Files
wayvr/wgui/src/layout.rs
T
2025-12-26 23:22:17 +01:00

859 lines
21 KiB
Rust

use std::{
cell::{RefCell, RefMut},
collections::{HashMap, HashSet, VecDeque},
io::Write,
rc::{Rc, Weak},
};
use crate::{
animation::Animations,
components::{Component, RefreshData},
drawing::{self, ANSI_BOLD_CODE, ANSI_RESET_CODE, Boundary, push_scissor_stack, push_transform_stack},
event::{self, CallbackDataCommon, EventAlterables},
globals::WguiGlobals,
widget::{self, EventParams, EventResult, WidgetObj, WidgetState, WidgetStateFlags, div::WidgetDiv},
};
use anyhow::Context;
use glam::{Vec2, vec2};
use slotmap::{HopSlotMap, SecondaryMap, new_key_type};
use taffy::{NodeId, TaffyTree, TraversePartialTree};
new_key_type! {
pub struct WidgetID;
}
#[derive(Clone)]
pub struct Widget(Rc<RefCell<WidgetState>>);
pub struct WeakWidget(Weak<RefCell<WidgetState>>);
impl Widget {
pub fn new(widget_state: WidgetState) -> Self {
Self(Rc::new(RefCell::new(widget_state)))
}
pub fn get_as<T: 'static>(&self) -> Option<RefMut<'_, T>> {
RefMut::filter_map(self.0.borrow_mut(), |w| w.obj.get_as_mut::<T>()).ok()
}
pub fn cast<T: 'static>(&self) -> anyhow::Result<RefMut<'_, T>> {
self.get_as().context("Widget cast failed")
}
pub fn downgrade(&self) -> WeakWidget {
WeakWidget(Rc::downgrade(&self.0))
}
pub fn state(&self) -> RefMut<'_, WidgetState> {
self.0.borrow_mut()
}
}
impl WeakWidget {
pub fn upgrade(&self) -> Option<Widget> {
self.0.upgrade().map(Widget)
}
}
pub struct WidgetMap(HopSlotMap<WidgetID, Widget>);
pub type WidgetNodeMap = SecondaryMap<WidgetID, taffy::NodeId>;
#[derive(Clone)]
pub struct WidgetPair {
pub id: WidgetID,
pub widget: Widget,
}
impl WidgetMap {
fn new() -> Self {
Self(HopSlotMap::with_key())
}
pub fn get_as<T: 'static>(&self, handle: WidgetID) -> Option<RefMut<'_, T>> {
self.0.get(handle)?.get_as::<T>()
}
pub fn get(&self, handle: WidgetID) -> Option<&Widget> {
self.0.get(handle)
}
pub fn insert(&mut self, obj: Widget) -> WidgetID {
self
.0
.try_insert_with_key::<_, ()>(|widget_id| {
obj.state().obj.set_id(widget_id);
Ok(obj)
})
.unwrap()
}
pub fn remove_single(&mut self, handle: WidgetID) {
self.0.remove(handle);
}
// cast to specific widget type, does nothing if widget ID is expired or the type is wrong
pub fn call<WIDGET, FUNC>(&self, widget_id: WidgetID, func: FUNC)
where
WIDGET: WidgetObj,
FUNC: FnOnce(&mut WIDGET),
{
let Some(widget) = self.get(widget_id) else {
debug_assert!(false);
return;
};
if let Some(mut casted) = widget.get_as::<WIDGET>() {
func(&mut casted);
}
}
}
pub struct LayoutState {
pub globals: WguiGlobals,
pub widgets: WidgetMap,
pub nodes: WidgetNodeMap,
pub tree: taffy::tree::TaffyTree<WidgetID>,
}
pub struct ModifyLayoutStateData<'a> {
pub layout: &'a mut Layout,
}
pub type ModifyLayoutStateFunc = Box<dyn Fn(ModifyLayoutStateData) -> anyhow::Result<()>>;
pub enum LayoutTask {
RemoveWidget(WidgetID),
ModifyLayoutState(ModifyLayoutStateFunc),
}
#[derive(Clone)]
pub struct LayoutTasks(pub Rc<RefCell<VecDeque<LayoutTask>>>);
impl LayoutTasks {
fn new() -> Self {
Self(Rc::new(RefCell::new(VecDeque::new())))
}
pub fn push(&self, task: LayoutTask) {
self.0.borrow_mut().push_back(task);
}
}
pub struct Layout {
pub state: LayoutState,
pub tasks: LayoutTasks,
components_to_refresh_once: HashSet<Component>,
registered_components_to_refresh: HashMap<taffy::NodeId, Component>,
pub widgets_to_tick: Vec<WidgetID>,
// *Main root*
// contains content_root_widget and topmost widgets
pub tree_root_widget: WidgetID,
pub tree_root_node: taffy::NodeId,
// *Main topmost widget*
// main topmost widget, always present, parent of `tree_root_widget`
pub content_root_widget: WidgetID,
pub content_root_node: taffy::NodeId,
pub prev_size: Vec2,
pub content_size: Vec2,
pub needs_redraw: bool,
pub haptics_triggered: bool,
pub animations: Animations,
}
#[derive(Default)]
pub struct LayoutParams {
pub resize_to_parent: bool,
}
fn add_child_internal(
tree: &mut taffy::TaffyTree<WidgetID>,
widgets: &mut WidgetMap,
nodes: &mut WidgetNodeMap,
parent_node: Option<taffy::NodeId>,
widget_state: WidgetState,
style: taffy::Style,
) -> anyhow::Result<(WidgetPair, taffy::NodeId)> {
let new_widget = Widget::new(widget_state);
let child_id = widgets.insert(new_widget.clone());
let child_node = tree.new_leaf_with_context(style, child_id)?;
if let Some(parent_node) = parent_node {
tree.add_child(parent_node, child_node)?;
}
nodes.insert(child_id, child_node);
Ok((
WidgetPair {
id: child_id,
widget: new_widget,
},
child_node,
))
}
pub struct LayoutCommon<'a> {
alterables: EventAlterables,
pub layout: &'a mut Layout,
}
impl LayoutCommon<'_> {
pub const fn common(&mut self) -> CallbackDataCommon<'_> {
CallbackDataCommon {
alterables: &mut self.alterables,
state: &self.layout.state,
}
}
pub fn finish(self) -> anyhow::Result<()> {
self.layout.process_alterables(self.alterables)?;
Ok(())
}
}
impl Layout {
// helper function
pub fn start_common(&mut self) -> LayoutCommon<'_> {
LayoutCommon {
alterables: EventAlterables::default(),
layout: self,
}
}
pub fn add_topmost_child(
&mut self,
widget: WidgetState,
style: taffy::Style,
) -> anyhow::Result<(WidgetPair, taffy::NodeId)> {
self.mark_redraw();
add_child_internal(
&mut self.state.tree,
&mut self.state.widgets,
&mut self.state.nodes,
Some(self.tree_root_node),
widget,
style,
)
}
pub fn add_child(
&mut self,
parent_widget_id: WidgetID,
widget: WidgetState,
style: taffy::Style,
) -> anyhow::Result<(WidgetPair, taffy::NodeId)> {
let parent_node = *self.state.nodes.get(parent_widget_id).unwrap();
self.mark_redraw();
add_child_internal(
&mut self.state.tree,
&mut self.state.widgets,
&mut self.state.nodes,
Some(parent_node),
widget,
style,
)
}
fn collect_children_ids_recursive(&self, widget_id: WidgetID, out: &mut Vec<(WidgetID, taffy::NodeId)>) {
let Some(node_id) = self.state.nodes.get(widget_id) else {
return;
};
for child_id in self.state.tree.child_ids(*node_id) {
let child_widget_id = self.state.tree.get_node_context(child_id).unwrap();
out.push((*child_widget_id, child_id));
self.collect_children_ids_recursive(*child_widget_id, out);
}
}
fn remove_widget_single(&mut self, widget_id: WidgetID, node_id: Option<taffy::NodeId>) {
self.state.widgets.remove_single(widget_id);
self.state.nodes.remove(widget_id);
if let Some(node_id) = node_id {
self.registered_components_to_refresh.remove(&node_id);
let _ = self.state.tree.remove(node_id);
}
}
// removes all children of a specific widget
pub fn remove_children(&mut self, widget_id: WidgetID) {
let mut ids = Vec::new();
self.collect_children_ids_recursive(widget_id, &mut ids);
if !ids.is_empty() {
self.mark_redraw();
}
for (widget_id, node_id) in ids {
self.remove_widget_single(widget_id, Some(node_id));
}
}
// remove widget and its children, recursively
pub fn remove_widget(&mut self, widget_id: WidgetID) {
self.remove_children(widget_id);
let node_id = self.state.nodes.get(widget_id);
self.remove_widget_single(widget_id, node_id.copied());
self.mark_redraw();
}
pub const fn mark_redraw(&mut self) {
self.needs_redraw = true;
}
fn process_pending_components(&mut self, alterables: &mut EventAlterables) {
for comp in &self.components_to_refresh_once {
let mut common = CallbackDataCommon {
state: &self.state,
alterables,
};
comp.0.refresh(&mut RefreshData { common: &mut common });
}
self.components_to_refresh_once.clear();
}
fn process_pending_widget_ticks(&mut self, alterables: &mut EventAlterables) {
for widget_id in &self.widgets_to_tick {
let Some(widget) = self.state.widgets.get(*widget_id) else {
continue;
};
widget.state().tick(*widget_id, alterables);
}
self.widgets_to_tick.clear();
}
// call ComponentTrait::refresh() *once* in the next tick
pub fn defer_component_refresh(&mut self, component: Component) {
self.components_to_refresh_once.insert(component);
}
// call ComponentTrait::refresh() *every time time* the layout is dirty
pub fn register_component_refresh(&mut self, component: Component) {
let widget_id = component.0.base().get_id();
let Some(node_id) = self.state.nodes.get(widget_id) else {
debug_assert!(false);
return;
};
self.registered_components_to_refresh.insert(*node_id, component);
}
/// Convenience function to avoid repeated `WidgetID` → `WidgetState` lookups.
pub fn add_event_listener<U1: 'static, U2: 'static>(
&self,
widget_id: WidgetID,
kind: event::EventListenerKind,
callback: event::EventCallback<U1, U2>,
) -> Option<event::EventListenerID> {
Some(
self
.state
.widgets
.get(widget_id)?
.state()
.event_listeners
.register(kind, callback),
)
}
fn push_event_children<'a, U1: 'static, U2: 'static>(
&self,
parent_node_id: taffy::NodeId,
event: &event::Event,
event_result: &mut EventResult,
alterables: &mut EventAlterables,
user_data: &mut (&'a mut U1, &'a mut U2),
) -> anyhow::Result<()> {
let count = self.state.tree.child_count(parent_node_id);
let mut iter = |idx: usize| -> anyhow::Result<bool> {
let child_id = self.state.tree.get_child_id(parent_node_id, idx);
self.push_event_widget(child_id, event, event_result, alterables, user_data)?;
Ok(!event_result.can_propagate())
};
// reverse iter
for idx in (0..count).rev() {
if iter(idx)? {
break;
}
}
Ok(())
}
fn push_event_widget<'a, U1: 'static, U2: 'static>(
&self,
node_id: taffy::NodeId,
event: &event::Event,
event_result: &mut EventResult,
alterables: &mut EventAlterables,
user_data: &mut (&'a mut U1, &'a mut U2),
) -> anyhow::Result<()> {
let l = self.state.tree.layout(node_id)?;
let Some(widget_id) = self.state.tree.get_node_context(node_id).copied() else {
anyhow::bail!("invalid widget ID");
};
let style = self.state.tree.style(node_id)?;
if style.display == taffy::Display::None {
return Ok(());
}
let Some(widget) = self.state.widgets.get(widget_id) else {
debug_assert!(false);
anyhow::bail!("invalid widget");
};
let mut widget = widget.0.borrow_mut();
let (scroll_shift, info) = match widget::get_scrollbar_info(l) {
Some(info) => (widget.get_scroll_shift_raw(&info, l), Some(info)),
None => (Vec2::default(), None),
};
// see drawing.rs draw_widget too
push_transform_stack(&mut alterables.transform_stack, l, scroll_shift, &widget);
widget.data.cached_absolute_boundary = drawing::Boundary::construct_absolute(&alterables.transform_stack);
let scissor_pushed = push_scissor_stack(
&mut alterables.transform_stack,
&mut alterables.scissor_stack,
scroll_shift,
&info,
style,
);
// check children first
self.push_event_children(node_id, event, event_result, alterables, user_data)?;
if event_result.can_propagate() {
let mut params = EventParams {
state: &self.state,
layout: l,
alterables,
node_id,
style,
};
widget.process_event(widget_id, node_id, event, event_result, user_data, &mut params)?;
}
if scissor_pushed {
alterables.scissor_stack.pop();
}
alterables.transform_stack.pop();
Ok(())
}
pub const fn check_toggle_needs_redraw(&mut self) -> bool {
if self.needs_redraw {
self.needs_redraw = false;
true
} else {
false
}
}
pub const fn check_toggle_haptics_triggered(&mut self) -> bool {
if self.haptics_triggered {
self.haptics_triggered = false;
true
} else {
false
}
}
pub fn push_event<U1: 'static, U2: 'static>(
&mut self,
event: &event::Event,
user1: &mut U1,
user2: &mut U2,
) -> anyhow::Result<EventResult> {
let mut alterables = EventAlterables::default();
let mut event_result = EventResult::NoHit;
self.push_event_widget(
self.tree_root_node,
event,
&mut event_result,
&mut alterables,
&mut (user1, user2),
)?;
self.process_alterables(alterables)?;
Ok(event_result)
}
pub fn new(globals: WguiGlobals, params: &LayoutParams) -> anyhow::Result<Self> {
let mut state = LayoutState {
tree: TaffyTree::new(),
widgets: WidgetMap::new(),
nodes: WidgetNodeMap::default(),
globals,
};
let size = if params.resize_to_parent {
taffy::Size::percent(1.0)
} else {
taffy::Size::auto()
};
let (tree_root_widget, tree_root_node) = add_child_internal(
&mut state.tree,
&mut state.widgets,
&mut state.nodes,
None, // no parent
WidgetState {
flags: WidgetStateFlags {
interactable: false,
..Default::default()
},
..WidgetDiv::create()
},
taffy::Style {
size,
..Default::default()
},
)?;
let (content_root_widget, content_root_node) = add_child_internal(
&mut state.tree,
&mut state.widgets,
&mut state.nodes,
Some(tree_root_node),
WidgetState {
flags: WidgetStateFlags {
interactable: false,
..Default::default()
},
..WidgetDiv::create()
},
taffy::Style {
size,
..Default::default()
},
)?;
Ok(Self {
state,
prev_size: Vec2::default(),
content_size: Vec2::default(),
tree_root_node,
tree_root_widget: tree_root_widget.id,
content_root_node,
content_root_widget: content_root_widget.id,
needs_redraw: true,
haptics_triggered: false,
animations: Animations::default(),
components_to_refresh_once: HashSet::new(),
registered_components_to_refresh: HashMap::new(),
widgets_to_tick: Vec::new(),
tasks: LayoutTasks::new(),
})
}
fn refresh_recursively(&self, node_id: taffy::NodeId, to_refresh: &mut Vec<Component>) {
// skip refreshing clean nodes
if !self.state.tree.dirty(node_id).unwrap() {
return;
}
if let Some(component) = self.registered_components_to_refresh.get(&node_id) {
to_refresh.push(component.clone());
}
for child_id in self.state.tree.child_ids(node_id) {
self.refresh_recursively(child_id, to_refresh);
}
}
fn try_recompute_layout(&mut self, size: Vec2) -> anyhow::Result<()> {
if !self.state.tree.dirty(self.tree_root_node)? && self.prev_size == size {
// Nothing to do
return Ok(());
}
log::trace!("re-computing layout, size {}x{}", size.x, size.y);
self.mark_redraw();
self.prev_size = size;
let mut to_refresh = Vec::<Component>::new();
self.refresh_recursively(self.tree_root_node, &mut to_refresh);
if !to_refresh.is_empty() {
log::trace!("refreshing {} registered components", to_refresh.len());
for c in &to_refresh {
self.components_to_refresh_once.insert(c.clone());
}
}
let globals = self.state.globals.get();
self.state.tree.compute_layout_with_measure(
self.tree_root_node,
taffy::Size {
width: taffy::AvailableSpace::Definite(size.x),
height: taffy::AvailableSpace::Definite(size.y),
},
|known_dimensions, available_space, _node_id, node_context, _style| {
if let taffy::Size {
width: Some(width),
height: Some(height),
} = known_dimensions
{
return taffy::Size { width, height };
}
match node_context {
None => taffy::Size::ZERO,
Some(h) => {
if let Some(w) = self.state.widgets.get(*h) {
w.0
.borrow_mut()
.obj
.measure(&globals, known_dimensions, available_space)
} else {
taffy::Size::ZERO
}
}
}
},
)?;
let root_size = self.state.tree.layout(self.tree_root_node).unwrap().size;
if self.content_size.x != root_size.width || self.content_size.y != root_size.height {
log::debug!(
"content size changed: {:.0}x{:.0} → {:.0}x{:.0}",
self.content_size.x,
self.content_size.y,
root_size.width,
root_size.height
);
}
self.content_size = vec2(root_size.width, root_size.height);
Ok(())
}
pub fn update(&mut self, size: Vec2, timestep_alpha: f32) -> anyhow::Result<()> {
let mut alterables = EventAlterables::default();
self.animations.process(&self.state, &mut alterables, timestep_alpha);
self.process_alterables(alterables)?;
self.try_recompute_layout(size)?;
Ok(())
}
pub fn tick(&mut self) -> anyhow::Result<()> {
let mut alterables = EventAlterables::default();
self.animations.tick(&self.state, &mut alterables);
self.process_pending_components(&mut alterables);
self.process_pending_widget_ticks(&mut alterables);
self.process_alterables(alterables)?;
Ok(())
}
pub fn process_tasks(&mut self) -> anyhow::Result<()> {
let tasks = self.tasks.clone();
let mut tasks = tasks.0.borrow_mut();
while let Some(task) = tasks.pop_front() {
match task {
LayoutTask::RemoveWidget(widget_id) => {
self.remove_widget(widget_id);
}
LayoutTask::ModifyLayoutState(callback) => {
(*callback)(ModifyLayoutStateData { layout: self })?;
}
}
}
Ok(())
}
pub fn process_alterables(&mut self, alterables: EventAlterables) -> anyhow::Result<()> {
for task in alterables.tasks {
self.tasks.push(task);
}
self.process_tasks()?;
for dirty_widget_id in alterables.dirty_widgets {
if let Some(dirty_node_id) = self.state.nodes.get(dirty_widget_id) {
self.state.tree.mark_dirty(*dirty_node_id)?;
}
}
if alterables.needs_redraw {
self.mark_redraw();
}
if alterables.trigger_haptics {
self.haptics_triggered = true;
}
if !alterables.animations.is_empty() {
self.mark_redraw();
for anim in alterables.animations {
self.animations.add(anim);
}
}
if !alterables.widgets_to_tick.is_empty() {
for widget_id in &alterables.widgets_to_tick {
self.widgets_to_tick.push(*widget_id);
}
}
for (widget_id, style_request) in alterables.style_set_requests {
let Some(node_id) = self.state.nodes.get(widget_id) else {
continue;
};
// taffy requires us to copy this whole 536-byte style struct.
// we can't get `&mut Style` directly from taffy unfortunately
let mut cur_style = self.state.tree.style(*node_id).unwrap().clone() /* always safe */;
match style_request {
event::StyleSetRequest::Display(display) => {
// refresh the component in case if visibility/display mode has changed
if cur_style.display != display
&& let Some(component) = self.registered_components_to_refresh.get(node_id)
{
self.components_to_refresh_once.insert(component.clone());
}
cur_style.display = display;
}
event::StyleSetRequest::Margin(margin) => {
cur_style.margin = margin;
}
event::StyleSetRequest::Width(val) => {
cur_style.size.width = val;
}
event::StyleSetRequest::Height(val) => {
cur_style.size.height = val;
}
}
if let Err(e) = self.state.tree.set_style(*node_id, cur_style) {
log::error!("failed to set style for taffy widget ID {node_id:?}: {e:?}");
}
}
Ok(())
}
pub fn print_tree(&self) {
let mut buf = Vec::<u8>::new();
self.print_tree_recur(&mut buf, 0, self.tree_root_node);
let str = format!(
"\n=== tree ===\n[widget type] [WidgetID] [taffy NodeID] [other data]\n{}",
unsafe { str::from_utf8_unchecked(&buf) }
);
std::io::stdout().write_all(str.as_bytes()).unwrap();
}
fn print_tree_recur(&self, buf: &mut Vec<u8>, depth: u32, node_id: taffy::NodeId) {
// indent
for _ in 0..depth {
buf.push(b'|');
buf.push(b' ');
}
let widget_id = self.state.tree.get_node_context(node_id).unwrap();
let layout = self.state.tree.layout(node_id).unwrap();
let widget = self.state.widgets.get(*widget_id).unwrap();
let state = widget.state();
let type_color = match state.obj.get_type() {
widget::WidgetType::Div => drawing::Color::new(1.0, 1.0, 1.0, 1.0),
widget::WidgetType::Label => drawing::Color::new(0.4, 1.0, 0.0, 1.0),
widget::WidgetType::Sprite => drawing::Color::new(0.0, 0.8, 1.0, 1.0),
widget::WidgetType::Rectangle => drawing::Color::new(1.0, 0.5, 0.2, 1.0),
};
let line = format!(
"{}{}{}{} 0x{:x?} 0x{:x?}: [pos: {}x{}][size: {}x{}]{}\n",
ANSI_BOLD_CODE,
type_color.debug_ansi_format(),
state.obj.get_type().as_str(),
ANSI_RESET_CODE,
state.obj.get_id().0.as_ffi(),
u64::from(node_id),
layout.location.x,
layout.location.y,
layout.content_size.width,
layout.content_size.height,
state.obj.debug_print()
);
buf.append(&mut line.into_bytes());
for child_id in self.state.tree.child_ids(node_id) {
self.print_tree_recur(buf, depth + 1, child_id);
}
}
}
impl LayoutState {
pub fn get_node_boundary(&self, id: NodeId) -> Boundary {
let Ok(layout) = self.tree.layout(id) else {
return Boundary::default();
};
Boundary {
pos: Vec2::new(layout.location.x, layout.location.y),
size: Vec2::new(layout.size.width, layout.size.height),
}
}
pub fn get_node_size(&self, id: NodeId) -> Vec2 {
let Ok(layout) = self.tree.layout(id) else {
return Vec2::ZERO;
};
Vec2::new(layout.size.width, layout.size.height)
}
pub fn get_node_style(&self, id: NodeId) -> Option<&taffy::Style> {
let Ok(style) = self.tree.style(id) else {
return None;
};
Some(style)
}
pub fn get_widget_boundary(&self, id: WidgetID) -> Boundary {
let Some(node_id) = self.nodes.get(id) else {
return Boundary::default();
};
self.get_node_boundary(*node_id)
}
pub fn get_widget_size(&self, id: WidgetID) -> Vec2 {
let Some(node_id) = self.nodes.get(id) else {
return Vec2::ZERO;
};
self.get_node_size(*node_id)
}
pub fn get_widget_style(&self, id: WidgetID) -> Option<&taffy::Style> {
self.get_node_style(*self.nodes.get(id)?)
}
}