iced_core 0.14.0

//! Operate on widgets that have text input.
use crate::Rectangle;
use crate::widget::Id;
use crate::widget::operation::Operation;

/// The internal state of a widget that has text input.
pub trait TextInput {
    /// Returns the current _visible_ text of the text input
    ///
    /// Normally, this is either its value or its placeholder.
    fn text(&self) -> &str;

    /// Moves the cursor of the text input to the front of the input text.
    fn move_cursor_to_front(&mut self);

    /// Moves the cursor of the text input to the end of the input text.
    fn move_cursor_to_end(&mut self);

    /// Moves the cursor of the text input to an arbitrary location.
    fn move_cursor_to(&mut self, position: usize);

    /// Selects all the content of the text input.
    fn select_all(&mut self);
    /// Selects the given content range of the text input.
    fn select_range(&mut self, start: usize, end: usize);
}

/// Produces an [`Operation`] that moves the cursor of the widget with the given [`Id`] to the
/// front.
pub fn move_cursor_to_front<T>(target: Id) -> impl Operation<T> {
    struct MoveCursor {
        target: Id,
    }

    impl<T> Operation<T> for MoveCursor {
        fn text_input(
            &mut self,
            id: Option<&Id>,
            _bounds: Rectangle,
            state: &mut dyn TextInput,
        ) {
            match id {
                Some(id) if id == &self.target => {
                    state.move_cursor_to_front();
                }
                _ => {}
            }
        }

        fn traverse(&mut self, operate: &mut dyn FnMut(&mut dyn Operation<T>)) {
            operate(self);
        }
    }

    MoveCursor { target }
}

/// Produces an [`Operation`] that moves the cursor of the widget with the given [`Id`] to the
/// end.
pub fn move_cursor_to_end<T>(target: Id) -> impl Operation<T> {
    struct MoveCursor {
        target: Id,
    }

    impl<T> Operation<T> for MoveCursor {
        fn text_input(
            &mut self,
            id: Option<&Id>,
            _bounds: Rectangle,
            state: &mut dyn TextInput,
        ) {
            match id {
                Some(id) if id == &self.target => {
                    state.move_cursor_to_end();
                }
                _ => {}
            }
        }

        fn traverse(&mut self, operate: &mut dyn FnMut(&mut dyn Operation<T>)) {
            operate(self);
        }
    }

    MoveCursor { target }
}

/// Produces an [`Operation`] that moves the cursor of the widget with the given [`Id`] to the
/// provided position.
pub fn move_cursor_to<T>(target: Id, position: usize) -> impl Operation<T> {
    struct MoveCursor {
        target: Id,
        position: usize,
    }

    impl<T> Operation<T> for MoveCursor {
        fn text_input(
            &mut self,
            id: Option<&Id>,
            _bounds: Rectangle,
            state: &mut dyn TextInput,
        ) {
            match id {
                Some(id) if id == &self.target => {
                    state.move_cursor_to(self.position);
                }
                _ => {}
            }
        }

        fn traverse(&mut self, operate: &mut dyn FnMut(&mut dyn Operation<T>)) {
            operate(self);
        }
    }

    MoveCursor { target, position }
}

/// Produces an [`Operation`] that selects all the content of the widget with the given [`Id`].
pub fn select_all<T>(target: Id) -> impl Operation<T> {
    struct MoveCursor {
        target: Id,
    }

    impl<T> Operation<T> for MoveCursor {
        fn text_input(
            &mut self,
            id: Option<&Id>,
            _bounds: Rectangle,
            state: &mut dyn TextInput,
        ) {
            match id {
                Some(id) if id == &self.target => {
                    state.select_all();
                }
                _ => {}
            }
        }

        fn traverse(&mut self, operate: &mut dyn FnMut(&mut dyn Operation<T>)) {
            operate(self);
        }
    }

    MoveCursor { target }
}

/// Produces an [`Operation`] that selects the given content range of the widget with the given [`Id`].
pub fn select_range<T>(
    target: Id,
    start: usize,
    end: usize,
) -> impl Operation<T> {
    struct SelectRange {
        target: Id,
        start: usize,
        end: usize,
    }

    impl<T> Operation<T> for SelectRange {
        fn text_input(
            &mut self,
            id: Option<&Id>,
            _bounds: Rectangle,
            state: &mut dyn TextInput,
        ) {
            match id {
                Some(id) if id == &self.target => {
                    state.select_range(self.start, self.end);
                }
                _ => {}
            }
        }

        fn traverse(&mut self, operate: &mut dyn FnMut(&mut dyn Operation<T>)) {
            operate(self);
        }
    }

    SelectRange { target, start, end }
}