Changes

Fix SWTException when closing source editor

When closing the editor which served as input provider for the property
view, an SWTException would occur when trying to access a disposed SWT
widget.

Change-Id: I657848446ef822211b531dd1b5f39012002b86dc
Signed-off-by: Pierre-Charles David <pierre-charles.david@obeo.fr>

[498748] Only invoke a text's callback when really needed

* Do not mark a text field as dirty when rendering the current model
  state. When setting up the text field's content to the current state
  of the model, we must call Text.setText(), which triggers the
  ModifyListeners. But in this context we don't want to mark the widget
  as dirty, otherwise leaving the page would trigger the associated
  edition tool (hopefully it would be a no-op if the tool is properly
  idempotent, but it's still bad for performance).

* Avoid calling the callback associated with the text widget on every
  focusLost is the text was not actually changed.

Bug: 498748
Change-Id: I9434e80b8a004e859b7373e728f9b69b4ca7dc86
Signed-off-by: Pierre-Charles David <pierre-charles.david@obeo.fr>

[502048] Return an explicit IStatus for model changes

Bug: 502048
Change-Id: I4c07d57dc826ab58b95b76fded8c6f2930c6368e
Signed-off-by: Pierre-Charles David <pierre-charles.david@obeo.fr>

[502048] Reset widgets' UI state on model change error

For all widgets whose visual state changes before we launch the
associated model change operation, make sure we revert to the previous
reference state if the operation failed.

Bug: 502048
Change-Id: I94a21cbbd1474451cd3af6ce47b701a0c06db781
Signed-off-by: Pierre-Charles David <pierre-charles.david@obeo.fr>