objective-c - 使 NSLevelIndicator 绘制圆角边缘

Question

我想为我的 NSLevelIndicator 创建一个自定义类，它只是将边缘四舍五入。 (即像圆角矩形按钮)我创建了一个自定义类，我知道我必须在

-(void)drawRect:(NSRect)dirtyRect;

方法，但我完全不知道如何实现这一点，我希望有人对此有想法。

Answer 1

@interface DILevelIndicatorCell : NSLevelIndicatorCell

@property ( readwrite, assign ) BOOL drawBezel;

@property ( readwrite, assign ) BOOL verticalCenter;

@end

<小时/>

- ( void )drawWithFrame:( NSRect ) rcCellFrame inView:( NSView* ) pControlView
{

    NSRect rcInterior = rcCellFrame;

    if( _drawBezel )
    {
        [ self _drawBezelWithFrame:rcCellFrame ];

        rcInterior = NSInsetRect( rcCellFrame, 3, 3 );
    }

    if( _verticalCenter )
    {
        CGFloat i = ( NSHeight( rcInterior ) - [ self cellSize ].height ) / 2;
        rcInterior.origin.y    += i;
        rcInterior.size.height -= i;
    }    

    [ super drawWithFrame:rcInterior inView:pControlView ];
}

- ( void )_drawBezelWithFrame:( NSRect ) dirtyRect
{

    CGFloat fRoundedRadius = 10.0f;

    NSGraphicsContext* ctx = [ NSGraphicsContext currentContext ];
    [ ctx saveGraphicsState ];
    {
        NSBezierPath* pPath    = [ NSBezierPath bezierPathWithRoundedRect:dirtyRect
                                                                  xRadius:fRoundedRadius
                                                                  yRadius:fRoundedRadius ];
        [ pPath setClip ];

        [ [ NSColor colorWithCalibratedRed:0.9 green:0.9 blue:0.95 alpha:1.0 ] setFill ];
        NSRectFillUsingOperation ( dirtyRect, NSCompositeSourceOver );

         [ [ NSColor colorWithCalibratedRed:0.7 green:0.7 blue:0.85 alpha:1.0 ] setFill ];
        [ pPath setLineWidth:1 ];
        [ pPath stroke ];
    }
    [ ctx restoreGraphicsState ];
}