden = !shouldShow }
@@ -92,7 +91,7 @@ class ThumbnailView: NSStackView {
                 highlightOrNot()
             }
         }
-        showOrHideWindowControls()
+        showOrHideWindowControls(isHighlighted && mouseIsHovering)
     }
 
     func highlightOrNot() {

src/ui/main-window/ThumbnailsView.swift

@@ -220,14 +220,19 @@ class ScrollView: NSScrollView {
             if let target = target, target is ThumbnailView {
                 if previousTarget != target {
                     previousTarget?.showOrHideWindowControls(false)
+                    previousTarget?.mouseIsHovering = false
                     previousTarget = target as? ThumbnailView
                 }
-                (target as! ThumbnailView).mouseMoved()
+                let target = target as! ThumbnailView
+                target.mouseMoved()
+                target.mouseIsHovering = true
             } else {
                 previousTarget?.showOrHideWindowControls(false)
+                previousTarget?.mouseIsHovering = false
             }
         } else {
             previousTarget?.showOrHideWindowControls(false)
+            previousTarget?.mouseIsHovering = false
         }
     }