Content Privacy flag for Windows and MacOS (#4241)

* feat(options): add ContentProtection bool config to macos and windows options

* feat(darwin): implement ContentProtection for darwin

* feat(windows): implement ContentProtection for windows

* chore(website): add feature to changelog

* feat(examples): add an example showcasing the ContentPrivacy flag

* chore(examples): update readme

* fix(example): format and build

* fix(winc): rename to wda and add version check

* chore(reference): add docs for ContentProtection

* fix(darwin): future-proof setting the sharing type

* fix(example): wording consistency

* chore(examples): remove privatewindow example

---------

Co-authored-by: Lea Anthony <lea.anthony@gmail.com>

v2/internal/frontend/desktop/darwin/Application.h

@@ -17,7 +17,7 @@
 #define WindowStartsMinimised 2
 #define WindowStartsFullscreen 3
 
-WailsContext* Create(const char* title, int width, int height, int frameless, int resizable, int zoomable, int fullscreen, int fullSizeContent, int hideTitleBar, int titlebarAppearsTransparent, int hideTitle, int useToolbar, int hideToolbarSeparator, int webviewIsTransparent, int alwaysOnTop, int hideWindowOnClose, const char *appearance, int windowIsTranslucent, int devtoolsEnabled, int defaultContextMenuEnabled, int windowStartState, int startsHidden, int minWidth, int minHeight, int maxWidth, int maxHeight, bool fraudulentWebsiteWarningEnabled, struct Preferences preferences, int singleInstanceEnabled, const char* singleInstanceUniqueId, bool enableDragAndDrop, bool disableWebViewDragAndDrop);
+WailsContext* Create(const char* title, int width, int height, int frameless, int resizable, int zoomable, int fullscreen, int fullSizeContent, int hideTitleBar, int titlebarAppearsTransparent, int hideTitle, int useToolbar, int hideToolbarSeparator, int webviewIsTransparent, int alwaysOnTop, int hideWindowOnClose, const char *appearance, int windowIsTranslucent, int contentProtection, int devtoolsEnabled, int defaultContextMenuEnabled, int windowStartState, int startsHidden, int minWidth, int minHeight, int maxWidth, int maxHeight, bool fraudulentWebsiteWarningEnabled, struct Preferences preferences, int singleInstanceLockEnabled, const char* singleInstanceUniqueId, bool enableDragAndDrop, bool disableWebViewDragAndDrop);
 void Run(void*, const char* url);
 
 void SetTitle(void* ctx, const char *title);

v2/internal/frontend/desktop/darwin/Application.m

@@ -14,7 +14,7 @@
 #import "WailsMenu.h"
 #import "WailsMenuItem.h"
 
-WailsContext* Create(const char* title, int width, int height, int frameless, int resizable, int zoomable, int fullscreen, int fullSizeContent, int hideTitleBar, int titlebarAppearsTransparent, int hideTitle, int useToolbar, int hideToolbarSeparator, int webviewIsTransparent, int alwaysOnTop, int hideWindowOnClose, const char *appearance, int windowIsTranslucent, int devtoolsEnabled, int defaultContextMenuEnabled, int windowStartState, int startsHidden, int minWidth, int minHeight, int maxWidth, int maxHeight, bool fraudulentWebsiteWarningEnabled, struct Preferences preferences, int singleInstanceLockEnabled, const char* singleInstanceUniqueId, bool enableDragAndDrop, bool disableWebViewDragAndDrop) {
+WailsContext* Create(const char* title, int width, int height, int frameless, int resizable, int zoomable, int fullscreen, int fullSizeContent, int hideTitleBar, int titlebarAppearsTransparent, int hideTitle, int useToolbar, int hideToolbarSeparator, int webviewIsTransparent, int alwaysOnTop, int hideWindowOnClose, const char *appearance, int windowIsTranslucent, int contentProtection, int devtoolsEnabled, int defaultContextMenuEnabled, int windowStartState, int startsHidden, int minWidth, int minHeight, int maxWidth, int maxHeight, bool fraudulentWebsiteWarningEnabled, struct Preferences preferences, int singleInstanceLockEnabled, const char* singleInstanceUniqueId, bool enableDragAndDrop, bool disableWebViewDragAndDrop) {
 
     [NSApplication sharedApplication];
 
@@ -31,6 +31,11 @@ WailsContext* Create(const char* title, int width, int height, int frameless, in
     [result SetTitle:safeInit(title)];
     [result Center];
 
+    if (contentProtection == 1 &&
+        [result.mainWindow respondsToSelector:@selector(setSharingType:)]) {
+        [result.mainWindow setSharingType:NSWindowSharingNone];
+    }
+
     switch( windowStartState ) {
         case WindowStartsMaximised:
             [result.mainWindow zoom:nil];

v2/internal/frontend/desktop/darwin/window.go

@@ -63,7 +63,7 @@ func NewWindow(frontendOptions *options.App, debug bool, devtools bool) *Window
 	singleInstanceEnabled := bool2Cint(frontendOptions.SingleInstanceLock != nil)
 
 	var fullSizeContent, hideTitleBar, zoomable, hideTitle, useToolbar, webviewIsTransparent C.int
-	var titlebarAppearsTransparent, hideToolbarSeparator, windowIsTranslucent C.int
+	var titlebarAppearsTransparent, hideToolbarSeparator, windowIsTranslucent, contentProtection C.int
 	var appearance, title *C.char
 	var preferences C.struct_Preferences
 
@@ -117,12 +117,13 @@ func NewWindow(frontendOptions *options.App, debug bool, devtools bool) *Window
 
 		windowIsTranslucent = bool2Cint(mac.WindowIsTranslucent)
 		webviewIsTransparent = bool2Cint(mac.WebviewIsTransparent)
+		contentProtection = bool2Cint(mac.ContentProtection)
 
 		appearance = c.String(string(mac.Appearance))
 	}
 	var context *C.WailsContext = C.Create(title, width, height, frameless, resizable, zoomable, fullscreen, fullSizeContent,
 		hideTitleBar, titlebarAppearsTransparent, hideTitle, useToolbar, hideToolbarSeparator, webviewIsTransparent,
-		alwaysOnTop, hideWindowOnClose, appearance, windowIsTranslucent, devtoolsEnabled, defaultContextMenuEnabled,
+		alwaysOnTop, hideWindowOnClose, appearance, windowIsTranslucent, contentProtection, devtoolsEnabled, defaultContextMenuEnabled,
 		windowStartState, startsHidden, minWidth, minHeight, maxWidth, maxHeight, enableFraudulentWebsiteWarnings,
 		preferences, singleInstanceEnabled, singleInstanceUniqueId, enableDragAndDrop, disableWebViewDragAndDrop,
 	)

v2/internal/frontend/desktop/windows/winc/controlbase.go

@@ -170,6 +170,14 @@ func (cba *ControlBase) SetTranslucentBackground() {
 	w32.SetWindowCompositionAttribute(cba.hwnd, &data)
 }
 
+func (cba *ControlBase) SetContentProtection(enable bool) {
+	if enable {
+		w32.SetWindowDisplayAffinity(uintptr(cba.hwnd), w32.WDA_EXCLUDEFROMCAPTURE)
+	} else {
+		w32.SetWindowDisplayAffinity(uintptr(cba.hwnd), w32.WDA_NONE)
+	}
+}
+
 func min(a, b int) int {
 	if a < b {
 		return a

v2/internal/frontend/desktop/windows/winc/w32/wda.go

@@ -0,0 +1,47 @@
+//go:build windows
+
+package w32
+
+import (
+	"syscall"
+
+	"github.com/wailsapp/wails/v2/internal/system/operatingsystem"
+)
+
+var user32 = syscall.NewLazyDLL("user32.dll")
+var procSetWindowDisplayAffinity = user32.NewProc("SetWindowDisplayAffinity")
+var windowsVersion, _ = operatingsystem.GetWindowsVersionInfo()
+
+const (
+	WDA_NONE               = 0x00000000
+	WDA_MONITOR            = 0x00000001
+	WDA_EXCLUDEFROMCAPTURE = 0x00000011 // windows 10 2004+
+)
+
+func isWindowsVersionAtLeast(major, minor, build int) bool {
+	if windowsVersion.Major > major {
+		return true
+	}
+	if windowsVersion.Major < major {
+		return false
+	}
+	if windowsVersion.Minor > minor {
+		return true
+	}
+	if windowsVersion.Minor < minor {
+		return false
+	}
+	return windowsVersion.Build >= build
+}
+
+func SetWindowDisplayAffinity(hwnd uintptr, affinity uint32) bool {
+	if affinity == WDA_EXCLUDEFROMCAPTURE && !isWindowsVersionAtLeast(10, 0, 19041) {
+		// for older windows versions, use WDA_MONITOR
+		affinity = WDA_MONITOR
+	}
+	ret, _, _ := procSetWindowDisplayAffinity.Call(
+		hwnd,
+		uintptr(affinity),
+	)
+	return ret != 0
+}

v2/internal/frontend/desktop/windows/window.go

@@ -131,6 +131,10 @@ func NewWindow(parent winc.Controller, appoptions *options.App, versionInfo *ope
 			}
 		}
 
+		if windowsOptions.ContentProtection {
+			w32.SetWindowDisplayAffinity(result.Handle(), w32.WDA_EXCLUDEFROMCAPTURE)
+		}
+
 		if windowsOptions.DisableWindowIcon {
 			result.DisableIcon()
 		}

v2/pkg/options/mac/mac.go

@@ -18,6 +18,7 @@ type AboutInfo struct {
 type Options struct {
 	TitleBar             *TitleBar
 	Appearance           AppearanceType
+	ContentProtection    bool
 	WebviewIsTransparent bool
 	WindowIsTranslucent  bool
 	Preferences          *Preferences

v2/pkg/options/windows/windows.go

@@ -61,6 +61,7 @@ type ThemeSettings struct {
 
 // Options are options specific to Windows
 type Options struct {
+	ContentProtection    bool
 	WebviewIsTransparent bool
 	WindowIsTranslucent  bool
 	DisableWindowIcon    bool