Trait RendererSealed

pub trait RendererSealed {
    // Required methods
    fn text_size(
        &self,
        font_request: FontRequest,
        text: &str,
        max_width: Option<LogicalLength>,
        scale_factor: ScaleFactor,
        text_wrap: TextWrap,
    ) -> LogicalSize;
    fn font_metrics(
        &self,
        font_request: FontRequest,
        scale_factor: ScaleFactor,
    ) -> FontMetrics;
    fn text_input_byte_offset_for_position(
        &self,
        text_input: Pin<&TextInput>,
        pos: LogicalPoint,
        font_request: FontRequest,
        scale_factor: ScaleFactor,
    ) -> usize;
    fn text_input_cursor_rect_for_byte_offset(
        &self,
        text_input: Pin<&TextInput>,
        byte_offset: usize,
        font_request: FontRequest,
        scale_factor: ScaleFactor,
    ) -> LogicalRect;
    fn default_font_size(&self) -> LogicalLength;
    fn set_window_adapter(&self, _window_adapter: &Rc<dyn WindowAdapter>);

    // Provided methods
    fn free_graphics_resources(
        &self,
        _component: ItemTreeRef<'_>,
        _items: &mut dyn Iterator<Item = Pin<ItemRef<'_>>>,
    ) -> Result<(), PlatformError> { ... }
    fn mark_dirty_region(&self, _region: DirtyRegion) { ... }
    fn register_font_from_memory(
        &self,
        _data: &'static [u8],
    ) -> Result<(), Box<dyn Error>> { ... }
    fn register_font_from_path(
        &self,
        _path: &Path,
    ) -> Result<(), Box<dyn Error>> { ... }
    fn register_bitmap_font(&self, _font_data: &'static BitmapFont) { ... }
    fn set_rendering_notifier(
        &self,
        _callback: Box<dyn RenderingNotifier>,
    ) -> Result<(), SetRenderingNotifierError> { ... }
    fn resize(&self, _size: PhysicalSize) -> Result<(), PlatformError> { ... }
    fn take_snapshot(
        &self,
    ) -> Result<SharedPixelBuffer<Rgba8Pixel>, PlatformError> { ... }
}

Implementation details behind Renderer, but since this trait is not exported in the public API, it is not possible for the users to re-implement these functions.

Required Methods

fn text_size( &self, font_request: FontRequest, text: &str, max_width: Option<LogicalLength>, scale_factor: ScaleFactor, text_wrap: TextWrap, ) -> LogicalSize

Returns the size of the given text in logical pixels. When set, max_width means that one need to wrap the text, so it does not go further than that, using the wrapping type passed by text_wrap.

fn font_metrics( &self, font_request: FontRequest, scale_factor: ScaleFactor, ) -> FontMetrics

Returns the metrics of the given font.

fn text_input_byte_offset_for_position( &self, text_input: Pin<&TextInput>, pos: LogicalPoint, font_request: FontRequest, scale_factor: ScaleFactor, ) -> usize

Returns the (UTF-8) byte offset in the text property that refers to the character that contributed to the glyph cluster that’s visually nearest to the given coordinate. This is used for hit-testing, for example when receiving a mouse click into a text field. Then this function returns the “cursor” position.

fn text_input_cursor_rect_for_byte_offset( &self, text_input: Pin<&TextInput>, byte_offset: usize, font_request: FontRequest, scale_factor: ScaleFactor, ) -> LogicalRect

That’s the opposite of Self::text_input_byte_offset_for_position It takes a (UTF-8) byte offset in the text property, and returns a Rectangle left to the char. It is one logical pixel wide and ends at the baseline.

fn default_font_size(&self) -> LogicalLength

fn set_window_adapter(&self, _window_adapter: &Rc<dyn WindowAdapter>)

Provided Methods

fn free_graphics_resources( &self, _component: ItemTreeRef<'_>, _items: &mut dyn Iterator<Item = Pin<ItemRef<'_>>>, ) -> Result<(), PlatformError>

Clear the caches for the items that are being removed

fn mark_dirty_region(&self, _region: DirtyRegion)

Mark a given region as dirty regardless whether the items actually are dirty.

Example: when a PopupWindow disappears, the region under the popup needs to be redrawn

fn register_font_from_memory( &self, _data: &'static [u8], ) -> Result<(), Box<dyn Error>>

This function can be used to register a custom TrueType font with Slint, for use with the font-family property. The provided slice must be a valid TrueType font.

fn register_font_from_path(&self, _path: &Path) -> Result<(), Box<dyn Error>>

This function can be used to register a custom TrueType font with Slint, for use with the font-family property. The provided path must refer to a valid TrueType font.

fn register_bitmap_font(&self, _font_data: &'static BitmapFont)

fn set_rendering_notifier( &self, _callback: Box<dyn RenderingNotifier>, ) -> Result<(), SetRenderingNotifierError>

This function is called through the public API to register a callback that the backend needs to invoke during different phases of rendering.

fn resize(&self, _size: PhysicalSize) -> Result<(), PlatformError>

fn take_snapshot(&self) -> Result<SharedPixelBuffer<Rgba8Pixel>, PlatformError>

Re-implement this function to support Window::take_snapshot(), i.e. return the contents of the window in an image buffer.

Implementors