This article describes how to support spell checking and grammer checking in a custom view. This view supports checking spelling using the Spelling pane and the Edit menu.

There aren’t a lot of examples of how to do this. The best one I could find was WebKit: http://trac.webkit.org/browser/trunk/WebKit/mac/WebCoreSupport/WebEditorClient.mm

–SaileshAgrawal

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#import <Cocoa/Cocoa.h>

@interface MyView : NSView { NSString *document; NSRange selection; NSInteger documentTag; NSArray *cachedSpellCheckResults; NSInteger misspellingIndex; NSInteger misspellingCount; } @end

#import “MyView.h”

static BOOL sContinuousSpellCheckingEnabled = YES; static BOOL sGrammarCheckingEnabled = YES;

@interface MyView ()

@property (retain) NSString *document; @property (retain) NSArray *cachedSpellCheckResults;

@end

@implementation MyView

@synthesize document; @synthesize cachedSpellCheckResults;

• (void)dealloc { [self setDocument:nil]; [self setCachedSpellCheckResults:nil]; [super dealloc]; }

• (void)setDocument:(NSString *)newDocument { [newDocument retain]; [document release]; document = newDocument; [self setCachedSpellCheckResults:nil]; }

• (NSArray *)spellCheckResults { if (!cachedSpellCheckResults) { NSTextCheckingType types = 0; if (sContinuousSpellCheckingEnabled) types |= NSTextCheckingTypeSpelling; if (sGrammarCheckingEnabled) types |= NSTextCheckingTypeGrammar; [self setCachedSpellCheckResults:[[NSSpellChecker sharedSpellChecker] checkString:document range:NSMakeRange(0, [document length]) types:types options:nil inSpellDocumentWithTag:documentTag orthography:NULL wordCount:NULL]]; } return cachedSpellCheckResults; }

• (void)awakeFromNib { [self setDocument:[NSMutableString stringWithString: @”I is a goode reader.\nHelllo worrld this is someething else.”]]; documentTag = [NSSpellChecker uniqueSpellDocumentTag]; }

• (BOOL)acceptsFirstResponder { return YES; }

• (BOOL)becomeFirstResponder { [self setNeedsDisplay:YES]; return YES; }

• (BOOL)resignFirstResponder { [self setNeedsDisplay:YES]; return YES; }

• (void)drawRect: (NSRect)rect { NSRect bounds = [self bounds]; [[NSColor lightGrayColor] set]; NSRectFill(bounds);

  if ([self window] firstResponder] isEqual:self]) { [[[[NSColor blueColor] set]; NSFrameRectWithWidth(bounds, 4); }

  NSDictionary *attributes = [NSDictionary dictionaryWithObjectsAndKeys: [NSFont systemFontOfSize:20], NSFontAttributeName, nil]; NSDictionary *spellingAttributes = [NSDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithInt:NSUnderlineStyleSingle | NSUnderlinePatternDot], NSUnderlineStyleAttributeName, [NSColor redColor], NSUnderlineColorAttributeName, nil]; NSDictionary *grammarAttributes = [NSDictionary dictionaryWithObjectsAndKeys: [NSNumber numberWithInt:NSUnderlineStyleSingle | NSUnderlinePatternDot], NSUnderlineStyleAttributeName, [NSColor greenColor], NSUnderlineColorAttributeName, nil];

  NSMutableAttributedString *text = [[[NSMutableAttributedString alloc] initWithString:document attributes:attributes] autorelease];

  for (NSTextCheckingResult *result in [self spellCheckResults]) { if ([result resultType] & NSTextCheckingTypeSpelling) { [text addAttributes:spellingAttributes range:[result range]]; } if ([result resultType] & NSTextCheckingTypeGrammar) { for (NSDictionary *details in [result grammarDetails]) { NSRange range = details objectForKey:[[NSGrammarRange] rangeValue]; range.location += [result range].location; [text addAttributes:grammarAttributes range:range]; } } }

  if (selection.length > 0) { NSDictionary *selAttributes = [NSDictionary dictionaryWithObjectsAndKeys: [NSColor selectedTextBackgroundColor], NSBackgroundColorAttributeName, nil]; [text addAttributes:selAttributes range:selection]; }

  NSRect textFrame; textFrame.size = [text size]; textFrame.origin.x = roundf((bounds.size.width - textFrame.size.width) / 2.0); textFrame.origin.y = roundf((bounds.size.height - textFrame.size.height) / 2.0); [text drawInRect:textFrame]; }

• (void)setSelection: (NSRange)range { selection = range; [self setNeedsDisplay:YES]; }

• (BOOL)advanceToNextMisspelling: (NSTextCheckingResult **)outResult details: (NSDictionary **)outDetails range: (NSRange *)outRange { NSUInteger findLocation = selection.location + selection.length; for (NSTextCheckingResult *result in [self spellCheckResults]) { if ([result resultType] & NSTextCheckingTypeSpelling) { if ([result range].location >= findLocation) { *outResult = result; *outDetails = nil; *outRange = [result range]; return YES; } } if ([result resultType] & NSTextCheckingTypeGrammar) { for (NSDictionary *details in [result grammarDetails]) { NSRange range = details objectForKey:[[NSGrammarRange] rangeValue]; range.location += [result range].location; if (range.location >= findLocation) { *outResult = result; *outDetails = details; *outRange = range; return YES; } } } }

  return NO; }

• (IBAction)checkSpelling:(id)sender { NSTextCheckingResult *result = nil; NSDictionary *details = nil; NSRange range; if ([self advanceToNextMisspelling:&result details:&details range:&range]) { if ([result resultType] & NSTextCheckingTypeSpelling) { [[NSSpellChecker sharedSpellChecker] updateSpellingPanelWithMisspelledWord:[document substringWithRange:range]]; } else if ([result resultType] & NSTextCheckingTypeGrammar) { [[NSSpellChecker sharedSpellChecker] updateSpellingPanelWithGrammarString:[document substringWithRange:range] detail:details]; } [self setSelection:range]; } else { [[NSSpellChecker sharedSpellChecker] updateSpellingPanelWithMisspelledWord:@””]; [self setSelection:NSMakeRange(0,0)]; } }

• (IBAction)changeSpelling:(id)sender { NSString* newWord = sender selectedCell] stringValue]; if (newWord != nil) { [self setDocument: [document stringByReplacingCharactersInRange:selection withString:newWord; NSRange range; range.location = selection.location + [newWord length]; range.length = 0; [self setSelection:range]; } }

• (IBAction)ignoreSpelling:(id)sender { NSString* wordToIgnore = [sender stringValue]; if (wordToIgnore != nil) { // TODO This doesn’t ignore grammar mistakes. [[NSSpellChecker sharedSpellChecker] ignoreWord:wordToIgnore inSpellDocumentWithTag:documentTag]; NSRange range; range.location = selection.location + [wordToIgnore length]; range.length = 0; [self setSelection:range]; [self setCachedSpellCheckResults:nil]; } }

• (IBAction)showGuessPanel:(id)sender { if (YES) { [[[NSSpellChecker sharedSpellChecker] spellingPanel] performSelectorOnMainThread:@selector(makeKeyAndOrderFront:) withObject:nil waitUntilDone:YES]; [self checkSpelling:nil]; } else { [[[NSSpellChecker sharedSpellChecker] spellingPanel] performSelectorOnMainThread:@selector(close) withObject:nil waitUntilDone:YES]; } }

• (IBAction)toggleContinuousSpellChecking:(id)sender { sContinuousSpellCheckingEnabled = !sContinuousSpellCheckingEnabled; [self setNeedsDisplay:YES]; }

• (IBAction)toggleGrammarChecking:(id)sender { sGrammarCheckingEnabled = !sGrammarCheckingEnabled; [self setNeedsDisplay:YES]; }

@end