PowerToys/src/modules/previewpane/MarkdownPreviewHandler/MarkdownPreviewHandlerControl.cs
Divyansh Srivastava c2e219b446
Display infobar for blocked relative image path (#1695)
* Updated Parsing extension to show infobar when relative URL isblocked and updated corresponding tests

* Updated Controller to display infobar when html img tag is embedded in markdown
2020-03-26 15:17:28 -07:00

187 lines
9.0 KiB
C#

// Copyright (c) Microsoft Corporation
// The Microsoft Corporation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
using System;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Windows.Forms;
using Common;
using Markdig;
using MarkdownPreviewHandler.Properties;
using PreviewHandlerCommon;
namespace MarkdownPreviewHandler
{
/// <summary>
/// Win Form Implementation for Markdown Preview Handler.
/// </summary>
public class MarkdownPreviewHandlerControl : FormHandlerControl
{
/// <summary>
/// Extension to modify markdown AST.
/// </summary>
private readonly HTMLParsingExtension extension;
/// <summary>
/// Markdig Pipeline builder.
/// </summary>
private readonly MarkdownPipelineBuilder pipelineBuilder;
/// <summary>
/// Markdown HTML header.
/// </summary>
private readonly string htmlHeader = "<!doctype html><style>body{width:100%;margin:0;font-family:-apple-system,BlinkMacSystemFont,\"Segoe UI\",Roboto,\"Helvetica Neue\",Arial,\"Noto Sans\",sans-serif,\"Apple Color Emoji\",\"Segoe UI Emoji\",\"Segoe UI Symbol\",\"Noto Color Emoji\";font-size:1rem;font-weight:400;line-height:1.5;color:#212529;text-align:left;background-color:#fff}.container{padding:5%}body img{max-width:100%;height:auto}body h1,body h2,body h3,body h4,body h5,body h6{margin-top:24px;margin-bottom:16px;font-weight:600;line-height:1.25}body h1,body h2{padding-bottom:.3em;border-bottom:1px solid #eaecef}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,Helvetica,Arial,sans-serif,Apple Color Emoji,Segoe UI Emoji}body h3{font-size:1.25em}body h4{font-size:1em}body h5{font-size:.875em}body h6{font-size:.85em;color:#6a737d}pre{font-family:SFMono-Regular,Consolas,Liberation Mono,Menlo,monospace;background-color:#f6f8fa;border-radius:3px;padding:16px;font-size:85%}a{color:#0366d6}strong{font-weight:600}em{font-style:italic}code{padding:.2em .4em;margin:0;font-size:85%;background-color:#f6f8fa;border-radius:3px}hr{border-color:#EEE -moz-use-text-color #FFF;border-style:solid none;border-width:.5px 0;margin:18px 0}table{display:block;width:100%;overflow:auto;border-spacing:0;border-collapse:collapse}tbody{display:table-row-group;vertical-align:middle;border-color:inherit;display:table-row;vertical-align:inherit;border-color:inherit}table tr{background-color:#fff;border-top:1px solid #c6cbd1}tr{display:table-row;vertical-align:inherit;border-color:inherit}table td,table th{padding:6px 13px;border:1px solid #dfe2e5}th{font-weight:600;display:table-cell;vertical-align:inherit;font-weight:bold;text-align:-internal-center}thead{display:table-header-group;vertical-align:middle;border-color:inherit}td{display:table-cell;vertical-align:inherit}code,pre,tt{font-family:SFMono-Regular,Menlo,Monaco,Consolas,\"Liberation Mono\",\"Courier New\",monospace;color:#24292e;overflow-x:auto}pre code{font-size:inherit;color:inherit;word-break:normal}blockquote{background-color:#fff;border-radius:3px;padding:15px;font-size:14px;display:block;margin-block-start:1em;margin-block-end:1em;margin-inline-start:40px;margin-inline-end:40px;padding:0 1em;color:#6a737d;border-left:.25em solid #dfe2e5}</style><body><div class=\"container\">";
/// <summary>
/// Markdown HTML footer.
/// </summary>
private readonly string htmlFooter = "</div></body></html>";
/// <summary>
/// RichTextBox control to display if external images are blocked.
/// </summary>
private RichTextBox infoBar;
/// <summary>
/// Extended Browser Control to display markdown html.
/// </summary>
private WebBrowserExt browser;
/// <summary>
/// True if external image is blocked, false otherwise.
/// </summary>
private bool infoBarDisplayed = false;
/// <summary>
/// Initializes a new instance of the <see cref="MarkdownPreviewHandlerControl"/> class.
/// </summary>
public MarkdownPreviewHandlerControl()
{
this.extension = new HTMLParsingExtension(this.ImagesBlockedCallBack);
this.pipelineBuilder = new MarkdownPipelineBuilder().UseAdvancedExtensions().UseEmojiAndSmiley();
this.pipelineBuilder.Extensions.Add(this.extension);
}
/// <summary>
/// Start the preview on the Control.
/// </summary>
/// <param name="dataSource">Path to the file.</param>
public override void DoPreview<T>(T dataSource)
{
this.InvokeOnControlThread(() =>
{
try
{
this.infoBarDisplayed = false;
StringBuilder sb = new StringBuilder();
string filePath = dataSource as string;
string fileText = File.ReadAllText(filePath);
this.extension.BaseUrl = Path.GetDirectoryName(filePath);
Regex rgx = new Regex(@"<[ ]*img.*>");
if (rgx.IsMatch(fileText))
{
this.infoBarDisplayed = true;
}
MarkdownPipeline pipeline = this.pipelineBuilder.Build();
string parsedMarkdown = Markdown.ToHtml(fileText, pipeline);
sb.AppendFormat("{0}{1}{2}", this.htmlHeader, parsedMarkdown, this.htmlFooter);
string markdownHTML = sb.ToString();
this.browser = new WebBrowserExt
{
DocumentText = markdownHTML,
Dock = DockStyle.Fill,
IsWebBrowserContextMenuEnabled = false,
ScriptErrorsSuppressed = true,
ScrollBarsEnabled = true,
AllowNavigation = false,
};
this.Controls.Add(this.browser);
if (this.infoBarDisplayed)
{
this.infoBar = this.GetTextBoxControl(Resources.BlockedImageInfoText);
this.Controls.Add(this.infoBar);
}
this.Resize += this.FormResized;
base.DoPreview(dataSource);
MarkdownTelemetry.Log.MarkdownFilePreviewed();
}
catch (Exception e)
{
MarkdownTelemetry.Log.MarkdownFilePreviewError(e.Message);
this.infoBarDisplayed = true;
this.infoBar = this.GetTextBoxControl(Resources.MarkdownNotPreviewedError);
this.Resize += this.FormResized;
this.Controls.Clear();
this.Controls.Add(this.infoBar);
base.DoPreview(dataSource);
}
});
}
/// <summary>
/// Gets a textbox control.
/// </summary>
/// <param name="message">Message to be displayed in textbox.</param>
/// <returns>An object of type <see cref="RichTextBox"/>.</returns>
private RichTextBox GetTextBoxControl(string message)
{
RichTextBox richTextBox = new RichTextBox
{
Text = message,
BackColor = Color.LightYellow,
Multiline = true,
Dock = DockStyle.Top,
ReadOnly = true,
};
richTextBox.ContentsResized += this.RTBContentsResized;
richTextBox.ScrollBars = RichTextBoxScrollBars.None;
richTextBox.BorderStyle = BorderStyle.None;
return richTextBox;
}
/// <summary>
/// Callback when RichTextBox is resized.
/// </summary>
/// <param name="sender">Reference to resized control.</param>
/// <param name="e">Provides data for the resize event.</param>
private void RTBContentsResized(object sender, ContentsResizedEventArgs e)
{
RichTextBox richTextBox = (RichTextBox)sender;
richTextBox.Height = e.NewRectangle.Height + 5;
}
/// <summary>
/// Callback when form is resized.
/// </summary>
/// <param name="sender">Reference to resized control.</param>
/// <param name="e">Provides data for the event.</param>
private void FormResized(object sender, EventArgs e)
{
if (this.infoBarDisplayed)
{
this.infoBar.Width = this.Width;
}
}
/// <summary>
/// Callback when image is blocked by extension.
/// </summary>
private void ImagesBlockedCallBack()
{
this.infoBarDisplayed = true;
}
}
}