protected override void PrepareContainerForItemOverride(DependencyObject element, object item)
{
base.PrepareContainerForItemOverride(element, item);
WizardItem wizardItem = (WizardItem)element;
TranslateTransform transform = (TranslateTransform)wizardItem.RenderTransform;
if (!_isInDesignTool)
{
// Don't set visibility to collapsed yet. This gives all items time to render, reducing the chance of lost animations.
if (Items.IndexOf(wizardItem) != _selectedIndex)
{
transform.X = _offscreenPosition;
}
}
}
protected void UpdateDesignModeDisplay()
{
if (!_isInDesignTool)
{
return;
}
// Get the background panel
Panel backgroundPanel = GetTemplateChild("BackgroundPanel") as Panel;
if (backgroundPanel == null)
{
return;
}
// Remove any previous Border elements
backgroundPanel.Children.Clear();
// Item border properties
Thickness borderBorderThickness = new Thickness(1);
Thickness borderMargin = new Thickness(-1);
Brush borderBorderBrush = new SolidColorBrush(Colors.DarkGray);
Brush borderBackgroundBrush = (Brush)Application.Current.Resources["PhoneBackgroundBrush"];
// Arrange the wizard items and add display borders
for (int i = 0; i < Items.Count; i++)
{
WizardItem wizardItem = (WizardItem)Items[i];
// Current position, adjusted for the SelectedIndex
int position = i - SelectedIndex;
// Get the item's TranslateTransform
var transform = wizardItem.RenderTransform as TranslateTransform;
if (transform == null)
{
continue;
}
// Determine and set the x offset
double offset = position * (this.ActualWidth + 36);
if (position > 0)
{
offset += Margin.Right;
}
else if (position < 0)
{
offset -= Margin.Left;
}
transform.X = offset;
// Add a border if this isn't the currently selected item
if (position != 0)
{
Border border = new Border();
border.BorderThickness = borderBorderThickness;
border.Margin = borderMargin;
border.BorderBrush = borderBorderBrush;
border.Background = borderBackgroundBrush;
border.RenderTransform = transform;
// Add an inner border to display this control's background
Border innerBorder = new Border();
innerBorder.SetBinding(Border.BackgroundProperty, new Binding("Background")
{
Source = this
});
border.Child = innerBorder;
// Add the border to the background panel
backgroundPanel.Children.Add(border);
}
}
}
private void SetSelectedIndex(int oldValue, int value, bool useTransitions = true)
{
if (oldValue == value)
{
return;
}
int oldIndex = oldValue;
_selectedIndex = value;
if (!_loaded)
{
return;
}
if (oldIndex < 0 || value < 0)
{
useTransitions = false;
}
if (oldIndex >= Items.Count || value >= Items.Count)
{
useTransitions = false;
}
// If we're in design mode, just update the item positions and return
if (_isInDesignTool)
{
UpdateDesignModeDisplay();
return;
}
// If we aren't using transitions, cancel any previous animations and update the display
if (!useTransitions)
{
if (_currentStoryboard != null)
{
_currentStoryboard.Stop();
_currentStoryboard = null;
}
for (int i = 0; i < Items.Count; i++)
{
WizardItem item = (WizardItem)Items[i];
if (i == _selectedIndex)
{
item.Visibility = System.Windows.Visibility.Visible;
item.IsVisible = true;
((TranslateTransform)item.RenderTransform).X = 0;
}
else
{
item.Visibility = System.Windows.Visibility.Collapsed;
item.IsVisible = false;
}
}
return;
}
// Prepare the new item (off screen)
// Doing this early prevents lag/jumpiness in the middle of the animation.
WizardItem newItem = (WizardItem)Items[_selectedIndex];
((TranslateTransform)newItem.RenderTransform).X = ActualWidth;
newItem.Visibility = System.Windows.Visibility.Visible;
newItem.IsVisible = true;
// If we're already animating, don't do anything since the new index will be handled automatically
if (_currentStoryboard != null)
{
return;
}
// Set up transitions
double sourceX, destX;
if (oldIndex < SelectedIndex)
{
sourceX = ActualWidth;
destX = -ActualWidth;
}
else
{
sourceX = -ActualWidth;
destX = ActualWidth;
}
// Divide the animation time by two since it will be used twice (once for the outgoing item, and again for the incoming item)
TimeSpan halfAnimationTime = new TimeSpan(AnimationDuration.Ticks / 2);
Duration duration = new Duration(halfAnimationTime);
if (_currentStoryboard != null)
{
_currentStoryboard.Stop();
}
_currentStoryboard = new Storyboard();
_currentStoryboard.Duration = duration;
// Outgoing item animation
WizardItem oldItem = (WizardItem)Items[oldIndex];
DoubleAnimation itemAnimation = new DoubleAnimation();
itemAnimation.Duration = duration;
itemAnimation.EasingFunction = _animationEasingFunction;
itemAnimation.To = destX;
Storyboard.SetTarget(itemAnimation, oldItem.RenderTransform);
Storyboard.SetTargetProperty(itemAnimation, new PropertyPath(TranslateTransform.XProperty));
_currentStoryboard.Children.Add(itemAnimation);
_currentStoryboard.Completed += (s1, e1) =>
{
oldItem.Visibility = System.Windows.Visibility.Collapsed;
oldItem.IsVisible = false;
_currentStoryboard.Stop();
// Get the new item
int newIndex = _selectedIndex;
newItem = (WizardItem)Items[newIndex];
// Set up the new item (off screen)
((TranslateTransform)newItem.RenderTransform).X = sourceX;
newItem.Visibility = System.Windows.Visibility.Visible;
// Create a new storyboard
_currentStoryboard = new Storyboard();
_currentStoryboard.Duration = duration;
// Incoming item animation
itemAnimation = new DoubleAnimation();
itemAnimation.Duration = duration;
itemAnimation.EasingFunction = _animationEasingFunction;
itemAnimation.To = 0;
Storyboard.SetTarget(itemAnimation, newItem.RenderTransform);
Storyboard.SetTargetProperty(itemAnimation, new PropertyPath(TranslateTransform.XProperty));
_currentStoryboard.Children.Add(itemAnimation);
_currentStoryboard.Completed += (s2, e2) =>
{
((TranslateTransform)newItem.RenderTransform).X = 0;
_currentStoryboard.Stop();
_currentStoryboard = null;
SetSelectedIndex(newIndex, _selectedIndex);
};
_currentStoryboard.Begin();
};
_currentStoryboard.Begin();
}
public void SetSelectedItem(WizardItem item, bool useTransitions = true)
{
SetSelectedIndex(Items.IndexOf(item), useTransitions);
}