Struct druid::text::FontDescriptor

source · 
pub struct FontDescriptor {
    pub family: FontFamily,
    pub size: f64,
    pub weight: FontWeight,
    pub style: FontStyle,
}
Expand description

A collection of attributes that describe a font.

This is provided as a convenience; library consumers may wish to have a single type that represents a specific font face at a specific size.

Fields§

§family: FontFamily

The font’s FontFamily.

§size: f64

The font’s size.

§weight: FontWeight

The font’s FontWeight.

§style: FontStyle

The font’s FontStyle.

Implementations§

source§

impl FontDescriptor

source

pub const fn new(family: FontFamily) -> Self

Create a new descriptor with the provided FontFamily.

Examples found in repository?
examples/styled_text.rs (line 107)
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160

fn ui_builder() -> impl Widget<AppData> {
    let my_painter = Painter::new(|ctx, _, _| {
        let bounds = ctx.size().to_rect();
        if ctx.is_hot() {
            ctx.fill(bounds, &Color::rgba8(0, 0, 0, 128));
        }

        if ctx.is_active() {
            ctx.stroke(bounds, &Color::WHITE, 2.0);
        }
    });

    // This is Druid's default text style.
    // It's set by theme::LABEL_COLOR and theme::UI_FONT
    let label =
        Label::new(|data: &String, _env: &_| format!("Default: {data}")).lens(AppData::text);

    // The text_color, text_size, and font builder methods can override the
    // defaults provided by the theme by passing in a Key or a concrete value.
    //
    // In this example, text_color receives a Key from the theme, text_size
    // gets a custom key which we set with the env_scope wrapper, and the
    // default font key (theme::FONT_NAME) is overridden in the env_scope
    // wrapper. (Like text_color and text_size, the font can be set using the
    // with_font builder method, but overriding here makes it easy to fall back
    // to the default font)
    let styled_label = Label::new(|data: &AppData, _env: &_| format!("{data}"))
        .with_text_color(theme::PRIMARY_LIGHT)
        .with_font(MY_CUSTOM_FONT)
        .background(my_painter)
        .on_click(|_, data, _| {
            data.size *= 1.1;
        })
        .env_scope(|env: &mut druid::Env, data: &AppData| {
            let new_font = if data.mono {
                FontDescriptor::new(FontFamily::MONOSPACE)
            } else {
                FontDescriptor::new(FontFamily::SYSTEM_UI)
            }
            .with_size(data.size);
            env.set(MY_CUSTOM_FONT, new_font);
        });

    let labels = Scroll::new(
        Flex::column()
            .cross_axis_alignment(CrossAxisAlignment::Start)
            .with_child(label)
            .with_default_spacer()
            .with_child(styled_label),
    )
    .expand_height()
    .fix_width(COLUMN_WIDTH);

    let stepper = Stepper::new()
        .with_range(0.0, 100.0)
        .with_step(1.0)
        .with_wraparound(false)
        .lens(AppData::size);

    // TODO: Replace Parse usage with TextBox::with_formatter
    #[allow(deprecated)]
    let stepper_textbox = LensWrap::new(
        Parse::new(TextBox::new()),
        AppData::size.map(|x| Some(*x), |x, y| *x = y.unwrap_or(24.0)),
    );

    let mono_checkbox = Checkbox::new("Monospace").lens(AppData::mono);
    let stepper_row = Flex::row()
        .with_child(stepper_textbox)
        .with_child(stepper)
        .with_default_spacer()
        .with_child(mono_checkbox);

    let input = TextBox::multiline()
        .with_placeholder("Your sample text here :)")
        .fix_width(COLUMN_WIDTH)
        .fix_height(140.0)
        .lens(AppData::text);

    Flex::column()
        .main_axis_alignment(MainAxisAlignment::Center)
        .with_default_spacer()
        .with_flex_child(labels, 1.0)
        .with_default_spacer()
        .with_child(input)
        .with_default_spacer()
        .with_child(stepper_row)
        .with_default_spacer()
}
More examples
Hide additional examples
examples/custom_widget.rs (line 119)
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153

    fn paint(&mut self, ctx: &mut PaintCtx, data: &String, env: &Env) {
        // Clear the whole widget with the color of your choice
        // (ctx.size() returns the size of the layout rect we're painting in)
        // Note: ctx also has a `clear` method, but that clears the whole context,
        // and we only want to clear this widget's area.
        let size = ctx.size();
        let rect = size.to_rect();
        ctx.fill(rect, &Color::WHITE);

        // We can paint with a Z index, this indicates that this code will be run
        // after the rest of the painting. Painting with z-index is done in order,
        // so first everything with z-index 1 is painted and then with z-index 2 etc.
        // As you can see this(red) curve is drawn on top of the green curve
        ctx.paint_with_z_index(1, move |ctx| {
            let mut path = BezPath::new();
            path.move_to((0.0, size.height));
            path.quad_to((40.0, 50.0), (size.width, 0.0));
            // Create a color
            let stroke_color = Color::rgb8(128, 0, 0);
            // Stroke the path with thickness 1.0
            ctx.stroke(path, &stroke_color, 5.0);
        });

        // Create an arbitrary bezier path
        let mut path = BezPath::new();
        path.move_to(Point::ORIGIN);
        path.quad_to((40.0, 50.0), (size.width, size.height));
        // Create a color
        let stroke_color = Color::rgb8(0, 128, 0);
        // Stroke the path with thickness 5.0
        ctx.stroke(path, &stroke_color, 5.0);

        // Rectangles: the path for practical people
        let rect = Rect::from_origin_size((10.0, 10.0), (100.0, 100.0));
        // Note the Color:rgba8 which includes an alpha channel (7F in this case)
        let fill_color = Color::rgba8(0x00, 0x00, 0x00, 0x7F);
        ctx.fill(rect, &fill_color);

        // Text is easy; in real use TextLayout should either be stored in the
        // widget and reused, or a label child widget to manage it all.
        // This is one way of doing it, you can also use a builder-style way.
        let mut layout = TextLayout::<String>::from_text(data);
        layout.set_font(FontDescriptor::new(FontFamily::SERIF).with_size(24.0));
        layout.set_text_color(fill_color);
        layout.rebuild_if_needed(ctx.text(), env);

        // Let's rotate our text slightly. First we save our current (default) context:
        ctx.with_save(|ctx| {
            // Now we can rotate the context (or set a clip path, for instance):
            // This makes it so that anything drawn after this (in the closure) is
            // transformed.
            // The transformation is in radians, but be aware it transforms the canvas,
            // not just the part you are drawing. So we draw at (80.0, 40.0) on the rotated
            // canvas, this is NOT the same position as (80.0, 40.0) on the original canvas.
            ctx.transform(Affine::rotate(std::f64::consts::FRAC_PI_4));
            layout.draw(ctx, (80.0, 40.0));
        });
        // When we exit with_save, the original context's rotation is restored

        // This is the builder-style way of drawing text.
        let text = ctx.text();
        let layout = text
            .new_text_layout(data.clone())
            .font(FontFamily::SERIF, 24.0)
            .text_color(Color::rgb8(128, 0, 0))
            .build()
            .unwrap();
        ctx.draw_text(&layout, (100.0, 25.0));

        // Let's burn some CPU to make a (partially transparent) image buffer
        let image_data = make_image_data(256, 256);
        let image = ctx
            .make_image(256, 256, &image_data, ImageFormat::RgbaSeparate)
            .unwrap();
        // The image is automatically scaled to fit the rect you pass to draw_image
        ctx.draw_image(&image, size.to_rect(), InterpolationMode::Bilinear);
    }
source

pub const fn with_size(self, size: f64) -> Self

Buider-style method to set the descriptor’s font size.

Examples found in repository?
examples/event_viewer.rs (line 341)
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351

pub fn main() {
    //describe the main window
    let main_window = WindowDesc::new(build_root_widget())
        .title("Event Viewer")
        .window_size((760.0, 680.0));

    //start the application
    AppLauncher::with_window(main_window)
        .log_to_console()
        .configure_env(|env, _| {
            env.set(theme::UI_FONT, FontDescriptor::default().with_size(12.0));
            env.set(theme::TEXT_COLOR, TEXT_COLOR);
            env.set(theme::WIDGET_PADDING_HORIZONTAL, 2.0);
            env.set(theme::WIDGET_PADDING_VERTICAL, 2.0);
        })
        .launch(AppState {
            text_input: String::new(),
            events: Arc::new(Vec::new()),
        })
        .expect("Failed to launch application");
}
More examples
Hide additional examples
examples/styled_text.rs (line 111)
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160

fn ui_builder() -> impl Widget<AppData> {
    let my_painter = Painter::new(|ctx, _, _| {
        let bounds = ctx.size().to_rect();
        if ctx.is_hot() {
            ctx.fill(bounds, &Color::rgba8(0, 0, 0, 128));
        }

        if ctx.is_active() {
            ctx.stroke(bounds, &Color::WHITE, 2.0);
        }
    });

    // This is Druid's default text style.
    // It's set by theme::LABEL_COLOR and theme::UI_FONT
    let label =
        Label::new(|data: &String, _env: &_| format!("Default: {data}")).lens(AppData::text);

    // The text_color, text_size, and font builder methods can override the
    // defaults provided by the theme by passing in a Key or a concrete value.
    //
    // In this example, text_color receives a Key from the theme, text_size
    // gets a custom key which we set with the env_scope wrapper, and the
    // default font key (theme::FONT_NAME) is overridden in the env_scope
    // wrapper. (Like text_color and text_size, the font can be set using the
    // with_font builder method, but overriding here makes it easy to fall back
    // to the default font)
    let styled_label = Label::new(|data: &AppData, _env: &_| format!("{data}"))
        .with_text_color(theme::PRIMARY_LIGHT)
        .with_font(MY_CUSTOM_FONT)
        .background(my_painter)
        .on_click(|_, data, _| {
            data.size *= 1.1;
        })
        .env_scope(|env: &mut druid::Env, data: &AppData| {
            let new_font = if data.mono {
                FontDescriptor::new(FontFamily::MONOSPACE)
            } else {
                FontDescriptor::new(FontFamily::SYSTEM_UI)
            }
            .with_size(data.size);
            env.set(MY_CUSTOM_FONT, new_font);
        });

    let labels = Scroll::new(
        Flex::column()
            .cross_axis_alignment(CrossAxisAlignment::Start)
            .with_child(label)
            .with_default_spacer()
            .with_child(styled_label),
    )
    .expand_height()
    .fix_width(COLUMN_WIDTH);

    let stepper = Stepper::new()
        .with_range(0.0, 100.0)
        .with_step(1.0)
        .with_wraparound(false)
        .lens(AppData::size);

    // TODO: Replace Parse usage with TextBox::with_formatter
    #[allow(deprecated)]
    let stepper_textbox = LensWrap::new(
        Parse::new(TextBox::new()),
        AppData::size.map(|x| Some(*x), |x, y| *x = y.unwrap_or(24.0)),
    );

    let mono_checkbox = Checkbox::new("Monospace").lens(AppData::mono);
    let stepper_row = Flex::row()
        .with_child(stepper_textbox)
        .with_child(stepper)
        .with_default_spacer()
        .with_child(mono_checkbox);

    let input = TextBox::multiline()
        .with_placeholder("Your sample text here :)")
        .fix_width(COLUMN_WIDTH)
        .fix_height(140.0)
        .lens(AppData::text);

    Flex::column()
        .main_axis_alignment(MainAxisAlignment::Center)
        .with_default_spacer()
        .with_flex_child(labels, 1.0)
        .with_default_spacer()
        .with_child(input)
        .with_default_spacer()
        .with_child(stepper_row)
        .with_default_spacer()
}
examples/custom_widget.rs (line 119)
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153

    fn paint(&mut self, ctx: &mut PaintCtx, data: &String, env: &Env) {
        // Clear the whole widget with the color of your choice
        // (ctx.size() returns the size of the layout rect we're painting in)
        // Note: ctx also has a `clear` method, but that clears the whole context,
        // and we only want to clear this widget's area.
        let size = ctx.size();
        let rect = size.to_rect();
        ctx.fill(rect, &Color::WHITE);

        // We can paint with a Z index, this indicates that this code will be run
        // after the rest of the painting. Painting with z-index is done in order,
        // so first everything with z-index 1 is painted and then with z-index 2 etc.
        // As you can see this(red) curve is drawn on top of the green curve
        ctx.paint_with_z_index(1, move |ctx| {
            let mut path = BezPath::new();
            path.move_to((0.0, size.height));
            path.quad_to((40.0, 50.0), (size.width, 0.0));
            // Create a color
            let stroke_color = Color::rgb8(128, 0, 0);
            // Stroke the path with thickness 1.0
            ctx.stroke(path, &stroke_color, 5.0);
        });

        // Create an arbitrary bezier path
        let mut path = BezPath::new();
        path.move_to(Point::ORIGIN);
        path.quad_to((40.0, 50.0), (size.width, size.height));
        // Create a color
        let stroke_color = Color::rgb8(0, 128, 0);
        // Stroke the path with thickness 5.0
        ctx.stroke(path, &stroke_color, 5.0);

        // Rectangles: the path for practical people
        let rect = Rect::from_origin_size((10.0, 10.0), (100.0, 100.0));
        // Note the Color:rgba8 which includes an alpha channel (7F in this case)
        let fill_color = Color::rgba8(0x00, 0x00, 0x00, 0x7F);
        ctx.fill(rect, &fill_color);

        // Text is easy; in real use TextLayout should either be stored in the
        // widget and reused, or a label child widget to manage it all.
        // This is one way of doing it, you can also use a builder-style way.
        let mut layout = TextLayout::<String>::from_text(data);
        layout.set_font(FontDescriptor::new(FontFamily::SERIF).with_size(24.0));
        layout.set_text_color(fill_color);
        layout.rebuild_if_needed(ctx.text(), env);

        // Let's rotate our text slightly. First we save our current (default) context:
        ctx.with_save(|ctx| {
            // Now we can rotate the context (or set a clip path, for instance):
            // This makes it so that anything drawn after this (in the closure) is
            // transformed.
            // The transformation is in radians, but be aware it transforms the canvas,
            // not just the part you are drawing. So we draw at (80.0, 40.0) on the rotated
            // canvas, this is NOT the same position as (80.0, 40.0) on the original canvas.
            ctx.transform(Affine::rotate(std::f64::consts::FRAC_PI_4));
            layout.draw(ctx, (80.0, 40.0));
        });
        // When we exit with_save, the original context's rotation is restored

        // This is the builder-style way of drawing text.
        let text = ctx.text();
        let layout = text
            .new_text_layout(data.clone())
            .font(FontFamily::SERIF, 24.0)
            .text_color(Color::rgb8(128, 0, 0))
            .build()
            .unwrap();
        ctx.draw_text(&layout, (100.0, 25.0));

        // Let's burn some CPU to make a (partially transparent) image buffer
        let image_data = make_image_data(256, 256);
        let image = ctx
            .make_image(256, 256, &image_data, ImageFormat::RgbaSeparate)
            .unwrap();
        // The image is automatically scaled to fit the rect you pass to draw_image
        ctx.draw_image(&image, size.to_rect(), InterpolationMode::Bilinear);
    }
source

pub const fn with_weight(self, weight: FontWeight) -> Self

Buider-style method to set the descriptor’s FontWeight.

source

pub const fn with_style(self, style: FontStyle) -> Self

Buider-style method to set the descriptor’s FontStyle.

Trait Implementations§

source§

impl Clone for FontDescriptor

source§

fn clone(&self) -> FontDescriptor

Returns a copy of the value. Read more
1.0.0 · source§

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

Performs copy-assignment from source. Read more
source§

impl Data for FontDescriptor

source§

fn same(&self, other: &Self) -> bool

Determine whether two values are the same. Read more
source§

impl Debug for FontDescriptor

source§

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter. Read more
source§

impl Default for FontDescriptor

source§

fn default() -> Self

Returns the “default value” for a type. Read more
source§

impl From<FontDescriptor> for Value

source§

fn from(val: FontDescriptor) -> Value

Converts to this type from the input type.
source§

impl PartialEq<FontDescriptor> for FontDescriptor

source§

fn eq(&self, other: &FontDescriptor) -> bool

This method tests for self and other values to be equal, and is used by ==.
1.0.0 · source§

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.
source§

impl ValueType for FontDescriptor

source§

fn try_from_value(value: &Value) -> Result<Self, ValueTypeError>

Attempt to convert the generic Value into this type.
source§

impl StructuralPartialEq for FontDescriptor

Auto Trait Implementations§

Blanket Implementations§

source§

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

source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
source§

impl<T> AnyEq for Twhere T: Any + PartialEq<T>,

source§

fn equals(&self, other: &(dyn Any + 'static)) -> bool

source§

fn as_any(&self) -> &(dyn Any + 'static)

source§

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

const: unstable · source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

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

const: unstable · source§

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

Mutably borrows from an owned value. Read more
source§

impl<T> From<T> for T

const: unstable · source§

fn from(t: T) -> T

Returns the argument unchanged.

source§

impl<T> Instrument for T

source§

fn instrument(self, span: Span) -> Instrumented<Self>

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
source§

fn in_current_span(self) -> Instrumented<Self>

Instruments this type with the current Span, returning an Instrumented wrapper. Read more
source§

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

const: unstable · source§

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

§

impl<T> RoundFrom<T> for T

§

fn round_from(x: T) -> T

Performs the conversion.
§

impl<T, U> RoundInto<U> for Twhere U: RoundFrom<T>,

§

fn round_into(self) -> U

Performs the conversion.
source§

impl<T> Same<T> for T

§

type Output = T

Should always be Self
source§

impl<T> ToOwned for Twhere T: Clone,

§

type Owned = T

The resulting type after obtaining ownership.
source§

fn to_owned(&self) -> T

Creates owned data from borrowed data, usually by cloning. Read more
source§

fn clone_into(&self, target: &mut T)

Uses borrowed data to replace owned data, usually by cloning. Read more
source§

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

§

type Error = Infallible

The type returned in the event of a conversion error.
const: unstable · source§

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
source§

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

§

type Error = <U as TryFrom<T>>::Error

The type returned in the event of a conversion error.
const: unstable · source§

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.
source§

impl<T> WithSubscriber for T

source§

fn with_subscriber<S>(self, subscriber: S) -> WithDispatch<Self>where S: Into<Dispatch>,

Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
source§

fn with_current_subscriber(self) -> WithDispatch<Self>

Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more