using System;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Controls.Primitives;

namespace GitHub.UI

{

public class DropDownButton : ContentControl

{

public static readonly DependencyProperty AutoCloseOnClickProperty =

DependencyProperty.Register(

"AutoCloseOnClick",

typeof(bool),

typeof(DropDownButton),

new FrameworkPropertyMetadata(true));

public static readonly DependencyProperty DropDownContentProperty =

DependencyProperty.Register(nameof(DropDownContent), typeof(object), typeof(DropDownButton));

public static readonly DependencyProperty IsOpenProperty =

Popup.IsOpenProperty.AddOwner(typeof(DropDownButton));

Button button;

Popup popup;

static DropDownButton()

{

DefaultStyleKeyProperty.OverrideMetadata(

typeof(DropDownButton),

new FrameworkPropertyMetadata(typeof(DropDownButton)));

}

public bool AutoCloseOnClick

{

get { return (bool)GetValue(AutoCloseOnClickProperty); }

set { SetValue(AutoCloseOnClickProperty, value); }

}

public object DropDownContent

{

get { return GetValue(DropDownContentProperty); }

set { SetValue(DropDownContentProperty, value); }

}

public bool IsOpen

{

get { return (bool)GetValue(IsOpenProperty); }

set { SetValue(IsOpenProperty, value); }

}

public event EventHandler PopupOpened;

public event EventHandler PopupClosed;

public override void OnApplyTemplate()

{

base.OnApplyTemplate();

button = (Button)Template.FindName("PART_Button", this);

popup = (Popup)Template.FindName("PART_Popup", this);

button.Click += ButtonClick;

popup.Opened += OnPopupOpened;

popup.Closed += OnPopupClosed;

popup.AddHandler(MouseUpEvent, new RoutedEventHandler(PopupMouseUp), true);

}

void ButtonClick(object sender, RoutedEventArgs e)

{

IsOpen = true;

}

private void OnPopupOpened(object sender, EventArgs e)

{

IsHitTestVisible = false;

PopupOpened?.Invoke(this, e);

}

private void OnPopupClosed(object sender, EventArgs e)

{

IsOpen = false;

IsHitTestVisible = true;

PopupClosed?.Invoke(this, e);

}

private void PopupMouseUp(object sender, RoutedEventArgs e)

{

if (AutoCloseOnClick)

{

IsOpen = false;

}

}

}

}