r3bl_tui 0.1.2

/*
 *   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 bitflags::bitflags;
use crossterm::event::*;
use serde::{Deserialize, Serialize};

bitflags! {
  #[derive(Serialize, Deserialize)]
  pub struct ModifierKeysMask: u8 {
    const SHIFT = 0b0000_0001;
    const CTRL  = 0b0000_0010;
    const ALT   = 0b0000_0100;
  }
}

pub fn convert_key_modifiers(modifiers: &KeyModifiers) -> Option<ModifierKeysMask> {
  // Start w/ empty my_modifiers.
  let my_modifiers: ModifierKeysMask = (*modifiers).into();
  if modifiers.is_empty() {
    None
  } else {
    Some(my_modifiers)
  }
}

impl From<KeyModifiers> for ModifierKeysMask {
  /// Difference in meaning between `intersects` and `contains`:
  /// - `intersects` -> means that the given bit shows up in your variable, but it might contain other
  ///   bits.
  /// - `contains` -> means that your variable ONLY contains these bits.
  fn from(other: KeyModifiers) -> Self {
    // Start w/ empty my_modifiers.
    let mut my_modifiers: ModifierKeysMask = ModifierKeysMask::empty(); // 0b0000_0000

    // Try and set any bitflags from key_event.
    if other.intersects(KeyModifiers::SHIFT) {
      my_modifiers.insert(ModifierKeysMask::SHIFT) // my_modifiers = 0b0000_0001;
    }
    if other.intersects(KeyModifiers::CONTROL) {
      my_modifiers.insert(ModifierKeysMask::CTRL) // my_modifiers = 0b0000_0010;
    }
    if other.intersects(KeyModifiers::ALT) {
      my_modifiers.insert(ModifierKeysMask::ALT) // my_modifiers = 0b0000_0100;
    }

    my_modifiers
  }
}