Drag and Drop Icon Management

[dszidi]

Allow users to add/remove icons via drag and drop.

[dszidi]

Planned Implementation Notes

Current implementation has an NSWindow created in controller and then DockIcon instances added as subviews to the window. This is an overly simplistic approach and will require an extra layer of abstraction to get the drag and drop functionality to work. Changing to the new hierarchy will also have other benefits later on.

New hierarchy should use a new base class DockGroup (inherits from NSView) for the icon groups. The DockGroup views get added to the NSWindow and serve specific functions.

NSWindow

• FileManagerIconView (DockGroup) Static single icon at the beginning of Dock
• DockedIconsView (DockGroup) Saved launchers
• UndockedIconsView (DockGroup) Running Apps
• PlacesView (DockGroup) User saved directory shortcuts
• TrashIconView (DockGroup) Static single icon at the end of Dock

DockGroup base class

Features

• Inherits from NSView
• implements drag/drop protocols NSView <NSDraggingSource, NSDraggingDestination>
• acceptedType property can be either an application or directory but not both
• acceptsIcons property
• canDragReorder property
• canDragRemove property
• canDragMove property
• screenEdge property (Bottom | Left | Right)
• Methods to arrange DockIcon entries
• Method to insert DockIcon at index

DockGroup Instances

First and last icons of the dock are actually in their own locked down groups and are hard coded to file manager first position and trash can in last position. Doing this will keep the logic of the DockGroup class simpler without logic to accommodate the edge cases.

FileManagerIconView

• acceptedType set to application
• acceptsIcons set to NO
• canDragReorder set to NO
• canDragRemove set to NO
• canDragMove set to NO
• screenEdge set by DockAppController

DockedIconsView

• acceptedType set to application
• acceptsIcons set to YES
• canDragReorder set to YES
• canDragRemove set to YES
• canDragMove set to YES
• screenEdge set by DockAppController

UndockedIconsView

• acceptedType set to application
• acceptsIcons set to NO
• canDragReorder set to NO
• canDragRemove set to NO
• canDragMove set to YES (so you can add it to DockedIconsView)
• screenEdge set by DockAppController

PlacesView

• acceptedType set to directory
• acceptsIcons set to YES
• canDragReorder property
• canDragRemove property
• canDragMove set to YES
• screenEdge set by DockAppController

TrashIconView

• acceptedType set to application
• acceptsIcons set to NO
• canDragReorder set to NO
• canDragRemove set to NO
• canDragMove set to NO
• screenEdge set by DockAppController

All of these DockGroups will be added to the NSWindow as subviews. DockIcon instances will be added to these DockGroups as subviews. This will leave us with a hierarchy that looks like this...

NSWindow -> DockGroup -> DockIcon

[dszidi]

Update:

It seems I completely missed NSDockTile. I have made a bunch of progress on this project already but will need to leverage NSDockTile as it provides much expected functionality. This is not only good for Gershwin development, but any porting of Mac apps to our GNUstep based environment will likely require NSDockTile to get all the dock related features of the application.

[dszidi]

It seems switching to using NSDockTile requires more refactoring than I would like for this issue. I will address it as a separate task.