objective-c - Cocoa - 当按下按键时 NSCursor 重置为默认光标

Question

我正在开发一个应用程序，该应用程序有一个带有全尺寸 NSOpenGLView 的窗口。我使用 [view addCursorRect] 和 [cursor set] 来显示自定义光标，但是当我按键盘上的任意键时，光标会重置为默认箭头。我还尝试过重写resetCursorRects并在按下按键时调用invalidateCursorRects，这会导致光标闪烁。

当我单击 View 中的任意位置时，光标会切换回自定义光标，因此我认为键盘按下会以某种方式使我的 View 失去焦点。有什么办法可以防止按下按键时 View 失去焦点吗？

Answer 1

您需要记住您的光标设置+当您需要重置调用时，例如refreshCursor方法。实现示例:

- (void)refreshCursor
{
    NSCursor *cursor = nil;
    if ([self graphic]) {
        cursor = [graphic hoverCursorForPoint:[self mousePosition]];
    } else if ([self group]){
        cursor = [NSCursor openHandCursor];
    }
    [self setHoverCursor:cursor];
    [self refresh];
}

- (void)updateTrackingAreas
{
    [super updateTrackingAreas];
    [self removeTrackingArea:[self trackingArea]];
    NSTrackingArea *area = [[NSTrackingArea alloc] initWithRect:[self visibleRect]
                                                        options:NSTrackingActiveAlways|NSTrackingMouseEnteredAndExited|NSTrackingMouseMoved
                                                          owner:self userInfo:nil];
    [self setTrackingArea:area];
    [self addTrackingArea:[self trackingArea]];
}

- (void)setCursorRects
{
    [self discardCursorRects];
    if ([self hoverCursor]) {
        [self addCursorRect:[self visibleRect] cursor:[self hoverCursor]];
    }
}

- (void)setHoverCursor:(NSCursor *)hoverCursor {
    if (_hoverCursor != hoverCursor) {
        _hoverCursor = hoverCursor;
        [self setCursorRects];
    }
}

- (void)resetCursorRects {
    [super resetCursorRects];
    [self setCursorRects];
}

- (void)mouseExited:(NSEvent *)event
{
    [[NSCursor currentSystemCursor] set];
}

- (void)mouseEntered:(NSEvent *)event
{
}

- (void)mouseMoved:(NSEvent *)event
{
    [self refreshCursor];
}

- (void)keyUp:(NSEvent *)event
{
  [self refreshCursor];
}

//allow key events
- (BOOL)acceptsFirstResponder
{
    return YES;
}