/// <summary>
/// Initializes a new instance of the <see cref="HeaderViewModel"/> class.
/// </summary>
/// <param name="powerService">The power service implementation.</param>
/// <param name="titleService">The title service.</param>
/// <param name="policyProvider">The policy provider to execute ordinary commands.</param>
/// <param name="navigationManager">The navigation manager to navigate to a different page.</param>
public HeaderViewModel(
IPowerService powerService,
ITitleService titleService,
ICommandPolicyProvider policyProvider,
NavigationManager navigationManager)
{
if (powerService is null)
{
throw new ArgumentNullException(nameof(powerService));
}
if (titleService is null)
{
throw new ArgumentNullException(nameof(titleService));
}
if (policyProvider is null)
{
throw new ArgumentNullException(nameof(policyProvider));
}
if (navigationManager is null)
{
throw new ArgumentNullException(nameof(navigationManager));
}
this.WhenActivated(disposable =>
{
this.poweredOn = powerService.PoweredOn.ToProperty(this, x => x.PoweredOn).DisposeWith(disposable);
this.title = titleService.Title.ToProperty(this, x => x.Title).DisposeWith(disposable);
var policy = policyProvider.GetPolicy();
this.TogglePower = ReactiveCommand.CreateFromTask(async(ct) =>
{
switch (this.PoweredOn)
{
case true:
await policy.ExecuteAsync(
async(token) => await powerService.PowerOff(token),
ct);
break;
case false:
await policy.ExecuteAsync(
async(token) => await powerService.PowerOn(token),
ct);
break;
}
}).DisposeWith(disposable);
this.Settings = ReactiveCommand.Create(() =>
{
navigationManager.NavigateTo("/Settings");
}).DisposeWith(disposable);
this.canExecuteTogglePower = this.TogglePower.CanExecute.ToProperty(this, x => x.CanExecuteTogglePower).DisposeWith(disposable);
});
}