NSButton延迟NSMenu - Objective-C/Cocoa

Question

我想创建一个NSButton在单击时发送动作的动作,但是当按下它1或2秒时它会显示一个NSMenu.这里的问题与这个问题完全相同,但由于答案没有解决我的问题,我决定再问一次.

例如,转到Finder,打开一个新窗口,浏览一些文件夹,然后单击后退按钮:您转到上一个文件夹.现在单击并按住后退按钮:显示一个菜单.我不知道如何做到这一点NSPopUpButton.

Answer 1

使用NSSegmentedControl.

通过发送setMenu:forSegment:到控件添加菜单(将任何内容连接到menuIB中的插座将不起作用).有一个动作连接到控件(这很重要).

应该完全按照你的描述工作.

Answer 2

创建一个子类NSPopUpButton并覆盖mouseDown/ mouseUpevents.

mouseDown在调用super实现之前将事件延迟片刻,并且仅在鼠标仍处于按下状态时才会延迟.

有mouseUp事件设置selectedMenuItem到nil(并因此selectedMenuItemIndex将-1发射按钮的前)target/ action.

唯一的另一个问题是处理快速点击,其中一次点击的计时器可能会在鼠标停止以供将来点击时触发.NSTimer我没有使用和使其无效,而是选择了一个简单的mouseDown事件计数器,并在计数器发生变化时进行纾困.

这是我在我的子类中使用的代码:

// 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

Answer 3

如果仍然有人需要它，这是我基于简单NSButton而不是分段控件的解决方案。

子类化NSButton并实现一个自定义mouseDown，该自定义在当前运行循环内启动计时器。在中mouseUp，检查计时器是否未启动。在这种情况下，请取消它并执行默认操作。

这是一种非常简单的方法，可与您可以在IB中使用的任何NSButton一起使用。

代码如下：

- (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。