Added support for template icons on macOS

Cherry-picked https://github.com/getlantern/systray/pull/119 with
significant changes to systray_windows.go to support setting icon on
menu items.

example/main.go

@@ -22,7 +22,7 @@ func main() {
 }
 
 func onReady() {
-	systray.SetIcon(icon.Data)
+	systray.SetTemplateIcon(icon.Data, icon.Data)
 	systray.SetTitle("Awesome App")
 	systray.SetTooltip("Lantern")
 	mQuitOrig := systray.AddMenuItem("Quit", "Quit the whole app")
@@ -35,12 +35,15 @@ func onReady() {
 
 	// We can manipulate the systray in other goroutines
 	go func() {
-		systray.SetIcon(icon.Data)
+		systray.SetTemplateIcon(icon.Data, icon.Data)
 		systray.SetTitle("Awesome App")
 		systray.SetTooltip("Pretty awesome棒棒嗒")
 		mChange := systray.AddMenuItem("Change Me", "Change Me")
 		mChecked := systray.AddMenuItem("Unchecked", "Check Me")
 		mEnabled := systray.AddMenuItem("Enabled", "Enabled")
+		// Sets the icon of a menu item. Only available on Mac.
+		mEnabled.SetTemplateIcon(icon.Data, icon.Data)
+
 		systray.AddMenuItem("Ignored", "Ignored")
 		mUrl := systray.AddMenuItem("Open Lantern.org", "my home")
 		mQuit := systray.AddMenuItem("退出", "Quit the whole app")

systray.h

@@ -1,10 +1,12 @@
+#include "stdbool.h"
+
 extern void systray_ready();
 extern void systray_on_exit();
 extern void systray_menu_item_selected(int menu_id);
 int nativeLoop(void);
 
-void setIcon(const char* iconBytes, int length);
-void setMenuItemIcon(const char* iconBytes, int length, int menuId);
+void setIcon(const char* iconBytes, int length, bool template);
+void setMenuItemIcon(const char* iconBytes, int length, int menuId, bool template);
 void setTitle(char* title);
 void setTooltip(char* tooltip);
 void add_or_update_menu_item(int menuId, char* title, char* tooltip, short disabled, short checked);

systray_darwin.go

@@ -0,0 +1,37 @@
+package systray
+
+/*
+#cgo darwin CFLAGS: -DDARWIN -x objective-c -fobjc-arc
+#cgo darwin LDFLAGS: -framework Cocoa -framework WebKit
+
+#include "systray.h"
+*/
+import "C"
+
+import (
+	"unsafe"
+)
+
+// SetTemplateIcon sets the systray icon as a template icon (on Mac), falling back
+// to a regular icon on other platforms.
+// templateIconBytes and regularIconBytes should be the content of .ico for windows and
+// .ico/.jpg/.png for other platforms.
+func SetTemplateIcon(templateIconBytes []byte, regularIconBytes []byte) {
+	cstr := (*C.char)(unsafe.Pointer(&templateIconBytes[0]))
+	C.setIcon(cstr, (C.int)(len(templateIconBytes)), true)
+}
+
+// SetIcon sets the icon of a menu item. Only works on macOS and Windows.
+// iconBytes should be the content of .ico/.jpg/.png
+func (item *MenuItem) SetIcon(iconBytes []byte) {
+	SetTemplateIcon(iconBytes, iconBytes)
+}
+
+// SetTemplateIcon sets the icon of a menu item as a template icon (on macOS). On Windows, it
+// falls back to the regular icon bytes and on Linux it does nothing.
+// templateIconBytes and regularIconBytes should be the content of .ico for windows and
+// .ico/.jpg/.png for other platforms.
+func (item *MenuItem) SetTemplateIcon(templateIconBytes []byte, regularIconBytes []byte) {
+	cstr := (*C.char)(unsafe.Pointer(&templateIconBytes[0]))
+	C.setMenuItemIcon(cstr, (C.int)(len(templateIconBytes)), C.int(item.id), true)
+}

systray_darwin.m

@@ -196,18 +196,19 @@ void runInMainThread(SEL method, id object) {
                   waitUntilDone: YES];
 }
 
-void setIcon(const char* iconBytes, int length) {
+void setIcon(const char* iconBytes, int length, bool template) {
   NSData* buffer = [NSData dataWithBytes: iconBytes length:length];
   NSImage *image = [[NSImage alloc] initWithData:buffer];
   [image setSize:NSMakeSize(16, 16)];
+  image.template = template;
   runInMainThread(@selector(setIcon:), (id)image);
 }
 
-void setMenuItemIcon(const char* iconBytes, int length, int menuId) {
+void setMenuItemIcon(const char* iconBytes, int length, int menuId, bool template) {
   NSData* buffer = [NSData dataWithBytes: iconBytes length:length];
   NSImage *image = [[NSImage alloc] initWithData:buffer];
   [image setSize:NSMakeSize(16, 16)];
-
+  image.template = template;
   NSNumber *mId = [NSNumber numberWithInt:menuId];
   runInMainThread(@selector(setMenuItemIcon:), @[image, (id)mId]);
 }

systray_linux.c

@@ -167,7 +167,7 @@ gboolean do_quit(gpointer data) {
 	return FALSE;
 }
 
-void setIcon(const char* iconBytes, int length) {
+void setIcon(const char* iconBytes, int length, bool template) {
 	GBytes* bytes = g_bytes_new_static(iconBytes, length);
 	g_idle_add(do_set_icon, bytes);
 }
@@ -181,7 +181,7 @@ void setTooltip(char* ctooltip) {
 	free(ctooltip);
 }
 
-void setMenuItemIcon(const char* iconBytes, int length, int menuId) {
+void setMenuItemIcon(const char* iconBytes, int length, int menuId, bool template) {
 }
 
 void add_or_update_menu_item(int menu_id, char* title, char* tooltip, short disabled, short checked) {

systray_linux.go

@@ -0,0 +1,29 @@
+package systray
+
+/*
+#cgo darwin CFLAGS: -DDARWIN -x objective-c -fobjc-arc
+#cgo darwin LDFLAGS: -framework Cocoa -framework WebKit
+
+#include "systray.h"
+*/
+import "C"
+
+// SetTemplateIcon sets the systray icon as a template icon (on macOS), falling back
+// to a regular icon on other platforms.
+// templateIconBytes and iconBytes should be the content of .ico for windows and
+// .ico/.jpg/.png for other platforms.
+func SetTemplateIcon(templateIconBytes []byte, regularIconBytes []byte) {
+	SetIcon(regularIconBytes)
+}
+
+// SetIcon sets the icon of a menu item. Only works on macOS and Windows.
+// iconBytes should be the content of .ico/.jpg/.png
+func (item *MenuItem) SetIcon(iconBytes []byte) {
+}
+
+// SetTemplateIcon sets the icon of a menu item as a template icon (on macOS). On Windows, it
+// falls back to the regular icon bytes and on Linux it does nothing.
+// templateIconBytes and regularIconBytes should be the content of .ico for windows and
+// .ico/.jpg/.png for other platforms.
+func (item *MenuItem) SetTemplateIcon(templateIconBytes []byte, regularIconBytes []byte) {
+}

systray_nonwindows.go

@@ -28,7 +28,7 @@ func quit() {
 // for other platforms.
 func SetIcon(iconBytes []byte) {
 	cstr := (*C.char)(unsafe.Pointer(&iconBytes[0]))
-	C.setIcon(cstr, (C.int)(len(iconBytes)))
+	C.setIcon(cstr, (C.int)(len(iconBytes)), false)
 }
 
 // SetTitle sets the systray title, only available on Mac.
@@ -60,13 +60,6 @@ func addOrUpdateMenuItem(item *MenuItem) {
 	)
 }
 
-// SetIcon sets the icon of a menu item. Only available on Mac.
-// iconBytes should be the content of .ico/.jpg/.png
-func (item *MenuItem) SetIcon(iconBytes []byte) {
-	cstr := (*C.char)(unsafe.Pointer(&iconBytes[0]))
-	C.setMenuItemIcon(cstr, (C.int)(len(iconBytes)), C.int(item.id))
-}
-
 func addSeparator(id int32) {
 	C.add_separator(C.int(id))
 }

systray_windows.go

@@ -150,7 +150,7 @@ type menuItemInfo struct {
 	ItemData                    uintptr
 	TypeData                    *uint16
 	Cch                         uint32
-	Item                        windows.Handle
+	BMPItem                     windows.Handle
 }
 
 // The POINT structure defines the x- and y- coordinates of a point.
@@ -178,34 +178,13 @@ type winTray struct {
 }
 
 // Loads an image from file and shows it in tray.
-// LoadImage: https://msdn.microsoft.com/en-us/library/windows/desktop/ms648045(v=vs.85).aspx
 // Shell_NotifyIcon: https://msdn.microsoft.com/en-us/library/windows/desktop/bb762159(v=vs.85).aspx
 func (t *winTray) setIcon(src string) error {
-	const IMAGE_ICON = 1               // Loads an icon
-	const LR_LOADFROMFILE = 0x00000010 // Loads the stand-alone image from the file
-	const LR_DEFAULTSIZE = 0x00000040  // Loads default-size icon for windows(SM_CXICON x SM_CYICON) if cx, cy are set to zero
 	const NIF_ICON = 0x00000002
 
-	// Save and reuse handles of loaded images
-	h, ok := t.loadedImages[src]
-	if !ok {
-		srcPtr, err := windows.UTF16PtrFromString(src)
-		if err != nil {
-			return err
-		}
-		res, _, err := pLoadImage.Call(
-			0,
-			uintptr(unsafe.Pointer(srcPtr)),
-			IMAGE_ICON,
-			0,
-			0,
-			LR_LOADFROMFILE|LR_DEFAULTSIZE,
-		)
-		if res == 0 {
-			return err
-		}
-		h = windows.Handle(res)
-		t.loadedImages[src] = h
+	h, err := t.loadIconFrom(src)
+	if err != nil {
+		return err
 	}
 
 	t.nid.Icon = h
@@ -433,13 +412,14 @@ func (t *winTray) createMenu() error {
 	return nil
 }
 
-func (t *winTray) addOrUpdateMenuItem(menuId int32, title string, disabled, checked bool) error {
+func (t *winTray) addOrUpdateMenuItem(menuId int32, title string, disabled, checked bool, hIcon windows.Handle) error {
 	// https://msdn.microsoft.com/en-us/library/windows/desktop/ms647578(v=vs.85).aspx
 	const (
 		MIIM_FTYPE  = 0x00000100
 		MIIM_STRING = 0x00000040
 		MIIM_ID     = 0x00000002
 		MIIM_STATE  = 0x00000001
+		MIIM_BITMAP = 0x00000080
 	)
 	const MFT_STRING = 0x00000000
 	const (
@@ -464,6 +444,10 @@ func (t *winTray) addOrUpdateMenuItem(menuId int32, title string, disabled, chec
 	if checked {
 		mi.State |= MFS_CHECKED
 	}
+	if hIcon > 0 {
+		mi.Mask |= MIIM_BITMAP
+		mi.BMPItem = hIcon
+	}
 	mi.Size = uint32(unsafe.Sizeof(mi))
 
 	// We set the menu item info based on the menuID
@@ -594,6 +578,37 @@ func (t *winTray) getVisibleItemIndex(val int32) int {
 	return -1
 }
 
+// Loads an image from file to be shown in tray or menu item.
+// LoadImage: https://msdn.microsoft.com/en-us/library/windows/desktop/ms648045(v=vs.85).aspx
+func (t *winTray) loadIconFrom(src string) (windows.Handle, error) {
+	const IMAGE_ICON = 1               // Loads an icon
+	const LR_LOADFROMFILE = 0x00000010 // Loads the stand-alone image from the file
+	const LR_DEFAULTSIZE = 0x00000040  // Loads default-size icon for windows(SM_CXICON x SM_CYICON) if cx, cy are set to zero
+
+	// Save and reuse handles of loaded images
+	h, ok := t.loadedImages[src]
+	if !ok {
+		srcPtr, err := windows.UTF16PtrFromString(src)
+		if err != nil {
+			return 0, err
+		}
+		res, _, err := pLoadImage.Call(
+			0,
+			uintptr(unsafe.Pointer(srcPtr)),
+			IMAGE_ICON,
+			0,
+			0,
+			LR_LOADFROMFILE|LR_DEFAULTSIZE,
+		)
+		if res == 0 {
+			return 0, err
+		}
+		h = windows.Handle(res)
+		t.loadedImages[src] = h
+	}
+	return h, nil
+}
+
 func nativeLoop() {
 	if err := wt.initInstance(); err != nil {
 		log.Errorf("Unable to init instance: %v", err)
@@ -652,35 +667,67 @@ func quit() {
 	)
 }
 
-// SetIcon sets the systray icon.
-// iconBytes should be the content of .ico for windows and .ico/.jpg/.png
-// for other platforms.
-func SetIcon(iconBytes []byte) {
+func iconBytesToFilePath(iconBytes []byte) (string, error) {
 	bh := md5.Sum(iconBytes)
 	dataHash := hex.EncodeToString(bh[:])
 	iconFilePath := filepath.Join(os.TempDir(), "systray_temp_icon_"+dataHash)
 
 	if _, err := os.Stat(iconFilePath); os.IsNotExist(err) {
 		if err := ioutil.WriteFile(iconFilePath, iconBytes, 0644); err != nil {
-			log.Errorf("Unable to write icon data to temp file: %v", err)
-			return
+			return "", err
 		}
 	}
+	return iconFilePath, nil
+}
 
+// SetIcon sets the systray icon.
+// iconBytes should be the content of .ico for windows and .ico/.jpg/.png
+// for other platforms.
+func SetIcon(iconBytes []byte) {
+	iconFilePath, err := iconBytesToFilePath(iconBytes)
+	if err != nil {
+		log.Errorf("Unable to write icon data to temp file: %v", err)
+		return
+	}
 	if err := wt.setIcon(iconFilePath); err != nil {
 		log.Errorf("Unable to set icon: %v", err)
 		return
 	}
 }
 
+// SetTemplateIcon sets the systray icon as a template icon (on macOS), falling back
+// to a regular icon on other platforms.
+// templateIconBytes and iconBytes should be the content of .ico for windows and
+// .ico/.jpg/.png for other platforms.
+func SetTemplateIcon(templateIconBytes []byte, regularIconBytes []byte) {
+	SetIcon(regularIconBytes)
+}
+
 // SetTitle sets the systray title, only available on Mac.
 func SetTitle(title string) {
 	// do nothing
 }
 
-// SetIcon sets the icon of a menu item. Only available on Mac.
+// SetIcon sets the icon of a menu item. Only works on macOS and Windows.
+// iconBytes should be the content of .ico/.jpg/.png
 func (item *MenuItem) SetIcon(iconBytes []byte) {
-	// do nothing
+	iconFilePath, err := iconBytesToFilePath(iconBytes)
+	if err != nil {
+		log.Errorf("Unable to write icon data to temp file: %v", err)
+		return
+	}
+
+	h, err := wt.loadIconFrom(iconFilePath)
+	if err != nil {
+		log.Errorf("Unable to load icon from temp file: %v", err)
+		return
+	}
+
+	err = wt.addOrUpdateMenuItem(item.id, item.title, item.disabled, item.checked, h)
+	if err != nil {
+		log.Errorf("Unable to addOrUpdateMenuItem: %v", err)
+		return
+	}
 }
 
 // SetTooltip sets the systray tooltip to display on mouse hover of the tray icon,
@@ -693,13 +740,21 @@ func SetTooltip(tooltip string) {
 }
 
 func addOrUpdateMenuItem(item *MenuItem) {
-	err := wt.addOrUpdateMenuItem(item.id, item.title, item.disabled, item.checked)
+	err := wt.addOrUpdateMenuItem(item.id, item.title, item.disabled, item.checked, 0)
 	if err != nil {
 		log.Errorf("Unable to addOrUpdateMenuItem: %v", err)
 		return
 	}
 }
 
+// SetTemplateIcon sets the icon of a menu item as a template icon (on macOS). On Windows, it
+// falls back to the regular icon bytes and on Linux it does nothing.
+// templateIconBytes and regularIconBytes should be the content of .ico for windows and
+// .ico/.jpg/.png for other platforms.
+func (item *MenuItem) SetTemplateIcon(templateIconBytes []byte, regularIconBytes []byte) {
+	item.SetIcon(regularIconBytes)
+}
+
 func addSeparator(id int32) {
 	err := wt.addSeparatorMenuItem(id)
 	if err != nil {