use crate::{App, Bounds, Context, Entity, InputHandler, Pixels, UTF16Selection, Window};use std::ops::Range; /// Implement this trait to allow views to handle textual input when implementing an editor, field, etc.////// Once your view implements this trait, you can use it to construct an [`ElementInputHandler<V>`]./// This input handler can then be assigned during paint by calling [`Window::handle_input`].////// See [`InputHandler`] for details on how to implement each method.pub trait EntityInputHandler: 'static + Sized {    /// See [`InputHandler::text_for_range`] for details    fn text_for_range(        &mut self,        range: Range<usize>,        adjusted_range: &mut Option<Range<usize>>,        window: &mut Window,        cx: &mut Context<Self>,    ) -> Option<String>;     /// See [`InputHandler::selected_text_range`] for details    fn selected_text_range(        &mut self,        ignore_disabled_input: bool,        window: &mut Window,        cx: &mut Context<Self>,    ) -> Option<UTF16Selection>;     /// See [`InputHandler::marked_text_range`] for details    fn marked_text_range(        &self,        window: &mut Window,        cx: &mut Context<Self>,    ) -> Option<Range<usize>>;     /// See [`InputHandler::unmark_text`] for details    fn unmark_text(&mut self, window: &mut Window, cx: &mut Context<Self>);     /// See [`InputHandler::replace_text_in_range`] for details    fn replace_text_in_range(        &mut self,        range: Option<Range<usize>>,        text: &str,        window: &mut Window,        cx: &mut Context<Self>,    );     /// See [`InputHandler::replace_and_mark_text_in_range`] for details    fn replace_and_mark_text_in_range(        &mut self,        range: Option<Range<usize>>,        new_text: &str,        new_selected_range: Option<Range<usize>>,        window: &mut Window,        cx: &mut Context<Self>,    );     /// See [`InputHandler::bounds_for_range`] for details    fn bounds_for_range(        &mut self,        range_utf16: Range<usize>,        element_bounds: Bounds<Pixels>,        window: &mut Window,        cx: &mut Context<Self>,    ) -> Option<Bounds<Pixels>>;     /// See [`InputHandler::character_index_for_point`] for details    fn character_index_for_point(        &mut self,        point: crate::Point<Pixels>,        window: &mut Window,        cx: &mut Context<Self>,    ) -> Option<usize>;     /// See [`InputHandler::set_selected_text_range`] for details    fn set_selected_text_range(        &mut self,        _range_utf16: Range<usize>,        _window: &mut Window,        _cx: &mut Context<Self>,    ) {    }     /// See [`InputHandler::text_length_utf16`] for details    fn text_length_utf16(        &mut self,        _window: &mut Window,        _cx: &mut Context<Self>,    ) -> Option<usize> {        None    }     /// See [`InputHandler::accepts_text_input`] for details    fn accepts_text_input(&self, _window: &mut Window, _cx: &mut Context<Self>) -> bool {        true    }} /// The canonical implementation of [`crate::PlatformInputHandler`]. Call [`Window::handle_input`]/// with an instance during your element's paint.pub struct ElementInputHandler<V> {    view: Entity<V>,    element_bounds: Bounds<Pixels>,} impl<V: 'static> ElementInputHandler<V> {    /// Used in [`Element::paint`][element_paint] with the element's bounds, a `Window`, and a `App` context.    ///    /// [element_paint]: crate::Element::paint    pub fn new(element_bounds: Bounds<Pixels>, view: Entity<V>) -> Self {        ElementInputHandler {            view,            element_bounds,        }    }} impl<V: EntityInputHandler> InputHandler for ElementInputHandler<V> {    fn selected_text_range(        &mut self,        ignore_disabled_input: bool,        window: &mut Window,        cx: &mut App,    ) -> Option<UTF16Selection> {        self.view.update(cx, |view, cx| {            view.selected_text_range(ignore_disabled_input, window, cx)        })    }     fn marked_text_range(&mut self, window: &mut Window, cx: &mut App) -> Option<Range<usize>> {        self.view            .update(cx, |view, cx| view.marked_text_range(window, cx))    }     fn text_for_range(        &mut self,        range_utf16: Range<usize>,        adjusted_range: &mut Option<Range<usize>>,        window: &mut Window,        cx: &mut App,    ) -> Option<String> {        self.view.update(cx, |view, cx| {            view.text_for_range(range_utf16, adjusted_range, window, cx)        })    }     fn replace_text_in_range(        &mut self,        replacement_range: Option<Range<usize>>,        text: &str,        window: &mut Window,        cx: &mut App,    ) {        self.view.update(cx, |view, cx| {            view.replace_text_in_range(replacement_range, text, window, cx)        });    }     fn replace_and_mark_text_in_range(        &mut self,        range_utf16: Option<Range<usize>>,        new_text: &str,        new_selected_range: Option<Range<usize>>,        window: &mut Window,        cx: &mut App,    ) {        self.view.update(cx, |view, cx| {            view.replace_and_mark_text_in_range(                range_utf16,                new_text,                new_selected_range,                window,                cx,            )        });    }     fn unmark_text(&mut self, window: &mut Window, cx: &mut App) {        self.view            .update(cx, |view, cx| view.unmark_text(window, cx));    }     fn bounds_for_range(        &mut self,        range_utf16: Range<usize>,        window: &mut Window,        cx: &mut App,    ) -> Option<Bounds<Pixels>> {        self.view.update(cx, |view, cx| {            view.bounds_for_range(range_utf16, self.element_bounds, window, cx)        })    }     fn character_index_for_point(        &mut self,        point: crate::Point<Pixels>,        window: &mut Window,        cx: &mut App,    ) -> Option<usize> {        self.view.update(cx, |view, cx| {            view.character_index_for_point(point, window, cx)        })    }     fn set_selected_text_range(        &mut self,        range_utf16: Range<usize>,        window: &mut Window,        cx: &mut App,    ) {        self.view.update(cx, |view, cx| {            view.set_selected_text_range(range_utf16, window, cx)        })    }     fn element_bounds(&mut self, _window: &mut Window, _cx: &mut App) -> Option<Bounds<Pixels>> {        Some(self.element_bounds)    }     fn text_length_utf16(&mut self, window: &mut Window, cx: &mut App) -> Option<usize> {        self.view            .update(cx, |view, cx| view.text_length_utf16(window, cx))    }     fn accepts_text_input(&mut self, window: &mut Window, cx: &mut App) -> bool {        self.view            .update(cx, |view, cx| view.accepts_text_input(window, cx))    }     fn prefers_ime_for_printable_keys(&mut self, window: &mut Window, cx: &mut App) -> bool {        self.view            .update(cx, |view, cx| view.accepts_text_input(window, cx))    }}