Struct rute::auto::font::Font

source ·

pub struct Font<'a> { /* private fields */ }

Expand description

Notice these docs are heavy WIP and not very relevent yet

When you create a QFont object you specify various attributes that you want the font to have. Qt will use the font with the specified attributes, or if no matching font exists, Qt will use the closest matching installed font. The attributes of the font that is actually used are retrievable from a QFontInfo object. If the window system provides an exact match exactMatch() returns true. Use QFontMetrics to get measurements, e.g. the pixel length of a string using QFontMetrics::width().

Note that a QGuiApplication instance must exist before a QFont can be used. You can set the application’s default font with QGuiApplication::setFont().

If a chosen font does not include all the characters that need to be displayed, QFont will try to find the characters in the nearest equivalent fonts. When a QPainter draws a character from a font the QFont will report whether or not it has the character; if it does not, QPainter will draw an unfilled square.

Create QFonts like this:

The attributes set in the constructor can also be set later, e.g. setFamily(), setPointSize(), setPointSizeF(), setWeight() and setItalic(). The remaining attributes must be set after contstruction, e.g. setBold(), setUnderline(), setOverline(), setStrikeOut() and setFixedPitch(). QFontInfo objects should be created after the font’s attributes have been set. A QFontInfo object will not change, even if you change the font’s attributes. The corresponding functions, e.g. family(), pointSize(), etc., return the values that were set, even though the values used may differ. The actual values are available from a QFontInfo object.

If the requested font family is unavailable you can influence the font matching algorithm by choosing a particular QFont::StyleHint and QFont::StyleStrategy with setStyleHint(). The default family (corresponding to the current style hint) is returned by defaultFamily().

The font-matching algorithm has a lastResortFamily() and lastResortFont() in cases where a suitable match cannot be found. You can provide substitutions for font family names using insertSubstitution() and insertSubstitutions(). Substitutions can be removed with removeSubstitutions(). Use substitute() to retrieve a family’s first substitute, or the family name itself if it has no substitutes. Use substitutes() to retrieve a list of a family’s substitutes (which may be empty).

Every QFont has a key() which you can use, for example, as the key in a cache or dictionary. If you want to store a user’s font preferences you could use QSettings, writing the font information with toString() and reading it back with fromString(). The operator<<() and operator>>() functions are also available, but they work on a data stream.

It is possible to set the height of characters shown on the screen to a specified number of pixels with setPixelSize(); however using setPointSize() has a similar effect and provides device independence.

Loading fonts can be expensive, especially on X11. QFont contains extensive optimizations to make the copying of QFont objects fast, and to cache the results of the slow window system functions it depends upon.

The font matching algorithm works as follows:

The specified font family is searched for.
If not found, the styleHint() is used to select a replacement family.
Each replacement font family is searched for.
If none of these are found or there was no styleHint(), “helvetica” will be searched for.
If “helvetica” isn’t found Qt will try the lastResortFamily().
If the lastResortFamily() isn’t found Qt will try the lastResortFont() which will always return a name of some kind.

Note that the actual font matching algorithm varies from platform to platform.

In Windows a request for the font is automatically changed to , an improved version of Courier that allows for smooth scaling. The older bitmap font can be selected by setting the PreferBitmap style strategy (see setStyleStrategy()).

Once a font is found, the remaining attributes are matched in order of priority:

fixedPitch()
pointSize() (see below)
weight()
style()

If you have a font which matches on family, even if none of the other attributes match, this font will be chosen in preference to a font which doesn’t match on family but which does match on the other attributes. This is because font family is the dominant search criteria.

The point size is defined to match if it is within 20% of the requested point size. When several fonts match and are only distinguished by point size, the font with the closest point size to the one requested will be chosen.

The actual family, font size, weight and other font attributes used for drawing text will depend on what’s available for the chosen family under the window system. A QFontInfo object can be used to determine the actual values used for drawing the text.

Examples:

If you had both an Adobe and a Cronyx Helvetica, you might get either.

You can specify the foundry you want in the family name. The font f in the above example will be set to .

To determine the attributes of the font actually used in the window system, use a QFontInfo object, e.g.

To find out font metrics use a QFontMetrics object, e.g.

For more general information on fonts, see the comp.fonts FAQ

Information on encodings can be found from Roman Czyborra’s page.

See also: [FontMetrics] FontInfo [FontDatabase] {Character Map Example}

Licence

The documentation is an adoption of the original Qt Documentation and provided herein is licensed under the terms of the GNU Free Documentation License version 1.3 as published by the Free Software Foundation.

Struct rute::auto::font::Font

Licence

Implementations

impl<'a> Font<'a>

pub fn new() -> Font<'a>

pub fn swap<F: FontTrait<'a>>(&self, other: &F) -> &Self

pub fn family(&self) -> String

pub fn set_family(&self, arg0: &str) -> &Self

pub fn style_name(&self) -> String

pub fn set_style_name(&self, arg0: &str) -> &Self

pub fn point_size(&self) -> i32

pub fn set_point_size(&self, arg0: i32) -> &Self

pub fn point_size_f(&self) -> f32

pub fn set_point_size_f(&self, arg0: f32) -> &Self

pub fn pixel_size(&self) -> i32

pub fn set_pixel_size(&self, arg0: i32) -> &Self

pub fn weight(&self) -> i32

pub fn set_weight(&self, arg0: i32) -> &Self

pub fn bold(&self) -> bool

pub fn set_bold(&self, arg0: bool) -> &Self

pub fn italic(&self) -> bool

pub fn set_italic(&self, b: bool) -> &Self

pub fn underline(&self) -> bool

pub fn set_underline(&self, arg0: bool) -> &Self

pub fn overline(&self) -> bool

pub fn set_overline(&self, arg0: bool) -> &Self

pub fn fixed_pitch(&self) -> bool

pub fn set_fixed_pitch(&self, arg0: bool) -> &Self

pub fn kerning(&self) -> bool

pub fn set_kerning(&self, arg0: bool) -> &Self

pub fn style_hint(&self) -> StyleHint

pub fn set_style_hint(&self, arg0: StyleHint, arg1: StyleStrategy) -> &Self

pub fn letter_spacing(&self) -> f32

pub fn letter_spacing_type(&self) -> SpacingType

pub fn set_letter_spacing(&self, stype: SpacingType, spacing: f32) -> &Self

pub fn word_spacing(&self) -> f32

pub fn set_word_spacing(&self, spacing: f32) -> &Self

pub fn set_capitalization(&self, arg0: Capitalization) -> &Self

pub fn capitalization(&self) -> Capitalization

pub fn set_hinting_preference( &self, hinting_preference: HintingPreference) -> &Self

pub fn hinting_preference(&self) -> HintingPreference

pub fn raw_mode(&self) -> bool

pub fn set_raw_mode(&self, arg0: bool) -> &Self

pub fn exact_match(&self) -> bool

pub fn is_copy_of<F: FontTrait<'a>>(&self, arg0: &F) -> bool

pub fn set_raw_name(&self, arg0: &str) -> &Self

pub fn raw_name(&self) -> String

pub fn key(&self) -> String

pub fn substitute(arg0: &str) -> String

pub fn insert_substitution(arg0: &str, arg1: &str)

pub fn remove_substitutions(arg0: &str)

pub fn initialize()

pub fn cleanup()

pub fn cache_statistics()

pub fn default_family(&self) -> String

pub fn last_resort_family(&self) -> String

pub fn last_resort_font(&self) -> String

pub fn resolve<F: FontTrait<'a>>(&self, arg0: &F) -> Font<'_>

pub fn resolve_2(&self) -> u64

pub fn resolve_3(&self, mask: u64) -> &Self

pub fn build(&self) -> Self

Trait Implementations

impl<'a> Clone for Font<'a>

fn clone(&self) -> Font<'a>

fn clone_from(&mut self, source: &Self)

impl<'a> FontTrait<'a> for Font<'a>

Auto Trait Implementations

impl<'a> !RefUnwindSafe for Font<'a>

impl<'a> !Send for Font<'a>

impl<'a> !Sync for Font<'a>

impl<'a> Unpin for Font<'a>

impl<'a> !UnwindSafe for Font<'a>

Blanket Implementations

impl<T> Any for Twhere T: 'static + ?Sized,

fn type_id(&self) -> TypeId

impl<T> Borrow<T> for Twhere T: ?Sized,

fn borrow(&self) -> &T

impl<T> BorrowMut<T> for Twhere T: ?Sized,

fn borrow_mut(&mut self) -> &mut T

impl<T> From<T> for T

pub fn set_hinting_preference(
&self,
hinting_preference: HintingPreference
) -> &Self

impl<T> Any for Twhere
T: 'static + ?Sized,

impl<T> Borrow<T> for Twhere
T: ?Sized,

impl<T> BorrowMut<T> for Twhere
T: ?Sized,

impl<T, U> Into<U> for Twhere
U: From<T>,

impl<T> ToOwned for Twhere
T: Clone,

impl<T, U> TryFrom<U> for Twhere
U: Into<T>,

impl<T, U> TryInto<U> for Twhere
U: TryFrom<T>,