src/plugins/dialogueview/mod.rs

//! A dialogue view for Yarn Spinner.
//!
//! A dialogue view is a plugin that handles presenting lines and options to the user and advances the dialogue on user input.
//!
//! This crate also exposes the [`SpeakerChangeEvent`] which you can use to animate characters while they are speaking,
//! as the text is written out over a few seconds.
//!
//! ## Inputs
//!
//! - Advance the dialogue: press the space bar, enter key, left click or tap the screen after the text is done typing.
//! - Type out the text faster: Same as above, but hold press before the text is done typing.
//! - Select an option: press the number key corresponding to the option you want to select or click/tap the option.
//!
//! ## Limitations
//!
//! This dialogue view expects only a single instance of [`DialogueRunner`](bevy_yarnspinner::prelude::DialogueRunner) to be running.
//! Its behavior is otherwise undefined.

mod option_selection;
mod setup;
mod typewriter;
mod updating;

use bevy::{
    app::{ App, Plugin, Update },
    asset::Handle,
    ecs::{
        schedule::{ common_conditions::resource_added, Condition, IntoSystemConfigs, SystemSet },
        system::{ Commands, Res, Resource },
    },
    log::info,
    render::texture::Image,
    state::{ condition::in_state, state::{ FreelyMutableState, States } },
    text::Font,
};
use bevy_asset_loader::{
    asset_collection::AssetCollection,
    loading_state::{ config::{ ConfigureLoadingState, LoadingStateConfig }, LoadingStateAppExt },
};
use bevy_yarnspinner::prelude::{ YarnFileSource, YarnSpinnerPlugin, YarnProject };

pub use updating::SpeakerChangeEvent;
pub(crate) use typewriter::not_in_dialogue;

/// The plugin registering all systems of the dialogue view.
#[derive(Debug, Default)]
pub struct YarnSpinnerDialogueViewPlugin<T> {
    /// Assets loading will be added to this loading state
    pub loading_state: T,
    /// Dialogue view will be spawn when transitioning to this state
    pub playing_state: T,
}

/// The [`SystemSet`] containing all systems added by the [`YarnSpinnerDialogueViewPlugin`].
/// Is run after the [`YarnSpinnerSystemSet`](bevy_yarnspinner::prelude::YarnSpinnerSystemSet).
#[derive(Debug, Default, Clone, Copy, SystemSet, Eq, PartialEq, Hash)]
pub struct YarnSpinnerDialogueViewSystemSet;

#[derive(AssetCollection, Resource)]
struct Assets {
    #[asset(path = "fonts/bahnschrift.ttf")]
    font: Handle<Font>,
    #[asset(path = "ui/dialogue_continue.png")]
    continue_indicator: Handle<Image>,
    #[asset(path = "ui/dialogue_edge.png")]
    edge: Handle<Image>,
}

impl<T: States + FreelyMutableState> Plugin for YarnSpinnerDialogueViewPlugin<T> {
    fn build(&self, app: &mut App) {
        app.add_plugins(
            YarnSpinnerPlugin::with_yarn_source(YarnFileSource::file("dialogues/kade_dialog.yarn"))
        )
            .configure_loading_state(
                LoadingStateConfig::new(self.loading_state.clone()).load_collection::<Assets>()
            )
            .add_systems(Update, setup::setup.run_if(resource_added::<Assets>))
            .add_plugins(updating::ui_updating_plugin)
            .add_plugins(typewriter::typewriter_plugin)
            .add_plugins(option_selection::option_selection_plugin)
            .add_systems(
                Update,
                // Spawn the dialogue runner once the Yarn project has finished compiling
                spawn_dialogue_runner.run_if(
                    in_state(self.playing_state.clone()).and_then(resource_added::<YarnProject>)
                )
            );
    }
}

fn spawn_dialogue_runner(mut commands: Commands, project: Res<YarnProject>) {
    info!("Starting dialogue runner.");
    // Create a dialogue runner from the project.
    let dialogue_runner = project.create_dialogue_runner();
    // ⚠️ TODO: Only run dialogues on interaction!
    //dialogue_runner.start_node("Start");
    commands.spawn(dialogue_runner);
}