sources/Google.Solutions.Mvvm/Controls/PropertyGridExtensions.cs

//
// Copyright 2020 Google LLC
//
// Licensed to the Apache Software Foundation (ASF) under one
// or more contributor license agreements.  See the NOTICE file
// distributed with this work for additional information
// regarding copyright ownership.  The ASF licenses this file
// to you under the Apache License, Version 2.0 (the
// "License"); you may not use this file except in compliance
// with the License.  You may obtain a copy of the License at
// 
//   http://www.apache.org/licenses/LICENSE-2.0
// 
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied.  See the License for the
// specific language governing permissions and limitations
// under the License.
//

using System.Diagnostics;
using System.Linq;
using System.Windows.Forms;

namespace Google.Solutions.Mvvm.Controls
{
    public static class PropertyGridExtensions
    {
        public static void EnableRichTextDescriptions(this PropertyGrid propertyGrid)
        {
            var rtfLabel = new RichTextBox()
            {
                Multiline = true,
                WordWrap = true,
                ReadOnly = true,
                BorderStyle = BorderStyle.None,
                DetectUrls = true,
                BackColor = propertyGrid.HelpBackColor,
                ForeColor = propertyGrid.HelpForeColor
            };

            rtfLabel.SetPadding(3);
            rtfLabel.LinkClicked += (sender, args) =>
            {
                using (Process.Start(args.LinkText))
                { }
            };

            // Add RTF box as child control.
            var docCommentControl = propertyGrid.Controls[0];
            docCommentControl.Controls.Add(rtfLabel);
            docCommentControl.Controls.SetChildIndex(rtfLabel, 0);

            // Overlay existing description label by RTF box.
            var descriptionLabel = docCommentControl
                .Controls
                .OfType<Label>()
                .Last();
            descriptionLabel.TextChanged += delegate {
                rtfLabel.Text = descriptionLabel.Text;
            };

            descriptionLabel.SizeChanged += delegate {
                rtfLabel.Size = descriptionLabel.Size;
            };

            descriptionLabel.LocationChanged += delegate {
                rtfLabel.Location = descriptionLabel.Location;
            };
        }
    }
}