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c#visual-studioadornment
cubrman
cubrman

Reputation: 946

C#'s scroll bar adornments?

When writing a Visual Studio extension, is there any way to influence how it renders map-mode scroll bar for c#?

enter image description here

Upvotes: 2

Views: 1127

Answers (1)

cubrman
cubrman

Reputation: 946

I don't have time for the full answer, but I will write the short one because there is next to zero info about it on the net:

  1. Create VSIX solution.
  2. Add Item and in the "Extensibility" category choose "Editor margin"

  3. In the "[yourEditorMarginName]Factory.cs" file that was created alonside the margin file after you did step 2 set the following lines:

        [MarginContainer(PredefinedMarginNames.VerticalScrollBar)]
    [Order(Before = PredefinedMarginNames.LineNumber)]

  4. Go back to the "[yourEditorMarginName].cs" file. Make sure that you remove the following lines in the constructor:

        this.Height = 20;
    this.ClipToBounds = true;
    this.Width = 200;

  5. Now you received a reference to IWpfTextView inside the constructor, sign up to its OnLayoutChanged event (or use some other event that suits you):

        TextView.LayoutChanged += OnLayoutChanged;

  6. In the OnLayoutChanged, you can do the following to add a rectangle adornment:

        var rect = new Rectangle();
    double bottom;
    double firstLineTop;
    MapLineToPixels([someLineYouNeedToHighlight], out firstLineTop, out bottom);
    SetTop(rect, firstLineTop);
    SetLeft(rect, 0);
    rect.Height = bottom - firstLineTop;
    rect.Width = [yourWidth];
    Color color = [your Color];
    rect.Fill = new SolidColorBrush(color);

    Children.Add(rect);

  7. And here is MapLineToPixels():

        private void MapLineToPixels(ITextSnapshotLine line, out double top, out double bottom)
    {
    double mapTop = ScrollBar.Map.GetCoordinateAtBufferPosition(line.Start) - 0.5;
    double mapBottom = ScrollBar.Map.GetCoordinateAtBufferPosition(line.End) + 0.5;
    top = Math.Round(ScrollBar.GetYCoordinateOfScrollMapPosition(mapTop)) - 2.0;
    bottom = Math.Round(ScrollBar.GetYCoordinateOfScrollMapPosition(mapBottom)) + 2.0;
    }

  8. Yeah the ScrollBar variable is something you can get this way:

    public ScrollbarMargin(IWpfTextView textView, IWpfTextViewMargin marginContainer/*, MarginCore marginCore*/)
{
    ITextViewMargin scrollBarMargin = marginContainer.GetTextViewMargin(PredefinedMarginNames.VerticalScrollBar);
    ScrollBar = (IVerticalScrollBar)scrollBarMargin;

Upvotes: 6

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