static bool ShouldIntercept(Control control, global::Windows.UI.Xaml.VisualState state, string stateName)
{
if (state == null || state.Name == "Normal")
{
// We don't intercept the "Normal" state, that's the base state onto which Forms applies properties
return(false);
}
// Retrieve the VisualElement we're managing states for
var visualElement = GetFormsElement(control);
if (visualElement == null)
{
return(false);
}
// Retrieve the set of VisualStateGroups for the VisualElement
var groups = VisualStateManager.GetVisualStateGroups(visualElement);
if (groups == null)
{
// No groups?
// Then the user disabled legacy color management through the platform specific, not by using the XFVSM
// So our ignored states lists is effectively "Disabled" and "Focused"
if (state.Name == "Disabled" || state.Name == "Focused")
{
return(true);
}
}
else
{
// Check the states the XFVSM is managing
foreach (VisualStateGroup vsg in groups)
{
foreach (VisualState vs in vsg.States)
{
if (vs.Name == stateName)
{
// The XFVSM is already handling this state, so don't let the Windows VSM do it
return(true);
}
}
}
}
return(false);
}
// For most of the UWP controls, this custom VisualStateManager is injected to prevent the default Windows
// VSM from handling states which the Forms VSM is already managing.
// The exception are the controls which are built on TextBox (SearchBar, Entry, Editor); there's a UWP
// bug wherein the GoToStateCore override for those controls is never called (Item 10976357 in VSTS)
// So until that's resolved, the FormsTextBox control is doing that work as best it can.
protected override bool GoToStateCore(Control control, FrameworkElement templateRoot, string stateName,
global::Windows.UI.Xaml.VisualStateGroup @group, global::Windows.UI.Xaml.VisualState state, bool useTransitions)
{
// If this custom VSM is in play, it's because the control is using the Forms VSM or the user has disabled
// legacy color handling. Either way, we may need to prevent the Windows VSM from transitioning to the new
// state. So we intercept the transition here.
if (ShouldIntercept(control, state, stateName))
{
return(false);
}
return(base.GoToStateCore(control, templateRoot, stateName, @group, state, useTransitions));
}
void UpdateOnColor()
{
if (!(Cell is SwitchCell switchCell))
{
return;
}
var color = switchCell.OnColor == Color.Default
? _defaultOnColor
: new SolidColorBrush(switchCell.OnColor.ToWindowsColor());
var nativeSwitch = FrameworkElementExtensions.GetFirstDescendant <ToggleSwitch>(this);
// change fill color in switch rectangle
var rects = nativeSwitch.GetDescendantsByName <global::Windows.UI.Xaml.Shapes.Rectangle>("SwitchKnobBounds");
foreach (var rect in rects)
{
rect.Fill = color;
}
// change color in animation on PointerOver
var grid = nativeSwitch.GetFirstDescendant <global::Windows.UI.Xaml.Controls.Grid>();
var gridVisualStateGroups = global::Windows.UI.Xaml.VisualStateManager.GetVisualStateGroups(grid);
global::Windows.UI.Xaml.VisualStateGroup vsGroup = null;
foreach (var visualGroup in gridVisualStateGroups)
{
if (visualGroup.Name == "CommonStates")
{
vsGroup = visualGroup;
break;
}
}
if (vsGroup == null)
{
return;
}
global::Windows.UI.Xaml.VisualState vState = null;
foreach (var visualState in vsGroup.States)
{
if (visualState.Name == "PointerOver")
{
vState = visualState;
break;
}
}
if (vState == null)
{
return;
}
var visualStates = vState.Storyboard.Children;
foreach (ObjectAnimationUsingKeyFrames item in visualStates)
{
if ((string)item.GetValue(Storyboard.TargetNameProperty) == "SwitchKnobBounds")
{
item.KeyFrames[0].Value = color;
break;
}
}
}