Internal Redesign:

- Combined MPExpression and MPMutableExpression
- Abstracted children of MPExpression into MPExpressionElement protocol
- Abstracted most of MPExpressionLayout and MPFunctionLayout into common superclass MPLayout

MathPad/MPFunctionLayout.m

@@ -2,14 +2,13 @@
 //  MPFunctionLayout.m
 //  MathPad
 //
-//  Created by Kim Wittenburg on 22.04.14.
+//  Created by Kim Wittenburg on 07.08.14.
 //  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
 //
 
 #import "MPFunctionLayout.h"
-#import "MPExpressionLayout.h"
-#import "MPExpressionStorage.h"
 #import "MPFunction.h"
+#import "MPExpressionLayout.h"
 
 #import "MPSumFunction.h"
 #import "MPSumFunctionLayout.h"
@@ -17,114 +16,43 @@
 @implementation MPFunctionLayout
 
 #pragma mark Creation Methods
-
-+ (instancetype)functionLayoutForFunctionAtIndexPath:(NSIndexPath *)functionPath
-                                              parent:(MPExpressionLayout *)parent
++ (MPFunctionLayout *)functionLayoutForFunctionAtIndexPath:(NSIndexPath *)path
+                                                    parent:(MPExpressionLayout *)parent
 {
-    MPFunction *function = [parent.expressionStorage symbolAtIndexPath:functionPath];
+    MPFunction *function = [parent.expressionStorage elementAtIndexPath:path];
     Class class = [function class];
     if (class == [MPSumFunction class]) {
-        return [[MPSumFunctionLayout alloc] initWithFunctionPath:functionPath parent:parent];
+        return [[MPSumFunctionLayout alloc] initWithPath:path parent:parent];
     }
-    return nil;
-}
-
-- (id)initWithFunctionPath:(NSIndexPath *)functionPath
-                    parent:(MPExpressionLayout *)parent
-{
-    self = [super init];
-    if (self) {
-        _functionPath = functionPath;
-        _parent = parent;
-        _childCache = [[NSMutableArray alloc] init];
-    }
-    return self;
+    return [[self alloc] initWithPath:path parent:parent];
 }
 
 #pragma mark Properties
-
-- (MPExpressionStorage *)expressionStorage
-{
-    return self.parent.expressionStorage;
-}
-
 - (MPFunction *)function
 {
-    return [self.expressionStorage symbolAtIndexPath:self.functionPath];
-}
-
-- (NSLayoutManager *)layoutManager
-{
-    return self.expressionStorage.layoutManager;
-}
-
-- (NSTextContainer *)textContainer
-{
-    return self.expressionStorage.textContainer;
-}
-
-- (NSTextStorage *)textStorage
-{
-    return self.expressionStorage.textStorage;
+    return [self.expressionStorage elementAtIndexPath:self.path];
 }
 
 #pragma mark Cache Methods
-
-- (void)invalidate
+- (MPLayout *)childLayoutAtIndex:(NSUInteger)index
 {
-    _valid = NO;
-    [self.parent invalidate];
+    return [self cachableObjectForIndex:index generator:^id{
+        NSIndexPath *childPath = [self.path indexPathByAddingIndex:index];
+        MPExpressionLayout *layout = [[MPExpressionLayout alloc] initWithPath:childPath
+                                                                       parent:self];
+        return layout;
+    }];
 }
 
-- (void)editedChildAtIndex:(NSUInteger)index
+- (NSSize)sizeForChildAtIndex:(NSUInteger)index
 {
-    if ([self hasCacheForChildAtIndex:index]) {
-        _childCache[index] = [NSNull null];
-    }
-    [self invalidate];
+    MPLayout *childLayout = [self childLayoutAtIndex:index];
+    return [childLayout size];
 }
 
-- (BOOL)hasCacheForChildAtIndex:(NSUInteger)index
-{
-    if (index >= _childCache.count) {
-        return NO;
-    }
-    return _childCache[index] != [NSNull null];
-}
-
-- (MPExpressionLayout *)expressionLayoutForChildAtIndex:(NSUInteger)index
-{
-    if ([self hasCacheForChildAtIndex:index]) {
-        return _childCache[index];
-    }
-    while (index >= _childCache.count) {
-        [_childCache addObject:[NSNull null]];
-    }
-    MPExpressionLayout *expressionLayout = [[MPExpressionLayout alloc] initWithExpressionPath:[self.functionPath indexPathByAddingIndex:index] parent:self];
-    _childCache[index] = expressionLayout;
-    return expressionLayout;
-}
-
-#pragma mark Size Calculation Methods
-
-- (NSSize)sizeOfFunction
-{
-    if (!_valid) {
-        _cachedSize = [self calculateSize];
-        _valid = YES;
-    }
-    return _cachedSize;
-}
-
-- (NSSize)calculateSize
-{
-    return NSMakeSize(0, 0);
-}
-
-#pragma mark Drawing Methods
-
-- (void)drawFunctionAtPoint:(NSPoint)point
+- (NSBezierPath *)generateBezierPath
 {
+    return [NSBezierPath bezierPath];
 }
 
 @end