public WindowConductor(Window window, object viewModel)
{
this.window = window;
this.viewModel = viewModel;
// They won't be able to request a close unless they implement IChild anyway...
var viewModelAsChild = this.viewModel as IChild;
if (viewModelAsChild != null)
{
viewModelAsChild.Parent = this;
}
ScreenExtensions.TryActivate(this.viewModel);
var viewModelAsScreenState = this.viewModel as IScreenState;
if (viewModelAsScreenState != null)
{
window.StateChanged += this.WindowStateChanged;
window.Closed += this.WindowClosed;
}
if (this.viewModel is IGuardClose)
{
window.Closing += this.WindowClosing;
}
}
/// <summary>
/// Close was requested by the child
/// </summary>
/// <param name="item">Item to close</param>
/// <param name="dialogResult">DialogResult to close with, if it's a dialog</param>
async void IChildDelegate.CloseItem(object item, bool?dialogResult)
{
if (item != this.viewModel)
{
logger.Warn("IChildDelegate.CloseItem called with item {0} which is _not_ our ViewModel {1}", item, this.viewModel);
return;
}
var guardClose = this.viewModel as IGuardClose;
if (guardClose != null && !await guardClose.CanCloseAsync())
{
logger.Info("Close of ViewModel {0} cancelled because CanCloseAsync returned false", this.viewModel);
return;
}
logger.Info("ViewModel {0} close requested with DialogResult {1} because it called RequestClose", this.viewModel, dialogResult);
this.window.StateChanged -= this.WindowStateChanged;
this.window.Closed -= this.WindowClosed;
this.window.Closing -= this.WindowClosing;
// Need to call this after unregistering the event handlers, as it causes the window
// to be closed
if (dialogResult != null)
{
this.window.DialogResult = dialogResult;
}
ScreenExtensions.TryClose(this.viewModel);
this.window.Close();
}
/// <summary>
/// Switch the active item to the given item
/// </summary>
/// <param name="newItem">New item to activate</param>
/// <param name="closePrevious">Whether the previously-active item should be closed</param>
protected virtual void ChangeActiveItem(T newItem, bool closePrevious)
{
ScreenExtensions.TryDeactivate(this.ActiveItem);
if (closePrevious)
{
this.CloseAndCleanUp(this.ActiveItem, this.DisposeChildren);
}
this._activeItem = newItem;
if (newItem != null)
{
this.EnsureItem(newItem);
if (this.IsActive)
{
ScreenExtensions.TryActivate(newItem);
}
else
{
ScreenExtensions.TryDeactivate(newItem);
}
}
this.NotifyOfPropertyChange("ActiveItem");
}
/// <summary>
/// Deactive the given item
/// </summary>
/// <param name="item">Item to deactivate</param>
public override void DeactivateItem(T item)
{
if (item != null && item.Equals(this.ActiveItem))
{
ScreenExtensions.TryDeactivate(this.ActiveItem);
}
}
/// <summary>
/// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
/// </summary>
public override void Dispose()
{
// Don't create the root ViewModel if it doesn't already exist...
ScreenExtensions.TryDispose(this._rootViewModel);
// Dispose the container last
base.Dispose();
}
private void WindowClosed(object sender, EventArgs e)
{
// Logging was done in the Closing handler
this.window.StateChanged -= this.WindowStateChanged;
this.window.Closed -= this.WindowClosed;
this.window.Closing -= this.WindowClosing; // Not sure this is required
ScreenExtensions.TryClose(this.viewModel);
}
/// <summary>
/// Activate the given item and set it as the ActiveItem, deactivating the previous ActiveItem
/// </summary>
/// <param name="item">Item to deactivate</param>
public override void ActivateItem(T item)
{
if (item != null && item.Equals(this.ActiveItem))
{
if (this.IsActive)
{
ScreenExtensions.TryActivate(this.ActiveItem);
}
}
else
{
this.ChangeActiveItem(item, false);
}
}
private void WindowStateChanged(object sender, EventArgs e)
{
switch (this.window.WindowState)
{
case WindowState.Maximized:
case WindowState.Normal:
logger.Info("Window {0} maximized/restored: activating", this.window);
ScreenExtensions.TryActivate(this.viewModel);
break;
case WindowState.Minimized:
logger.Info("Window {0} minimized: deactivating", this.window);
ScreenExtensions.TryDeactivate(this.viewModel);
break;
}
}
/// <summary>
/// Activate the given item, discarding the previous ActiveItem
/// </summary>
/// <param name="item">Item to active</param>
public override async void ActivateItem(T item)
{
if (item != null && item.Equals(this.ActiveItem))
{
if (this.IsActive)
{
ScreenExtensions.TryActivate(item);
}
}
else if (await this.CanCloseItem(this.ActiveItem))
{
// CanCloseItem is null-safe
this.ChangeActiveItem(item, true);
}
}
/// <summary>
/// Close an item, and clear its parent if it's set to the current parent
/// </summary>
/// <typeparam name="T">Type of conductor</typeparam>
/// <param name="parent">Parent</param>
/// <param name="item">Item to close and clean up</param>
/// <param name="dispose">True to dispose children as well as close them</param>
public static void CloseAndCleanUp <T>(this IConductor <T> parent, T item, bool dispose)
{
ScreenExtensions.TryClose(item);
var itemAsChild = item as IChild;
if (itemAsChild != null && itemAsChild.Parent == parent)
{
itemAsChild.Parent = null;
}
if (dispose)
{
ScreenExtensions.TryDispose(item);
}
}
/// <summary>
/// Deactive the given item, and choose another item to set as the ActiveItem
/// </summary>
/// <param name="item">Item to deactivate</param>
public override void DeactivateItem(T item)
{
if (item == null)
{
return;
}
if (item.Equals(this.ActiveItem))
{
var nextItem = this.DetermineNextItemToActivate(item);
this.ChangeActiveItem(nextItem, false);
}
else
{
ScreenExtensions.TryDeactivate(item);
}
}
/// <summary>
/// Activate the given item, and add it to the Items collection
/// </summary>
/// <param name="item">Item to activate</param>
public override void ActivateItem(T item)
{
if (item == null)
{
return;
}
this.EnsureItem(item);
if (this.IsActive)
{
ScreenExtensions.TryActivate(item);
}
else
{
ScreenExtensions.TryDeactivate(item);
}
}
/// <summary>
/// For each item in a list, set the parent to the current conductor
/// </summary>
/// <typeparam name="T">Type of conductor</typeparam>
/// <param name="parent">Parent to set the items' parent to</param>
/// <param name="items">Items to manipulate</param>
/// <param name="active">True to active the item, false to deactive it</param>
public static void SetParentAndSetActive <T>(this IConductor <T> parent, IEnumerable items, bool active)
{
foreach (var item in items)
{
var itemAsChild = item as IChild;
if (itemAsChild != null)
{
itemAsChild.Parent = parent;
}
if (active)
{
ScreenExtensions.TryActivate(item);
}
else
{
ScreenExtensions.TryDeactivate(item);
}
}
}
/// <summary>
/// When we're deactivated, also deactivate the ActiveItem
/// </summary>
protected override void OnDeactivate()
{
ScreenExtensions.TryDeactivate(this.ActiveItem);
}
/// <summary>
/// Deactive the given item
/// </summary>
/// <param name="item">Item to deactivate</param>
public override void DeactivateItem(T item)
{
ScreenExtensions.TryDeactivate(item);
}