我应该在我的NSCell上调用什么方法

Question

我正在使用自定义NSCell编写自定义NSControl。它是一个控件，所以它必须响应鼠标。我创建了一个NSTrackingArea覆盖我的控件，实现了-mouseEntered:，-mouseExited:和-mouseMoved:。 （我将不得不实施-mouseUp/Down:，但我不知道该做什么，所以现在我还没有重写这些方法。）在这些方法中，我成功地确定了鼠标当前在哪个单元格上。现在我有两个问题：

• 这是跟踪鼠标的好方法吗？如果不是，我该怎么做呢？
• 在鼠标点击，鼠标进入细胞，鼠标离开细胞等时，我应该在我的NSCell上调用什么方法？苹果的文档对此并不十分清楚。

因此，基本上：什么时候应该调用我的NSCell上的什么方法让它响应鼠标事件？

编辑：
李自成的文档，我想我应该叫的NSCell的-trackMouse:inRect:ofView:untilMouseUp:并覆盖-startTrackingAt:inView:，-continueTracking:at:inView:和-stopTracking:at:inView:mouseIsUp:。再次提出两个问题：1）文档给人留下的印象只有在鼠标关闭时才被调用。那是对的吗？那我应该怎么做呢？ 2）我应该在哪里/何时致电NSCell的-trackMouse:inRect:ofView:untilMouseUp:？

Answer 1

我最终实现我自己的鼠标跟踪机制：

// MyControl.m: 

- (void)mouseDown:(NSEvent *)theEvent { 
    int currentCellIndex = [self indexOfCellAtPoint:[self convertPoint:[theEvent locationInWindow] fromView:nil]]; 
    if (currentCellIndex < [cells count]) { 
     MKListCell *cell = [cells objectAtIndex:currentCellIndex]; 
     currentCell = cell; 
     [currentCell mouseDown:theEvent]; 
    } 
} 

- (void)mouseUp:(NSEvent *)theEvent { 
    int currentCellIndex = [self indexOfCellAtPoint:[self convertPoint:[theEvent locationInWindow] fromView:nil]]; 
    if (currentCellIndex < [cells count]) { 
     MKListCell *cell = [cells objectAtIndex:currentCellIndex]; 
     [cell mouseUp:theEvent]; 
    } 
} 

- (void)mouseEntered:(NSEvent *)theEvent { 
    int currentCellIndex = [self indexOfCellAtPoint:[self convertPoint:[theEvent locationInWindow] fromView:nil]]; 
    if (currentCellIndex < [cells count]) { 
     MKListCell *cell = [cells objectAtIndex:currentCellIndex]; 
     currentCell = cell; 
     [currentCell mouseEntered:theEvent]; 
    } 
} 

- (void)mouseExited:(NSEvent *)theEvent { 
    int currentCellIndex = [self indexOfCellAtPoint:[self convertPoint:[theEvent locationInWindow] fromView:nil]]; 
    if (currentCellIndex < [cells count]) { 
     MKListCell *cell = [cells objectAtIndex:currentCellIndex]; 
     [cell mouseExited:theEvent]; 
     currentCell = nil; 
    } 
} 

- (void)mouseMoved:(NSEvent *)theEvent { 
    int currentCellIndex = [self indexOfCellAtPoint:[self convertPoint:[theEvent locationInWindow] fromView:nil]]; 
    MKListCell *cell; 
    if (currentCellIndex < [cells count]) { 
     cell = [cells objectAtIndex:currentCellIndex]; 
    } 
    if (currentCell != cell) { 
     [currentCell mouseExited:theEvent]; 
     [cell mouseEntered:theEvent]; 
     currentCell = cell; 
    } 
    else { 
     [currentCell mouseMoved:theEvent]; 
    } 
} 

- (void)mouseDragged:(NSEvent *)theEvent { 
    int currentCellIndex = [self indexOfCellAtPoint:[self convertPoint:[theEvent locationInWindow] fromView:nil]]; 
    MKListCell *cell = nil; 
    if (currentCellIndex < [cells count]) { 
     cell = [cells objectAtIndex:currentCellIndex]; 
    } 
    if (currentCell != cell) { 
     [currentCell mouseExited:theEvent]; 
     [cell mouseEntered:theEvent]; 
     currentCell = cell; 
    } 
    else { 
     [currentCell mouseMoved:theEvent]; 
    } 
} 

- (int)indexOfCellAtPoint:(NSPoint)p { 
    int cellIndex = (self.bounds.size.height - p.y)/cellHeight; 
    return cellIndex; 
} 

当然，在MyCell.h：

- (void)mouseDown:(NSEvent *)event; 
- (void)mouseUp:(NSEvent *)event; 
- (void)mouseMoved:(NSEvent *)event; 
- (void)mouseEntered:(NSEvent *)event; 
- (void)mouseExited:(NSEvent *)event; 

随着这些方法的空实现（所以编译器不抱怨我可以将鼠标处理方法的实现留给子类）。