我應該在我的NSCell上調用什麼方法

Question

我正在使用自定義NSCell編寫自定義NSControl。它是一個控件，所以它必須響應鼠標。我創建了一個NSTrackingArea覆蓋我的控件，實現了-mouseEntered:，-mouseExited:和-mouseMoved:。 （我將不得不實施-mouseUp/Down:，但我不知道該做什麼，所以現在我還沒有重寫這些方法。）在這些方法中，我成功地確定了鼠標當前在哪個單元格上。現在我有兩個問題：

• 這是跟蹤鼠標的好方法嗎？如果不是，我該怎麼做呢？
• 在鼠標點擊，鼠標進入細胞，鼠標離開細胞等時，我應該在我的NSCell上調用什麼方法？蘋果的文檔對此並不十分清楚。

因此，基本上：什麼時候應該調用我的NSCell上的什麼方法讓它響應鼠標事件？

編輯：
李自成的文檔，我想我應該叫的NSCell的-trackMouse:inRect:ofView:untilMouseUp:並覆蓋-startTrackingAt:inView:，-continueTracking:at:inView:和-stopTracking:at:inView:mouseIsUp:。再次提出兩個問題：1）文檔給人留下的印象只有在鼠標關閉時才被調用。那是對的嗎？那我應該怎麼做呢？ 2）我應該在哪裏/何時致電NSCell的-trackMouse:inRect:ofView:untilMouseUp:？

Answer 1

我最終實現我自己的鼠標跟蹤機制：

// 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; 
} 

當然，在MyCell.h：

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

隨着這些方法的空實現（所以編譯器不抱怨我可以將鼠標處理方法的實現留給子類）。