macos: reorganize, rename, put files in groups

macos/Sources/Helpers/FullScreenHandler.swift

@@ -0,0 +1,103 @@
+import SwiftUI
+
+class FullScreenHandler {
+    var previousTabGroup: NSWindowTabGroup?
+    var previousTabGroupIndex: Int?
+    var previousContentFrame: NSRect?
+    var previousStyleMask: NSWindow.StyleMask?
+    var isInFullscreen: Bool = false
+    
+    // We keep track of whether we entered non-native fullscreen in case
+    // a user goes to fullscreen, changes the config to disable non-native fullscreen
+    // and then wants to toggle it off
+    var isInNonNativeFullscreen: Bool = false
+    
+    func toggleFullscreen(window: NSWindow, nonNativeFullscreen: Bool) {
+        if isInFullscreen {
+            if nonNativeFullscreen || isInNonNativeFullscreen {
+                leaveFullscreen(window: window)
+                isInNonNativeFullscreen = false
+            } else {
+                window.toggleFullScreen(nil)
+            }
+            isInFullscreen = false
+        } else {
+            if nonNativeFullscreen {
+                enterFullscreen(window: window)
+                isInNonNativeFullscreen = true
+            } else {
+                window.toggleFullScreen(nil)
+            }
+            isInFullscreen = true
+        }
+    }
+    
+    func enterFullscreen(window: NSWindow) {
+        guard let screen = window.screen else { return }
+        guard let contentView = window.contentView else { return }
+        
+        previousTabGroup = window.tabGroup
+        previousTabGroupIndex = window.tabGroup?.windows.firstIndex(of: window)
+        
+        // Save previous style mask
+        previousStyleMask = window.styleMask
+        // Save previous contentViewFrame and screen
+        previousContentFrame = window.convertToScreen(contentView.frame)
+        
+        // Change presentation style to hide menu bar and dock
+        NSApp.presentationOptions = [.autoHideMenuBar, .autoHideDock]
+        // Turn it into borderless window
+        window.styleMask.insert(.borderless)
+        // This is important: it gives us the full screen, including the
+        // notch area on MacBooks.
+        window.styleMask.remove(.titled)
+        
+        // Set frame to screen size
+        window.setFrame(screen.frame, display: true)
+        
+        // Focus window
+        window.makeKeyAndOrderFront(nil)
+    }
+    
+    
+    func leaveFullscreen(window: NSWindow) {
+        guard let previousFrame = previousContentFrame else { return }
+        guard let previousStyleMask = previousStyleMask else { return }
+        
+        // Restore previous style
+        window.styleMask = previousStyleMask
+        
+        // Restore previous presentation options
+        NSApp.presentationOptions = []
+        
+        // Restore frame
+        window.setFrame(window.frameRect(forContentRect: previousFrame), display: true)
+        
+        // If the window was previously in a tab group that isn't empty now, we re-add it
+        if let group = previousTabGroup, let tabIndex = previousTabGroupIndex, !group.windows.isEmpty {
+            var tabWindow: NSWindow?
+            var order: NSWindow.OrderingMode = .below
+            
+            // Index of the window before `window`
+            let tabIndexBefore = tabIndex-1
+            if tabIndexBefore < 0 {
+                // If we were the first tab, we add the window *before* (.below) the first one.
+                tabWindow = group.windows.first
+            } else if tabIndexBefore < group.windows.count {
+                // If we weren't the first tab in the group, we add our window after
+                // the tab that was before it.
+                tabWindow = group.windows[tabIndexBefore]
+                order = .above
+            } else {
+                // If index is after group, add it after last window
+                tabWindow = group.windows.last
+            }
+            
+            // Add the window
+            tabWindow?.addTabbedWindow(window, ordered: order)
+        }
+        
+        // Focus window
+        window.makeKeyAndOrderFront(nil)
+    }
+}