Add CustomButton which does not handle mouse clicks for you

custombutton.go

@@ -0,0 +1,52 @@
+package gocoa
+
+// #cgo CFLAGS: -x objective-c
+// #cgo LDFLAGS: -framework Cocoa
+// #import "window.h"
+// #import "custombutton.h"
+// #include <stdlib.h>
+import "C"
+import "image"
+
+// Button represents a button control that can trigger actions.
+type CustomButton struct {
+	ptr      C.ButtonPtr
+	callback func(x, y int, secondary bool)
+}
+
+var customButtons []*CustomButton
+
+//export onCustomButtonClicked
+func onCustomButtonClicked(id C.int, x C.int, y C.int, secondary C.bool) {
+	buttonID := int(id)
+	if buttonID < len(buttons) && customButtons[buttonID].callback != nil {
+		customButtons[buttonID].callback(int(x), int(y), bool(secondary))
+	}
+}
+
+func NewCustomButton(x int, y int, width int, height int) *CustomButton {
+	buttonID := len(customButtons)
+	ptr := C.CustomButton_New(C.int(buttonID), C.int(x), C.int(y), C.int(width), C.int(height))
+	btn := &CustomButton{ptr: ptr}
+	customButtons = append(customButtons, btn)
+	return btn
+}
+
+func (c *CustomButton) OnClick(fn func(x, y int, secondary bool)) {
+	c.callback = fn
+}
+
+func (c *CustomButton) Remove() {
+	C.Button_Remove(c.ptr)
+}
+
+func (c *CustomButton) SetImage(img *image.RGBA) {
+	bytes := C.CBytes(img.Pix)
+	nsImage := C.Image_NewWithRGBA(C.int(img.Bounds().Dx()), C.int(img.Bounds().Dy()), (*C.uchar)(bytes))
+	C.Button_SetImage(c.ptr, nsImage)
+	C.free(bytes)
+}
+
+func (w *Window) AddCustomButton(c *CustomButton) {
+	C.Window_AddButton(w.winPtr, c.ptr)
+}

custombutton.h

@@ -0,0 +1,11 @@
+#import "button.h"
+#import "image.h"
+
+@interface CustomButton : NSButton {
+}
+@property(assign) int goButtonID;
+- (void)mouseDown:(NSEvent *)theEvent;
+@end
+
+ButtonPtr CustomButton_New(int goButtonID, int x, int y, int w, int h);
+void Window_AddCustomButton(void *wndPtr, ButtonPtr btnPtr);

custombutton.m

@@ -0,0 +1,27 @@
+#include "_cgo_export.h"
+#import "button.h"
+
+@implementation CustomButton
+- (void)mouseDown:(NSEvent *)theEvent {
+  NSPoint p = [self convertPoint:theEvent.locationInWindow fromView:nil];
+  onCustomButtonClicked([self goButtonID], p.x, p.y,
+                        theEvent.buttonNumber != 1);
+}
+@end
+
+ButtonPtr CustomButton_New(int goButtonID, int x, int y, int w, int h) {
+  CustomButton *nsButton =
+      [[[CustomButton alloc] initWithFrame:NSMakeRect(x, y, w, h)] autorelease];
+
+  [nsButton setGoButtonID:goButtonID];
+  [nsButton setButtonType:NSButtonTypeMomentaryLight];
+  [nsButton setBezelStyle:NSBezelStyleRounded];
+
+  return (ButtonPtr)nsButton;
+}
+
+void Window_AddCustomButton(void *wndPtr, ButtonPtr btnPtr) {
+  CustomButton *button = (CustomButton *)btnPtr;
+  NSWindow *window = (NSWindow *)wndPtr;
+  [[window contentView] addSubview:button];
+}