Corrected errors when selecting expressions

MathPad/MPExpressionView.m

@@ -9,6 +9,7 @@
 #import "MPExpressionView.h"
 #import "MPExpressionStorage.h"
 #import "MPExpressionLayout.h"
+#import "MPFunctionLayout.h"
 
 #import "MPRangePath.h"
 
@@ -48,13 +49,15 @@
 
 - (NSRect)selectionRect;
 
-- (NSIndexPath *)selectionToTheRightOf:(NSIndexPath *)selection
+- (NSIndexPath *)selectionToTheRightOf:(NSIndexPath *)selectionPath
-                           selectWords:(BOOL)flag;
+                  byExtendingSelection:(BOOL)extendingSelection
-- (NSIndexPath *)selectionToTheLeftOf:(NSIndexPath *)selection
+                           selectWords:(BOOL)selectWords;
-                          selectWords:(BOOL)flag;
+- (NSIndexPath *)selectionToTheLeftOf:(NSIndexPath *)selectionPath
+                 byExtendingSelection:(BOOL)extendingSelection
+                          selectWords:(BOOL)selectWords;
 
-- (MPRangePath *)rangePathEnclosingAnchor:(NSIndexPath *)anchor
+- (MPRangePath *)rangePathEnclosingAnchorPath:(NSIndexPath *)anchor
-                             newSelection:(NSIndexPath *)newSelection;
+                             newSelectionPath:(NSIndexPath *)newSelection;
 @end
 
 
@@ -101,43 +104,120 @@
     return selectionRect;
 }
 
-- (NSIndexPath *)selectionToTheRightOf:(NSIndexPath *)selection
+- (NSIndexPath *)selectionToTheRightOf:(NSIndexPath *)selectionPath
-                           selectWords:(BOOL)flag
+                  byExtendingSelection:(BOOL)extendingSelection
+                           selectWords:(BOOL)selectWords
 {
-    MPExpression *targetExpression = [self.expressionStorage elementAtIndexPath:[selection indexPathByRemovingLastIndex]];
+    NSIndexPath *targetExpressionPath = [selectionPath indexPathByRemovingLastIndex];
-    NSUInteger locationInTarget = selection.lastIndex;
+    MPExpression *targetExpression = [self.expressionStorage elementAtIndexPath:targetExpressionPath];
+    NSUInteger locationInTarget = selectionPath.lastIndex;
     NSUInteger locationInElement;
     NSUInteger targetElementIndex = [targetExpression indexOfElementAtSymbolLocation:locationInTarget
                                                                               offset:&locationInElement];
+    
     id<MPExpressionElement> targetElement;
+    // There is only a target element if the selection is not the last location in an expression
     if (targetElementIndex < targetExpression.numberOfElements) {
         targetElement = [targetExpression elementAtIndex:targetElementIndex];
     }
-    if (locationInElement == 0 && !flag) {
+    
-        NSLog(@"Move to next");
+    if (!selectWords && !extendingSelection && (locationInElement == 0 || locationInTarget == targetExpression.length)) {
-        // Move to next element
+        // First or last index in an element or expression
+        
+        // Last element in the expression
+        if (locationInTarget == targetExpression.length) {
+            // The selection is inside a function and should proceed
+            if (selectionPath.length > 1) {
+                NSIndexPath *functionPath = [[selectionPath indexPathByRemovingLastIndex] indexPathByRemovingLastIndex];
+                MPFunctionLayout *functionLayout = (MPFunctionLayout *)[self.expressionStorage.rootLayout childLayoutAtIndexPath:functionPath];
+                NSUInteger currentChildIndex = [selectionPath indexPathByRemovingLastIndex].lastIndex;
+                NSUInteger newChildIndex = [functionLayout indexOfChildAfterChildAtIndex:currentChildIndex];
+                
+                // The function is to be exited
+                if (newChildIndex == NSNotFound) {
+                    targetExpression = [self.expressionStorage elementAtIndexPath:[functionPath indexPathByRemovingLastIndex]];
+                    NSUInteger functionLocationInExpression = [targetExpression locationOfElementAtIndex:functionPath.lastIndex];
+                    return [functionPath indexPathByReplacingLastIndexWithIndex:functionLocationInExpression+1];
+                } else {
+                    return [[targetExpressionPath indexPathByReplacingLastIndexWithIndex:newChildIndex] indexPathByAddingIndex:0];
+                }
+            } // else the selection does not change
+            
+        // First Element
+        } else {
+            if ([targetElement isString]) {
+                locationInTarget++;
+            } else {
+                NSIndexPath *targetFunctionPath = [selectionPath indexPathByReplacingLastIndexWithIndex:targetElementIndex];
+                MPFunctionLayout *functionLayout = (MPFunctionLayout *)[self.expressionStorage.rootLayout childLayoutAtIndexPath:targetFunctionPath];
+                NSUInteger leadingChildIndex = [functionLayout indexOfLeadingChild];
+                return [[targetFunctionPath indexPathByAddingIndex:leadingChildIndex] indexPathByAddingIndex:0];
+            }
+        }
     } else if (locationInTarget < targetExpression.length) {
-        if (flag) {
+        if (selectWords) {
             locationInTarget = [targetExpression locationOfElementAtIndex:targetElementIndex+1];
         } else {
             locationInTarget++;
         }
     }
-    return [selection indexPathByReplacingLastIndexWithIndex:locationInTarget];
+    return [selectionPath indexPathByReplacingLastIndexWithIndex:locationInTarget];
 }
 
-- (NSIndexPath *)selectionToTheLeftOf:(NSIndexPath *)selection
+- (NSIndexPath *)selectionToTheLeftOf:(NSIndexPath *)selectionPath
-                          selectWords:(BOOL)flag
+                 byExtendingSelection:(BOOL)extendingSelection
+                          selectWords:(BOOL)selectWords
 {
-    MPExpression *targetExpression = [self.expressionStorage elementAtIndexPath:[selection indexPathByRemovingLastIndex]];
+    NSIndexPath *targetExpressionPath = [selectionPath indexPathByRemovingLastIndex];
-    NSUInteger locationInTarget = selection.lastIndex;
+    MPExpression *targetExpression = [self.expressionStorage elementAtIndexPath:targetExpressionPath];
+    NSUInteger locationInTarget = selectionPath.lastIndex;
     NSUInteger locationInElement;
     NSUInteger targetElementIndex = [targetExpression indexOfElementAtSymbolLocation:locationInTarget
                                                                               offset:&locationInElement];
-    if (locationInElement == 0 && !flag) {
+    
-        // Move to previous element
+    NSUInteger previousElementIndex = targetElementIndex - (locationInElement == 0 ? 1 : 0);
+    id<MPExpressionElement> previousElement;
+    if (locationInTarget > 0) {
+        previousElement = [targetExpression elementAtIndex:previousElementIndex];
+    }
+    
+    if (!selectWords && !extendingSelection && locationInElement == 0) {
+        // First element in expression
+        if (locationInTarget == 0) {
+            if (selectionPath.length > 1) {
+                NSIndexPath *functionPath = [[selectionPath indexPathByRemovingLastIndex] indexPathByRemovingLastIndex];
+                MPFunctionLayout *functionLayout = (MPFunctionLayout *)[self.expressionStorage.rootLayout childLayoutAtIndexPath:functionPath];
+                NSUInteger currentChildIndex = [selectionPath indexPathByRemovingLastIndex].lastIndex;
+                NSUInteger newChildIndex = [functionLayout indexOfChildBeforeChildAtIndex:currentChildIndex];
+                
+                // The function is to be exited
+                if (newChildIndex == NSNotFound) {
+                    targetExpression = [self.expressionStorage elementAtIndexPath:[functionPath indexPathByRemovingLastIndex]];
+                    NSUInteger functionLocationInExpression = [targetExpression locationOfElementAtIndex:functionPath.lastIndex];
+                    return [functionPath indexPathByReplacingLastIndexWithIndex:functionLocationInExpression];
+                } else {
+                    targetExpressionPath = [targetExpressionPath indexPathByReplacingLastIndexWithIndex:newChildIndex];
+                    targetExpression = [self.expressionStorage elementAtIndexPath:targetExpressionPath];
+                    return [targetExpressionPath indexPathByAddingIndex:targetExpression.length];
+                }
+            } // else the selection does not change
+            
+        // Just
+        } else {
+            if ([previousElement isString]) {
+                locationInTarget--;
+            } else {
+                NSIndexPath *targetFunctionPath = [selectionPath indexPathByReplacingLastIndexWithIndex:previousElementIndex];
+                MPFunctionLayout *functionLayout = (MPFunctionLayout *)[self.expressionStorage.rootLayout childLayoutAtIndexPath:targetFunctionPath];
+                NSUInteger trailingChildIndex = [functionLayout indexOfTrailingChild];
+                
+                targetExpressionPath = [targetFunctionPath indexPathByAddingIndex:trailingChildIndex];
+                targetExpression = [self.expressionStorage elementAtIndexPath:targetExpressionPath];
+                return [targetExpressionPath indexPathByAddingIndex:targetExpression.length];
+            }
+        }
     } else if (locationInTarget > 0) {
-        if (flag) {
+        if (selectWords) {
             if (locationInElement == 0) {
                 targetElementIndex--;
             }
@@ -146,13 +226,53 @@
             locationInTarget--;
         }
     }
-    return [selection indexPathByReplacingLastIndexWithIndex:locationInTarget];
+    return [selectionPath indexPathByReplacingLastIndexWithIndex:locationInTarget];
 }
 
-- (MPRangePath *)rangePathEnclosingAnchor:(NSIndexPath *)anchor
+- (MPRangePath *)rangePathEnclosingAnchorPath:(NSIndexPath *)anchorPath
-                             newSelection:(NSIndexPath *)newSelection
+                             newSelectionPath:(NSIndexPath *)newSelectionPath
 {
+    if ([anchorPath isEqual:newSelectionPath]) {
+        return MPMakeRangePath(anchorPath, 0);
+    }
     
+    NSIndexPath *commonPath = [anchorPath commonIndexPathWith:newSelectionPath];
+    if (commonPath.length == anchorPath.length-1 && commonPath.length == newSelectionPath.length-1) {
+        // The two paths point to different locations in the same expression
+        NSUInteger anchorIndex = [anchorPath indexAtPosition:commonPath.length];
+        NSUInteger newIndex = [newSelectionPath indexAtPosition:commonPath.length];
+        NSUInteger minIndex = MIN(anchorIndex, newIndex);
+        NSUInteger length = MAX(anchorIndex, newIndex) - minIndex;
+        return MPMakeRangePath([commonPath indexPathByAddingIndex:minIndex], length);
+    } else {
+        if ((commonPath.length & 1) == 1) {
+            commonPath = [commonPath indexPathByRemovingLastIndex];
+        }
+        MPExpression *closestCommonAncestor = [self.expressionStorage elementAtIndexPath:commonPath];
+        NSUInteger anchorIndex = [anchorPath indexAtPosition:commonPath.length];
+        NSUInteger newIndex = [newSelectionPath indexAtPosition:commonPath.length];
+        
+        if (commonPath.length < anchorPath.length-1) {
+            anchorIndex = [closestCommonAncestor locationOfElementAtIndex:anchorIndex];
+        }
+        if (commonPath.length < newSelectionPath.length-1) {
+            newIndex = [closestCommonAncestor locationOfElementAtIndex:newIndex];
+        }
+        
+        NSUInteger minIndex = MIN(anchorIndex, newIndex);
+        if (commonPath.length < anchorPath.length-1 && anchorIndex != minIndex) {
+            anchorIndex++;
+        } else if (commonPath.length < newSelectionPath.length-1 && newIndex != minIndex) {
+            newIndex++;
+        }
+        
+        NSUInteger length = MAX(anchorIndex, newIndex) - minIndex;
+        if (anchorIndex == newIndex) {
+            length++;
+        }
+        MPRangePath *newSelection = MPMakeRangePath([commonPath indexPathByAddingIndex:minIndex], length);
+        return newSelection;
+    }
 }
 
 @end
@@ -290,6 +410,7 @@
         self.selection = MPMakeRangePath(self.selection.maxRangePath, 0);
     } else {
         NSIndexPath *newSelectionLocation = [self selectionToTheRightOf:self.selection.location
+                                                   byExtendingSelection:NO
                                                             selectWords:NO];
         self.selection = MPMakeRangePath(newSelectionLocation, 0);
     }
@@ -301,6 +422,7 @@
         self.selection = MPMakeRangePath(self.selection.location, 0);
     } else {
         NSIndexPath *newSelectionLocation = [self selectionToTheLeftOf:self.selection.location
+                                                  byExtendingSelection:NO
                                                            selectWords:NO];
         self.selection = MPMakeRangePath(newSelectionLocation, 0);
     }
@@ -310,6 +432,7 @@
 {
     NSIndexPath *location = self.selection.maxRangePath;
     NSIndexPath *newSelectionLocation = [self selectionToTheRightOf:location
+                                               byExtendingSelection:NO
                                                         selectWords:YES];
     self.selection = MPMakeRangePath(newSelectionLocation, 0);
 }
@@ -318,6 +441,7 @@
 {
     NSIndexPath *location = self.selection.location;
     NSIndexPath *newSelectionLocation = [self selectionToTheLeftOf:location
+                                              byExtendingSelection:NO
                                                        selectWords:YES];
     self.selection = MPMakeRangePath(newSelectionLocation, 0);
 }
@@ -342,12 +466,16 @@
     NSIndexPath *maxLocation = self.selection.maxRangePath;
     if (self.selectionModifyingStart) {
         location = [self selectionToTheLeftOf:location
+                         byExtendingSelection:YES
                                   selectWords:NO];
     } else {
         maxLocation = [self selectionToTheLeftOf:maxLocation
+                            byExtendingSelection:YES
                                      selectWords:NO];
     }
-    self.selection = MPMakeRangePath(location, maxLocation.lastIndex-location.lastIndex);
+    self.selection = [self rangePathEnclosingAnchorPath:maxLocation newSelectionPath:location];
+    NSLog(@"%@", self.selection);
+//    self.selection = MPMakeRangePath(location, maxLocation.lastIndex-location.lastIndex);
 }
 
 - (void)moveRightAndModifySelection:(id)sender
@@ -360,9 +488,11 @@
     
     if (self.selectionModifyingStart) {
         location = [self selectionToTheRightOf:location
+                        byExtendingSelection:YES
                                  selectWords:NO];
     } else {
         maxLocation = [self selectionToTheRightOf:maxLocation
+                             byExtendingSelection:YES
                                       selectWords:NO];
     }
     self.selection = MPMakeRangePath(location, maxLocation.lastIndex-location.lastIndex);
@@ -377,12 +507,14 @@
     NSIndexPath *maxLocation = self.selection.maxRangePath;
     if (self.selectionModifyingStart) {
         location = [self selectionToTheRightOf:location
+                          byExtendingSelection:YES
                                    selectWords:YES];
         if (location.lastIndex > maxLocation.lastIndex) {
             location = [location indexPathByReplacingLastIndexWithIndex:maxLocation.lastIndex];
         }
     } else {
         maxLocation = [self selectionToTheRightOf:maxLocation
+                             byExtendingSelection:YES
                                       selectWords:YES];
     }
     self.selection = MPMakeRangePath(location, maxLocation.lastIndex-location.lastIndex);
@@ -397,9 +529,11 @@
     NSIndexPath *maxLocation = self.selection.maxRangePath;
     if (self.selectionModifyingStart) {
         location = [self selectionToTheLeftOf:location
+                         byExtendingSelection:YES
                                   selectWords:YES];
     } else {
         maxLocation = [self selectionToTheLeftOf:maxLocation
+                            byExtendingSelection:YES
                                      selectWords:YES];
         if (maxLocation.lastIndex < location.lastIndex) {
             maxLocation = [maxLocation indexPathByReplacingLastIndexWithIndex:location.lastIndex];
@@ -448,8 +582,8 @@
     pointInView.y -= expressionOrigin.y;
     NSIndexPath *mouseSelectionPath = [self.expressionStorage.rootLayout indexPathForMousePoint:pointInView];
     
-    self.selection = [self rangePathEnclosingAnchor:self.mouseAnchor
+    self.selection = [self rangePathEnclosingAnchorPath:self.mouseAnchor
-                                       newSelection:mouseSelectionPath];
+                                       newSelectionPath:mouseSelectionPath];
 }
 
 #pragma mark Drawing Methods

MathPad/NSIndexPath+MPAdditions.h

@@ -10,6 +10,7 @@
 
 @interface NSIndexPath (MPAdditions)
 
+- (NSUInteger)firstIndex;
 - (NSUInteger)lastIndex;
 
 - (NSIndexPath *)indexPathByReplacingLastIndexWithIndex:(NSUInteger)index;
@@ -34,7 +35,8 @@
 - (NSIndexPath *)indexPathByIncrementingLastIndex;
 - (NSIndexPath *)indexPathByDecrementingLastIndex;
 
-- (NSIndexPath *)indexPathWithLength:(NSUInteger)length; // use length indexes from the receiver, exception if too much
+- (NSIndexPath *)indexPathByRemovingIndexesFrom:(NSUInteger)length; // use length indexes from the receiver, exception if too much
+- (NSIndexPath *)indexPathByRemovingIndexesTo:(NSUInteger)length; // number of indexes from the beginning to exclude
 
 - (NSIndexPath *)commonIndexPathWith:(NSIndexPath *)indexPath;
 

MathPad/NSIndexPath+MPAdditions.m

@@ -10,6 +10,11 @@
 
 @implementation NSIndexPath (MPAdditions)
 
+- (NSUInteger)firstIndex
+{
+    return [self indexAtPosition:0];
+}
+
 - (NSUInteger)lastIndex
 {
     return [self indexAtPosition:self.length-1];
@@ -58,7 +63,7 @@
     return [[self indexPathByRemovingLastIndex] indexPathByAddingIndex:lastIndex];
 }
 
-- (NSIndexPath *)indexPathWithLength:(NSUInteger)length
+- (NSIndexPath *)indexPathByRemovingIndexesFrom:(NSUInteger)length
 {
     NSIndexPath *indexPath = [[NSIndexPath alloc] init];
     for (NSUInteger position = 0; position < length; position++) {
@@ -67,6 +72,15 @@
     return indexPath;
 }
 
+- (NSIndexPath *)indexPathByRemovingIndexesTo:(NSUInteger)length
+{
+    NSIndexPath *indexPath = [[NSIndexPath alloc] init];
+    for (NSUInteger position = length; position < self.length; position++) {
+        indexPath = [indexPath indexPathByAddingIndex:[self indexAtPosition:position]];
+    }
+    return indexPath;
+}
+
 - (NSIndexPath *)commonIndexPathWith:(NSIndexPath *)indexPath
 {
     NSIndexPath *commonPath = [[NSIndexPath alloc] init];