Struct DrawHandler

Source

pub struct DrawHandler { /* private fields */ }

Expand description

Manager for drawing operations.

Implementations§

Source §

impl DrawHandler

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pub fn new() -> Self

Create a new DrawHandler.

Examples found in repository ?

relm4/examples/drawing.rs (line 123)

114    fn init(
115        _: Self::Init,
116        root: Self::Root,
117        sender: ComponentSender<Self>,
118    ) -> ComponentParts<Self> {
119        let model = App {
120            width: 100.0,
121            height: 100.0,
122            points: Vec::new(),
123            handler: DrawHandler::new(),
124        };
125
126        let area = model.handler.drawing_area();
127        let widgets = view_output!();
128
129        sender.command(|out, shutdown| {
130            shutdown
131                .register(async move {
132                    loop {
133                        tokio::time::sleep(Duration::from_millis(20)).await;
134                        out.send(UpdatePointsMsg).unwrap();
135                    }
136                })
137                .drop_on_shutdown()
138        });
139
140        ComponentParts { model, widgets }
141    }

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pub fn new_with_drawing_area(drawing_area: DrawingArea) -> Self

Create a new DrawHandler with an existing gtk::DrawingArea.

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pub fn get_context(&mut self) -> DrawContext

Get the drawing context to draw on a gtk::DrawingArea. If the size of the gtk::DrawingArea changed, the contents of the surface will be replaced by a new, empty surface.

Examples found in repository ?

relm4/examples/drawing.rs (line 70)

69    fn update(&mut self, msg: Msg, _sender: ComponentSender<Self>, _root: &Self::Root) {
70        let cx = self.handler.get_context();
71
72        match msg {
73            Msg::AddPoint((x, y)) => {
74                self.points.push(Point::new(x, y));
75            }
76            Msg::Resize => {
77                self.width = self.handler.width() as f64;
78                self.height = self.handler.height() as f64;
79            }
80            Msg::Reset => {
81                cx.set_operator(Operator::Clear);
82                cx.set_source_rgba(0.0, 0.0, 0.0, 0.0);
83                cx.paint().expect("Couldn't fill context");
84            }
85        }
86
87        draw(&cx, &self.points);
88    }
89
90    fn update_cmd(&mut self, _: UpdatePointsMsg, _: ComponentSender<Self>, _root: &Self::Root) {
91        for point in &mut self.points {
92            let Point { x, y, .. } = point;
93            if *x < 0.0 {
94                point.xs = point.xs.abs();
95            } else if *x > self.width {
96                point.xs = -point.xs.abs();
97            }
98            *x = x.clamp(0.0, self.width);
99            *x += point.xs;
100
101            if *y < 0.0 {
102                point.ys = point.ys.abs();
103            } else if *y > self.height {
104                point.ys = -point.ys.abs();
105            }
106            *y = y.clamp(0.0, self.height);
107            *y += point.ys;
108        }
109
110        let cx = self.handler.get_context();
111        draw(&cx, &self.points);
112    }

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pub fn size(&self) -> (i32, i32)

Get the width and height of the DrawHandler in pixels.

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pub fn height(&self) -> i32

Get the height of the DrawHandler in pixels.

Examples found in repository ?

relm4/examples/drawing.rs (line 78)

69    fn update(&mut self, msg: Msg, _sender: ComponentSender<Self>, _root: &Self::Root) {
70        let cx = self.handler.get_context();
71
72        match msg {
73            Msg::AddPoint((x, y)) => {
74                self.points.push(Point::new(x, y));
75            }
76            Msg::Resize => {
77                self.width = self.handler.width() as f64;
78                self.height = self.handler.height() as f64;
79            }
80            Msg::Reset => {
81                cx.set_operator(Operator::Clear);
82                cx.set_source_rgba(0.0, 0.0, 0.0, 0.0);
83                cx.paint().expect("Couldn't fill context");
84            }
85        }
86
87        draw(&cx, &self.points);
88    }

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pub fn width(&self) -> i32

Get the width of the DrawHandler in pixels.

Examples found in repository ?

relm4/examples/drawing.rs (line 77)

69    fn update(&mut self, msg: Msg, _sender: ComponentSender<Self>, _root: &Self::Root) {
70        let cx = self.handler.get_context();
71
72        match msg {
73            Msg::AddPoint((x, y)) => {
74                self.points.push(Point::new(x, y));
75            }
76            Msg::Resize => {
77                self.width = self.handler.width() as f64;
78                self.height = self.handler.height() as f64;
79            }
80            Msg::Reset => {
81                cx.set_operator(Operator::Clear);
82                cx.set_source_rgba(0.0, 0.0, 0.0, 0.0);
83                cx.paint().expect("Couldn't fill context");
84            }
85        }
86
87        draw(&cx, &self.points);
88    }

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pub fn surface_height(&self) -> i32

Get the height of the inner ImageSurface.

NOTE: Depending on the monitor scaling this is not necessarily the height in pixels.

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pub fn surface_width(&self) -> i32

Get the width of the inner ImageSurface.

NOTE: Depending on the monitor scaling this is not necessarily the width in pixels.

Source

pub fn drawing_area(&self) -> &DrawingArea

Get the gtk::DrawingArea of the DrawHandler.

Examples found in repository ?

relm4/examples/drawing.rs (line 126)

114    fn init(
115        _: Self::Init,
116        root: Self::Root,
117        sender: ComponentSender<Self>,
118    ) -> ComponentParts<Self> {
119        let model = App {
120            width: 100.0,
121            height: 100.0,
122            points: Vec::new(),
123            handler: DrawHandler::new(),
124        };
125
126        let area = model.handler.drawing_area();
127        let widgets = view_output!();
128
129        sender.command(|out, shutdown| {
130            shutdown
131                .register(async move {
132                    loop {
133                        tokio::time::sleep(Duration::from_millis(20)).await;
134                        out.send(UpdatePointsMsg).unwrap();
135                    }
136                })
137                .drop_on_shutdown()
138        });
139
140        ComponentParts { model, widgets }
141    }