Provide ability to reuse views if the content is already displayed

[mkommend]

The mainform should provide a method overload of ShowContent which specifies if an existing view displaying the same content should be reused.

[mkommend]

Implemented ShowContent method in MainForm which reuses existing views and adapted the ClipBoard with r5270.

[mkommend]

Corrected check in setter of ViewType in the ViewHost with r5278.

[abeham]

I reviewed r5270.

I made some attempts in thinking about a ShowContent<T, U> where T : class,IContent where U : class,IContentView. However that's not so easy in the case no existing view can be found. Since U can be an interface, one would be required to check for a view for the content's type which typeof(U) is also assignable from.

Anyway since the view is returned to the caller, the check can be made there if that was the required view.

I'm forwarding this to swagner for reviewing the change r5278 and the change to the Clipboard.

[swagner]

I think line 113 of ViewHost in r5278 should be

if (value != null && value == typeof(ViewHost))

and not

if (value != null && value.GetType() == typeof(ViewHost))

Apart from that I agree with the changes of r5270 and r5278. Thanks.

[mkommend]

Replying to swagner:

I think line 113 of ViewHost in r5278 should be

if (value != null && value == typeof(ViewHost))

and not

if (value != null && value.GetType() == typeof(ViewHost))

Apart from that I agree with the changes of r5270 and r5278. Thanks.

The check was corrected as suggested in r5318.