使用NSSegmentedControl。
通过向控件发送setMenu:forSegment:来添加菜单（在IB中连接到menu插座不起作用）。确保与控件连接一个操作（这很重要）。
应该与您描述的完全一样。
- (void)mouseDown:(NSEvent *)theEvent {
[self setHighlighted:YES];
[self setNeedsDisplay:YES];
_menuShown = NO;
_timer = [NSTimer scheduledTimerWithTimeInterval:0.3 target:self selector:@selector(showContextMenu:) userInfo:nil repeats:NO];
[[NSRunLoop currentRunLoop] addTimer:_timer forMode:NSDefaultRunLoopMode];
}
- (void)mouseUp:(NSEvent *)theEvent {
[self setHighlighted:NO];
[self setNeedsDisplay:YES];
[_timer invalidate];
_timer = nil;
if(!_menuShown) {
[NSApp sendAction:[self action] to:[self target] from:self];
}
_menuShown = NO;
}
- (void)showContextMenu:(NSTimer*)timer {
if(!_timer) {
return;
}
_timer = nil;
_menuShown = YES;
NSMenu *theMenu = [[NSMenu alloc] initWithTitle:@"Contextual Menu"];
[[theMenu addItemWithTitle:@"Beep" action:@selector(beep:) keyEquivalent:@""] setTarget:self];
[[theMenu addItemWithTitle:@"Honk" action:@selector(honk:) keyEquivalent:@""] setTarget:self];
[theMenu popUpMenuPositioningItem:nil atLocation:NSMakePoint(self.bounds.size.width-8, self.bounds.size.height-1) inView:self];
NSWindow* window = [self window];
NSEvent* fakeMouseUp = [NSEvent mouseEventWithType:NSLeftMouseUp
location:self.bounds.origin
modifierFlags:0
timestamp:[NSDate timeIntervalSinceReferenceDate]
windowNumber:[window windowNumber]
context:[NSGraphicsContext currentContext]
eventNumber:0
clickCount:1
pressure:0.0];
[window postEvent:fakeMouseUp atStart:YES];
[self setState:NSOnState];
}
我已经在GitHub上发布了一个工作示例。
创建一个NSPopUpButton子类，并覆盖mouseDown/mouseUp事件。
让mouseDown事件在调用super的实现之前延迟片刻，只有当鼠标仍然按下时才调用。
让mouseUp事件将selectedMenuItem设置为nil（因此selectedMenuItemIndex将为-1）再触发按钮的target/action。
唯一的问题是如何处理快速点击，其中一个点击的计时器可能会在鼠标按下某个未来的点击时触发。我选择使用mouseDown事件的一个简单计数器来代替使用NSTimer并使其无效。
以下是我在子类中使用的代码：
// MyClickAndHoldPopUpButton.h
@interface MyClickAndHoldPopUpButton : NSPopUpButton
@end
// MyClickAndHoldPopUpButton.m
@interface MyClickAndHoldPopUpButton ()
@property BOOL mouseIsDown;
@property BOOL menuWasShownForLastMouseDown;
@property int mouseDownUniquenessCounter;
@end
@implementation MyClickAndHoldPopUpButton
// highlight the button immediately but wait a moment before calling the super method (which will show our popup menu) if the mouse comes up
// in that moment, don't tell the super method about the mousedown at all.
- (void)mouseDown:(NSEvent *)theEvent
{
self.mouseIsDown = YES;
self.menuWasShownForLastMouseDown = NO;
self.mouseDownUniquenessCounter++;
int mouseDownUniquenessCounterCopy = self.mouseDownUniquenessCounter;
[self highlight:YES];
float delayInSeconds = [NSEvent doubleClickInterval];
dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC);
dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
if (self.mouseIsDown && mouseDownUniquenessCounterCopy == self.mouseDownUniquenessCounter) {
self.menuWasShownForLastMouseDown = YES;
[super mouseDown:theEvent];
}
});
}
// if the mouse was down for a short enough period to avoid showing a popup menu, fire our target/action with no selected menu item, then
// remove the button highlight.
- (void)mouseUp:(NSEvent *)theEvent
{
self.mouseIsDown = NO;
if (!self.menuWasShownForLastMouseDown) {
[self selectItem:nil];
[self sendAction:self.action to:self.target];
}
[self highlight:NO];
}
@end
delayInSeconds，考虑使用 NSEvent.doubleClickInterval 而不是常量 0.2。这将根据用户的鼠标操作偏好调整延迟时间。对于双击时间短的用户来说，速度更快，延迟更少；对于双击时间长的用户来说，速度更慢，延迟更多。 - Graham Miln虽然有点晚，但这里提供一种不同的方法，也是通过子类化NSButton来实现：
///
/// @copyright © 2018 Vadim Shpakovski. All rights reserved.
///
import AppKit
/// Button with a delayed menu like Safari Go Back & Forward buttons.
public class DelayedMenuButton: NSButton {
/// Click & Hold menu, appears after `NSEvent.doubleClickInterval` seconds.
public var delayedMenu: NSMenu?
}
// MARK: -
extension DelayedMenuButton {
public override func mouseDown(with event: NSEvent) {
// Run default implementation if delayed menu is not assigned
guard delayedMenu != nil, isEnabled else {
super.mouseDown(with: event)
return
}
/// Run the popup menu if the mouse is down during `doubleClickInterval` seconds
let delayedItem = DispatchWorkItem { [weak self] in
self?.showDelayedMenu()
}
DispatchQueue.main.asyncAfter(deadline: .now() + .milliseconds(Int(NSEvent.doubleClickInterval * 1000)), execute: delayedItem)
/// Action will be set to nil if the popup menu runs during `super.mouseDown`
let defaultAction = self.action
// Run standard tracking
super.mouseDown(with: event)
// Restore default action if popup menu assigned it to nil
self.action = defaultAction
// Cancel popup menu once tracking is over
delayedItem.cancel()
}
}
// MARK: - Private API
private extension DelayedMenuButton {
/// Cancels current tracking and runs the popup menu
func showDelayedMenu() {
// Simulate mouse up to stop native tracking
guard
let delayedMenu = delayedMenu, delayedMenu.numberOfItems > 0, let window = window, let location = NSApp.currentEvent?.locationInWindow,
let mouseUp = NSEvent.mouseEvent(
with: .leftMouseUp, location: location, modifierFlags: [], timestamp: Date.timeIntervalSinceReferenceDate,
windowNumber: window.windowNumber, context: NSGraphicsContext.current, eventNumber: 0, clickCount: 1, pressure: 0
)
else {
return
}
// Cancel default action
action = nil
// Show the default menu
delayedMenu.popUp(positioning: nil, at: .init(x: -4, y: bounds.height + 2), in: self)
// Send mouse up when the menu is on screen
window.postEvent(mouseUp, atStart: false)
}
}