Code review comment for lp:~unity-team/unity/unity.coverflow

When compiling this branch I get some errors about a missing LensDirectoryReader from test_filesystem_lenses.cpp in the test_gtest_dbus target.

When running the branch (by hacking CMakeLists.txt) - holy moly that is one responsive ui :-D maybe a tad too responsive as noted by John. But I feel like my laptop is turbo charged, so that's nice though :-)

Interaction wise it took me quite some time to grok how to scroll the flow (dragging only occured to me as an option after reading John's comments here). I think I was expecting it to scroll when the mouse neared the left/right edges of the row. This would also match the scrolling behaviour of the launcher.

I was also puzzled why the list was offset to the middle of the dash initially, so the leftmost 50% was empty.

Regarding John's comments about special behaviour in different lenses we need to put some hooks in libunity to let the lenses themselves control this and then update the lenses themselves to use these hooks. I am thinking two new renderer names "tile-flow" (which uses icon size similar to the current "tile-*" renderers) and a "cover-flow" renderer that uses bigger cover like icons.