MDH.Displays.Connector 1.0.2

MDH.Displays.Connector

.NET client for MDH Displays. Publish variables to displays and manage the assets they use.

Targets netstandard2.0, net48, net8.0-windows. The WPF status bar item and settings editor are on the two Windows targets only.

Install

dotnet add package MDH.Displays.Connector

Quick start

var settings = Settings.LoadFromFile(@"C:\ProgramData\YourApp\displays.xml");
if (!settings.IsConfigured)
{
    Log(settings.ConfigurationProblem);
    return;
}

var connection = new Connection(settings);
connection.OnError += Log;
connection.ConnectionStateChanged += c => UpdateUi(c.IsConnected);
connection.Connect();

connection.Publish(new HeatVariables(heat));

Variable groups

public sealed class HeatVariables : VariableGroup
{
    private readonly Heat _heat;
    public HeatVariables(Heat heat) => _heat = heat;

    public override string Id   => "heat";
    public override string Name => "Current heat";

    protected override void Build(VariableGroupBuilder b)
    {
        b.AddString("name", _heat.Name)
         .AddNumber("stand", _heat.Stand)
         .AddBoolean("running", _heat.IsRunning)
         .AddDateTime("startedAt", _heat.StartedAt);
    }
}

Builder methods: AddString, AddNumber (int or double), AddBoolean, AddDateTime, AddStruct(name, value, fields).

• Id must be stable across publishes; it identifies the group to the display.
• The whole group is rewritten each publish; Build must declare every variable every time.
• Build runs on the background loop at serialisation time, not when Publish returns. Snapshot mutable data first.
• Variable ids derive from {groupId}:{name}.

API

Connection(Settings settings);

void Connect();       // background, auto-reconnecting; no-op if disabled or running
void Disconnect();
void Publish(VariableGroup group);   // non-blocking

Task<string?>              UploadAssetAsync(string serverPath, byte[] data, bool overwrite = true);
Task<IReadOnlyList<Asset>> ListAssetsAsync();
Task<string?>              DeleteAssetAsync(string serverPath);

Settings Settings { get; }
bool IsEnabled { get; }
bool IsConnected { get; }

event Action<Connection>? ConnectionStateChanged;
event Action<string>?     OnError;

Publishes are coalesced per group — only the latest update is sent. All groups are re-flushed after a reconnect.

Settings

IsConfigured / ConfigurationProblem report whether the settings are usable. LoadFromFile returns defaults if the file is missing; throws if it exists and cannot be parsed.

Embed in a host's settings tree:

[Category("MDH Displays"), DisplayName("Connection")]
public Settings Displays { get; set; } = new Settings();

Serialises as one XML element (MdhDisplaysSettings) and expands in a PropertyGrid.

WPF status bar item

<StatusBar>
  <displays:DisplaysStatusBarItem x:Name="Item" FontWeight="Bold" />
</StatusBar>

Item.Settings = mySettings;
Item.ConnectRequested    += (s, e) => connection.Connect();
Item.DisconnectRequested += (s, e) => connection.Disconnect();

connection.ConnectionStateChanged += c =>
    Dispatcher.Invoke(() => Item.IsConnected = c.IsConnected);

Appearance: Label, FontWeight, FontSize, FontFamily, Padding, and one brush property per state (ConnectedBackground, DisconnectedForeground, …).

Add host-specific menu items to the right-click menu, in XAML or in code. They render between Connect/Disconnect and Properties.

<displays:DisplaysStatusBarItem>
  <displays:DisplaysStatusBarItem.HostMenuItems>
    <MenuItem Header="Upload Portraits" Click="OnClick" />
  </displays:DisplaysStatusBarItem.HostMenuItems>
</displays:DisplaysStatusBarItem>

Item.HostMenuItems.Add(new MenuItem { Header = "Upload Portraits" });

Threading

ConnectionStateChanged and OnError may fire on background threads. Marshal to the UI thread in your handlers.

Status

Not verified against a live server since the connector moved repositories.