Screen contracts

Lobby, Character, Alliance, Campaign and Shop each have a screen contract: a small interface the page observes and calls. Use it rather than the screen's presenter. The page renders a view and sends commands; loading, retries and double taps are handled for you.

Screen	Namespace (SilverTiger.ProjectV.Unity.Presentation.*)	View	Commands
IProjectVLobbyScreen	.Lobby	ProjectVLobbyView	none
IProjectVShopScreen	.Shop	ProjectVShopView	PurchaseAsync(offerId, quantity)
IProjectVCampaignScreen	.Campaign	ProjectVCampaignView	BeginMissionAsync(missionId), CancelSceneLoadAsync()
IProjectVCharacterScreen	.Character	ProjectVCharacterView	SelectCharacterAsync, LevelUpAsync, UpgradeSkillAsync, UpgradeCastSkillAsync, ResetSkillsAsync, ResetLevelAsync
IProjectVAllianceScreen	.Alliance	ProjectVAllianceView	SelectAllyAsync, LevelUpAsync, UpgradeWeaponSkillAsync, ResetLevelAsync

Startup, Authentication, Account, Header and Gameplay data have no screen contract; use their presenters. On Character, equipment, backpack, skins and confirmation dialogs are not on the contract yet; use IProjectVCharacterPresenter for those.

The shape

XxxView Current { get; }                         // the last confirmed data, never null
IDisposable Observe(Action<XxxView> render);     // render now, then again when the data changes
Task<ProjectVResult> SomeCommandAsync(...);      // one request per tap

• Observe renders at once, then only when the data changes. It never calls you while a request is in flight, and render always runs on the Unity main thread. It also loads the data if needed, so do not call a refresh. Dispose the result when the page closes.
• A view always shows the last confirmed data. IsLoading is true only until the first data arrives; LoadError explains a failed first load, for a retry prompt. Previews (EXP, level reset) also use the confirmed data, so they do not drop to zero during a request.
• Commands return ProjectVResult. IsSuccess tells you whether the server confirmed the action. Message is text for the player, empty on success; show it as it is. The new data arrives through Observe, not through the result.
• A repeated tap joins the running command and gets the same result. You do not need to disable the button or debounce it.
• Commands take no CancellationToken. Closing the page does not undo the action on the server. Check that the page still exists before using the result.
• No Sync or Refresh button is needed on Character and Alliance. If a result could not be confirmed, those screens resynchronise and redraw by themselves. On Shop, show the message and let the player decide whether to try again.

Example: Shop

From ProjectV-Client's ShopUIManager:

private IProjectVShopScreen shop = null!;
private IDisposable? subscription;

[Inject]
public void Construct(IProjectVShopScreen shop)
{
    this.shop = shop ?? throw new ArgumentNullException(nameof(shop));
}

private void Start()
{
    // Renders the current catalog now, then again only when the offers change.
    subscription = shop.Observe(ApplyShopView);
}

private void OnDestroy()
{
    subscription?.Dispose();
    subscription = null;
}

private void ApplyShopView(ProjectVShopView view)
{
    if (this == null)
    {
        return;
    }
    if (view.IsLoading)
    {
        ShowLoading(view.LoadError);
        return;
    }
    RenderOffers(view.Offers);
}

private async Task BuyAsync(string offerId, int quantity)
{
    // The listing and balances update through ApplyShopView once the server confirms.
    var result = await shop.PurchaseAsync(offerId, quantity);
    if (this != null && !result.IsSuccess)
    {
        ShowMessage(result.Message);
    }
}

private void ShowLoading(string? loadError) { }
private void RenderOffers(IReadOnlyList<ProjectVShopOfferView> offers) { }
private void ShowMessage(string message) { }

Example: begin a mission

Based on ProjectV-Client's UICampaignManager, with a guard against taps on other missions:

private async Task BeginAndLoadAsync(ProjectVCampaignMission mission, string sceneName, CancellationToken token)
{
    // Set the guard before awaiting: a tap on another mission while one starts
    // gets the first mission's result, so ignore taps until this one is done.
    if (starting)
    {
        return;
    }
    starting = true;

    var result = await campaign.BeginMissionAsync(mission.MissionId.Value);
    if (!result.IsSuccess)
    {
        starting = false;
        ShowMessage(result.Message);
        return;
    }

    if (token.IsCancellationRequested || this == null)
    {
        return;
    }

    if (string.IsNullOrEmpty(sceneName))
    {
        await campaign.CancelSceneLoadAsync();
        starting = false;
        return;
    }

    // starting stays true: the scene loads once for this run.
    SceneLoader.Instance.LoadScene(sceneName);   // game-owned loader
}

Hosts without VContainer, and tests

ProjectVPresentationLifetimeScope registers one instance of each screen for the session; inject the interface. Tools and tests can build a screen over a presenter with ProjectVScreens.Lobby(presenter), .Shop, .Campaign, .Character or .Alliance. The optional dispatch argument moves rendering to the main thread; without it, render runs inline. ProjectVScreens.CharacterView(snapshot) builds a Character view from one snapshot, without a presenter.

Next: Presenter reference.