I have an iced program that draws a line graph onto a canvas. It works. I want to be able to add button like functionality to the canvas so that when I click on some text I can redraw the graph with a different range of dates (the x axis values). I have added an update function to my canvas program and am able to capture mouse click events on the canvas and retrieve the x and y coordinates. With a little more code I think I can make it work. But in my testing mode I cannot figure out how to return a message to the main programs update function. The error message I get with the code below when attempting to return "Message::Welcome" is that Welcome is not known in the current scope. But my Message enum has a Welcome item and I have added the file with Message enum to this file using "use crate::utils::...::Message" but it is listed as in unused import. Any assistance will be appreciated.
#[derive(Debug, Clone)]
pub enum Message {
// Increment,
DisplayGraph,
Welcome,
UpdateStartDates(Vec<String>),
Exit,
}
pub struct LineGraph {
pub points: Vec<Point>,
pub x_values: Vec<String>,
pub y_values: Vec<String>,
pub index_values: Vec<IndexDateClose>,
}
impl<Message> canvas::Program<Message> for LineGraph {
type State = ();
fn draw(
&self,
_state: &(),
renderer: &Renderer,
_theme: &Theme,
bounds: iced::Rectangle,
_cursor: iced::advanced::mouse::Cursor,
) -> Vec<canvas::Geometry<Renderer>> {
let mut frame = canvas::Frame::new(renderer, bounds.size());
draw_heading(&mut frame);
draw_axis(&mut frame);
draw_grid(&mut frame);
draw_x_axis_ticks(&mut frame);
draw_x_axis_labels(&mut frame, &self.x_values);
draw_y_axis_ticks(&mut frame);
draw_y_axis_labels(&mut frame, &self.y_values);
draw_data_points(&mut frame, &self.points);
draw_overlay(&mut frame, &self.points, &self.index_values);
vec![frame.into_geometry()]
} // end of function draw
fn update(
&self,
_state: &mut Self::State,
event: &iced::Event,
bounds: Rectangle,
cursor: Cursor,
) -> Option<iced::widget::Action<Message>> {
match event {
canvas::Event::Mouse(mouse::Event::ButtonPressed(mouse::Button::Left)) => {
if let Some(mouse_position) = cursor.position_in(bounds) {
println!("--------------------------");
println!("clicked on canvas");
println!("point x = {}", mouse_position.x);
println!("point y = {}", mouse_position.y);
// None
Some(iced::widget::Action::publish(Message::Welcome))
} else {
None
}// end if let some
}
_ => None,
}
} // end update function
}