repo_description: Slint is an open-source declarative GUI toolkit to build native user interfaces for Rust, C++, JavaScript, or Python apps.
repo_topics: cpp declarative-ui desktop embedded-devices gui javascript language lsp-server native rust rust-lang toolkit ui user-interface wasm webassembly widgets
code: // Copyright © SixtyFPS GmbH <[REDACTED_EMAIL]>
  // SPDX-License-Identifier: GPL-3.0-only OR LicenseRef-Slint-Royalty-free-2.0 OR LicenseRef-Slint-Software-3.0
  
  use crate::Property;
  use crate::api::PlatformError;
  use crate::input::InternalKeyboardModifierState;
  use crate::platform::{EventLoopProxy, Platform};
  use alloc::boxed::Box;
  use alloc::rc::Rc;
  use core::cell::Cell;
  
  crate::thread_local! {
      pub(crate) static GLOBAL_CONTEXT : once_cell::unsync::OnceCell<SlintContext>
          = const { once_cell::unsync::OnceCell::new() }
  }
  
  pub(crate) struct SlintContextInner {
      platform: Box<dyn Platform>,
      pub(crate) window_count: core::cell::RefCell<isize>,
      /// This property is read by all translations, and marked dirty when the language changes,
      /// so that every translated string gets re-translated. The property's value is the current selected
      /// language when bundling translations.
      pub(crate) translations_dirty: core::pin::Pin<Box<Property<usize>>>,
      pub(crate) translations_bundle_languages:
          core::cell::RefCell<Option<alloc::vec::Vec<&'static str>>>,
      pub(crate) window_shown_hook:
          core::cell::RefCell<Option<Box<dyn FnMut(&Rc<dyn crate::platform::WindowAdapter>)>>>,
      #[cfg(all(unix, not(target_os = "macos")))]
      xdg_app_id: core::cell::RefCell<Option<crate::SharedString>>,
      #[cfg(feature = "tr")]
      external_translator: core::cell::RefCell<Option<Box<dyn tr::Translator>>>,
      #[cfg(feature = "shared-parley")]
      pub(crate) font_context: core::cell::RefCell<parley::FontContext>,
      #[cfg(feature = "shared-swash")]
      pub(crate) swash_scale_context: core::cell::RefCell<swash::scale::ScaleContext>,
      pub(crate) modifiers: Cell<InternalKeyboardModifierState>,
  }
  
  /// This context is meant to hold the state and the backend.
  /// Currently it is not possible to have several platform at the same time in one process, but in the future it might be.
  /// See issue #4294
  #[derive(Clone)]
  pub struct SlintContext(pub(crate) Rc<SlintContextInner>);
  
  impl SlintContext {
      /// Create a new context with a given platform
      pub fn new(platform: Box<dyn Platform + 'static>) -> Self {
          #[cfg(feature = "shared-parley")]
          let collection = i_slint_common::sharedfontique::create_collection(true);
  
          Self(Rc::new(SlintContextInner {
              platform,
              window_count: 0.into(),
              translations_dirty: Box::pin(Property::new_named(0, "SlintContext::translations")),
              translations_bundle_languages: Default::default(),
              window_shown_hook: Default::default(),
              #[cfg(all(unix, not(target_os = "macos")))]
              xdg_app_id: Default::default(),
              #[cfg(feature = "tr")]
              external_translator: Default::default(),
              #[cfg(feature = "shared-parley")]
              font_context: {
                  let font_context = parley::FontContext {
                      collection: collection.inner,
                      source_cache: collection.source_cache,
                  };
                  core::cell::RefCell::new(font_context)
              },
              #[cfg(feature = "shared-swash")]
              swash_scale_context: core::cell::RefCell::new(swash::scale::ScaleContext::new()),
              modifiers: Cell::new(Default::default()),
          }))
      }
  
      /// Return a reference to the platform abstraction
      pub fn platform(&self) -> &dyn Platform {
          &*self.0.platform
      }
  
      /// Return a reference to the font context
      #[cfg(feature = "shared-parley")]
      pub fn font_context(&self) -> &core::cell::RefCell<parley::FontContext> {
          &self.0.font_context
      }
  
      /// Return a reference to the swash scale context
      #[cfg(feature = "shared-swash")]
      pub fn swash_scale_context(&self) -> &core::cell::RefCell<swash::scale::ScaleContext> {
          &self.0.swash_scale_context
      }
  
      /// Return an event proxy
      // FIXME: Make EvenLoopProxy cloneable, and maybe wrap in a struct
      pub fn event_loop_proxy(&self) -> Option<Box<dyn EventLoopProxy>> {
          self.0.platform.new_event_loop_proxy()
      }
  
      #[cfg(target_has_atomic = "ptr")]
      /// Context specific version of `slint::spawn_local`
      pub fn spawn_local<F: core::future::Future + 'static>(
          &self,
          fut: F,
      ) -> Result<crate::future::JoinHandle<F::Output>, crate::api::EventLoopError> {
          crate::future::spawn_local_with_ctx(self, fut)
      }
  
      pub fn run_event_loop(&self) -> Result<(), PlatformError> {
          self.0.platform.run_event_loop()
      }
  
      pub fn set_xdg_app_id(&self, _app_id: crate::SharedString) {
          #[cfg(all(unix, not(target_os = "macos")))]
          {
              self.0.xdg_app_id.replace(Some(_app_id));
          }
      }
  
      #[cfg(all(unix, not(target_os = "macos")))]
      pub fn xdg_app_id(&self) -> Option<crate::SharedString> {
          self.0.xdg_app_id.borrow().clone()
      }
  
      #[cfg(not(all(unix, not(target_os = "macos"))))]
      pub fn xdg_app_id(&self) -> Option<crate::SharedString> {
          None
      }
  
      #[cfg(feature = "tr")]
      pub fn set_external_translator(&self, translator: Option<Box<dyn tr::Translator>>) {
          *self.0.external_translator.borrow_mut() = translator;
          self.0.translations_dirty.mark_dirty();
      }
  
      #[cfg(feature = "tr")]
      pub fn external_translator(&self) -> Option<core::cell::Ref<'_, Box<dyn tr::Translator>>> {
          core::cell::Ref::filter_map(self.0.external_translator.borrow(), |maybe_translator| {
              maybe_translator.as_ref()
          })
          .ok()
      }
  }
  
  /// Internal function to access the context.
  /// The factory function is called if the platform abstraction is not yet
  /// initialized, and should be given by the platform_selector
  pub fn with_global_context<R>(
      factory: impl FnOnce() -> Result<Box<dyn Platform + 'static>, PlatformError>,
      f: impl FnOnce(&SlintContext) -> R,
  ) -> Result<R, PlatformError> {
      GLOBAL_CONTEXT.with(|p| match p.get() {
          Some(ctx) => Ok(f(ctx)),
          None => {
              if crate::platform::with_event_loop_proxy(|proxy| proxy.is_some()) {
                  return Err(PlatformError::SetPlatformError(
                      crate::platform::SetPlatformError::AlreadySet,
                  ));
              }
              crate::platform::set_platform(factory()?).map_err(PlatformError::SetPlatformError)?;
              Ok(f(p.get().unwrap()))
          }
      })
  }
  
  /// Internal function to set a hook that's invoked whenever a slint::Window is shown. This
  /// is used by the system testing module. Returns a previously set hook, if any.
  pub fn set_window_shown_hook(
      hook: Option<Box<dyn FnMut(&Rc<dyn crate::platform::WindowAdapter>)>>,
  ) -> Result<Option<Box<dyn FnMut(&Rc<dyn crate::platform::WindowAdapter>)>>, PlatformError> {
      GLOBAL_CONTEXT.with(|p| match p.get() {
          Some(ctx) => Ok(ctx.0.window_shown_hook.replace(hook)),
          None => Err(PlatformError::NoPlatform),
      })
  }
  