libs-gui/Source/GSFontInfo.m

/*
   GSFontInfo

   Private class for handling font info

   Copyright (C) 2000, 2020 Free Software Foundation, Inc.

   Author: Adam Fedor <fedor@gnu.org>
   Date: Mar 2000

   Author: Fred Kiefer <fredkiefer@gmx.de>
   Date:   March 2020

   This file is part of the GNUstep.

   This library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2 of the License, or (at your option) any later version.

   This library is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.	 See the GNU
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with this library; see the file COPYING.LIB.
   If not, see <http://www.gnu.org/licenses/> or write to the
   Free Software Foundation, 51 Franklin Street, Fifth Floor,
   Boston, MA 02110-1301, USA.
*/

#include <math.h>

#import <Foundation/NSAffineTransform.h>
#import <Foundation/NSArray.h>
#import <Foundation/NSCharacterSet.h>
#import <Foundation/NSDictionary.h>
#import <Foundation/NSEnumerator.h>
#import <Foundation/NSException.h>
#import <Foundation/NSSet.h>
#import <Foundation/NSString.h>
#import <Foundation/NSValue.h>

#import "AppKit/NSFontDescriptor.h"

#import "GNUstepGUI/GSFontInfo.h"

static Class fontEnumeratorClass = Nil;
static Class fontInfoClass = Nil;

static GSFontEnumerator *sharedEnumerator = nil;

@implementation GSFontEnumerator

+ (void) setDefaultClass: (Class)defaultClass
{
  fontEnumeratorClass = defaultClass;
}

- (id) init
{
  [super init];
  [self enumerateFontsAndFamilies];

  return self;
}

- (void) dealloc
{
  RELEASE(allFontNames);
  RELEASE(allFontFamilies);
  [super dealloc];
}

+ (GSFontEnumerator*) sharedEnumerator
{
  NSAssert(fontEnumeratorClass,
    @"Called with fontEnumeratorClass unset."
    @" The shared NSApplication instance must be created before methods that"
    @" need the backend may be called.");
  if (!sharedEnumerator)
    sharedEnumerator = [[fontEnumeratorClass alloc] init];
  return sharedEnumerator;
}

- (void) enumerateFontsAndFamilies
{
  // This method has to set up the ivars allFontNames and allFontFamilies
  [self subclassResponsibility: _cmd];
}

- (NSArray*) availableFonts
{
  return allFontNames;
}

- (NSArray*) availableFontFamilies
{
  return [[allFontFamilies allKeys] sortedArrayUsingSelector:
    @selector(compare:)];
}

- (NSArray*) availableMembersOfFontFamily: (NSString*)family
{
  return [allFontFamilies objectForKey: family];
}

- (NSArray*) availableFontDescriptors
{
  if (allFontDescriptors == nil)
    {
      NSMutableArray *fontDescriptors;
      NSEnumerator *keyEnumerator;
      NSString *family;

      fontDescriptors = [[NSMutableArray alloc] init];
      keyEnumerator = [allFontFamilies keyEnumerator];
      while ((family = [keyEnumerator nextObject]) != nil)
        {
          NSArray *fontDefs = [allFontFamilies objectForKey: family];
          NSEnumerator *fdEnumerator;
          NSArray *fontDef;

          fdEnumerator = [fontDefs objectEnumerator];
          while ((fontDef = [fdEnumerator nextObject]) != nil)
            {
              NSFontDescriptor *fd;
              NSDictionary *attributes;
              NSNumber *weight = [fontDef objectAtIndex: 2];
              NSNumber *traits = [fontDef objectAtIndex: 3];
              NSDictionary *fontTraits;
              float fweight = ([weight intValue] - 6) / 6.0;

              fontTraits = [NSDictionary dictionaryWithObjectsAndKeys:
                                           traits, NSFontSymbolicTrait,
                                         [NSNumber numberWithFloat: fweight],
                                         NSFontWeightTrait,
                                         nil];
              attributes = [NSDictionary dictionaryWithObjectsAndKeys:
                                           family, NSFontFamilyAttribute,
                                         [fontDef objectAtIndex: 0], NSFontNameAttribute,
                                     [fontDef objectAtIndex: 1], NSFontFaceAttribute,
                                         fontTraits, NSFontTraitsAttribute,
                                         nil];
              fd = [[NSFontDescriptor alloc] initWithFontAttributes: attributes];

              [fontDescriptors addObject: fd];
              RELEASE(fd);
            }
        }

      allFontDescriptors = fontDescriptors;
    }

  return allFontDescriptors;
}

- (NSArray *) availableFontNamesMatchingFontDescriptor: (NSFontDescriptor *)descriptor
{
  NSString *fontName;
  NSArray *fds;
  NSMutableArray *found;
  NSEnumerator *fdEnumerator;
  NSFontDescriptor *fd;

  fontName = [descriptor objectForKey: NSFontNameAttribute];
  if (fontName != nil)
    {
      return [NSArray arrayWithObject: fontName];
    }

  found = [NSMutableArray array];
  // Normalize the font descriptor
  fds = [descriptor matchingFontDescriptorsWithMandatoryKeys: nil];
  fdEnumerator = [fds objectEnumerator];
  while ((fd = [fdEnumerator nextObject]) != nil)
    {
      fontName = [fd objectForKey: NSFontNameAttribute];
      if (fontName != nil)
        {
          [found addObject: fontName];
        }
    }

  return found;
}

- (BOOL) _fontDescriptor: (NSFontDescriptor *)fd matches: (NSDictionary *)attributes
{
  // Get all the keys from the attributes and see if they match
  NSArray *keys = [attributes allKeys];
  NSEnumerator *keyEnumerator;
  NSString *key;
  BOOL match = YES;

  keyEnumerator = [keys objectEnumerator];
  while ((key = [keyEnumerator nextObject]) != nil)
    {
      id valueA = [attributes objectForKey: key];

      if (valueA != nil)
        {
          id valueB = [fd objectForKey: key];

          if (valueB == nil)
            {
              match = NO;
              break;
            }

          // Special handling for NSFontTraitsAttribute
          if ([key isEqual: NSFontTraitsAttribute])
            {
              NSNumber *traitsA = [valueA objectForKey: NSFontSymbolicTrait];
              NSNumber *traitsB = [valueB objectForKey: NSFontSymbolicTrait];

              // FIXME: For now we only compare symbolic traits
              if ((traitsA != nil) &&
                  ((traitsB == nil) ||
                   ([traitsA unsignedIntValue] != [traitsB unsignedIntValue])))
                {
                  match = NO;
                  break;
                }
            }
          else if ([key isEqual: NSFontCharacterSetAttribute])
            {
              if (![valueB isSupersetOfSet: valueA])
                {
                  match = NO;
                  break;
                }
            }
          else
            {
              if (![valueA isEqual: valueB])
                {
                  match = NO;
                  break;
                }
            }
        }
    }

  return match;
}

- (NSArray *) matchingFontDescriptorsFor: (NSDictionary *)attributes
{
  NSMutableArray *found;
  NSEnumerator *fdEnumerator;
  NSFontDescriptor *fd;

  found = [NSMutableArray arrayWithCapacity: 3];
  // Get an enumerator for all available font descriptors
  fdEnumerator = [[self availableFontDescriptors] objectEnumerator];
  while ((fd = [fdEnumerator nextObject]) != nil)
    {
      if ([self _fontDescriptor: fd matches: attributes])
        {
          [found addObject: fd];
        }
    }

  return found;
}

// Font collection methods....

- (BOOL) _fontDescriptor: (NSFontDescriptor *)fd matchesAny: (NSArray *)a
{
  NSEnumerator *en = [a objectEnumerator];
  NSFontDescriptor *o;

  while ((o = [en nextObject]) != nil)
    {
      if ([self _fontDescriptor: fd matches: [o fontAttributes]])
        {
          return YES;
        }
    }

  return NO;
}

/*
 * This method implements the filtering of font descriptors to match the given restrictions.
 * This code should be implemented more effiently in the backend.
 * Currently we ignore the options as these may only be implemented in the backend.
 */
- (NSArray *) matchingDescriptorsForFamily: (NSString *)family
                                   options: (NSDictionary *)options
                                 inclusion: (NSArray *)queryDescriptors
                                 exculsion: (NSArray *)exclusionDescriptors
{
  NSMutableArray *r = [NSMutableArray arrayWithCapacity: 50];
  NSEnumerator *en = [[self availableFontDescriptors] objectEnumerator];
  NSFontDescriptor *fd;

  while ((fd = [en nextObject]) != nil)
    {
      // Check if the font descriptor matches the family value if one is given
      if ((family != nil) &&
          ![[fd objectForKey: NSFontFamilyAttribute] isEqualToString: family])
        {
          continue;
        }

      // Check if the font descriptor matches any of the query descriptors
      if (![self _fontDescriptor: fd matchesAny: queryDescriptors])
        {
          continue;
        }

      // Check if the font descriptor matches none of the exclusion descriptors
      if ([self _fontDescriptor: fd matchesAny: exclusionDescriptors])
        {
          continue;
        }

      // Add it to the result
      [r addObject: fd];
    }

  return r;
}

- (NSString *) defaultSystemFontName
{
  return @"Helvetica";
}

- (NSString *) defaultBoldSystemFontName
{
  return @"Helvetica-Bold";
}

- (NSString *) defaultFixedPitchFontName
{
  return @"Courier";
}

@end

@interface GSFontInfo (Backend)
-initWithFontName: (NSString *)fontName
	   matrix: (const CGFloat *)fmatrix
       screenFont: (BOOL)screenFont;
@end

@implementation GSFontInfo

+ (void) setDefaultClass: (Class)defaultClass
{
  fontInfoClass = defaultClass;
}

+ (GSFontInfo*) fontInfoForFontName: (NSString*)nfontName
                             matrix: (const CGFloat *)fmatrix
			 screenFont: (BOOL)screenFont;
{
  NSAssert(fontInfoClass,
    @"Called with fontInfoClass unset."
    @" The shared NSApplication instance must be created before methods that"
    @" need the backend may be called.");
  return AUTORELEASE([[fontInfoClass alloc] initWithFontName: nfontName
						      matrix: fmatrix
						  screenFont: screenFont]);
}

+ (int) weightForString: (NSString *)weightString
{
  static NSDictionary *dict = nil;
  NSNumber *num;

  if (dict == nil)
    {
      dict = [NSDictionary dictionaryWithObjectsAndKeys:
	[NSNumber numberWithInt: 1], @"ultralight",
	[NSNumber numberWithInt: 2], @"thin",
	[NSNumber numberWithInt: 3], @"light",
	[NSNumber numberWithInt: 3], @"extralight",
	[NSNumber numberWithInt: 4], @"book",
	[NSNumber numberWithInt: 5], @"regular",
	[NSNumber numberWithInt: 5], @"plain",
	[NSNumber numberWithInt: 5], @"display",
	[NSNumber numberWithInt: 5], @"roman",
	[NSNumber numberWithInt: 5], @"semilight",
	[NSNumber numberWithInt: 6], @"medium",
	[NSNumber numberWithInt: 7], @"demi",
	[NSNumber numberWithInt: 7], @"demibold",
	[NSNumber numberWithInt: 8], @"semi",
	[NSNumber numberWithInt: 8], @"semibold",
	[NSNumber numberWithInt: 9], @"bold",
	[NSNumber numberWithInt: 10], @"extra",
	[NSNumber numberWithInt: 10], @"extrabold",
	[NSNumber numberWithInt: 11], @"heavy",
	[NSNumber numberWithInt: 11], @"heavyface",
	[NSNumber numberWithInt: 12], @"ultrabold",
	[NSNumber numberWithInt: 12], @"black",
	[NSNumber numberWithInt: 13], @"ultra",
	[NSNumber numberWithInt: 13], @"ultrablack",
	[NSNumber numberWithInt: 13], @"fat",
	[NSNumber numberWithInt: 14], @"extrablack",
	[NSNumber numberWithInt: 14], @"obese",
	[NSNumber numberWithInt: 14], @"nord",
	nil];
      RETAIN(dict);
    }

  if ((weightString == nil) ||
      ((num = [dict objectForKey: weightString]) == nil))
    {
      return 5;
    }
  else
    {
      return [num intValue];
    }
}

+ (NSString *) stringForWeight: (int)aWeight
{
  static NSArray *arr = nil;

  if (arr == nil)
    {
      arr = [NSArray arrayWithObjects: @"", @"ultralight",
	@"thin", @"light", @"book", @"regular",
	@"medium", @"demibold", @"semibold",
	@"bold", @"extrabold", @"heavy",
	@"black", @"ultrablack", @"extrablack",
	nil];
      RETAIN(arr);
    }

  if ((aWeight < 1) || (aWeight > 14))
    return @"";
  else
    return [arr objectAtIndex: aWeight];
}

- init
{
  [super init];
  mostCompatibleStringEncoding = NSASCIIStringEncoding;

  return self;
}

- (void) dealloc
{
  RELEASE(coveredCharacterSet);
  RELEASE(fontDictionary);
  RELEASE(fontName);
  RELEASE(familyName);
  RELEASE(encodingScheme);
  TEST_RELEASE(fontDescriptor);
  [super dealloc];
}

- (id) copyWithZone: (NSZone *)zone
{
  GSFontInfo *copy;
  if (NSShouldRetainWithZone(self, zone))
    copy = RETAIN(self);
  else
    {
      copy = (GSFontInfo*) NSCopyObject (self, 0, zone);
      copy->fontDictionary = [fontDictionary copyWithZone: zone];
      copy->fontName = [fontName copyWithZone: zone];
      copy->familyName = [familyName copyWithZone: zone];
      copy->encodingScheme = [encodingScheme copyWithZone: zone];
      copy->fontDescriptor = [fontDescriptor copyWithZone: zone];
    }
  return copy;
}

/* We really want a mutable class for this, but this is quick and easy since
   it's not really a public class anyway */
- (id) mutableCopyWithZone: (NSZone *)zone
{
  GSFontInfo *copy;
  copy = (GSFontInfo*) NSCopyObject (self, 0, zone);
  copy->fontDictionary = [fontDictionary copyWithZone: zone];
  copy->fontName = [fontName copyWithZone: zone];
  copy->familyName = [familyName copyWithZone: zone];
  copy->encodingScheme = [encodingScheme copyWithZone: zone];
  copy->fontDescriptor = [fontDescriptor copyWithZone: zone];
  return copy;
}

- (void) set
{
  [self subclassResponsibility: _cmd];
}

- (NSDictionary*) afmDictionary
{
  if (fontDictionary == nil)
    {
      NSString *weightString;

      fontDictionary = [[NSMutableDictionary alloc] initWithCapacity: 25];

      [fontDictionary setObject: fontName forKey: NSAFMFontName];
      if (familyName != nil)
        {
	  [fontDictionary setObject: familyName
			  forKey: NSAFMFamilyName];
	}
      if (ascender != 0.0)
        {
	  [fontDictionary setObject: [NSNumber numberWithFloat: ascender]
			  forKey: NSAFMAscender];
	}
      if (descender != 0.0)
        {
	  [fontDictionary setObject: [NSNumber numberWithFloat: descender]
			  forKey: NSAFMDescender];
	}
      if (xHeight != 0.0)
        {
	  [fontDictionary setObject: [NSNumber numberWithFloat: xHeight]
			  forKey: NSAFMXHeight];
	}
      if (capHeight != 0.0)
        {
	  [fontDictionary setObject: [NSNumber numberWithFloat: capHeight]
			  forKey: NSAFMCapHeight];
	}
      if (italicAngle != 0.0)
        {
	  [fontDictionary setObject: [NSNumber numberWithFloat: italicAngle]
			  forKey: NSAFMItalicAngle];
	}
      if (underlinePosition != 0.0)
        {
	  [fontDictionary setObject: [NSNumber numberWithFloat: underlinePosition]
			  forKey: NSAFMUnderlinePosition];
	}
      if (underlineThickness != 0.0)
        {
	  [fontDictionary setObject: [NSNumber numberWithFloat: underlineThickness]
			  forKey: NSAFMUnderlineThickness];
	}

      weightString = [GSFontInfo stringForWeight: weight];
      if (weightString != nil)
        {
	  [fontDictionary setObject: weightString forKey: NSAFMWeight];
	}
      if (encodingScheme != nil)
        {
	  [fontDictionary setObject: encodingScheme
			  forKey: NSAFMEncodingScheme];
	}

    }
  return fontDictionary;
}

- (NSString *) afmFileContents
{
  return nil;
}

- (NSCharacterSet*) coveredCharacterSet
{
  return coveredCharacterSet;
}

- (NSString*) encodingScheme
{
  return encodingScheme;
}

- (NSRect) boundingRectForFont
{
  return fontBBox;
}

- (NSString*) displayName
{
  return familyName;
}

- (NSString*) familyName
{
  return familyName;
}

- (const CGFloat*) matrix
{
  return matrix;
}

- (NSUInteger) numberOfGlyphs
{
  return numberOfGlyphs;
}

- (CGFloat) pointSize
{
  return matrix[0];
}

- (NSString*) fontName
{
  return fontName;
}

- (BOOL) isBaseFont
{
  return isBaseFont;
}

- (BOOL) isFixedPitch
{
  return isFixedPitch;
}

- (CGFloat) ascender
{
  return ascender;
}

- (CGFloat) descender
{
  return descender;
}

- (CGFloat) capHeight
{
  return capHeight;
}

- (CGFloat) italicAngle
{
  return italicAngle;
}

- (NSSize) maximumAdvancement
{
  return maximumAdvancement;
}

- (NSSize) minimumAdvancement
{
  return minimumAdvancement;
}

- (CGFloat) underlinePosition
{
  return underlinePosition;
}

- (CGFloat) underlineThickness
{
  return underlineThickness;
}

- (CGFloat) xHeight
{
  return xHeight;
}

- (CGFloat) defaultLineHeightForFont
{
  /*
  In the absence of a more accurate line height from the font itself, we
  use ascender_height+descender_height (note that descender is negative
  below the baseline). This matches what other systems do, and it matches
  the font-provided line height in most cases. (Note that the ascender
  height usually includes a bit of space above the top of the actual
  glyphs, so we get some inter-line spacing anyway.)

  This calculation should match the baseline calculation in
  GSHorizontalTypesetter, or text will look odd.
  */
  return [self ascender] - [self descender];
}

- (NSSize) advancementForGlyph: (NSGlyph)aGlyph
{
  return NSMakeSize (0,0);
}

- (NSRect) boundingRectForGlyph: (NSGlyph)aGlyph
{
  return NSZeroRect;
}

- (BOOL) glyphIsEncoded: (NSGlyph)aGlyph;
{
  // FIXME: This is a hack for aGlyph == theChar fonts.
  if (coveredCharacterSet == nil)
    {
      [self coveredCharacterSet];
    }
  return [coveredCharacterSet characterIsMember: (unichar)aGlyph];
}

- (NSMultibyteGlyphPacking) glyphPacking
{
  return NSOneByteGlyphPacking;
}

- (NSGlyph) glyphWithName: (NSString*)glyphName
{
  return 0;
}

- (NSPoint) positionOfGlyph: (NSGlyph)curGlyph
	    precededByGlyph: (NSGlyph)prevGlyph
		  isNominal: (BOOL *)nominal
{
  NSSize advance;

  if (nominal)
    *nominal = YES;

  if (curGlyph == NSControlGlyph || prevGlyph == NSControlGlyph)
    return NSZeroPoint;

  if (curGlyph == NSNullGlyph)
    advance = [self advancementForGlyph: prevGlyph];
  else
    // Should check kerning
    advance = [self advancementForGlyph: prevGlyph];

  return NSMakePoint (advance.width, advance.height);
}

- (NSPoint) positionOfGlyph: (NSGlyph)aGlyph
	       forCharacter: (unichar)aChar
	     struckOverRect: (NSRect)aRect
{
  return NSZeroPoint;
}

- (NSPoint) positionOfGlyph: (NSGlyph)aGlyph
	    struckOverGlyph: (NSGlyph)baseGlyph
	       metricsExist: (BOOL *)flag
{
  if (flag)
    *flag = NO;

  return NSZeroPoint;
}

- (NSPoint) positionOfGlyph: (NSGlyph)aGlyph
	     struckOverRect: (NSRect)aRect
	       metricsExist: (BOOL *)flag
{
  if (flag)
    *flag = NO;

  return NSZeroPoint;
}

- (NSPoint) positionOfGlyph: (NSGlyph)aGlyph
	       withRelation: (NSGlyphRelation)relation
		toBaseGlyph: (NSGlyph)baseGlyph
	   totalAdvancement: (NSSize *)offset
	       metricsExist: (BOOL *)flag
{
  NSRect baseRect = [self boundingRectForGlyph: baseGlyph];
  NSPoint point = NSZeroPoint;

  if (flag)
    *flag = NO;

  if (relation == NSGlyphBelow)
    {
      point = baseRect.origin;
    }
  else
    {
      point = NSMakePoint (baseRect.origin.x, NSMaxY (baseRect));
    }

  if (offset)
    {
       NSSize baseSize = [self advancementForGlyph: baseGlyph];
       NSSize aSize = [self advancementForGlyph: aGlyph];

       if (baseSize.width > aSize.width)
	 *offset = baseSize;
       else
	 *offset = aSize;
    }

  return point;
}

- (NSStringEncoding) mostCompatibleStringEncoding
{
  return mostCompatibleStringEncoding;
}

- (CGFloat) widthOfString: (NSString*)string
{
  return 0;
}

- (NSFontTraitMask) traits
{
  return traits;
}

- (int) weight
{
  return weight;
}

-(void) appendBezierPathWithGlyphs: (NSGlyph *)glyphs
			     count: (int)count
		      toBezierPath: (NSBezierPath *)path
{
  [self subclassResponsibility: _cmd];
}

- (NSGlyph) glyphForCharacter: (unichar)theChar
{
  // Hack to get most font backends working
  if ([self glyphIsEncoded: (NSGlyph)theChar])
    return (NSGlyph)theChar;
  else
    return NSNullGlyph;
}

- (NSFontDescriptor*) fontDescriptor
{
  if (fontDescriptor == nil)
    {
      // Create a new one
      if ((matrix[0] == matrix[3]) && (matrix[1] == 0.0) &&
          (matrix[2] == 0.0) && (matrix[4] == 0.0) && (matrix[5] == 0.0))
        {
          ASSIGN(fontDescriptor, [NSFontDescriptor fontDescriptorWithName: fontName
                                                                     size: matrix[0]]);
        }
      else
        {
          NSAffineTransform *transform = [NSAffineTransform new];
          NSAffineTransformStruct ats;
          NSDictionary *attributes;

          ats.m11 = matrix[0];
          ats.m12 = matrix[1];
          ats.m21 = matrix[2];
          ats.m22 = matrix[3];
          ats.tX = matrix[4];
          ats.tY = matrix[5];
          [transform setTransformStruct: ats];

          attributes = [NSDictionary dictionaryWithObjectsAndKeys:
                                       fontName, NSFontNameAttribute,
                                     transform, NSFontMatrixAttribute,
                                     nil];
          RELEASE(transform);
          fontDescriptor = [[NSFontDescriptor alloc] initWithFontAttributes: attributes];
        }
    }
  return fontDescriptor;
}

@end