ruffle/web/src/ui.rs

use super::JavascriptPlayer;
use ruffle_core::backend::ui::{Error, MouseCursor, UiBackend};
use ruffle_core::events::KeyCode;
use ruffle_web_common::JsResult;
use std::collections::HashSet;
use web_sys::{HtmlCanvasElement, KeyboardEvent};

#[derive(Debug)]
struct FullScreenError {
    jsval: String,
}

impl std::fmt::Display for FullScreenError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.write_str(&self.jsval)
    }
}

impl std::error::Error for FullScreenError {
    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
        None
    }
}

/// An implementation of `UiBackend` utilizing `web_sys` bindings to input APIs.
pub struct WebUiBackend {
    js_player: JavascriptPlayer,
    canvas: HtmlCanvasElement,
    keys_down: HashSet<KeyCode>,
    cursor_visible: bool,
    cursor: MouseCursor,
    last_key: KeyCode,
    last_char: Option<char>,
}

impl WebUiBackend {
    pub fn new(js_player: JavascriptPlayer, canvas: &HtmlCanvasElement) -> Self {
        Self {
            js_player,
            canvas: canvas.clone(),
            keys_down: HashSet::new(),
            cursor_visible: true,
            cursor: MouseCursor::Arrow,
            last_key: KeyCode::Unknown,
            last_char: None,
        }
    }

    /// Register a key press for a given code string.
    pub fn keydown(&mut self, event: &KeyboardEvent) {
        let key_code = web_to_ruffle_key_code(&event.code());
        self.last_key = key_code;
        self.keys_down.insert(key_code);
        self.last_char = web_key_to_codepoint(&event.key());
    }

    /// Register a key release for a given code string.
    pub fn keyup(&mut self, event: &KeyboardEvent) {
        let key_code = web_to_ruffle_key_code(&event.code());
        self.last_key = key_code;
        self.keys_down.remove(&key_code);
        self.last_char = web_key_to_codepoint(&event.key());
    }

    fn update_mouse_cursor(&self) {
        let cursor = if self.cursor_visible {
            match self.cursor {
                MouseCursor::Arrow => "auto",
                MouseCursor::Hand => "pointer",
                MouseCursor::IBeam => "text",
                MouseCursor::Grab => "grab",
            }
        } else {
            "none"
        };
        self.canvas
            .style()
            .set_property("cursor", cursor)
            .warn_on_error();
    }
}

impl UiBackend for WebUiBackend {
    fn is_key_down(&self, key: KeyCode) -> bool {
        self.keys_down.contains(&key)
    }

    fn last_key_code(&self) -> KeyCode {
        self.last_key
    }

    fn last_key_char(&self) -> Option<char> {
        self.last_char
    }

    fn mouse_visible(&self) -> bool {
        self.cursor_visible
    }

    fn set_mouse_visible(&mut self, visible: bool) {
        self.cursor_visible = visible;
        self.update_mouse_cursor();
    }

    fn set_mouse_cursor(&mut self, cursor: MouseCursor) {
        self.cursor = cursor;
        self.update_mouse_cursor();
    }

    fn set_clipboard_content(&mut self, _content: String) {
        log::warn!("set clipboard not implemented");
    }

    fn set_fullscreen(&mut self, is_full: bool) -> Result<(), Error> {
        match self.js_player.set_fullscreen(is_full) {
            Ok(_) => Ok(()),
            Err(jsval) => Err(Box::new(FullScreenError {
                jsval: jsval
                    .as_string()
                    .unwrap_or_else(|| "Failed to change full screen state".to_string()),
            })),
        }
    }

    fn display_unsupported_message(&self) {
        self.js_player.display_unsupported_message()
    }

    fn display_root_movie_download_failed_message(&self) {
        self.js_player.display_root_movie_download_failed_message()
    }

    fn message(&self, message: &str) {
        self.js_player.display_message(message);
    }
}

/// Convert a web `KeyboardEvent.code` value into a Ruffle `KeyCode`.
/// Return `KeyCode::Unknown` if there is no matching Flash key code.
fn web_to_ruffle_key_code(key_code: &str) -> KeyCode {
    match key_code {
        "Backspace" => KeyCode::Backspace,
        "Tab" => KeyCode::Tab,
        "Enter" => KeyCode::Return,
        "ShiftLeft" | "ShiftRight" => KeyCode::Shift,
        "ControlLeft" | "ControlRight" => KeyCode::Control,
        "AltLeft" | "AltRight" => KeyCode::Alt,
        "CapsLock" => KeyCode::CapsLock,
        "Escape" => KeyCode::Escape,
        "Space" => KeyCode::Space,
        "Digit0" => KeyCode::Key0,
        "Digit1" => KeyCode::Key1,
        "Digit2" => KeyCode::Key2,
        "Digit3" => KeyCode::Key3,
        "Digit4" => KeyCode::Key4,
        "Digit5" => KeyCode::Key5,
        "Digit6" => KeyCode::Key6,
        "Digit7" => KeyCode::Key7,
        "Digit8" => KeyCode::Key8,
        "Digit9" => KeyCode::Key9,
        "KeyA" => KeyCode::A,
        "KeyB" => KeyCode::B,
        "KeyC" => KeyCode::C,
        "KeyD" => KeyCode::D,
        "KeyE" => KeyCode::E,
        "KeyF" => KeyCode::F,
        "KeyG" => KeyCode::G,
        "KeyH" => KeyCode::H,
        "KeyI" => KeyCode::I,
        "KeyJ" => KeyCode::J,
        "KeyK" => KeyCode::K,
        "KeyL" => KeyCode::L,
        "KeyM" => KeyCode::M,
        "KeyN" => KeyCode::N,
        "KeyO" => KeyCode::O,
        "KeyP" => KeyCode::P,
        "KeyQ" => KeyCode::Q,
        "KeyR" => KeyCode::R,
        "KeyS" => KeyCode::S,
        "KeyT" => KeyCode::T,
        "KeyU" => KeyCode::U,
        "KeyV" => KeyCode::V,
        "KeyW" => KeyCode::W,
        "KeyX" => KeyCode::X,
        "KeyY" => KeyCode::Y,
        "KeyZ" => KeyCode::Z,
        "Semicolon" => KeyCode::Semicolon,
        "Equal" => KeyCode::Equals,
        "Comma" => KeyCode::Comma,
        "Minus" => KeyCode::Minus,
        "Period" => KeyCode::Period,
        "Slash" => KeyCode::Slash,
        "Backquote" => KeyCode::Grave,
        "BracketLeft" => KeyCode::LBracket,
        "Backslash" => KeyCode::Backslash,
        "BracketRight" => KeyCode::RBracket,
        "Quote" => KeyCode::Apostrophe,
        "Numpad0" => KeyCode::Numpad0,
        "Numpad1" => KeyCode::Numpad1,
        "Numpad2" => KeyCode::Numpad2,
        "Numpad3" => KeyCode::Numpad3,
        "Numpad4" => KeyCode::Numpad4,
        "Numpad5" => KeyCode::Numpad5,
        "Numpad6" => KeyCode::Numpad6,
        "Numpad7" => KeyCode::Numpad7,
        "Numpad8" => KeyCode::Numpad8,
        "Numpad9" => KeyCode::Numpad9,
        "NumpadMultiply" => KeyCode::Multiply,
        "NumpadAdd" => KeyCode::Plus,
        "NumpadSubtract" => KeyCode::NumpadMinus,
        "NumpadDecimal" => KeyCode::NumpadPeriod,
        "NumpadDivide" => KeyCode::NumpadSlash,
        "PageUp" => KeyCode::PgUp,
        "PageDown" => KeyCode::PgDown,
        "End" => KeyCode::End,
        "Home" => KeyCode::Home,
        "ArrowLeft" => KeyCode::Left,
        "ArrowUp" => KeyCode::Up,
        "ArrowRight" => KeyCode::Right,
        "ArrowDown" => KeyCode::Down,
        "Insert" => KeyCode::Insert,
        "Delete" => KeyCode::Delete,
        "Pause" => KeyCode::Pause,
        "ScrollLock" => KeyCode::ScrollLock,
        "F1" => KeyCode::F1,
        "F2" => KeyCode::F2,
        "F3" => KeyCode::F3,
        "F4" => KeyCode::F4,
        "F5" => KeyCode::F5,
        "F6" => KeyCode::F6,
        "F7" => KeyCode::F7,
        "F8" => KeyCode::F8,
        "F9" => KeyCode::F9,
        "F10" => KeyCode::F10,
        "F11" => KeyCode::F11,
        "F12" => KeyCode::F12,
        _ => KeyCode::Unknown,
    }
}

/// Convert a web `KeyboardEvent.key` value into a character codepoint.
/// Return `None` if they input was not a printable character.
fn web_key_to_codepoint(key: &str) -> Option<char> {
    // TODO: This is a very cheesy way to tell if a `KeyboardEvent.key` is a printable character.
    // Single character strings will be an actual printable char that we can use as text input.
    // All the other special values are multiple characters (e.g. "ArrowLeft").
    // It's probably better to explicitly match on all the variants.
    let mut chars = key.chars();
    let (c1, c2) = (chars.next(), chars.next());
    if c2.is_none() {
        // Single character.
        c1
    } else {
        // Check for special characters.
        match key {
            "Backspace" => Some(8 as char),
            "Delete" => Some(127 as char),
            _ => None,
        }
    }
}