cursive/cursive-core/src/cursive.rs
2020-07-03 09:17:50 -07:00

1061 lines
33 KiB
Rust

use std::any::Any;
use std::num::NonZeroU32;
#[cfg(feature = "toml")]
use std::path::Path;
use std::time::Duration;
use crossbeam_channel::{self, Receiver, Sender};
use crate::{
backend, direction,
event::{Event, EventResult},
printer::Printer,
theme,
view::{self, Finder, IntoBoxedView, Position, View},
views::{self, LayerPosition},
Dump, Vec2,
};
static DEBUG_VIEW_NAME: &str = "_cursive_debug_view";
// How long we wait between two empty input polls
const INPUT_POLL_DELAY_MS: u64 = 30;
/// Central part of the cursive library.
///
/// It initializes ncurses on creation and cleans up on drop.
/// To use it, you should populate it with views, layouts, and callbacks,
/// then start the event loop with `run()`.
///
/// It uses a list of screen, with one screen active at a time.
pub struct Cursive {
theme: theme::Theme,
// The main view
root: views::OnEventView<views::ScreensView<views::StackView>>,
menubar: views::Menubar,
// Last layer sizes of the stack view.
// If it changed, clear the screen.
last_sizes: Vec<Vec2>,
running: bool,
backend: Box<dyn backend::Backend>,
// Handle asynchronous callbacks
cb_source: Receiver<Box<dyn FnOnce(&mut Cursive) + Send>>,
cb_sink: Sender<Box<dyn FnOnce(&mut Cursive) + Send>>,
// User-provided data.
user_data: Box<dyn Any>,
// Handle auto-refresh when no event is received.
fps: Option<NonZeroU32>,
boring_frame_count: u32,
}
/// Identifies a screen in the cursive root.
pub type ScreenId = usize;
/// Convenient alias to the result of `Cursive::cb_sink`.
///
/// # Notes
///
/// Callbacks need to be `Send`, which can be limiting in some cases.
///
/// In some case [`send_wrapper`] may help you work around that.
///
/// [`send_wrapper`]: https://crates.io/crates/send_wrapper
pub type CbSink = Sender<Box<dyn FnOnce(&mut Cursive) + Send>>;
impl Cursive {
/// Shortcut for `Cursive::try_new` with non-failible init function.
///
/// You probably don't want to use this function directly, unless you're
/// using a non-standard backend. Built-in backends have dedicated functions.
///
/// # Examples
///
/// ```rust,no_run
/// # use cursive_core::{Cursive, backend};
/// let siv = Cursive::new(backend::Dummy::init);
/// ```
pub fn new<F>(backend_init: F) -> Self
where
F: FnOnce() -> Box<dyn backend::Backend>,
{
Self::try_new::<_, ()>(|| Ok(backend_init())).unwrap()
}
/// Creates a new Cursive root, and initialize the back-end.
///
/// You probably don't want to use this function directly, unless you're
/// using a non-standard backend. Built-in backends have dedicated functions in the
/// [`CursiveExt`] trait.
///
/// [`CursiveExt`]: https://docs.rs/cursive/0/cursive/trait.CursiveExt.html
pub fn try_new<F, E>(backend_init: F) -> Result<Self, E>
where
F: FnOnce() -> Result<Box<dyn backend::Backend>, E>,
{
let theme = theme::load_default();
let (cb_sink, cb_source) = crossbeam_channel::unbounded();
let backend = backend_init()?;
let mut cursive = Cursive {
theme,
root: views::OnEventView::new(views::ScreensView::single_screen(
views::StackView::new(),
)),
last_sizes: Vec::new(),
menubar: views::Menubar::new(),
running: true,
cb_source,
cb_sink,
backend,
fps: None,
boring_frame_count: 0,
user_data: Box::new(()),
};
cursive.reset_default_callbacks();
Ok(cursive)
}
/// Creates a new Cursive root using a [dummy backend].
///
/// Nothing will be output. This is mostly here for tests.
///
/// [dummy backend]: backend::Dummy
pub fn dummy() -> Self {
Self::new(backend::Dummy::init)
}
/// Sets some data to be stored in Cursive.
///
/// It can later on be accessed with `Cursive::user_data()`
pub fn set_user_data<T: Any>(&mut self, user_data: T) {
self.user_data = Box::new(user_data);
}
/// Attempts to access the user-provided data.
///
/// If some data was set previously with the same type, returns a
/// reference to it.
///
/// If nothing was set or if the type is different, returns `None`.
pub fn user_data<T: Any>(&mut self) -> Option<&mut T> {
self.user_data.downcast_mut()
}
/// Attemps to take by value the current user-data.
///
/// If successful, this will replace the current user-data with the unit
/// type `()`.
///
/// If the current user data is not of the requested type, `None` will be
/// returned.
///
/// # Examples
///
/// ```rust
/// let mut siv = cursive_core::Cursive::dummy();
///
/// // Start with a simple `Vec<i32>` as user data.
/// siv.set_user_data(vec![1i32, 2, 3]);
/// assert_eq!(siv.user_data::<Vec<i32>>(), Some(&mut vec![1i32, 2, 3]));
///
/// // Let's mutate the data a bit.
/// siv.with_user_data(|numbers: &mut Vec<i32>| numbers.push(4));
///
/// // If mutable reference is not enough, we can take the data by value.
/// let data: Vec<i32> = siv.take_user_data().unwrap();
/// assert_eq!(data, vec![1i32, 2, 3, 4]);
///
/// // At this point the user data was removed and is no longer available.
/// assert_eq!(siv.user_data::<Vec<i32>>(), None);
/// ```
pub fn take_user_data<T: Any>(&mut self) -> Option<T> {
// Start by taking the user data and replacing it with a dummy.
let user_data = std::mem::replace(&mut self.user_data, Box::new(()));
// Downcast the data to the requested type.
// If it works, unbox it.
// It if doesn't, take it back.
user_data
.downcast()
.map_err(|user_data| {
// If we asked for the wrong type, put it back.
self.user_data = user_data;
})
.map(|boxed| *boxed)
.ok()
}
/// Runs the given closure on the stored user data, if any.
///
/// If no user data was supplied, or if the type is different, nothing
/// will be run.
///
/// Otherwise, the result will be returned.
pub fn with_user_data<F, T, R>(&mut self, f: F) -> Option<R>
where
F: FnOnce(&mut T) -> R,
T: Any,
{
self.user_data().map(f)
}
/// Show the debug console.
///
/// Currently, this will show logs if [`logger::init()`](crate::logger::init()) was called.
pub fn show_debug_console(&mut self) {
self.add_layer(
views::Dialog::around(
views::ScrollView::new(views::NamedView::new(
DEBUG_VIEW_NAME,
views::DebugView::new(),
))
.scroll_x(true),
)
.title("Debug console"),
);
}
/// Show the debug console, or hide it if it's already visible.
///
/// # Examples
///
/// ```rust
/// # use cursive_core::Cursive;
/// # let mut siv = Cursive::dummy();
/// siv.add_global_callback('~', Cursive::toggle_debug_console);
/// ```
pub fn toggle_debug_console(&mut self) {
if let Some(pos) =
self.screen_mut().find_layer_from_name(DEBUG_VIEW_NAME)
{
self.screen_mut().remove_layer(pos);
} else {
self.show_debug_console();
}
}
/// Returns a sink for asynchronous callbacks.
///
/// Returns the sender part of a channel, that allows to send
/// callbacks to `self` from other threads.
///
/// Callbacks will be executed in the order
/// of arrival on the next event cycle.
///
/// # Notes
///
/// Callbacks need to be `Send`, which can be limiting in some cases.
///
/// In some case [`send_wrapper`] may help you work around that.
///
/// [`send_wrapper`]: https://crates.io/crates/send_wrapper
///
/// # Examples
///
/// ```rust
/// # use cursive_core::*;
/// let mut siv = Cursive::dummy();
///
/// // quit() will be called during the next event cycle
/// siv.cb_sink().send(Box::new(|s| s.quit())).unwrap();
/// ```
pub fn cb_sink(&self) -> &CbSink {
&self.cb_sink
}
/// Selects the menubar.
pub fn select_menubar(&mut self) {
self.menubar.take_focus(direction::Direction::none());
}
/// Sets the menubar autohide feature.
///
/// * When enabled (default), the menu is only visible when selected.
/// * When disabled, the menu is always visible and reserves the top row.
pub fn set_autohide_menu(&mut self, autohide: bool) {
self.menubar.autohide = autohide;
}
/// Access the menu tree used by the menubar.
///
/// This allows to add menu items to the menubar.
///
/// # Examples
///
/// ```rust
/// # use cursive_core::{Cursive, event};
/// # use cursive_core::views::{Dialog};
/// # use cursive_core::traits::*;
/// # use cursive_core::menu::*;
/// #
/// let mut siv = Cursive::dummy();
///
/// siv.menubar()
/// .add_subtree("File",
/// MenuTree::new()
/// .leaf("New", |s| s.add_layer(Dialog::info("New file!")))
/// .subtree("Recent", MenuTree::new().with(|tree| {
/// for i in 1..100 {
/// tree.add_leaf(format!("Item {}", i), |_| ())
/// }
/// }))
/// .delimiter()
/// .with(|tree| {
/// for i in 1..10 {
/// tree.add_leaf(format!("Option {}", i), |_| ());
/// }
/// })
/// .delimiter()
/// .leaf("Quit", |s| s.quit()))
/// .add_subtree("Help",
/// MenuTree::new()
/// .subtree("Help",
/// MenuTree::new()
/// .leaf("General", |s| {
/// s.add_layer(Dialog::info("Help message!"))
/// })
/// .leaf("Online", |s| {
/// s.add_layer(Dialog::info("Online help?"))
/// }))
/// .leaf("About",
/// |s| s.add_layer(Dialog::info("Cursive v0.0.0"))));
///
/// siv.add_global_callback(event::Key::Esc, |s| s.select_menubar());
/// ```
pub fn menubar(&mut self) -> &mut views::Menubar {
&mut self.menubar
}
/// Returns the currently used theme.
pub fn current_theme(&self) -> &theme::Theme {
&self.theme
}
/// Sets the current theme.
pub fn set_theme(&mut self, theme: theme::Theme) {
self.theme = theme;
self.clear();
}
/// Updates the current theme.
pub fn update_theme(&mut self, f: impl FnOnce(&mut theme::Theme)) {
// We don't just expose a `current_theme_mut` because we may want to
// run some logic _after_ setting the theme.
// Though right now, it's only clearing the screen, so...
let mut theme = self.theme.clone();
f(&mut theme);
self.set_theme(theme);
}
/// Clears the screen.
///
/// Users rarely have to call this directly.
pub fn clear(&mut self) {
self.backend
.clear(self.theme.palette[theme::PaletteColor::Background]);
}
/// Loads a theme from the given file.
///
/// `filename` must point to a valid toml file.
///
/// Must have the `toml` feature enabled.
#[cfg(feature = "toml")]
pub fn load_theme_file<P: AsRef<Path>>(
&mut self,
filename: P,
) -> Result<(), theme::Error> {
theme::load_theme_file(filename).map(|theme| self.set_theme(theme))
}
/// Loads a theme from the given string content.
///
/// Content must be valid toml.
///
/// Must have the `toml` feature enabled.
#[cfg(feature = "toml")]
pub fn load_toml(&mut self, content: &str) -> Result<(), theme::Error> {
theme::load_toml(content).map(|theme| self.set_theme(theme))
}
/// Sets the refresh rate, in frames per second.
///
/// Note that the actual frequency is not guaranteed.
///
/// Between 0 and 30. Call with `fps = 0` to disable (default value).
pub fn set_fps(&mut self, fps: u32) {
self.fps = NonZeroU32::new(fps);
}
/// Enables or disables automatic refresh of the screen.
///
/// This is a shortcut to call `set_fps` with `30` or `0` depending on
/// `autorefresh`.
pub fn set_autorefresh(&mut self, autorefresh: bool) {
self.set_fps(if autorefresh { 30 } else { 0 });
}
/// Returns a reference to the currently active screen.
pub fn screen(&self) -> &views::StackView {
self.root.get_inner().screen().unwrap()
}
/// Returns a mutable reference to the currently active screen.
pub fn screen_mut(&mut self) -> &mut views::StackView {
self.root.get_inner_mut().screen_mut().unwrap()
}
/// Returns the id of the currently active screen.
pub fn active_screen(&self) -> ScreenId {
self.root.get_inner().active_screen()
}
/// Adds a new screen, and returns its ID.
pub fn add_screen(&mut self) -> ScreenId {
self.root
.get_inner_mut()
.add_screen(views::StackView::new())
}
/// Convenient method to create a new screen, and set it as active.
pub fn add_active_screen(&mut self) -> ScreenId {
let res = self.add_screen();
self.set_screen(res);
res
}
/// Sets the active screen. Panics if no such screen exist.
pub fn set_screen(&mut self, screen_id: ScreenId) {
self.root.get_inner_mut().set_active_screen(screen_id);
}
/// Tries to find the view pointed to by the given selector.
///
/// Runs a closure on the view once it's found, and return the
/// result.
///
/// If the view is not found, or if it is not of the asked type,
/// returns None.
///
/// # Examples
///
/// ```rust
/// # use cursive_core::{Cursive, views, view};
/// # use cursive_core::traits::*;
/// let mut siv = Cursive::dummy();
///
/// siv.add_layer(views::TextView::new("Text #1").with_name("text"));
///
/// siv.add_global_callback('p', |s| {
/// s.call_on(
/// &view::Selector::Id("text"),
/// |view: &mut views::TextView| {
/// view.set_content("Text #2");
/// },
/// );
/// });
/// ```
pub fn call_on<V, F, R>(
&mut self,
sel: &view::Selector<'_>,
callback: F,
) -> Option<R>
where
V: View,
F: FnOnce(&mut V) -> R,
{
self.root.call_on(sel, callback)
}
/// Tries to find the view identified by the given id.
///
/// Convenient method to use `call_on` with a `view::Selector::Id`.
///
/// # Examples
///
/// ```rust
/// # use cursive_core::{Cursive, views};
/// # use cursive_core::traits::*;
/// let mut siv = Cursive::dummy();
///
/// siv.add_layer(views::TextView::new("Text #1")
/// .with_name("text"));
///
/// siv.add_global_callback('p', |s| {
/// s.call_on_name("text", |view: &mut views::TextView| {
/// view.set_content("Text #2");
/// });
/// });
/// ```
pub fn call_on_name<V, F, R>(
&mut self,
name: &str,
callback: F,
) -> Option<R>
where
V: View,
F: FnOnce(&mut V) -> R,
{
self.call_on(&view::Selector::Name(name), callback)
}
/// Same as [`call_on_name`](Cursive::call_on_name).
#[deprecated(note = "`call_on_id` is being renamed to `call_on_name`")]
pub fn call_on_id<V, F, R>(&mut self, id: &str, callback: F) -> Option<R>
where
V: View,
F: FnOnce(&mut V) -> R,
{
self.call_on_name(id, callback)
}
/// Convenient method to find a view wrapped in [`NamedView`].
///
/// This looks for a `NamedView<V>` with the given name, and return
/// a [`ViewRef`] to the wrapped view. The `ViewRef` implements
/// `DerefMut<Target=T>`, so you can treat it just like a `&mut T`.
///
/// # Examples
///
/// ```rust
/// # use cursive_core::Cursive;
/// # use cursive_core::views::{TextView, ViewRef};
/// # let mut siv = Cursive::dummy();
/// use cursive_core::traits::Identifiable;
///
/// siv.add_layer(TextView::new("foo").with_name("id"));
///
/// // Could be called in a callback
/// let mut view: ViewRef<TextView> = siv.find_name("id").unwrap();
/// view.set_content("bar");
/// ```
///
/// Note that you must specify the exact type for the view you're after; for example, using the
/// wrong item type in a `SelectView` will not find anything:
///
/// ```rust
/// # use cursive_core::Cursive;
/// # use cursive_core::views::{SelectView};
/// # let mut siv = Cursive::dummy();
/// use cursive_core::traits::Identifiable;
///
/// let select = SelectView::new().item("zero", 0u32).item("one", 1u32);
/// siv.add_layer(select.with_name("select"));
///
/// // Specifying a wrong type will not return anything.
/// assert!(siv.find_name::<SelectView<String>>("select").is_none());
///
/// // Omitting the type will use the default type, in this case `String`.
/// assert!(siv.find_name::<SelectView>("select").is_none());
///
/// // But with the correct type, it works fine.
/// assert!(siv.find_name::<SelectView<u32>>("select").is_some());
/// ```
///
/// [`NamedView`]: views::NamedView
/// [`ViewRef`]: views::ViewRef
pub fn find_name<V>(&mut self, id: &str) -> Option<views::ViewRef<V>>
where
V: View,
{
self.call_on_name(id, views::NamedView::<V>::get_mut)
}
/// Same as [`find_name`](Cursive::find_name).
#[deprecated(note = "`find_id` is being renamed to `find_name`")]
pub fn find_id<V>(&mut self, id: &str) -> Option<views::ViewRef<V>>
where
V: View,
{
self.find_name(id)
}
/// Moves the focus to the view identified by `name`.
///
/// Convenient method to call `focus` with a [`view::Selector::Name`].
pub fn focus_name(&mut self, name: &str) -> Result<(), ()> {
self.focus(&view::Selector::Name(name))
}
/// Same as [`focus_name`](Cursive::focus_name).
#[deprecated(note = "`focus_id` is being renamed to `focus_name`")]
pub fn focus_id(&mut self, id: &str) -> Result<(), ()> {
self.focus(&view::Selector::Name(id))
}
/// Moves the focus to the view identified by `sel`.
pub fn focus(&mut self, sel: &view::Selector<'_>) -> Result<(), ()> {
self.root.focus_view(sel)
}
/// Adds a global callback.
///
/// Will be triggered on the given key press when no view catches it.
///
/// # Examples
///
/// ```rust
/// # use cursive_core::*;
/// let mut siv = Cursive::dummy();
///
/// siv.add_global_callback('q', |s| s.quit());
/// ```
pub fn add_global_callback<F, E: Into<Event>>(&mut self, event: E, cb: F)
where
F: FnMut(&mut Cursive) + 'static,
{
self.set_on_post_event(event.into(), cb);
}
/// Registers a callback for ignored events.
///
/// This is the same as `add_global_callback`, but can register any `EventTrigger`.
pub fn set_on_post_event<F, E>(&mut self, trigger: E, cb: F)
where
F: FnMut(&mut Cursive) + 'static,
E: Into<crate::event::EventTrigger>,
{
self.root.set_on_event(trigger, crate::immut1!(cb));
}
/// Registers a priotity callback.
///
/// If an event matches the given trigger, it will not be sent to the view
/// tree and will go to the given callback instead.
///
/// Note that regular "post-event" callbacks will also be skipped for
/// these events.
pub fn set_on_pre_event<F, E>(&mut self, trigger: E, cb: F)
where
F: FnMut(&mut Cursive) + 'static,
E: Into<crate::event::EventTrigger>,
{
self.root.set_on_pre_event(trigger, crate::immut1!(cb));
}
/// Registers an inner priority callback.
///
/// See [`OnEventView`] for more information.
///
/// [`OnEventView`]: crate::views::OnEventView::set_on_pre_event_inner()
pub fn set_on_pre_event_inner<E, F>(&mut self, trigger: E, cb: F)
where
E: Into<crate::event::EventTrigger>,
F: Fn(&Event) -> Option<EventResult> + 'static,
{
self.root
.set_on_pre_event_inner(trigger, move |_, event| cb(event));
}
/// Registers an inner callback.
///
/// See [`OnEventView`] for more information.
///
/// [`OnEventView`]: crate::views::OnEventView::set_on_event_inner()
pub fn set_on_event_inner<E, F>(&mut self, trigger: E, cb: F)
where
E: Into<crate::event::EventTrigger>,
F: Fn(&Event) -> Option<EventResult> + 'static,
{
self.root
.set_on_event_inner(trigger, move |_, event| cb(event));
}
/// Sets the only global callback for the given event.
///
/// Any other callback for this event will be removed.
///
/// See also [`Cursive::add_global_callback`].
pub fn set_global_callback<F, E: Into<Event>>(&mut self, event: E, cb: F)
where
F: FnMut(&mut Cursive) + 'static,
{
let event = event.into();
self.clear_global_callbacks(event.clone());
self.add_global_callback(event, cb);
}
/// Fetches the type name of a view in the tree.
pub fn debug_name(&mut self, name: &str) -> Option<&'static str> {
let mut result = None;
self.root.call_on_any(
&view::Selector::Name(name),
&mut |v: &mut dyn crate::View| result = Some(v.type_name()),
);
result
}
/// Removes any callback tied to the given event.
///
/// # Examples
///
/// ```rust
/// use cursive_core::Cursive;
/// let mut siv = Cursive::dummy();
///
/// siv.add_global_callback('q', |s| s.quit());
/// siv.clear_global_callbacks('q');
/// ```
pub fn clear_global_callbacks<E>(&mut self, event: E)
where
E: Into<Event>,
{
let event = event.into();
self.root.clear_event(event);
}
/// This resets the default callbacks.
///
/// Currently this mostly includes exiting on Ctrl-C.
pub fn reset_default_callbacks(&mut self) {
self.set_on_pre_event(Event::CtrlChar('c'), |s| s.quit());
self.set_on_pre_event(Event::Exit, |s| s.quit());
self.set_on_pre_event(Event::WindowResize, |s| s.clear());
}
/// Add a layer to the current screen.
///
/// # Examples
///
/// ```rust
/// use cursive_core::{Cursive, views};
/// let mut siv = Cursive::dummy();
///
/// siv.add_layer(views::TextView::new("Hello world!"));
/// ```
pub fn add_layer<T>(&mut self, view: T)
where
T: IntoBoxedView,
{
self.screen_mut().add_layer(view);
}
/// Adds a new full-screen layer to the current screen.
///
/// Fullscreen layers have no shadow.
pub fn add_fullscreen_layer<T>(&mut self, view: T)
where
T: IntoBoxedView,
{
self.screen_mut().add_fullscreen_layer(view);
}
/// Convenient method to remove a layer from the current screen.
pub fn pop_layer(&mut self) -> Option<Box<dyn View>> {
self.screen_mut().pop_layer()
}
/// Convenient stub forwarding layer repositioning.
pub fn reposition_layer(
&mut self,
layer: LayerPosition,
position: Position,
) {
self.screen_mut().reposition_layer(layer, position);
}
/// Processes an event.
///
/// * If the menubar is active, it will be handled the event.
/// * The view tree will be handled the event.
/// * If ignored, global_callbacks will be checked for this event.
pub fn on_event(&mut self, event: Event) {
if let Event::Mouse {
event, position, ..
} = event
{
if event.grabs_focus()
&& !self.menubar.autohide
&& !self.menubar.has_submenu()
&& position.y == 0
{
self.select_menubar();
}
}
if self.menubar.receive_events() {
self.menubar.on_event(event).process(self);
} else {
let offset = if self.menubar.autohide { 0 } else { 1 };
let result =
View::on_event(&mut self.root, event.relativized((0, offset)));
if let EventResult::Consumed(Some(cb)) = result {
cb(self);
}
}
}
/// Returns the size of the screen, in characters.
pub fn screen_size(&self) -> Vec2 {
self.backend.screen_size()
}
fn layout(&mut self) {
let size = self.screen_size();
let offset = if self.menubar.autohide { 0 } else { 1 };
let size = size.saturating_sub((0, offset));
self.root.layout(size);
}
fn draw(&mut self) {
// TODO: do not allocate in the default, fast path?
let sizes = self.screen().layer_sizes();
if self.last_sizes != sizes {
// TODO: Maybe we only need to clear if the _max_ size differs?
// Or if the positions change?
self.clear();
self.last_sizes = sizes;
}
let printer =
Printer::new(self.screen_size(), &self.theme, &*self.backend);
let selected = self.menubar.receive_events();
// Print the stackview background before the menubar
let offset = if self.menubar.autohide { 0 } else { 1 };
let sv_printer = printer.offset((0, offset)).focused(!selected);
self.root.draw(&sv_printer);
self.root.get_inner().draw_bg(&sv_printer);
// Draw the currently active screen
// If the menubar is active, nothing else can be.
// Draw the menubar?
if self.menubar.visible() {
let printer = printer.focused(self.menubar.receive_events());
self.menubar.draw(&printer);
}
// finally draw stackview layers
// using variables from above
self.root.get_inner().draw_fg(&sv_printer);
}
/// Returns `true` until [`quit(&mut self)`] is called.
///
/// [`quit(&mut self)`]: #method.quit
pub fn is_running(&self) -> bool {
self.running
}
/// Runs the event loop.
///
/// It will wait for user input (key presses)
/// and trigger callbacks accordingly.
///
/// Internally, it calls [`step(&mut self)`] until [`quit(&mut self)`] is
/// called.
///
/// After this function returns, you can call it again and it will start a
/// new loop.
///
/// [`step(&mut self)`]: #method.step
/// [`quit(&mut self)`]: #method.quit
pub fn run(&mut self) {
self.running = true;
self.refresh();
// And the big event loop begins!
while self.running {
self.step();
}
}
/// Performs a single step from the event loop.
///
/// Useful if you need tighter control on the event loop.
/// Otherwise, [`run(&mut self)`] might be more convenient.
///
/// Returns `true` if an input event or callback was received
/// during this step, and `false` otherwise.
///
/// [`run(&mut self)`]: #method.run
pub fn step(&mut self) -> bool {
let received_something = self.process_events();
self.post_events(received_something);
received_something
}
/// Performs the first half of `Self::step()`.
///
/// This is an advanced method for fine-tuned manual stepping;
/// you probably want [`run`][1] or [`step`][2].
///
/// This processes any pending event or callback. After calling this,
/// you will want to call [`post_events`][3] with the result from this
/// function.
///
/// Returns `true` if an event or callback was received,
/// and `false` otherwise.
///
/// [1]: Cursive::run()
/// [2]: Cursive::step()
/// [3]: Cursive::post_events()
pub fn process_events(&mut self) -> bool {
// Things are boring if nothing significant happened.
let mut boring = true;
// First, handle all available input
while let Some(event) = self.backend.poll_event() {
boring = false;
self.on_event(event);
if !self.running {
return true;
}
}
// Then, handle any available callback
while let Ok(cb) = self.cb_source.try_recv() {
boring = false;
cb(self);
if !self.running {
return true;
}
}
!boring
}
/// Performs the second half of `Self::step()`.
///
/// This is an advanced method for fine-tuned manual stepping;
/// you probably want [`run`][1] or [`step`][2].
///
/// You should call this after [`process_events`][3].
///
/// [1]: Cursive::run()
/// [2]: Cursive::step()
/// [3]: Cursive::process_events()
pub fn post_events(&mut self, received_something: bool) {
let boring = !received_something;
// How many times should we try if it's still boring?
// Total duration will be INPUT_POLL_DELAY_MS * repeats
// So effectively fps = 1000 / INPUT_POLL_DELAY_MS / repeats
if !boring
|| self
.fps
.map(|fps| 1000 / INPUT_POLL_DELAY_MS as u32 / fps.get())
.map(|repeats| self.boring_frame_count >= repeats)
.unwrap_or(false)
{
// We deserve to draw something!
if boring {
// We're only here because of a timeout.
self.on_event(Event::Refresh);
}
self.refresh();
}
if boring {
std::thread::sleep(Duration::from_millis(INPUT_POLL_DELAY_MS));
self.boring_frame_count += 1;
}
}
/// Refresh the screen with the current view tree state.
pub fn refresh(&mut self) {
self.boring_frame_count = 0;
// Do we need to redraw everytime?
// Probably, actually.
// TODO: Do we need to re-layout everytime?
self.layout();
// TODO: Do we need to redraw every view every time?
// (Is this getting repetitive? :p)
self.draw();
self.backend.refresh();
}
/// Stops the event loop.
pub fn quit(&mut self) {
self.running = false;
}
/// Does not do anything.
pub fn noop(&mut self) {
// foo
}
/// Return the name of the backend used.
///
/// Mostly used for debugging.
pub fn backend_name(&self) -> &str {
self.backend.name()
}
/// Dump the current state of the Cursive root.
///
/// *It will clear out this `Cursive` instance* and save everything, including:
/// * The view tree
/// * Callbacks
/// * Menubar
/// * User data
/// * Callback sink
///
/// After calling this, the cursive object will be as if newly created.
pub fn dump(&mut self) -> crate::Dump {
let (cb_sink, cb_source) = crossbeam_channel::unbounded();
let root = views::OnEventView::new(views::ScreensView::single_screen(
views::StackView::new(),
));
Dump {
cb_sink: std::mem::replace(&mut self.cb_sink, cb_sink),
cb_source: std::mem::replace(&mut self.cb_source, cb_source),
fps: self.fps.take(),
menubar: std::mem::take(&mut self.menubar),
root_view: std::mem::replace(&mut self.root, root),
theme: std::mem::take(&mut self.theme),
user_data: std::mem::replace(&mut self.user_data, Box::new(())),
}
}
/// Restores the state from a previous dump.
///
/// This will discard everything from this `Cursive` instance.
/// In particular:
/// * All current views will be dropped, replaced by the dump.
/// * All callbacks will be replaced.
/// * Menubar will be replaced.
/// * User Data will be replaced.
/// * The callback channel will be replaced - any previous call to
/// `cb_sink` on this instance will be disconnected.
pub fn restore(&mut self, dump: Dump) {
self.cb_sink = dump.cb_sink;
self.cb_source = dump.cb_source;
self.fps = dump.fps;
self.menubar = dump.menubar;
self.root = dump.root_view;
self.theme = dump.theme;
self.user_data = dump.user_data;
self.clear();
}
}
impl Drop for Cursive {
fn drop(&mut self) {
self.backend.finish();
}
}