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Before this implementation, specific status via former mergeOverlayIcon() was greyed out
with the visibility.
With this commit, the developer has two options:
a) override mergeGreyableOverlayIcons, in which case the overlay will
be greyed out when the item is greyed out as per former mergeOverlayIcon()
b) override mergeColorfulOverlayIcons, in which case the overlay will
be superimposed after the icon is greyed out as it is the case for stardard
error and recompute flags.
A better fix for #0004188
Delay calling setPreviewDisplayMode() in ViewProviderPrimitive::setEdit
also fixed issue of not turning off preview mode if the user cancels
editing because there is already a task dialog active.
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fixes#4241
Problem:
PartDesignGui::ViewProvider is responsible for closing the tasks for most of PD features when exiting edit mode
(i.e. unsetEdit()).
For primitives, PartDesignGui::ViewProviderPrimitive is responsible, and neither does it or relies on its parent
VP to do it when calling unsetEdit().
Solution:
Make PartDesignGui::ViewProviderPrimitive::unsetEdit() rely on parent PartDesignGui::ViewProvider to tidy up,
including closing the task dialog.
Reference:
This is the default stack call when closing a document while a PD task using PartDesignGui::Viewprovider is active:
With the recently introduced AttachExtension the PartDesign primitives can be attachable by themself and don't need anymore the helping coordinate system datum. This simplyfies the code and the TreeView largely
