Add error-returning mouse click helpers (ClickE)

mouse/mouse_c.h

@@ -156,20 +156,29 @@ MMPointInt32 location() {
 }
 
 /* Press down a button, or release it. */
-void toggleMouse(bool down, MMMouseButton button) {
+int toggleMouseErr(bool down, MMMouseButton button) {
 	#if defined(IS_MACOSX)
 		const CGPoint currentPos = CGPointFromMMPointInt32(location());
 		const CGEventType mouseType = MMMouseToCGEventType(down, button);
 		CGEventSourceRef source = CGEventSourceCreate(kCGEventSourceStateHIDSystemState);
 		CGEventRef event = CGEventCreateMouseEvent(source, mouseType, currentPos, (CGMouseButton)button);
 
+		if (event == NULL) {
+			CFRelease(source);
+			return (int)kCGErrorCannotComplete;
+		}
+
 		CGEventPost(kCGHIDEventTap, event);
 		CFRelease(event);
 		CFRelease(source);
+
+		return 0;
 	#elif defined(USE_X11)
 		Display *display = XGetMainDisplay();
-		XTestFakeButtonEvent(display, button, down ? True : False, CurrentTime);
+		Status status = XTestFakeButtonEvent(display, button, down ? True : False, CurrentTime);
 		XSync(display, false);
+
+		return status ? 0 : 1;
 	#elif defined(IS_WINDOWS)
 		// mouse_event(MMMouseToMEventF(down, button), 0, 0, 0, 0);
 		INPUT mouseInput;
@@ -181,18 +190,31 @@ void toggleMouse(bool down, MMMouseButton button) {
 		mouseInput.mi.time = 0;
 		mouseInput.mi.dwExtraInfo = 0;
 		mouseInput.mi.mouseData = 0;
-		SendInput(1, &mouseInput, sizeof(mouseInput));
+		UINT sent = SendInput(1, &mouseInput, sizeof(mouseInput));
+		return sent == 1 ? 0 : (int)GetLastError();
 	#endif
 }
 
-void clickMouse(MMMouseButton button){
-	toggleMouse(true, button);
+void toggleMouse(bool down, MMMouseButton button) {
+	toggleMouseErr(down, button);
+}
+
+int clickMouseErr(MMMouseButton button){
+	int err = toggleMouseErr(true, button);
+	if (err != 0) {
+		return err;
+	}
+
 	microsleep(5.0);
-	toggleMouse(false, button);
+
+	return toggleMouseErr(false, button);
 }
 
-/* Special function for sending double clicks, needed for MacOS. */
-void doubleClick(MMMouseButton button){
+void clickMouse(MMMouseButton button){
+	clickMouseErr(button);
+}
+
+int doubleClickErr(MMMouseButton button){
 	#if defined(IS_MACOSX)
 		/* Double click for Mac. */
 		const CGPoint currentPos = CGPointFromMMPointInt32(location());
@@ -202,6 +224,11 @@ void doubleClick(MMMouseButton button){
 		CGEventSourceRef source = CGEventSourceCreate(kCGEventSourceStateHIDSystemState);
 		CGEventRef event = CGEventCreateMouseEvent(source, mouseTypeDown, currentPos, kCGMouseButtonLeft);
 
+		if (event == NULL) {
+			CFRelease(source);
+			return (int)kCGErrorCannotComplete;
+		}
+
 		/* Set event to double click. */
 		CGEventSetIntegerValueField(event, kCGMouseEventClickState, 2);
 		CGEventPost(kCGHIDEventTap, event);
@@ -211,14 +238,26 @@ void doubleClick(MMMouseButton button){
 
 		CFRelease(event);
 		CFRelease(source);
+
+		return 0;
 	#else
 		/* Double click for everything else. */
-		clickMouse(button);
+		int err = clickMouseErr(button);
+		if (err != 0) {
+			return err;
+		}
+
 		microsleep(200);
-		clickMouse(button);
+
+		return clickMouseErr(button);
 	#endif
 }
 
+/* Special function for sending double clicks, needed for MacOS. */
+void doubleClick(MMMouseButton button){
+	doubleClickErr(button);
+}
+
 /* Function used to scroll the screen in the required direction. */
 void scrollMouseXY(int x, int y) {
 	#if defined(IS_WINDOWS)

robotgo.go

@@ -52,8 +52,10 @@ import "C"
 
 import (
 	"errors"
+	"fmt"
 	"image"
 	"runtime"
+	"syscall"
 	"time"
 	"unsafe"
 
@@ -505,6 +507,24 @@ func CheckMouse(btn string) C.MMMouseButton {
 	return C.LEFT_BUTTON
 }
 
+// MouseButtonString converts a C.MMMouseButton to a readable name.
+func MouseButtonString(btn C.MMMouseButton) string {
+	m1 := map[C.MMMouseButton]string{
+		C.LEFT_BUTTON:   "left",
+		C.CENTER_BUTTON: "center",
+		C.RIGHT_BUTTON:  "right",
+		C.WheelDown:     "wheelDown",
+		C.WheelUp:       "wheelUp",
+		C.WheelLeft:     "wheelLeft",
+		C.WheelRight:    "wheelRight",
+	}
+	if v, ok := m1[btn]; ok {
+		return v
+	}
+
+	return fmt.Sprintf("button%d", btn)
+}
+
 // MoveScale calculate the os scale factor x, y
 func MoveScale(x, y int, displayId ...int) (int, int) {
 	if Scale || runtime.GOOS == "windows" {
@@ -671,6 +691,97 @@ func Click(args ...interface{}) {
 	MilliSleep(MouseSleep)
 }
 
+// ClickE click the mouse button and return error
+//
+// robotgo.ClickE(button string, double bool)
+//
+// Examples:
+//
+//	err := robotgo.ClickE() // default is left button
+//	err := robotgo.ClickE("right")
+func ClickE(args ...interface{}) error {
+	var (
+		button C.MMMouseButton = C.LEFT_BUTTON
+		double bool
+	)
+
+	if len(args) > 0 {
+		btn, ok := args[0].(string)
+		if !ok {
+			return errors.New("first argument must be a button string")
+		}
+		button = CheckMouse(btn)
+	}
+
+	if len(args) > 1 {
+		dbl, ok := args[1].(bool)
+		if !ok {
+			return errors.New("second argument must be a bool indicating double click")
+		}
+		double = dbl
+	}
+
+	defer MilliSleep(MouseSleep)
+
+	if !double {
+		if code := C.toggleMouseErr(true, button); code != 0 {
+			return formatClickError(int(code), button, "down", false)
+		}
+
+		// match clickMouse timing
+		C.microsleep(C.double(5.0))
+
+		if code := C.toggleMouseErr(false, button); code != 0 {
+			return formatClickError(int(code), button, "up", false)
+		}
+	} else {
+		if code := C.doubleClickErr(button); code != 0 {
+			return formatClickError(int(code), button, "double", true)
+		}
+	}
+
+	return nil
+}
+
+func formatClickError(code int, button C.MMMouseButton, stage string, double bool) error {
+	btnName := MouseButtonString(button)
+	detail := ""
+
+	switch runtime.GOOS {
+	case "windows":
+		if code != 0 {
+			detail = syscall.Errno(code).Error()
+		}
+	case "darwin":
+		cgErrors := map[int]string{
+			0:    "kCGErrorSuccess",
+			1000: "kCGErrorFailure",
+			1001: "kCGErrorIllegalArgument",
+			1002: "kCGErrorInvalidConnection",
+			1003: "kCGErrorInvalidContext",
+			1004: "kCGErrorCannotComplete",
+			1005: "kCGErrorNotImplemented",
+			1006: "kCGErrorRangeCheck",
+			1007: "kCGErrorTypeCheck",
+			1008: "kCGErrorNoCurrentPoint",
+			1010: "kCGErrorInvalidOperation",
+		}
+		if v, ok := cgErrors[code]; ok {
+			detail = v
+		}
+	default:
+		if code == 1 {
+			detail = "XTestFakeButtonEvent returned false"
+		}
+	}
+
+	if detail != "" {
+		return fmt.Errorf("click %s failed (%s, double=%v): %s (code=%d)", stage, btnName, double, detail, code)
+	}
+
+	return fmt.Errorf("click %s failed (%s, double=%v), code=%d", stage, btnName, double, code)
+}
+
 // MoveClick move and click the mouse
 //
 // robotgo.MoveClick(x, y int, button string, double bool)