Struct conrod::Ui [−] [src]

pub struct Ui<C> {
    pub theme: Theme,
    pub glyph_cache: GlyphCache<C>,
    pub win_w: f64,
    pub win_h: f64,
    // some fields omitted
}

Ui is the most important type within Conrod and is necessary for rendering and maintaining widget state.

Ui Handles the following:

  • Contains the state of all widgets which can be indexed via their widget::Index.
  • Stores rendering state for each widget until the end of each render cycle.
  • Contains the theme used for default styling of the widgets.
  • Maintains the latest user input state (for mouse and keyboard).
  • Maintains the latest window dimensions.

Fields

theme: Theme

The theme used to set default styling for widgets.

glyph_cache: GlyphCache<C>

Cache for character textures, used for label width calculation and glyph rendering.

win_w: f64

Window width.

win_h: f64

Window height.

Methods

impl<C> Ui<C>
[src]

fn new(character_cache: C, theme: Theme) -> Ui<C>

Constructor for a UiContext.

fn widget_size(&self, id: Id) -> Dimensions

Return the dimensions of a widget.

fn maybe_prev_widget(&self) -> Option<Index>

An index to the previously updated widget if there is one.

fn handle_event<E: GenericEvent>(&mut self, event: &E)

Handle game events and update the state.

fn get_xy(&self, maybe_idx: Option<Index>, position: Position, dim: Dimensions, h_align: HorizontalAlign, v_align: VerticalAlign) -> Point

Get the centred xy coords for some given Dimensions, Position and alignment. If getting the xy for a widget, its ID should be specified so that we can also consider the scroll offset of the scrollable parent widgets.

fn set_num_redraw_frames(&mut self, num_frames: u8)

Set the number of frames that the Ui should draw in the case that needs_redraw is called. The default is 3 (see the SAFE_REDRAW_COUNT docs for details).

fn needs_redraw(&mut self)

Tells the Ui that it needs to be re-draw everything. It does this by setting the redraw count to num_redraw_frames. See the docs for set_num_redraw_frames, SAFE_REDRAW_COUNT or draw_if_changed for more info on how/why the redraw count is used.

fn element(&mut self) -> &Element

Compiles the Ui's entire widget Graph in its current state into a single elmesque::Element and returns a reference to it.

This allows a user to take all information necessary for drawing within a single type, which can be sent across threads or used to draw later on rather than drawing the whole graph immediately (as does the Ui::draw method).

Producing an Element also allows for simpler interoperation with elmesque (a purely functional graphics layout crate which conrod uses internally).

fn element_if_changed(&mut self) -> Option<&Element>

Same as Ui::element, but only returns an &Element if the stored &Element has changed since the last time Ui::element or Ui::element_if_changed was called.

fn draw<G>(&mut self, context: Context, graphics: &mut G) where C: CharacterCache, G: Graphics<Texture=C::Texture>

Draw the Ui in it's current state. NOTE: If you don't need to redraw your conrod GUI every frame, it is recommended to use the Ui::draw_if_changed method instead. See the Graph::draw method for more details on how Widgets are drawn. See the graph::update_visit_order function for details on how the render order is determined.

fn draw_if_changed<G>(&mut self, context: Context, graphics: &mut G) where C: CharacterCache, G: Graphics<Texture=C::Texture>

Same as the Ui::draw method, but only draws if the redraw_count is greater than 0. The redraw_count is set to SAFE_REDRAW_COUNT whenever a Widget produces a new Element because its state has changed. It can also be triggered manually by the user using the Ui::needs_redraw method.

This method is generally preferred over Ui::draw as it requires far less CPU usage, only redrawing to the screen if necessary.

Note that when Ui::needs_redraw is triggered, it sets the redraw_count to 3 by default. This ensures that conrod is drawn to each buffer in the case that there is buffer swapping happening. Let us know if you need finer control over this and we'll expose a way for you to set the redraw count manually.

fn kids_bounding_box<I: Into<Index>>(&self, idx: I) -> Option<Rect>

The Rect that bounds the kids of the widget with the given index.

fn visible_area<I: Into<Index>>(&self, idx: I) -> Option<Rect>

The Rect that represents the maximum fully visible area for the widget with the given index, including consideration of cropped scroll area.

Otherwise, return None if the widget is not visible.