/* ****************************************************************************

 *

 * Copyright (c) Microsoft Corporation. 

 *

 * This source code is subject to terms and conditions of the Apache License, Version 2.0. A 

 * copy of the license can be found in the License.html file at the root of this distribution. If 

 * you cannot locate the Apache License, Version 2.0, please send an email to 

 * ironpy@microsoft.com. By using this source code in any fashion, you are agreeing to be bound 

 * by the terms of the Apache License, Version 2.0.

 *

 * You must not remove this notice, or any other, from this software.

 *

 * ***************************************************************************/



using System;

using System.Windows;

using System.Windows.Controls.Primitives;

using System.Windows.Documents;

using System.Windows.Input;

using System.Windows.Media;



namespace Microsoft.IronStudio.Core.Repl {

    internal class ResizingAdorner : Adorner {

        private readonly VisualCollection _visualChildren;

        private readonly Thumb _bottomRight;



        public ResizingAdorner(UIElement adornedElement)

            : base(adornedElement) {

            _visualChildren = new VisualCollection(this);

            _bottomRight = BuildAdornerCorner(Cursors.SizeNWSE, HandleBottomRight);

        }



        private Thumb BuildAdornerCorner(Cursor cursor, DragDeltaEventHandler dragHandler) {

            var thumb = new Thumb();

            // TODO: this thumb should be styled to look like a dotted triangle, 

            // similar to the one you can see on the bottom right corner of 

            // Internet Explorer window

            thumb.Cursor = cursor;

            thumb.Height = thumb.Width = 10;

            thumb.Opacity = 0.40;

            thumb.Background = new SolidColorBrush(Colors.MediumBlue);

            thumb.DragDelta += dragHandler;

            thumb.DragStarted += (s, e) => {

                var handler = ResizeStarted;

                if (handler != null) {

                    handler(this, e);

                }

            };

            thumb.DragCompleted += (s, e) => {

                var handler = ResizeCompleted;

                if (handler != null) {

                    handler(this, e);

                }

            };

            _visualChildren.Add(thumb);

            return thumb;

        }



        private void HandleBottomRight(object sender, DragDeltaEventArgs eventArgs) {

            var thumb = sender as Thumb;

            var element = AdornedElement as FrameworkElement;

            if (element == null || thumb == null) {

                return;

            }



            element.MaxWidth = Math.Max(element.MaxWidth + eventArgs.HorizontalChange, thumb.DesiredSize.Width);

            element.MaxHeight = Math.Max(element.MaxHeight + eventArgs.VerticalChange, thumb.DesiredSize.Height);

            var size = new Size(element.MaxWidth, element.MaxHeight);

            AdornedElement.Measure(size);

        }



        protected override Size ArrangeOverride(Size finalSize) {

            var desiredWidth = AdornedElement.DesiredSize.Width;

            var desiredHeight = AdornedElement.DesiredSize.Height;

            var adornerWidth = DesiredSize.Width;

            var adornerHeight = DesiredSize.Height;



            _bottomRight.Arrange(new Rect((desiredWidth - adornerWidth) / 2,

                (desiredHeight - adornerHeight) / 2, adornerWidth, adornerHeight));



            return finalSize;

        }



        protected override int VisualChildrenCount {

            get { return _visualChildren.Count; }

        }



        protected override Visual GetVisualChild(int index) {

            return _visualChildren[index];

        }



        public event RoutedEventHandler ResizeStarted;

        public event RoutedEventHandler ResizeCompleted;

    }

}