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squeekboard/src/state.rs
2022-04-06 08:58:41 +00:00

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/* Copyright (C) 2021 Purism SPC
* SPDX-License-Identifier: GPL-3.0+
*/
/*! Application-wide state is stored here.
* It's driven by the loop defined in the loop module. */
use crate::animation;
use crate::imservice::{ ContentHint, ContentPurpose };
use crate::main::{ Commands, PanelCommand, PixelSize };
use crate::outputs;
use crate::outputs::{OutputId, OutputState};
use crate::util::Rational;
use std::cmp;
use std::collections::HashMap;
use std::time::Instant;
#[derive(Clone, Copy)]
pub enum Presence {
Present,
Missing,
}
#[derive(Clone)]
pub struct InputMethodDetails {
pub hint: ContentHint,
pub purpose: ContentPurpose,
}
#[derive(Clone)]
pub enum InputMethod {
Active(InputMethodDetails),
InactiveSince(Instant),
}
/// Incoming events.
/// This contains events that cause a change to the internal state.
#[derive(Clone)]
pub enum Event {
InputMethod(InputMethod),
Visibility(visibility::Event),
PhysicalKeyboard(Presence),
Output(outputs::Event),
/// Event triggered because a moment in time passed.
/// Use to animate state transitions.
/// The value is the ideal arrival time.
TimeoutReached(Instant),
}
impl From<InputMethod> for Event {
fn from(im: InputMethod) -> Self {
Self::InputMethod(im)
}
}
impl From<outputs::Event> for Event {
fn from(ev: outputs::Event) -> Self {
Self::Output(ev)
}
}
pub mod visibility {
#[derive(Clone)]
pub enum Event {
/// User requested the panel to show
ForceVisible,
/// The user requested the panel to go down
ForceHidden,
}
#[derive(Clone, PartialEq, Debug, Copy)]
pub enum State {
/// Last interaction was user forcing the panel to go visible
ForcedVisible,
/// Last interaction was user forcing the panel to hide
ForcedHidden,
/// Last interaction was the input method changing active state
NotForced,
}
}
/// The outwardly visible state.
#[derive(Clone)]
pub struct Outcome {
pub visibility: animation::Outcome,
pub im: InputMethod,
}
impl Outcome {
/// Returns the commands needed to apply changes as required by the new state.
/// This implementation doesn't actually take the old state into account,
/// instead issuing all the commands as needed to reach the new state.
/// The receivers of the commands bear the burden
/// of checking if the commands end up being no-ops.
pub fn get_commands_to_reach(&self, new_state: &Self) -> Commands {
let layout_hint_set = match new_state {
Outcome {
visibility: animation::Outcome::Visible{..},
im: InputMethod::Active(hints),
} => Some(hints.clone()),
Outcome {
visibility: animation::Outcome::Visible{..},
im: InputMethod::InactiveSince(_),
} => Some(InputMethodDetails {
hint: ContentHint::NONE,
purpose: ContentPurpose::Normal,
}),
Outcome {
visibility: animation::Outcome::Hidden,
..
} => None,
};
// FIXME: handle switching outputs
let (dbus_visible_set, panel_visibility) = match new_state.visibility {
animation::Outcome::Visible{output, height}
=> (Some(true), Some(PanelCommand::Show{output, height})),
animation::Outcome::Hidden => (Some(false), Some(PanelCommand::Hide)),
};
Commands {
panel_visibility,
layout_hint_set,
dbus_visible_set,
}
}
}
/// The actual logic of the program.
/// At this moment, limited to calculating visibility and IM hints.
///
/// It keeps the panel visible for a short time period after each hide request.
/// This prevents flickering on quick successive enable/disable events.
/// It does not treat user-driven hiding in a special way.
///
/// This is the "functional core".
/// All state changes return the next state and the optimal time for the next check.
///
/// This state tracker can be driven by any event loop.
#[derive(Clone)]
pub struct Application {
pub im: InputMethod,
pub visibility_override: visibility::State,
pub physical_keyboard: Presence,
/// The output on which the panel should appear.
/// This is stored as part of the state
/// because it's not clear how to derive the output from the rest of the state.
/// It should probably follow the focused input,
/// but not sure about being allowed on non-touch displays.
pub preferred_output: Option<OutputId>,
pub outputs: HashMap<OutputId, OutputState>,
}
impl Application {
/// A conservative default, ignoring the actual state of things.
/// It will initially show the keyboard for a blink.
// The ignorance might actually be desired,
// as it allows for startup without waiting for a system check.
// The downside is that adding actual state should not cause transitions.
// Another acceptable alternative is to allow explicitly uninitialized parts.
pub fn new(now: Instant) -> Self {
Self {
im: InputMethod::InactiveSince(now),
visibility_override: visibility::State::NotForced,
physical_keyboard: Presence::Missing,
preferred_output: None,
outputs: Default::default(),
}
}
pub fn apply_event(self, event: Event, _now: Instant) -> Self {
match event {
Event::TimeoutReached(_) => self,
Event::Visibility(visibility) => Self {
visibility_override: match visibility {
visibility::Event::ForceHidden => visibility::State::ForcedHidden,
visibility::Event::ForceVisible => visibility::State::ForcedVisible,
},
..self
},
Event::PhysicalKeyboard(presence) => Self {
physical_keyboard: presence,
..self
},
Event::Output(outputs::Event { output, change }) => {
let mut app = self;
match change {
outputs::ChangeType::Altered(state) => {
app.outputs.insert(output, state);
app.preferred_output = app.preferred_output.or(Some(output));
},
outputs::ChangeType::Removed => {
app.outputs.remove(&output);
if app.preferred_output == Some(output) {
// There's currently no policy to choose one output over another,
// so just take whichever comes first.
app.preferred_output = app.outputs.keys().next().map(|output| *output);
}
},
};
app
},
Event::InputMethod(new_im) => match (self.im.clone(), new_im) {
(InputMethod::Active(_old), InputMethod::Active(new_im))
=> Self {
im: InputMethod::Active(new_im),
..self
},
// For changes in active state, remove user's visibility override.
// Both cases spelled out explicitly, rather than by the wildcard,
// to not lose the notion that it's the opposition that matters
(InputMethod::InactiveSince(_old), InputMethod::Active(new_im))
=> Self {
im: InputMethod::Active(new_im),
visibility_override: visibility::State::NotForced,
..self
},
(InputMethod::Active(_old), InputMethod::InactiveSince(since))
=> Self {
im: InputMethod::InactiveSince(since),
visibility_override: visibility::State::NotForced,
..self
},
// This is a weird case, there's no need to update an inactive state.
// But it's not wrong, just superfluous.
(InputMethod::InactiveSince(old), InputMethod::InactiveSince(_new))
=> Self {
// New is going to be newer than old, so it can be ignored.
// It was already inactive at that moment.
im: InputMethod::InactiveSince(old),
..self
},
}
}
}
fn get_preferred_height(output: &OutputState) -> Option<PixelSize> {
output.get_pixel_size()
.map(|px_size| {
let height = {
if px_size.width > px_size.height {
px_size.width / 5
} else {
let abstract_width
= PixelSize {
scale_factor: output.scale as u32,
pixels: px_size.width,
}
.as_scaled_ceiling();
if (abstract_width < 540) && (px_size.width > 0) {
px_size.width * 7 / 12 // to match 360×210
} else {
// Here we switch to wide layout, less height needed
px_size.width * 7 / 22
}
}
};
PixelSize {
scale_factor: output.scale as u32,
pixels: cmp::min(height, px_size.height / 2),
}
})
}
pub fn get_outcome(&self, now: Instant) -> Outcome {
// FIXME: include physical keyboard presence
Outcome {
visibility: match self.preferred_output {
None => animation::Outcome::Hidden,
Some(output) => {
// Hoping that this will get optimized out on branches not using `visible`.
let height = Self::get_preferred_height(self.outputs.get(&output).unwrap())
.unwrap_or(PixelSize{pixels: 0, scale_factor: 1});
// TODO: Instead of setting size to 0 when the output is invalid,
// simply go invisible.
let visible = animation::Outcome::Visible{ output, height };
match (self.physical_keyboard, self.visibility_override) {
(_, visibility::State::ForcedHidden) => animation::Outcome::Hidden,
(_, visibility::State::ForcedVisible) => visible,
(Presence::Present, visibility::State::NotForced) => animation::Outcome::Hidden,
(Presence::Missing, visibility::State::NotForced) => match self.im {
InputMethod::Active(_) => visible,
InputMethod::InactiveSince(since) => {
if now < since + animation::HIDING_TIMEOUT { visible }
else { animation::Outcome::Hidden }
},
},
}
}
},
im: self.im.clone(),
}
}
/// Returns the next time to update the outcome.
pub fn get_next_wake(&self, now: Instant) -> Option<Instant> {
match self {
Self {
visibility_override: visibility::State::NotForced,
im: InputMethod::InactiveSince(since),
..
} => {
let anim_end = *since + animation::HIDING_TIMEOUT;
if now < anim_end { Some(anim_end) }
else { None }
}
_ => None,
}
}
}
#[cfg(test)]
pub mod test {
use super::*;
use crate::outputs::c::WlOutput;
use std::time::Duration;
fn imdetails_new() -> InputMethodDetails {
InputMethodDetails {
purpose: ContentPurpose::Normal,
hint: ContentHint::NONE,
}
}
fn fake_output_id(id: usize) -> OutputId {
OutputId(unsafe {
std::mem::transmute::<_, WlOutput>(id)
})
}
pub fn application_with_fake_output(start: Instant) -> Application {
let id = fake_output_id(1);
let mut outputs = HashMap::new();
outputs.insert(
id,
OutputState {
current_mode: None,
geometry: None,
scale: 1,
},
);
Application {
preferred_output: Some(id),
outputs,
..Application::new(start)
}
}
/// Test the original delay scenario: no flicker on quick switches.
#[test]
fn avoid_hide() {
let start = Instant::now(); // doesn't matter when. It would be better to have a reproducible value though
let mut now = start;
let state = Application {
im: InputMethod::Active(imdetails_new()),
physical_keyboard: Presence::Missing,
visibility_override: visibility::State::NotForced,
..application_with_fake_output(start)
};
let state = state.apply_event(Event::InputMethod(InputMethod::InactiveSince(now)), now);
// Check 100ms at 1ms intervals. It should remain visible.
for _i in 0..100 {
now += Duration::from_millis(1);
assert_matches!(
state.get_outcome(now).visibility,
animation::Outcome::Visible{..},
"Hidden when it should remain visible: {:?}",
now.saturating_duration_since(start),
)
}
let state = state.apply_event(Event::InputMethod(InputMethod::Active(imdetails_new())), now);
assert_matches!(state.get_outcome(now).visibility, animation::Outcome::Visible{..});
}
/// Make sure that hiding works when input method goes away
#[test]
fn hide() {
let start = Instant::now(); // doesn't matter when. It would be better to have a reproducible value though
let mut now = start;
let state = Application {
im: InputMethod::Active(imdetails_new()),
physical_keyboard: Presence::Missing,
visibility_override: visibility::State::NotForced,
..application_with_fake_output(start)
};
let state = state.apply_event(Event::InputMethod(InputMethod::InactiveSince(now)), now);
while let animation::Outcome::Visible{..} = state.get_outcome(now).visibility {
now += Duration::from_millis(1);
assert!(
now < start + Duration::from_millis(250),
"Hiding too slow: {:?}",
now.saturating_duration_since(start),
);
}
}
/// Check against the false showing bug.
/// Expectation: it will get hidden and not appear again
#[test]
fn false_show() {
let start = Instant::now(); // doesn't matter when. It would be better to have a reproducible value though
let mut now = start;
let state = Application {
im: InputMethod::Active(imdetails_new()),
physical_keyboard: Presence::Missing,
visibility_override: visibility::State::NotForced,
..application_with_fake_output(start)
};
// This reflects the sequence from Wayland:
// disable, disable, enable, disable
// all in a single batch.
let state = state.apply_event(Event::InputMethod(InputMethod::InactiveSince(now)), now);
let state = state.apply_event(Event::InputMethod(InputMethod::InactiveSince(now)), now);
let state = state.apply_event(Event::InputMethod(InputMethod::Active(imdetails_new())), now);
let state = state.apply_event(Event::InputMethod(InputMethod::InactiveSince(now)), now);
while let animation::Outcome::Visible{..} = state.get_outcome(now).visibility {
now += Duration::from_millis(1);
assert!(
now < start + Duration::from_millis(250),
"Still not hidden: {:?}",
now.saturating_duration_since(start),
);
}
// One second without appearing again
for _i in 0..1000 {
now += Duration::from_millis(1);
assert_eq!(
state.get_outcome(now).visibility,
animation::Outcome::Hidden,
"Appeared unnecessarily: {:?}",
now.saturating_duration_since(start),
);
}
}
#[test]
fn force_visible() {
let start = Instant::now(); // doesn't matter when. It would be better to have a reproducible value though
let mut now = start;
let state = Application {
im: InputMethod::InactiveSince(now),
physical_keyboard: Presence::Missing,
visibility_override: visibility::State::NotForced,
..application_with_fake_output(start)
};
now += Duration::from_secs(1);
let state = state.apply_event(Event::Visibility(visibility::Event::ForceVisible), now);
assert_matches!(
state.get_outcome(now).visibility,
animation::Outcome::Visible{..},
"Failed to show: {:?}",
now.saturating_duration_since(start),
);
now += Duration::from_secs(1);
let state = state.apply_event(Event::InputMethod(InputMethod::Active(imdetails_new())), now);
now += Duration::from_secs(1);
let state = state.apply_event(Event::InputMethod(InputMethod::InactiveSince(now)), now);
now += Duration::from_secs(1);
assert_eq!(
state.get_outcome(now).visibility,
animation::Outcome::Hidden,
"Failed to release forced visibility: {:?}",
now.saturating_duration_since(start),
);
}
#[test]
fn keyboard_present() {
let start = Instant::now(); // doesn't matter when. It would be better to have a reproducible value though
let mut now = start;
let state = Application {
im: InputMethod::Active(imdetails_new()),
physical_keyboard: Presence::Missing,
visibility_override: visibility::State::NotForced,
..application_with_fake_output(start)
};
now += Duration::from_secs(1);
let state = state.apply_event(Event::PhysicalKeyboard(Presence::Present), now);
assert_eq!(
state.get_outcome(now).visibility,
animation::Outcome::Hidden,
"Failed to hide: {:?}",
now.saturating_duration_since(start),
);
now += Duration::from_secs(1);
let state = state.apply_event(Event::InputMethod(InputMethod::InactiveSince(now)), now);
now += Duration::from_secs(1);
let state = state.apply_event(Event::InputMethod(InputMethod::Active(imdetails_new())), now);
assert_eq!(
state.get_outcome(now).visibility,
animation::Outcome::Hidden,
"Failed to remain hidden: {:?}",
now.saturating_duration_since(start),
);
now += Duration::from_secs(1);
let state = state.apply_event(Event::PhysicalKeyboard(Presence::Missing), now);
assert_matches!(
state.get_outcome(now).visibility,
animation::Outcome::Visible{..},
"Failed to appear: {:?}",
now.saturating_duration_since(start),
);
}
}