悬停在NSCollectionView中的效果

Question

我有NSCollectionView几个NSViews.其中NSView有一个NSBox在选择时改变颜色.我还希望NSBox在悬停时改变颜色.

我继承NSBox并添加了mouseEntered和mouseExited方法.我addTrackingRect在里面使用viewWillMoveToWindow但问题是只有当我第一次选择框所在的子视图时才会发生悬停效果.

此外,只有选中的框会在其上发生悬停效果.如何实现悬停过度效果,使NSView我的所有s NSCollectionView立即显示效果？

Answer 1

您可以updateTrackingAreas在子类中覆盖NSView以完成此行为：

界面

@interface HoverView : NSView

@property (strong, nonatomic) NSColor *hoverColor;

@end

执行

@interface HoverView ()

@property (strong, nonatomic) NSTrackingArea *trackingArea;
@property (assign, nonatomic) BOOL mouseInside;

@end

@implementation HoverView

- (void) drawRect:(NSRect)dirtyRect {
    [super drawRect:dirtyRect];

    // Draw a white/alpha gradient
    if (self.mouseInside) {
        [_hoverColor set];
        NSRectFill(self.bounds);
    }
}


- (void) updateTrackingAreas {
    [super updateTrackingAreas];

    [self ensureTrackingArea];
    if (![[self trackingAreas] containsObject:_trackingArea]) {
        [self addTrackingArea:_trackingArea];
    }
}

- (void) ensureTrackingArea {
    if (_trackingArea == nil) {
        self.trackingArea = [[NSTrackingArea alloc] initWithRect:NSZeroRect
                                                         options:NSTrackingInVisibleRect | NSTrackingActiveAlways | NSTrackingMouseEnteredAndExited
                                                           owner:self
                                                        userInfo:nil];
    }
}

- (void) mouseEntered:(NSEvent *)theEvent {
    self.mouseInside = YES;
}

- (void) mouseExited:(NSEvent *)theEvent {
    self.mouseInside = NO;
}

- (void) setMouseInside:(BOOL)value {
    if (_mouseInside != value) {
        _mouseInside = value;
        [self setNeedsDisplay:YES];
    }
}


@end