wayvr/wgui/src/widget/mod.rs

781 lines
21 KiB
Rust

use anyhow::Context;
use glam::{FloatExt, Vec2};
use taffy::{NodeId, TaffyTree};
use super::drawing::RenderPrimitive;
use crate::{
any::AnyTrait,
drawing::{self, PrimitiveExtent},
event::{
self, CallbackData, CallbackDataCommon, CallbackMetadata, DeviceBitmask, Event, EventAlterables,
EventListenerCollection,
EventListenerKind::{self, InternalStateChange, MouseLeave},
MouseWheelEvent,
},
globals::Globals,
layout::{Layout, LayoutState, WidgetID},
stack::{ScissorStack, TransformStack},
};
pub mod custom_draw;
pub mod div;
pub mod image;
pub mod label;
pub mod rectangle;
pub mod sprite;
pub mod util;
const SWIPE_START_THRESHOLD_UNITS: f32 = 16.0;
const KINETIC_VELOCITY_DAMPING: f32 = 0.92;
const KINETIC_VELOCITY_BRAKE: f32 = 0.85;
const RUBBERBANDING_DAMP: f32 = 0.8;
pub struct WidgetData {
hovered: DeviceBitmask,
pressed: DeviceBitmask,
scrolling_target: Vec2, // normalized, 0.0-1.0. Not used in case if overflow != scroll
scrolling_cur: Vec2, // normalized, used for smooth scrolling animation
scrolling_cur_prev: Vec2, // for motion interpolation while rendering between ticks
scrolling_velocity: Vec2,
press_down_start_mouse_pos: Option<Vec2>,
swipe_running: bool,
swipe_scroll_start: Vec2, // normalized, 0.0-1.0
pub transform: glam::Mat4,
pub cached_absolute_boundary: drawing::Boundary, // updated in Layout::push_event_widget
}
impl WidgetData {
pub const fn set_device_pressed(&mut self, device: DeviceBitmask, pressed: bool) -> bool {
let bit = 1 << device.0;
let state_changed;
if pressed {
state_changed = self.pressed.0 == 0;
self.pressed.0 |= bit;
} else {
state_changed = self.pressed.0 == bit;
self.pressed.0 &= !bit;
}
state_changed
}
pub const fn set_device_hovered(&mut self, device: DeviceBitmask, hovered: bool) -> bool {
let bit = 1 << device.0;
let state_changed;
if hovered {
state_changed = self.hovered.0 == 0;
self.hovered.0 |= bit;
} else {
state_changed = self.hovered.0 == bit;
self.hovered.0 &= !bit;
}
state_changed
}
pub const fn get_pressed(&self, device: DeviceBitmask) -> bool {
self.pressed.0 & (1 << device.0) != 0
}
pub const fn get_hovered(&self, device: DeviceBitmask) -> bool {
self.hovered.0 & (1 << device.0) != 0
}
pub const fn is_pressed(&self) -> bool {
self.pressed.0 != 0
}
pub const fn is_hovered(&self) -> bool {
self.hovered.0 != 0
}
}
pub struct WidgetStateFlags {
pub interactable: bool,
// consume any incoming mouse event which is hovered at given widget
pub consume_mouse_events: bool,
// force a new render pass before rendering this widget
pub new_pass: bool,
}
impl Default for WidgetStateFlags {
fn default() -> Self {
Self {
interactable: true,
consume_mouse_events: false,
new_pass: false,
}
}
}
pub struct WidgetState {
pub data: WidgetData,
pub obj: Box<dyn WidgetObj>,
pub event_listeners: EventListenerCollection,
pub flags: WidgetStateFlags,
}
impl WidgetState {
pub fn get_data_obj_mut(&mut self) -> (&mut WidgetData, &mut dyn WidgetObj) {
let data = &mut self.data;
let obj = self.obj.as_mut();
(data, obj)
}
fn new(flags: WidgetStateFlags, obj: Box<dyn WidgetObj>) -> Self {
Self {
data: WidgetData {
hovered: DeviceBitmask(0),
pressed: DeviceBitmask(0),
scrolling_target: Vec2::default(),
scrolling_cur: Vec2::default(),
scrolling_cur_prev: Vec2::default(),
transform: glam::Mat4::IDENTITY,
cached_absolute_boundary: drawing::Boundary::default(),
press_down_start_mouse_pos: None,
swipe_running: false,
swipe_scroll_start: Vec2::default(),
scrolling_velocity: Vec2::default(),
},
obj,
event_listeners: EventListenerCollection::default(),
flags,
}
}
}
// global draw params
pub struct DrawState<'a> {
pub globals: &'a Globals,
pub layout: &'a Layout,
pub primitives: &'a mut Vec<RenderPrimitive>,
pub transform_stack: &'a mut TransformStack,
pub scissor_stack: &'a mut ScissorStack,
pub alterables: &'a mut EventAlterables,
}
// per-widget draw params
pub struct DrawParams<'a> {
pub node_id: taffy::NodeId,
pub style: &'a taffy::Style,
pub taffy_layout: &'a taffy::Layout,
}
pub enum WidgetType {
Div,
Label,
Sprite,
Rectangle,
CustomDraw,
}
impl WidgetType {
pub const fn as_str(&self) -> &str {
match self {
WidgetType::Div => "div",
WidgetType::Label => "label",
WidgetType::Sprite => "sprite",
WidgetType::Rectangle => "rectangle",
WidgetType::CustomDraw => "custom_draw",
}
}
}
pub trait WidgetObj: AnyTrait {
// every widget stores their of id for convenience reasons
fn get_id(&self) -> WidgetID;
fn set_id(&mut self, id: WidgetID); // always set at insertion
fn get_type(&self) -> WidgetType;
fn debug_print(&self, _globals: &Globals) -> String;
fn draw(&mut self, state: &mut DrawState, params: &DrawParams);
fn measure(
&mut self,
_globals: &Globals,
_known_dimensions: taffy::Size<Option<f32>>,
_available_space: taffy::Size<taffy::AvailableSpace>,
) -> taffy::Size<f32> {
taffy::Size::ZERO
}
}
pub struct EventParams<'a> {
pub node_id: taffy::NodeId,
pub style: &'a taffy::Style,
pub state: &'a LayoutState,
pub alterables: &'a mut EventAlterables,
pub taffy_layout: &'a taffy::Layout,
}
#[derive(Clone, Copy, Eq, PartialEq, PartialOrd)]
pub enum EventResult {
NoHit, // event was pushed but has not found a listener (yet)
Pass, // widget acknowledged it and allows the event to propagate further
Consumed, // widget triggered an action, do not propagate further
ConsumedExclusive, // same as `Consumed`, but with force-disabled swipe-scroll event (used in sliders for example)
}
impl EventResult {
#[must_use]
pub const fn can_propagate(&self) -> bool {
!matches!(self, EventResult::Consumed | EventResult::ConsumedExclusive)
}
#[must_use]
pub fn merge(self, other: Self) -> Self {
if self > other { self } else { other }
}
}
fn get_scroll_enabled(style: &taffy::Style) -> (bool, bool) {
(
style.overflow.x == taffy::Overflow::Scroll,
style.overflow.y == taffy::Overflow::Scroll,
)
}
const OVERFLOW_START_THRESHOLD_UNITS: f32 = 3.0; // don't show scrollbars for nearly non-scrollable lists
fn get_scroll_active_axis(style: &taffy::Style, taffy_layout: &taffy::Layout) -> (bool, bool) {
let (enabled_horiz, enabled_vert) = get_scroll_enabled(style);
if !enabled_horiz && !enabled_vert {
return (false, false);
}
let overflow = Vec2::new(taffy_layout.scroll_width(), taffy_layout.scroll_height());
(
overflow.x >= OVERFLOW_START_THRESHOLD_UNITS,
overflow.y >= OVERFLOW_START_THRESHOLD_UNITS,
)
}
pub struct ScrollbarInfo {
// total contents size of the currently scrolling widget
content_size: Vec2,
// 0.0 - 1.0
// 1.0: scrollbar handle not visible (inactive)
handle_size: Vec2,
}
pub fn get_scrollbar_info(taffy_layout: &taffy::Layout) -> Option<ScrollbarInfo> {
let overflow = Vec2::new(taffy_layout.scroll_width(), taffy_layout.scroll_height());
if overflow.x < OVERFLOW_START_THRESHOLD_UNITS && overflow.y < OVERFLOW_START_THRESHOLD_UNITS {
return None; // not overflowing
}
let content_size = Vec2::new(taffy_layout.content_size.width, taffy_layout.content_size.height);
let handle_size = 1.0 - (overflow / content_size);
Some(ScrollbarInfo {
content_size,
handle_size,
})
}
impl ScrollbarInfo {
fn get_potential_scroll_axis_multiplier(&self, taffy_layout: &taffy::Layout) -> Vec2 {
Vec2::new(
self.content_size.x - taffy_layout.content_box_width(),
self.content_size.y - taffy_layout.content_box_height(),
)
}
}
impl dyn WidgetObj {
pub fn get_as<T: 'static>(&self) -> Option<&T> {
let any = self.as_any();
any.downcast_ref::<T>()
}
pub fn cast<T: 'static>(&self) -> anyhow::Result<&T> {
self.get_as().context("cast failed")
}
pub fn get_as_mut<T: 'static>(&mut self) -> Option<&mut T> {
let any = self.as_any_mut();
any.downcast_mut::<T>()
}
pub fn cast_mut<T: 'static>(&mut self) -> anyhow::Result<&mut T> {
self.get_as_mut().context("cast failed")
}
}
struct InvokeData<'a, 'b, U1: 'static, U2: 'static> {
widget_id: WidgetID,
node_id: taffy::NodeId,
event_result: &'a mut EventResult,
user_data: &'a mut (&'b mut U1, &'b mut U2),
params: &'a mut EventParams<'a>,
}
#[must_use]
enum InvokeListenersResult {
NobodyListened,
AtLeastOneCalled,
}
impl WidgetState {
fn invoke_listeners<U1: 'static, U2: 'static>(
&mut self,
call_data: &mut InvokeData<'_, '_, U1, U2>,
kind: event::EventListenerKind,
metadata: CallbackMetadata,
) -> anyhow::Result<InvokeListenersResult> {
let mut data = CallbackData {
obj: self.obj.as_mut(),
widget_data: &mut self.data,
widget_id: call_data.widget_id,
node_id: call_data.node_id,
metadata,
};
let mut common = CallbackDataCommon {
state: call_data.params.state,
alterables: call_data.params.alterables,
};
let mut res = InvokeListenersResult::NobodyListened;
for listener in self.event_listeners.iter_filtered::<U1, U2>(kind) {
let new_result = listener.call_with(&mut common, &mut data, call_data.user_data)?;
res = InvokeListenersResult::AtLeastOneCalled;
// Consider all listeners on this widget, even if we had a Consume.
// Store the highest value for return.
*call_data.event_result = call_data.event_result.merge(new_result);
}
Ok(res)
}
pub fn get_scroll_shift_smooth(&self, info: &ScrollbarInfo, l: &taffy::Layout, timestep_alpha: f32) -> (Vec2, bool) {
let currently_animating = self.data.scrolling_cur != self.data.scrolling_cur_prev;
let scrolling = self
.data
.scrolling_cur_prev
.lerp(self.data.scrolling_cur, timestep_alpha);
(
Vec2::new(
(info.content_size.x - l.content_box_width()) * scrolling.x,
(info.content_size.y - l.content_box_height()) * scrolling.y,
),
currently_animating,
)
}
pub fn get_scroll_shift_raw(&self, info: &ScrollbarInfo, l: &taffy::Layout) -> Vec2 {
Vec2::new(
(info.content_size.x - l.content_box_width()) * self.data.scrolling_target.x,
(info.content_size.y - l.content_box_height()) * self.data.scrolling_target.y,
)
}
pub fn draw_all(&mut self, state: &mut DrawState, params: &DrawParams) {
self.obj.draw(state, params);
}
pub fn tick(&mut self, this_widget_id: WidgetID, alterables: &mut EventAlterables) {
let scrolling_cur = &mut self.data.scrolling_cur;
let scrolling_cur_prev = &mut self.data.scrolling_cur_prev;
let scrolling_target = &mut self.data.scrolling_target;
let mut perform_next_tick = false;
// check for boundaries
if !self.data.swipe_running {
// top bound
if scrolling_target.y < 0.0 {
self.data.scrolling_velocity.y *= KINETIC_VELOCITY_BRAKE;
scrolling_target.y *= RUBBERBANDING_DAMP;
perform_next_tick = true;
}
// left bound
if scrolling_target.x < 0.0 {
self.data.scrolling_velocity.x *= KINETIC_VELOCITY_BRAKE;
scrolling_target.x *= RUBBERBANDING_DAMP;
perform_next_tick = true;
}
// right bound
if scrolling_target.x > 1.0 {
self.data.scrolling_velocity.x *= KINETIC_VELOCITY_BRAKE;
scrolling_target.x = 1.0.lerp(scrolling_target.x, RUBBERBANDING_DAMP);
perform_next_tick = true;
}
// bottom bound
if scrolling_target.y > 1.0 {
self.data.scrolling_velocity.y *= KINETIC_VELOCITY_BRAKE;
scrolling_target.y = 1.0.lerp(scrolling_target.y, RUBBERBANDING_DAMP);
perform_next_tick = true;
}
}
// Perform kinetic velocity animation
if self.data.scrolling_velocity.length_squared() > 1e-9 {
*scrolling_target += self.data.scrolling_velocity;
self.data.scrolling_velocity *= KINETIC_VELOCITY_DAMPING;
perform_next_tick = true;
}
*scrolling_cur_prev = *scrolling_cur;
if scrolling_cur != scrolling_target {
// the magic part
*scrolling_cur = scrolling_cur.lerp(*scrolling_target, 0.2);
// trigger tick request again
perform_next_tick = true;
let epsilon = 0.00001;
if (scrolling_cur.x - scrolling_target.x).abs() < epsilon
&& (scrolling_cur.y - scrolling_target.y).abs() < epsilon
{
*scrolling_cur = *scrolling_target;
}
}
if perform_next_tick {
alterables.mark_tick(this_widget_id);
alterables.mark_redraw();
}
}
pub fn draw_scrollbars(&mut self, state: &mut DrawState, params: &DrawParams, info: &ScrollbarInfo) {
let (enabled_horiz, enabled_vert) = get_scroll_enabled(params.style);
if !enabled_horiz && !enabled_vert {
return;
}
let transform_widget = state.transform_stack.get();
let transform_parent = state.transform_stack.parent();
let thickness = 6.0;
let margin = 6.0;
let rect_params = drawing::Rectangle {
color: drawing::Color::new(1.0, 1.0, 1.0, 0.5),
round_units: 4,
..Default::default()
};
#[allow(clippy::useless_let_if_seq)]
let mut boundary: Option<drawing::Boundary> = None;
// Horizontal handle
if enabled_horiz && info.handle_size.x < 1.0 {
boundary = Some(drawing::Boundary::from_pos_size(
Vec2::new(
// X
transform_widget.content_rel_pos.x
+ transform_parent.raw_dim.x * (1.0 - info.handle_size.x) * self.data.scrolling_cur.x.clamp(0.0, 1.0),
// Y
transform_widget.content_rel_pos.y + transform_widget.raw_dim.y - thickness - margin,
),
Vec2::new(transform_widget.raw_dim.x * info.handle_size.x, thickness),
));
}
// Vertical handle
if enabled_vert && info.handle_size.y < 1.0 {
boundary = Some(drawing::Boundary::from_pos_size(
Vec2::new(
// X
transform_widget.content_rel_pos.x + transform_widget.raw_dim.x - thickness - margin,
// Y
transform_widget.content_rel_pos.y
+ transform_parent.raw_dim.y * (1.0 - info.handle_size.y) * self.data.scrolling_cur.y.clamp(0.0, 1.0),
),
Vec2::new(thickness, transform_widget.raw_dim.y * info.handle_size.y),
));
}
if let Some(boundary) = boundary.take() {
state.primitives.push(drawing::RenderPrimitive::Rectangle(
PrimitiveExtent {
boundary,
transform: transform_parent.transform,
},
rect_params,
));
}
}
fn process_wheel(&mut self, params: &mut EventParams, wheel: &MouseWheelEvent) -> bool {
let (enabled_horiz, enabled_vert) = get_scroll_enabled(params.style);
if !enabled_horiz && !enabled_vert {
return false;
}
let l = params.taffy_layout;
let overflow = Vec2::new(l.scroll_width(), l.scroll_height());
if overflow.x == 0.0 && overflow.y == 0.0 {
return false; // not overflowing
}
let Some(info) = get_scrollbar_info(l) else {
return false;
};
let step_pixels = 64.0;
let mut handle_scroll =
|scrolling_target: &mut f32, wheel_delta: f32, handle_size: f32, content_length: f32, content_box_length: f32| {
if handle_size >= 1.0 || wheel_delta == 0.0 {
return;
}
let mult = (1.0 / (content_box_length - content_length)) * step_pixels;
let new_scroll = *scrolling_target + wheel_delta * mult;
if *scrolling_target == new_scroll {
return;
}
*scrolling_target = new_scroll;
params.alterables.mark_tick(self.obj.get_id());
};
handle_scroll(
&mut self.data.scrolling_target.x,
wheel.delta.x,
info.handle_size.x,
info.content_size.x,
l.content_box_width(),
);
handle_scroll(
&mut self.data.scrolling_target.y,
wheel.delta.y,
info.handle_size.y,
info.content_size.y,
l.content_box_height(),
);
true
}
// this is called before calling children of this widget
pub fn process_event_priority(
&mut self,
params: &mut EventParams,
widget_id: WidgetID,
event: &Event,
) -> anyhow::Result<EventResult> {
match &event {
Event::MouseUp(_e) => {
if self.data.swipe_running {
self.data.swipe_running = false;
let kinetic_force = (self.data.scrolling_cur - self.data.scrolling_cur_prev) * 20.0;
self.data.scrolling_velocity += kinetic_force;
params.alterables.mark_tick(widget_id);
params.alterables.mark_redraw();
}
self.data.press_down_start_mouse_pos = None;
}
Event::MouseMotion(e) => {
if let Some(start_mouse_pos) = &self.data.press_down_start_mouse_pos {
let (active_x, active_y) = get_scroll_active_axis(params.style, params.taffy_layout);
if !self.data.swipe_running
&& ((active_x && (e.pos.x - start_mouse_pos.x).abs() >= SWIPE_START_THRESHOLD_UNITS)
|| (active_y && (e.pos.y - start_mouse_pos.y).abs() >= SWIPE_START_THRESHOLD_UNITS))
{
self.data.swipe_running = true;
params.alterables.emit_global_event(Event::MouseCancel);
}
if self.data.swipe_running
&& let Some(scrollbar_info) = get_scrollbar_info(params.taffy_layout)
{
let mouse_diff = e.pos - start_mouse_pos;
let mult = scrollbar_info.get_potential_scroll_axis_multiplier(params.taffy_layout);
let scroll_diff_x = if mult.x == 0.0 { 0.0 } else { -mouse_diff.x / mult.x };
let scroll_diff_y = if mult.y == 0.0 { 0.0 } else { -mouse_diff.y / mult.y };
self.data.scrolling_target = self.data.swipe_scroll_start + Vec2::new(scroll_diff_x, scroll_diff_y);
params.alterables.mark_tick(self.obj.get_id());
return Ok(EventResult::Consumed);
}
}
}
_ => {}
}
Ok(EventResult::Pass)
}
fn process_swipe_event(&mut self, event: &Event, params: &EventParams) {
let Event::MouseDown(evt) = &event else {
return;
};
// firstly, check if this widget is scrollable at all
let (active_x, active_y) = get_scroll_active_axis(params.style, params.taffy_layout);
if !active_x && !active_y {
return;
}
// check if the mouse hovers over *parent* boundaries
// we assume there that our parent is non-scrollable
let transform_parent = params.alterables.transform_stack.parent();
if !Event::test_transform_pos(transform_parent, evt.pos) {
return;
}
self.data.press_down_start_mouse_pos = Some(evt.pos);
self.data.swipe_scroll_start = self.data.scrolling_target;
}
pub fn process_event<'a, 'b, U1: 'static, U2: 'static>(
&mut self,
params: &'a mut EventParams<'a>,
widget_id: WidgetID,
event: &Event,
event_result: &'a mut EventResult,
user_data: &'a mut (&'b mut U1, &'b mut U2),
) -> anyhow::Result<()> {
// check if we should swipe-scroll this widget
if *event_result != EventResult::ConsumedExclusive {
self.process_swipe_event(event, params);
}
if !event_result.can_propagate() {
// we don't want to pass any other events
return Ok(());
}
let hovered = event.test_mouse_within_transform(
params.alterables.transform_stack.get(),
&params.alterables.scissor_stack.get().0,
);
let mut invoke_data = InvokeData {
widget_id,
node_id: params.node_id,
event_result,
user_data,
params,
};
let mut res: Option<InvokeListenersResult> = None;
match &event {
Event::TextInput(e) => {
res = Some(self.invoke_listeners(
&mut invoke_data,
EventListenerKind::TextInput,
CallbackMetadata::TextInput(e.clone()),
)?);
}
Event::MouseCancel => {
res = Some(self.invoke_listeners(&mut invoke_data, EventListenerKind::MouseCancel, CallbackMetadata::None)?);
}
Event::MouseDown(e) => {
if hovered && self.data.set_device_pressed(e.device, true) {
res = Some(self.invoke_listeners(
&mut invoke_data,
EventListenerKind::MousePress,
CallbackMetadata::MouseButton(*e),
)?);
}
}
Event::MouseUp(e) => {
if self.data.set_device_pressed(e.device, false) {
res = Some(self.invoke_listeners(
&mut invoke_data,
EventListenerKind::MouseRelease,
CallbackMetadata::MouseButton(*e),
)?);
}
}
Event::MouseMotion(e) => {
let hover_state_changed = self.data.set_device_hovered(e.device, hovered);
if hover_state_changed {
if self.data.is_hovered() {
res =
Some(self.invoke_listeners(&mut invoke_data, EventListenerKind::MouseEnter, CallbackMetadata::None)?);
} else {
res =
Some(self.invoke_listeners(&mut invoke_data, EventListenerKind::MouseLeave, CallbackMetadata::None)?);
}
} else {
res = Some(self.invoke_listeners(
&mut invoke_data,
EventListenerKind::MouseMotion,
CallbackMetadata::MousePosition(event::MousePosition {
pos: e.pos,
device: e.device,
}),
)?);
if self.flags.interactable {
*invoke_data.event_result = invoke_data.event_result.merge(EventResult::Pass);
}
}
}
Event::MouseWheel(e) => {
if hovered && self.process_wheel(invoke_data.params, e) {
*invoke_data.event_result = EventResult::Consumed;
return Ok(());
}
}
Event::MouseLeave(e) => {
if self.data.set_device_hovered(e.device, false) {
res = Some(self.invoke_listeners(&mut invoke_data, MouseLeave, CallbackMetadata::None)?);
}
}
Event::InternalStateChange(e) => {
res = Some(self.invoke_listeners(
&mut invoke_data,
InternalStateChange,
CallbackMetadata::Custom(e.metadata),
)?);
}
}
if let Some(res) = res {
match res {
InvokeListenersResult::NobodyListened => {
if hovered && self.flags.consume_mouse_events {
*invoke_data.event_result = EventResult::Consumed;
}
}
InvokeListenersResult::AtLeastOneCalled => {}
}
}
Ok(())
}
}
pub struct ConstructEssentials<'a> {
pub layout: &'a mut Layout,
pub parent: WidgetID,
}
/// Determines whether a given node is visible within the layout tree.
///
/// Traversal is definitely a little bit more expensive than just checking the value, but
/// Taffy doesn't calculate that for us, so here it is.
pub fn is_node_visible(tree: &TaffyTree<WidgetID>, node_id: NodeId) -> bool {
let mut cur = Some(node_id);
while let Some(node_id) = cur {
if let Ok(style) = tree.style(node_id)
&& style.display == taffy::Display::None
{
return false;
}
cur = tree.parent(node_id);
}
true
}