Can make both ways Alt + click and Alt+T or any other to select no issue.
I think its good feature to have some checkbox in interface or shortcut Alt + click to select whole folder on mouse click.
This way user open multiple folders at once and work not by selecting individual file, but rather selecting one file and it automatically selects folder with all files belonging to the folder.
Little background on why this is feature is desired by me. When i need to preform action on the whole album (in 90% of cases i use ID3tag to modify whole album, not individual files) drag and drop individual albums is extra work and selecting files from one album in the list requires focusing my mind - reading aiming mouse (to indecently not include file from next or previous album) which drains my mind of energy quick especially when i need to make routine procedure like getting tags from web, for 100+ albums.
I like that very much also. If all you need is double click "Path " column and it selects all files in that path. Even though it requires grabbing mouse, but also also takes out a lot of unnecessary brain work.
Perhaps can still allow to open mp3 file in player by double clicking "Filename" column.
All 3 methods of selection can use same exact code to execute, only difference is in the way that code gets path to the folder either by:
- select file then use keyboard shortcut
- double click path column
- hold Alt and select file