Review and unify the readonly and locked state of views

[mkommend]

Adjusted the SetEnabledStateOfControls method in all views, added the Enabled property into the IView interface and adapted the ViewHost, View and ContentView class with r4435.

[mkommend]

Changed the behavior and states of views. As this a major change in the MainForm class, the changes must be exhaustively tested.

[swagner]

Reviewed changes and encountered following issues:

• Saving the clipboard is allowed, even if it contains a running algorithm. After the save operation is completed, the algorithm view is not enabled anymore.
• Dropping values on a VariableValueView does not work anymore. However, the two methods valuePanel_DragEnterOver and valuePanel_DragDrop are still there.
• If the content of a content view is null, the whole content view is disabled (see ContentView, line 112). I think this is a bit too much. Each content view should decide on its own which controls should be enabled or disabled, if there is no content (for example, even if the content is null, a user should be able to switch tabs).
• View implements the Enabled property of IView explicitly. The code for suspending and resuming repaints is now located in this property. In the former solution View implemented the Enabled property using the new keyword. I think using the new keyword was the better solution. Now repaints will be suspended and resumed only if the Enabled property is set via the IView interface.
• In the ViewHost the space between the viewsLabel and the content should be increased by a few pixels.
• I think in line 170 of the OperatorGraphView (operator graph visualization) !Locked is not necessary.

[mkommend]

Registered drag events to enable drag and drop on VariableValueViews with r4445.

[mkommend]

Removed the coupling of the Enabled property with Content != null with r4446.

[mkommend]

Replying to swagner:

Reviewed changes and encountered following issues:

• Saving the clipboard is allowed, even if it contains a running algorithm. After the save operation is completed, the algorithm view is not enabled anymore.

Corrected saving of items in the Clipboard with r4447.

[mkommend]

Replying to swagner:

• I think in line 170 of the OperatorGraphView (operator graph visualization) !Locked is not necessary.

Enabled breakpoints in the OperatorGraphView although it is locked with r4448.

[mkommend]

Replying to swagner:

• View implements the Enabled property of IView explicitly. The code for suspending and resuming repaints is now located in this property. In the former solution View implemented the Enabled property using the new keyword. I think using the new keyword was the better solution. Now repaints will be suspended and resumed only if the Enabled property is set via the IView interface.

Refactored View.Enabled to hide the Control.Enabled property and additionally implement IView.Enabled explicitly with r4449.

[mkommend]

Refactored the Clipboard to handle IExecuteables and repositioned the label in the ViewHost with r4453.

[mkommend]

Forgot to update the caption of the ViewHost, when the active view is changed with r4465.

[swagner]

Reviewed changes and encountered following issues:

• The ViewHost in the VariableValueView is always disabled.
• Dropping values onto a VariableValueView does not work.
• I would recommend a slightly different message in the clipboard, when not all items can be saved (changed in r4500).

[mkommend]

Replying to swagner:

• The ViewHost in the VariableValueView is always disabled.

I could not verify that the ViewHost is always disabled.

• Dropping values onto a VariableValueView does not work.

Forgot to set AllowDrop to true for VariableValueView with r4509.

[mkommend]

SetEnabledStateOfControls must be called after the changes of ReadOnly and Locked have been propagated to nested views. Otherwise it is not possible to change the properties for a nested view.

[mkommend]

Called SetEnabledStateOfControls after the state changes have been propagated with r4519.

[mkommend]

Enabled dropping of values on various views with r4522.

[mkommend]

Corrected locked and readonly state in ExperimentView with r4526.