Struct Preferences 

pub struct Preferences {

    pub fonts_default: String,
    pub fonts_serif: String,
    pub fonts_sans_serif: String,
    pub fonts_monospace: String,
    pub fonts_default_size: i64,
    pub fonts_default_monospace_size: i64,
    pub editing_caret_blink_time: i64,
    pub css_animations_testing_enabled: bool,
    pub devtools_server_enabled: bool,
    pub devtools_server_listen_address: String,
    pub dom_webgpu_enabled: bool,
    pub dom_webgpu_wgpu_backend: String,
    pub dom_abort_controller_enabled: bool,
    pub dom_adoptedstylesheet_enabled: bool,
    pub dom_allow_preloading_module_descendants: bool,
    pub dom_async_clipboard_enabled: bool,
    pub dom_bluetooth_enabled: bool,
    pub dom_bluetooth_testing_enabled: bool,
    pub dom_allow_scripts_to_close_windows: bool,
    pub dom_canvas_capture_enabled: bool,
    pub dom_canvas_text_enabled: bool,
    pub dom_canvas_backend: String,
    pub dom_clipboardevent_enabled: bool,
    pub dom_composition_event_enabled: bool,
    pub dom_cookiestore_enabled: bool,
    pub dom_credential_management_enabled: bool,
    pub dom_crypto_subtle_enabled: bool,
    pub dom_document_dblclick_timeout: i64,
    pub dom_document_dblclick_dist: i64,
    pub dom_exec_command_enabled: bool,
    pub dom_fontface_enabled: bool,
    pub dom_fullscreen_test: bool,
    pub dom_gamepad_enabled: bool,
    pub dom_geolocation_enabled: bool,
    pub dom_wakelock_enabled: bool,
    pub dom_indexeddb_enabled: bool,
    pub dom_intersection_observer_enabled: bool,
    pub dom_microdata_testing_enabled: bool,
    pub dom_uievent_which_enabled: bool,
    pub dom_mutation_observer_enabled: bool,
    pub dom_navigator_protocol_handlers_enabled: bool,
    pub dom_notification_enabled: bool,
    pub dom_offscreen_canvas_enabled: bool,
    pub dom_parallel_css_parsing_enabled: bool,
    pub dom_permissions_enabled: bool,
    pub dom_permissions_testing_allowed_in_nonsecure_contexts: bool,
    pub dom_resize_observer_enabled: bool,
    pub dom_sanitizer_enabled: bool,
    pub dom_script_asynch: bool,
    pub dom_storage_manager_api_enabled: bool,
    pub dom_serviceworker_enabled: bool,
    pub dom_serviceworker_timeout_seconds: i64,
    pub dom_sharedworker_enabled: bool,
    pub dom_servo_helpers_enabled: bool,
    pub dom_servoparser_async_html_tokenizer_enabled: bool,
    pub dom_testbinding_enabled: bool,
    pub dom_testbinding_prefcontrolled_enabled: bool,
    pub dom_testbinding_prefcontrolled2_enabled: bool,
    pub dom_testbinding_preference_value_falsy: bool,
    pub dom_testbinding_preference_value_quote_string_test: String,
    pub dom_testbinding_preference_value_space_string_test: String,
    pub dom_testbinding_preference_value_string_empty: String,
    pub dom_testbinding_preference_value_string_test: String,
    pub dom_testbinding_preference_value_truthy: bool,
    pub dom_testing_element_activation_enabled: bool,
    pub dom_testing_html_input_element_select_files_enabled: bool,
    pub dom_testperf_enabled: bool,
    pub dom_testutils_enabled: bool,
    pub dom_transient_activation_duration_ms: i64,
    pub dom_webgl2_enabled: bool,
    pub dom_webrtc_enabled: bool,
    pub dom_webrtc_transceiver_enabled: bool,
    pub dom_webvtt_enabled: bool,
    pub dom_webxr_enabled: bool,
    pub dom_webxr_test: bool,
    pub dom_webxr_first_person_observer_view: bool,
    pub dom_webxr_glwindow_enabled: bool,
    pub dom_webxr_glwindow_left_right: bool,
    pub dom_webxr_glwindow_red_cyan: bool,
    pub dom_webxr_glwindow_spherical: bool,
    pub dom_webxr_glwindow_cubemap: bool,
    pub dom_webxr_hands_enabled: bool,
    pub dom_webxr_layers_enabled: bool,
    pub dom_webxr_openxr_enabled: bool,
    pub dom_webxr_sessionavailable: bool,
    pub dom_webxr_unsafe_assume_user_intent: bool,
    pub dom_worklet_enabled: bool,
    pub dom_worklet_blockingsleep_enabled: bool,
    pub dom_worklet_testing_enabled: bool,
    pub dom_worklet_timeout_ms: i64,
    pub dom_visual_viewport_enabled: bool,
    pub gfx_precache_shaders: bool,
    pub gfx_text_antialiasing_enabled: bool,
    pub gfx_subpixel_text_antialiasing_enabled: bool,
    pub gfx_texture_swizzling_enabled: bool,
    pub image_key_batch_size: i64,
    pub inspector_show_servo_internal_shadow_roots: bool,
    pub intl_locale_override: String,
    pub js_asmjs_enabled: bool,
    pub js_baseline_interpreter_enabled: bool,
    pub js_disable_jit: bool,
    pub js_baseline_jit_enabled: bool,
    pub js_baseline_jit_unsafe_eager_compilation_enabled: bool,
    pub js_ion_enabled: bool,
    pub js_ion_unsafe_eager_compilation_enabled: bool,
    pub js_mem_gc_compacting_enabled: bool,
    pub js_mem_gc_empty_chunk_count_min: i64,
    pub js_mem_gc_high_frequency_heap_growth_max: i64,
    pub js_mem_gc_high_frequency_heap_growth_min: i64,
    pub js_mem_gc_high_frequency_high_limit_mb: i64,
    pub js_mem_gc_high_frequency_low_limit_mb: i64,
    pub js_mem_gc_high_frequency_time_limit_ms: i64,
    pub js_mem_gc_incremental_enabled: bool,
    pub js_mem_gc_incremental_slice_ms: i64,
    pub js_mem_gc_low_frequency_heap_growth: i64,
    pub js_mem_gc_per_zone_enabled: bool,
    pub js_mem_gc_zeal_frequency: i64,
    pub js_mem_gc_zeal_level: i64,
    pub js_mem_max: i64,
    pub js_native_regex_enabled: bool,
    pub js_offthread_compilation_enabled: bool,
    pub js_timers_minimum_duration: i64,
    pub js_wasm_baseline_enabled: bool,
    pub js_wasm_enabled: bool,
    pub js_wasm_ion_enabled: bool,
    pub largest_contentful_paint_enabled: bool,
    pub layout_animations_test_enabled: bool,
    pub layout_columns_enabled: bool,
    pub layout_grid_enabled: bool,
    pub layout_container_queries_enabled: bool,
    pub layout_css_attr_enabled: bool,
    pub layout_style_sharing_cache_enabled: bool,
    pub layout_threads: i64,
    pub layout_unimplemented: bool,
    pub layout_variable_fonts_enabled: bool,
    pub layout_writing_mode_enabled: bool,
    pub media_glvideo_enabled: bool,
    pub media_testing_enabled: bool,
    pub network_connection_timeout: u64,
    pub network_enforce_tls_enabled: bool,
    pub network_enforce_tls_localhost: bool,
    pub network_enforce_tls_onion: bool,
    pub network_http_cache_disabled: bool,
    pub network_http_proxy_uri: String,
    pub network_https_proxy_uri: String,
    pub network_http_no_proxy: String,
    pub network_http_cache_size: u64,
    pub network_local_directory_listing_enabled: bool,
    pub network_use_webpki_roots: bool,
    pub session_history_max_length: i64,
    pub shell_background_color_rgba: [f64; 4],
    pub webgl_testing_context_creation_error: bool,
    pub thread_pool_workers_max: u64,
    pub thread_pool_fallback_workers: u64,
    pub thread_pool_async_runtime_workers_max: u64,
    pub thread_pool_webrender_workers_max: u64,
    pub user_agent: String,
    pub viewport_meta_enabled: bool,
    pub log_filter: String,
    pub accessibility_enabled: bool,
}

The set of global preferences supported by Servo.

Each preference has a default value that determines its initial state. These defaults fall into roughly three categories:

• Stable: enabled by default.
• Experimental: disabled by default, but intended to be enabled for experimental use.
• Unstable: disabled by default.

For a full overview of which preferences are experimental, see the experimental features documentation.

Fields

fonts_default: String

fonts_serif: String

fonts_sans_serif: String

fonts_monospace: String

fonts_default_size: i64

fonts_default_monospace_size: i64

editing_caret_blink_time: i64

The amount of time that a half cycle of a text caret blink takes in milliseconds. If this value is less than or equal to zero, then caret blink is disabled.

css_animations_testing_enabled: bool

devtools_server_enabled: bool

Start the devtools server at startup

devtools_server_listen_address: String

The address:port the devtools server listens to, default to 127.0.0.1:7000.

dom_webgpu_enabled: bool

dom_webgpu_wgpu_backend: String

List of comma-separated backends to be used by wgpu.

dom_abort_controller_enabled: bool

dom_adoptedstylesheet_enabled: bool

dom_allow_preloading_module_descendants: bool

dom_async_clipboard_enabled: bool

dom_bluetooth_enabled: bool

dom_bluetooth_testing_enabled: bool

dom_allow_scripts_to_close_windows: bool

dom_canvas_capture_enabled: bool

dom_canvas_text_enabled: bool

dom_canvas_backend: String

Selects canvas backend

Available values:

• /auto
• vello
• vello_cpu

dom_clipboardevent_enabled: bool

dom_composition_event_enabled: bool

dom_cookiestore_enabled: bool

dom_credential_management_enabled: bool

dom_crypto_subtle_enabled: bool

dom_document_dblclick_timeout: i64

dom_document_dblclick_dist: i64

dom_exec_command_enabled: bool

dom_fontface_enabled: bool

dom_fullscreen_test: bool

dom_gamepad_enabled: bool

dom_geolocation_enabled: bool

dom_wakelock_enabled: bool

dom_indexeddb_enabled: bool

dom_intersection_observer_enabled: bool

dom_microdata_testing_enabled: bool

dom_uievent_which_enabled: bool

dom_mutation_observer_enabled: bool

dom_navigator_protocol_handlers_enabled: bool

dom_notification_enabled: bool

dom_offscreen_canvas_enabled: bool

dom_parallel_css_parsing_enabled: bool

dom_permissions_enabled: bool

dom_permissions_testing_allowed_in_nonsecure_contexts: bool

dom_resize_observer_enabled: bool

dom_sanitizer_enabled: bool

dom_script_asynch: bool

dom_storage_manager_api_enabled: bool

dom_serviceworker_enabled: bool

dom_serviceworker_timeout_seconds: i64

dom_sharedworker_enabled: bool

dom_servo_helpers_enabled: bool

dom_servoparser_async_html_tokenizer_enabled: bool

dom_testbinding_enabled: bool

dom_testbinding_prefcontrolled_enabled: bool

dom_testbinding_prefcontrolled2_enabled: bool

dom_testbinding_preference_value_falsy: bool

dom_testbinding_preference_value_quote_string_test: String

dom_testbinding_preference_value_space_string_test: String

dom_testbinding_preference_value_string_empty: String

dom_testbinding_preference_value_string_test: String

dom_testbinding_preference_value_truthy: bool

dom_testing_element_activation_enabled: bool

dom_testing_html_input_element_select_files_enabled: bool

dom_testperf_enabled: bool

dom_testutils_enabled: bool

dom_transient_activation_duration_ms: i64

https://html.spec.whatwg.org/multipage/#transient-activation-duration

dom_webgl2_enabled: bool

Enable WebGL2 APIs.

dom_webrtc_enabled: bool

dom_webrtc_transceiver_enabled: bool

dom_webvtt_enabled: bool

dom_webxr_enabled: bool

dom_webxr_test: bool

dom_webxr_first_person_observer_view: bool

dom_webxr_glwindow_enabled: bool

dom_webxr_glwindow_left_right: bool

dom_webxr_glwindow_red_cyan: bool

dom_webxr_glwindow_spherical: bool

dom_webxr_glwindow_cubemap: bool

dom_webxr_hands_enabled: bool

dom_webxr_layers_enabled: bool

dom_webxr_openxr_enabled: bool

dom_webxr_sessionavailable: bool

dom_webxr_unsafe_assume_user_intent: bool

dom_worklet_enabled: bool

dom_worklet_blockingsleep_enabled: bool

dom_worklet_testing_enabled: bool

dom_worklet_timeout_ms: i64

dom_visual_viewport_enabled: bool

https://drafts.csswg.org/cssom-view/#the-visualviewport-interface

gfx_precache_shaders: bool

True to compile all WebRender shaders when Servo initializes. This is mostly useful when modifying the shaders, to ensure they all compile after each change is made.

gfx_text_antialiasing_enabled: bool

Whether or not antialiasing is enabled for text rendering.

gfx_subpixel_text_antialiasing_enabled: bool

Whether or not subpixel antialiasing is enabled for text rendering.

gfx_texture_swizzling_enabled: bool

image_key_batch_size: i64

The amount of image keys we request per batch for the image cache.

inspector_show_servo_internal_shadow_roots: bool

Whether or not the DOM inspector should show shadow roots of user-agent shadow trees

intl_locale_override: String

A locale tag (eg. es-ES) to use for language negotiation instead of the system locale. An empty string represents no override. TODO: Option<> support in PrefValue

js_asmjs_enabled: bool

js_baseline_interpreter_enabled: bool

js_disable_jit: bool

Whether to disable the jit within SpiderMonkey

js_baseline_jit_enabled: bool

js_baseline_jit_unsafe_eager_compilation_enabled: bool

js_ion_enabled: bool

js_ion_unsafe_eager_compilation_enabled: bool

js_mem_gc_compacting_enabled: bool

js_mem_gc_empty_chunk_count_min: i64

js_mem_gc_high_frequency_heap_growth_max: i64

js_mem_gc_high_frequency_heap_growth_min: i64

js_mem_gc_high_frequency_high_limit_mb: i64

js_mem_gc_high_frequency_low_limit_mb: i64

js_mem_gc_high_frequency_time_limit_ms: i64

js_mem_gc_incremental_enabled: bool

js_mem_gc_incremental_slice_ms: i64

js_mem_gc_low_frequency_heap_growth: i64

js_mem_gc_per_zone_enabled: bool

js_mem_gc_zeal_frequency: i64

js_mem_gc_zeal_level: i64

js_mem_max: i64

js_native_regex_enabled: bool

js_offthread_compilation_enabled: bool

js_timers_minimum_duration: i64

js_wasm_baseline_enabled: bool

js_wasm_enabled: bool

js_wasm_ion_enabled: bool

largest_contentful_paint_enabled: bool

layout_animations_test_enabled: bool

layout_columns_enabled: bool

layout_grid_enabled: bool

layout_container_queries_enabled: bool

layout_css_attr_enabled: bool

layout_style_sharing_cache_enabled: bool

layout_threads: i64

layout_unimplemented: bool

layout_variable_fonts_enabled: bool

layout_writing_mode_enabled: bool

media_glvideo_enabled: bool

Enable hardware acceleration for video playback.

media_testing_enabled: bool

Enable a non-standard event handler for verifying behavior of media elements during tests.

network_connection_timeout: u64

The default timeout set for establishing a network connection in seconds. This amount if for the entire process of connecting to an address. For instance, if a particular host is associated with multiple IP addresses, this timeout will be divided equally among each IP address.

network_enforce_tls_enabled: bool

network_enforce_tls_localhost: bool

network_enforce_tls_onion: bool

network_http_cache_disabled: bool

network_http_proxy_uri: String

A url for a http proxy. We treat an empty string as no proxy.

network_https_proxy_uri: String

A url for a https proxy. We treat an empty string as no proxy.

network_http_no_proxy: String

The domains for which we will not have a proxy. No effect if network_http_proxy_uri is not set. The exact behavior is given by https://docs.rs/hyper-util/latest/hyper_util/client/proxy/matcher/struct.Builder.html#method.no

network_http_cache_size: u64

The weight of the http memory cache Notice that this is not equal to the number of different urls in the cache.

network_local_directory_listing_enabled: bool

network_use_webpki_roots: bool

Force the use of rust-webpki verification for CA roots. If this is false (the default), then rustls-platform-verifier will be used, except on Android where rust-webpki is always used.

session_history_max_length: i64

The length of the session history, in navigations, for each WebView. Back-forward cache entries that are more than session_history_max_lengthsteps in the future orsession_history_max_length` steps in the past will be discarded. Navigating forward or backward to that entry will cause the entire page to be reloaded.

shell_background_color_rgba: [f64; 4]

The background color of shell’s viewport. This will be used by OpenGL’s glClearColor.

webgl_testing_context_creation_error: bool

thread_pool_workers_max: u64

Maximum number of workers for the main thread pool

thread_pool_fallback_workers: u64

Number of workers per thread pool, if we fail to detect how much parallelism is available at runtime.

thread_pool_async_runtime_workers_max: u64

Maximum number of workers for the asynchronous networking runtime thread pool

thread_pool_webrender_workers_max: u64

Maximum number of workers for WebRender

user_agent: String

The user-agent to use for Servo. This can also be set via UserAgentPlatform in order to set the value to the default value for the given platform.

viewport_meta_enabled: bool

Whether or not the viewport meta tag is enabled.

log_filter: String

accessibility_enabled: bool

Whether the accessibility code is enabled.

Implementations

impl Preferences

pub fn exists(name: &str) -> bool

pub fn get_value(&self, name: &str) -> PrefValue

pub fn set_value(&mut self, name: &str, value: PrefValue)

pub fn type_of(name: &str) -> &'static str

pub fn diff(&self, other: &Preferences) -> Vec<(&'static str, PrefValue)>

pub fn all_fields() -> Vec<&'static str>

impl Preferences

pub fn editing_caret_blink_time(&self) -> Option<Duration>

The amount of time that a half cycle of a text caret blink takes. If blinking is disabled this returns None.

Trait Implementations

impl Clone for Preferences

fn clone(&self) -> Preferences

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Default for Preferences

fn default() -> Preferences

Returns the “default value” for a type.

impl<'de> Deserialize<'de> for Preferences

fn deserialize<__D>( __deserializer: __D, ) -> Result<Preferences, <__D as Deserializer<'de>>::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Serialize for Preferences

fn serialize<__S>( &self, __serializer: __S, ) -> Result<<__S as Serializer>::Ok, <__S as Serializer>::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.