Fundamental Redesign of the View and Controller

MathPad/MPExpressionLayout.m

@@ -9,45 +9,38 @@
 #import "MPExpressionLayout.h"
 #import "MPFunctionLayout.h"
 
-@interface MPExpressionLayout (MPPathGeneration)
-
-- (NSBezierPath *)bezierPathForChildAtIndex:(NSUInteger)index;
-- (NSBezierPath *)generateBezierPathForString:(NSString *)aString;
+@interface MPExpressionLayout (MPLineGeneration)
 
+- (CTLineRef)lineForElementAtIndex:(NSUInteger)index;
+- (CTLineRef)createLineForString:(NSString *)aString;
 
 @end
 
-@implementation MPExpressionLayout (MPPathGeneration)
+@implementation MPExpressionLayout (MPLineGeneration)
 
-- (NSBezierPath *)bezierPathForChildAtIndex:(NSUInteger)index
+- (CTLineRef)lineForElementAtIndex:(NSUInteger)index
 {
-    id symbol = [self.expression elementAtIndex:index];
-    if ([symbol isString]) {
-        return [self cachableObjectForIndex:index
-                                  generator:^id{
-            return [self generateBezierPathForString:symbol];
-        }];
-    } else {
-        MPLayout *layout = [self childLayoutAtIndex:index];
-        return layout.bezierPath;
+    id element = [self.expression elementAtIndex:index];
+    if (![element isString]) {
+        return NULL;
     }
+    NSString *string = element;
+    id lineObject = [self cachableObjectForIndex:index generator:^id{
+        CTLineRef line = [self createLineForString:string];
+        return CFBridgingRelease(line);
+    }];
+    return (__bridge CTLineRef)lineObject;
 }
 
-- (NSBezierPath *)generateBezierPathForString:(NSString *)aString
+- (CTLineRef)createLineForString:(NSString *)aString
 {
+    
     NSAttributedString *text = [[NSAttributedString alloc] initWithString:aString
                                                                attributes:@{NSFontAttributeName: [NSFont fontWithName:@"Lucida Grande" size:18.0]}];
-    self.textStorage.attributedString = text;
-    NSRange glyphRange = [self.layoutManager glyphRangeForTextContainer:self.textContainer];
-    NSGlyph glyphs[glyphRange.length+1];
-    NSUInteger actualGlyphCount = [self.layoutManager getGlyphs:glyphs
-                                                          range:glyphRange];
-    NSBezierPath *path = [NSBezierPath bezierPath];
-    [path moveToPoint:NSZeroPoint];
-    [path appendBezierPathWithGlyphs:glyphs
-                               count:actualGlyphCount
-                              inFont:[NSFont fontWithName:@"Lucida Grande" size:18.0]];
-    return path;
+    CFAttributedStringRef attributedString = CFBridgingRetain(text);
+    CTLineRef line = CTLineCreateWithAttributedString(attributedString);
+    CFRelease(attributedString); // TODO: Is this release appropriate?
+    return line;
 }
 
 @end
@@ -60,6 +53,18 @@
     self = [super init];
     if (self) {
         _expressionStorage = expressionStorage;
+        _expression = expressionStorage;
+    }
+    return self;
+}
+
+- (instancetype)initWithPath:(NSIndexPath *)path
+                      parent:(MPLayout *)parent
+{
+    self = [super initWithPath:path
+                        parent:parent];
+    if (self) {
+        _expression = [parent.expressionStorage elementAtIndexPath:path];
     }
     return self;
 }
@@ -74,52 +79,92 @@
     return self.parent.expressionStorage;
 }
 
-- (MPExpression *)expression
-{
-    return [self.expressionStorage elementAtIndexPath:self.path];
-}
+//- (MPExpression *)expression
+//{
+//    return [self.expressionStorage elementAtIndexPath:self.path];
+//}
 
 #pragma mark Cache Methods
 - (MPLayout *)childLayoutAtIndex:(NSUInteger)index
 {
     id cachedObject = [self cachableObjectForIndex:index generator:^id{
-        NSIndexPath *indexPath = [self.path indexPathByAddingIndex:index];
+        NSIndexPath *indexPath = [self.expression.indexPath indexPathByAddingIndex:index];
         MPFunctionLayout *layout = [MPFunctionLayout functionLayoutForFunctionAtIndexPath:indexPath
                                                                                    parent:self];
         return layout;
     }];
-    if ([cachedObject isKindOfClass:[NSBezierPath class]]) {
-        return nil;
+    if ([cachedObject isKindOfClass:[MPLayout class]]) {
+        return cachedObject;
     }
-    return cachedObject;
+    return nil;
 }
 
-- (NSSize)sizeForChildAtIndex:(NSUInteger)index
+- (NSSize)sizeForElementAtIndex:(NSUInteger)index
 {
     id symbol = [self.expression elementAtIndex:index];
     if ([symbol isString]) {
-        return [self bezierPathForChildAtIndex:index].bounds.size;
+        CTLineRef line = [self lineForElementAtIndex:index];
+        CFRetain(line);
+        CGRect bounds = CTLineGetBoundsWithOptions(line, /*kCTLineBoundsUseOpticalBounds*/ 0);
+        CFRelease(line);
+        return bounds.size;
     } else {
         return [self childLayoutAtIndex:index].size;
     }
 }
 
 #pragma mark Drawing Methods
-- (NSBezierPath *)generateBezierPath
+- (NSSize)generateSize
 {
-    NSBezierPath *fullPath = [NSBezierPath bezierPath];
-    [fullPath moveToPoint:NSZeroPoint];
-    NSUInteger x = 0;
-    for (NSInteger index = 0; index < self.expression.numberOfElements; ++index) {
-        NSAffineTransform *transform = [NSAffineTransform transform];
-        // TODO: Translate by the right amount
-        [transform translateXBy:x yBy:0];
-        NSBezierPath *path = [self bezierPathForChildAtIndex:index].copy;
-        [path transformUsingAffineTransform:transform];
-        [fullPath appendBezierPath:path];
-        x += path.bounds.size.width;
+    CGFloat width = 0, height = 0;
+    for (NSUInteger index = 0; index < self.expression.numberOfElements; index++) {
+        NSSize elementSize = [self sizeForElementAtIndex:index];
+        width += elementSize.width;
+        height = MAX(height, elementSize.height);
     }
-    return fullPath;
+    return NSMakeSize(width, height);
+}
+
+- (void)drawAtPoint:(NSPoint)point
+{
+    // Get the current context
+    CGContextRef context =
+        (CGContextRef)[[NSGraphicsContext currentContext] graphicsPort];
+    CGContextSaveGState(context);
+    
+    // Set the text matrix
+    CGContextSetTextMatrix(context, CGAffineTransformIdentity);
+    
+    // Track the x position
+    CGFloat x = point.x;
+    
+    for (NSUInteger index = 0; index < self.expression.numberOfElements; index++) {
+        // The current element
+        id element = [self.expression elementAtIndex:index];
+        NSSize elementSize = [self sizeForElementAtIndex:index];
+        CGFloat dy = (self.size.height - elementSize.height) / 2;
+        CGFloat y = point.y + dy;
+        
+        if ([element isString]) {
+            // Get the line to draw
+            CTLineRef line = [self lineForElementAtIndex:index];
+            CFRetain(line);
+            
+            // Move to the appropriate position
+            CGContextSetTextPosition(context, x, y);
+                        
+            // Perform the drawing
+            CTLineDraw(line, context);
+
+            CFRelease(line);
+        } else {
+            // Let the child layout draw itself
+            MPLayout *layout = [self childLayoutAtIndex:index];
+            [layout drawAtPoint:NSMakePoint(x, y)];
+        }
+        x += elementSize.width;
+    }
+    CGContextRestoreGState(context);
 }
 
 @end