Added Lots of Documentation

Added some nice to haves
Improved and Unified General Code Layout

MathKit/MPExpressionView.m

@@ -8,26 +8,25 @@
 
 #import "MPExpressionView.h"
 
-#import "MPExpression.h"
-#import "MPExpression.h"
-#import "MPParsedExpression.h"
-
-#import "MPPowerFunction.h"
-#import "MPParenthesisFunction.h"
-#import "MPFractionFunction.h"
-
-#import "MPToken.h"
-#import "MPRangePath.h"
-#import "MPMathRules.h"
-
 #import "MPExpressionStorage.h"
 #import "MPExpressionLayout.h"
-#import "MPFunctionLayout.h"
 
 #import "MPFunctionsViewController.h"
 
+#import "MPFunctionLayout.h"
+#import "MPFractionFunction.h"
+#import "MPParenthesisFunction.h"
+#import "MPPowerFunction.h"
+
+#import "MPParsedExpression.h"
+#import "MPMathRules.h"
+#import "MPToken.h"
+
+#import "MPRangePath.h"
 #import "NSIndexPath+MPAdditions.h"
 
+
+
 @interface MPExpressionView ()
 
 @property (nonatomic, strong) NSButton *functionsButton;
@@ -58,6 +57,7 @@
 
 
 @interface MPExpressionView (MPSelectionHelper)
+
 - (void)restartCaretTimer;
 - (void)updateCaret:(NSTimer *)timer;
 
@@ -101,6 +101,7 @@
     [self updateCaret:self.caretTimer];
 }
 
+
 - (void)updateCaret:(NSTimer *)timer
 {
     self.caretVisible = !self.caretVisible;
@@ -111,6 +112,7 @@
     [self setNeedsDisplayInRect:updatedRect];
 }
 
+
 - (NSRect)selectionRect
 {
     NSRect selectionRect = [self.expressionStorage.rootLayout boundingRectForRangePath:self.selection];
@@ -120,6 +122,7 @@
     return selectionRect;
 }
 
+
 - (NSIndexPath *)selectionToTheRightOf:(NSIndexPath *)selectionPath
                   byExtendingSelection:(BOOL)extendingSelection
                            selectWords:(BOOL)selectWords
@@ -186,6 +189,7 @@
     return [selectionPath indexPathByReplacingLastIndexWithIndex:locationInTarget];
 }
 
+
 - (NSIndexPath *)selectionToTheLeftOf:(NSIndexPath *)selectionPath
                  byExtendingSelection:(BOOL)extendingSelection
                           selectWords:(BOOL)selectWords
@@ -257,6 +261,7 @@
     return [selectionPath indexPathByReplacingLastIndexWithIndex:locationInTarget];
 }
 
+
 - (MPRangePath *)rangePathEnclosingAnchorPath:(NSIndexPath *)anchorPath
                              newSelectionPath:(NSIndexPath *)newSelectionPath
 {
@@ -312,9 +317,13 @@
 
 
 #pragma mark -
+
+
 @implementation MPExpressionView
 
 #pragma mark Creation Methods
+
+
 - (id)initWithFrame:(NSRect)frame
 {
     self = [super initWithFrame:frame];
@@ -324,6 +333,7 @@
     return self;
 }
 
+
 - (id)initWithCoder:(NSCoder *)aDecoder
 {
     self = [super initWithCoder:aDecoder];
@@ -333,6 +343,7 @@
     return self;
 }
 
+
 - (void)initializeExpressionView
 {
     // Setup the Expression Storage
@@ -348,6 +359,7 @@
     [self restartCaretTimer];
 }
 
+
 - (void)initializeButtons
 {
     NSButton *functionsButton = self.functionsButton;
@@ -368,6 +380,7 @@
                                                       constant:0]];
 }
 
+
 - (void)initializeErrorsViews
 {
     
@@ -394,34 +407,42 @@
                                                                    views:variableBindings]];
 }
 
+
 #pragma mark - NSView Configuration
+
+
 - (BOOL)acceptsFirstResponder
 {
     return YES;
 }
 
+
 - (BOOL)canBecomeKeyView
 {
     return YES;
 }
 
+
 - (BOOL)isOpaque
 {
     return YES;
 }
 
+
 - (void)resetCursorRects
 {
     [self addCursorRect:self.bounds
                  cursor:[NSCursor IBeamCursor]];
 }
 
+
 - (BOOL)becomeFirstResponder
 {
     [self restartCaretTimer];
     return [super becomeFirstResponder];
 }
 
+
 - (BOOL)resignFirstResponder
 {
     [self.caretTimer invalidate];
@@ -430,12 +451,14 @@
     return [super resignFirstResponder];
 }
 
+
 - (void)setFrame:(NSRect)frameRect
 {
     [self setNeedsLayout:YES];
     [super setFrame:frameRect];
 }
 
+
 - (NSSize)intrinsicContentSize
 {
     NSSize size = self.expressionStorage.rootLayout.bounds.size;
@@ -443,7 +466,10 @@
     return size;
 }
 
+
 #pragma mark - Properties
+
+
 - (void)setExpressionStorage:(MPExpressionStorage *)expressionStorage
 {
     _expressionStorage.expressionView = nil;
@@ -452,6 +478,7 @@
     [self invalidateIntrinsicContentSize];
 }
 
+
 - (void)setSelection:(MPRangePath *)selection
 {
     _selection = selection;
@@ -459,6 +486,7 @@
     self.needsDisplay = YES;
 }
 
+
 - (void)setSyntaxErrors:(NSArray *)syntaxErrors
 {
     _syntaxErrors = syntaxErrors;
@@ -491,12 +519,14 @@
     }
 }
 
+
 - (void)setMathError:(NSError *)mathError
 {
     _mathError = mathError;
     self.mathErrorTextField.stringValue = mathError != nil ? mathError.localizedDescription : @"";
 }
 
+
 - (NSButton *)functionsButton
 {
     if (!_functionsButton) {
@@ -520,6 +550,7 @@
     return _functionsButton;
 }
 
+
 - (NSPopUpButton *)syntaxErrorsPopUpButton
 {
     if (!_syntaxErrorsPopUpButton) {
@@ -539,6 +570,7 @@
     return _syntaxErrorsPopUpButton;
 }
 
+
 - (NSTextField *)mathErrorTextField
 {
     if (!_mathErrorTextField) {
@@ -555,6 +587,7 @@
     return _mathErrorTextField;
 }
 
+
 - (void)didSelectError:(NSPopUpButton *)sender
 {
     NSError *error = self.syntaxErrors[sender.indexOfSelectedItem-1];
@@ -564,7 +597,10 @@
     self.selection = MPMakeRangePath(pathToExpression, errorRange.length);
 }
 
+
 #pragma mark - Mouse Event Handling
+
+
 - (void)mouseDown:(NSEvent *)theEvent
 {
     NSPoint pointInView = [self convertPoint:theEvent.locationInWindow
@@ -577,6 +613,7 @@
     self.selection = MPMakeRangePath(selectionPath, 0);
 }
 
+
 - (void)mouseDragged:(NSEvent *)theEvent
 {
     NSPoint pointInView = [self convertPoint:theEvent.locationInWindow
@@ -590,7 +627,10 @@
                                        newSelectionPath:mouseSelectionPath];
 }
 
+
 #pragma mark Key Event Handling
+
+
 - (void)keyDown:(NSEvent *)theEvent
 {
     NSString *characters = theEvent.characters;
@@ -617,6 +657,15 @@
     [allowedCharacters addCharactersInString:[NSString stringWithFormat:@"+-*= !%@", decimalSeparator]];
     
     if (characters.length == 1 && [characters stringByTrimmingCharactersInSet:allowedCharacters].length == 0) {
+        if ([characters isEqualTo:@"i"]) {
+            if (self.selection.location.lastIndex > 0) {
+                id<MPExpressionElement> symbol = [self.expressionStorage symbolAtIndex:self.selection.location.lastIndex-1];
+                if ([symbol isEqual:@"p"]) {
+                    self.selection = MPMakeRangePath([self.selection.location indexPathByDecrementingLastIndex], self.selection.length+1);
+                    characters = @"π";
+                }
+            }
+        }
         if ([characters isEqualToString:@"*"]) {
             characters = @"⋅";
         }
@@ -629,22 +678,28 @@
     }
 }
 
+
 #pragma mark - Actions
+
+
 - (void)switchToDegrees:(id)sender
 {
     [MPMathRules sharedRules].isUsingDegrees = YES;
 }
 
+
 - (void)switchToRadians:(id)sender
 {
     [MPMathRules sharedRules].isUsingDegrees = NO;
 }
 
+
 - (void)switchRadiansDegrees:(id)sender
 {
     [MPMathRules sharedRules].isUsingDegrees = ![MPMathRules sharedRules].isUsingDegrees;
 }
 
+
 - (IBAction)toggleFunctionsPopover:(id)sender
 {
     if (self.functionsPopover == nil || self.functionsViewController == nil) {
@@ -663,6 +718,7 @@
     }
 }
 
+
 - (void)insertFunction:(MPFunction *)function
 {
     [self.functionsPopover close];
@@ -678,8 +734,10 @@
     self.selection = MPMakeRangePath([[functionPath indexPathByAddingIndex:functionLayout.indexOfLeadingChild] indexPathByAddingIndex:0], 0);
 }
 
+
 #pragma mark Editing Actions
 
+
 - (void)insertParenthesisFunction:(id)sender
 {
     MPExpression *selectedElementsExpression = [self.expressionStorage subexpressionWithRangePath:self.selection
@@ -698,6 +756,7 @@
     self.selection = MPMakeRangePath([[functionPath indexPathByAddingIndex:0] indexPathByAddingIndex:0], self.selection.length);
 }
 
+
 - (void)insertClosingParenthesis
 {
     if (self.selection.length > 0) {
@@ -721,6 +780,7 @@
     }
 }
 
+
 - (void)insertPowerFunction
 {
     MPExpression *selectedElementsExpression = [self.expressionStorage subexpressionWithRangePath:self.selection
@@ -739,6 +799,7 @@
     self.selection = MPMakeRangePath([[functionPath indexPathByAddingIndex:0] indexPathByAddingIndex:0], self.selection.length);
 }
 
+
 - (void)insertFractionFunction
 {
     if (self.selection.length == 0) {
@@ -792,6 +853,7 @@
     }
 }
 
+
 - (void)insertNewline:(id)sender
 {
     if (self.target && self.action) {
@@ -801,6 +863,7 @@
     }
 }
 
+
 - (void)deleteBackward:(id)sender
 {
     if (self.selection.length > 0) {
@@ -853,6 +916,7 @@
     }
 }
 
+
 - (void)delete:(id)sender
 {
     [self.expressionStorage replaceItemsInRangePath:self.selection
@@ -861,8 +925,10 @@
     self.selection = MPMakeRangePath(self.selection.location, 0);
 }
 
+
 #pragma mark Selection Actions
 
+
 - (void)moveRight:(id)sender
 {
     if (self.selection.length > 0) {
@@ -875,6 +941,7 @@
     }
 }
 
+
 - (void)moveLeft:(id)sender
 {
     if (self.selection.length > 0) {
@@ -887,6 +954,7 @@
     }
 }
 
+
 - (void)moveWordRight:(id)sender
 {
     NSIndexPath *location = self.selection.maxRangePath;
@@ -896,6 +964,7 @@
     self.selection = MPMakeRangePath(newSelectionLocation, 0);
 }
 
+
 - (void)moveWordLeft:(id)sender
 {
     NSIndexPath *location = self.selection.location;
@@ -905,17 +974,20 @@
     self.selection = MPMakeRangePath(newSelectionLocation, 0);
 }
 
+
 - (void)moveToBeginningOfLine:(id)sender
 {
     self.selection = MPMakeRangePath([self.selection.location indexPathByReplacingLastIndexWithIndex:0], 0);
 }
 
+
 - (void)moveToEndOfLine:(id)sender
 {
     MPExpression *targetExpression = [self.expressionStorage elementAtIndexPath:[self.selection.location indexPathByRemovingLastIndex]];
     self.selection = MPMakeRangePath([self.selection.location indexPathByReplacingLastIndexWithIndex:targetExpression.countSymbols], 0);
 }
 
+
 - (void)moveLeftAndModifySelection:(id)sender
 {
     if (self.selection.length == 0) {
@@ -935,6 +1007,7 @@
     self.selection = [self rangePathEnclosingAnchorPath:maxLocation newSelectionPath:location];
 }
 
+
 - (void)moveRightAndModifySelection:(id)sender
 {
     if (self.selection.length == 0) {
@@ -955,6 +1028,7 @@
     self.selection = MPMakeRangePath(location, maxLocation.lastIndex-location.lastIndex);
 }
 
+
 - (void)moveWordRightAndModifySelection:(id)sender
 {
     if (self.selection.length == 0) {
@@ -977,6 +1051,7 @@
     self.selection = MPMakeRangePath(location, maxLocation.lastIndex-location.lastIndex);
 }
 
+
 - (void)moveWordLeftAndModifySelection:(id)sender
 {
     if (self.selection.length == 0) {
@@ -999,6 +1074,7 @@
     self.selection = MPMakeRangePath(location, maxLocation.lastIndex-location.lastIndex);
 }
 
+
 - (void)moveUp:(id)sender
 {
     NSIndexPath *targetExpressionPath = [self.selection.location indexPathByRemovingLastIndex];
@@ -1011,6 +1087,7 @@
     }
 }
 
+
 - (void)moveDown:(id)sender
 {
     NSIndexPath *targetExpressionPath = [self.selection.location indexPathByRemovingLastIndex];
@@ -1023,13 +1100,17 @@
     }
 }
 
+
 - (void)selectAll:(id)sender
 {
     NSIndexPath *location = [NSIndexPath indexPathWithIndex:0];
     self.selection = MPMakeRangePath(location, self.expressionStorage.countSymbols);
 }
 
+
 #pragma mark Drawing Methods
+
+
 - (void)drawRect:(NSRect)dirtyRect
 {
     // Draw the background
@@ -1066,6 +1147,7 @@
 
 #pragma mark - User Interface Validations
 
+
 - (BOOL)validateUserInterfaceItem:(id<NSValidatedUserInterfaceItem>)anItem
 {
     BOOL degrees = [MPMathRules sharedRules].isUsingDegrees;