Merge pull request #3238 from daboe01/baseline-fixes

New: implement baseline offsets and superscript/subscript support

AppKit/CPFont.j

@@ -464,6 +464,22 @@ following:
     return _CPRealFontSize(_size);
 }
 
+/*!
+    Returns the font size. Cocoa/AppKit compatibility alias for -size.
+*/
+- (float)pointSize
+{
+    return [self size];
+}
+
+/*!
+    Returns the font name. Cocoa/AppKit compatibility alias for -familyName.
+*/
+- (CPString)fontName
+{
+    return [self familyName];
+}
+
 /*!
     Returns the font as a CSS string
 */

AppKit/CPTextView/CPLayoutManager.j

@@ -31,8 +31,9 @@
 @import "CPFont.j"
 
 @global _MakeRangeFromAbs
-
 @global document
+@global CPBaselineOffsetAttributeName
+@global CPSuperscriptAttributeName
 
 @class CPTextContainer
 @class CPTextView
@@ -1225,7 +1226,7 @@ var _objectsInRange = function(aList, aRange)
                 if (![attributes objectForKey:_CPAttachmentInvisible])
                 {
                     var view = [attributes objectForKey:_CPAttachmentView];
-                    var run = {_range:CPMakeRangeCopy(effectiveRange), color:nil, font:nil, elem:nil, string:nil, view:view, paragraphStyle:paragraphStyle};
+                    var run = {_range:CPMakeRangeCopy(effectiveRange), color:nil, font:nil, elem:nil, string:nil, view:view, paragraphStyle:paragraphStyle, underline:underline, baselineOffset:0.0};
                     _runs.push(run);
                 }
             }
@@ -1235,6 +1236,34 @@ var _objectsInRange = function(aList, aRange)
                     bgcolor = [attributes objectForKey:CPBackgroundColorAttributeName],
                     font = [attributes objectForKey:CPFontAttributeName] || [textStorage font] || [CPFont systemFontOfSize:12.0];
 
+                var baselineOffset = [attributes objectForKey:CPBaselineOffsetAttributeName],
+                    superscript = [attributes objectForKey:CPSuperscriptAttributeName];
+
+                if (baselineOffset === nil || baselineOffset === undefined || typeof baselineOffset !== "number")
+                    baselineOffset = 0.0;
+
+                if (superscript === nil || superscript === undefined || typeof superscript !== "number")
+                    superscript = 0;
+
+                if (superscript !== 0)
+                {
+                    var size = [font size],
+                        scaledSize = size * 0.65,
+                        fontName = [font familyName],
+                        isBold = [font isBold],
+                        isItalic = [font isItalic];
+
+                    font = [CPFont _fontWithName:fontName size:scaledSize bold:isBold italic:isItalic];
+
+                    if (baselineOffset === 0.0)
+                    {
+                        if (superscript > 0)
+                            baselineOffset = size * 0.35;
+                        else
+                            baselineOffset = -size * 0.15;
+                    }
+                }
+
                 var currentLoc = effectiveRange.location,
                     strLen = string.length,
                     startIdx = 0;
@@ -1254,7 +1283,9 @@ var _objectsInRange = function(aList, aRange)
                                     elem: nil,
                                     string: subString,
                                     bgcolor: bgcolor,
-                                    paragraphStyle: paragraphStyle
+                                    paragraphStyle: paragraphStyle,
+                                    underline: underline,
+                                    baselineOffset: baselineOffset
                                 };
                             _runs.push(run);
                         }
@@ -1267,7 +1298,9 @@ var _objectsInRange = function(aList, aRange)
                                 elem: nil,
                                 string: nil,
                                 bgcolor: nil,
-                                paragraphStyle: paragraphStyle
+                                paragraphStyle: paragraphStyle,
+                                underline: underline,
+                                baselineOffset: 0.0
                             };
                         _runs.push(tabRun);
 
@@ -1286,7 +1319,9 @@ var _objectsInRange = function(aList, aRange)
                             elem: nil,
                             string: subString,
                             bgcolor: bgcolor,
-                            paragraphStyle: paragraphStyle
+                            paragraphStyle: paragraphStyle,
+                            underline: underline,
+                            baselineOffset: baselineOffset
                         };
                     _runs.push(run);
                 }
@@ -1458,7 +1493,10 @@ var _objectsInRange = function(aList, aRange)
         if (!_RectEqualToRectHorizontally(newLineFragment._fragmentRect, _fragmentRect))
             return NO;
 
-        if (newFragmentRuns[i].color !== oldFragmentRuns[i].color || newFragmentRuns[i].bgcolor !== oldFragmentRuns[i].bgcolor || newFragmentRuns[i].font !== oldFragmentRuns[i].font)
+        if (newFragmentRuns[i].color !== oldFragmentRuns[i].color || 
+            newFragmentRuns[i].bgcolor !== oldFragmentRuns[i].bgcolor || 
+            newFragmentRuns[i].font !== oldFragmentRuns[i].font ||
+            newFragmentRuns[i].baselineOffset !== oldFragmentRuns[i].baselineOffset)
             return NO;
 
         var oldStyle = oldFragmentRuns[i].paragraphStyle || [CPParagraphStyle defaultParagraphStyle],

AppKit/CPTextView/CPTextView.j

@@ -1005,6 +1005,25 @@ Sets the selection to a range of characters in response to user action.
         if (doOverwrite && _placeholderString == nil && isNewSelection)
             [self setTypingAttributes:[_textStorage attributesAtIndex:CPMaxRange(range) effectiveRange:nil]];
 
+        // Update the shared CPColorPanel with the active selection color
+        if ([self _isFirstResponder] && [_textStorage length] > 0)
+        {
+            var currentTextColor = [self textColor] || [CPColor blackColor];
+
+            if ([self isRichText])
+            {
+                var charIndex = _selectionRange.location;
+                if (charIndex >= [_textStorage length])
+                    charIndex = MAX(0, charIndex - 1);
+
+                var attributes = [_textStorage attributesAtIndex:charIndex effectiveRange:nil];
+                if ([attributes objectForKey:CPForegroundColorAttributeName])
+                    currentTextColor = [attributes objectForKey:CPForegroundColorAttributeName];
+            }
+
+            [[CPColorPanel sharedColorPanel] setColor:currentTextColor];
+        }
+
         [[CPNotificationCenter defaultCenter] postNotificationName:CPTextViewDidChangeSelectionNotification object:self];
     }
 
@@ -1799,6 +1818,13 @@ Sets the selection to a range of characters in response to user action.
     // SYNCHRONIZE ACTIVE PARAGRAPH MARKERS ON TYPING ATTRIBUTES CHANGE
     [self updateRuler];
 
+    // Synchronize CPColorPanel if text view is active
+    if ([self _isFirstResponder])
+    {
+        var currentTextColor = [_typingAttributes objectForKey:CPForegroundColorAttributeName] || [self textColor] || [CPColor blackColor];
+        [[CPColorPanel sharedColorPanel] setColor:currentTextColor];
+    }
+
     [[CPNotificationCenter defaultCenter] postNotificationName:CPTextViewDidChangeTypingAttributesNotification object:self];
 
     // We always clear the saved selection range from the last mouse down event here.

AppKit/CPTextView/CPTypesetter.j

@@ -30,6 +30,9 @@
 @import "CPTextStorage.j"
 @import "CPFont.j"
 
+@global CPBaselineOffsetAttributeName
+@global CPSuperscriptAttributeName
+
 // forward declare these classes for type matching
 @class CPLayoutManager
 @class CPTextContainer
@@ -353,9 +356,41 @@ var CPSystemTypesetterFactory,
             if (!currentFont)
                 currentFont = [_textStorage font] || [CPFont systemFontOfSize:12.0];
 
-            ascent = [currentFont ascender];
-            descent = [currentFont descender];
-            leading = (ascent - descent) * 0.2; // FAKE leading
+            // Safely retrieve and validate CPBaselineOffsetAttributeName
+            var baselineOffset = [_currentAttributes objectForKey:CPBaselineOffsetAttributeName];
+            if (baselineOffset === nil || baselineOffset === undefined || typeof baselineOffset !== "number")
+                baselineOffset = 0.0;
+
+            // Safely retrieve and validate CPSuperscriptAttributeName
+            var superscript = [_currentAttributes objectForKey:CPSuperscriptAttributeName];
+            if (superscript === nil || superscript === undefined || typeof superscript !== "number")
+                superscript = 0;
+
+            if (superscript !== 0)
+            {
+                var size = [currentFont size],
+                    scaledSize = size * 0.65,
+                    fontName = [currentFont familyName],
+                    isBold = [currentFont isBold],
+                    isItalic = [currentFont isItalic];
+
+                currentFont = [CPFont _fontWithName:fontName size:scaledSize bold:isBold italic:isItalic];
+
+                if (baselineOffset === 0.0)
+                {
+                    if (superscript > 0)
+                        baselineOffset = size * 0.35;
+                    else
+                        baselineOffset = -size * 0.15;
+                }
+            }
+
+            var fontAscent = [currentFont ascender] || 0.0,
+                fontDescent = [currentFont descender] || 0.0;
+
+            ascent = fontAscent + baselineOffset;
+            descent = fontDescent + baselineOffset;
+            leading = (fontAscent - fontDescent) * 0.2; // FAKE leading
 
             currentFontLineHeight = ascent - descent + leading;
 
@@ -368,11 +403,15 @@ var CPSystemTypesetterFactory,
 
         }
 
-        if (currentFontLineHeight > _lineHeight)
-            _lineHeight = currentFontLineHeight;
+        // Clean bounds logic to prevent NaN and layout calculation overhead
+        var currentAscent = (ascent === undefined || isNaN(ascent)) ? 0.0 : ascent,
+            currentLineHeight = (currentFontLineHeight === undefined || isNaN(currentFontLineHeight)) ? 12.0 : currentFontLineHeight;
 
-        if (ascent > _lineBase)
-            _lineBase = ascent;
+        if (currentLineHeight > _lineHeight)
+            _lineHeight = currentLineHeight;
+
+        if (currentAscent > _lineBase)
+            _lineBase = currentAscent;
 
         lineRange.length++;
         measuringRange.length++;
@@ -546,7 +585,7 @@ var CPSystemTypesetterFactory,
                 isNewline = NO;
                 _lineFragments = [];
                 _lineHeight    = 0;
-                _lineBase      = ascent;
+                _lineBase      = 0;
                 isStartOfPhysicalLine = YES;
             }
 

AppKit/CPTextView/_CPRTFParser.j

@@ -38,6 +38,8 @@
 @global CPParagraphStyleAttributeName
 @global CPAttachmentAttributeName
 @global CPUnderlineStyleAttributeName
+@global CPBaselineOffsetAttributeName
+@global CPSuperscriptAttributeName
 
 @global CPLeftTabStopType
 @global CPRightTabStopType
@@ -72,6 +74,8 @@ var cp1252Map = {
     BOOL                script;
     BOOL                _tabChanged;
     CPTabStopType       _nextTabType;
+    int                 superscript;
+    float               baselineOffset;
 }
 
 - (id)init
@@ -104,6 +108,8 @@ var cp1252Map = {
     mynew.ulColour = ulColour;
     mynew._tabChanged = _tabChanged;
     mynew._nextTabType = _nextTabType;
+    mynew.superscript = superscript;
+    mynew.baselineOffset = baselineOffset;
 
     return mynew;
 }
@@ -169,6 +175,8 @@ var cp1252Map = {
     underline = 0;
     strikethrough = 0;
     script = 0;
+    superscript = 0;
+    baselineOffset = 0.0;
 }
 
 - (void)addTab:(float)location type:(CPTextTabType)type
@@ -212,6 +220,12 @@ var cp1252Map = {
     if (underline)
         [ret setObject:[CPNumber numberWithInt:1] forKey:CPUnderlineStyleAttributeName];
 
+    if (superscript !== 0)
+        [ret setObject:[CPNumber numberWithInt:superscript] forKey:CPSuperscriptAttributeName];
+
+    if (baselineOffset !== 0.0)
+        [ret setObject:[CPNumber numberWithFloat:baselineOffset] forKey:CPBaselineOffsetAttributeName];
+
     return ret;
 }
 @end
@@ -226,6 +240,12 @@ var kRgsymRtf = {
         "b"                                  : [ "b",        1,        false,     kRTFParserType_prop,    "propBold"],
         "ul"                                 : [ "ul",       1,        false,     kRTFParserType_prop,    "propUnderline"],
         "i"                                  : [ "i",        1,        false,     kRTFParserType_prop,    "propItalic"],
+        "super"                              : [ "super",    1,        true,      kRTFParserType_prop,    "propSuper"],
+        "sub"                                : [ "sub",      1,        true,      kRTFParserType_prop,    "propSub"],
+        "nosupersub"                         : [ "nosupersub",1,       true,      kRTFParserType_prop,    "propNoSuperSub"],
+        "up"                                 : [ "up",       6,        false,     kRTFParserType_prop,    "propUp"],
+        "dn"                                 : [ "dn",       6,        false,     kRTFParserType_prop,    "propDn"],
+        "plain"                              : [ "plain",    0,        false,     kRTFParserType_prop,    "propPlain"],
         "pgnucltr"                           : [ "pgnucltr", "pgULtr", true,      kRTFParserType_prop,    "propPgnFormat"],
         "pgnlcltr"                           : [ "pgnlcltr", "pgLLtr", true,      kRTFParserType_prop,    "propPgnFormat"],
         "qc"                                 : [ "qc",       "justC",  true,      kRTFParserType_prop,    "propJust"],
@@ -621,6 +641,36 @@ var kRgsymRtf = {
             }
             break;
 
+        case "super":
+            [self _flushCurrentRun];
+            _currentRun.superscript = 1;
+            break;
+
+        case "sub":
+            [self _flushCurrentRun];
+            _currentRun.superscript = -1;
+            break;
+
+        case "nosupersub":
+            [self _flushCurrentRun];
+            _currentRun.superscript = 0;
+            break;
+
+        case "up":
+            [self _flushCurrentRun];
+            _currentRun.baselineOffset = parseFloat(param) / 2.0;
+            break;
+
+        case "dn":
+            [self _flushCurrentRun];
+            _currentRun.baselineOffset = -parseFloat(param) / 2.0;
+            break;
+
+        case "plain":
+            [self _flushCurrentRun];
+            [_currentRun resetFont];
+            break;
+
         case "qc":  // paragraph center
             [_currentRun.paragraph setAlignment:CPCenterTextAlignment];
             break;

AppKit/CPTextView/_CPRTFProducer.j

@@ -646,28 +646,29 @@ function _points2twips(a) { return (a) * 20.0; }
         else if ([currAttrib isEqualToString:CPUnderlineStyleAttributeName])
         {
             headerString += @"\\ul";
-            trailerString += @"\\ulnone";
+            trailerString += @"\\ulnone "; // trailing space important!
         }
         else if ([currAttrib isEqualToString:CPSuperscriptAttributeName])
         {
             var value = [attributes objectForKey:CPSuperscriptAttributeName],
-                svalue = [value intValue] * 6;
+                ivalue = [value intValue];
 
-            if (svalue > 0)
+            if (ivalue > 0)
             {
-                headerString += [CPString stringWithFormat:@"\\up%d", svalue];
-                trailerString += @"\\up0";
+                headerString += @"\\super";
+                trailerString += @"\\nosupersub "; // trailing space important!
             }
-            else if (svalue < 0)
+            else if (ivalue < 0)
             {
-                headerString += [CPString stringWithFormat:@"\\dn-%d", svalue];
-                trailerString += @"\\dn0";
+                headerString += @"\\sub";
+                trailerString += @"\\nosupersub "; // trailing space important!
             }
         }
         else if ([currAttrib isEqualToString:CPBaselineOffsetAttributeName])
         {
             var value = [attributes objectForKey:CPBaselineOffsetAttributeName],
-                svalue = [value floatValue] * 2;
+                fvalue = [value floatValue],
+                svalue = Math.round(fvalue * 2.0); // Convert standard points to RTF half-points
 
             if (svalue > 0)
             {
@@ -676,7 +677,8 @@ function _points2twips(a) { return (a) * 20.0; }
             }
             else if (svalue < 0)
             {
-                headerString += [CPString stringWithFormat:@"\\dn-%d", svalue];
+                // Correct negative formatting using safe positive boundary
+                headerString += [CPString stringWithFormat:@"\\dn%d", Math.abs(svalue)];
                 trailerString += @"\\dn0";
             }
         }

Tests/Manual/CPTextView/AppController.j

@@ -8,6 +8,7 @@
 @import <Foundation/Foundation.j>
 @import <AppKit/CPTextView.j>
 @import <AppKit/CPFontPanel.j>
+@import <AppKit/CPColorPanel.j>
 @import <AppKit/CPRulerView.j>
 @import <AppKit/CPSplitView.j>
 @import <AppKit/CPButton.j>
@@ -17,6 +18,9 @@
 @import <AppKit/CPTextStorage.j>
 @import <AppKit/_CPTableTextAttachment.j>
 
+@global CPBaselineOffsetAttributeName
+@global CPSuperscriptAttributeName
+
 @implementation AppController : CPObject
 {
     CPTextView      _textView;
@@ -52,6 +56,11 @@
    [[CPFontManager sharedFontManager] orderFrontFontPanel:self];
 }
 
+- (void)orderFrontColorPanel:(id)sender
+{
+    [[CPColorPanel sharedColorPanel] orderFront:self];
+}
+
 - (void)toggleRuler:(id)sender
 {
     [_scrollView setRulersVisible:![_scrollView rulersVisible]];
@@ -77,6 +86,82 @@
     [_textView alignJustified:self];
 }
 
+- (void)makeSuperscript:(id)sender
+{
+    var range = [_textView selectedRange];
+    if (range.length > 0)
+    {
+        var textStorage = [_textView textStorage];
+        [textStorage beginEditing];
+        [textStorage removeAttribute:CPBaselineOffsetAttributeName range:range];
+        [textStorage addAttribute:CPSuperscriptAttributeName value:1 range:range];
+        [textStorage endEditing];
+        [_textView setNeedsDisplay:YES];
+    }
+}
+
+- (void)makeSubscript:(id)sender
+{
+    var range = [_textView selectedRange];
+    if (range.length > 0)
+    {
+        var textStorage = [_textView textStorage];
+        [textStorage beginEditing];
+        [textStorage removeAttribute:CPBaselineOffsetAttributeName range:range];
+        [textStorage addAttribute:CPSuperscriptAttributeName value:-1 range:range];
+        [textStorage endEditing];
+        [_textView setNeedsDisplay:YES];
+    }
+}
+
+- (void)raiseBaseline:(id)sender
+{
+    var range = [_textView selectedRange];
+    if (range.length > 0)
+    {
+        var textStorage = [_textView textStorage];
+        [textStorage beginEditing];
+        
+        var currentOffset = [textStorage attribute:CPBaselineOffsetAttributeName atIndex:range.location effectiveRange:nil] || 0.0;
+        var newOffset = currentOffset + 2.0;
+        
+        [textStorage addAttribute:CPBaselineOffsetAttributeName value:newOffset range:range];
+        [textStorage endEditing];
+        [_textView setNeedsDisplay:YES];
+    }
+}
+
+- (void)lowerBaseline:(id)sender
+{
+    var range = [_textView selectedRange];
+    if (range.length > 0)
+    {
+        var textStorage = [_textView textStorage];
+        [textStorage beginEditing];
+        
+        var currentOffset = [textStorage attribute:CPBaselineOffsetAttributeName atIndex:range.location effectiveRange:nil] || 0.0;
+        var newOffset = currentOffset - 2.0;
+        
+        [textStorage addAttribute:CPBaselineOffsetAttributeName value:newOffset range:range];
+        [textStorage endEditing];
+        [_textView setNeedsDisplay:YES];
+    }
+}
+
+- (void)resetBaseline:(id)sender
+{
+    var range = [_textView selectedRange];
+    if (range.length > 0)
+    {
+        var textStorage = [_textView textStorage];
+        [textStorage beginEditing];
+        [textStorage removeAttribute:CPBaselineOffsetAttributeName range:range];
+        [textStorage removeAttribute:CPSuperscriptAttributeName range:range];
+        [textStorage endEditing];
+        [_textView setNeedsDisplay:YES];
+    }
+}
+
 - (void)insertAttachment:(id)sender
 {
     // Insert modern spinner image attachment
@@ -215,6 +300,48 @@
     [alignJustifyBtn setTarget:self];
     [alignJustifyBtn setAction:@selector(alignJustified:)];
     [toolbarView addSubview:alignJustifyBtn];
+    currentX += 80;
+
+    // Baseline & Script Testing Group
+    var labelBaseline = [[CPTextField alloc] initWithFrame:CGRectMake(currentX, 22, 85, 20)];
+    [labelBaseline setStringValue:@"Baseline:"];
+    [labelBaseline setFont:[CPFont systemFontOfSize:12]];
+    [toolbarView addSubview:labelBaseline];
+    currentX += 85;
+
+    var superBtn = [[CPButton alloc] initWithFrame:CGRectMake(currentX, 15, 45, 30)];
+    [superBtn setTitle:@"x²"];
+    [superBtn setTarget:self];
+    [superBtn setAction:@selector(makeSuperscript:)];
+    [toolbarView addSubview:superBtn];
+    currentX += 50;
+
+    var subBtn = [[CPButton alloc] initWithFrame:CGRectMake(currentX, 15, 45, 30)];
+    [subBtn setTitle:@"x₂"];
+    [subBtn setTarget:self];
+    [subBtn setAction:@selector(makeSubscript:)];
+    [toolbarView addSubview:subBtn];
+    currentX += 50;
+
+    var raiseBtn = [[CPButton alloc] initWithFrame:CGRectMake(currentX, 15, 50, 30)];
+    [raiseBtn setTitle:@"Base+"];
+    [raiseBtn setTarget:self];
+    [raiseBtn setAction:@selector(raiseBaseline:)];
+    [toolbarView addSubview:raiseBtn];
+    currentX += 55;
+
+    var lowerBtn = [[CPButton alloc] initWithFrame:CGRectMake(currentX, 15, 50, 30)];
+    [lowerBtn setTitle:@"Base-"];
+    [lowerBtn setTarget:self];
+    [lowerBtn setAction:@selector(lowerBaseline:)];
+    [toolbarView addSubview:lowerBtn];
+    currentX += 55;
+
+    var normalBtn = [[CPButton alloc] initWithFrame:CGRectMake(currentX, 15, 60, 30)];
+    [normalBtn setTitle:@"Normal"];
+    [normalBtn setTarget:self];
+    [normalBtn setAction:@selector(resetBaseline:)];
+    [toolbarView addSubview:normalBtn];
 
     // Default return key target test
     var returnButton = [[CPButton alloc] initWithFrame:CGRectMake(CGRectGetWidth([contentView bounds]) - 270, 15, 250, 30)];
@@ -299,12 +426,20 @@
     var formatMenu = [[CPMenu alloc] initWithTitle:@"Format Menu"];
     
     [formatMenu addItemWithTitle:@"Font panel" action:@selector(orderFrontFontPanel:) keyEquivalent:@"t"];
+    [formatMenu addItemWithTitle:@"Color panel" action:@selector(orderFrontColorPanel:) keyEquivalent:@"C"];
     [formatMenu addItem:[CPMenuItem separatorItem]];
     // Styles
     [formatMenu addItemWithTitle:@"Bold" action:@selector(bold:) keyEquivalent:@"b"];
     [formatMenu addItemWithTitle:@"Italic" action:@selector(italic:) keyEquivalent:@"i"];
     [formatMenu addItemWithTitle:@"Underline" action:@selector(underline:) keyEquivalent:@"u"];
     [formatMenu addItem:[CPMenuItem separatorItem]];
+    // Baseline & Scripts
+    [formatMenu addItemWithTitle:@"Superscript" action:@selector(makeSuperscript:) keyEquivalent:@"="];
+    [formatMenu addItemWithTitle:@"Subscript" action:@selector(makeSubscript:) keyEquivalent:@"-"];
+    [formatMenu addItemWithTitle:@"Raise Baseline" action:@selector(raiseBaseline:) keyEquivalent:@"+"];
+    [formatMenu addItemWithTitle:@"Lower Baseline" action:@selector(lowerBaseline:) keyEquivalent:@"_"];
+    [formatMenu addItemWithTitle:@"Reset Baseline" action:@selector(resetBaseline:) keyEquivalent:@"0"];
+    [formatMenu addItem:[CPMenuItem separatorItem]];
     // Alignment
     [formatMenu addItemWithTitle:@"Align Left" action:@selector(alignLeft:) keyEquivalent:@"{"];
     [formatMenu addItemWithTitle:@"Center" action:@selector(alignCenter:) keyEquivalent:@"|"];
@@ -327,6 +462,51 @@
                                                           attributes:[CPDictionary dictionaryWithObjects:[centeredParagraph, [CPFont boldFontWithName:@"Arial" size:18], elegantForeground, elegantBackground]
                                                                                                  forKeys:[CPParagraphStyleAttributeName, CPFontAttributeName, CPForegroundColorAttributeName, CPBackgroundColorAttributeName]]]];
 
+    // VISUAL TEST CASES: Baseline, Superscript, and Subscript Features
+    [_textView insertText:@"\n"];
+    var sectionHeaderColor = [CPColor colorWithRed:0.5 green:0.25 blue:0.1 alpha:1.0];
+    [_textView insertText:[[CPAttributedString alloc] initWithString:@"Baseline Shift & Superscript/Subscript Showcase\n"
+                                                          attributes:[CPDictionary dictionaryWithObjects:[[CPFont boldFontWithName:@"Arial" size:16], sectionHeaderColor]
+                                                                                                 forKeys:[CPFontAttributeName, CPForegroundColorAttributeName]]]];
+
+    var normalFont = [CPFont systemFontOfSize:14.0];
+    
+    // Test Case: E = mc² (Superscript)
+    var formulaEnergy = [[CPAttributedString alloc] initWithString:@" • Energy mass equivalence: E = mc" attributes:@{ CPFontAttributeName: normalFont }];
+    var scriptTwo = [[CPAttributedString alloc] initWithString:@"2" attributes:@{ CPFontAttributeName: normalFont, CPSuperscriptAttributeName: 1 }];
+    [_textView insertText:formulaEnergy];
+    [_textView insertText:scriptTwo];
+    [_textView insertText:@"\n"];
+
+    // Test Case: H₂O (Subscript)
+    var formulaWater = [[CPAttributedString alloc] initWithString:@" • Chemical formula: H" attributes:@{ CPFontAttributeName: normalFont }];
+    var scriptSubTwo = [[CPAttributedString alloc] initWithString:@"2" attributes:@{ CPFontAttributeName: normalFont, CPSuperscriptAttributeName: -1 }];
+    var formulaWaterEnd = [[CPAttributedString alloc] initWithString:@"O\n" attributes:@{ CPFontAttributeName: normalFont }];
+    [_textView insertText:formulaWater];
+    [_textView insertText:scriptSubTwo];
+    [_textView insertText:formulaWaterEnd];
+
+    // Test Case: Ordinals
+    var ordText = [[CPAttributedString alloc] initWithString:@" • Ordinals: 1" attributes:@{ CPFontAttributeName: normalFont }];
+    var st = [[CPAttributedString alloc] initWithString:@"st" attributes:@{ CPFontAttributeName: normalFont, CPSuperscriptAttributeName: 1 }];
+    var rdText = [[CPAttributedString alloc] initWithString:@", 3" attributes:@{ CPFontAttributeName: normalFont }];
+    var rd = [[CPAttributedString alloc] initWithString:@"rd" attributes:@{ CPFontAttributeName: normalFont, CPSuperscriptAttributeName: 1 }];
+    [_textView insertText:ordText];
+    [_textView insertText:st];
+    [_textView insertText:rdText];
+    [_textView insertText:rd];
+    [_textView insertText:@"\n"];
+
+    // Test Case: Custom Baseline Offsets
+    var offsetLead = [[CPAttributedString alloc] initWithString:@" • Custom Offsets: " attributes:@{ CPFontAttributeName: normalFont }];
+    var offsetUp = [[CPAttributedString alloc] initWithString:@"Raised " attributes:@{ CPFontAttributeName: normalFont, CPBaselineOffsetAttributeName: 4.0 }];
+    var offsetDown = [[CPAttributedString alloc] initWithString:@"Lowered " attributes:@{ CPFontAttributeName: normalFont, CPBaselineOffsetAttributeName: -4.0 }];
+    var offsetNormal = [[CPAttributedString alloc] initWithString:@"Standard\n" attributes:@{ CPFontAttributeName: normalFont }];
+    [_textView insertText:offsetLead];
+    [_textView insertText:offsetUp];
+    [_textView insertText:offsetDown];
+    [_textView insertText:offsetNormal];
+
     // Highlighted Heading - Pine & Sage Green tones
     [_textView insertText:@"\n"];
     var showcaseForeground = [CPColor colorWithRed:0.15 green:0.25 blue:0.15 alpha:1.0]; // Forest Green