以编程方式将项目符号列表添加到 NSTextView 的两种方法：
方法一：
以下链接引导我使用第一种方法，但它没有必要迂回，除非您想对项目符号使用一些特殊的非 Unicode 字形：
- 在 NSTextView 中显示隐藏字符 https://stackoverflow.com/questions/300086/display-hidden-characters-in-nstextview
- 如何绘制一个没有 unicode 表示的 NSGlyph？ https://stackoverflow.com/questions/8472791/how-to-draw-one-nsglyph-that-hasnt-unicode-representation
- appendBezierPathWithGlyph 在 [NSBezierPath currentPoint] 中失败 https://stackoverflow.com/questions/2984776/appendbezierpathwithglyph-fails-in-nsbezierpath-currentpoint
这需要：（1）一个子类布局管理器，用项目符号符号替换某些任意字符； (2) 带有firstLineHeadIndent的段落样式，一个比该缩进稍大的制表位，以及将两者结合起来的用于换行的headIndent。
布局管理器如下所示：
#import <Foundation/Foundation.h>
@interface TickerLayoutManager : NSLayoutManager {
// Might as well let this class hold all the fonts used by the progress ticker.
// That way they're all defined in one place, the init method.
NSFont *fontNormal;
NSFont *fontIndent; // smaller, for indented lines
NSFont *fontBold;
NSGlyph glyphBullet;
CGFloat fWidthGlyphPlusSpace;
}
@property (nonatomic, retain) NSFont *fontNormal;
@property (nonatomic, retain) NSFont *fontIndent;
@property (nonatomic, retain) NSFont *fontBold;
@property NSGlyph glyphBullet;
@property CGFloat fWidthGlyphPlusSpace;
@end
#import "TickerLayoutManager.h"
@implementation TickerLayoutManager
@synthesize fontNormal;
@synthesize fontIndent;
@synthesize fontBold;
@synthesize glyphBullet;
@synthesize fWidthGlyphPlusSpace;
- (id)init {
self = [super init];
if (self) {
self.fontNormal = [NSFont fontWithName:@"Baskerville" size:14.0f];
self.fontIndent = [NSFont fontWithName:@"Baskerville" size:12.0f];
self.fontBold = [NSFont fontWithName:@"Baskerville Bold" size:14.0f];
// Get the bullet glyph.
self.glyphBullet = [self.fontIndent glyphWithName:@"bullet"];
// To determine its point size, put it in a Bezier path and take its bounds.
NSBezierPath *bezierPath = [NSBezierPath bezierPath];
[bezierPath moveToPoint:NSMakePoint(0.0f, 0.0f)]; // prevents "No current point for line" exception
[bezierPath appendBezierPathWithGlyph:self.glyphBullet inFont:self.fontIndent];
NSRect rectGlyphOutline = [bezierPath bounds];
// The bullet should be followed with a space, so get the combined size...
NSSize sizeSpace = [@" " sizeWithAttributes:[NSDictionary dictionaryWithObject:self.fontIndent forKey:NSFontAttributeName]];
self.fWidthGlyphPlusSpace = rectGlyphOutline.size.width + sizeSpace.width;
// ...which is for some reason inexact. If this number is too low, your bulleted text will be thrown to the line below, so add some boost.
self.fWidthGlyphPlusSpace *= 1.5; //
}
return self;
}
- (void)drawGlyphsForGlyphRange:(NSRange)range
atPoint:(NSPoint)origin {
// The following prints only once, even though the textview's string is set 4 times, so this implementation is not too expensive.
printf("\nCalling TickerLayoutManager's drawGlyphs method.");
NSString *string = [[self textStorage] string];
for (int i = range.location; i < range.length; i++) {
// Replace all occurrences of the ">" char with the bullet glyph.
if ([string characterAtIndex:i] == '>')
[self replaceGlyphAtIndex:i withGlyph:self.glyphBullet];
}
[super drawGlyphsForGlyphRange:range atPoint:origin];
}
@end
将布局管理器分配给窗口/视图控制器的 awakeFromNib 中的文本视图，如下所示：
- (void) awakeFromNib {
// regular setup...
// Give the ticker display NSTextView its subclassed layout manager.
TickerLayoutManager *newLayoutMgr = [[TickerLayoutManager alloc] init];
NSTextContainer *textContainer = [self.txvProgressTicker textContainer];
// Use "replaceLM" rather than "setLM," in order to keep shared relnshps intact.
[textContainer replaceLayoutManager:newLayoutMgr];
[newLayoutMgr release];
// (Note: It is possible that all text-displaying controls in this class’s window will share this text container, as they would a field editor (a textview), although the fact that the ticker display is itself a textview might isolate it. Apple's "Text System Overview" is not clear on this point.)
}
然后添加一个类似这样的方法：
- (void) addProgressTickerLine:(NSString *)string
inStyle:(uint8_t)uiStyle {
// Null check.
if (!string)
return;
// Prepare the font.
// (As noted above, TickerLayoutManager holds all 3 ticker display fonts.)
NSFont *font = nil;
TickerLayoutManager *tickerLayoutMgr = (TickerLayoutManager *)[self.txvProgressTicker layoutManager];
switch (uiStyle) {
case kTickerStyleNormal:
font = tickerLayoutMgr.fontNormal;
break;
case kTickerStyleIndent:
font = tickerLayoutMgr.fontIndent;
break;
case kTickerStyleBold:
font = tickerLayoutMgr.fontBold;
break;
default:
font = tickerLayoutMgr.fontNormal;
break;
}
// Prepare the paragraph style, to govern indentation.
// CAUTION: If you propertize it for re-use, make sure you don't mutate it once it has been assigned to an attributed string. (See warning in class ref.)
// At the same time, add the initial line break and, if indented, the tab.
NSMutableParagraphStyle *paragStyle = [[NSParagraphStyle defaultParagraphStyle] mutableCopy]; // ALLOC
[paragStyle setAlignment:NSLeftTextAlignment]; // default, but just in case
if (uiStyle == kTickerStyleIndent) {
// (The custom layout mgr will replace ‘>’ char with a bullet, so it should be followed with an extra space.)
string = [@"\n>\t" stringByAppendingString:string];
// Indent the first line up to where the bullet should appear.
[paragStyle setFirstLineHeadIndent:15.0f];
// Define a tab stop to the right of the bullet glyph.
NSTextTab *textTabFllwgBullet = [[NSTextTab alloc] initWithType:NSLeftTabStopType location:15.0f + tickerLayoutMgr.fWidthGlyphPlusSpace];
[paragStyle setTabStops:[NSArray arrayWithObject:textTabFllwgBullet]];
[textTabFllwgBullet release];
// Set the indentation for the wrapped lines to the same place as the tab stop.
[paragStyle setHeadIndent:15.0f + tickerLayoutMgr.fWidthGlyphPlusSpace];
}
else {
string = [@"\n" stringByAppendingString:string];
}
// PUT IT ALL TOGETHER.
// Combine the above into a dictionary of attributes.
NSDictionary *dict = [NSDictionary dictionaryWithObjectsAndKeys:
font, NSFontAttributeName,
paragStyle, NSParagraphStyleAttributeName,
nil];
// Use the attributes dictionary to make an attributed string out of the plain string.
NSAttributedString *attrs = [[NSAttributedString alloc] initWithString:string attributes:dict]; // ALLOC
// Append the attributed string to the ticker display.
[[self.txvProgressTicker textStorage] appendAttributedString:attrs];
// RELEASE
[attrs release];
[paragStyle release];
}
测试一下：
NSString *sTicker = NSLocalizedString(@"First normal line of ticker should wrap to left margin", @"First normal line of ticker should wrap to left margin");
[self addProgressTickerLine:sTicker inStyle:kTickerStyleNormal];
sTicker = NSLocalizedString(@"Indented ticker line should have bullet point and should wrap farther to right.", @"Indented ticker line should have bullet point and should wrap farther to right.");
[self addProgressTickerLine:sTicker inStyle:kTickerStyleIndent];
sTicker = NSLocalizedString(@"Try a second indented line, to make sure both line up.", @"Try a second indented line, to make sure both line up.");
[self addProgressTickerLine:sTicker inStyle:kTickerStyleIndent];
sTicker = NSLocalizedString(@"Final bold line", @"Final bold line");
[self addProgressTickerLine:sTicker inStyle:kTickerStyleBold];
你得到这个：
方法二：
但项目符号是一个常规的 Unicode 字符，十六进制为 2022。因此您可以直接将其放入字符串中，并获得精确的测量值，如下所示：
NSString *stringWithGlyph = [NSString stringWithUTF8String:"\u2022"];
NSString *stringWithGlyphPlusSpace = [stringWithGlyph stringByAppendingString:@" "];
NSSize sizeGlyphPlusSpace = [stringWithGlyphPlusSpace sizeWithAttributes:[NSDictionary dictionaryWithObject:self.fontIndent forKey:NSFontAttributeName]];
self.fWidthGlyphPlusSpace = sizeGlyphPlusSpace.width;
所以不需要自定义布局管理器。只需如上所述设置 paragStyle 缩进，并将文本字符串附加到包含行 return + 项目符号字符 + 空格（或 + tab，在这种情况下您仍然需要该制表位）的字符串。
使用空格，这会产生更紧凑的结果：
想要使用子弹以外的角色吗？这是一个漂亮的 Unicode 图表：http://www.danshort.com/unicode/ http://www.danshort.com/unicode/
