servo/components/compositing/webview.rs
Martin Robinson c6dc7c83a8
libservo: Make zooming and HiDPI scaling work per-WebView (#36419)
libservo: Make zooming and HiDPI scaling work per-`WebView`

This change moves all zooming and HiDPI scaling to work per-`WebView` in
both libservo and Compositor. This means that you can pinch zoom one
`WebView` and it should now work independently of other `WebView`s.
This is accomplished by making each `WebView` in the WebRender scene
have its own scaling reference frame.

All WebViews are now expected to manage their HiDPI scaling factor and
this can be set independently of other WebViews. Perhaps in the future
this will become a Servo-wide setting.

This allows full removal of the `WindowMethods` trait from Servo.

Testing: There are not yet any tests for the WebView API, but I hope
to add those soon.

Co-authored-by: Shubham Gupta <shubham13297@gmail.com>
Signed-off-by: Martin Robinson <mrobinson@igalia.com>

Signed-off-by: Martin Robinson <mrobinson@igalia.com>
Co-authored-by: Shubham Gupta <shubham13297@gmail.com>
2025-04-14 12:01:49 +00:00

953 lines
40 KiB
Rust

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
use std::cell::RefCell;
use std::collections::HashMap;
use std::collections::hash_map::Keys;
use std::rc::Rc;
use base::id::{PipelineId, WebViewId};
use compositing_traits::{RendererWebView, SendableFrameTree};
use constellation_traits::{EmbedderToConstellationMessage, ScrollState, WindowSizeType};
use embedder_traits::{
AnimationState, CompositorHitTestResult, InputEvent, MouseButton, MouseButtonAction,
MouseButtonEvent, MouseMoveEvent, ShutdownState, TouchEvent, TouchEventResult, TouchEventType,
TouchId, ViewportDetails,
};
use euclid::{Box2D, Point2D, Scale, Size2D, Vector2D};
use fnv::FnvHashSet;
use log::{debug, warn};
use servo_geometry::DeviceIndependentPixel;
use style_traits::{CSSPixel, PinchZoomFactor};
use webrender::Transaction;
use webrender_api::units::{
DeviceIntPoint, DeviceIntRect, DevicePixel, DevicePoint, DeviceRect, LayoutVector2D,
};
use webrender_api::{
ExternalScrollId, HitTestFlags, RenderReasons, SampledScrollOffset, ScrollLocation,
};
use crate::IOCompositor;
use crate::compositor::{PipelineDetails, ServoRenderer};
use crate::touch::{TouchHandler, TouchMoveAction, TouchMoveAllowed, TouchSequenceState};
// Default viewport constraints
const MAX_ZOOM: f32 = 8.0;
const MIN_ZOOM: f32 = 0.1;
#[derive(Clone, Copy)]
struct ScrollEvent {
/// Scroll by this offset, or to Start or End
scroll_location: ScrollLocation,
/// Apply changes to the frame at this location
cursor: DeviceIntPoint,
/// The number of OS events that have been coalesced together into this one event.
event_count: u32,
}
#[derive(Clone, Copy)]
enum ScrollZoomEvent {
/// An pinch zoom event that magnifies the view by the given factor.
PinchZoom(f32),
/// A scroll event that scrolls the scroll node at the given location by the
/// given amount.
Scroll(ScrollEvent),
}
pub(crate) struct WebView {
/// The [`WebViewId`] of the `WebView` associated with this [`WebViewDetails`].
pub id: WebViewId,
/// The renderer's view of the embedding layer `WebView` as a trait implementation,
/// so that the renderer doesn't need to depend on the embedding layer. This avoids
/// a dependency cycle.
pub renderer_webview: Box<dyn RendererWebView>,
/// The root [`PipelineId`] of the currently displayed page in this WebView.
pub root_pipeline_id: Option<PipelineId>,
pub rect: DeviceRect,
/// Tracks details about each active pipeline that the compositor knows about.
pub pipelines: HashMap<PipelineId, PipelineDetails>,
/// Data that is shared by all WebView renderers.
pub(crate) global: Rc<RefCell<ServoRenderer>>,
/// Pending scroll/zoom events.
pending_scroll_zoom_events: Vec<ScrollZoomEvent>,
/// Touch input state machine
touch_handler: TouchHandler,
/// "Desktop-style" zoom that resizes the viewport to fit the window.
pub page_zoom: Scale<f32, CSSPixel, DeviceIndependentPixel>,
/// "Mobile-style" zoom that does not reflow the page.
viewport_zoom: PinchZoomFactor,
/// Viewport zoom constraints provided by @viewport.
min_viewport_zoom: Option<PinchZoomFactor>,
max_viewport_zoom: Option<PinchZoomFactor>,
/// The HiDPI scale factor for the `WebView` associated with this renderer. This is controlled
/// by the embedding layer.
hidpi_scale_factor: Scale<f32, DeviceIndependentPixel, DevicePixel>,
}
impl Drop for WebView {
fn drop(&mut self) {
self.global
.borrow_mut()
.pipeline_to_webview_map
.retain(|_, webview_id| self.id != *webview_id);
}
}
impl WebView {
pub(crate) fn new(
global: Rc<RefCell<ServoRenderer>>,
renderer_webview: Box<dyn RendererWebView>,
viewport_details: ViewportDetails,
) -> Self {
let hidpi_scale_factor = viewport_details.hidpi_scale_factor;
let size = viewport_details.size * viewport_details.hidpi_scale_factor;
Self {
id: renderer_webview.id(),
renderer_webview,
root_pipeline_id: None,
rect: DeviceRect::from_origin_and_size(DevicePoint::origin(), size),
pipelines: Default::default(),
touch_handler: TouchHandler::new(),
global,
pending_scroll_zoom_events: Default::default(),
page_zoom: Scale::new(1.0),
viewport_zoom: PinchZoomFactor::new(1.0),
min_viewport_zoom: Some(PinchZoomFactor::new(1.0)),
max_viewport_zoom: None,
hidpi_scale_factor: Scale::new(hidpi_scale_factor.0),
}
}
pub(crate) fn animations_or_animation_callbacks_running(&self) -> bool {
self.pipelines
.values()
.any(PipelineDetails::animations_or_animation_callbacks_running)
}
pub(crate) fn animation_callbacks_running(&self) -> bool {
self.pipelines
.values()
.any(PipelineDetails::animation_callbacks_running)
}
pub(crate) fn pipeline_ids(&self) -> Keys<'_, PipelineId, PipelineDetails> {
self.pipelines.keys()
}
/// Returns the [`PipelineDetails`] for the given [`PipelineId`], creating it if needed.
pub(crate) fn ensure_pipeline_details(
&mut self,
pipeline_id: PipelineId,
) -> &mut PipelineDetails {
self.pipelines.entry(pipeline_id).or_insert_with(|| {
self.global
.borrow_mut()
.pipeline_to_webview_map
.insert(pipeline_id, self.id);
PipelineDetails::new(pipeline_id)
})
}
pub(crate) fn set_throttled(&mut self, pipeline_id: PipelineId, throttled: bool) {
self.ensure_pipeline_details(pipeline_id).throttled = throttled;
}
pub(crate) fn remove_pipeline(&mut self, pipeline_id: PipelineId) {
self.global
.borrow_mut()
.pipeline_to_webview_map
.remove(&pipeline_id);
self.pipelines.remove(&pipeline_id);
}
pub(crate) fn set_frame_tree(&mut self, frame_tree: &SendableFrameTree) {
let pipeline_id = frame_tree.pipeline.id;
let old_pipeline_id = std::mem::replace(&mut self.root_pipeline_id, Some(pipeline_id));
if old_pipeline_id != self.root_pipeline_id {
debug!(
"Updating webview ({:?}) from pipeline {:?} to {:?}",
3, old_pipeline_id, self.root_pipeline_id
);
}
self.set_frame_tree_on_pipeline_details(frame_tree, None);
self.reset_scroll_tree_for_unattached_pipelines(frame_tree);
self.send_scroll_positions_to_layout_for_pipeline(pipeline_id);
}
pub(crate) fn send_scroll_positions_to_layout_for_pipeline(&self, pipeline_id: PipelineId) {
let Some(details) = self.pipelines.get(&pipeline_id) else {
return;
};
let mut scroll_states = Vec::new();
details.scroll_tree.nodes.iter().for_each(|node| {
if let (Some(scroll_id), Some(scroll_offset)) = (node.external_id(), node.offset()) {
scroll_states.push(ScrollState {
scroll_id,
scroll_offset,
});
}
});
let _ = self.global.borrow().constellation_sender.send(
EmbedderToConstellationMessage::SetScrollStates(pipeline_id, scroll_states),
);
}
pub(crate) fn set_frame_tree_on_pipeline_details(
&mut self,
frame_tree: &SendableFrameTree,
parent_pipeline_id: Option<PipelineId>,
) {
let pipeline_id = frame_tree.pipeline.id;
let pipeline_details = self.ensure_pipeline_details(pipeline_id);
pipeline_details.pipeline = Some(frame_tree.pipeline.clone());
pipeline_details.parent_pipeline_id = parent_pipeline_id;
for kid in &frame_tree.children {
self.set_frame_tree_on_pipeline_details(kid, Some(pipeline_id));
}
}
pub(crate) fn reset_scroll_tree_for_unattached_pipelines(
&mut self,
frame_tree: &SendableFrameTree,
) {
// TODO(mrobinson): Eventually this can selectively preserve the scroll trees
// state for some unattached pipelines in order to preserve scroll position when
// navigating backward and forward.
fn collect_pipelines(
pipelines: &mut FnvHashSet<PipelineId>,
frame_tree: &SendableFrameTree,
) {
pipelines.insert(frame_tree.pipeline.id);
for kid in &frame_tree.children {
collect_pipelines(pipelines, kid);
}
}
let mut attached_pipelines: FnvHashSet<PipelineId> = FnvHashSet::default();
collect_pipelines(&mut attached_pipelines, frame_tree);
self.pipelines
.iter_mut()
.filter(|(id, _)| !attached_pipelines.contains(id))
.for_each(|(_, details)| {
details.scroll_tree.nodes.iter_mut().for_each(|node| {
node.set_offset(LayoutVector2D::zero());
})
})
}
/// Sets or unsets the animations-running flag for the given pipeline. Returns true if
/// the pipeline is throttled.
pub(crate) fn change_running_animations_state(
&mut self,
pipeline_id: PipelineId,
animation_state: AnimationState,
) -> bool {
let throttled = {
let pipeline_details = self.ensure_pipeline_details(pipeline_id);
match animation_state {
AnimationState::AnimationsPresent => {
pipeline_details.animations_running = true;
},
AnimationState::AnimationCallbacksPresent => {
pipeline_details.animation_callbacks_running = true;
},
AnimationState::NoAnimationsPresent => {
pipeline_details.animations_running = false;
},
AnimationState::NoAnimationCallbacksPresent => {
pipeline_details.animation_callbacks_running = false;
},
}
pipeline_details.throttled
};
let animating = self.pipelines.values().any(PipelineDetails::animating);
self.renderer_webview.set_animating(animating);
throttled
}
pub(crate) fn tick_all_animations(&self, compositor: &IOCompositor) {
for pipeline_details in self.pipelines.values() {
pipeline_details.tick_animations(compositor)
}
}
pub(crate) fn tick_animations_for_pipeline(
&self,
pipeline_id: PipelineId,
compositor: &IOCompositor,
) {
if let Some(pipeline_details) = self.pipelines.get(&pipeline_id) {
pipeline_details.tick_animations(compositor);
}
}
/// On a Window refresh tick (e.g. vsync)
pub(crate) fn on_vsync(&mut self) {
if let Some(fling_action) = self.touch_handler.on_vsync() {
self.on_scroll_window_event(
ScrollLocation::Delta(fling_action.delta),
fling_action.cursor,
);
}
}
pub(crate) fn dispatch_input_event(&mut self, event: InputEvent) {
// Events that do not need to do hit testing are sent directly to the
// constellation to filter down.
let Some(point) = event.point() else {
return;
};
// If we can't find a pipeline to send this event to, we cannot continue.
let get_pipeline_details = |pipeline_id| self.pipelines.get(&pipeline_id);
let Some(result) = self
.global
.borrow()
.hit_test_at_point(point, get_pipeline_details)
else {
return;
};
self.global.borrow_mut().update_cursor(point, &result);
if let Err(error) = self.global.borrow().constellation_sender.send(
EmbedderToConstellationMessage::ForwardInputEvent(self.id, event, Some(result)),
) {
warn!("Sending event to constellation failed ({error:?}).");
}
}
pub(crate) fn notify_input_event(&mut self, event: InputEvent) {
if self.global.borrow().shutdown_state() != ShutdownState::NotShuttingDown {
return;
}
if let InputEvent::Touch(event) = event {
self.on_touch_event(event);
return;
}
if self.global.borrow().convert_mouse_to_touch {
match event {
InputEvent::MouseButton(event) => {
match event.action {
MouseButtonAction::Click => {},
MouseButtonAction::Down => self.on_touch_down(TouchEvent::new(
TouchEventType::Down,
TouchId(0),
event.point,
)),
MouseButtonAction::Up => self.on_touch_up(TouchEvent::new(
TouchEventType::Up,
TouchId(0),
event.point,
)),
}
return;
},
InputEvent::MouseMove(event) => {
self.on_touch_move(TouchEvent::new(
TouchEventType::Move,
TouchId(0),
event.point,
));
return;
},
_ => {},
}
}
self.dispatch_input_event(event);
}
fn send_touch_event(&self, mut event: TouchEvent) -> bool {
let get_pipeline_details = |pipeline_id| self.pipelines.get(&pipeline_id);
let Some(result) = self
.global
.borrow()
.hit_test_at_point(event.point, get_pipeline_details)
else {
return false;
};
event.init_sequence_id(self.touch_handler.current_sequence_id);
let event = InputEvent::Touch(event);
if let Err(e) = self.global.borrow().constellation_sender.send(
EmbedderToConstellationMessage::ForwardInputEvent(self.id, event, Some(result)),
) {
warn!("Sending event to constellation failed ({:?}).", e);
false
} else {
true
}
}
pub(crate) fn on_touch_event(&mut self, event: TouchEvent) {
if self.global.borrow().shutdown_state() != ShutdownState::NotShuttingDown {
return;
}
match event.event_type {
TouchEventType::Down => self.on_touch_down(event),
TouchEventType::Move => self.on_touch_move(event),
TouchEventType::Up => self.on_touch_up(event),
TouchEventType::Cancel => self.on_touch_cancel(event),
}
}
fn on_touch_down(&mut self, event: TouchEvent) {
self.touch_handler.on_touch_down(event.id, event.point);
self.send_touch_event(event);
}
fn on_touch_move(&mut self, mut event: TouchEvent) {
let action: TouchMoveAction = self.touch_handler.on_touch_move(event.id, event.point);
if TouchMoveAction::NoAction != action {
// if first move processed and allowed, we directly process the move event,
// without waiting for the script handler.
if self
.touch_handler
.move_allowed(self.touch_handler.current_sequence_id)
{
// https://w3c.github.io/touch-events/#cancelability
event.disable_cancelable();
match action {
TouchMoveAction::Scroll(delta, point) => self.on_scroll_window_event(
ScrollLocation::Delta(LayoutVector2D::from_untyped(delta.to_untyped())),
point.cast(),
),
TouchMoveAction::Zoom(magnification, scroll_delta) => {
let cursor = Point2D::new(-1, -1); // Make sure this hits the base layer.
// The order of these events doesn't matter, because zoom is handled by
// a root display list and the scroll event here is handled by the scroll
// applied to the content display list.
self.pending_scroll_zoom_events
.push(ScrollZoomEvent::PinchZoom(magnification));
self.pending_scroll_zoom_events
.push(ScrollZoomEvent::Scroll(ScrollEvent {
scroll_location: ScrollLocation::Delta(
LayoutVector2D::from_untyped(scroll_delta.to_untyped()),
),
cursor,
event_count: 1,
}));
},
_ => {},
}
}
// When the event is touchmove, if the script thread is processing the touch
// move event, we skip sending the event to the script thread.
// This prevents the script thread from stacking up for a large amount of time.
if !self
.touch_handler
.is_handling_touch_move(self.touch_handler.current_sequence_id) &&
self.send_touch_event(event) &&
event.is_cancelable()
{
self.touch_handler
.set_handling_touch_move(self.touch_handler.current_sequence_id, true);
}
}
}
fn on_touch_up(&mut self, event: TouchEvent) {
self.touch_handler.on_touch_up(event.id, event.point);
self.send_touch_event(event);
}
fn on_touch_cancel(&mut self, event: TouchEvent) {
// Send the event to script.
self.touch_handler.on_touch_cancel(event.id, event.point);
self.send_touch_event(event);
}
pub(crate) fn on_touch_event_processed(&mut self, result: TouchEventResult) {
match result {
TouchEventResult::DefaultPrevented(sequence_id, event_type) => {
debug!(
"Touch event {:?} in sequence {:?} prevented!",
event_type, sequence_id
);
match event_type {
TouchEventType::Down => {
// prevents both click and move
self.touch_handler.prevent_click(sequence_id);
self.touch_handler.prevent_move(sequence_id);
self.touch_handler
.remove_pending_touch_move_action(sequence_id);
},
TouchEventType::Move => {
// script thread processed the touch move event, mark this false.
if let Some(info) = self.touch_handler.get_touch_sequence_mut(sequence_id) {
info.prevent_move = TouchMoveAllowed::Prevented;
if let TouchSequenceState::PendingFling { .. } = info.state {
info.state = TouchSequenceState::Finished;
}
self.touch_handler.set_handling_touch_move(
self.touch_handler.current_sequence_id,
false,
);
self.touch_handler
.remove_pending_touch_move_action(sequence_id);
}
},
TouchEventType::Up => {
// Note: We don't have to consider PendingFling here, since we handle that
// in the DefaultAllowed case of the touch_move event.
// Note: Removing can and should fail, if we still have an active Fling,
let Some(info) =
&mut self.touch_handler.get_touch_sequence_mut(sequence_id)
else {
// The sequence ID could already be removed, e.g. if Fling finished,
// before the touch_up event was handled (since fling can start
// immediately if move was previously allowed, and clicks are anyway not
// happening from fling).
return;
};
match info.state {
TouchSequenceState::PendingClick(_) => {
info.state = TouchSequenceState::Finished;
self.touch_handler.remove_touch_sequence(sequence_id);
},
TouchSequenceState::Flinging { .. } => {
// We can't remove the touch sequence yet
},
TouchSequenceState::Finished => {
self.touch_handler.remove_touch_sequence(sequence_id);
},
TouchSequenceState::Touching |
TouchSequenceState::Panning { .. } |
TouchSequenceState::Pinching |
TouchSequenceState::MultiTouch |
TouchSequenceState::PendingFling { .. } => {
// It's possible to transition from Pinch to pan, Which means that
// a touch_up event for a pinch might have arrived here, but we
// already transitioned to pan or even PendingFling.
// We don't need to do anything in these cases though.
},
}
},
TouchEventType::Cancel => {
// We could still have pending event handlers, so we remove the pending
// actions, and try to remove the touch sequence.
self.touch_handler
.remove_pending_touch_move_action(sequence_id);
self.touch_handler.try_remove_touch_sequence(sequence_id);
},
}
},
TouchEventResult::DefaultAllowed(sequence_id, event_type) => {
debug!(
"Touch event {:?} in sequence {:?} allowed",
event_type, sequence_id
);
match event_type {
TouchEventType::Down => {},
TouchEventType::Move => {
if let Some(action) =
self.touch_handler.pending_touch_move_action(sequence_id)
{
match action {
TouchMoveAction::Scroll(delta, point) => self
.on_scroll_window_event(
ScrollLocation::Delta(LayoutVector2D::from_untyped(
delta.to_untyped(),
)),
point.cast(),
),
TouchMoveAction::Zoom(magnification, scroll_delta) => {
let cursor = Point2D::new(-1, -1);
// Make sure this hits the base layer.
// The order of these events doesn't matter, because zoom is handled by
// a root display list and the scroll event here is handled by the scroll
// applied to the content display list.
self.pending_scroll_zoom_events
.push(ScrollZoomEvent::PinchZoom(magnification));
self.pending_scroll_zoom_events
.push(ScrollZoomEvent::Scroll(ScrollEvent {
scroll_location: ScrollLocation::Delta(
LayoutVector2D::from_untyped(
scroll_delta.to_untyped(),
),
),
cursor,
event_count: 1,
}));
},
TouchMoveAction::NoAction => {
// This shouldn't happen, but we can also just ignore it.
},
}
self.touch_handler
.remove_pending_touch_move_action(sequence_id);
}
self.touch_handler
.set_handling_touch_move(self.touch_handler.current_sequence_id, false);
if let Some(info) = self.touch_handler.get_touch_sequence_mut(sequence_id) {
if info.prevent_move == TouchMoveAllowed::Pending {
info.prevent_move = TouchMoveAllowed::Allowed;
if let TouchSequenceState::PendingFling { velocity, cursor } =
info.state
{
info.state = TouchSequenceState::Flinging { velocity, cursor }
}
}
}
},
TouchEventType::Up => {
let Some(info) = self.touch_handler.get_touch_sequence_mut(sequence_id)
else {
// The sequence was already removed because there is no default action.
return;
};
match info.state {
TouchSequenceState::PendingClick(point) => {
info.state = TouchSequenceState::Finished;
// PreventDefault from touch_down may have been processed after
// touch_up already occurred.
if !info.prevent_click {
self.simulate_mouse_click(point);
}
self.touch_handler.remove_touch_sequence(sequence_id);
},
TouchSequenceState::Flinging { .. } => {
// We can't remove the touch sequence yet
},
TouchSequenceState::Finished => {
self.touch_handler.remove_touch_sequence(sequence_id);
},
TouchSequenceState::Panning { .. } |
TouchSequenceState::Pinching |
TouchSequenceState::PendingFling { .. } => {
// It's possible to transition from Pinch to pan, Which means that
// a touch_up event for a pinch might have arrived here, but we
// already transitioned to pan or even PendingFling.
// We don't need to do anything in these cases though.
},
TouchSequenceState::MultiTouch | TouchSequenceState::Touching => {
// We transitioned to touching from multi-touch or pinching.
},
}
},
TouchEventType::Cancel => {
self.touch_handler
.remove_pending_touch_move_action(sequence_id);
self.touch_handler.try_remove_touch_sequence(sequence_id);
},
}
},
}
}
/// <http://w3c.github.io/touch-events/#mouse-events>
fn simulate_mouse_click(&mut self, point: DevicePoint) {
let button = MouseButton::Left;
self.dispatch_input_event(InputEvent::MouseMove(MouseMoveEvent { point }));
self.dispatch_input_event(InputEvent::MouseButton(MouseButtonEvent {
button,
action: MouseButtonAction::Down,
point,
}));
self.dispatch_input_event(InputEvent::MouseButton(MouseButtonEvent {
button,
action: MouseButtonAction::Up,
point,
}));
self.dispatch_input_event(InputEvent::MouseButton(MouseButtonEvent {
button,
action: MouseButtonAction::Click,
point,
}));
}
pub(crate) fn notify_scroll_event(
&mut self,
scroll_location: ScrollLocation,
cursor: DeviceIntPoint,
event_type: TouchEventType,
) {
if self.global.borrow().shutdown_state() != ShutdownState::NotShuttingDown {
return;
}
match event_type {
TouchEventType::Move => self.on_scroll_window_event(scroll_location, cursor),
TouchEventType::Up | TouchEventType::Cancel => {
self.on_scroll_window_event(scroll_location, cursor);
},
TouchEventType::Down => {
self.on_scroll_window_event(scroll_location, cursor);
},
}
}
fn on_scroll_window_event(&mut self, scroll_location: ScrollLocation, cursor: DeviceIntPoint) {
self.pending_scroll_zoom_events
.push(ScrollZoomEvent::Scroll(ScrollEvent {
scroll_location,
cursor,
event_count: 1,
}));
}
pub(crate) fn process_pending_scroll_events(&mut self, compositor: &mut IOCompositor) {
if self.pending_scroll_zoom_events.is_empty() {
return;
}
// Batch up all scroll events into one, or else we'll do way too much painting.
let mut combined_scroll_event: Option<ScrollEvent> = None;
let mut combined_magnification = 1.0;
for scroll_event in self.pending_scroll_zoom_events.drain(..) {
match scroll_event {
ScrollZoomEvent::PinchZoom(magnification) => {
combined_magnification *= magnification
},
ScrollZoomEvent::Scroll(scroll_event_info) => {
let combined_event = match combined_scroll_event.as_mut() {
None => {
combined_scroll_event = Some(scroll_event_info);
continue;
},
Some(combined_event) => combined_event,
};
match (
combined_event.scroll_location,
scroll_event_info.scroll_location,
) {
(ScrollLocation::Delta(old_delta), ScrollLocation::Delta(new_delta)) => {
// Mac OS X sometimes delivers scroll events out of vsync during a
// fling. This causes events to get bunched up occasionally, causing
// nasty-looking "pops". To mitigate this, during a fling we average
// deltas instead of summing them.
let old_event_count = Scale::new(combined_event.event_count as f32);
combined_event.event_count += 1;
let new_event_count = Scale::new(combined_event.event_count as f32);
combined_event.scroll_location = ScrollLocation::Delta(
(old_delta * old_event_count + new_delta) / new_event_count,
);
},
(ScrollLocation::Start, _) | (ScrollLocation::End, _) => {
// Once we see Start or End, we shouldn't process any more events.
break;
},
(_, ScrollLocation::Start) | (_, ScrollLocation::End) => {
// If this is an event which is scrolling to the start or end of the page,
// disregard other pending events and exit the loop.
*combined_event = scroll_event_info;
break;
},
}
},
}
}
let zoom_changed =
self.set_pinch_zoom_level(self.pinch_zoom_level().get() * combined_magnification);
let scroll_result = combined_scroll_event.and_then(|combined_event| {
self.scroll_node_at_device_point(
combined_event.cursor.to_f32(),
combined_event.scroll_location,
)
});
if !zoom_changed && scroll_result.is_none() {
return;
}
let mut transaction = Transaction::new();
if zoom_changed {
compositor.send_root_pipeline_display_list_in_transaction(&mut transaction);
}
if let Some((pipeline_id, external_id, offset)) = scroll_result {
let offset = LayoutVector2D::new(-offset.x, -offset.y);
transaction.set_scroll_offsets(
external_id,
vec![SampledScrollOffset {
offset,
generation: 0,
}],
);
self.send_scroll_positions_to_layout_for_pipeline(pipeline_id);
}
compositor.generate_frame(&mut transaction, RenderReasons::APZ);
self.global.borrow_mut().send_transaction(transaction);
}
/// Perform a hit test at the given [`DevicePoint`] and apply the [`ScrollLocation`]
/// scrolling to the applicable scroll node under that point. If a scroll was
/// performed, returns the [`PipelineId`] of the node scrolled, the id, and the final
/// scroll delta.
fn scroll_node_at_device_point(
&mut self,
cursor: DevicePoint,
scroll_location: ScrollLocation,
) -> Option<(PipelineId, ExternalScrollId, LayoutVector2D)> {
let scroll_location = match scroll_location {
ScrollLocation::Delta(delta) => {
let device_pixels_per_page = self.device_pixels_per_page_pixel();
let scaled_delta = (Vector2D::from_untyped(delta.to_untyped()) /
device_pixels_per_page)
.to_untyped();
let calculated_delta = LayoutVector2D::from_untyped(scaled_delta);
ScrollLocation::Delta(calculated_delta)
},
// Leave ScrollLocation unchanged if it is Start or End location.
ScrollLocation::Start | ScrollLocation::End => scroll_location,
};
let get_pipeline_details = |pipeline_id| self.pipelines.get(&pipeline_id);
let hit_test_results = self
.global
.borrow()
.hit_test_at_point_with_flags_and_pipeline(
cursor,
HitTestFlags::FIND_ALL,
None,
get_pipeline_details,
);
// Iterate through all hit test results, processing only the first node of each pipeline.
// This is needed to propagate the scroll events from a pipeline representing an iframe to
// its ancestor pipelines.
let mut previous_pipeline_id = None;
for CompositorHitTestResult {
pipeline_id,
scroll_tree_node,
..
} in hit_test_results.iter()
{
let pipeline_details = self.pipelines.get_mut(pipeline_id)?;
if previous_pipeline_id.replace(pipeline_id) != Some(pipeline_id) {
let scroll_result = pipeline_details
.scroll_tree
.scroll_node_or_ancestor(scroll_tree_node, scroll_location);
if let Some((external_id, offset)) = scroll_result {
return Some((*pipeline_id, external_id, offset));
}
}
}
None
}
pub(crate) fn pinch_zoom_level(&self) -> Scale<f32, DevicePixel, DevicePixel> {
Scale::new(self.viewport_zoom.get())
}
fn set_pinch_zoom_level(&mut self, mut zoom: f32) -> bool {
if let Some(min) = self.min_viewport_zoom {
zoom = f32::max(min.get(), zoom);
}
if let Some(max) = self.max_viewport_zoom {
zoom = f32::min(max.get(), zoom);
}
let old_zoom = std::mem::replace(&mut self.viewport_zoom, PinchZoomFactor::new(zoom));
old_zoom != self.viewport_zoom
}
pub(crate) fn set_page_zoom(&mut self, magnification: f32) {
self.page_zoom =
Scale::new((self.page_zoom.get() * magnification).clamp(MIN_ZOOM, MAX_ZOOM));
}
pub(crate) fn device_pixels_per_page_pixel(&self) -> Scale<f32, CSSPixel, DevicePixel> {
self.page_zoom * self.hidpi_scale_factor * self.pinch_zoom_level()
}
pub(crate) fn device_pixels_per_page_pixel_not_including_pinch_zoom(
&self,
) -> Scale<f32, CSSPixel, DevicePixel> {
self.page_zoom * self.hidpi_scale_factor
}
/// Simulate a pinch zoom
pub(crate) fn set_pinch_zoom(&mut self, magnification: f32) {
if self.global.borrow().shutdown_state() != ShutdownState::NotShuttingDown {
return;
}
// TODO: Scroll to keep the center in view?
self.pending_scroll_zoom_events
.push(ScrollZoomEvent::PinchZoom(magnification));
}
fn send_window_size_message(&self) {
// The device pixel ratio used by the style system should include the scale from page pixels
// to device pixels, but not including any pinch zoom.
let device_pixel_ratio = self.device_pixels_per_page_pixel_not_including_pinch_zoom();
let initial_viewport = self.rect.size().to_f32() / device_pixel_ratio;
let msg = EmbedderToConstellationMessage::ChangeViewportDetails(
self.id,
ViewportDetails {
hidpi_scale_factor: device_pixel_ratio,
size: initial_viewport,
},
WindowSizeType::Resize,
);
if let Err(e) = self.global.borrow().constellation_sender.send(msg) {
warn!("Sending window resize to constellation failed ({:?}).", e);
}
}
/// Set the `hidpi_scale_factor` for this renderer, returning `true` if the value actually changed.
pub(crate) fn set_hidpi_scale_factor(
&mut self,
new_scale: Scale<f32, DeviceIndependentPixel, DevicePixel>,
) -> bool {
let old_scale_factor = std::mem::replace(&mut self.hidpi_scale_factor, new_scale);
if self.hidpi_scale_factor == old_scale_factor {
return false;
}
self.send_window_size_message();
true
}
/// Set the `rect` for this renderer, returning `true` if the value actually changed.
pub(crate) fn set_rect(&mut self, new_rect: DeviceRect) -> bool {
let old_rect = std::mem::replace(&mut self.rect, new_rect);
if old_rect.size() != self.rect.size() {
self.send_window_size_message();
}
old_rect != self.rect
}
pub(crate) fn client_window_rect(
&self,
rendering_context_size: Size2D<u32, DevicePixel>,
) -> Box2D<i32, DeviceIndependentPixel> {
let screen_geometry = self.renderer_webview.screen_geometry().unwrap_or_default();
let rect = DeviceIntRect::from_origin_and_size(
screen_geometry.offset,
rendering_context_size.to_i32(),
)
.to_f32() /
self.hidpi_scale_factor;
rect.to_i32()
}
pub(crate) fn screen_size(&self) -> Size2D<i32, DeviceIndependentPixel> {
let screen_geometry = self.renderer_webview.screen_geometry().unwrap_or_default();
(screen_geometry.size.to_f32() / self.hidpi_scale_factor).to_i32()
}
pub(crate) fn available_screen_size(&self) -> Size2D<i32, DeviceIndependentPixel> {
let screen_geometry = self.renderer_webview.screen_geometry().unwrap_or_default();
(screen_geometry.available_size.to_f32() / self.hidpi_scale_factor).to_i32()
}
}
#[derive(Clone, Copy, Debug, PartialEq)]
pub struct UnknownWebView(pub WebViewId);