r3bl_tui 0.3.6

/*
 *   Copyright (c) 2022 R3BL LLC
 *   All rights reserved.
 *
 *   Licensed under the Apache License, Version 2.0 (the "License");
 *   you may not use this file except in compliance with the License.
 *   You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 *   Unless required by applicable law or agreed to in writing, software
 *   distributed under the License is distributed on an "AS IS" BASIS,
 *   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *   See the License for the specific language governing permissions and
 *   limitations under the License.
 */

use serde::{Deserialize, Serialize};

use crate::*;

/// By providing a conversion from [InputEvent] to [DialogEvent] it becomes easier to write event
/// handlers that consume [InputEvent] and then process events in [DialogComponent] and
/// [DialogEngine].
#[derive(Debug, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub enum DialogEvent {
    ActivateModal,
    EnterPressed,
    EscPressed,
    None,
}

mod dialog_event_impl {
    use super::*;

    impl DialogEvent {
        /// The `modal_keypress` is used to determine whether the [InputEvent] should be converted to
        /// [DialogEvent::ActivateModal].
        pub fn should_activate_modal(
            input_event: &InputEvent,
            modal_keypress: KeyPress,
        ) -> Self {
            if let InputEvent::Keyboard(keypress) = input_event {
                if keypress == &modal_keypress {
                    return Self::ActivateModal;
                }
            }
            Self::None
        }

        /// Tries to convert the given [InputEvent] into a [DialogEvent].
        /// - Enter and Esc are also matched against to return [DialogEvent::EnterPressed] and
        ///   [DialogEvent::EscPressed]
        /// - Otherwise, [Err] is returned.
        pub fn from(input_event: &InputEvent) -> Self {
            if let InputEvent::Keyboard(keypress) = input_event {
                match keypress {
                    // Compare to `Enter`.
                    KeyPress::Plain {
                        key: Key::SpecialKey(SpecialKey::Enter),
                    } => {
                        return Self::EnterPressed;
                    }

                    // Compare to `Esc`.
                    KeyPress::Plain {
                        key: Key::SpecialKey(SpecialKey::Esc),
                    } => {
                        return Self::EscPressed;
                    }

                    _ => {}
                }
            }

            Self::None
        }
    }
}

#[cfg(test)]
mod test_dialog_event {
    use r3bl_rs_utils_core::*;

    use crate::*;

    #[test]
    fn dialog_event_handles_enter() {
        let input_event = InputEvent::Keyboard(keypress!(@special SpecialKey::Enter));
        let dialog_event = DialogEvent::from(&input_event);
        assert_eq2!(dialog_event, DialogEvent::EnterPressed);
    }

    #[test]
    fn dialog_event_handles_esc() {
        let input_event = InputEvent::Keyboard(keypress!(@special SpecialKey::Esc));
        let dialog_event = DialogEvent::from(&input_event);
        assert_eq2!(dialog_event, DialogEvent::EscPressed);
    }

    #[test]
    fn dialog_event_handles_modal_keypress() {
        let modal_keypress = keypress!(@char ModifierKeysMask::CTRL, 'l');
        let input_event = InputEvent::Keyboard(modal_keypress);
        let dialog_event =
            DialogEvent::should_activate_modal(&input_event, modal_keypress);
        assert_eq2!(dialog_event, DialogEvent::ActivateModal);
    }
}