可可:如何使用方法drawlabel:inRect在可可中向NSTabViewItem添加图标

Question

我想在NSTabViewItem中添加一个带有一些文本的图标。

请帮助我使用drawLabel:inRect:方法中的代码。

- (id)initWithCoder:(NSCoder *)decoder
{
[super initWithCoder:decoder];
tabCell = [[NSBrowserCell alloc] initImageCell:[NSImage 
imageNamed:@"xyz"]];
[tabCell setLeaf:YES];
[tabCell setFont:[[self tabView] font]];
[tabCell setStringValue: [self label]];
return self;
}
- (void)drawLabel:(BOOL)shouldTruncateLabel inRect:(NSRect)tabRect
{
{ //  modify the rect a tad so the cell draws properly..
    tabRect.origin.y += 2;
    tabRect.size.width += 16;
}
[tabCell drawWithFrame:tabRect inView:[self tabView]];
}

- (NSSize)sizeOfLabel:(BOOL)shouldTruncateLabel
{
NSSize superSize = [super sizeOfLabel:shouldTruncateLabel];
NSImage *icon = [tabCell image];
superSize.width += [icon size].width-4;
return superSize;
}

我可以在NSTabViewItem中添加一个图标，但由于图标太大，它从选项卡中出来了。如何保持图标的大小以保持在TabViewItem内？

Answer 1

不确定，如果你的问题得到解决，我有类似的用例，我使用drawLabel并在其中添加图像，

参考代码片段，

- (void)drawLabel:(BOOL)shouldTruncateLabel inRect:(NSRect)tabRect{

    NSImage *pImage = [self getImage];
    [[NSGraphicsContext currentContext] saveGraphicsState];
    NSAffineTransform* xform = [NSAffineTransform transform];
    [xform translateXBy:0.0 yBy: tabRect.size.height];
    [xform scaleXBy:1.0 yBy:-1.0];
    [xform concat]; 

    if(pImage){
        [pImage drawInRect:NSMakeRect(tabRect.origin.x-8,-6,16, 16)fromRect:NSZeroRect
                 operation:NSCompositeSourceOver
                  fraction:opacity];
    }
     [[NSGraphicsContext currentContext] restoreGraphicsState];
    [super drawLabel:shouldTruncateLabel inRect:tabRect];
    NSLog(@" Inside drawRect text (%@)",[self labeltitle]);
}

Answer 2

此代码适用于我（Swift 3）：

import Foundation
import Cocoa
class MyTabViewItem : NSTabViewItem
{
    let iconWidth:CGFloat = 16
    override func sizeOfLabel(_ shouldTruncateLabel: Bool) -> NSSize
    {
        var superSize: NSSize = super.sizeOfLabel(shouldTruncateLabel)
        superSize.width += iconWidth
        return superSize
    }
    override func drawLabel(_ shouldTruncateLabel: Bool, in tabRect: NSRect)
    {
        let icon: NSImage? = NSImage(named:"Eye")
        if icon != nil
        {
            let opacity:CGFloat = 0.5
            icon?.draw(in: NSMakeRect(tabRect.origin.x + tabRect.width - iconWidth + 4, 8, iconWidth, iconWidth), from: NSZeroRect, operation: NSCompositeSourceOver, fraction: opacity)
        }
        super.drawLabel(shouldTruncateLabel, in: tabRect)  
    }
}

没有经过完全测试，如果iconWidth发生变化，您可能需要更改一些常量。

Answer 3

基于Amitg2k12的示例，添加了一些内容：

- (id)initWithCoder:(NSCoder *)decoder {
    self = [super initWithCoder:decoder];
    if (self) {
        [self setToolTip:[self label]];
        [self setLabel:@" "];
    }
    return self;
}
- (NSSize)sizeOfLabel:(BOOL)computeMin {
    return NSMakeSize(16, 18);
}
- (void)drawLabel:(BOOL)shouldTruncateLabel inRect:(NSRect)tabRect {
    NSImage *image = [self image];
    NSRect destRect = NSMakeRect(tabRect.origin.x, tabRect.origin.y + 2, 16, 16);
    [[NSGraphicsContext currentContext] saveGraphicsState];
    NSAffineTransform *affineTransform = [NSAffineTransform transform];
    [affineTransform translateXBy:NSMaxX(destRect) yBy:NSMinY(destRect)];
    [affineTransform scaleXBy:1.0 yBy:-1.0];
    [affineTransform concat];
    if(image) {
        [image drawInRect:NSMakeRect(-NSWidth(destRect), -NSHeight(destRect), 16, 16) fromRect:NSZeroRect
                operation:NSCompositeSourceOver
                 fraction:1.0f];
    }
    [[NSGraphicsContext currentContext] restoreGraphicsState];
    [super drawLabel:shouldTruncateLabel inRect:tabRect];
}
@end