internal ShellState(ShellBase shell)
{
Shell = shell;
Shell.Closing += ShellOnClosing;
Shell.Closed += ShellOnClosed;
}
/// <summary>
/// Notifies <see cref="Data"/> and <see cref="View"/> about navigation completion.
/// </summary>
/// <param name="parent"></param>
internal void NavigationCompleted(ShellBase parent)
{
(Data as INavigatable)?.Navigated();
if (View != null)
{
Shell.Dispatcher.Invoke(() => View.Navigated(Shell, parent));
}
}
private static Task NavigateInner <T>(T target) where T : INavigationTarget
{
return(InvokeOnDispatcherAsync(() =>
{
if (_shellResolver == null)
{
throw new InvalidOperationException("Shell resolver must be set before invoking Navigate method.");
}
var type = target.GetType();
if (!_navitaionTargetToConfigs.ContainsKey(type))
{
NavigationFailed?.Invoke(NavigationFailReason.NotConfigured, target);
return;
}
//1. Find config
var configs = _navitaionTargetToConfigs[type];
// If registered more than 1 config, find config which matches target. If no found or only 1 config - use first navigation config.
var config = (configs.Count > 1 ? configs.FirstOrDefault(x => x.MatchesTarget(target)) : null) ?? configs.First();
var navMode = config.Mode;
if (navMode == NavigationMode.DependsOnTarget)
{
navMode = config.GetNavigationMode(target);
}
// Navigation mode after getting from config cannot be NavigationMode.DependsOnTarget
if (navMode == NavigationMode.DependsOnTarget)
{
throw new InvalidOperationException("NavigationConfig.GetNavigationMode returned invalid value: NavigationMode.DependsOnTarget");
}
ShellState shellState = null;
bool existingShell = false;
if (!config.AllowMultiple)
{
var conflict = _states.FirstOrDefault(x => x.Config == config);
if (conflict != null)
{
//Check if config can handle navigation when already navigated.
try
{
if (config.TryHandleNavigation(target, conflict.Data))
{
return;
}
}
catch (NotImplementedException) { }
NavigationFailed?.Invoke(NavigationFailReason.NotAllowedToHaveMultiple, target);
return; // No futher navigation required.
}
}
//Only for default navigation mode can be searched existing shells.
if (navMode == NavigationMode.Default)
{
//Try find available shell
foreach (var state in _states)
{
// Check if config allows reuse shell
if (!state.Config.CanLeave(target))
{
continue;
}
//Only Default and NewWindow can be reused.
if (!(state.Mode == NavigationMode.Default || state.Mode == NavigationMode.NewWindow))
{
continue;
}
// On this line shell can be reused.
shellState = state;
existingShell = true;
break;
}
}
// Create shell data from config
object shellData;
ShellBase parent = null;
if (!existingShell)
{
// Check if need to set parent.
if ((navMode == NavigationMode.ChildWindow ||
navMode == NavigationMode.DialogWindow))
{
// Set parent window if shellState.Mode is Dialog or Child
if (_states.Any()) //TODO: Improve logic for selecting parent window.
{
parent = _states[0].Shell;
}
}
// Create new shell if not found available.
var shell = _shellResolver.CreateShell(parent);
shellState = new ShellState(shell);
shellState.ShellClosed += ShellStateOnShellClosed;
_states.Add(shellState);
shellData = config.GenerateDataForTarget(target, shellState.Shell.Dispatcher);
if (shellData == null)
{
throw new InvalidOperationException("Config returned null from generating object for target.");
}
// Set data in ShellBase
shellState.Load(navMode, config, target, shellData);
// Show shell.
if (shellState.Mode == NavigationMode.DialogWindow)
{
shellState.Shell.Dispatcher.InvokeAsync(() => shellState.Shell.ShowDialog());
}
else
{
shellState.Shell.Dispatcher.Invoke(() =>
{
shellState.Shell.Show();
shellState.Shell.Activate();
});
}
}
else
{
shellData = config.GenerateDataForTarget(target, shellState.Shell.Dispatcher);
if (shellData == null)
{
throw new InvalidOperationException("Config returned null from generating object for target.");
}
// Unload current navigatable data.
shellState.Unload();
// Set data in ShellBase
shellState.Load(navMode, config, target, shellData);
}
//Navigation to target comleted.
shellState.NavigationCompleted(parent);
}));
}
