ascii_forge/

window.rs

pub use crate::prelude::*;

use crossterm::{
    cursor::{self, Hide, MoveTo, Show},
    event, execute, queue,
    terminal::{self, *},
    tty::IsTty,
};
use std::{
    io::{self, Stdout, Write},
    panic::{set_hook, take_hook},
    time::Duration,
};

#[derive(Default)]
pub struct Inline {
    active: bool,
    kitty: bool,
    start: u16,
}

impl AsMut<Buffer> for Window {
    fn as_mut(&mut self) -> &mut Buffer {
        self.buffer_mut()
    }
}

/// The main window behind the application.
/// Represents the terminal window, allowing it to be used similar to a buffer,
/// but has extra event handling.
/**
```rust, no_run
# use ascii_forge::prelude::*;
# fn main() -> std::io::Result<()> {
let mut window = Window::init()?;
render!(window, (10, 10) => [ "Element Here!" ]);
# Ok(())
# }
```
*/
pub struct Window {
    io: io::Stdout,
    buffers: [Buffer; 2],
    active_buffer: usize,
    events: Vec<Event>,

    last_cursor: (bool, Vec2, SetCursorStyle),

    cursor_visible: bool,
    cursor: Vec2,
    cursor_style: SetCursorStyle,

    // Input Helpers,
    mouse_pos: Vec2,
    // Inlining
    inline: Option<Inline>,
    // Event Handling
    just_resized: bool,
}

impl Default for Window {
    fn default() -> Self {
        Self::init().expect("Init should have succeeded")
    }
}

impl Window {
    /// Creates a new window from the given stdout.
    /// Please prefer to use init as it will do all of the terminal init stuff.
    pub fn new(io: io::Stdout) -> io::Result<Self> {
        Ok(Self {
            io,
            buffers: [
                Buffer::new_filled(size()?, ' '),
                Buffer::new_filled(size()?, ' '),
            ],
            active_buffer: 0,
            events: vec![],
            last_cursor: (false, vec2(0, 0), SetCursorStyle::SteadyBlock),
            cursor_visible: false,
            cursor_style: SetCursorStyle::SteadyBlock,
            cursor: vec2(0, 0),
            mouse_pos: vec2(0, 0),
            inline: None,
            just_resized: false,
        })
    }

    /// Creates a new window built for inline using the given Stdout and height.
    pub fn new_inline(io: io::Stdout, height: u16) -> io::Result<Self> {
        let size = vec2(size()?.0, height);
        Ok(Self {
            io,
            buffers: [Buffer::new_filled(size, ' '), Buffer::new_filled(size, ' ')],
            active_buffer: 0,
            events: vec![],
            last_cursor: (false, vec2(0, 0), SetCursorStyle::SteadyBlock),
            cursor_visible: false,
            cursor_style: SetCursorStyle::SteadyBlock,
            cursor: vec2(0, 0),
            mouse_pos: vec2(0, 0),
            inline: Some(Inline::default()),
            just_resized: false,
        })
    }

    /// Initializes a window that is prepared for inline rendering.
    /// Height is the number of columns that your terminal will need.
    pub fn init_inline(height: u16) -> io::Result<Self> {
        let stdout = io::stdout();
        assert!(stdout.is_tty());
        Window::new_inline(stdout, height)
    }

    /// Initializes the window, and returns a new Window for your use.
    pub fn init() -> io::Result<Self> {
        enable_raw_mode()?;
        let mut stdout = io::stdout();
        assert!(stdout.is_tty());
        execute!(
            stdout,
            EnterAlternateScreen,
            EnableMouseCapture,
            EnableFocusChange,
            Hide,
            DisableLineWrap,
        )?;
        Window::new(stdout)
    }

    /// Enables the kitty keyboard protocol
    pub fn keyboard(&mut self) -> io::Result<()> {
        if let Ok(t) = terminal::supports_keyboard_enhancement() {
            if !t {
                return Err(io::Error::new(
                    io::ErrorKind::Unsupported,
                    "Terminal doesn't support the kitty keyboard protocol",
                ));
            }
            if let Some(inline) = &mut self.inline {
                inline.kitty = true;
            } else {
                execute!(
                    self.io(),
                    PushKeyboardEnhancementFlags(KeyboardEnhancementFlags::all())
                )?;
            }
            Ok(())
        } else {
            Err(io::Error::new(
                io::ErrorKind::Unsupported,
                "Terminal doesn't support the kitty keyboard protocol",
            ))
        }
    }

    /// Returns the active Buffer, as a reference.
    pub fn buffer(&self) -> &Buffer {
        &self.buffers[self.active_buffer]
    }

    /// Returns the active Buffer, as a mutable reference.
    pub fn buffer_mut(&mut self) -> &mut Buffer {
        &mut self.buffers[self.active_buffer]
    }

    /// Swaps the buffers, clearing the old buffer. Used automatically by the window's update method.
    pub fn swap_buffers(&mut self) {
        self.active_buffer = 1 - self.active_buffer;
        self.buffers[self.active_buffer].fill(' ');
    }

    /// Returns the current known size of the buffer's window.
    pub fn size(&self) -> Vec2 {
        self.buffer().size()
    }

    /// Restores the window to it's previous state from before the window's init method.
    /// If the window is inline, restore the inline render
    pub fn restore(&mut self) -> io::Result<()> {
        if terminal::supports_keyboard_enhancement().is_ok() {
            queue!(self.io, PopKeyboardEnhancementFlags)?;
        }
        if let Some(inline) = &self.inline {
            execute!(
                self.io,
                DisableMouseCapture,
                DisableFocusChange,
                PopKeyboardEnhancementFlags,
                Show,
            )?;
            if terminal::size()?.1 != inline.start + 1 {
                print!(
                    "{}",
                    "\n".repeat(self.buffers[self.active_buffer].size().y as usize)
                );
            }
            disable_raw_mode()?;
            Ok(())
        } else {
            execute!(
                self.io,
                PopKeyboardEnhancementFlags,
                LeaveAlternateScreen,
                DisableMouseCapture,
                DisableFocusChange,
                Show,
                EnableLineWrap,
            )?;
            disable_raw_mode()
        }
    }

    /// Renders the window to the screen. should really only be used by the update method, but if you need a custom system, you can use this.
    pub fn render(&mut self) -> io::Result<()> {
        if self.inline.is_some() {
            if !self.inline.as_ref().expect("Inline should be some").active {
                // Make room for the inline render
                print!("{}", "\n".repeat(self.buffer().size().y as usize));

                enable_raw_mode()?;

                execute!(
                    self.io,
                    EnableMouseCapture,
                    EnableFocusChange,
                    DisableLineWrap,
                    Hide,
                )?;
                if self.inline.as_ref().expect("Inline should be some").kitty {
                    execute!(
                        self.io,
                        PushKeyboardEnhancementFlags(KeyboardEnhancementFlags::all())
                    )?;
                }
                let inline = self.inline.as_mut().expect("Inline should be some");
                inline.active = true;
                inline.start = cursor::position()?.1;
            }

            for (loc, cell) in
                self.buffers[1 - self.active_buffer].diff(&self.buffers[self.active_buffer])
            {
                queue!(
                    self.io,
                    cursor::MoveTo(
                        loc.x,
                        self.inline.as_ref().expect("Inline should be some").start
                            - self.buffers[self.active_buffer].size().y
                            + loc.y
                    ),
                    Print(cell),
                )?;
            }

            queue!(
                self.io,
                cursor::MoveTo(
                    0,
                    self.inline.as_ref().expect("Inline should be some").start
                        - self.buffers[self.active_buffer].size().y
                )
            )?;
        } else {
            if self.just_resized {
                self.just_resized = false;
                let cell = self.buffers[self.active_buffer].size();
                for x in 0..cell.x {
                    for y in 0..cell.y {
                        let cell = self.buffers[self.active_buffer]
                            .get((x, y))
                            .expect("Cell should be in bounds");
                        queue!(self.io, cursor::MoveTo(x, y), Print(cell))?;
                    }
                }
            }

            for (loc, cell) in
                self.buffers[1 - self.active_buffer].diff(&self.buffers[self.active_buffer])
            {
                queue!(self.io, cursor::MoveTo(loc.x, loc.y), Print(cell))?;
            }
        }
        Ok(())
    }

    /// Handles events, and renders the screen.
    pub fn update(&mut self, poll: Duration) -> io::Result<()> {
        // Render Window
        self.render()?;
        self.swap_buffers();
        self.render_cursor()?;
        // Flush Render To Stdout
        self.io.flush()?;
        // Poll For Events
        self.handle_event(poll)?;
        Ok(())
    }

    pub fn render_cursor(&mut self) -> io::Result<()> {
        // Get the current cursor position
        let cursor_pos = cursor::position()?;
        if self.cursor_style != self.last_cursor.2
            || self.cursor != cursor_pos.into()
            || self.cursor != self.last_cursor.1
            || self.cursor_visible != self.last_cursor.0
        {
            if self.cursor_visible {
                let cursor = self.cursor;
                let style = self.cursor_style;

                // Calculate the actual position based on inline rendering
                let actual_pos = if let Some(inline) = &self.inline {
                    vec2(
                        cursor.x,
                        inline.start - self.buffers[self.active_buffer].size().y + cursor.y,
                    )
                } else {
                    cursor
                };

                queue!(self.io(), MoveTo(actual_pos.x, actual_pos.y), style, Show)?;
            } else {
                queue!(self.io(), Hide)?;
            }
        }
        self.last_cursor = (self.cursor_visible, self.cursor, self.cursor_style);
        Ok(())
    }

    /// Handles events. Used automatically by the update method, so no need to use it unless update is being used.
    pub fn handle_event(&mut self, poll: Duration) -> io::Result<()> {
        self.events = vec![];
        if event::poll(poll)? {
            // Get all queued events
            while event::poll(Duration::ZERO)? {
                let event = event::read()?;
                match event {
                    Event::Resize(width, height) => {
                        if self.inline.is_none() {
                            self.buffers = [
                                Buffer::new_filled((width, height), ' '),
                                Buffer::new_filled((width, height), ' '),
                            ];
                            self.just_resized = true;
                        }
                    }
                    Event::Mouse(MouseEvent { column, row, .. }) => {
                        self.mouse_pos = vec2(column, row)
                    }
                    _ => {}
                }
                self.events.push(event);
            }
        }
        Ok(())
    }

    /// Returns whether the cursor is visible
    pub fn cursor_visible(&self) -> bool {
        self.cursor_visible
    }

    /// Returns the current cursor position
    pub fn cursor(&self) -> Vec2 {
        self.cursor
    }

    /// Returns the current cursor style
    pub fn cursor_style(&self) -> SetCursorStyle {
        self.cursor_style
    }

    /// Sets the cursor visibility
    pub fn set_cursor_visible(&mut self, visible: bool) {
        self.cursor_visible = visible;
    }

    /// Sets the cursor position, clamping to window bounds
    pub fn set_cursor(&mut self, pos: Vec2) {
        let size = self.size();
        self.cursor.x = pos.x.min(size.x.saturating_sub(1));
        self.cursor.y = pos.y.min(size.y.saturating_sub(1));
    }

    /// Sets the cursor style
    pub fn set_cursor_style(&mut self, style: SetCursorStyle) {
        self.cursor_style = style;
    }

    /// Move the cursor by a given distance
    pub fn move_cursor(&mut self, x: i16, y: i16) {
        let size = self.size();
        self.cursor.x = self
            .cursor
            .x
            .saturating_add_signed(x)
            .min(size.x.saturating_sub(1));
        self.cursor.y = self
            .cursor
            .y
            .saturating_add_signed(y)
            .min(size.y.saturating_sub(1));
    }

    pub fn mouse_pos(&self) -> Vec2 {
        self.mouse_pos
    }

    /// Pushes an event into the state
    /// Could be usefull with a custom event loop
    /// or for keyboard control from elsewhere
    pub fn insert_event(&mut self, event: Event) {
        self.events.push(event);
    }

    /// Returns the current event for the frame, as a reference.
    pub fn events(&self) -> &Vec<Event> {
        &self.events
    }

    /// Returns true if the mouse cursor is hovering the given rect.
    pub fn hover<V: Into<Vec2>>(&self, loc: V, size: V) -> io::Result<bool> {
        let loc = loc.into();
        let size = size.into();
        let pos: Vec2 = self.mouse_pos();
        Ok(pos.x <= loc.x + size.x && pos.x >= loc.x && pos.y <= loc.y + size.y && pos.y >= loc.y)
    }

    pub fn io(&mut self) -> &mut Stdout {
        &mut self.io
    }
}

/// A macro that allows you to quickly check an event based off of a pattern
/// Takes in the window, a pattern for the if let statement, and finally a closure.
/// This closure could be anything that returns a bool.
///
/// Underneath, the event! macro runs an if let on your pattern checking for any of the
/// Events to be true from your given closure.
/**
Example
```rust, no_run
# use ascii_forge::prelude::*;
# fn main() -> std::io::Result<()> {
# let mut window = Window::init()?;
event!(window, Event::Key(e) => e.code == KeyCode::Char('q'));
# Ok(())
# }
```
*/
#[macro_export]
macro_rules! event {
    ($window:expr, $event_type:pat => $($closure:tt)*) => {
        $window.events().iter().any(|e| {
            if let $event_type = e {
                $($closure)*
            } else {
                false
            }
        })
    };
}

/// Enables a panic hook to help you terminal still look pretty.
pub fn handle_panics() {
    let original_hook = take_hook();
    set_hook(Box::new(move |e| {
        Window::new(io::stdout())
            .expect("Window should have created for panic")
            .restore()
            .expect("Window should have exited for panic");
        original_hook(e);
    }))
}

impl Drop for Window {
    fn drop(&mut self) {
        self.restore().expect("Restoration should have succeded");
    }
}