UXFont

UXFont is a font descriptor: a family, a point size, and the bold and italic traits. A font chooser edits this value and text drawing carries it.

Glyph rasterisation and the list of available families belong to the backend. This type touches neither, so it works the same on GEM and macOS, and it can be compared, stored and passed around freely.

#use <UXKit>            // or #import "UXFont.xc"

Overview

UXFont* base = UXFont.make((u8*)"Helvetica", 12);
UXFont* head = base.bolded().withSize(18);

Every derivation returns a new font. Nothing mutates:

base.bolded();          // Helvetica 12 Bold
base;                   // Helvetica 12   — unchanged

The type is built around this property. Whoever else holds a reference to a font handed to a label cannot change it underneath the label, so there is no defensive copying and no question about who owns a style.

Derivations chain, which is how a style menu composes:

base.bolded().italicized().withSize(14);    // Helvetica 14 Bold Italic

Topics

make · makeTraits · dup · withSize · withFamily · bolded · unbolded · italicized · togglingBold · togglingItalic · scaledBy · isBold · isItalic · isEqualTo · description

make

static UXFont* make(u8* family, i16 size)

Family and point size, no traits. The default font is System 12.

makeTraits

static UXFont* makeTraits(u8* family, i16 size, bool bold, bool italic)

Sets all four at once. Use it to restore a saved font, where the traits are known rather than derived.

dup

UXFont* dup(void)

An independent copy. Every derivation below is dup plus one change, so none of them can affect the receiver.

withSize

UXFont* withSize(i16 s)

withFamily

UXFont* withFamily(u8* fam)

bolded / unbolded

UXFont* bolded(void)
UXFont* unbolded(void)

Set the trait, regardless of its previous value.

italicized

UXFont* italicized(void)

Sets italic on, regardless of its previous value.

togglingBold / togglingItalic

UXFont* togglingBold(void)
UXFont* togglingItalic(void)

Flip the trait. A Bold or Italic menu item uses this pair: the menu does not need to know the current state, and applying it twice returns the original font.

UXFont* b = base.togglingBold();       // Helvetica 12 Bold
b.togglingBold();                      // Helvetica 12

scaledBy

UXFont* scaledBy(i16 pct)

A percentage of the current size, integer-rounded: scaledBy(150) on 12 gives 18. Use it to make text one step larger without knowing the base size.

isBold / isItalic

bool isBold(void)
bool isItalic(void)

isEqualTo

bool isEqualTo(UXFont* o)

Value equality: family, size and both traits. Two separately constructed Helvetica 12s are equal:

UXFont* a = UXFont.make((u8*)"Helvetica", 12);
UXFont* b = UXFont.make((u8*)"Helvetica", 12);
a.isEqualTo(b)              // true
a.isEqualTo(a.bolded())     // false

description

u8* description(void)

A human-readable label such as "Helvetica 12 Bold Italic". Traits appear only when set, so a plain font is "Helvetica 12". A chooser’s preview line and a font menu item show this string.

Example

#import <Stdio.xc>
#import "UXFont.xc"

void main(void) {
    UXFont* base = UXFont.make((u8*)"Helvetica", 12);

    base.bolded();                                 // Helvetica 12 Bold
    base.italicized();                             // Helvetica 12 Italic
    base.withSize(18);                             // Helvetica 18
    base.scaledBy(150);                            // Helvetica 18
    base;                                          // Helvetica 12 — untouched

    base.bolded().italicized().withSize(14);       // Helvetica 14 Bold Italic

    UXFont* b = base.togglingBold();               // Helvetica 12 Bold
    b.togglingBold();                              // Helvetica 12

    UXFont* other = UXFont.make((u8*)"Helvetica", 12);
    base.isEqualTo(other);                         // true
    base.isEqualTo(base.bolded());                 // false
}

The full program is website/site/examples/uxkit/font.xc. The doc-examples gate compiles it, and the comments are its real output.

Conforms to

A plain class (not an Object subclass)