Improved Selection Algorithm

MathPad/MPExpressionView.m

@@ -6,8 +6,6 @@
 //  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
 //
 
-#warning X-Origin is not working yet
-
 #import "MPExpressionView.h"
 #import "MPExpressionStorage.h"
 #import "MPExpressionLayout.h"
@@ -18,6 +16,8 @@
 
 #import "MPSumFunction.h"
 
+
+
 @interface MPExpressionView ()
 
 @property (nonatomic, weak) NSButton *functionsButton;
@@ -28,23 +28,37 @@
 
 @property (nonatomic, getter = isSelectionModifyingStart) BOOL selectionModifyingStart;
 
+@property (nonatomic, strong) NSIndexPath *mouseAnchor;
+
 @end
 
+
+
 @interface MPExpressionView (MPDrawing)
 
 - (NSPoint)expressionOrigin;
 
 @end
 
+
+
 @interface MPExpressionView (MPSelection)
 - (void)restartCaretTimer;
 - (void)updateCaret:(NSTimer *)timer;
 
 - (NSRect)selectionRect;
 
-- (void)selectRangePathWithLocation:(NSIndexPath *)location length:(NSUInteger)length;
+- (NSIndexPath *)selectionToTheRightOf:(NSIndexPath *)selection
+                           selectWords:(BOOL)flag;
+- (NSIndexPath *)selectionToTheLeftOf:(NSIndexPath *)selection
+                          selectWords:(BOOL)flag;
+
+- (MPRangePath *)rangePathEnclosingAnchor:(NSIndexPath *)anchor
+                             newSelection:(NSIndexPath *)newSelection;
 @end
 
+
+
 @implementation MPExpressionView (MPDrawing)
 
 - (NSPoint)expressionOrigin
@@ -56,6 +70,8 @@
 
 @end
 
+
+
 @implementation MPExpressionView (MPSelection)
 
 - (void)restartCaretTimer
@@ -85,22 +101,64 @@
     return selectionRect;
 }
 
-- (void)selectRangePathWithLocation:(NSIndexPath *)location length:(NSUInteger)length
+- (NSIndexPath *)selectionToTheRightOf:(NSIndexPath *)selection
+                           selectWords:(BOOL)flag
 {
-    MPExpression *targetExpression = [self.expressionStorage elementAtIndexPath:[location indexPathByRemovingLastIndex]];
+    MPExpression *targetExpression = [self.expressionStorage elementAtIndexPath:[selection indexPathByRemovingLastIndex]];
-    NSUInteger locationIndex = location.lastIndex;
+    NSUInteger locationInTarget = selection.lastIndex;
-    if (locationIndex > targetExpression.length) {
+    NSUInteger locationInElement;
-        locationIndex = targetExpression.length;
+    NSUInteger targetElementIndex = [targetExpression indexOfElementAtSymbolLocation:locationInTarget
+                                                                              offset:&locationInElement];
+    id<MPExpressionElement> targetElement;
+    if (targetElementIndex < targetExpression.numberOfElements) {
+        targetElement = [targetExpression elementAtIndex:targetElementIndex];
     }
-    NSUInteger lastSelectedIndex = location.lastIndex + length;
+    if (locationInElement == 0 && !flag) {
-    if (lastSelectedIndex > targetExpression.length) {
+        NSLog(@"Move to next");
-        lastSelectedIndex = targetExpression.length;
+        // Move to next element
+    } else if (locationInTarget < targetExpression.length) {
+        if (flag) {
+            locationInTarget = [targetExpression locationOfElementAtIndex:targetElementIndex+1];
+        } else {
+            locationInTarget++;
+        }
     }
-    self.selection = MPMakeRangePath([location indexPathByReplacingLastIndexWithIndex:locationIndex],lastSelectedIndex - locationIndex);
+    return [selection indexPathByReplacingLastIndexWithIndex:locationInTarget];
+}
+
+- (NSIndexPath *)selectionToTheLeftOf:(NSIndexPath *)selection
+                          selectWords:(BOOL)flag
+{
+    MPExpression *targetExpression = [self.expressionStorage elementAtIndexPath:[selection indexPathByRemovingLastIndex]];
+    NSUInteger locationInTarget = selection.lastIndex;
+    NSUInteger locationInElement;
+    NSUInteger targetElementIndex = [targetExpression indexOfElementAtSymbolLocation:locationInTarget
+                                                                              offset:&locationInElement];
+    if (locationInElement == 0 && !flag) {
+        // Move to previous element
+    } else if (locationInTarget > 0) {
+        if (flag) {
+            if (locationInElement == 0) {
+                targetElementIndex--;
+            }
+            locationInTarget = [targetExpression locationOfElementAtIndex:targetElementIndex];
+        } else {
+            locationInTarget--;
+        }
+    }
+    return [selection indexPathByReplacingLastIndexWithIndex:locationInTarget];
+}
+
+- (MPRangePath *)rangePathEnclosingAnchor:(NSIndexPath *)anchor
+                             newSelection:(NSIndexPath *)newSelection
+{
+    
 }
 
 @end
 
+
+
 @implementation MPExpressionView
 
 #pragma mark Creation Methods
@@ -125,7 +183,7 @@
 - (void)initializeExpressionView
 {
     // Setup the Expression Storage
-    MPExpressionStorage *expressionStorage = [[MPExpressionStorage alloc] initWithElements:@[@"12345", [[MPSumFunction alloc] init], [[MPSumFunction alloc] init]]];
+    MPExpressionStorage *expressionStorage = [[MPExpressionStorage alloc] initWithElements:@[@"12345", [[MPSumFunction alloc] init]]];
     expressionStorage.expressionView = self;
     _expressionStorage = expressionStorage;
     
@@ -207,7 +265,7 @@
 {
     NSString *characters = theEvent.characters;
     NSMutableCharacterSet *allowedCharacters = [NSMutableCharacterSet alphanumericCharacterSet];
-    [allowedCharacters addCharactersInString:@"+-*/= "];
+    [allowedCharacters addCharactersInString:@"+-*= "];
     if (characters.length == 1 && [characters stringByTrimmingCharactersInSet:allowedCharacters].length == 0) {
         MPExpression *targetExpression = [self.expressionStorage elementAtIndexPath:[self.selection.location indexPathByRemovingLastIndex]];
         [targetExpression replaceSymbolsInRange:self.selection.rangeAtLastIndex withElements:@[characters]];
@@ -222,9 +280,9 @@
     if (self.selection.length > 0) {
         self.selection = MPMakeRangePath(self.selection.maxRangePath, 0);
     } else {
-        NSIndexPath *newSelectionLocation = [self.selection.location indexPathByIncrementingLastIndex];
+        NSIndexPath *newSelectionLocation = [self selectionToTheRightOf:self.selection.location
-        [self selectRangePathWithLocation:newSelectionLocation
+                                                            selectWords:NO];
-                                   length:0];
+        self.selection = MPMakeRangePath(newSelectionLocation, 0);
     }
 }
 
@@ -232,48 +290,27 @@
 {
     if (self.selection.length > 0) {
         self.selection = MPMakeRangePath(self.selection.location, 0);
-        [self selectRangePathWithLocation:self.selection.location length:0];
     } else {
-        NSUInteger selectionIndex = self.selection.location.lastIndex;
+        NSIndexPath *newSelectionLocation = [self selectionToTheLeftOf:self.selection.location
-        if (selectionIndex > 0) {
+                                                           selectWords:NO];
-            --selectionIndex;
+        self.selection = MPMakeRangePath(newSelectionLocation, 0);
-        }
-        NSIndexPath *newSelectionLocation = [self.selection.location indexPathByReplacingLastIndexWithIndex:selectionIndex];
-        [self selectRangePathWithLocation:newSelectionLocation
-                                   length:0];
     }
 }
 
 - (void)moveWordRight:(id)sender
 {
-    NSIndexPath *location;
+    NSIndexPath *location = self.selection.maxRangePath;
-    if (self.selection.length > 0) {
+    NSIndexPath *newSelectionLocation = [self selectionToTheRightOf:location
-        location = self.selection.maxRangePath;
+                                                        selectWords:YES];
-    } else {
+    self.selection = MPMakeRangePath(newSelectionLocation, 0);
-        location = self.selection.location;
-    }
-    MPExpression *targetExpression = [self.expressionStorage elementAtIndexPath:[location indexPathByRemovingLastIndex]];
-    NSUInteger locationInTarget = NSMaxRange(self.selection.rangeAtLastIndex);
-    NSUInteger offset;
-    NSUInteger elementIndex = [targetExpression indexOfElementAtSymbolLocation:locationInTarget
-                                                                        offset:&offset];
-    NSUInteger newLocation = locationInTarget + [targetExpression elementAtIndex:elementIndex].length - offset;
-    [self selectRangePathWithLocation:[location indexPathByReplacingLastIndexWithIndex:newLocation]
-                               length:0];
 }
 
 - (void)moveWordLeft:(id)sender
 {
-    MPExpression *targetExpression = [self.expressionStorage elementAtIndexPath:[self.selection.location indexPathByRemovingLastIndex]];
+    NSIndexPath *location = self.selection.location;
-    NSUInteger offset;
+    NSIndexPath *newSelectionLocation = [self selectionToTheLeftOf:location
-    NSUInteger elementIndex = [targetExpression indexOfElementAtSymbolLocation:self.selection.location.lastIndex offset:&offset];
+                                                       selectWords:YES];
-    NSUInteger newLocation = self.selection.location.lastIndex;
+    self.selection = MPMakeRangePath(newSelectionLocation, 0);
-    if (offset > 0) {
-        newLocation -= newLocation - offset > 0 ? offset : newLocation;
-    } else if (newLocation > 0) {
-        newLocation -= [targetExpression elementAtIndex:elementIndex-1].length;
-    }
-    self.selection = MPMakeRangePath([self.selection.location indexPathByReplacingLastIndexWithIndex:newLocation], 0);
 }
 
 - (void)moveToBeginningOfLine:(id)sender
@@ -292,17 +329,16 @@
     if (self.selection.length == 0) {
         self.selectionModifyingStart = YES;
     }
-    NSUInteger start = self.selection.location.lastIndex;
+    NSIndexPath *location = self.selection.location;
-    NSUInteger length = self.selection.length;
+    NSIndexPath *maxLocation = self.selection.maxRangePath;
     if (self.selectionModifyingStart) {
-        if (start > 0) {
+        location = [self selectionToTheLeftOf:location
-            --start;
+                                  selectWords:NO];
-            ++length;
-        }
     } else {
-        --length;
+        maxLocation = [self selectionToTheLeftOf:maxLocation
+                                     selectWords:NO];
     }
-    self.selection = MPMakeRangePath([self.selection.location indexPathByReplacingLastIndexWithIndex:start], length);
+    self.selection = MPMakeRangePath(location, maxLocation.lastIndex-location.lastIndex);
 }
 
 - (void)moveRightAndModifySelection:(id)sender
@@ -310,26 +346,57 @@
     if (self.selection.length == 0) {
         self.selectionModifyingStart = NO;
     }
-    NSUInteger start = self.selection.location.lastIndex;
+    NSIndexPath *location = self.selection.location;
-    NSUInteger length = self.selection.length;
+    NSIndexPath *maxLocation = self.selection.maxRangePath;
+    
     if (self.selectionModifyingStart) {
-        ++start;
+        location = [self selectionToTheRightOf:location
-        --length;
+                                   selectWords:NO];
     } else {
-        ++length;
+        maxLocation = [self selectionToTheRightOf:maxLocation
+                                      selectWords:NO];
     }
-    [self selectRangePathWithLocation:[self.selection.location indexPathByReplacingLastIndexWithIndex:start]
+    self.selection = MPMakeRangePath(location, maxLocation.lastIndex-location.lastIndex);
-                               length:length];
 }
 
 - (void)moveWordRightAndModifySelection:(id)sender
 {
-#warning Unimplemented Method
+    if (self.selection.length == 0) {
+        self.selectionModifyingStart = NO;
+    }
+    NSIndexPath *location = self.selection.location;
+    NSIndexPath *maxLocation = self.selection.maxRangePath;
+    if (self.selectionModifyingStart) {
+        location = [self selectionToTheRightOf:location
+                                   selectWords:YES];
+        if (location.lastIndex > maxLocation.lastIndex) {
+            location = [location indexPathByReplacingLastIndexWithIndex:maxLocation.lastIndex];
+        }
+    } else {
+        maxLocation = [self selectionToTheRightOf:maxLocation
+                                      selectWords:YES];
+    }
+    self.selection = MPMakeRangePath(location, maxLocation.lastIndex-location.lastIndex);
 }
 
 - (void)moveWordLeftAndModifySelection:(id)sender
 {
-#warning Unimplemented Method
+    if (self.selection.length == 0) {
+        self.selectionModifyingStart = YES;
+    }
+    NSIndexPath *location = self.selection.location;
+    NSIndexPath *maxLocation = self.selection.maxRangePath;
+    if (self.selectionModifyingStart) {
+        location = [self selectionToTheLeftOf:location
+                                  selectWords:YES];
+    } else {
+        maxLocation = [self selectionToTheLeftOf:maxLocation
+                                     selectWords:YES];
+        if (maxLocation.lastIndex < location.lastIndex) {
+            maxLocation = [maxLocation indexPathByReplacingLastIndexWithIndex:location.lastIndex];
+        }
+    }
+    self.selection = MPMakeRangePath(location, maxLocation.lastIndex-location.lastIndex);
 }
 
 - (void)selectAll:(id)sender
@@ -359,9 +426,23 @@
     pointInView.x -= expressionOrigin.x;
     pointInView.y -= expressionOrigin.y;
     NSIndexPath *selectionPath = [self.expressionStorage.rootLayout indexPathForMousePoint:pointInView];
+    self.mouseAnchor = selectionPath;
     self.selection = MPMakeRangePath(selectionPath, 0);
 }
 
+- (void)mouseDragged:(NSEvent *)theEvent
+{
+    NSPoint pointInView = [self convertPoint:theEvent.locationInWindow
+                                    fromView:nil];
+    NSPoint expressionOrigin = self.expressionOrigin;
+    pointInView.x -= expressionOrigin.x;
+    pointInView.y -= expressionOrigin.y;
+    NSIndexPath *mouseSelectionPath = [self.expressionStorage.rootLayout indexPathForMousePoint:pointInView];
+    
+    self.selection = [self rangePathEnclosingAnchor:self.mouseAnchor
+                                       newSelection:mouseSelectionPath];
+}
+
 #pragma mark Drawing Methods
 - (void)drawRect:(NSRect)dirtyRect
 {