TTExpressionEditorView.m

//
//  TTExpressionEditorView.m
//  Truth Tables
//
//  Created by Samuel Williams on 18/11/11.
//  Copyright (c) 2011 Orion Transfer Ltd. All rights reserved.
//

#import "TTExpressionEditorView.h"

#import "NSObject+BindingPropagation.h"

#import "TTParser.h"
#import "TTOperators.h"

enum {
	TTEnterKey = 36
};

@implementation TTExpressionEditorView

@synthesize operators = _operators, parser = _parser, expression = _expression;

- (void)awakeFromNib
{
	[self setOperators:[TTOperators standardOperators]];
}


- (void) updateExpressionValue:(NSString*)expression into:(NSMutableAttributedString*)buffer
{		
	// For some reason, when using this font, the vertical alignment becomes odd.
	NSFont * identifierFont = [[NSFontManager sharedFontManager] convertFont:self.font toHaveTrait:NSBoldFontMask];
	//NSFont * identifierFont = self.font;
	NSColor * operatorColor = [NSColor colorWithCalibratedHue:49.0 saturation:0.8 brightness:0.5 alpha:1.0];
	
	if (expression.length > 0) {
		TTParser * parser = [TTParser parse:expression withOperators:self.operators];
	
		[self setParser:parser];

		{			
			[buffer addAttribute:NSFontAttributeName value:self.font range:(NSRange){0, buffer.length}];
			[buffer removeAttribute:NSForegroundColorAttributeName range:(NSRange){0, buffer.length}];
			
			for (TTToken * token in self.parser.expressions) {
				NSRange textRange = {token.offset, token.text.length};
				
				if ([token isKindOfClass:[TTIdentifierToken class]]) {
					[buffer addAttribute:NSFontAttributeName value:identifierFont range:textRange];
				}
				
				if ([token isKindOfClass:[TTOperatorToken class]]) {
					[buffer addAttribute:NSForegroundColorAttributeName value:operatorColor range:textRange];
				}
			}
			
			for (TTParserError * error in self.parser.errors) {
				TTToken * token = error.token;
				
				NSRange textRange = {token.offset, token.text.length};
				
				//NSLog(@"Error at range: %@, %@", NSStringFromRange(textRange), error.message);
				
				if (textRange.location >= buffer.length || (textRange.location + textRange.length) > buffer.length) {
					//NSLog(@"Error out of range: %lu", buffer.length);
					continue;
				}
				
				[buffer addAttribute:NSForegroundColorAttributeName value:[NSColor redColor] range:textRange];
			}
		}
	} else {
		[self setParser:nil];
	}
}

- (void) updateEditorHighlighting: (NSString*)expression
{
	NSTextView * editor = (NSTextView*)[self currentEditor];	
	[self updateExpressionValue:self.stringValue into:editor.textStorage];
}

- (void) setExpression:(NSString *)expression
{
	if (self.expression == expression)
		return;
	
	if (expression && [self.expression isEqualToString:expression])
		return;
	
	[self willChangeValueForKey:@"expression"];
	
	_expression = expression;
	
	if (_expression) {
		[self setStringValue:_expression];
		NSMutableAttributedString * buffer = self.attributedStringValue.mutableCopy;
		[self updateExpressionValue:_expression into:buffer];
		
		[self setAllowsEditingTextAttributes:YES];
		[self setAttributedStringValue:buffer];
		[self setAllowsEditingTextAttributes:NO];
		
	}
		 
	//NSLog(@"Editor updated expression: %@", _expression);
	
	[self didChangeValueForKey:@"expression"];
}

- (BOOL)becomeFirstResponder
{
	BOOL result = [super becomeFirstResponder];
	
	[self updateEditorHighlighting:self.stringValue];
	
	return result;
}

- (void)textDidChange:(NSNotification *)aNotification
{
	[self updateEditorHighlighting:self.stringValue];
	
	[super textDidChange:aNotification];
}

- (void)textDidEndEditing:(NSNotification *)notification
{	
	if (self.parser && self.parser.errors.count == 0) {
		if (![self.stringValue isEqualToString:self.expression]) {
			// Update the model
			[self setExpression:self.stringValue];
		
			// Seems a bit weird...?
			[self propagateValue:self.stringValue forBinding:@"expression"];
		}
	}
	
	// This causes some issues for selection.
	//[super textDidEndEditing:notification];
}

- (BOOL)textShouldEndEditing:(NSText *)textObject
{
	NSEvent * event = [NSApp currentEvent];
	
	// The user pressed enter.
	if (event.type == NSKeyDown && event.keyCode == TTEnterKey) {
		if (self.parser.errors.count != 0) {
			return NO;
		}
	}
	
	return YES;
}

@end