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libservo: Add a WebView::take_screenshot() API and use it for reftests

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Co-authored-by: Delan Azabani <dazabani@igalia.com>
Signed-off-by: Martin Robinson <mrobinson@igalia.com>
This commit is contained in:
Martin Robinson 2025-09-26 09:24:24 +02:00
parent 92dd54b1ec
commit ebb12cb298
25 changed files with 481 additions and 414 deletions
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1
components/compositing/Cargo.toml
View file

@ -31,6 +31,7 @@ dpi = { workspace = true }
embedder_traits = { workspace = true }
euclid = { workspace = true }
gleam = { workspace = true }
image = { workspace = true }
ipc-channel = { workspace = true }
libc = { workspace = true }
log = { workspace = true }

249
components/compositing/compositor.rs
View file

@ -26,8 +26,11 @@ use compositing_traits::{
use constellation_traits::{EmbedderToConstellationMessage, PaintMetricEvent};
use crossbeam_channel::Sender;
use dpi::PhysicalSize;
use embedder_traits::{CompositorHitTestResult, InputEvent, ShutdownState, ViewportDetails};
use embedder_traits::{
CompositorHitTestResult, InputEvent, ScreenshotCaptureError, ShutdownState, ViewportDetails,
};
use euclid::{Point2D, Rect, Scale, Size2D, Transform3D};
use image::RgbaImage;
use ipc_channel::ipc::{self, IpcSharedMemory};
use log::{debug, info, trace, warn};
use pixels::{CorsStatus, ImageFrame, ImageMetadata, PixelFormat, RasterImage};
@ -37,7 +40,7 @@ use profile_traits::mem::{
use profile_traits::time::{self as profile_time, ProfilerCategory};
use profile_traits::{path, time_profile};
use rustc_hash::{FxHashMap, FxHashSet};
use servo_config::{opts, pref};
use servo_config::pref;
use servo_geometry::DeviceIndependentPixel;
use style_traits::CSSPixel;
use webrender::{CaptureBits, RenderApi, Transaction};
@ -58,26 +61,6 @@ use crate::refresh_driver::RefreshDriver;
use crate::webview_manager::WebViewManager;
use crate::webview_renderer::{PinchZoomResult, UnknownWebView, WebViewRenderer};
#[derive(Debug, PartialEq)]
pub enum UnableToComposite {
NotReadyToPaintImage(NotReadyToPaint),
}
#[derive(Debug, PartialEq)]
pub enum NotReadyToPaint {
JustNotifiedConstellation,
WaitingOnConstellation,
}
/// Holds the state when running reftests that determines when it is
/// safe to save the output image.
#[derive(Clone, Copy, Debug, PartialEq)]
enum ReadyState {
Unknown,
WaitingForConstellationReply,
ReadyToSaveImage,
}
/// An option to control what kind of WebRender debugging is enabled while Servo is running.
#[derive(Clone)]
pub enum WebRenderDebugOption {
@ -125,6 +108,11 @@ pub struct ServoRenderer {
/// arrive before requesting a new frame, as these happen asynchronously with
/// `ScriptThread` display list construction.
frame_delayer: FrameDelayer,
/// A vector of pending screenshots to be taken. These will be resolved once the
/// pages have finished loading all content and the rendering reflects the finished
/// state.
screenshot_requests: Vec<ScreenshotRequest>,
}
/// NB: Never block on the constellation, because sometimes the constellation blocks on us.
@ -138,10 +126,6 @@ pub struct IOCompositor {
/// Tracks whether or not the view needs to be repainted.
needs_repaint: Cell<RepaintReason>,
/// Used by the logic that determines when it is safe to output an
/// image for the reftest framework.
ready_to_save_state: ReadyState,
/// The webrender renderer.
webrender: Option<webrender::Renderer>,
@ -326,10 +310,10 @@ impl IOCompositor {
webxr_main_thread: state.webxr_main_thread,
last_mouse_move_position: None,
frame_delayer: Default::default(),
screenshot_requests: Default::default(),
})),
webview_renderers: WebViewManager::default(),
needs_repaint: Cell::default(),
ready_to_save_state: ReadyState::Unknown,
webrender: Some(state.webrender),
rendering_context: state.rendering_context,
pending_frames: Cell::new(0),
@ -492,18 +476,6 @@ impl IOCompositor {
};
webview_renderer.on_touch_event_processed(result);
},
CompositorMsg::IsReadyToSaveImageReply(is_ready) => {
assert_eq!(
self.ready_to_save_state,
ReadyState::WaitingForConstellationReply
);
if is_ready && self.pending_frames.get() == 0 {
self.ready_to_save_state = ReadyState::ReadyToSaveImage;
} else {
self.ready_to_save_state = ReadyState::Unknown;
}
self.set_needs_repaint(RepaintReason::ReadyForScreenshot);
},
CompositorMsg::SetThrottled(webview_id, pipeline_id, throttled) => {
let Some(webview_renderer) = self.webview_renderers.get_mut(webview_id) else {
@ -532,12 +504,6 @@ impl IOCompositor {
self.handle_new_webrender_frame_ready(recomposite_needed);
},
CompositorMsg::LoadComplete(_) => {
if opts::get().wait_for_stable_image {
self.set_needs_repaint(RepaintReason::ReadyForScreenshot);
}
},
CompositorMsg::SendInitialTransaction(pipeline) => {
let mut txn = Transaction::new();
txn.set_display_list(WebRenderEpoch(0), (pipeline, Default::default()));
@ -805,6 +771,9 @@ impl IOCompositor {
webview.set_viewport_description(viewport_description);
}
},
CompositorMsg::ScreenshotReadinessReponse(webview_id, pipelines_and_epochs) => {
self.handle_screenshot_readiness_reply(webview_id, pipelines_and_epochs);
},
}
}
@ -1168,78 +1137,19 @@ impl IOCompositor {
.any(WebViewRenderer::animation_callbacks_running)
}
/// Query the constellation to see if the current compositor
/// output matches the current frame tree output, and if the
/// associated script threads are idle.
fn is_ready_to_paint_image_output(&mut self) -> Result<(), NotReadyToPaint> {
match self.ready_to_save_state {
ReadyState::Unknown => {
// Unsure if the output image is stable.
// Collect the currently painted epoch of each pipeline that is
// complete (i.e. has *all* layers painted to the requested epoch).
// This gets sent to the constellation for comparison with the current
// frame tree.
let mut pipeline_epochs = FxHashMap::default();
for id in self
.webview_renderers
.iter()
.flat_map(WebViewRenderer::pipeline_ids)
{
if let Some(WebRenderEpoch(epoch)) = self
.webrender
.as_ref()
.and_then(|wr| wr.current_epoch(self.webrender_document(), id.into()))
{
let epoch = Epoch(epoch);
pipeline_epochs.insert(*id, epoch);
}
}
// Pass the pipeline/epoch states to the constellation and check
// if it's safe to output the image.
let msg = EmbedderToConstellationMessage::IsReadyToSaveImage(pipeline_epochs);
if let Err(e) = self.global.borrow().constellation_sender.send(msg) {
warn!("Sending ready to save to constellation failed ({:?}).", e);
}
self.ready_to_save_state = ReadyState::WaitingForConstellationReply;
Err(NotReadyToPaint::JustNotifiedConstellation)
},
ReadyState::WaitingForConstellationReply => {
// If waiting on a reply from the constellation to the last
// query if the image is stable, then assume not ready yet.
Err(NotReadyToPaint::WaitingOnConstellation)
},
ReadyState::ReadyToSaveImage => {
// Constellation has replied at some point in the past
// that the current output image is stable and ready
// for saving.
// Reset the flag so that we check again in the future
// TODO: only reset this if we load a new document?
self.ready_to_save_state = ReadyState::Unknown;
Ok(())
},
}
}
/// Render the WebRender scene to the active `RenderingContext`. If successful, trigger
/// the next round of animations.
pub fn render(&mut self) -> bool {
pub fn render(&mut self) {
self.global
.borrow()
.refresh_driver
.notify_will_paint(self.webview_renderers.iter());
if let Err(error) = self.render_inner() {
warn!("Unable to render: {error:?}");
return false;
}
self.render_inner();
// We've painted the default target, which means that from the embedder's perspective,
// the scene no longer needs to be repainted.
self.needs_repaint.set(RepaintReason::empty());
true
}
/// Render the WebRender scene to the shared memory, without updating other state of this
@ -1248,8 +1158,8 @@ impl IOCompositor {
&mut self,
webview_id: WebViewId,
page_rect: Option<Rect<f32, CSSPixel>>,
) -> Result<Option<RasterImage>, UnableToComposite> {
self.render_inner()?;
) -> Option<RasterImage> {
self.render_inner();
let size = self.rendering_context.size2d().to_i32();
let rect = if let Some(rect) = page_rect {
@ -1272,8 +1182,7 @@ impl IOCompositor {
DeviceIntRect::from_origin_and_size(Point2D::origin(), size)
};
Ok(self
.rendering_context
self.rendering_context
.read_to_image(rect)
.map(|image| RasterImage {
metadata: ImageMetadata {
@ -1290,11 +1199,11 @@ impl IOCompositor {
bytes: ipc::IpcSharedMemory::from_bytes(&image),
id: None,
cors_status: CorsStatus::Safe,
}))
})
}
#[servo_tracing::instrument(skip_all)]
fn render_inner(&mut self) -> Result<(), UnableToComposite> {
fn render_inner(&mut self) {
if let Err(err) = self.rendering_context.make_current() {
warn!("Failed to make the rendering context current: {:?}", err);
}
@ -1304,12 +1213,6 @@ impl IOCompositor {
webrender.update();
}
if opts::get().wait_for_stable_image {
if let Err(result) = self.is_ready_to_paint_image_output() {
return Err(UnableToComposite::NotReadyToPaintImage(result));
}
}
self.rendering_context.prepare_for_rendering();
let time_profiler_chan = self.global.borrow().time_profiler_chan.clone();
@ -1331,7 +1234,7 @@ impl IOCompositor {
);
self.send_pending_paint_metrics_messages_after_composite();
Ok(())
self.create_screenshots_after_paint();
}
/// Send all pending paint metrics messages after a composite operation, which may advance
@ -1675,6 +1578,85 @@ impl IOCompositor {
self.set_needs_repaint(RepaintReason::NewWebRenderFrame);
}
}
pub fn request_screenshot(
&self,
webview_id: WebViewId,
callback: Box<dyn FnOnce(Result<RgbaImage, ScreenshotCaptureError>) + 'static>,
) {
let mut global = self.global.borrow_mut();
global.screenshot_requests.push(ScreenshotRequest {
webview_id,
state: ScreenshotRequestState::WaitingOnConstellation,
callback,
});
let _ = global.constellation_sender.send(
EmbedderToConstellationMessage::RequestScreenshotReadiness(webview_id),
);
}
fn handle_screenshot_readiness_reply(
&self,
webview_id: WebViewId,
expected_epochs: FxHashMap<PipelineId, Epoch>,
) {
let mut global = self.global.borrow_mut();
let expected_epochs = Rc::new(expected_epochs);
let mut any_became_ready = false;
for screenshot_request in global.screenshot_requests.iter_mut() {
if screenshot_request.webview_id != webview_id ||
screenshot_request.state != ScreenshotRequestState::WaitingOnConstellation
{
continue;
}
screenshot_request.state =
ScreenshotRequestState::WaitingOnWebRender(expected_epochs.clone());
any_became_ready = true;
}
if any_became_ready {
self.set_needs_repaint(RepaintReason::ReadyForScreenshot);
}
}
fn create_screenshots_after_paint(&self) {
let mut global = self.global.borrow_mut();
if global.screenshot_requests.is_empty() {
return;
}
let document_id = global.webrender_document;
let Some(webrender) = self.webrender.as_ref() else {
return;
};
// TODO: This can eventually just be `extract_if`. We need to have ownership
// of the ScreenshotRequest in order to call the `FnOnce` callabck.
let screenshots = global.screenshot_requests.drain(..);
global.screenshot_requests = screenshots
.filter_map(|screenshot_request| {
if !screenshot_request.screenshot_ready(webrender, &document_id) {
return Some(screenshot_request);
}
let callback = screenshot_request.callback;
let Some(webview_renderer) =
self.webview_renderers.get(screenshot_request.webview_id)
else {
callback(Err(ScreenshotCaptureError::WebViewDoesNotExist));
return None;
};
let result = self
.rendering_context
.read_to_image(webview_renderer.rect.to_i32())
.ok_or(ScreenshotCaptureError::CouldNotReadImage);
callback(result);
None
})
.collect();
}
}
/// A struct that is reponsible for delaying frame requests until all new canvas images
@ -1750,3 +1732,32 @@ impl FrameDelayer {
self.waiting_pipelines.drain().collect()
}
}
struct ScreenshotRequest {
webview_id: WebViewId,
state: ScreenshotRequestState,
callback: Box<dyn FnOnce(Result<RgbaImage, ScreenshotCaptureError>) + 'static>,
}
#[derive(PartialEq)]
enum ScreenshotRequestState {
WaitingOnConstellation,
WaitingOnWebRender(Rc<FxHashMap<PipelineId, Epoch>>),
}
impl ScreenshotRequest {
fn screenshot_ready(&self, webrender: &webrender::Renderer, &document_id: &DocumentId) -> bool {
let ScreenshotRequestState::WaitingOnWebRender(pipelines_and_epochs) = &self.state else {
return false;
};
pipelines_and_epochs
.iter()
.all(|(pipeline_id, necessary_epoch)| {
webrender
.current_epoch(document_id, pipeline_id.into())
.is_some_and(|rendered_epoch| {
rendered_epoch >= WebRenderEpoch(necessary_epoch.0)
})
})
}
}

3
components/compositing/tracing.rs
View file

@ -34,11 +34,9 @@ mod from_constellation {
Self::CreateOrUpdateWebView(..) => target!("CreateOrUpdateWebView"),
Self::RemoveWebView(..) => target!("RemoveWebView"),
Self::TouchEventProcessed(..) => target!("TouchEventProcessed"),
Self::IsReadyToSaveImageReply(..) => target!("IsReadyToSaveImageReply"),
Self::SetThrottled(..) => target!("SetThrottled"),
Self::NewWebRenderFrameReady(..) => target!("NewWebRenderFrameReady"),
Self::PipelineExited(..) => target!("PipelineExited"),
Self::LoadComplete(..) => target!("LoadComplete"),
Self::SendInitialTransaction(..) => target!("SendInitialTransaction"),
Self::SendScrollNode(..) => target!("SendScrollNode"),
Self::SendDisplayList { .. } => target!("SendDisplayList"),
@ -54,6 +52,7 @@ mod from_constellation {
Self::Viewport(..) => target!("Viewport"),
Self::GenerateImageKeysForPipeline(..) => target!("GenerateImageKeysForPipeline"),
Self::DelayNewFrameForCanvas(..) => target!("DelayFramesForCanvas"),
Self::ScreenshotReadinessReponse(..) => target!("ScreenshotReadinessResponse"),
}
}
}

6
components/compositing/webview_renderer.rs
View file

@ -3,7 +3,7 @@
* file, You can obtain one at https://mozilla.org/MPL/2.0/. */
use std::cell::RefCell;
use std::collections::hash_map::{Entry, Keys};
use std::collections::hash_map::Entry;
use std::rc::Rc;
use base::id::{PipelineId, WebViewId};
@ -132,10 +132,6 @@ impl WebViewRenderer {
.any(PipelineDetails::animation_callbacks_running)
}
pub(crate) fn pipeline_ids(&self) -> Keys<'_, PipelineId, PipelineDetails> {
self.pipelines.keys()
}
pub(crate) fn animating(&self) -> bool {
self.animating
}

6
components/config/opts.rs
View file

@ -15,11 +15,6 @@ use servo_url::ServoUrl;
/// Global flags for Servo, currently set on the command line.
#[derive(Clone, Debug, Deserialize, Serialize)]
pub struct Opts {
/// Whether or not Servo should wait for web content to go into an idle state, therefore
/// likely producing a stable output image. This is useful for taking screenshots of pages
/// after they have loaded.
pub wait_for_stable_image: bool,
/// `None` to disable the time profiler or `Some` to enable it with:
///
/// - an interval in seconds to cause it to produce output on that interval.
@ -167,7 +162,6 @@ pub enum OutputOptions {
impl Default for Opts {
fn default() -> Self {
Self {
wait_for_stable_image: false,
time_profiling: None,
time_profiler_trace_path: None,
nonincremental_layout: false,

321
components/constellation/constellation.rs
View file

@ -85,7 +85,7 @@
//! See <https://github.com/servo/servo/issues/14704>
use std::borrow::ToOwned;
use std::cell::OnceCell;
use std::cell::{Cell, OnceCell, RefCell};
use std::collections::hash_map::Entry;
use std::collections::{HashMap, HashSet, VecDeque};
use std::marker::PhantomData;
@ -120,8 +120,9 @@ use constellation_traits::{
EmbedderToConstellationMessage, IFrameLoadInfo, IFrameLoadInfoWithData, IFrameSandboxState,
IFrameSizeMsg, Job, LoadData, LoadOrigin, LogEntry, MessagePortMsg, NavigationHistoryBehavior,
PaintMetricEvent, PortMessageTask, PortTransferInfo, SWManagerMsg, SWManagerSenders,
ScriptToConstellationChan, ScriptToConstellationMessage, ServiceWorkerManagerFactory,
ServiceWorkerMsg, StructuredSerializedData, TraversalDirection, WindowSizeType,
ScreenshotReadinessResponse, ScriptToConstellationChan, ScriptToConstellationMessage,
ServiceWorkerManagerFactory, ServiceWorkerMsg, StructuredSerializedData, TraversalDirection,
WindowSizeType,
};
use crossbeam_channel::{Receiver, Select, Sender, unbounded};
use devtools_traits::{
@ -494,6 +495,11 @@ pub struct Constellation<STF, SWF> {
/// Pending viewport changes for browsing contexts that are not
/// yet known to the constellation.
pending_viewport_changes: HashMap<BrowsingContextId, ViewportDetails>,
/// Pending screenshot requests. These are collected until the screenshot is ready to
/// take place, at which point the Constellation informs the renderer that it can start
/// the process of taking the screenshot.
screenshot_requests: Vec<ConstellationScreenshotRequest>,
}
/// State needed to construct a constellation.
@ -554,18 +560,6 @@ pub struct InitialConstellationState {
pub async_runtime: Box<dyn AsyncRuntime>,
}
/// When we are running reftests, we save an image to compare against a reference.
/// This enum gives the possible states of preparing such an image.
#[derive(Debug, PartialEq)]
enum ReadyToSave {
NoTopLevelBrowsingContext,
PendingChanges,
DocumentLoading,
EpochMismatch,
PipelineUnknown,
Ready,
}
/// When we are exiting a pipeline, we can either force exiting or not.
/// A normal exit waits for the compositor to update its state before
/// exiting, and delegates layout exit to script. A forced exit does
@ -748,6 +742,7 @@ where
rippy_data,
)),
pending_viewport_changes: Default::default(),
screenshot_requests: Vec::new(),
};
constellation.run();
@ -1428,14 +1423,6 @@ where
NavigationHistoryBehavior::Push,
);
},
EmbedderToConstellationMessage::IsReadyToSaveImage(pipeline_states) => {
let is_ready = self.handle_is_ready_to_save_image(pipeline_states);
debug!("Ready to save image {:?}.", is_ready);
self.compositor_proxy
.send(CompositorMsg::IsReadyToSaveImageReply(
is_ready == ReadyToSave::Ready,
));
},
// Create a new top level browsing context. Will use response_chan to return
// the browsing context id.
EmbedderToConstellationMessage::NewWebView(url, webview_id, viewport_details) => {
@ -1579,6 +1566,9 @@ where
));
}
},
EmbedderToConstellationMessage::RequestScreenshotReadiness(webview_id) => {
self.handle_request_screenshot_readiness(webview_id)
},
}
}
@ -1838,13 +1828,6 @@ where
ScriptToConstellationMessage::SetDocumentState(state) => {
self.document_states.insert(source_pipeline_id, state);
},
ScriptToConstellationMessage::SetLayoutEpoch(epoch, response_sender) => {
if let Some(pipeline) = self.pipelines.get_mut(&source_pipeline_id) {
pipeline.layout_epoch = epoch;
}
response_sender.send(true).unwrap_or_default();
},
ScriptToConstellationMessage::LogEntry(thread_name, entry) => {
self.handle_log_entry(Some(webview_id), thread_name, entry);
},
@ -1999,6 +1982,9 @@ where
}
}
},
ScriptToConstellationMessage::RespondToScreenshotReadinessRequest(response) => {
self.handle_screenshot_readiness_response(source_pipeline_id, response);
},
}
}
@ -3746,6 +3732,8 @@ where
ExitPipelineMode::Normal,
);
}
self.process_pending_screenshot_requests();
}
#[servo_tracing::instrument(skip_all)]
@ -3764,19 +3752,7 @@ where
.get(&BrowsingContextId::from(webview_id))
.map(|ctx| ctx.pipeline_id == pipeline_id)
.unwrap_or(false);
if pipeline_is_top_level_pipeline {
// Is there any pending pipeline that will replace the current top level pipeline
let current_top_level_pipeline_will_be_replaced = self
.pending_changes
.iter()
.any(|change| change.browsing_context_id == webview_id);
if !current_top_level_pipeline_will_be_replaced {
// Notify embedder and compositor top level document finished loading.
self.compositor_proxy
.send(CompositorMsg::LoadComplete(webview_id));
}
} else {
if !pipeline_is_top_level_pipeline {
self.handle_subframe_loaded(pipeline_id);
}
}
@ -5011,44 +4987,48 @@ where
debug!("{}: Document ready to activate", pipeline_id);
// Find the pending change whose new pipeline id is pipeline_id.
let pending_index = self
let Some(pending_index) = self
.pending_changes
.iter()
.rposition(|change| change.new_pipeline_id == pipeline_id);
.rposition(|change| change.new_pipeline_id == pipeline_id)
else {
return;
};
// If it is found, remove it from the pending changes, and make it
// the active document of its frame.
if let Some(pending_index) = pending_index {
let change = self.pending_changes.swap_remove(pending_index);
// Notify the parent (if there is one).
let parent_pipeline_id = match change.new_browsing_context_info {
// This will be a new browsing context.
Some(ref info) => info.parent_pipeline_id,
// This is an existing browsing context.
None => match self.browsing_contexts.get(&change.browsing_context_id) {
Some(ctx) => ctx.parent_pipeline_id,
None => {
return warn!(
"{}: Activated document after closure of {}",
change.new_pipeline_id, change.browsing_context_id,
);
},
},
};
if let Some(parent_pipeline_id) = parent_pipeline_id {
if let Some(parent_pipeline) = self.pipelines.get(&parent_pipeline_id) {
let msg = ScriptThreadMessage::UpdatePipelineId(
parent_pipeline_id,
change.browsing_context_id,
change.webview_id,
pipeline_id,
UpdatePipelineIdReason::Navigation,
let change = self.pending_changes.swap_remove(pending_index);
self.process_pending_screenshot_requests();
// Notify the parent (if there is one).
let parent_pipeline_id = match change.new_browsing_context_info {
// This will be a new browsing context.
Some(ref info) => info.parent_pipeline_id,
// This is an existing browsing context.
None => match self.browsing_contexts.get(&change.browsing_context_id) {
Some(ctx) => ctx.parent_pipeline_id,
None => {
return warn!(
"{}: Activated document after closure of {}",
change.new_pipeline_id, change.browsing_context_id,
);
let _ = parent_pipeline.event_loop.send(msg);
}
},
},
};
if let Some(parent_pipeline_id) = parent_pipeline_id {
if let Some(parent_pipeline) = self.pipelines.get(&parent_pipeline_id) {
let msg = ScriptThreadMessage::UpdatePipelineId(
parent_pipeline_id,
change.browsing_context_id,
change.webview_id,
pipeline_id,
UpdatePipelineIdReason::Navigation,
);
let _ = parent_pipeline.event_loop.send(msg);
}
self.change_session_history(change);
}
self.change_session_history(change);
}
/// Called when the window is resized.
@ -5075,88 +5055,114 @@ where
self.switch_fullscreen_mode(browsing_context_id);
}
/// Checks the state of all script and layout pipelines to see if they are idle
/// and compares the current layout state to what the compositor has. This is used
/// to check if the output image is "stable" and can be written as a screenshot
/// for reftests.
/// Since this function is only used in reftests, we do not harden it against panic.
#[servo_tracing::instrument(skip_all)]
fn handle_is_ready_to_save_image(
&mut self,
pipeline_states: FxHashMap<PipelineId, Epoch>,
) -> ReadyToSave {
// Note that this function can panic, due to ipc-channel creation
// failure. Avoiding this panic would require a mechanism for dealing
// with low-resource scenarios.
//
// If there is no focus browsing context yet, the initial page has
// not loaded, so there is nothing to save yet.
let Some(webview_id) = self.webviews.focused_webview().map(|(id, _)| id) else {
return ReadyToSave::NoTopLevelBrowsingContext;
};
fn handle_request_screenshot_readiness(&mut self, webview_id: WebViewId) {
self.screenshot_requests
.push(ConstellationScreenshotRequest {
webview_id,
pipeline_states: Default::default(),
state: Default::default(),
});
self.process_pending_screenshot_requests();
}
fn process_pending_screenshot_requests(&mut self) {
for screenshot_request in &self.screenshot_requests {
self.maybe_trigger_pending_screenshot_readiness_request(screenshot_request);
}
}
fn maybe_trigger_pending_screenshot_readiness_request(
&self,
screenshot_request: &ConstellationScreenshotRequest,
) {
// Ignore this request if it is not pending.
if screenshot_request.state.get() != ScreenshotRequestState::Pending {
return;
}
// If there are pending loads, wait for those to complete.
if !self.pending_changes.is_empty() {
return ReadyToSave::PendingChanges;
return;
}
// Step through the fully active browsing contexts, checking that the script thread is idle,
// and that the current epoch of the layout matches what the compositor has painted. If all
// these conditions are met, then the output image should not change and a reftest
// screenshot can safely be written.
for browsing_context in self.fully_active_browsing_contexts_iter(webview_id) {
let pipeline_id = browsing_context.pipeline_id;
trace!(
"{}: Checking readiness of {}",
browsing_context.id, pipeline_id
);
*screenshot_request.pipeline_states.borrow_mut() = self
.fully_active_browsing_contexts_iter(screenshot_request.webview_id)
.filter_map(|browsing_context| {
let pipeline_id = browsing_context.pipeline_id;
let Some(pipeline) = self.pipelines.get(&pipeline_id) else {
// This can happen while Servo is shutting down, so just ignore it for now.
return None;
};
// If the rectangle for this BrowsingContext is zero, it will never be
// painted. In this case, don't query screenshot readiness as it won't
// contribute to the final output image.
if browsing_context.viewport_details.size == Size2D::zero() {
return None;
}
let _ = pipeline
.event_loop
.send(ScriptThreadMessage::RequestScreenshotReadiness(pipeline_id));
Some((pipeline_id, None))
})
.collect();
screenshot_request
.state
.set(ScreenshotRequestState::WaitingOnScript);
}
let pipeline = match self.pipelines.get(&pipeline_id) {
None => {
warn!("{}: Screenshot while closing", pipeline_id);
continue;
},
Some(pipeline) => pipeline,
};
// See if this pipeline has reached idle script state yet.
match self.document_states.get(&browsing_context.pipeline_id) {
Some(&DocumentState::Idle) => {},
Some(&DocumentState::Pending) | None => {
return ReadyToSave::DocumentLoading;
},
}
// Check the visible rectangle for this pipeline. If the constellation has received a
// size for the pipeline, then its painting should be up to date.
//
// If the rectangle for this pipeline is zero sized, it will
// never be painted. In this case, don't query the layout
// thread as it won't contribute to the final output image.
if browsing_context.viewport_details.size == Size2D::zero() {
continue;
}
// Get the epoch that the compositor has drawn for this pipeline and then check if the
// last laid out epoch matches what the compositor has drawn. If they match (and script
// is idle) then this pipeline won't change again and can be considered stable.
let compositor_epoch = pipeline_states.get(&browsing_context.pipeline_id);
match compositor_epoch {
Some(compositor_epoch) => {
if pipeline.layout_epoch != *compositor_epoch {
return ReadyToSave::EpochMismatch;
}
},
None => {
// The compositor doesn't know about this pipeline yet.
// Assume it hasn't rendered yet.
return ReadyToSave::PipelineUnknown;
},
}
#[servo_tracing::instrument(skip_all)]
fn handle_screenshot_readiness_response(
&mut self,
updated_pipeline_id: PipelineId,
response: ScreenshotReadinessResponse,
) {
if self.screenshot_requests.is_empty() {
return;
}
// All script threads are idle and layout epochs match compositor, so output image!
ReadyToSave::Ready
self.screenshot_requests.retain(|screenshot_request| {
if screenshot_request.state.get() != ScreenshotRequestState::WaitingOnScript {
return true;
}
let mut has_pending_pipeline = false;
let mut pipeline_states = screenshot_request.pipeline_states.borrow_mut();
pipeline_states.retain(|pipeline_id, state| {
if *pipeline_id != updated_pipeline_id {
has_pending_pipeline |= state.is_none();
return true;
}
match response {
ScreenshotReadinessResponse::Ready(epoch) => {
*state = Some(epoch);
true
},
ScreenshotReadinessResponse::NoLongerActive => false,
}
});
if has_pending_pipeline {
return true;
}
let pipelines_and_epochs = pipeline_states
.iter()
.map(|(pipeline_id, epoch)| {
(
*pipeline_id,
epoch.expect("Should have an epoch when pipeline is ready."),
)
})
.collect();
self.compositor_proxy
.send(CompositorMsg::ScreenshotReadinessReponse(
screenshot_request.webview_id,
pipelines_and_epochs,
));
false
});
}
/// Get the current activity of a pipeline.
@ -5510,6 +5516,13 @@ where
// Inform script, compositor that this pipeline has exited.
pipeline.send_exit_message_to_script(dbc);
// TODO: Also remove the pipeline from the screenshot requests?
self.process_pending_screenshot_requests();
self.handle_screenshot_readiness_response(
pipeline_id,
ScreenshotReadinessResponse::NoLongerActive,
);
debug!("{}: Closed", pipeline_id);
}
@ -5683,3 +5696,19 @@ where
CanvasPaintThread::start(self.compositor_proxy.cross_process_compositor_api.clone())
}
}
#[derive(Clone, Copy, Default, PartialEq)]
enum ScreenshotRequestState {
/// The Constellation has not yet forwarded the request to the pipelines of the
/// request's WebView.
#[default]
Pending,
/// The Constellation has forwarded the request to the pipelines of the request's
/// WebView.
WaitingOnScript,
}
struct ConstellationScreenshotRequest {
webview_id: WebViewId,
state: Cell<ScreenshotRequestState>,
pipeline_states: RefCell<FxHashMap<PipelineId, Option<Epoch>>>,
}

6
components/constellation/pipeline.rs
View file

@ -11,7 +11,6 @@ use background_hang_monitor::HangMonitorRegister;
use background_hang_monitor_api::{
BackgroundHangMonitorControlMsg, BackgroundHangMonitorRegister, HangMonitorAlert,
};
use base::Epoch;
use base::generic_channel::{self, GenericReceiver, GenericSender};
use base::id::{
BrowsingContextId, HistoryStateId, PipelineId, PipelineNamespace, PipelineNamespaceId,
@ -103,10 +102,6 @@ pub struct Pipeline {
/// The title of this pipeline's document.
pub title: String,
/// The last compositor [`Epoch`] that was laid out in this pipeline if "exit after load" is
/// enabled.
pub layout_epoch: Epoch,
pub focus_sequence: FocusSequenceNumber,
}
@ -395,7 +390,6 @@ impl Pipeline {
history_states: HashSet::new(),
completely_loaded: false,
title: String::new(),
layout_epoch: Epoch(0),
focus_sequence: FocusSequenceNumber::default(),
};

6
components/constellation/tracing.rs
View file

@ -50,7 +50,6 @@ mod from_compositor {
fn log_target(&self) -> &'static str {
match self {
Self::Exit => target!("Exit"),
Self::IsReadyToSaveImage(..) => target!("IsReadyToSaveImage"),
Self::AllowNavigationResponse(..) => target!("AllowNavigationResponse"),
Self::LoadUrl(..) => target!("LoadUrl"),
Self::ClearCache => target!("ClearCache"),
@ -82,6 +81,7 @@ mod from_compositor {
Self::NoLongerWaitingOnAsynchronousImageUpdates(..) => {
target!("NoLongerWaitingOnCanvas")
},
Self::RequestScreenshotReadiness(..) => target!("RequestScreenshotReadiness"),
}
}
}
@ -163,7 +163,6 @@ mod from_script {
Self::CreateAuxiliaryWebView(..) => target!("ScriptNewAuxiliary"),
Self::ActivateDocument => target!("ActivateDocument"),
Self::SetDocumentState(..) => target!("SetDocumentState"),
Self::SetLayoutEpoch(..) => target!("SetLayoutEpoch"),
Self::SetFinalUrl(..) => target!("SetFinalUrl"),
Self::TouchEventProcessed(..) => target!("TouchEventProcessed"),
Self::LogEntry(..) => target!("LogEntry"),
@ -183,6 +182,9 @@ mod from_script {
Self::WebDriverInputComplete(..) => target!("WebDriverInputComplete"),
Self::FinishJavaScriptEvaluation(..) => target!("FinishJavaScriptEvaluation"),
Self::ForwardKeyboardScroll(..) => target!("ForwardKeyboardScroll"),
Self::RespondToScreenshotReadinessRequest(..) => {
target!("RespondToScreenshotReadinessRequest")
},
}
}
}

74
components/script/dom/window.rs
View file

@ -26,8 +26,9 @@ use bluetooth_traits::BluetoothRequest;
use canvas_traits::webgl::WebGLChan;
use compositing_traits::CrossProcessCompositorApi;
use constellation_traits::{
DocumentState, LoadData, LoadOrigin, NavigationHistoryBehavior, ScriptToConstellationChan,
ScriptToConstellationMessage, StructuredSerializedData, WindowSizeType,
LoadData, LoadOrigin, NavigationHistoryBehavior, ScreenshotReadinessResponse,
ScriptToConstellationChan, ScriptToConstellationMessage, StructuredSerializedData,
WindowSizeType,
};
use crossbeam_channel::{Sender, unbounded};
use cssparser::SourceLocation;
@ -42,7 +43,7 @@ use embedder_traits::{
use euclid::default::{Point2D as UntypedPoint2D, Rect as UntypedRect, Size2D as UntypedSize2D};
use euclid::{Point2D, Scale, Size2D, Vector2D};
use fonts::FontContext;
use ipc_channel::ipc::{self, IpcSender};
use ipc_channel::ipc::IpcSender;
use js::glue::DumpJSStack;
use js::jsapi::{
GCReason, Heap, JS_GC, JSAutoRealm, JSContext as RawJSContext, JSObject, JSPROP_ENUMERATE,
@ -80,9 +81,10 @@ use script_bindings::root::Root;
use script_traits::{ConstellationInputEvent, ScriptThreadMessage};
use selectors::attr::CaseSensitivity;
use servo_arc::Arc as ServoArc;
use servo_config::{opts, pref};
use servo_config::pref;
use servo_geometry::{DeviceIndependentIntRect, f32_rect_to_au_rect};
use servo_url::{ImmutableOrigin, MutableOrigin, ServoUrl};
use style::Zero;
use style::error_reporting::{ContextualParseError, ParseErrorReporter};
use style::properties::PropertyId;
use style::properties::style_structs::Font;
@ -441,6 +443,10 @@ pub(crate) struct Window {
/// <https://w3c.github.io/reporting/#windoworworkerglobalscope-endpoints>
#[no_trace]
endpoints_list: DomRefCell<Vec<ReportingEndpoint>>,
/// The number of pending screenshot readiness requests that we have received. We need
/// to send a response for each of these.
pending_screenshot_readiness_requests: Cell<usize>,
}
impl Window {
@ -2328,17 +2334,19 @@ impl Window {
}
document.update_animations_post_reflow();
self.update_constellation_epoch();
reflow_result.reflow_phases_run
}
pub(crate) fn maybe_send_idle_document_state_to_constellation(&self) {
if !opts::get().wait_for_stable_image {
return;
}
pub(crate) fn request_screenshot_readiness(&self) {
self.pending_screenshot_readiness_requests
.set(self.pending_screenshot_readiness_requests.get() + 1);
self.maybe_resolve_pending_screenshot_readiness_requests();
}
if self.has_sent_idle_message.get() {
pub(crate) fn maybe_resolve_pending_screenshot_readiness_requests(&self) {
let pending_requests = self.pending_screenshot_readiness_requests.get();
if pending_requests.is_zero() {
return;
}
@ -2371,17 +2379,20 @@ impl Window {
return;
}
// When all these conditions are met, notify the constellation
// that this pipeline is ready to write the image (from the script thread
// perspective at least).
debug!(
"{:?}: Sending DocumentState::Idle to Constellation",
self.pipeline_id()
);
self.send_to_constellation(ScriptToConstellationMessage::SetDocumentState(
DocumentState::Idle,
));
self.has_sent_idle_message.set(true);
// When all these conditions are met, notify the Constellation that we are ready to
// have our screenshot taken, when the given layout Epoch has been rendered.
let epoch = self.layout.borrow().current_epoch();
let pipeline_id = self.pipeline_id();
debug!("Ready to take screenshot of {pipeline_id:?} at epoch={epoch:?}");
for _ in 0..pending_requests {
self.send_to_constellation(
ScriptToConstellationMessage::RespondToScreenshotReadinessRequest(
ScreenshotReadinessResponse::Ready(epoch),
),
);
}
self.pending_screenshot_readiness_requests.set(0);
}
/// If parsing has taken a long time and reflows are still waiting for the `load` event,
@ -2445,24 +2456,6 @@ impl Window {
self.layout_blocker.get().layout_blocked()
}
/// If writing a screenshot, synchronously update the layout epoch that it set
/// in the constellation.
pub(crate) fn update_constellation_epoch(&self) {
if !opts::get().wait_for_stable_image {
return;
}
let epoch = self.layout.borrow().current_epoch();
debug!(
"{:?}: Updating constellation epoch: {epoch:?}",
self.pipeline_id()
);
let (sender, receiver) = ipc::channel().expect("Failed to create IPC channel!");
let event = ScriptToConstellationMessage::SetLayoutEpoch(epoch, sender);
self.send_to_constellation(event);
let _ = receiver.recv();
}
/// Trigger a reflow that is required by a certain queries.
pub(crate) fn layout_reflow(&self, query_msg: QueryMsg) {
self.reflow(ReflowGoal::LayoutQuery(query_msg));
@ -3192,9 +3185,7 @@ impl Window {
node.dirty(NodeDamage::Other);
}
}
}
impl Window {
#[allow(unsafe_code)]
#[allow(clippy::too_many_arguments)]
pub(crate) fn new(
@ -3325,6 +3316,7 @@ impl Window {
reporting_observer_list: Default::default(),
report_list: Default::default(),
endpoints_list: Default::default(),
pending_screenshot_readiness_requests: Default::default(),
});
WindowBinding::Wrap::<crate::DomTypeHolder>(GlobalScope::get_cx(), win)

1
components/script/messaging.rs
View file

@ -102,6 +102,7 @@ impl MixedMessage {
ScriptThreadMessage::PreferencesUpdated(..) => None,
ScriptThreadMessage::NoLongerWaitingOnAsychronousImageUpdates(_) => None,
ScriptThreadMessage::ForwardKeyboardScroll(id, _) => Some(*id),
ScriptThreadMessage::RequestScreenshotReadiness(id) => Some(*id),
},
MixedMessage::FromScript(inner_msg) => match inner_msg {
MainThreadScriptMsg::Common(CommonScriptMsg::Task(_, _, pipeline_id, _)) => {

36
components/script/script_thread.rs
View file

@ -38,8 +38,9 @@ use canvas_traits::webgl::WebGLPipeline;
use chrono::{DateTime, Local};
use compositing_traits::{CrossProcessCompositorApi, PipelineExitSource};
use constellation_traits::{
JsEvalResult, LoadData, LoadOrigin, NavigationHistoryBehavior, ScriptToConstellationChan,
ScriptToConstellationMessage, StructuredSerializedData, WindowSizeType,
JsEvalResult, LoadData, LoadOrigin, NavigationHistoryBehavior, ScreenshotReadinessResponse,
ScriptToConstellationChan, ScriptToConstellationMessage, StructuredSerializedData,
WindowSizeType,
};
use crossbeam_channel::unbounded;
use data_url::mime::Mime;
@ -1302,17 +1303,14 @@ impl ScriptThread {
}
}
/// If waiting for an idle `Pipeline` state in order to dump a screenshot at
/// the right time, inform the `Constellation` this `Pipeline` has entered
/// the idle state when applicable.
fn maybe_send_idle_document_state_to_constellation(&self) {
if !opts::get().wait_for_stable_image {
return;
}
/// If any `Pipeline`s are waiting to become ready for the purpose of taking a
/// screenshot, check to see if the `Pipeline` is now ready and send a message to the
/// Constellation, if so.
fn maybe_resolve_pending_screenshot_readiness_requests(&self) {
for (_, document) in self.documents.borrow().iter() {
document
.window()
.maybe_send_idle_document_state_to_constellation();
.maybe_resolve_pending_screenshot_readiness_requests();
}
}
@ -1539,7 +1537,7 @@ impl ScriptThread {
self.update_the_rendering(can_gc);
self.maybe_fulfill_font_ready_promises(can_gc);
self.maybe_send_idle_document_state_to_constellation();
self.maybe_resolve_pending_screenshot_readiness_requests();
// This must happen last to detect if any change above makes a rendering update necessary.
self.maybe_schedule_rendering_opportunity_after_ipc_message(built_any_display_lists);
@ -1916,6 +1914,9 @@ impl ScriptThread {
document.event_handler().do_keyboard_scroll(scroll);
}
},
ScriptThreadMessage::RequestScreenshotReadiness(pipeline_id) => {
self.handle_request_screenshot_readiness(pipeline_id);
},
}
}
@ -4024,6 +4025,19 @@ impl ScriptThread {
pub(crate) fn is_servo_privileged(url: ServoUrl) -> bool {
with_script_thread(|script_thread| script_thread.privileged_urls.contains(&url))
}
fn handle_request_screenshot_readiness(&self, pipeline_id: PipelineId) {
let Some(window) = self.documents.borrow().find_window(pipeline_id) else {
let _ = self.senders.pipeline_to_constellation_sender.send((
pipeline_id,
ScriptToConstellationMessage::RespondToScreenshotReadinessRequest(
ScreenshotReadinessResponse::NoLongerActive,
),
));
return;
};
window.request_screenshot_readiness();
}
}
impl Drop for ScriptThread {

1
components/servo/Cargo.toml
View file

@ -85,6 +85,7 @@ euclid = { workspace = true }
fonts = { path = "../fonts" }
gleam = { workspace = true }
gstreamer = { workspace = true, optional = true }
image = { workspace = true }
ipc-channel = { workspace = true }
keyboard-types = { workspace = true }
layout = { path = "../layout" }

6
components/servo/lib.rs
View file

@ -1059,14 +1059,10 @@ impl Servo {
pub fn execute_webdriver_command(&self, command: WebDriverCommandMsg) {
if let WebDriverCommandMsg::TakeScreenshot(webview_id, page_rect, response_sender) = command
{
let res = self
let img = self
.compositor
.borrow_mut()
.render_to_shared_memory(webview_id, page_rect);
if let Err(ref e) = res {
error!("Error retrieving PNG: {:?}", e);
}
let img = res.unwrap_or(None);
if let Err(e) = response_sender.send(img) {
error!("Sending reply to create png failed ({:?}).", e);
}

22
components/servo/webview.rs
View file

@ -14,9 +14,11 @@ use constellation_traits::{EmbedderToConstellationMessage, TraversalDirection};
use dpi::PhysicalSize;
use embedder_traits::{
Cursor, Image, InputEvent, JSValue, JavaScriptEvaluationError, LoadStatus,
MediaSessionActionType, ScreenGeometry, Theme, TraversalId, ViewportDetails,
MediaSessionActionType, ScreenGeometry, ScreenshotCaptureError, Theme, TraversalId,
ViewportDetails,
};
use euclid::{Point2D, Scale, Size2D};
use image::RgbaImage;
use servo_geometry::DeviceIndependentPixel;
use url::Url;
use webrender_api::ScrollLocation;
@ -560,11 +562,9 @@ impl WebView {
));
}
/// Paint the contents of this [`WebView`] into its `RenderingContext`. This will
/// always paint, unless the `Opts::wait_for_stable_image` option is enabled. In
/// that case, this might do nothing. Returns true if a paint was actually performed.
pub fn paint(&self) -> bool {
self.inner().compositor.borrow_mut().render()
/// Paint the contents of this [`WebView`] into its `RenderingContext`.
pub fn paint(&self) {
self.inner().compositor.borrow_mut().render();
}
/// Evaluate the specified string of JavaScript code. Once execution is complete or an error
@ -580,6 +580,16 @@ impl WebView {
Box::new(callback),
);
}
pub fn take_screenshot(
&self,
callback: impl FnOnce(Result<RgbaImage, ScreenshotCaptureError>) + 'static,
) {
self.inner()
.compositor
.borrow()
.request_screenshot(self.id(), Box::new(callback));
}
}
/// A structure used to expose a view of the [`WebView`] to the Servo

8
components/shared/compositing/lib.rs
View file

@ -12,6 +12,7 @@ use crossbeam_channel::Sender;
use embedder_traits::{AnimationState, EventLoopWaker, TouchEventResult};
use log::warn;
use malloc_size_of_derive::MallocSizeOf;
use rustc_hash::FxHashMap;
use smallvec::SmallVec;
use strum_macros::IntoStaticStr;
use webrender_api::{DocumentId, FontVariation};
@ -87,8 +88,6 @@ pub enum CompositorMsg {
RemoveWebView(WebViewId),
/// Script has handled a touch event, and either prevented or allowed default actions.
TouchEventProcessed(WebViewId, TouchEventResult),
/// A reply to the compositor asking if the output image is stable.
IsReadyToSaveImageReply(bool),
/// Set whether to use less resources by stopping animations.
SetThrottled(WebViewId, PipelineId, bool),
/// WebRender has produced a new frame. This message informs the compositor that
@ -100,8 +99,6 @@ pub enum CompositorMsg {
/// they have fully shut it down, to avoid recreating it due to any subsequent
/// messages.
PipelineExited(WebViewId, PipelineId, PipelineExitSource),
/// The load of a page has completed
LoadComplete(WebViewId),
/// Inform WebRender of the existence of this pipeline.
SendInitialTransaction(WebRenderPipelineId),
/// Perform a scroll operation.
@ -163,6 +160,9 @@ pub enum CompositorMsg {
CollectMemoryReport(ReportsChan),
/// A top-level frame has parsed a viewport metatag and is sending the new constraints.
Viewport(WebViewId, ViewportDescription),
/// Let the compositor know that the given WebView is ready to have a screenshot taken
/// after the given pipeline's epochs have been rendered.
ScreenshotReadinessReponse(WebViewId, FxHashMap<PipelineId, Epoch>),
}
impl Debug for CompositorMsg {

14
components/shared/constellation/from_script_message.rs
View file

@ -501,6 +501,16 @@ pub enum KeyboardScroll {
End,
}
#[derive(Debug, Deserialize, Serialize)]
pub enum ScreenshotReadinessResponse {
/// The Pipeline associated with this response, is ready for a screenshot at the
/// provided [`Epoch`].
Ready(Epoch),
/// The Pipeline associated with this response is no longer active and should be
/// ignored for the purposes of the screenshot.
NoLongerActive,
}
/// Messages from the script to the constellation.
#[derive(Deserialize, IntoStaticStr, Serialize)]
pub enum ScriptToConstellationMessage {
@ -641,8 +651,6 @@ pub enum ScriptToConstellationMessage {
ActivateDocument,
/// Set the document state for a pipeline (used by screenshot / reftests)
SetDocumentState(DocumentState),
/// Update the layout epoch in the constellation (used by screenshot / reftests).
SetLayoutEpoch(Epoch, IpcSender<bool>),
/// Update the pipeline Url, which can change after redirections.
SetFinalUrl(ServoUrl),
/// Script has handled a touch event, and either prevented or allowed default actions.
@ -688,6 +696,8 @@ pub enum ScriptToConstellationMessage {
WebDriverInputComplete(WebDriverMessageId),
/// Forward a keyboard scroll operation from an `<iframe>` to a parent pipeline.
ForwardKeyboardScroll(PipelineId, KeyboardScroll),
/// Notify the Constellation of the screenshot readiness of a given pipeline.
RespondToScreenshotReadinessRequest(ScreenshotReadinessResponse),
}
impl fmt::Debug for ScriptToConstellationMessage {

6
components/shared/constellation/lib.rs
View file

@ -15,7 +15,6 @@ use std::collections::VecDeque;
use std::fmt;
use std::time::Duration;
use base::Epoch;
use base::cross_process_instant::CrossProcessInstant;
use base::id::{MessagePortId, PipelineId, WebViewId};
use embedder_traits::{
@ -41,8 +40,6 @@ use webrender_api::{ExternalScrollId, ImageKey};
pub enum EmbedderToConstellationMessage {
/// Exit the constellation.
Exit,
/// Query the constellation to see if the current compositor output is stable
IsReadyToSaveImage(FxHashMap<PipelineId, Epoch>),
/// Whether to allow script to navigate.
AllowNavigationResponse(PipelineId, bool),
/// Request to load a page.
@ -109,6 +106,9 @@ pub enum EmbedderToConstellationMessage {
SetWebDriverResponseSender(IpcSender<WebDriverCommandResponse>),
/// A set of preferences were updated with the given new values.
PreferencesUpdated(Vec<(&'static str, PrefValue)>),
/// Request preparation for a screenshot of the given WebView. The Constellation will
/// send a message to the Embedder when the screenshot is ready to be taken.
RequestScreenshotReadiness(WebViewId),
}
/// A description of a paint metric that is sent from the Servo renderer to the

9
components/shared/embedder/lib.rs
View file

@ -1063,6 +1063,15 @@ pub enum JavaScriptEvaluationError {
SerializationError,
}
#[derive(Clone, Debug, Deserialize, PartialEq, Serialize)]
pub enum ScreenshotCaptureError {
/// The screenshot request failed to read the screenshot image from the `WebView`'s
/// `RenderingContext`.
CouldNotReadImage,
/// The WebView that this screenshot request was made for no longer exists.
WebViewDoesNotExist,
}
#[derive(Clone, Copy, Debug, Deserialize, Serialize)]
pub struct RgbColor {
pub red: u8,

4
components/shared/script/lib.rs
View file

@ -267,6 +267,10 @@ pub enum ScriptThreadMessage {
NoLongerWaitingOnAsychronousImageUpdates(PipelineId),
/// Forward a keyboard scroll operation from an `<iframe>` to a parent pipeline.
ForwardKeyboardScroll(PipelineId, KeyboardScroll),
/// Request readiness for a screenshot from the given pipeline. The pipeline will
/// respond when it is ready to take the screenshot or will not be able to take it
/// in the future.
RequestScreenshotReadiness(PipelineId),
}
impl fmt::Debug for ScriptThreadMessage {