public static void Init(SynchronizationContext uiContext, IPlatformOptions options)
{
ThreadHelper.Init(uiContext);
PlatformOptions = options;
}
/// <summary>
/// Will initialize anything needed within the framework.
/// </summary>
/// <param name="uiContext">Example: Pass through SynchronizationContext.Current</param>
public static void Init(SynchronizationContext uiContext)
{
ThreadHelper.Init(uiContext);
}
public StackResult Navigate(IStackOptions options)
{
lock (_lock)
{
StackResult stackResult = StackResult.StackStarted;
if (options.StackChoice == null)
{
throw new NullReferenceException($"{nameof(NavigationService)}.{nameof(Navigate)} can not accept a null {nameof(options.StackChoice)}");
}
// Don't change to the same stack
if (_currentStack != null &&
_currentStack.Equals(options.StackChoice))
{
return(StackResult.None);
}
if (!_stacks.ContainsKey(options.StackChoice))
{
throw new NullReferenceException($"{nameof(NavigationService)} does not contain a stack named {options.StackChoice.ToString()}");
}
// Current / Previous Stack
IStack oldStack = null;
if (_currentStack != null)
{
oldStack = _stacks[_currentStack];
oldStack.StateChange(StackStatus.Background); // Schedules NoHistoryRemoval
}
var stack = _stacks[options.StackChoice];
_currentStack = options.StackChoice;
// Set new status
stack.Proxy.ViewStatus = VisualStatus.Visible;
// Switch over services
_displayService.Init(stack.Proxy);
ThreadHelper.RunOnUIThread(async() =>
{
if (stack.Status == StackStatus.Stopped)
{
object args = null;
// If ArgsKey present only pass args along if the StartKey is the same
if ((!string.IsNullOrEmpty(options?.ArgsKey) && stack.NavigationStartKey == options?.ArgsKey) || string.IsNullOrEmpty(options?.ArgsKey))
{
stackResult = stackResult | StackResult.ArgsPassed;
args = options?.Args;
}
var loadStartKey = options?.PredefinedStack == null;
if (loadStartKey)
{
stackResult = stackResult | StackResult.NavigationStarted;
}
await stack.StartNavigation(args: args, loadStartKey: loadStartKey);
}
// Preload Stack
if (options?.PredefinedStack != null)
{
foreach (var page in options.PredefinedStack)
{
await Navigate(page.Key, page.Value);
}
}
// Find mainview from ViewHierarchy
var viewContainer = _viewContainers[_stackViewContainers[options.StackChoice]];
// Tabbed View
if (viewContainer is ITabbedContainer)
{
var tabbedView = viewContainer as ITabbedContainer;
// Must start all stacks on the first tabbed view load
// because when the tab changes, I can't block while I load an individual tab
// I can only block moving to an entire page
foreach (var item in tabbedView.Children)
{
if (item.Status == StackStatus.Stopped)
{
await item.StartNavigation(options?.Args);
}
}
}
// MasterDetail View load
if (viewContainer is IMasterDetailContainer)
{
var masterDetailContainer = viewContainer as IMasterDetailContainer;
if (masterDetailContainer.DetailStack != null)
{
// Setup Detail Stack
var detailStack = _stacks[masterDetailContainer.DetailStack.StackIdentifier];
if (detailStack.Status == StackStatus.Stopped)
{
await detailStack.StartNavigation(options?.Args);
}
masterDetailContainer.Proxy.DetailNativeView = detailStack.Proxy.NativeView;
// Setup Master Stack
var masterStack = _stacks[masterDetailContainer.MasterStack.StackIdentifier];
if (masterStack.Status == StackStatus.Stopped)
{
await masterStack.StartNavigation(options?.Args);
}
masterDetailContainer.Proxy.MasterNativeView = masterStack.Proxy.NativeView;
}
}
_currentViewContainer = viewContainer;
if (!string.IsNullOrEmpty(options.ViewKey))
{
await Navigate(options.ViewKey, options.Args, options.NewInstance);
}
_setRoot?.Invoke(viewContainer.NativeView);
if (oldStack != null)
{
await oldStack.StackChanged();
}
});
return(stackResult);
}
}
public Task <IView> Build(ITypeDefinition definition)
{
lock (_lock)
{
IView view = null;
if (definition.CacheView && _cachedViews.ContainsKey(definition.Type))
{
view = _cachedViews[definition.Type];
}
else
{
ConstructorInfo constructor = null;
object[] parameters = null;
constructor = definition.Type.GetTypeInfo()
.DeclaredConstructors
.FirstOrDefault(c => !c.GetParameters().Any());
parameters = new object[] { };
if (constructor == null)
{
throw new InvalidOperationException(
$"No suitable constructor found for view {definition.Type.ToString()}");
}
ThreadHelper.RunOnUIThread(() =>
{
view = constructor.Invoke(parameters) as IView;
});
if (view == null)
{
throw new InvalidOperationException(
$"View {definition.Type.ToString()} does not implement the interface {nameof(IView)}");
}
// Assign Binding Context
if (_viewsByType.ContainsKey(definition.Type))
{
view.BindingContext = GetBindingContext(definition.Type);
var multiView = view as IMultiView;
if (multiView != null)
{
foreach (var p in multiView.Views)
{
p.BindingContext = GetBindingContext(p.GetType());
}
}
}
else
{
throw new InvalidOperationException(
"No suitable view model found for view " + definition.Type.ToString());
}
if (definition.CacheView)
{
_cachedViews.Add(definition.Type, view);
}
}
return(Task.FromResult(view));
}
}
public async Task Navigate(string key, object args, bool newInstance, bool popSource)
{
using (var releaser = await _lock.LockAsync())
{
await ThreadHelper.RunOnUIThreadAsync(async() =>
{
// Do not navigate to the same view, unless duplicate
if (key == CurrentView.Key && !newInstance)
{
var model = CurrentViewTrack[CurrentViewTrack.Count - 1].BindingContext as IViewModel;
if (model != null)
{
model.OnNavigated(args).ConfigureAwait(false).GetAwaiter(); // Do not await.
}
return;
}
var platformKey = Abstraction.Tuple.Create(key, App.PlatformOptions.Platform);
var genericKey = Abstraction.Tuple.Create(key, (string)null);
Abstraction.Tuple <string, string> tupleKey = Abstraction.Tuple.Create(string.Empty, (string)null);
TypeDefinition viewKey = null;
if (_viewsByKey.ContainsKey(platformKey))
{
tupleKey = platformKey;
viewKey = _viewsByKey[platformKey];
}
else if (_viewsByKey.ContainsKey(genericKey))
{
tupleKey = genericKey;
viewKey = _viewsByKey[genericKey];
}
if (viewKey != null)
{
var typeDefinition = viewKey;
if (Proxy == null)
{
throw new Exception($"{nameof(INavigationProxy)} is null. Did you forget to call NavigationService.Init()?");
}
if (_viewKeyTracking.Contains(tupleKey) && !newInstance)
{
// Silent pop those in the middle, then do a pop, so its a single back animation according to the user
var index = 0;
foreach (var item in _viewKeyTracking)
{
if (item.Key != key)
{
index += 1;
}
else
{
break;
}
}
var count = _viewKeyTracking.Count;
for (int i = count - 2; i > index; i--)
{
await Proxy.SilentPopAsync(1);
_viewKeyTracking.RemoveAt(i);
}
// Now should be single pop to go back to the page.
while (key != CurrentView.Key)
{
if (args == null)
{
await Proxy.PopAsync();
}
else
{
await Proxy.PopAsync(args);
}
}
}
else
{
var view = await _viewService.Build(typeDefinition) as IView;
if (view == null)
{
throw new Exception(String.Format("Unable to build view {0}", typeDefinition.Type.ToString()));
}
Proxy.SetNavigationBar(ShowNavigationBar, view);
var model = view.BindingContext as IViewModel;
if (model != null)
{
var arg = new Args();
await model.OnPreNavigate(args, arg);
// If user cancelled, stop forward navigation
if (arg.Cancel)
{
return;
}
view.Appearing += (s, e) => { model.OnAppearing(); };
view.Disappearing += (s, e) => { model.OnDisappearing(); };
view.OnBackButtonPressed = () => { return(model.OnBackButtonPressed()); };
}
var popCurrent = false;
if (Proxy != null && !string.IsNullOrEmpty(CurrentView.Key))
{
if (_viewsByKey[CurrentView].NoHistory)
{
popCurrent = true;
}
}
await Proxy.PushAsync(view);
if (popCurrent || popSource) // Pop the one behind without showing it
{
await Proxy.SilentPopAsync(1);
// Remove the top one as the new tracking key hasn't been added yet
_viewKeyTracking.RemoveAt(_viewKeyTracking.Count - 1);
}
_viewKeyTracking.Add(tupleKey);
CurrentView = tupleKey;
CurrentViewTrack.Add(view);
if (model != null)
{
model.OnNavigated(args).ConfigureAwait(false).GetAwaiter(); // Do not await.
}
}
}
else
{
throw new ArgumentException(
$"No such key: {key}. Did you forget to call NavigationService.Map?",
nameof(key));
}
});
}
}
public static void Init()
{
ThreadHelper.Init(SynchronizationContext.Current);
}
