Added Change Notifications to MPExpression, MPMutableExpression and MPFunction

Removed -beginEditing and -endEditing
Optimized -fixSymbols
Updated Project File

MathPad.xcodeproj/project.pbxproj

@@ -26,7 +26,6 @@
 		3BBBA35E1903FD3600824E74 /* MPRangePath.m in Sources */ = {isa = PBXBuildFile; fileRef = 3B87E35C1900933200259938 /* MPRangePath.m */; };
 		3BBBA35F1903FD3600824E74 /* MPRangePath.m in Sources */ = {isa = PBXBuildFile; fileRef = 3B87E35C1900933200259938 /* MPRangePath.m */; };
 		3BBBA3951905704200824E74 /* MPRangeTests.m in Sources */ = {isa = PBXBuildFile; fileRef = 3BBBA3941905704200824E74 /* MPRangeTests.m */; };
-		3BEB0F8119074815005699AB /* MPDisplayExtension.m in Sources */ = {isa = PBXBuildFile; fileRef = 3BEB0F8019074815005699AB /* MPDisplayExtension.m */; };
 		3BF9976F18DE623E009CF6C4 /* Cocoa.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 3BF9976E18DE623E009CF6C4 /* Cocoa.framework */; };
 		3BF9977918DE623E009CF6C4 /* InfoPlist.strings in Resources */ = {isa = PBXBuildFile; fileRef = 3BF9977718DE623E009CF6C4 /* InfoPlist.strings */; };
 		3BF9977B18DE623E009CF6C4 /* main.m in Sources */ = {isa = PBXBuildFile; fileRef = 3BF9977A18DE623E009CF6C4 /* main.m */; };
@@ -81,8 +80,6 @@
 		3BBBA35C1903F8A700824E74 /* NSObject+MPStringTest.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = "NSObject+MPStringTest.m"; sourceTree = "<group>"; };
 		3BBBA38419047FC900824E74 /* MPView.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = MPView.h; sourceTree = "<group>"; };
 		3BBBA3941905704200824E74 /* MPRangeTests.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPRangeTests.m; sourceTree = "<group>"; };
-		3BEB0F7F19074815005699AB /* MPDisplayExtension.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = MPDisplayExtension.h; sourceTree = "<group>"; };
-		3BEB0F8019074815005699AB /* MPDisplayExtension.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = MPDisplayExtension.m; sourceTree = "<group>"; };
 		3BF9976B18DE623E009CF6C4 /* MathPad.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = MathPad.app; sourceTree = BUILT_PRODUCTS_DIR; };
 		3BF9976E18DE623E009CF6C4 /* Cocoa.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = Cocoa.framework; path = System/Library/Frameworks/Cocoa.framework; sourceTree = SDKROOT; };
 		3BF9977118DE623E009CF6C4 /* AppKit.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = AppKit.framework; path = System/Library/Frameworks/AppKit.framework; sourceTree = SDKROOT; };
@@ -190,8 +187,6 @@
 		3BB09ED419071A140080A5ED /* Categories */ = {
 			isa = PBXGroup;
 			children = (
-				3BEB0F7F19074815005699AB /* MPDisplayExtension.h */,
-				3BEB0F8019074815005699AB /* MPDisplayExtension.m */,
 			);
 			name = Categories;
 			sourceTree = "<group>";
@@ -415,7 +410,6 @@
 			files = (
 				3BB09EE1190736160080A5ED /* MPSumFunctionLayout.m in Sources */,
 				3B87E3561900856F00259938 /* MPExpressionView.m in Sources */,
-				3BEB0F8119074815005699AB /* MPDisplayExtension.m in Sources */,
 				3BFCFF491905AAF30001FE33 /* NSTextStorage+MPSetContents.m in Sources */,
 				3BB09EC91906FD830080A5ED /* MPSumFunction.m in Sources */,
 				3BB09EB21905DE500080A5ED /* MPExpressionStorage.m in Sources */,

MathPad/MPExpression.h

@@ -6,7 +6,7 @@
 //  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
 //
 
-@class MPExpression, MPFunction;
+@class MPExpression, MPFunction, MPRangePath;
 
 extern NSString *MPAdditionOperator;
 extern NSString *MPSubtractionOperator;
@@ -86,14 +86,17 @@ extern NSString *MPDivisionOperator;
 
 @end
 
+@interface MPExpression (MPChangeNotificationExtension)
+
+- (void)symbolsChangedInRangePath:(MPRangePath *)rangePath replacementLength:(NSUInteger)length;
+
+@end
+
 @interface MPMutableExpression : MPExpression
 
 - (void)replaceSymbolsInRange:(NSRange)range
                   withSymbols:(NSArray *)symbols;
 
-- (void)beginEditing;
-- (void)endEditing;
-
 @end
 
 @interface MPMutableExpression (MPMutableExpressionExtensionMethods)

MathPad/MPExpression.m

@@ -9,9 +9,10 @@
 #import "MPExpression.h"
 #import "MPFunction.h"
 #import "MPException.h"
+#import "MPRangePath.h"
 
 #import "NSObject+MPStringTest.h"
-#import "NSIndexPath+MPRemoveFirstIndex.h"
+#import "NSIndexPath+MPReverseIndexPath.h"
 
 NSString *MPAdditionOperator = @"+";
 NSString *MPSubtractionOperator = @"-";
@@ -22,7 +23,6 @@ NSString *MPDivisionOperator = @"/";
 
 - (NSInteger)lengthOfSymbol:(id)symbol;
 - (void)validateSymbols:(NSArray *)symbols;
-- (NSArray *)fixedSymbols:(NSArray *)symbols;
 - (void)getSplitOffset:(out NSUInteger *)offset
        inSymbolAtIndex:(out NSUInteger *)symbolIndex
       forSplitLocation:(NSUInteger)loc;
@@ -53,7 +53,25 @@ NSString *MPDivisionOperator = @"/";
 
 - (void)fixSymbols
 {
-    _symbols = [self fixedSymbols:_symbols];
+    NSMutableArray *mutableSymbols = [_symbols mutableCopy];
+    for (NSInteger index = 0; index < mutableSymbols.count; index++) {
+        id next = index+1 < mutableSymbols.count ? mutableSymbols[index+1] : nil;
+        id current = mutableSymbols[index];
+        if ([current isString]) {
+            if ([current length] == 0) {
+                [mutableSymbols removeObjectAtIndex:index];
+                index--;
+            } else if ([next isString]) {
+                NSString *new = [NSString stringWithFormat:@"%@%@", current, next];
+                [mutableSymbols replaceObjectAtIndex:index withObject:new];
+                [mutableSymbols removeObjectAtIndex:index+1];
+                index--;
+            }
+        } else {
+            [(MPFunction *)current setParent:self];
+        }
+    }
+    _symbols = [mutableSymbols copy];
 }
 
 #pragma mark Primitive Methods
@@ -127,29 +145,6 @@ NSString *MPDivisionOperator = @"/";
     }
 }
 
-- (NSArray *)fixedSymbols:(NSArray *)symbols
-{
-    NSMutableArray *mutableSymbols = [symbols mutableCopy];
-    for (NSInteger index = 0; index < mutableSymbols.count; index++) {
-        id next = index+1 < mutableSymbols.count ? mutableSymbols[index+1] : nil;
-        id current = mutableSymbols[index];
-        if ([current isString]) {
-            if ([current length] == 0) {
-                [mutableSymbols removeObjectAtIndex:index];
-                index--;
-            } else if ([next isString]) {
-                NSString *new = [NSString stringWithFormat:@"%@%@", current, next];
-                [mutableSymbols replaceObjectAtIndex:index withObject:new];
-                [mutableSymbols removeObjectAtIndex:index+1];
-                index--;
-            }
-        } else {
-            [(MPFunction *)current setParent:self];
-        }
-    }
-    return [mutableSymbols copy];
-}
-
 - (void)getSplitOffset:(out NSUInteger *)offset
        inSymbolAtIndex:(out NSUInteger *)symbolIndex
       forSplitLocation:(NSUInteger)loc
@@ -420,9 +415,24 @@ NSString *MPDivisionOperator = @"/";
 
 @end
 
+@implementation MPExpression (MPChangeNotificationExtension)
+
+- (void)symbolsChangedInRangePath:(MPRangePath *)rangePath replacementLength:(NSUInteger)length
+{
+    if (!self.parent) {
+        return;
+    }
+    NSUInteger selfIndex = [self.parent indexOfChild:self];
+    NSIndexPath *newLocation = [rangePath.location indexPathByPrecedingIndex:selfIndex];
+    MPRangePath *newPath = [[MPRangePath alloc] initWithLocation:newLocation length:rangePath.length];
+    [self.parent symbolsChangedInRangePath:newPath replacementLength:length];
+}
+
+@end
+
 @implementation MPMutableExpression {
-    @protected
+    NSRange editedRange;
-    NSInteger _editCount;
+    NSRange replacementRange;
 }
 
 - (instancetype)initWithSymbols:(NSArray *)symbols
@@ -430,6 +440,8 @@ NSString *MPDivisionOperator = @"/";
     [self validateSymbols:symbols];
     self = [super initWithSymbols:nil];
     if (self) {
+        editedRange = NSMakeRange(0, 0);
+        replacementRange = NSMakeRange(0, 0);
         _symbols = [[NSMutableArray alloc] initWithArray:symbols
                                                copyItems:YES];
         [self fixSymbols];
@@ -439,7 +451,38 @@ NSString *MPDivisionOperator = @"/";
 
 - (void)fixSymbols
 {
-    _symbols = [[self fixedSymbols:_symbols] mutableCopy];
+    NSMutableArray *mutableSymbols = (NSMutableArray *)_symbols;
+    for (NSInteger index = 0; index < mutableSymbols.count; index++) {
+        id next = index+1 < mutableSymbols.count ? mutableSymbols[index+1] : nil;
+        id current = mutableSymbols[index];
+        if ([current isString]) {
+            if ([current length] == 0) {
+                [mutableSymbols removeObjectAtIndex:index];
+                if (index < replacementRange.location) {
+                    replacementRange.location--;
+                } else if (index < NSMaxRange(replacementRange)-1) {
+                    replacementRange.length--;
+                } else if (index == NSMaxRange(replacementRange)) {
+                    editedRange.length++;
+                }
+                index--;
+            } else if ([next isString]) {
+                NSString *new = [NSString stringWithFormat:@"%@%@", current, next];
+                [mutableSymbols replaceObjectAtIndex:index withObject:new];
+                [mutableSymbols removeObjectAtIndex:index+1];
+                if (index < replacementRange.location) {
+                    replacementRange.location--;
+                } else if (index < NSMaxRange(replacementRange)-1) {
+                    replacementRange.length--;
+                } else if (index == NSMaxRange(replacementRange)-1) {
+                    editedRange.length++;
+                }
+                index--;
+            }
+        } else {
+            [(MPFunction *)current setParent:self];
+        }
+    }
 }
 
 - (NSArray *)symbols
@@ -460,22 +503,27 @@ NSString *MPDivisionOperator = @"/";
     
     // Locate the position, split the symbols
     NSUInteger startIndex;
+    BOOL didSplitStart = NO;
     if ([self numberOfSymbols] == 0) {
         startIndex = 0;
     } else {
         [self splitSymbolsAtLocation:range.location
-                      insertionIndex:&startIndex];
+                      insertionIndex:&startIndex
+                            didSplit:&didSplitStart];
     }
     
     // Perform the deletion
-    if (range.length > 0) {
     NSUInteger endIndex;
+    BOOL didSplitEnd = NO;
     [self splitSymbolsAtLocation:NSMaxRange(range)
-                      insertionIndex:&endIndex];
+                  insertionIndex:&endIndex
+                        didSplit:&didSplitEnd];
+    if (range.length > 0) {
         NSMutableIndexSet *indexes = [[NSMutableIndexSet alloc] init];
         for (NSUInteger index = startIndex; index < endIndex; index++) {
             [indexes addIndex:index];
         }
+        // TODO: Replace with removeObjectsInRange:
         [(NSMutableArray *)_symbols removeObjectsAtIndexes:indexes];
     }
     
@@ -486,15 +534,20 @@ NSString *MPDivisionOperator = @"/";
                                      withObjectsFromArray:newSymbols];
     }
     
-    // Revalidate structure and invalidate length
+    // Invalidate length and revalidate structure
-    if (_editCount == 0) {
-        [self fixSymbols];
-    }
     _length = 0;
+    NSUInteger editingStart = startIndex - (didSplitStart?1:0);
+    NSUInteger editingLength = endIndex - startIndex + (didSplitStart?1:0) + (didSplitEnd?1:0);
+    editedRange = NSMakeRange(editingStart, editingLength);
+    replacementRange = NSMakeRange(startIndex, symbols.count);
+    [self fixSymbols];
+    MPRangePath *changePath = [[MPRangePath alloc] initWithRange:editedRange];
+    [self symbolsChangedInRangePath:changePath replacementLength:replacementRange.length];
 }
 
 - (void)splitSymbolsAtLocation:(NSUInteger)loc
                 insertionIndex:(out NSUInteger *)insertionIndex
+                      didSplit:(out BOOL *)flag;
 {
     NSUInteger splitSymbolIndex;
     NSUInteger splitOffset;
@@ -516,25 +569,10 @@ NSString *MPDivisionOperator = @"/";
         [(NSMutableArray *)_symbols insertObject:rightPart
                                          atIndex:splitSymbolIndex];
     }
+    *flag = splitOffset != 0;
     *insertionIndex = splitSymbolIndex;
 }
 
-- (void)beginEditing
-{
-    _editCount++;
-}
-
-- (void)endEditing
-{
-    if (_editCount == 0) {
-        return;
-    }
-    _editCount--;
-    if (_editCount == 0) {
-        [self fixSymbols];
-    }
-}
-
 @end
 
 @implementation MPMutableExpression (MPMutableExpressionExtensionMethods)

MathPad/MPFunction.h

@@ -6,7 +6,7 @@
 //  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
 //
 
-@class MPFunction, MPExpression;
+@class MPFunction, MPExpression, MPRangePath;
 
 @interface MPFunction : NSObject <NSCopying, NSCoding>
 
@@ -55,3 +55,9 @@
 - (NSUInteger)hash;
 
 @end
+
+@interface MPFunction (MPDisplayExtension)
+
+- (void)symbolsChangedInRangePath:(MPRangePath *)rangePath replacementLength:(NSUInteger)length;
+
+@end

MathPad/MPFunction.m

@@ -8,8 +8,9 @@
 
 #import "MPFunction.h"
 #import "MPExpression.h"
+#import "MPRangePath.h"
 
-#import "NSIndexPath+MPRemoveFirstIndex.h"
+#import "NSIndexPath+MPReverseIndexPath.h"
 
 @implementation MPFunction
 
@@ -157,3 +158,15 @@
 }
 
 @end
+
+@implementation MPFunction (MPDisplayExtension)
+
+- (void)symbolsChangedInRangePath:(MPRangePath *)rangePath replacementLength:(NSUInteger)length
+{
+    NSUInteger index = [self.parent indexOfSymbol:self];
+    NSIndexPath *newLocation = [rangePath.location indexPathByPrecedingIndex:index];
+    MPRangePath *newRangePath = [[MPRangePath alloc] initWithLocation:newLocation length:rangePath.length];
+    [self.parent symbolsChangedInRangePath:newRangePath replacementLength:length];
+}
+
+@end