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/*
 *  R.app : a Cocoa front end to: "R A Computer Language for Statistical Data Analysis"
 *  
 *  R.app Copyright notes:
 *                     Copyright (C) 2004-12  The R Foundation
 *                     written by Stefano M. Iacus and Simon Urbanek
 *
 *                  
 *  R Copyright notes:
 *                     Copyright (C) 1995-1996   Robert Gentleman and Ross Ihaka
 *                     Copyright (C) 1998-2001   The R Development Core Team
 *                     Copyright (C) 2002-2004   The R Foundation
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  A copy of the GNU General Public License is available via WWW at
 *  http://www.gnu.org/copyleft/gpl.html.  You can also obtain it by
 *  writing to the Free Software Foundation, Inc., 59 Temple Place,
 *  Suite 330, Boston, MA  02111-1307  USA.
 *
 *  RScriptEditorTextStorage.m
 *
 *  Created by Hans-J. Bibiko on 01/03/2012.
 *
 */

#import "RScriptEditorTextStorage.h"
#import "RScriptEditorTypesetter.h"
#import "FoldingSignTextAttachmentCell.h"
#import "PreferenceKeys.h"

@implementation RScriptEditorTextStorage

@synthesize lineFoldingEnabled = _lineFoldingEnabled;

static NSTextAttachment *sharedAttachment = nil;
static SEL _getSel;
static SEL _setSel;
static SEL _strSel;
static SEL _replSel;
static SEL _editSel;

+ (void)initialize
{

    if ([self class] == [RScriptEditorTextStorage class]) {
        FoldingSignTextAttachmentCell *cell = [[FoldingSignTextAttachmentCell alloc] initImageCell:nil];
        sharedAttachment = [[NSTextAttachment alloc] init];
        [sharedAttachment setAttachmentCell:cell];
        [cell release];
        _getSel  = @selector(attributesAtIndex:effectiveRange:);
        _setSel  = @selector(setAttributes:range:);
        _strSel  = @selector(string);
        _replSel = @selector(replaceCharactersInRange:withString:);
        _editSel = @selector(edited:range:changeInLength:);
        _lineFoldingEnabled = NO;
    }
}

+ (NSTextAttachment *)attachment
{
    return sharedAttachment;
}

- (id)init
{
    self = [super init];

    if (self != nil) {
        _attributedString = [[NSTextStorage alloc] init];
        _getImp  = [_attributedString methodForSelector:_getSel];
        _setImp  = [_attributedString methodForSelector:_setSel];
        _strImp  = [_attributedString methodForSelector:_strSel];
        _replImp = [_attributedString methodForSelector:_replSel];
        _editImp = [_attributedString methodForSelector:_editSel];
    }

    return self;
}

- (void)dealloc
{
    [[NSNotificationCenter defaultCenter] removeObserver:self];
    [_attributedString release];
    if(sharedAttachment) [sharedAttachment release];
    [super dealloc];
}

// NSAttributedString primitives
- (NSString *)string
{ 
    return (*_strImp)(_attributedString, _strSel);
}

- (NSDictionary *)attributesAtIndex:(NSUInteger)location effectiveRange:(NSRangePointer)range
{

    NSDictionary *attributes = (*_getImp)(_attributedString, _getSel, location, range);

    if(!_lineFoldingEnabled) return attributes;

    id value;
    NSRange effectiveRange;

    value = [attributes objectForKey:foldingAttributeName];
    if (value && [value boolValue]) {
        [_attributedString attribute:foldingAttributeName atIndex:location longestEffectiveRange:&effectiveRange inRange:NSMakeRange(0, [_attributedString length])];

        // We adds NSAttachmentAttributeName if in lineFoldingAttributeName
        if (location == effectiveRange.location) { // beginning of a folded range
            NSMutableDictionary *dict = [attributes mutableCopyWithZone:NULL];
            [dict setObject:sharedAttachment forKey:NSAttachmentAttributeName];
            attributes = [dict autorelease];
            effectiveRange.length = 1;
        } else {
            ++(effectiveRange.location); --(effectiveRange.length);
        }
        if (range) *range = effectiveRange;
    }

    return attributes;

}

// NSMutableAttributedString primitives
- (void)replaceCharactersInRange:(NSRange)range withString:(NSString *)str
{
    (*_replImp)(_attributedString, _replSel, range, str);
    (*_editImp)(self, _editSel, NSTextStorageEditedCharacters, range, [str length] - range.length);
}

- (void)setAttributes:(NSDictionary *)attrs range:(NSRange)range
{
    (*_setImp)(_attributedString, _setSel, attrs, range);
    (*_editImp)(self, _editSel, NSTextStorageEditedAttributes, range, 0);
}

// Attribute Fixing Overrides
/*
- (void)fixAttributesInRange:(NSRange)range
{
    [super fixAttributesInRange:range];

    if(NSMaxRange(range) == 0) return;

    //  we want to avoid extending to the last paragraph separator
    NSDictionary *attributeDict;
    NSRange effectiveRange = { 0, 0 };
    NSUInteger idx = range.location;
    while (NSMaxRange(effectiveRange) < NSMaxRange(range)) {
        attributeDict = [_attributedString attributesAtIndex:idx
                                   longestEffectiveRange:&effectiveRange
                                                 inRange:range];
        id value = [attributeDict objectForKey:foldingAttributeName];
        if (value && effectiveRange.length) {
            NSUInteger paragraphStart, paragraphEnd, contentsEnd;
            [[self string] getParagraphStart:&paragraphStart end:&paragraphEnd contentsEnd:&contentsEnd forRange:range];
            if ((NSMaxRange(range) == paragraphEnd) && (contentsEnd < paragraphEnd)) {
                [self removeAttribute:foldingAttributeName range:NSMakeRange(contentsEnd, paragraphEnd - contentsEnd)];
            }
        }
        idx = NSMaxRange(effectiveRange);
    }

    // 10.6 implementation
    // [self enumerateAttribute:lineFoldingAttributeName inRange:range options:0 usingBlock:^(id value, NSRange range, BOOL *stop) {
    //  if (value && (range.length > 1)) {
    //      NSUInteger paragraphStart, paragraphEnd, contentsEnd;
    //      [[self string] getParagraphStart:&paragraphStart end:&paragraphEnd contentsEnd:&contentsEnd forRange:range];
    //      if ((NSMaxRange(range) == paragraphEnd) && (contentsEnd < paragraphEnd)) {
    //          [self removeAttribute:lineFoldingAttributeName range:NSMakeRange(contentsEnd, paragraphEnd - contentsEnd)];
    //      }
    //  }
    // }];
}
*/

@end