libs/input/rust/input.rs

/*
 * Copyright 2023 The Android Open Source Project
 *
 * 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.
 */

//! Common definitions of the Android Input Framework in rust.

use bitflags::bitflags;
use std::fmt;

/// The InputDevice ID.
#[derive(Debug, Copy, Clone, Eq, PartialEq, Ord, PartialOrd, Hash)]
pub struct DeviceId(pub i32);

/// A rust enum representation of a MotionEvent action.
#[repr(u32)]
pub enum MotionAction {
    /// ACTION_DOWN
    Down = input_bindgen::AMOTION_EVENT_ACTION_DOWN,
    /// ACTION_UP
    Up = input_bindgen::AMOTION_EVENT_ACTION_UP,
    /// ACTION_MOVE
    Move = input_bindgen::AMOTION_EVENT_ACTION_MOVE,
    /// ACTION_CANCEL
    Cancel = input_bindgen::AMOTION_EVENT_ACTION_CANCEL,
    /// ACTION_OUTSIDE
    Outside = input_bindgen::AMOTION_EVENT_ACTION_OUTSIDE,
    /// ACTION_POINTER_DOWN
    PointerDown {
        /// The index of the affected pointer.
        action_index: usize,
    } = input_bindgen::AMOTION_EVENT_ACTION_POINTER_DOWN,
    /// ACTION_POINTER_UP
    PointerUp {
        /// The index of the affected pointer.
        action_index: usize,
    } = input_bindgen::AMOTION_EVENT_ACTION_POINTER_UP,
    /// ACTION_HOVER_ENTER
    HoverEnter = input_bindgen::AMOTION_EVENT_ACTION_HOVER_ENTER,
    /// ACTION_HOVER_MOVE
    HoverMove = input_bindgen::AMOTION_EVENT_ACTION_HOVER_MOVE,
    /// ACTION_HOVER_EXIT
    HoverExit = input_bindgen::AMOTION_EVENT_ACTION_HOVER_EXIT,
    /// ACTION_SCROLL
    Scroll = input_bindgen::AMOTION_EVENT_ACTION_SCROLL,
    /// ACTION_BUTTON_PRESS
    ButtonPress = input_bindgen::AMOTION_EVENT_ACTION_BUTTON_PRESS,
    /// ACTION_BUTTON_RELEASE
    ButtonRelease = input_bindgen::AMOTION_EVENT_ACTION_BUTTON_RELEASE,
}

impl fmt::Display for MotionAction {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        match self {
            MotionAction::Down => write!(f, "DOWN"),
            MotionAction::Up => write!(f, "UP"),
            MotionAction::Move => write!(f, "MOVE"),
            MotionAction::Cancel => write!(f, "CANCEL"),
            MotionAction::Outside => write!(f, "OUTSIDE"),
            MotionAction::PointerDown { action_index } => {
                write!(f, "POINTER_DOWN({})", action_index)
            }
            MotionAction::PointerUp { action_index } => write!(f, "POINTER_UP({})", action_index),
            MotionAction::HoverMove => write!(f, "HOVER_MOVE"),
            MotionAction::Scroll => write!(f, "SCROLL"),
            MotionAction::HoverEnter => write!(f, "HOVER_ENTER"),
            MotionAction::HoverExit => write!(f, "HOVER_EXIT"),
            MotionAction::ButtonPress => write!(f, "BUTTON_PRESS"),
            MotionAction::ButtonRelease => write!(f, "BUTTON_RELEASE"),
        }
    }
}

impl From<u32> for MotionAction {
    fn from(action: u32) -> Self {
        let (action_masked, action_index) = MotionAction::breakdown_action(action);
        match action_masked {
            input_bindgen::AMOTION_EVENT_ACTION_DOWN => MotionAction::Down,
            input_bindgen::AMOTION_EVENT_ACTION_UP => MotionAction::Up,
            input_bindgen::AMOTION_EVENT_ACTION_MOVE => MotionAction::Move,
            input_bindgen::AMOTION_EVENT_ACTION_CANCEL => MotionAction::Cancel,
            input_bindgen::AMOTION_EVENT_ACTION_OUTSIDE => MotionAction::Outside,
            input_bindgen::AMOTION_EVENT_ACTION_POINTER_DOWN => {
                MotionAction::PointerDown { action_index }
            }
            input_bindgen::AMOTION_EVENT_ACTION_POINTER_UP => {
                MotionAction::PointerUp { action_index }
            }
            input_bindgen::AMOTION_EVENT_ACTION_HOVER_ENTER => MotionAction::HoverEnter,
            input_bindgen::AMOTION_EVENT_ACTION_HOVER_MOVE => MotionAction::HoverMove,
            input_bindgen::AMOTION_EVENT_ACTION_HOVER_EXIT => MotionAction::HoverExit,
            input_bindgen::AMOTION_EVENT_ACTION_SCROLL => MotionAction::Scroll,
            input_bindgen::AMOTION_EVENT_ACTION_BUTTON_PRESS => MotionAction::ButtonPress,
            input_bindgen::AMOTION_EVENT_ACTION_BUTTON_RELEASE => MotionAction::ButtonRelease,
            _ => panic!("Unknown action: {}", action),
        }
    }
}

impl MotionAction {
    fn breakdown_action(action: u32) -> (u32, usize) {
        let action_masked = action & input_bindgen::AMOTION_EVENT_ACTION_MASK;
        let index = (action & input_bindgen::AMOTION_EVENT_ACTION_POINTER_INDEX_MASK)
            >> input_bindgen::AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT;
        (action_masked, index.try_into().unwrap())
    }
}

bitflags! {
    /// MotionEvent flags.
    pub struct MotionFlags: i32 {
        /// FLAG_CANCELED
        const CANCELED = input_bindgen::AMOTION_EVENT_FLAG_CANCELED;
    }
}