Trait Layout 

pub trait Layout {
    // Required methods
    fn device(&self) -> &Device;
    fn set_theme(&mut self, theme: Theme) -> bool;
    fn set_viewport_details(
        &mut self,
        viewport_details: ViewportDetails,
    ) -> bool;
    fn add_stylesheet(
        &mut self,
        stylesheet: ServoArc<Stylesheet>,
        before_stylesheet: Option<ServoArc<Stylesheet>>,
    );
    fn exit_now(&mut self);
    fn collect_reports(
        &self,
        reports: &mut Vec<Report>,
        ops: &mut MallocSizeOfOps,
    );
    fn set_quirks_mode(&mut self, quirks_mode: QuirksMode);
    fn remove_stylesheet(&mut self, stylesheet: ServoArc<Stylesheet>);
    fn remove_cached_image(&mut self, image_url: &ServoUrl);
    fn reflow(&mut self, reflow_request: ReflowRequest) -> Option<ReflowResult>;
    fn ensure_stacking_context_tree(&self, viewport_details: ViewportDetails);
    fn register_paint_worklet_modules(
        &mut self,
        name: Atom,
        properties: Vec<Atom>,
        painter: Box<dyn Painter>,
    );
    fn set_scroll_offsets_from_renderer(
        &mut self,
        scroll_states: &FxHashMap<ExternalScrollId, LayoutVector2D>,
    );
    fn scroll_offset(&self, id: ExternalScrollId) -> Option<LayoutVector2D>;
    fn needs_new_display_list(&self) -> bool;
    fn set_needs_new_display_list(&self);
    fn node_rendering_type(
        &self,
        node: TrustedNodeAddress,
        pseudo: Option<PseudoElement>,
    ) -> NodeRenderingType;
    fn query_containing_block(
        &self,
        node: TrustedNodeAddress,
    ) -> Option<UntrustedNodeAddress>;
    fn query_containing_block_is_descendant(
        &self,
        root: TrustedNodeAddress,
        possible_descendant: TrustedNodeAddress,
    ) -> bool;
    fn query_padding(&self, node: TrustedNodeAddress) -> Option<PhysicalSides>;
    fn query_box_area(
        &self,
        node: TrustedNodeAddress,
        area: BoxAreaType,
        exclude_transform_and_inline: bool,
    ) -> Option<Rect<Au, CSSPixel>>;
    fn query_box_areas(
        &self,
        node: TrustedNodeAddress,
        area: BoxAreaType,
    ) -> CSSPixelRectVec;
    fn query_client_rect(&self, node: TrustedNodeAddress) -> Rect<i32, CSSPixel>;
    fn query_current_css_zoom(&self, node: TrustedNodeAddress) -> f32;
    fn query_element_inner_outer_text(&self, node: TrustedNodeAddress) -> String;
    fn query_offset_parent(
        &self,
        node: TrustedNodeAddress,
    ) -> OffsetParentResponse;
    fn query_scroll_container(
        &self,
        node: Option<TrustedNodeAddress>,
        flags: ScrollContainerQueryFlags,
    ) -> Option<ScrollContainerResponse>;
    fn query_resolved_style(
        &self,
        node: TrustedNodeAddress,
        pseudo: Option<PseudoElement>,
        property_id: PropertyId,
        animations: DocumentAnimationSet,
        animation_timeline_value: f64,
    ) -> String;
    fn query_resolved_font_style(
        &self,
        node: TrustedNodeAddress,
        value: &str,
        animations: DocumentAnimationSet,
        animation_timeline_value: f64,
    ) -> Option<ServoArc<Font>>;
    fn query_scrolling_area(
        &self,
        node: Option<TrustedNodeAddress>,
    ) -> Rect<i32, CSSPixel>;
    fn query_text_index(
        &self,
        node: TrustedNodeAddress,
        point: Point2D<Au, CSSPixel>,
    ) -> Option<usize>;
    fn query_elements_from_point(
        &self,
        point: LayoutPoint,
    ) -> Vec<ElementsFromPointResult>;
    fn query_effective_overflow(
        &self,
        node: TrustedNodeAddress,
    ) -> Option<AxesOverflow>;
    fn stylist_mut(&mut self) -> &mut Stylist;
    fn set_accessibility_active(&self, enabled: bool, epoch: Epoch);
    fn accessibility_active(&self) -> bool;
    fn needs_accessibility_update(&self) -> bool;
    fn set_needs_accessibility_update(&self);
}

Required Methods

fn device(&self) -> &Device

Get a reference to this Layout’s Stylo Device used to handle media queries and resolve font metrics.

fn set_theme(&mut self, theme: Theme) -> bool

Set the theme on this Layout’s Device. The caller should also trigger a new layout when this happens, though it can happen later. Returns true if the Theme actually changed or false otherwise.

fn set_viewport_details(&mut self, viewport_details: ViewportDetails) -> bool

Set the ViewportDetails on this Layout’s Device. The caller should also trigger a new layout when this happens, though it can happen later. Returns true if the ViewportDetails actually changed or false otherwise.

fn add_stylesheet( &mut self, stylesheet: ServoArc<Stylesheet>, before_stylesheet: Option<ServoArc<Stylesheet>>, )

Add a stylesheet to this Layout’s Stylist.

The second stylesheet is the insertion point (if it exists, the sheet needs to be inserted before it).

fn exit_now(&mut self)

Inform the layout that its ScriptThread is about to exit.

fn collect_reports(&self, reports: &mut Vec<Report>, ops: &mut MallocSizeOfOps)

Requests that layout measure its memory usage. The resulting reports are sent back via the supplied channel.

fn set_quirks_mode(&mut self, quirks_mode: QuirksMode)

Sets quirks mode for the document, causing the quirks mode stylesheet to be used.

fn remove_stylesheet(&mut self, stylesheet: ServoArc<Stylesheet>)

Removes a stylesheet from the Layout.

fn remove_cached_image(&mut self, image_url: &ServoUrl)

Removes an image from the Layout image resolver cache.

fn reflow(&mut self, reflow_request: ReflowRequest) -> Option<ReflowResult>

Requests a reflow.

fn ensure_stacking_context_tree(&self, viewport_details: ViewportDetails)

Do not request a reflow, but ensure that any previous reflow completes building a stacking context tree so that it is ready to query the final size of any elements in script.

fn register_paint_worklet_modules( &mut self, name: Atom, properties: Vec<Atom>, painter: Box<dyn Painter>, )

Tells layout that script has added some paint worklet modules.

fn set_scroll_offsets_from_renderer( &mut self, scroll_states: &FxHashMap<ExternalScrollId, LayoutVector2D>, )

Set the scroll states of this layout after a Paint scroll.

fn scroll_offset(&self, id: ExternalScrollId) -> Option<LayoutVector2D>

Get the scroll offset of the given scroll node with id of ExternalScrollId or None if it does not exist in the tree.

fn needs_new_display_list(&self) -> bool

Returns true if this layout needs to produce a new display list for rendering updates.

fn set_needs_new_display_list(&self)

Marks that this layout needs to produce a new display list for rendering updates.

fn node_rendering_type( &self, node: TrustedNodeAddress, pseudo: Option<PseudoElement>, ) -> NodeRenderingType

Returns the NodeRenderingType for this node and pseudo. This is used to determine if a node is being rendered, delegating its rendering, or not being rendered at all.

fn query_containing_block( &self, node: TrustedNodeAddress, ) -> Option<UntrustedNodeAddress>

fn query_containing_block_is_descendant( &self, root: TrustedNodeAddress, possible_descendant: TrustedNodeAddress, ) -> bool

fn query_padding(&self, node: TrustedNodeAddress) -> Option<PhysicalSides>

fn query_box_area( &self, node: TrustedNodeAddress, area: BoxAreaType, exclude_transform_and_inline: bool, ) -> Option<Rect<Au, CSSPixel>>

fn query_box_areas( &self, node: TrustedNodeAddress, area: BoxAreaType, ) -> CSSPixelRectVec

fn query_client_rect(&self, node: TrustedNodeAddress) -> Rect<i32, CSSPixel>

fn query_current_css_zoom(&self, node: TrustedNodeAddress) -> f32

fn query_element_inner_outer_text(&self, node: TrustedNodeAddress) -> String

fn query_offset_parent(&self, node: TrustedNodeAddress) -> OffsetParentResponse

fn query_scroll_container( &self, node: Option<TrustedNodeAddress>, flags: ScrollContainerQueryFlags, ) -> Option<ScrollContainerResponse>

Query the scroll container for the given node. If node is None, the scroll container for the viewport is returned.

fn query_resolved_style( &self, node: TrustedNodeAddress, pseudo: Option<PseudoElement>, property_id: PropertyId, animations: DocumentAnimationSet, animation_timeline_value: f64, ) -> String

fn query_resolved_font_style( &self, node: TrustedNodeAddress, value: &str, animations: DocumentAnimationSet, animation_timeline_value: f64, ) -> Option<ServoArc<Font>>

fn query_scrolling_area( &self, node: Option<TrustedNodeAddress>, ) -> Rect<i32, CSSPixel>

fn query_text_index( &self, node: TrustedNodeAddress, point: Point2D<Au, CSSPixel>, ) -> Option<usize>

Find the character offset of the point in the given node, if it has text content.

fn query_elements_from_point( &self, point: LayoutPoint, ) -> Vec<ElementsFromPointResult>

fn query_effective_overflow( &self, node: TrustedNodeAddress, ) -> Option<AxesOverflow>

fn stylist_mut(&mut self) -> &mut Stylist

fn set_accessibility_active(&self, enabled: bool, epoch: Epoch)

Set whether the accessibility tree should be constructed for this Layout. This should be called by the embedder when accessibility is requested by the user.

fn accessibility_active(&self) -> bool

Returns whether accessibility is active for this Layout.

fn needs_accessibility_update(&self) -> bool

Whether the accessibility tree needs updating. This is set to true when

• accessibility is activated; or
• a page is loaded after accesibility is activated.

In future, this should be set to true if DOM or style have changed in a way that impacts the accessibility tree.

Checked in can_skip_reflow_request_entirely(), as a dirty accessibility tree should force a reflow, and handle_reflow() to determine whether to update the accessibility tree during reflow.

fn set_needs_accessibility_update(&self)

See Self::needs_accessibility_update().

Implementors