libui/darwin/_old_drawtext.m

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// 6 september 2015
#import "uipriv_darwin.h"
// TODO
#define complain(...) implbug(__VA_ARGS__)
// TODO double-check that we are properly handling allocation failures (or just toll free bridge from cocoa)
struct uiDrawFontFamilies {
CFArrayRef fonts;
};
uiDrawFontFamilies *uiDrawListFontFamilies(void)
{
uiDrawFontFamilies *ff;
ff = uiNew(uiDrawFontFamilies);
ff->fonts = CTFontManagerCopyAvailableFontFamilyNames();
if (ff->fonts == NULL)
implbug("error getting available font names (no reason specified) (TODO)");
return ff;
}
int uiDrawFontFamiliesNumFamilies(uiDrawFontFamilies *ff)
{
return CFArrayGetCount(ff->fonts);
}
char *uiDrawFontFamiliesFamily(uiDrawFontFamilies *ff, int n)
{
CFStringRef familystr;
char *family;
familystr = (CFStringRef) CFArrayGetValueAtIndex(ff->fonts, n);
// toll-free bridge
family = uiDarwinNSStringToText((NSString *) familystr);
// Get Rule means we do not free familystr
return family;
}
void uiDrawFreeFontFamilies(uiDrawFontFamilies *ff)
{
CFRelease(ff->fonts);
uiFree(ff);
}
struct uiDrawTextFont {
CTFontRef f;
};
uiDrawTextFont *mkTextFont(CTFontRef f, BOOL retain)
{
uiDrawTextFont *font;
font = uiNew(uiDrawTextFont);
font->f = f;
if (retain)
CFRetain(font->f);
return font;
}
uiDrawTextFont *mkTextFontFromNSFont(NSFont *f)
{
// toll-free bridging; we do retain, though
return mkTextFont((CTFontRef) f, YES);
}
static CFMutableDictionaryRef newAttrList(void)
{
CFMutableDictionaryRef attr;
attr = CFDictionaryCreateMutable(NULL, 0, &kCFTypeDictionaryKeyCallBacks, &kCFTypeDictionaryValueCallBacks);
if (attr == NULL)
complain("error creating attribute dictionary in newAttrList()()");
return attr;
}
static void addFontFamilyAttr(CFMutableDictionaryRef attr, const char *family)
{
CFStringRef cfstr;
cfstr = CFStringCreateWithCString(NULL, family, kCFStringEncodingUTF8);
if (cfstr == NULL)
complain("error creating font family name CFStringRef in addFontFamilyAttr()");
CFDictionaryAddValue(attr, kCTFontFamilyNameAttribute, cfstr);
CFRelease(cfstr); // dictionary holds its own reference
}
static void addFontSizeAttr(CFMutableDictionaryRef attr, double size)
{
CFNumberRef n;
n = CFNumberCreate(NULL, kCFNumberDoubleType, &size);
CFDictionaryAddValue(attr, kCTFontSizeAttribute, n);
CFRelease(n);
}
#if 0
TODO
// See http://stackoverflow.com/questions/4810409/does-coretext-support-small-caps/4811371#4811371 and https://git.gnome.org/browse/pango/tree/pango/pangocoretext-fontmap.c for what these do
// And fortunately, unlike the traits (see below), unmatched features are simply ignored without affecting the other features :D
static void addFontSmallCapsAttr(CFMutableDictionaryRef attr)
{
CFMutableArrayRef outerArray;
CFMutableDictionaryRef innerDict;
CFNumberRef numType, numSelector;
int num;
outerArray = CFArrayCreateMutable(NULL, 0, &kCFTypeArrayCallBacks);
if (outerArray == NULL)
complain("error creating outer CFArray for adding small caps attributes in addFontSmallCapsAttr()");
// Apple's headers say these are deprecated, but a few fonts still rely on them
num = kLetterCaseType;
numType = CFNumberCreate(NULL, kCFNumberIntType, &num);
num = kSmallCapsSelector;
numSelector = CFNumberCreate(NULL, kCFNumberIntType, &num);
innerDict = newAttrList();
CFDictionaryAddValue(innerDict, kCTFontFeatureTypeIdentifierKey, numType);
CFRelease(numType);
CFDictionaryAddValue(innerDict, kCTFontFeatureSelectorIdentifierKey, numSelector);
CFRelease(numSelector);
CFArrayAppendValue(outerArray, innerDict);
CFRelease(innerDict); // and likewise for CFArray
// these are the non-deprecated versions of the above; some fonts have these instead
num = kLowerCaseType;
numType = CFNumberCreate(NULL, kCFNumberIntType, &num);
num = kLowerCaseSmallCapsSelector;
numSelector = CFNumberCreate(NULL, kCFNumberIntType, &num);
innerDict = newAttrList();
CFDictionaryAddValue(innerDict, kCTFontFeatureTypeIdentifierKey, numType);
CFRelease(numType);
CFDictionaryAddValue(innerDict, kCTFontFeatureSelectorIdentifierKey, numSelector);
CFRelease(numSelector);
CFArrayAppendValue(outerArray, innerDict);
CFRelease(innerDict); // and likewise for CFArray
CFDictionaryAddValue(attr, kCTFontFeatureSettingsAttribute, outerArray);
CFRelease(outerArray);
}
#endif
// Named constants for these were NOT added until 10.11, and even then they were added as external symbols instead of macros, so we can't use them directly :(
// kode54 got these for me before I had access to El Capitan; thanks to him.
#define ourNSFontWeightUltraLight -0.800000
#define ourNSFontWeightThin -0.600000
#define ourNSFontWeightLight -0.400000
#define ourNSFontWeightRegular 0.000000
#define ourNSFontWeightMedium 0.230000
#define ourNSFontWeightSemibold 0.300000
#define ourNSFontWeightBold 0.400000
#define ourNSFontWeightHeavy 0.560000
#define ourNSFontWeightBlack 0.620000
// Now remember what I said earlier about having to add the small caps traits after calling the above? This gets a dictionary back so we can do so.
CFMutableDictionaryRef extractAttributes(CTFontDescriptorRef desc)
{
CFDictionaryRef dict;
CFMutableDictionaryRef mdict;
dict = CTFontDescriptorCopyAttributes(desc);
// this might not be mutable, so make a mutable copy
mdict = CFDictionaryCreateMutableCopy(NULL, 0, dict);
CFRelease(dict);
return mdict;
}
uiDrawTextFont *uiDrawLoadClosestFont(const uiDrawTextFontDescriptor *desc)
{
CTFontRef f;
CFMutableDictionaryRef attr;
CTFontDescriptorRef cfdesc;
attr = newAttrList();
addFontFamilyAttr(attr, desc->Family);
addFontSizeAttr(attr, desc->Size);
// now we have to do the traits matching, so create a descriptor, match the traits, and then get the attributes back
cfdesc = CTFontDescriptorCreateWithAttributes(attr);
// TODO release attr?
cfdesc = matchTraits(cfdesc, desc->Weight, desc->Italic, desc->Stretch);
// specify the initial size again just to be safe
f = CTFontCreateWithFontDescriptor(cfdesc, desc->Size, NULL);
// TODO release cfdesc?
return mkTextFont(f, NO); // we hold the initial reference; no need to retain again
}
void uiDrawFreeTextFont(uiDrawTextFont *font)
{
CFRelease(font->f);
uiFree(font);
}
uintptr_t uiDrawTextFontHandle(uiDrawTextFont *font)
{
return (uintptr_t) (font->f);
}
void uiDrawTextFontDescribe(uiDrawTextFont *font, uiDrawTextFontDescriptor *desc)
{
// TODO
}
// text sizes and user space points are identical:
// - https://developer.apple.com/library/mac/documentation/TextFonts/Conceptual/CocoaTextArchitecture/TypoFeatures/TextSystemFeatures.html#//apple_ref/doc/uid/TP40009459-CH6-51627-BBCCHIFF text points are 72 per inch
// - https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/CocoaDrawingGuide/Transforms/Transforms.html#//apple_ref/doc/uid/TP40003290-CH204-SW5 user space points are 72 per inch
void uiDrawTextFontGetMetrics(uiDrawTextFont *font, uiDrawTextFontMetrics *metrics)
{
metrics->Ascent = CTFontGetAscent(font->f);
metrics->Descent = CTFontGetDescent(font->f);
metrics->Leading = CTFontGetLeading(font->f);
metrics->UnderlinePos = CTFontGetUnderlinePosition(font->f);
metrics->UnderlineThickness = CTFontGetUnderlineThickness(font->f);
}
struct uiDrawTextLayout {
CFMutableAttributedStringRef mas;
CFRange *charsToRanges;
double width;
};
uiDrawTextLayout *uiDrawNewTextLayout(const char *str, uiDrawTextFont *defaultFont, double width)
{
uiDrawTextLayout *layout;
CFAttributedStringRef immutable;
CFMutableDictionaryRef attr;
CFStringRef backing;
CFIndex i, j, n;
layout = uiNew(uiDrawTextLayout);
// TODO docs say we need to use a different set of key callbacks
// TODO see if the font attribute key callbacks need to be the same
attr = newAttrList();
// this will retain defaultFont->f; no need to worry
CFDictionaryAddValue(attr, kCTFontAttributeName, defaultFont->f);
immutable = CFAttributedStringCreate(NULL, (CFStringRef) [NSString stringWithUTF8String:str], attr);
if (immutable == NULL)
complain("error creating immutable attributed string in uiDrawNewTextLayout()");
CFRelease(attr);
layout->mas = CFAttributedStringCreateMutableCopy(NULL, 0, immutable);
if (layout->mas == NULL)
complain("error creating attributed string in uiDrawNewTextLayout()");
CFRelease(immutable);
uiDrawTextLayoutSetWidth(layout, width);
// unfortunately the CFRanges for attributes expect UTF-16 codepoints
// we want graphemes
// fortunately CFStringGetRangeOfComposedCharactersAtIndex() is here for us
// https://developer.apple.com/library/mac/documentation/Cocoa/Conceptual/Strings/Articles/stringsClusters.html says that this does work on all multi-codepoint graphemes (despite the name), and that this is the preferred function for this particular job anyway
backing = CFAttributedStringGetString(layout->mas);
n = CFStringGetLength(backing);
// allocate one extra, just to be safe
layout->charsToRanges = (CFRange *) uiAlloc((n + 1) * sizeof (CFRange), "CFRange[]");
i = 0;
j = 0;
while (i < n) {
CFRange range;
range = CFStringGetRangeOfComposedCharactersAtIndex(backing, i);
i = range.location + range.length;
layout->charsToRanges[j] = range;
j++;
}
// and set the last one
layout->charsToRanges[j].location = i;
layout->charsToRanges[j].length = 0;
return layout;
}
void uiDrawFreeTextLayout(uiDrawTextLayout *layout)
{
uiFree(layout->charsToRanges);
CFRelease(layout->mas);
uiFree(layout);
}
void uiDrawTextLayoutSetWidth(uiDrawTextLayout *layout, double width)
{
layout->width = width;
}
struct framesetter {
CTFramesetterRef fs;
CFMutableDictionaryRef frameAttrib;
CGSize extents;
};
// TODO CTFrameProgression for RTL/LTR
// TODO kCTParagraphStyleSpecifierMaximumLineSpacing, kCTParagraphStyleSpecifierMinimumLineSpacing, kCTParagraphStyleSpecifierLineSpacingAdjustment for line spacing
static void mkFramesetter(uiDrawTextLayout *layout, struct framesetter *fs)
{
CFRange fitRange;
CGFloat width;
fs->fs = CTFramesetterCreateWithAttributedString(layout->mas);
if (fs->fs == NULL)
complain("error creating CTFramesetter object in mkFramesetter()");
// TODO kCTFramePathWidthAttributeName?
fs->frameAttrib = NULL;
width = layout->width;
if (layout->width < 0)
width = CGFLOAT_MAX;
// TODO these seem to be floor()'d or truncated?
fs->extents = CTFramesetterSuggestFrameSizeWithConstraints(fs->fs,
CFRangeMake(0, 0),
fs->frameAttrib,
CGSizeMake(width, CGFLOAT_MAX),
&fitRange); // not documented as accepting NULL
}
static void freeFramesetter(struct framesetter *fs)
{
if (fs->frameAttrib != NULL)
CFRelease(fs->frameAttrib);
CFRelease(fs->fs);
}
// LONGTERM allow line separation and leading to be factored into a wrapping text layout
// TODO reconcile differences in character wrapping on platforms
void uiDrawTextLayoutExtents(uiDrawTextLayout *layout, double *width, double *height)
{
struct framesetter fs;
mkFramesetter(layout, &fs);
*width = fs.extents.width;
*height = fs.extents.height;
freeFramesetter(&fs);
}
// Core Text doesn't draw onto a flipped view correctly; we have to do this
// see the iOS bits of the first example at https://developer.apple.com/library/mac/documentation/StringsTextFonts/Conceptual/CoreText_Programming/LayoutOperations/LayoutOperations.html#//apple_ref/doc/uid/TP40005533-CH12-SW1 (iOS is naturally flipped)
// TODO how is this affected by the CTM?
static void prepareContextForText(CGContextRef c, CGFloat cheight, double *y)
{
CGContextSaveGState(c);
CGContextTranslateCTM(c, 0, cheight);
CGContextScaleCTM(c, 1.0, -1.0);
CGContextSetTextMatrix(c, CGAffineTransformIdentity);
// wait, that's not enough; we need to offset y values to account for our new flipping
*y = cheight - *y;
}
// TODO placement is incorrect for Helvetica
void doDrawText(CGContextRef c, CGFloat cheight, double x, double y, uiDrawTextLayout *layout)
{
struct framesetter fs;
CGRect rect;
CGPathRef path;
CTFrameRef frame;
prepareContextForText(c, cheight, &y);
mkFramesetter(layout, &fs);
// oh, and since we're flipped, y is the bottom-left coordinate of the rectangle, not the top-left
// since we are flipped, we subtract
y -= fs.extents.height;
rect.origin = CGPointMake(x, y);
rect.size = fs.extents;
path = CGPathCreateWithRect(rect, NULL);
frame = CTFramesetterCreateFrame(fs.fs,
CFRangeMake(0, 0),
path,
fs.frameAttrib);
if (frame == NULL)
complain("error creating CTFrame object in doDrawText()");
CTFrameDraw(frame, c);
CFRelease(frame);
CFRelease(path);
freeFramesetter(&fs);
CGContextRestoreGState(c);
}
// LONGTERM provide an equivalent to CTLineGetTypographicBounds() on uiDrawTextLayout?
// LONGTERM keep this for later features and documentation purposes
#if 0
w = CTLineGetTypographicBounds(line, &ascent, &descent, NULL);
// though CTLineGetTypographicBounds() returns 0 on error, it also returns 0 on an empty string, so we can't reasonably check for error
CFRelease(line);
// LONGTERM provide a way to get the image bounds as a separate function later
bounds = CTLineGetImageBounds(line, c);
// though CTLineGetImageBounds() returns CGRectNull on error, it also returns CGRectNull on an empty string, so we can't reasonably check for error
// CGContextSetTextPosition() positions at the baseline in the case of CTLineDraw(); we need the top-left corner instead
CTLineGetTypographicBounds(line, &yoff, NULL, NULL);
// remember that we're flipped, so we subtract
y -= yoff;
CGContextSetTextPosition(c, x, y);
#endif
static CFRange charsToRange(uiDrawTextLayout *layout, int startChar, int endChar)
{
CFRange start, end;
CFRange out;
start = layout->charsToRanges[startChar];
end = layout->charsToRanges[endChar];
out.location = start.location;
out.length = end.location - start.location;
return out;
}
#define rangeToCFRange() charsToRange(layout, startChar, endChar)
void uiDrawTextLayoutSetColor(uiDrawTextLayout *layout, int startChar, int endChar, double r, double g, double b, double a)
{
CGColorSpaceRef colorspace;
CGFloat components[4];
CGColorRef color;
// for consistency with windows, use sRGB
colorspace = CGColorSpaceCreateWithName(kCGColorSpaceSRGB);
components[0] = r;
components[1] = g;
components[2] = b;
components[3] = a;
color = CGColorCreate(colorspace, components);
CGColorSpaceRelease(colorspace);
CFAttributedStringSetAttribute(layout->mas,
rangeToCFRange(),
kCTForegroundColorAttributeName,
color);
CGColorRelease(color); // TODO safe?
}