﻿// 
// TextEntryBackend.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 System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using Xwt.Backends;
using Xwt.WPFBackend.Utilities;

namespace Xwt.WPFBackend
{
    public class MultiLineTextEntryBackend : WidgetBackend, IMultiLineTextEntryBackend
    {
        bool multiline;

        PlaceholderTextAdorner Adorner
        {
            get;
            set;
        }

        public MultiLineTextEntryBackend()
        {
            Widget = new ExTextBox { IsReadOnlyCaretVisible = true };
            Adorner = new PlaceholderTextAdorner(TextBox);
            TextBox.Loaded += TextBox_Loaded;
            TextBox.VerticalContentAlignment = VerticalAlignment.Center;
            MultiLine = true;
            TextBox.TextWrapping = TextWrapping.Wrap;
        }


        void TextBox_Loaded(object sender, RoutedEventArgs e)
        {
            var layer = AdornerLayer.GetAdornerLayer(TextBox);

            if (layer != null)
                layer.Add(Adorner);

            TextBox.Loaded -= TextBox_Loaded;
        }
        protected override double DefaultNaturalWidth
        {
            get { return -1; }
        }

        public virtual string Text
        {
            get { return TextBox.Text; }
            set { TextBox.Text = value; }
        }

        public bool ReadOnly
        {
            get { return TextBox.IsReadOnly; }
            set { TextBox.IsReadOnly = true; }
        }

        public bool MultiLine
        {
            get { return multiline; }
            set
            {
                if (multiline != value)
                {
                    multiline = value;
                    if (multiline)
                    {
                        TextBox.VerticalContentAlignment = VerticalAlignment.Top;
                        TextBox.AcceptsReturn = true;
                        TextBox.TextWrapping = TextWrapping.Wrap;
                    }
                    else
                    {
                        TextBox.VerticalContentAlignment = VerticalAlignment.Center;
                        TextBox.AcceptsReturn = false;
                        TextBox.TextWrapping = TextWrapping.NoWrap;
                    }
                }
            }
        }

        public override void EnableEvent(object eventId)
        {
            base.EnableEvent(eventId);

            if (eventId is TextEntryEvent)
            {
                switch ((TextEntryEvent)eventId)
                {
                    // TODO: Should we ignore this for placeholder changes?
                    case TextEntryEvent.Changed:
                        TextBox.TextChanged += OnTextChanged;
                        break;
                }
            }
        }

        public override void DisableEvent(object eventId)
        {
            base.DisableEvent(eventId);

            if (eventId is TextEntryEvent)
            {
                switch ((TextEntryEvent)eventId)
                {
                    case TextEntryEvent.Changed:
                        TextBox.TextChanged -= OnTextChanged;
                        break;
                }
            }
        }

        protected ExTextBox TextBox
        {
            get { return (ExTextBox)Widget; }
        }

        protected new ITextEntryEventSink EventSink
        {
            get { return (ITextEntryEventSink)base.EventSink; }
        }

        private void OnTextChanged(object s, TextChangedEventArgs e)
        {
            Context.InvokeUserCode(EventSink.OnChanged);
        }
    }
}