mattercontrol/MatterControlLib/Utilities/MarkdigAgg/MarkdownWidget.cs

/*
Copyright(c) 2018, Lars Brubaker, John Lewin
All rights reserved.

Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

1. Redistributions of source code must retain the above copyright notice, this
  list of conditions and the following disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice,
  this list of conditions and the following disclaimer in the documentation
  and/or other materials provided with the distribution.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED.IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

The views and conclusions contained in the software and documentation are those
of the authors and should not be interpreted as representing official policies,
either expressed or implied, of the FreeBSD Project.
*/

using System;
using System.Net;
using MatterHackers.Agg;
using MatterHackers.Agg.UI;
using MatterHackers.Localizations;
using MatterHackers.MatterControl;
using MatterHackers.MatterControl.CustomWidgets;
using MatterHackers.VectorMath;

namespace Markdig.Agg
{
	public class MarkdownWidget : ScrollableWidget
	{
		private string _markDownText = null;
		private FlowLayoutWidget contentPanel;

		private AggMarkdownDocument markdownDocument;
		private ThemeConfig theme;

		public MarkdownWidget(ThemeConfig theme, Uri contentUri, bool scrollContent = true)
			: this(theme, scrollContent)
		{
			markdownDocument.BaseUri = contentUri;

			this.LoadUri(contentUri);
		}

		public MarkdownWidget(ThemeConfig theme, bool scrollContent = true)
			: base(scrollContent)
		{
			markdownDocument = new AggMarkdownDocument();

			this.theme = theme;
			this.HAnchor = HAnchor.Stretch;
			this.ScrollArea.HAnchor = HAnchor.Stretch;
			this.ScrollArea.VAnchor = VAnchor.Fit;
			if (scrollContent)
			{
				this.VAnchor = VAnchor.Stretch;
				this.ScrollArea.Margin = new BorderDouble(0, 0, 15, 0);
			}
			else
			{
				this.VAnchor = VAnchor.Fit;
			}

			var lastScroll = this.TopLeftOffset;
			this.ScrollPositionChanged += (s, e) =>
			{
				lastScroll = TopLeftOffset;
			};

			// make sure as the scrolling area changes height we maintain our current scroll position
			this.ScrollArea.BoundsChanged += (s, e) =>
			{
				TopLeftOffset = lastScroll;
			};

			contentPanel = new FlowLayoutWidget(FlowDirection.TopToBottom)
			{
				HAnchor = HAnchor.Stretch,
				VAnchor = VAnchor.Fit
			};

			this.AddChild(contentPanel);
		}

		public void LoadUri(Uri uri, HelpArticle sourceArticle = null)
		{
			try
			{
				var webClient = new WebClient();
				markdownDocument.BaseUri = uri;

				this.sourceArticle = sourceArticle;

				try
				{
					// put in controls from the feed that show relevant printer information
					WebCache.RetrieveText(uri.ToString(),
						(markDown) =>
						{
							UiThread.RunOnIdle(() =>
							{
								this.Markdown = markDown;
							});
						});
				}
				catch
				{
				}
			}
			catch
			{
				// On error, revert to empty content
				this.Markdown = "";
			}
		}

		private HelpArticle sourceArticle;

		/// <summary>
		/// Gets or sets the markdown to display.
		/// </summary>
		public string Markdown
		{
			get => _markDownText;
			set
			{
				if (_markDownText != value)
				{
					_markDownText = value;

					// Empty self
					contentPanel.CloseAllChildren();

					this.Width = 10;
					this.ScrollPositionFromTop = Vector2.Zero;

					// Add header/edit button for HelpArticle pages
					if (sourceArticle != null)
					{
						var helpArticleHeader = new HelpArticleHeader(sourceArticle, theme, boldFont: true, pointSize: theme.FontSize14, editToolTipText: "Edit Page".Localize());
						helpArticleHeader.EditClicked += (s, e) =>
						{
							ApplicationController.Instance.LaunchBrowser($"https://github.com/MatterHackers/MatterControl-Help/blob/master/input/{sourceArticle.Path}");
							// ApplicationController.Instance.LaunchBrowser($"https://github.com/MatterHackers/MatterControl-Docs/tree/master/docs/Help/{sourceArticle.Path}");
						};
						contentPanel.AddChild(helpArticleHeader);
					}

					// Parse and reconstruct
					markdownDocument.Markdown = value;
					markdownDocument.Parse(contentPanel);
				}
			}
		}

		public string MatchingText
		{
			get => markdownDocument.MatchingText;
			set => markdownDocument.MatchingText = value;
		}
	}
}