如何在NSPathComponentCell上设置工具提示

Question

我正在使用Cocoa的NSPathControl，我想在任何路径单元格的悬停处显示工具提示。

NSPathComponentCell似乎没有任何工具提示的默认实现。

我该怎么做呢?

Answer 1

我黑了一些东西，现在就可以了。我正在子类化NSPathControl, NSPathCell和NSPathComponentCell。

代码如下:

#import <Cocoa/Cocoa.h>
@interface BreadcrumbView : NSPathControl
@end

#import "BreadcrumbView.h"
#import "BreadcrumbCell.h"
#import "BreadcrumbComponentCell.h"
static BOOL isInitialized = NO;
@implementation BreadcrumbView
- (void)drawRect:(NSRect)dirtyRect
{
    [super drawRect:dirtyRect];
    if ( !isInitialized ) {
        isInitialized = YES;
        [self.cell addObserver:self forKeyPath:@"toolTip" options:NSKeyValueObservingOptionInitial context:nil];
    }
    // Drawing code here.
}
- (void) observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context {
    if ( [keyPath isEqualToString:@"toolTip"] ) {
        [self setToolTip: ((BreadcrumbCell*)object).toolTip];
    }
}
+ (Class)cellClass {
    return [BreadcrumbCell class];
}
@end

#import <Cocoa/Cocoa.h>
#import "BreadcrumbComponentCell.h"
@interface BreadcrumbCell : NSPathCell
@property NSString* toolTip;
- (BreadcrumbComponentCell*) getHoveredComponentCell;
@end

#import "BreadcrumbCell.h"
#import "BreadcrumbComponentCell.h"
@implementation BreadcrumbCell
- (BreadcrumbComponentCell*) getHoveredComponentCell {
    return (BreadcrumbComponentCell*)[self valueForKey:@"_hoveredCell"];
}
- (void) mouseEntered:(NSEvent *)event withFrame:(NSRect)frame inView:(NSView *)view{
    BreadcrumbComponentCell* componentCell = [self getHoveredComponentCell];
    if ( componentCell ) {
        self.toolTip = [componentCell getToolTip];
    }
}
+ (Class)pathComponentCellClass {
    return [BreadcrumbComponentCell class];
}
@end

#import <Cocoa/Cocoa.h>
@interface BreadcrumbComponentCell : NSPathComponentCell {
    NSString* tooltip;
}
- (void) setToolTip:(NSString*) text;
- (NSString*) getToolTip;
@end

#import "BreadcrumbComponentCell.h"
@implementation BreadcrumbComponentCell
- (void) setToolTip:(NSString*) text {
    tooltip = text;
}
- (NSString*) getToolTip{
    return tooltip;
}
@end

我希望这能帮别人节省我找它的时间。