public static void SetIndexChangeable(this Control control, StackPanel parentStackPanel, IndexChangedDelegate OnIndexChanged = null)
{
Control grabbedItem = null;
int grabbedIndex = 0;
bool onDragging = false;
control.MouseDown += (object sender, MouseButtonEventArgs e) => {
if (e.ChangedButton == MouseButton.Left)
{
onDragging = true;
Mouse.Capture(control);
grabbedItem = control;
grabbedIndex = parentStackPanel.Children.IndexOf(control);
}
};
control.MouseMove += (object sender, MouseEventArgs e) => {
if (!onDragging)
{
return;
}
//Find Cursor Index
int newIndex = -1;
Control item;
int count = parentStackPanel.Children.Count;
for (int i = 0; i < count; ++i)
{
item = (Control)parentStackPanel.Children[i];
float itemHalfHeight = (float)(item.ActualHeight * 0.5f);
if (MouseInput.AbsolutePosition.y < item.GetAbsolutePosition(new Vector2(0, itemHalfHeight)).y)
{
newIndex = i;
break;
}
}
if (newIndex == -1)
{
newIndex = count;
}
if (newIndex != grabbedIndex)
{
if (newIndex > grabbedIndex)
{
--newIndex;
}
parentStackPanel.Children.Remove(grabbedItem);
parentStackPanel.Children.Insert(newIndex, grabbedItem);
OnIndexChanged?.Invoke(grabbedIndex, newIndex);
grabbedIndex = newIndex;
}
};
control.MouseUp += (object sender, MouseButtonEventArgs e) => {
if (e.ChangedButton == MouseButton.Left)
{
onDragging = false;
Mouse.Capture(null);
}
};
}
public static void SetIndexChangeableContext <ElementType>(this StackPanel context, IndexChangedDelegate OnIndexChanged = null) where ElementType : FrameworkElement
{
ElementType grabbedItem = null;
int grabbedIndex = 0;
bool onDragging = false;
context.MouseDown += (object sender, MouseButtonEventArgs e) => {
if (e.ChangedButton != MouseButton.Left)
{
return;
}
if (e.OriginalSource is FrameworkElement)
{
grabbedItem = GetPressedItem((FrameworkElement)e.OriginalSource);
}
if (grabbedItem == null)
{
return;
}
int initGrabbedIndex = context.Children.IndexOf(grabbedItem);
grabbedIndex = initGrabbedIndex;
Mouse.Capture(grabbedItem);
onDragging = true;
};
context.MouseMove += (object sender, MouseEventArgs e) => {
if (!onDragging)
{
return;
}
//Find Cursor Index
int newIndex = -1;
FrameworkElement item;
int count = context.Children.Count;
for (int i = 0; i < count; ++i)
{
item = (FrameworkElement)context.Children[i];
float itemHalfHeight = (float)(item.ActualHeight * 0.5f);
if (MouseInput.AbsolutePosition.y < item.GetAbsolutePosition(new Vector2(0, itemHalfHeight)).y)
{
newIndex = i;
break;
}
}
if (newIndex == -1)
{
newIndex = count;
}
if (newIndex != grabbedIndex)
{
if (newIndex > grabbedIndex)
{
--newIndex;
}
context.Children.Remove(grabbedItem);
context.Children.Insert(newIndex, grabbedItem);
OnIndexChanged?.Invoke(grabbedIndex, newIndex);
grabbedIndex = newIndex;
}
};
context.MouseUp += (object sender, MouseButtonEventArgs e) => {
if (e.ChangedButton != MouseButton.Left)
{
return;
}
onDragging = false;
Mouse.Capture(null);
};
ElementType GetPressedItem(FrameworkElement pressedElement)
{
//부모 트리로 Item이 나올 때까지 탐색하는 함수이다.
DependencyObject parent = pressedElement.Parent;
if (pressedElement is ElementType && parent == context)
{
return(pressedElement as ElementType);
}
else if (parent != null && !(parent is Window) && parent is FrameworkElement)
{
return(GetPressedItem((FrameworkElement)parent));
}
else
{
return(null);
}
}
}
