/// <summary>
/// Used when a page is leaved to detach webview elements
/// </summary>
/// <param name="e">Argument of the navigation event</param>
protected override void OnNavigatedFrom(NavigationEventArgs e)
{
RunOnUI(() =>
{
/* Remove notification from grid */
if (mCapptainGrid.Children.Contains(mNotification))
{
mNotification.UnsetHandler();
mCapptainGrid.Children.Remove(mNotification);
}
/* Remove notification from grid */
if (mCapptainGrid.Children.Contains(mAnnouncement))
{
mAnnouncement.UnsetHandler();
mCapptainGrid.Children.Remove(mAnnouncement);
}
/* Forward navigation event */
base.OnNavigatedFrom(e);
});
}
/// <summary>
/// Initialize overlay on the current page
/// </summary>
public void InitOverlay()
{
/* We have to use RunOnUI to ensure to be in the same thread pool than UI */
#pragma warning disable 4014
RunOnUI(() =>
{
/* capptainGrid is locked to ensure fast switching between page doesn't crash the app */
lock (thisLock)
{
mCapptainGrid = new Grid();
/* Check if customer have tagged a grid with "capptainGrid" */
mCapptainGrid = FindChildControl <Grid>(Window.Current.Content, "CapptainGrid") as Grid;
/* Pick the first grid element founded */
if (mCapptainGrid == null)
{
mCapptainGrid = FindChildControl <Grid>(Window.Current.Content, "") as Grid;
}
/* Take the instance of capptain UI element to add them on capptain grid */
mNotification = CapptainOverlayNotification.Instance;
mAnnouncement = CapptainOverlayAnnoucement.Instance;
/* If we have a grid then insert the overlay in it */
if (mCapptainGrid != null)
{
/* Check that notification is not already set */
if (!mCapptainGrid.Children.Contains(mNotification))
{
/* Add it */
try
{
mCapptainGrid.Children.Add(mNotification);
}
catch (Exception)
{
/* Because of threading context we can grab an unexpected error due to webview insertion
* But we have to ensure overlay creation */
InitOverlay();
return;
}
/* Set the display_orientation_change event to resize the notification */
mNotification.SetHandler();
/* Made the first resize to be sure to match the current application size */
mNotification.SetWebView();
}
/* Check an announcement is already set */
if (!mCapptainGrid.Children.Contains(mAnnouncement))
{
/* Add it */
try
{
mCapptainGrid.Children.Add(mAnnouncement);
}
catch (Exception)
{
/* Because of threading context we can grab an unexpected error due to webview insertion
* But we have to ensure overlay creation */
InitOverlay();
return;
}
/* Set the display_orientation_change event to resize the notification */
mAnnouncement.SetHandler();
/* Made the first resize to be sure to match the current application size */
mAnnouncement.SetWebView();
}
}
else
{
/* Even if we have locked we ensure that event on overlay are detach */
mNotification.UnsetHandler();
mAnnouncement.UnsetHandler();
mCapptainGrid = new Grid();
/* Run again the init because sometime graphical context isn't set fine */
InitOverlay();
}
}
});
}
