1 files changed, 597 insertions, 0 deletions

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+//
+//  ZAttributedString.m
+//  FontLabel
+//
+//  Created by Kevin Ballard on 9/22/09.
+//  Copyright 2009 Zynga Game Networks. All rights reserved.
+//
+
+#import "ZAttributedString.h"
+#import "ZAttributedStringPrivate.h"
+
+@interface ZAttributedString ()
+- (NSUInteger)indexOfEffectiveAttributeRunForIndex:(NSUInteger)index;
+- (NSDictionary *)attributesAtIndex:(NSUInteger)index effectiveRange:(NSRangePointer)aRange uniquingOnName:(NSString *)attributeName;
+- (NSDictionary *)attributesAtIndex:(NSUInteger)index longestEffectiveRange:(NSRangePointer)aRange
+                                                        inRange:(NSRange)rangeLimit uniquingOnName:(NSString *)attributeName;
+@end
+
+@interface ZAttributedString ()
+@property (nonatomic, readonly) NSArray *attributes;
+@end
+
+@implementation ZAttributedString
+@synthesize string = _buffer;
+@synthesize attributes = _attributes;
+
+- (id)initWithAttributedString:(ZAttributedString *)attr {
+        NSParameterAssert(attr != nil);
+        if ((self = [super init])) {
+                _buffer = [attr->_buffer mutableCopy];
+                _attributes = [[NSMutableArray alloc] initWithArray:attr->_attributes copyItems:YES];
+        }
+        return self;
+}
+
+- (id)initWithString:(NSString *)str {
+        return [self initWithString:str attributes:nil];
+}
+
+- (id)initWithString:(NSString *)str attributes:(NSDictionary *)attributes {
+        if ((self = [super init])) {
+                _buffer = [str mutableCopy];
+                _attributes = [[NSMutableArray alloc] initWithObjects:[ZAttributeRun attributeRunWithIndex:0 attributes:attributes], nil];
+        }
+        return self;
+}
+
+- (id)init {
+        return [self initWithString:@"" attributes:nil];
+}
+
+- (id)initWithCoder:(NSCoder *)decoder {
+        if ((self = [super init])) {
+                _buffer = [[decoder decodeObjectForKey:@"buffer"] mutableCopy];
+                _attributes = [[decoder decodeObjectForKey:@"attributes"] mutableCopy];
+        }
+        return self;
+}
+
+- (void)encodeWithCoder:(NSCoder *)aCoder {
+        [aCoder encodeObject:_buffer forKey:@"buffer"];
+        [aCoder encodeObject:_attributes forKey:@"attributes"];
+}
+
+- (id)copyWithZone:(NSZone *)zone {
+        return [self retain];
+}
+
+- (id)mutableCopyWithZone:(NSZone *)zone {
+        return [(ZMutableAttributedString *)[ZMutableAttributedString allocWithZone:zone] initWithAttributedString:self];
+}
+
+- (NSUInteger)length {
+        return [_buffer length];
+}
+
+- (NSString *)description {
+        NSMutableArray *components = [NSMutableArray arrayWithCapacity:[_attributes count]*2];
+        NSRange range = NSMakeRange(0, 0);
+        for (NSUInteger i = 0; i <= [_attributes count]; i++) {
+                range.location = NSMaxRange(range);
+                ZAttributeRun *run;
+                if (i < [_attributes count]) {
+                        run = [_attributes objectAtIndex:i];
+                        range.length = run.index - range.location;
+                } else {
+                        run = nil;
+                        range.length = [_buffer length] - range.location;
+                }
+                if (range.length > 0) {
+                        [components addObject:[NSString stringWithFormat:@"\"%@\"", [_buffer substringWithRange:range]]];
+                }
+                if (run != nil) {
+                        NSMutableArray *attrDesc = [NSMutableArray arrayWithCapacity:[run.attributes count]];
+                        for (id key in run.attributes) {
+                                [attrDesc addObject:[NSString stringWithFormat:@"%@: %@", key, [run.attributes objectForKey:key]]];
+                        }
+                        [components addObject:[NSString stringWithFormat:@"{%@}", [attrDesc componentsJoinedByString:@", "]]];
+                }
+        }
+        return [NSString stringWithFormat:@"%@", [components componentsJoinedByString:@" "]];
+}
+
+- (id)attribute:(NSString *)attributeName atIndex:(NSUInteger)index effectiveRange:(NSRangePointer)aRange {
+        NSParameterAssert(attributeName != nil);
+        return [[self attributesAtIndex:index effectiveRange:aRange uniquingOnName:attributeName] objectForKey:attributeName];
+}
+
+- (id)attribute:(NSString *)attributeName atIndex:(NSUInteger)index longestEffectiveRange:(NSRangePointer)aRange inRange:(NSRange)rangeLimit {
+        NSParameterAssert(attributeName != nil);
+        return [[self attributesAtIndex:index longestEffectiveRange:aRange inRange:rangeLimit uniquingOnName:attributeName] objectForKey:attributeName];
+}
+
+- (ZAttributedString *)attributedSubstringFromRange:(NSRange)aRange {
+        if (NSMaxRange(aRange) > [_buffer length]) {
+                @throw [NSException exceptionWithName:NSRangeException reason:@"range was outisde of the attributed string" userInfo:nil];
+        }
+        ZMutableAttributedString *newStr = [self mutableCopy];
+        if (aRange.location > 0) {
+                [newStr deleteCharactersInRange:NSMakeRange(0, aRange.location)];
+        }
+        if (NSMaxRange(aRange) < [_buffer length]) {
+                [newStr deleteCharactersInRange:NSMakeRange(aRange.length, [_buffer length] - NSMaxRange(aRange))];
+        }
+        return [newStr autorelease];
+}
+
+- (NSDictionary *)attributesAtIndex:(NSUInteger)index effectiveRange:(NSRangePointer)aRange {
+        return [NSDictionary dictionaryWithDictionary:[self attributesAtIndex:index effectiveRange:aRange uniquingOnName:nil]];
+}
+
+- (NSDictionary *)attributesAtIndex:(NSUInteger)index longestEffectiveRange:(NSRangePointer)aRange inRange:(NSRange)rangeLimit {
+        return [NSDictionary dictionaryWithDictionary:[self attributesAtIndex:index longestEffectiveRange:aRange inRange:rangeLimit uniquingOnName:nil]];
+}
+
+#if Z_BLOCKS
+// Warning: this code has not been tested. The only guarantee is that it compiles.
+- (void)enumerateAttribute:(NSString *)attrName inRange:(NSRange)enumerationRange options:(ZAttributedStringEnumerationOptions)opts
+                                usingBlock:(void (^)(id, NSRange, BOOL*))block {
+        if (opts & ZAttributedStringEnumerationLongestEffectiveRangeNotRequired) {
+                [self enumerateAttributesInRange:enumerationRange options:opts usingBlock:^(NSDictionary *attrs, NSRange range, BOOL *stop) {
+                        id value = [attrs objectForKey:attrName];
+                        if (value != nil) {
+                                block(value, range, stop);
+                        }
+                }];
+        } else {
+                __block id oldValue = nil;
+                __block NSRange effectiveRange = NSMakeRange(0, 0);
+                [self enumerateAttributesInRange:enumerationRange options:opts usingBlock:^(NSDictionary *attrs, NSRange range, BOOL *stop) {
+                        id value = [attrs objectForKey:attrName];
+                        if (oldValue == nil) {
+                                oldValue = value;
+                                effectiveRange = range;
+                        } else if (value != nil && [oldValue isEqual:value]) {
+                                // combine the attributes
+                                effectiveRange = NSUnionRange(effectiveRange, range);
+                        } else {
+                                BOOL innerStop = NO;
+                                block(oldValue, effectiveRange, &innerStop);
+                                if (innerStop) {
+                                        *stop = YES;
+                                        oldValue = nil;
+                                } else {
+                                        oldValue = value;
+                                }
+                        }
+                }];
+                if (oldValue != nil) {
+                        BOOL innerStop = NO; // necessary for the block, but unused
+                        block(oldValue, effectiveRange, &innerStop);
+                }
+        }
+}
+
+- (void)enumerateAttributesInRange:(NSRange)enumerationRange options:(ZAttributedStringEnumerationOptions)opts
+                                                usingBlock:(void (^)(NSDictionary*, NSRange, BOOL*))block {
+        // copy the attributes so we can mutate the string if necessary during enumeration
+        // also clip the array during copy to only the subarray of attributes that cover the requested range
+        NSArray *attrs;
+        if (NSEqualRanges(enumerationRange, NSMakeRange(0, 0))) {
+                attrs = [NSArray arrayWithArray:_attributes];
+        } else {
+                // in this binary search, last is the first run after the range
+                NSUInteger first = 0, last = [_attributes count];
+                while (last > first+1) {
+                        NSUInteger pivot = (last + first) / 2;
+                        ZAttributeRun *run = [_attributes objectAtIndex:pivot];
+                        if (run.index < enumerationRange.location) {
+                                first = pivot;
+                        } else if (run.index >= NSMaxRange(enumerationRange)) {
+                                last = pivot;
+                        }
+                }
+                attrs = [_attributes subarrayWithRange:NSMakeRange(first, last-first)];
+        }
+        if (opts & ZAttributedStringEnumerationReverse) {
+                NSUInteger end = [_buffer length];
+                for (ZAttributeRun *run in [attrs reverseObjectEnumerator]) {
+                        BOOL stop = NO;
+                        NSUInteger start = run.index;
+                        // clip to enumerationRange
+                        start = MAX(start, enumerationRange.location);
+                        end = MIN(end, NSMaxRange(enumerationRange));
+                        block(run.attributes, NSMakeRange(start, end - start), &stop);
+                        if (stop) break;
+                        end = run.index;
+                }
+        } else {
+                NSUInteger start = 0;
+                ZAttributeRun *run = [attrs objectAtIndex:0];
+                NSInteger offset = 0;
+                NSInteger oldLength = [_buffer length];
+                for (NSUInteger i = 1;;i++) {
+                        NSUInteger end;
+                        if (i >= [attrs count]) {
+                                end = oldLength;
+                        } else {
+                                end = [[attrs objectAtIndex:i] index];
+                        }
+                        BOOL stop = NO;
+                        NSUInteger clippedStart = MAX(start, enumerationRange.location);
+                        NSUInteger clippedEnd = MIN(end, NSMaxRange(enumerationRange));
+                        block(run.attributes, NSMakeRange(clippedStart + offset, clippedEnd - start), &stop);
+                        if (stop || i >= [attrs count]) break;
+                        start = end;
+                        NSUInteger newLength = [_buffer length];
+                        offset += (newLength - oldLength);
+                        oldLength = newLength;
+                }
+        }
+}
+#endif
+
+- (BOOL)isEqualToAttributedString:(ZAttributedString *)otherString {
+        return ([_buffer isEqualToString:otherString->_buffer] && [_attributes isEqualToArray:otherString->_attributes]);
+}
+
+- (BOOL)isEqual:(id)object {
+        return [object isKindOfClass:[ZAttributedString class]] && [self isEqualToAttributedString:(ZAttributedString *)object];
+}
+
+#pragma mark -
+
+- (NSUInteger)indexOfEffectiveAttributeRunForIndex:(NSUInteger)index {
+        NSUInteger first = 0, last = [_attributes count];
+        while (last > first + 1) {
+                NSUInteger pivot = (last + first) / 2;
+                ZAttributeRun *run = [_attributes objectAtIndex:pivot];
+                if (run.index > index) {
+                        last = pivot;
+                } else if (run.index < index) {
+                        first = pivot;
+                } else {
+                        first = pivot;
+                        break;
+                }
+        }
+        return first;
+}
+
+- (NSDictionary *)attributesAtIndex:(NSUInteger)index effectiveRange:(NSRangePointer)aRange uniquingOnName:(NSString *)attributeName {
+        if (index >= [_buffer length]) {
+                @throw [NSException exceptionWithName:NSRangeException reason:@"index beyond range of attributed string" userInfo:nil];
+        }
+        NSUInteger runIndex = [self indexOfEffectiveAttributeRunForIndex:index];
+        ZAttributeRun *run = [_attributes objectAtIndex:runIndex];
+        if (aRange != NULL) {
+                aRange->location = run.index;
+                runIndex++;
+                if (runIndex < [_attributes count]) {
+                        aRange->length = [[_attributes objectAtIndex:runIndex] index] - aRange->location;
+                } else {
+                        aRange->length = [_buffer length] - aRange->location;
+                }
+        }
+        return run.attributes;
+}
+- (NSDictionary *)attributesAtIndex:(NSUInteger)index longestEffectiveRange:(NSRangePointer)aRange
+                                                        inRange:(NSRange)rangeLimit uniquingOnName:(NSString *)attributeName {
+        if (index >= [_buffer length]) {
+                @throw [NSException exceptionWithName:NSRangeException reason:@"index beyond range of attributed string" userInfo:nil];
+        } else if (NSMaxRange(rangeLimit) > [_buffer length]) {
+                @throw [NSException exceptionWithName:NSRangeException reason:@"rangeLimit beyond range of attributed string" userInfo:nil];
+        }
+        NSUInteger runIndex = [self indexOfEffectiveAttributeRunForIndex:index];
+        ZAttributeRun *run = [_attributes objectAtIndex:runIndex];
+        if (aRange != NULL) {
+                if (attributeName != nil) {
+                        id value = [run.attributes objectForKey:attributeName];
+                        NSUInteger endRunIndex = runIndex+1;
+                        runIndex--;
+                        // search backwards
+                        while (1) {
+                                if (run.index <= rangeLimit.location) {
+                                        break;
+                                }
+                                ZAttributeRun *prevRun = [_attributes objectAtIndex:runIndex];
+                                id prevValue = [prevRun.attributes objectForKey:attributeName];
+                                if (prevValue == value || (value != nil && [prevValue isEqual:value])) {
+                                        runIndex--;
+                                        run = prevRun;
+                                } else {
+                                        break;
+                                }
+                        }
+                        // search forwards
+                        ZAttributeRun *endRun = nil;
+                        while (endRunIndex < [_attributes count]) {
+                                ZAttributeRun *nextRun = [_attributes objectAtIndex:endRunIndex];
+                                if (nextRun.index >= NSMaxRange(rangeLimit)) {
+                                        endRun = nextRun;
+                                        break;
+                                }
+                                id nextValue = [nextRun.attributes objectForKey:attributeName];
+                                if (nextValue == value || (value != nil && [nextValue isEqual:value])) {
+                                        endRunIndex++;
+                                } else {
+                                        endRun = nextRun;
+                                        break;
+                                }
+                        }
+                        aRange->location = MAX(run.index, rangeLimit.location);
+                        aRange->length = MIN((endRun ? endRun.index : [_buffer length]), NSMaxRange(rangeLimit)) - aRange->location;
+                } else {
+                        // with no attribute name, we don't need to do any real searching,
+                        // as we already guarantee each run has unique attributes.
+                        // just make sure to clip the range to the rangeLimit
+                        aRange->location = MAX(run.index, rangeLimit.location);
+                        ZAttributeRun *endRun = (runIndex+1 < [_attributes count] ? [_attributes objectAtIndex:runIndex+1] : nil);
+                        aRange->length = MIN((endRun ? endRun.index : [_buffer length]), NSMaxRange(rangeLimit)) - aRange->location;
+                }
+        }
+        return run.attributes;
+}
+
+- (void)dealloc {
+        [_buffer release];
+        [_attributes release];
+        [super dealloc];
+}
+@end
+
+@interface ZMutableAttributedString ()
+- (void)cleanupAttributesInRange:(NSRange)range;
+- (NSRange)rangeOfAttributeRunsForRange:(NSRange)range;
+- (void)offsetRunsInRange:(NSRange )range byOffset:(NSInteger)offset;
+@end
+
+@implementation ZMutableAttributedString
+- (id)copyWithZone:(NSZone *)zone {
+        return [(ZAttributedString *)[ZAttributedString allocWithZone:zone] initWithAttributedString:self];
+}
+
+- (void)addAttribute:(NSString *)name value:(id)value range:(NSRange)range {
+        range = [self rangeOfAttributeRunsForRange:range];
+        for (ZAttributeRun *run in [_attributes subarrayWithRange:range]) {
+                [run.attributes setObject:value forKey:name];
+        }
+        [self cleanupAttributesInRange:range];
+}
+
+- (void)addAttributes:(NSDictionary *)attributes range:(NSRange)range {
+        range = [self rangeOfAttributeRunsForRange:range];
+        for (ZAttributeRun *run in [_attributes subarrayWithRange:range]) {
+                [run.attributes addEntriesFromDictionary:attributes];
+        }
+        [self cleanupAttributesInRange:range];
+}
+
+- (void)appendAttributedString:(ZAttributedString *)str {
+        [self insertAttributedString:str atIndex:[_buffer length]];
+}
+
+- (void)deleteCharactersInRange:(NSRange)range {
+        NSRange runRange = [self rangeOfAttributeRunsForRange:range];
+        [_buffer replaceCharactersInRange:range withString:@""];
+        [_attributes removeObjectsInRange:runRange];
+        for (NSUInteger i = runRange.location; i < [_attributes count]; i++) {
+                ZAttributeRun *run = [_attributes objectAtIndex:i];
+                ZAttributeRun *newRun = [[ZAttributeRun alloc] initWithIndex:(run.index - range.length) attributes:run.attributes];
+                [_attributes replaceObjectAtIndex:i withObject:newRun];
+                [newRun release];
+        }
+        [self cleanupAttributesInRange:NSMakeRange(runRange.location, 0)];
+}
+
+- (void)insertAttributedString:(ZAttributedString *)str atIndex:(NSUInteger)idx {
+        [self replaceCharactersInRange:NSMakeRange(idx, 0) withAttributedString:str];
+}
+
+- (void)removeAttribute:(NSString *)name range:(NSRange)range {
+        range = [self rangeOfAttributeRunsForRange:range];
+        for (ZAttributeRun *run in [_attributes subarrayWithRange:range]) {
+                [run.attributes removeObjectForKey:name];
+        }
+        [self cleanupAttributesInRange:range];
+}
+
+- (void)replaceCharactersInRange:(NSRange)range withAttributedString:(ZAttributedString *)str {
+        NSRange replaceRange = [self rangeOfAttributeRunsForRange:range];
+        NSInteger offset = [str->_buffer length] - range.length;
+        [_buffer replaceCharactersInRange:range withString:str->_buffer];
+        [_attributes replaceObjectsInRange:replaceRange withObjectsFromArray:str->_attributes];
+        NSRange newRange = NSMakeRange(replaceRange.location, [str->_attributes count]);
+        [self offsetRunsInRange:newRange byOffset:range.location];
+        [self offsetRunsInRange:NSMakeRange(NSMaxRange(newRange), [_attributes count] - NSMaxRange(newRange)) byOffset:offset];
+        [self cleanupAttributesInRange:NSMakeRange(newRange.location, 0)];
+        [self cleanupAttributesInRange:NSMakeRange(NSMaxRange(newRange), 0)];
+}
+
+- (void)replaceCharactersInRange:(NSRange)range withString:(NSString *)str {
+        [self replaceCharactersInRange:range withAttributedString:[[[ZAttributedString alloc] initWithString:str] autorelease]];
+}
+
+- (void)setAttributedString:(ZAttributedString *)str {
+        [_buffer release], _buffer = [str->_buffer mutableCopy];
+        [_attributes release], _attributes = [str->_attributes mutableCopy];
+}
+
+- (void)setAttributes:(NSDictionary *)attributes range:(NSRange)range {
+        range = [self rangeOfAttributeRunsForRange:range];
+        for (ZAttributeRun *run in [_attributes subarrayWithRange:range]) {
+                [run.attributes setDictionary:attributes];
+        }
+        [self cleanupAttributesInRange:range];
+}
+
+#pragma mark -
+
+// splits the existing runs to provide one or more new runs for the given range
+- (NSRange)rangeOfAttributeRunsForRange:(NSRange)range {
+        NSParameterAssert(NSMaxRange(range) <= [_buffer length]);
+        
+        // find (or create) the first run
+        NSUInteger first = 0;
+        ZAttributeRun *lastRun = nil;
+        for (;;first++) {
+                if (first >= [_attributes count]) {
+                        // we didn't find a run
+                        first = [_attributes count];
+                        ZAttributeRun *newRun = [[ZAttributeRun alloc] initWithIndex:range.location attributes:lastRun.attributes];
+                        [_attributes addObject:newRun];
+                        [newRun release];
+                        break;
+                }
+                ZAttributeRun *run = [_attributes objectAtIndex:first];
+                if (run.index == range.location) {
+                        break;
+                } else if (run.index > range.location) {
+                        ZAttributeRun *newRun = [[ZAttributeRun alloc] initWithIndex:range.location attributes:lastRun.attributes];
+                        [_attributes insertObject:newRun atIndex:first];
+                        [newRun release];
+                        break;
+                }
+                lastRun = run;
+        }
+        
+        if (((ZAttributeRun *)[_attributes lastObject]).index < NSMaxRange(range)) {
+                NSRange subrange = NSMakeRange(first, [_attributes count] - first);
+                if (NSMaxRange(range) < [_buffer length]) {
+                        ZAttributeRun *newRun = [[ZAttributeRun alloc] initWithIndex:NSMaxRange(range)
+                                                                                                                          attributes:(NSDictionary*)[(ZAttributeRun *)[_attributes lastObject] attributes]];
+                        [_attributes addObject:newRun];
+                        [newRun release];
+                }
+                return subrange;
+        } else {
+                // find the last run within and the first run after the range
+                NSUInteger lastIn = first, firstAfter = [_attributes count]-1;
+                while (firstAfter > lastIn + 1) {
+                        NSUInteger idx = (firstAfter + lastIn) / 2;
+                        ZAttributeRun *run = [_attributes objectAtIndex:idx];
+                        if (run.index < range.location) {
+                                lastIn = idx;
+                        } else if (run.index > range.location) {
+                                firstAfter = idx;
+                        } else {
+                                // this is definitively the first run after the range
+                                firstAfter = idx;
+                                break;
+                        }
+                }
+                if ([[_attributes objectAtIndex:firstAfter] index] > NSMaxRange(range)) {
+                        // the first after is too far after, insert another run!
+                        ZAttributeRun *newRun = [[ZAttributeRun alloc] initWithIndex:NSMaxRange(range)
+                                                                                                                          attributes:[(ZAttributeRun *)[_attributes objectAtIndex:firstAfter-1] attributes]];
+                        [_attributes insertObject:newRun atIndex:firstAfter];
+                        [newRun release];
+                }
+                return NSMakeRange(lastIn, firstAfter - lastIn);
+        }
+}
+
+- (void)cleanupAttributesInRange:(NSRange)range {
+        // expand the range to include one surrounding attribute on each side
+        if (range.location > 0) {
+                range.location -= 1;
+                range.length += 1;
+        }
+        if (NSMaxRange(range) < [_attributes count]) {
+                range.length += 1;
+        } else {
+                // make sure the range is capped to the attributes count
+                range.length = [_attributes count] - range.location;
+        }
+        if (range.length == 0) return;
+        ZAttributeRun *lastRun = [_attributes objectAtIndex:range.location];
+        for (NSUInteger i = range.location+1; i < NSMaxRange(range);) {
+                ZAttributeRun *run = [_attributes objectAtIndex:i];
+                if ([lastRun.attributes isEqualToDictionary:run.attributes]) {
+                        [_attributes removeObjectAtIndex:i];
+                        range.length -= 1;
+                } else {
+                        lastRun = run;
+                        i++;
+                }
+        }
+}
+
+- (void)offsetRunsInRange:(NSRange)range byOffset:(NSInteger)offset {
+        for (NSUInteger i = range.location; i < NSMaxRange(range); i++) {
+                ZAttributeRun *run = [_attributes objectAtIndex:i];
+                ZAttributeRun *newRun = [[ZAttributeRun alloc] initWithIndex:run.index + offset attributes:run.attributes];
+                [_attributes replaceObjectAtIndex:i withObject:newRun];
+                [newRun release];
+        }
+}
+@end
+
+@implementation ZAttributeRun
+@synthesize index = _index;
+@synthesize attributes = _attributes;
+
++ (id)attributeRunWithIndex:(NSUInteger)idx attributes:(NSDictionary *)attrs {
+        return [[[self alloc] initWithIndex:idx attributes:attrs] autorelease];
+}
+
+- (id)initWithIndex:(NSUInteger)idx attributes:(NSDictionary *)attrs {
+        NSParameterAssert(idx >= 0);
+        if ((self = [super init])) {
+                _index = idx;
+                if (attrs == nil) {
+                        _attributes = [[NSMutableDictionary alloc] init];
+                } else {
+                        _attributes = [attrs mutableCopy];
+                }
+        }
+        return self;
+}
+
+- (id)initWithCoder:(NSCoder *)decoder {
+        if ((self = [super init])) {
+                _index = [[decoder decodeObjectForKey:@"index"] unsignedIntegerValue];
+                _attributes = [[decoder decodeObjectForKey:@"attributes"] mutableCopy];
+        }
+        return self;
+}
+
+- (id)init {
+        return [self initWithIndex:0 attributes:[NSDictionary dictionary]];
+}
+
+- (id)copyWithZone:(NSZone *)zone {
+        return [[ZAttributeRun allocWithZone:zone] initWithIndex:_index attributes:_attributes];
+}
+
+- (void)encodeWithCoder:(NSCoder *)aCoder {
+        [aCoder encodeObject:[NSNumber numberWithUnsignedInteger:_index] forKey:@"index"];
+        [aCoder encodeObject:_attributes forKey:@"attributes"];
+}
+
+- (NSString *)description {
+        NSMutableArray *components = [NSMutableArray arrayWithCapacity:[_attributes count]];
+        for (id key in _attributes) {
+                [components addObject:[NSString stringWithFormat:@"%@=%@", key, [_attributes objectForKey:key]]];
+        }
+        return [NSString stringWithFormat:@"<%@: %p index=%lu attributes={%@}>",
+                        NSStringFromClass([self class]), self, (unsigned long)_index, [components componentsJoinedByString:@" "]];
+}
+
+- (BOOL)isEqual:(id)object {
+        if (![object isKindOfClass:[ZAttributeRun class]]) return NO;
+        ZAttributeRun *other = (ZAttributeRun *)object;
+        return _index == other->_index && [_attributes isEqualToDictionary:other->_attributes];
+}
+
+- (void)dealloc {
+        [_attributes release];
+        [super dealloc];
+}
+@end
+
+NSString * const ZFontAttributeName = @"ZFontAttributeName";
+NSString * const ZForegroundColorAttributeName = @"ZForegroundColorAttributeName";
+NSString * const ZBackgroundColorAttributeName = @"ZBackgroundColorAttributeName";
+NSString * const ZUnderlineStyleAttributeName = @"ZUnderlineStyleAttributeName";