//
// ExComboBox.cs
//
// Author:
//       Eric Maupin <ermau@xamarin.com>
//
// Copyright (c) 2012 Xamarin, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.

using System;
using System.Windows;
using SW = System.Windows;
using SWC = System.Windows.Controls;
using System.Windows.Controls;

namespace Xwt.WPFBackend
{
	public class ExComboBox
		: System.Windows.Controls.ComboBox, IWpfWidget
	{
		const string TextBoxTemplateName = "PART_EditableTextBox";

		public event EventHandler TextChanged;
		public event EventHandler TextSelectionChanged;

		public WidgetBackend Backend
		{
			get;
			set;
		}

		public TextBox TextBox { get; private set; }

		protected override SW.Size MeasureOverride (SW.Size constraint)
		{
			var s = base.MeasureOverride (constraint);
			return Backend.MeasureOverride (constraint, s);
		}

		void UpdateTextBox ()
		{
			var newTextBox = GetTemplateChild(TextBoxTemplateName) as TextBox;
			if (TextBox == newTextBox) // no change
				return;
			if (TextBox != null)
			{
				TextBox.TextChanged -= HandleTextBoxTextChanged;
				TextBox.SelectionChanged -= HandleTextBoxSelectionChanged;
			}
			TextBox = newTextBox;
			TextBox.TextChanged += HandleTextBoxTextChanged;
			TextBox.SelectionChanged += HandleTextBoxSelectionChanged;
		}

		public override void OnApplyTemplate()
		{
			base.OnApplyTemplate();
			UpdateTextBox();
		}

		protected override void OnTemplateChanged(SWC.ControlTemplate oldTemplate, SWC.ControlTemplate newTemplate)
		{
			base.OnTemplateChanged(oldTemplate, newTemplate);
			UpdateTextBox();
		}

		protected override void OnTextInput (SW.Input.TextCompositionEventArgs e)
		{
			base.OnTextInput (e);
			OnTextChanged (EventArgs.Empty);
		}

		void HandleTextBoxTextChanged (object sender, EventArgs e)
		{
			OnTextChanged(e);
		}

		protected virtual void OnTextChanged (EventArgs e)
		{
			var changed = TextChanged;
			if (changed != null)
				changed (this, e);
		}

		void HandleTextBoxSelectionChanged(object sender, EventArgs e)
		{
			OnTextSelectionChanged(e);
		}

		protected virtual void OnTextSelectionChanged(EventArgs e)
		{
			if (TextSelectionChanged != null)
				TextSelectionChanged(this, e);
		}
	}
}