public ShellToolbarTracker(IShellContext shellContext, AToolbar toolbar, DrawerLayout drawerLayout)
{
ShellContext = shellContext ?? throw new ArgumentNullException(nameof(shellContext));
_toolbar = toolbar ?? throw new ArgumentNullException(nameof(toolbar));
_drawerLayout = drawerLayout ?? throw new ArgumentNullException(nameof(drawerLayout));
_appBar = _toolbar.Parent.GetParentOfType <AppBarLayout>();
_globalLayoutListener = new GenericGlobalLayoutListener(() => UpdateNavBarHasShadow(Page));
_appBar.ViewTreeObserver.AddOnGlobalLayoutListener(_globalLayoutListener);
_toolbar.SetNavigationOnClickListener(this);
((IShellController)ShellContext.Shell).AddFlyoutBehaviorObserver(this);
ShellContext.Shell.Toolbar.PropertyChanged += OnToolbarPropertyChanged;
}
public object WatchForChangesOnLayout(VisualElement visualElement, Action action)
{
if (action == null)
{
return(null);
}
var view = Platform.Android.Platform.GetRenderer(visualElement);
var androidView = view?.View;
if (androidView == null || !androidView.IsAlive())
{
return(null);
}
ViewTreeObserver.IOnGlobalLayoutListener listener = null;
listener = new GenericGlobalLayoutListener(() =>
{
if (!androidView.IsAlive())
{
action = null;
androidView = null;
try
{
_mainActivity?.Window?.DecorView?.RootView?.ViewTreeObserver?.RemoveOnGlobalLayoutListener(listener);
}
catch
{
// just in case something along the call path here is disposed of
}
return;
}
action?.Invoke();
});
androidView.ViewTreeObserver.AddOnGlobalLayoutListener(listener);
return(listener);
}
protected virtual void LoadView(IShellContext shellContext)
{
var context = shellContext.AndroidContext;
var layoutInflator = shellContext.Shell.FindMauiContext().GetLayoutInflater();
var coordinator = (ViewGroup)layoutInflator.Inflate(Controls.Resource.Layout.flyoutcontent, null);
_appBar = coordinator.FindViewById <AppBarLayout>(Controls.Resource.Id.flyoutcontent_appbar);
(_appBar.LayoutParameters as CoordinatorLayout.LayoutParams)
.Behavior = new AppBarLayout.Behavior();
_rootView = coordinator as ViewGroup;
_appBar.AddOnOffsetChangedListener(this);
_actionBarHeight = context.GetActionBarHeight();
UpdateFlyoutHeader();
var metrics = context.Resources.DisplayMetrics;
var width = Math.Min(metrics.WidthPixels, metrics.HeightPixels);
width -= _actionBarHeight;
coordinator.LayoutParameters = new LP(width, LP.MatchParent);
_bgImage = new ImageView(context)
{
LayoutParameters = new LP(coordinator.LayoutParameters)
};
UpdateFlyoutHeaderBehavior();
_shellContext.Shell.PropertyChanged += OnShellPropertyChanged;
UpdateFlyoutBackground();
UpdateVerticalScrollMode();
UpdateFlyoutFooter();
if (FlyoutView.FlyoutBehavior == FlyoutBehavior.Locked)
{
OnFlyoutViewLayoutChanging();
}
if (View is ShellFlyoutLayout sfl)
{
// The purpose of this code is to load the flyout content after
// the details content is visible.
// Loading the Recycler View the first time is expensive
// so we want to delay loading to the latest possible point in time so
// it doesn't delay initial startup.
GenericGlobalLayoutListener ggll = null;
ggll = new GenericGlobalLayoutListener(InitialLoad);
sfl.ViewTreeObserver.AddOnGlobalLayoutListener(ggll);
void InitialLoad()
{
OnFlyoutViewLayoutChanging();
if (_flyoutContentView == null || ggll == null)
{
return;
}
var listener = ggll;
ggll = null;
// Once initial load has finished let's just attach to Layout Changing
sfl.ViewTreeObserver.RemoveOnGlobalLayoutListener(listener);
sfl.LayoutChanging += OnFlyoutViewLayoutChanging;
}
}
}
