Develop Reference

VSIX: IErrorTag tooltip content not displaying

I am trying to write a code analysis extension for visual studio using MEF. I have implemented the ITagger interface for an IErrorTag along with the required ITaggerProvider. As a result, i get the expected squiggles in the editor window for the issues my code analysis finds. However, when hovering above the squiggles with the mouse, the respective tooltip content is never displayed.
Here is a minimalistic example which has the same problem:
using Microsoft.VisualStudio.Text.Adornments;
using Microsoft.VisualStudio.Text.Editor;
using Microsoft.VisualStudio.Text.Tagging;
using System;
using System.Collections.Generic;
namespace CodeAnalyzer
{
struct DummyIssue
{
public int Line; // one based line
public string ToolTip;
public DummyIssue(int line, string toolTip)
{
Line = line;
ToolTip = toolTip;
}
}
internal class DummyCodeCheckTagger : ITagger<IErrorTag>
{
readonly List<DummyIssue> mIssues;
readonly ITextView TextView;
public DummyCodeCheckTagger(ITextView textView)
{
TextView = textView;
mIssues = new List<DummyIssue>
{
new DummyIssue(1, "asldfjoqwet"),
new DummyIssue(7, "ASASDAER")
};
textView.LayoutChanged += Update;
}
public event EventHandler<SnapshotSpanEventArgs> TagsChanged;
private void Update(object sender, TextViewLayoutChangedEventArgs args)
{
TagsChanged?.Invoke(this, new SnapshotSpanEventArgs(new SnapshotSpan(args.NewSnapshot, 0, args.NewSnapshot.Length)));
}
IEnumerable<ITagSpan<IErrorTag>> ITagger<IErrorTag>.GetTags(NormalizedSnapshotSpanCollection spans)
{
var issues = mIssues;
foreach (var span in spans)
{
foreach (var issue in issues)
{
int zeroBasedLine = issue.Line - 1;
ITextSnapshotLine snapshotLine = TextView.TextSnapshot.GetLineFromLineNumber(zeroBasedLine);
SnapshotSpan snapshotSpan = snapshotLine.Extent;
if (spans.IntersectsWith(snapshotSpan))
{
yield return new TagSpan<IErrorTag>(snapshotSpan, new ErrorTag(PredefinedErrorTypeNames.SyntaxError, issue.ToolTip));
}
}
}
}
}
}
The result looks like this:
tooltip not displaying
What am i missing to get the tooltip displayed?

Fater's comment above led me to think about the problem again. Since i already tried the suggestions in the document posted by fater without success, i started thinking if the problem could be somewhere else.
It turns out that the ITagger implementation was not the problem, but the ITaggerProvider implementation caused the strange behavior. For that,
I pretty much followed the VSIX ErrorList example implementing a SpellChecker, which contains the following code
/// <summary>
/// Create a tagger that does spell checking on the view/buffer combination.
/// </summary>
public ITagger<T> CreateTagger<T>(ITextView textView, ITextBuffer buffer) where T : ITag
{
ITagger<T> tagger = null;
// Only attempt to spell check on the view's edit buffer (and multiple views could have that buffer open simultaneously so
// only create one instance of the spell checker.
if ((buffer == textView.TextBuffer) && (typeof(T) == typeof(IErrorTag)))
{
var spellChecker = buffer.Properties.GetOrCreateSingletonProperty(typeof(SpellChecker), () => new SpellChecker(this, textView, buffer));
// This is a thin wrapper around the SpellChecker that can be disposed of without shutting down the SpellChecker
// (unless it was the last tagger on the spell checker).
tagger = new SpellCheckerTagger(spellChecker) as ITagger<T>;
}
return tagger;
}
The point is, that the code above only creates an ITagger for a certain view. In that case the created tagger is used only for providing the squiggles in the editor window view. Visual Studio uses a different tagger instance for providing the tooltips for the squiggles and another tagger instance for coloring the scroll bar in the editor window. I had assumed that this would be done by one single tagger instance.

Why does MonoTouch.Dialog use public fields for some Element options, and public properties for others

I am trying to get a StringElement's 'Value' to update in the UI when I set it after already setting up the DVC.
e.g:
public partial class TestDialog : DialogViewController
{
public TestDialog() : base (UITableViewStyle.Grouped, null)
{
var stringElement = new StringElement("Hola");
stringElement.Value = "0 Taps";
int tapCount = 0;
stringElement.Tapped += () => stringElement.Value = ++tapCount + " Taps";
Root = new RootElement("TestDialog")
{
new Section("First Section")
{
stringElement,
},
};
}
}
However the StringElement.Value is just a public field, and is only written to the UICell during initialization when Element.GetCell is called.
Why isn't it a property, with logic in the setter to update the UICell (like the majority of Elements, e.g. EntryElement.Value):
public string Value
{
get { return val; }
set
{
val = value;
if (entry != null)
entry.Text = value;
}
}
EDIT :
I made my own version of StringElement, derived from Element (basically just copied the source code from here verbatim)
I then changed it to take a class scoped reference to the cell created in GetCell, rather than function scoped. Then changed the Value field to a property:
public string Value
{
get { return val; }
set
{
val = value;
if (cell != null)
{
// (The below is copied direct from GetCell)
// The check is needed because the cell might have been recycled.
if (cell.DetailTextLabel != null)
cell.DetailTextLabel.Text = Value == null ? "" : Value;
}
}
}
It works in initial testing. However I am not sure on whether taking a reference to the cell is allowed, none of the other elements seem to do it (they only take references to control's placed within the cells). Is it possible that multiple 'live'* cell's are created based on the one MonoTouch.Dialog.Element instance?
*I say live to indicate cells currently part of the active UI. I did notice when navigating back to the dialog from a child dialog the GetCell method is invoked again and a new cell created based on the Element, but this is still a 1-1 between the element and the live cell.

For the main question:
Why does MonoTouch.Dialog use public fields for some Element options, and public properties for others?
I've been through the code, and I don't think there's a consistent reason for use of either.
The Dialog project was not part of the MonoTouch project initially - I don't think Miguel knew how useful it was going to turn out when he started wrote and grew it - I think he was more focussed on writing other apps like TweetStation at the time.
I know of several people (including me!) who have branched the code and adapted it for their purposes. I would guess at some future point Xamarin might write a 2.0 version with stricter coding standards.
Taking references to live cells
For limited use you can do this... but in general don't.
The idea of the table view is that cells get reused when the user scrolls up and down - especially in order to save memory and ui resources. Because of this is a long list, multiple elements might get references to the same cell.
If you do want to cache a cell reference then you probably should override GetCell() so that it never tries to reuse existing cells (never calls DequeueReusableCell)
Alternatively, you could try to change some code in the base Element class in order to find out if the Element has a current attached cell - this is what CurrentAttachedCell does in my branch of Dialog https://github.com/slodge/MvvmCross/blob/master/Cirrious/Cirrious.MvvmCross.Dialog/Dialog/Elements/Element.cs (but that branch has other added functions and dependencies so you probably won't want to use it for this current work!)

How to write an add-in to change text color in Visual Studio editor?

After searching for a long time for a simple way of changing the text color of a #region directive in Visual Studio, I've concluded there is no easy way of doing so.
I know how to change the #region statement color, and how to change the collapsed region color, but I want to change the color of the text with the region description. So:
#region Some text <--- all this text should be in a different color
public void Test()
{
}
#endregion <--- this too
It seems a lot of people are looking for something like this - see How to change the color of expanded regions' titles in VS2008?.
So I've been looking at writing a simple Visual Studio add-in to change the color.
However, it's more complicated than I thought it would be, with classes like Snapshot, Tagger, Classifier, WpfTextViewCreationListener, AdornmentLayer etc.
Simply put, I don't know where to start! I followed a couple of tutorials at the MSDN site, but they seem too complicated for what I'm trying to do.
Can someone point me to the most simple way of doing this? Ie. which classes/methods/events within the VS SDK I should use. I don't mind if the color is not customisable via the UI etc either. I'm using VS2010.
Edit: Just had the mztools website recommended to me; I'll take a look there too. Also noticed that StackOverflow's syntax highlighting of regions is pretty much exactly what I want!

I eventually came up with a solution, at least for VS2010.
Whilst I have used this for coloring '#region' and '#endregion' tags, a similar solution ought to be applicable for any text content in a Visual Studio window.
It seems that this sort of problem can be resolved by creating a IViewTaggerProvider which will 'tag' parts of the source code with a 'classification'.
Visual Studio will provide a style for text tagged with that classification which can then be changed by the user to the desired style via Tools > Options... > Environment > Fonts and Colors.
The Tagger provider looks like:
[Export(typeof(IViewTaggerProvider))]
[ContentType("any")]
[TagType(typeof(ClassificationTag))]
public sealed class RegionTaggerProvider : IViewTaggerProvider
{
[Import]
public IClassificationTypeRegistryService Registry;
[Import]
internal ITextSearchService TextSearchService { get; set; }
public ITagger<T> CreateTagger<T>(ITextView textView, ITextBuffer buffer) where T : ITag
{
if (buffer != textView.TextBuffer)
return null;
var classType = Registry.GetClassificationType("region-foreground");
return new RegionTagger(textView, TextSearchService, classType) as ITagger<T>;
}
}
This creates an ITagger object, which, given a Visual Studio text view, will tag parts of the text with the given classification type. Note that this will work for all text views (i.e. source code editor, 'Find Results' windows etc.). It may be possible to change this by editing the ContentType attribute (to just C#?).
The classification type (in this case "region-foreground") is defined as:
public static class TypeExports
{
[Export(typeof(ClassificationTypeDefinition))]
[Name("region-foreground")]
public static ClassificationTypeDefinition OrdinaryClassificationType;
}
[Export(typeof(EditorFormatDefinition))]
[ClassificationType(ClassificationTypeNames = "region-foreground")]
[Name("region-foreground")]
[UserVisible(true)]
[Order(After = Priority.High)]
public sealed class RegionForeground : ClassificationFormatDefinition
{
public RegionForeground()
{
DisplayName = "Region Foreground";
ForegroundColor = Colors.Gray;
}
}
The Order attribute determines when the classification will be applied compared to other classifications which may also apply to a span of text.
The DisplayName will be used in the Tools > Options... dialog.
Once the classification is defined, an ITagger class can search a view's text and provide classifications for applicable sections of the text it finds.
Simply put, its job is to listen for the ViewLayoutChanged event of the text view, which is fired when the provided text view's content changes (e.g. because the the user has typed something).
It must then search the text for the area of text it is interested in (called a 'span'). Here, it returns spans of lines containing either #region or #endregion. I've kept this simple, but the TextSearchService used to find matches can also search using regular expressions.
Finally, a method is provided for Visual Studio to retrieve the tags of the text it has found, called GetTags(). For a given span collection, this will return text spans with classification tags, i.e. areas of those spans which should be classified in a certain way.
Its code is:
public sealed class RegionTagger : ITagger<ClassificationTag>
{
private readonly ITextView m_View;
private readonly ITextSearchService m_SearchService;
private readonly IClassificationType m_Type;
private NormalizedSnapshotSpanCollection m_CurrentSpans;
public event EventHandler<SnapshotSpanEventArgs> TagsChanged = delegate { };
public RegionTagger(ITextView view, ITextSearchService searchService, IClassificationType type)
{
m_View = view;
m_SearchService = searchService;
m_Type = type;
m_CurrentSpans = GetWordSpans(m_View.TextSnapshot);
m_View.GotAggregateFocus += SetupSelectionChangedListener;
}
private void SetupSelectionChangedListener(object sender, EventArgs e)
{
if (m_View != null)
{
m_View.LayoutChanged += ViewLayoutChanged;
m_View.GotAggregateFocus -= SetupSelectionChangedListener;
}
}
private void ViewLayoutChanged(object sender, TextViewLayoutChangedEventArgs e)
{
if (e.OldSnapshot != e.NewSnapshot)
{
m_CurrentSpans = GetWordSpans(e.NewSnapshot);
TagsChanged(this, new SnapshotSpanEventArgs(new SnapshotSpan(e.NewSnapshot, 0, e.NewSnapshot.Length)));
}
}
private NormalizedSnapshotSpanCollection GetWordSpans(ITextSnapshot snapshot)
{
var wordSpans = new List<SnapshotSpan>();
wordSpans.AddRange(FindAll(#"#region", snapshot).Select(regionLine => regionLine.Start.GetContainingLine().Extent));
wordSpans.AddRange(FindAll(#"#endregion", snapshot).Select(regionLine => regionLine.Start.GetContainingLine().Extent));
return new NormalizedSnapshotSpanCollection(wordSpans);
}
private IEnumerable<SnapshotSpan> FindAll(String searchPattern, ITextSnapshot textSnapshot)
{
if (textSnapshot == null)
return null;
return m_SearchService.FindAll(
new FindData(searchPattern, textSnapshot) {
FindOptions = FindOptions.WholeWord | FindOptions.MatchCase
});
}
public IEnumerable<ITagSpan<ClassificationTag>> GetTags(NormalizedSnapshotSpanCollection spans)
{
if (spans == null || spans.Count == 0 || m_CurrentSpans.Count == 0)
yield break;
ITextSnapshot snapshot = m_CurrentSpans[0].Snapshot;
spans = new NormalizedSnapshotSpanCollection(spans.Select(s => s.TranslateTo(snapshot, SpanTrackingMode.EdgeExclusive)));
foreach (var span in NormalizedSnapshotSpanCollection.Intersection(m_CurrentSpans, spans))
{
yield return new TagSpan<ClassificationTag>(span, new ClassificationTag(m_Type));
}
}
}
For brevity I have omitted namespaces and the using statements, which are typically of the form Microsoft.VisualStudio.Text.*. For these to be available, the Visual Studio 2010 SDK must first be downloaded.
I've been using this solution for the past few months without issue.
One limitation I noticed is colours are not 'blended', so a color with less than 100% opacity will not 'fade out' the existing colours in a span - which might be useful to preserve syntax highlighting.
I also have little idea of its efficiency, as it looks like it will repeatedly search a document on each keypress. I have not done the research to see if Visual Studio optimises this somehow. I do notice a slowdown of Visual Studio on large files (> ~1000 lines), but I also use Resharper, so I cannot attribute this to this plugin alone.
As this was coded mostly using guesswork, I welcome any comments or code changes which could clarify or simplify things or improve upon the code's performance.

I guess you could start with Visual Studio Add-in project, it will used EnvDTE, which was considered as Visual Studio Object Model, and please find MSDN document here:
http://msdn.microsoft.com/en-us/vstudio/bb968855
You could control your visual studio behavior, like debugger, code editor and so on by EnvDTE.

Correct way to implement web part personalisation for listboxes

Trying to work out this whole web part personalisation, and trying to implement it for a list box.
Well the end result will be two list boxes, with interchangeable values (ie, a value will only exist in one of the listboxes)
But I can't maintain the datasource for it. So maybe I'm going about it wrong?
This is what I have for a test H2 tag on the page
[Personalizable(PersonalizationScope.User)]
public string LabelText {
get { return h2Test.InnerText; }
set { h2Test.InnerText = value; }
}
And it works fine, if I have a textbox and use it to change the value of LabelText, then when I close the browser it automagically persists the change.
So I thought, ok, then maybe the same will work with a list box
[Personalizable(PersonalizationScope.User)]
public DomainList Domains {
get { return (DomainList)lstBxDomains.DataSource; }
set {
lstBxDomains.DataSource = value;
lstBxDomains.DataBind();
}
}
Where DomainList is just a class which extends List, and Domain is just a three field class, int, string, string.
But it doesn't, so is this too complicated for the webpart personalisation automagican, or have i just implement it wrongly (Which is more than likely)
This is my event handler to remove the items from the list:
protected void btnRemDomain_Click(object sender, EventArgs e) {
if (IsPostBack && lstBxDomains.SelectedIndex > -1) {
for (int i = 0; i < lstBxDomains.Items.Count; i++) {
if (lstBxDomains.Items[i].Selected) {
Domains.Remove(Domains.Find(d => d.ID.ToString() == lstBxDomains.Items[i].Value));
}
}
Domains = Domains;
}
}
The Domains=Domains; line is in there to see if explicitly setting the value made a difference (as Removing doesn't acutally reset the value of the field), but it doesn't. I've also tried creating a new local DomainList setting it to the global one, and then doing the remove/find on it, and then setting the local one to the global. But not working either.

I have managed to resolve this by using WebPart.SetPersonalizationDirty(this); in the set accessor of Domains, but would someone mind confirming if this is an appropriate way to do it?

Prism for Silverlight: How to maintain views in a specific order inside a region

I am creating sort of a "Navigation panel" (which is actually an ItemControl) for SL and using Regions to allow each module to add his link to the panel.
Problem is that modules loading is inconsistent and thus order of links in the panel can change according to modules loading order.
Restricting the modules order is out of the question.
Other feasible option is the order the region's Views Collection that is binded to the ItemControl, the problem is that ViewCollection is very limited, so ordering it is pretty hard.
Did I miss an option, do you have an idea?
Thanks
Ariel

In Prism4 you just apply the ViewSortHintAttribute to your views:
[ViewSortHint("100")]
class FirstView : UserControl { }
[ViewSortHint("200")]
class SecondView : UserControl { }
The default sort comparer on the regions will pick up this attribute and sort the views accordingly. You can put any string into the attribute but I tend to use medium sized numbers that allow me to easily put a new view in between existing ones.

Refering to Sam's answer you first have to build your comparer. The following one is also capable of views that do not have a dedicated wish to be positioned at. To attach this comparer to the region that has to be sorted you can use a way intruduced by the prism manual:
public partial class MainView : UserControl
{
public MainView( )
{
InitializeComponent( );
ObservableObject<IRegion> observableRegion = RegionManager.GetObservableRegion( ContentHost );
observableRegion.PropertyChanged += ( sender, args ) =>
{
IRegion region = ( (ObservableObject<IRegion>)sender ).Value;
region.SortComparison = CompareViews;
};
}
private static int CompareViews( object x, object y )
{
IPositionView positionX = x as IPositionView;
IPositionView positionY = y as IPositionView;
if ( positionX != null && positionY != null )
{
//Position is a freely choosable integer
return Comparer<int>.Default.Compare( positionX.Position, positionY.Position );
}
else if ( positionX != null )
{
//x is a PositionView, so we favour it here
return -1;
}
else if ( positionY != null )
{
//y is a PositionView, so we favour it here
return 1;
}
else
{
//both are no PositionViews, so we use string comparison here
return String.Compare( x.ToString( ), y.ToString( ) );
}
}
}

At least in prism V4 there you can tell the region manager how to sort the views in a specific region. You just need to provide a compare function to the region.
This example sorts by a very stupid value, the function name:
private static int CompareViews(object x, object y)
{
return String.Compare(x.ToString(), y.ToString());
}
this._regionManager.Regions["MyRegion"].SortComparison = CompareViews;
Of course the region needs to be known to the region manager before you can set the SortComparison. So far the only workaround I found to achieve this was to defer to set the comparison function using the Dispatcher:
private readonly IRegionManager _regionManager;
[ImportingConstructor]
public ShellViewModel(IRegionManager regionManager)
{
this._regionManager = regionManager;
Dispatcher dp = Dispatcher.CurrentDispatcher;
dp.BeginInvoke(DispatcherPriority.ApplicationIdle, new ThreadStart(delegate
{
if (this._regionManager.Regions.ContainsRegionWithName("MyRegion"))
this._regionManager.Regions["MyRegion"].SortComparison = CompareViews;
}));
}
Of course you should use some more useful information than the class name for the sorting order, but this should be easy to solve.

This is not built into Prism regions, however it's easily implementable.
Damian Schenkelman has posted an extension method he created for adding a region to an index that seems to work pretty well.
http://blogs.southworks.net/dschenkelman/2009/03/14/how-to-add-a-view-to-a-region-in-a-particular-index-with-prism-v2/
Hope this helps.

I found that Sam's solution worked, but discovered that it executes the sort when all views have been added to the region, thus sorting the views twice.
Although it is still a valid solution, reading this post in Prism discussion made me think about a way of implementing this just when the region has been loaded, but before any views have been added yet.
1 - Subscribe to the CollectionChanged of Regions collection
I placed this in the Shell ViewModel code which is the one associated to the View that contains the region I want to sort. Whenever the IRegionManager import has been resolved I subscribe to the CollectionChanged event of its Regions collection:
this._regionManager.Regions.CollectionChanged +=
new NotifyCollectionChangedEventHandler(Regions_CollectionChanged);
2 - Change the SortComparison of the region in the event delegate
Then the delegate Regions_CollectionChanged will execute whenever the Regions collection is updated and will change the SortComparison of my desired region:
void Regions_CollectionChanged(object sender, NotifyCollectionChangedEventArgs e)
{
if (e.Action == NotifyCollectionChangedAction.Add)
{
foreach (var o in e.NewItems)
{
IRegion region = o as IRegion;
if (region != null && region.Name == RegionNames.NavigationRegion)
{
region.SortComparison = CompareNavigatorViews;
}
}
}
}
3 - Define the CompareNavigatorViews delegate
In my case, I just sort the views by the title of the assembly where they are contained, you can implement your own compare method here. Remember that the objects you'll receive here are the Views and not the ViewModels.
private static int CompareNavigatorViews(object x, object y)
{
if (x == null)
if (y == null)
return 0;
else
return -1;
else
if (y == null)
return 1;
else
{
AssemblyInfo xAssemblyInfo = new AssemblyInfo(Assembly.GetAssembly(x.GetType()));
AssemblyInfo yAssemblyInfo = new AssemblyInfo(Assembly.GetAssembly(y.GetType()));
return String.Compare(xAssemblyInfo.Title, yAssemblyInfo.Title);
}
}
Just in case somebody asks, the AssemblyInfo class is an utility class I made. To get the title of an assembly you could use this function:
string GetAssemblyTitle(Assembly assembly)
{
object[] attributes = assembly.GetCustomAttributes(typeof(AssemblyTitleAttribute), false);
if (attributes.Length == 1)
{
return (attributes[0] as AssemblyTitleAttribute).Title;
}
else
{
// Return the assembly name if there is no title
return this.GetType().Assembly.GetName().Name;
}
}
Hope this helps someone!

Well as the lack of answers counting. I have not found a solution with Prism.
Instead I've used MEF to solve this.
I will write a blog post on it and update this place holder.