如何检测NSTextField何时具有焦点或者是否已选择cocoa的内容

Question

我有一个的NSTextField的NSTableCellView里面,我想它告诉我的时候,我的NSTextField已经得到了禁用几个按钮的焦点事件,我发现这个方法:

-(void)controlTextDidBeginEditing:(NSNotification *)obj{
    NSTextField *textField  = (NSTextField *)[obj object];

    if (textField != _nombreDelPaqueteTextField) {
        [_nuevaCuentaActivoButton   setEnabled:FALSE];
        [_nuevaCuentaPasivoButton   setEnabled:FALSE];
        [_nuevaCuentaIngresosButton setEnabled:FALSE];
        [_nuevaCuentaEgresosButton  setEnabled:FALSE];
    }
}

但它会在我的文本字段开始编辑时触发,因为这样说,我希望在我关注textField时禁用按钮,而不是在我已经开始键入时

---

编辑:要根据Joshua Nozzi收到的帮助我的代码,它仍然无法正常工作

MyNSTextField.h

#import <Cocoa/Cocoa.h>
@class MyNSTextField;

@protocol MyNSTextFieldDelegate

@optional -(BOOL)textFieldDidResignFirstResponder:(NSTextField *)sender;
@optional -(BOOL)textFieldDidBecomeFirstResponder:(NSTextField *)sender;

@end

@interface MyNSTextField : NSTextField

@property (strong, nonatomic)           id <MyNSTextFieldDelegate> cellView;

@end

MyNSTextField.m

#import "MyNSTextField.h"

@implementation MyNSTextField

- (BOOL)becomeFirstResponder
{
    BOOL status = [super becomeFirstResponder];
    if (status)

        [self.cellView textFieldDidBecomeFirstResponder:self];
    return status;
}

- (BOOL)resignFirstResponder
{
    BOOL status = [super resignFirstResponder];
    if (status)
        [self.cellView textFieldDidResignFirstResponder:self];
    return status;
}

@end

在我的viewcontroller EdicionDeCuentasWC.m上

#import "MyNSTextField.h"


@interface EdicionDeCuentasWC ()<NSTableViewDataSource, NSTableViewDelegate, NSControlTextEditingDelegate, NSPopoverDelegate, MyNSTextFieldDelegate>
@end


@implementation EdicionDeCuentasWC
#pragma mark MyNSTextFieldDelegate
-(BOOL)textFieldDidBecomeFirstResponder:(NSTextField *)sender{
    NSLog(@"textFieldDidBecomeFirstResponder");
    return TRUE;
}

-(BOOL)textFieldDidResignFirstResponder:(NSTextField *)sender{
    NSLog(@"textFieldDidResignFirstResponder");
    return TRUE;
}
#pragma mark --
@end

在可视化编辑器中说,已经将我的所有NSTextFields更改为MyNSTextField类并将委托设置为我的文件所有者(EdicionDeCuentasWC)

Answer 1

我想我搞定了。我试图子类化NSTextFiled来覆盖becomeFirstResponder()and resignFirstResponder()，但是一旦我点击它，becomeFirstResponder()就会被调用并resignFirstResponder()在之后被调用。嗯？但是搜索字段看起来仍在编辑中，焦点仍在它上面。

我发现，当您单击搜索字段时，搜索字段将成为第一响应者，但NSText稍后会准备好，并且焦点将移至NSText.

我发现当NSText准备好时，它被设置为self.currentEditor(). 问题是 whenbecomeFirstResponder()的调用，self.currentEditor()还没有设置。所以becomeFirstResponder()不是检测它的焦点的方法。

另一方面，当焦点移到 时NSText，resignFirstResponder()将调用文本字段，您知道吗？self.currentEditor()已设置。所以，现在是告诉它的代表该文本字段获得焦点的时刻。

然后接下来，如何检测搜索字段何时失去焦点。再次，它是关于NSText. 然后，您需要监听NSText诸如 的委托方法textDidEndEditing()，并确保让它是超类来处理该方法并查看是否self.currentEditor()无效。如果是这种情况，则NSText失去焦点并告诉文本字段的委托。

我提供了一个代码，实际上是NSSearchField子类来做同样的事情。同样的原则也应该适用NSTextField。

protocol ZSearchFieldDelegate: NSTextFieldDelegate {
    func searchFieldDidBecomeFirstResponder(textField: ZSearchField)
    func searchFieldDidResignFirstResponder(textField: ZSearchField)
}


class ZSearchField: NSSearchField, NSTextDelegate {

    var expectingCurrentEditor: Bool = false

    // When you clicked on serach field, it will get becomeFirstResponder(),
    // and preparing NSText and focus will be taken by the NSText.
    // Problem is that self.currentEditor() hasn't been ready yet here.
    // So we have to wait resignFirstResponder() to get call and make sure
    // self.currentEditor() is ready.

    override func becomeFirstResponder() -> Bool {
        let status = super.becomeFirstResponder()
        if let _ = self.delegate as? ZSearchFieldDelegate where status == true {
            expectingCurrentEditor = true
        }
        return status
    }

    // It is pretty strange to detect search field get focused in resignFirstResponder()
    // method.  But otherwise, it is hard to tell if self.currentEditor() is available.
    // Once self.currentEditor() is there, that means the focus is moved from 
    // serach feild to NSText. So, tell it's delegate that the search field got focused.

    override func resignFirstResponder() -> Bool {
        let status = super.resignFirstResponder()
        if let delegate = self.delegate as? ZSearchFieldDelegate where status == true {
            if let _ = self.currentEditor() where expectingCurrentEditor {
                delegate.searchFieldDidBecomeFirstResponder(self)
                // currentEditor.delegate = self
            }
        }
        self.expectingCurrentEditor = false
        return status
    }

    // This method detect whether NSText lost it's focus or not.  Make sure
    // self.currentEditor() is nil, then that means the search field lost its focus,
    // and tell it's delegate that the search field lost its focus.

    override func textDidEndEditing(notification: NSNotification) {
        super.textDidEndEditing(notification)

        if let delegate = self.delegate as? ZSearchFieldDelegate {
            if self.currentEditor() == nil {
                delegate.searchFieldDidResignFirstResponder(self)
            }
        }
    }

}

您将需要更改NSSerachField为ZSearchField，并且您的客户端类必须符合ZSearchFieldDelegatenot NSTextFieldDelegate。这是一个例子。当用户单击搜索字段时，它会扩展其宽度，而当您单击其他位置时，通过更改NSLayoutConstraintInterface Builder 设置的值，搜索字段会失去焦点并缩小其宽度。

class MyViewController: NSViewController, ZSearchFieldDelegate {

    // [snip]

    @IBOutlet weak var searchFieldWidthConstraint: NSLayoutConstraint!

    func searchFieldDidBecomeFirstResponder(textField: ZSearchField) {
        self.searchFieldWidthConstraint.constant = 300
        self.view.layoutSubtreeIfNeeded()
    }

    func searchFieldDidResignFirstResponder(textField: ZSearchField) {
        self.searchFieldWidthConstraint.constant = 100
        self.view.layoutSubtreeIfNeeded()
    }

}

这可能取决于操作系统的行为，我在 El Capitan 10.11.4 上尝试过，并且成功了。

代码也可以从 Gist 复制。 https://gist.github.com/codelynx/aa7a41f5fd8069a3cfa2

Answer 2

我有一个NSTextField重写-becomeFirstResponder和的自定义子类-resignFirstResponder。它的-cellView属性需要符合声明的协议-textDidBecome/ResignFirstResponder:(NSTextField *)sender，但这足以让您了解总体思路。它可以轻松修改为发布通知，您的控制器可以注册为观察者。我希望这有帮助。

- (BOOL)becomeFirstResponder
{
    BOOL status = [super becomeFirstResponder];
    if (status)
        [self.cellView textFieldDidBecomeFirstResponder:self];
    return status;
}

- (BOOL)resignFirstResponder
{
    BOOL status = [super resignFirstResponder];
    if (status)
        [self.cellView textFieldDidResignFirstResponder:self];
    return status;
}