Changes to the hierarchical TrackScheme

[maarzt]

This PR changes the Hierarchical TrackScheme. The goal is to allow the users to get a better overview of the data. The rendering of the Hirarchical TrackScheme is changed slightly. And there are new menu items. That allow to only show a selected track or downward track in the Hierarchical TrackScheme.

This PR fixes https://github.com/mastodon-sc/mastodon/issues/172

Changes to the rendering of the Hierarchical TrackScheme:

• Use edges with corners, like in the branch graph TrackScheme.
• Wider lines.
• All nodes have the same size, which only depends on the zoom factor.
• Put the labels below the nodes.

Allow to zoom out further in the hierarchical TrackScheme:

Allow to show only a subset of the tracks in the hierarchical TrackScheme:

Refacoring of the LineageTreeLayout class

I had a deeper look into the LineageTreeLayout class in order to implement the new functionality. The code was quite complicated so a refactored a lot of stuff such that I could understand it better:

• Make LineageTreeLayout an interface an move the implementation to LineageTreeLayoutImp
• Replace the boolean paintLongEdges setting in TrackSchemeOptions by using a LineageTreeLayoutFactory.
• Simplify the quote "impenetrable" layoutX_iterative() method in LineageTreeLayout by using a new DepthFirstIteration class.
• Move code for managing a Table of TrackSchemeVertices from LineageTreeLayout to TrackSchemeVertexTable.
• Reduce the code in LineageTreeLayout and LongEdgesLineageTreeLayout by adding the new methods addScreenVertex and buildScreenColumns

New HierarchyLayout class I added a new HierarchyLayout class the only purpose is to hide the label of the root node. The label would otherwise be printed over an edge. And the label is anyway visible as the title of the column.

[maarzt]

Some thoughts:

• Should the list of root nodes to be shown, be held in the LongEdgesLineageTreeLayout?
• We can have the same "Show only selected tracks" functionality for the normal TrackScheme view. It would actually be pretty simple. We only need to move some code from MamutBranchViewTrackScheme to MamutViewTrackScheme and from LongEdgesLineageTreeLayout to LineageTreeLayoutImp.
• Is the HierarchyLayout really needed, or is there a better way to hide the label of the root node? The ScreenVertex unfortunately misses the information about the number of children, timepoint, etc...

[maarzt]

@tinevez Sorry, I could finish this today. And I won't have time to look at this before next week.

[maarzt]

Hi @tinevez, I will start now to fix the remaining issues.

[maarzt]

@tinevez Ok, I think it's ready now. Please review my last changes and merge it.

[maarzt]

:partying_face: