Added MPExpressionLayout, MPFunctionLayout and MPExpressionStorage as Rendering System for Expressions

MathPad/MPExpressionStorage.m

@@ -0,0 +1,60 @@
+//
+//  MPExpressionStorage.m
+//  MathPad
+//
+//  Created by Kim Wittenburg on 22.04.14.
+//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
+//
+
+#import "MPExpressionStorage.h"
+#import "MPExpressionLayout.h"
+
+@interface MPExpressionStorage ()
+@property (nonatomic, strong) NSLayoutManager *layoutManager;
+@property (nonatomic, strong) NSTextContainer *textContainer;
+@property (nonatomic, strong) NSTextStorage *textStorage;
+@end
+
+@implementation MPExpressionStorage
+
+- (instancetype)initWithSymbols:(NSArray *)symbols
+{
+    self = [super initWithSymbols:symbols];
+    if (self) {
+        _expressionLayout = [[MPExpressionLayout alloc] initRootLayoutWithExpressionStorage:self];
+    }
+    return self;
+}
+
+- (NSLayoutManager *)layoutManager
+{
+    [self ensureTextSystemObjects];
+    return _layoutManager;
+}
+
+- (NSTextContainer *)textContainer
+{
+    [self ensureTextSystemObjects];
+    return _textContainer;
+}
+
+- (NSTextStorage *)textStorage
+{
+    [self ensureTextSystemObjects];
+    return _textStorage;
+}
+
+- (void)ensureTextSystemObjects
+{
+    if (_layoutManager == nil || _textContainer == nil || _textStorage == nil) {
+        _textStorage = [[NSTextStorage alloc] init];
+        NSTextContainer *textContainer = [[NSTextContainer alloc] initWithContainerSize:NSMakeSize(CGFLOAT_MAX, CGFLOAT_MAX)];
+        NSLayoutManager *layoutManager = [[NSLayoutManager alloc] init];
+        [layoutManager addTextContainer:textContainer];
+        [_textStorage addLayoutManager:layoutManager];
+        _textContainer = textContainer;
+        _layoutManager = layoutManager;
+    }
+}
+
+@end