/IronPython_Main/Tools/IronStudio/IronStudioCore/IronStudioCore/Repl/ReplPrompt.cs

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

 *

 * 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.Collections.Generic;

using System.ComponentModel.Composition;

using System.Windows;

using System.Windows.Controls;

using System.Windows.Media;

using Microsoft.Scripting.Utils;

using Microsoft.VisualStudio.Text;

using Microsoft.VisualStudio.Text.Editor;

using Microsoft.VisualStudio.Text.Formatting;

using Microsoft.VisualStudio.Text.Tagging;

using Microsoft.VisualStudio.Utilities;



namespace Microsoft.IronStudio.Core.Repl {

    /// <summary>

    /// Any <see cref="ITextBuffer"/> with content type <see cref="CoreConstants.DlrContentTypeName"/>, role <see cref="CoreConstants.ReplTextViewRole"/> 

    /// and property <see cref="IReplPromptProvider"/> gets prompt glyphs in its glyph margin.

    /// </summary>

    public interface IReplPromptProvider {

        /// <summary>

        /// The prompt text to display in the margin.

        /// </summary>

        string/*!*/ Prompt { get; }



        /// <summary>

        /// The control that hosts the text view.

        /// </summary>

        Control/*!*/ HostControl { get; }



        /// <summary>

        /// Should we draw a prompt glyph for given line.

        /// </summary>

        bool HasPromptForLine(ITextSnapshot/*!*/ snapshot, int lineNumber);



        /// <summary>

        /// Notifies glyph margin that prompt glyph(s) need to be updated.

        /// </summary>

        event Action<SnapshotSpan> PromptChanged;

    }



    /// <summary>

    /// Implements prompt glyphs in a GlyphMargin. 

    /// </summary>

    internal static class ReplPrompt {

        internal const string GlyphName = "ReplPromptGlyph";



        internal sealed class ReplGlyphTag : IGlyphTag {

            internal static readonly ReplGlyphTag Instance = new ReplGlyphTag();

        }



        internal sealed class Tagger : ITagger<ReplGlyphTag> {

            private readonly IReplPromptProvider/*!*/ _promptProvider;



            public Tagger(IReplPromptProvider/*!*/ promptProvider) {

                Assert.NotNull(promptProvider);

                _promptProvider = promptProvider;

                _promptProvider.PromptChanged += new Action<SnapshotSpan>((span) => {

                    var tagsChanged = TagsChanged;

                    if (tagsChanged != null) {

                        tagsChanged(this, new SnapshotSpanEventArgs(span));

                    }

                });

            }



            public IEnumerable<ITagSpan<ReplGlyphTag>>/*!*/ GetTags(NormalizedSnapshotSpanCollection/*!*/ spans) {

                foreach (SnapshotSpan span in spans) {

                    if (_promptProvider.HasPromptForLine(span.Snapshot, span.Start.GetContainingLine().LineNumber)) {

                        yield return new TagSpan<ReplGlyphTag>(span, ReplGlyphTag.Instance);

                    }

                }

            }



            public event EventHandler<SnapshotSpanEventArgs> TagsChanged;

        }



        [Export(typeof(ITaggerProvider))]

        [TagType(typeof(ReplGlyphTag))]

        [ContentType(CoreConstants.DlrContentTypeName)]

        [TextViewRole(CoreConstants.ReplTextViewRole)]

        internal sealed class TaggerProvider : ITaggerProvider {

            public ITagger<T> CreateTagger<T>(ITextBuffer/*!*/ buffer) where T : ITag {

                IReplPromptProvider promptProvider;

                if (buffer.Properties.TryGetProperty(typeof(IReplPromptProvider), out promptProvider)) {

                    return (ITagger<T>)(object)new Tagger(promptProvider);

                }

                return null;

            }

        }



        internal sealed class GlyphFactory : IGlyphFactory {

            private readonly IReplPromptProvider/*!*/ _promptProvider;

            private static readonly FontFamily _Consolas = new FontFamily("Consolas");



            public GlyphFactory(IReplPromptProvider/*!*/ promptProvider) {

                Assert.NotNull(promptProvider);

                _promptProvider = promptProvider;

            }



            public UIElement/*!*/ GenerateGlyph(IWpfTextViewLine/*!*/ line, IGlyphTag tag) {

                TextBlock block = new TextBlock();

                block.Text = _promptProvider.Prompt;

                block.Foreground = _promptProvider.HostControl.Foreground;

                block.FontSize = _promptProvider.HostControl.FontSize;

                block.FontFamily = _Consolas; // TODO: get the font family from the editor?

                return block;

            }

        }



        [Export(typeof(IGlyphFactoryProvider))]

        [Name(GlyphName)]

        [Order(After = "VsTextMarker")]

        [TagType(typeof(ReplGlyphTag))]

        [ContentType(CoreConstants.DlrContentTypeName)]

        [TextViewRole(CoreConstants.ReplTextViewRole)]

        internal sealed class GlyphFactoryProvider : IGlyphFactoryProvider {

            public IGlyphFactory GetGlyphFactory(IWpfTextView/*!*/ view, IWpfTextViewMargin/*!*/ margin) {

                IReplPromptProvider promptProvider;

                if (view.TextBuffer.Properties.TryGetProperty(typeof(IReplPromptProvider), out promptProvider)) {

                    return new GlyphFactory(promptProvider);

                }

                return null;

            }

        }

    }

}