For the touchscreens also "Select multiple"-method to the main menu of Nautilus would be good. That would work as with Android-filemanagers, when you get a checkbox beside every icon/item, and one can left click and select multiple items randomly. But that kind of feature would need much more coding. Having "Add to selection" in to the context-menu is much less work to do, I'd assume.

Right now, I noticed, if one item is selected and top of an another item is context menu opened with left-click, the first selection is cleared.

Hello. Thanks for taking the time to write this bug report.

(In reply to comment #0)
> Only way to select multiple files and folders in Nautilus is by dragging a
> rubber band around them. If the file- and folder icons are not grouped GUIwise
> spatially together, it is impossible or too difficult to select multiple files
> with just a mouse.

This is true. Rubber band is not very useful when the items cannot be spatially rearranged by hand. I'd also add that rubber band selection doesn't even work on List view.

> Overall, ALL main methods in ALL GUIs of ANY program should be doable just only
> with mouse and just only with keyboard, without needing necessary both.
> 
> I wish this would become some guideline to GNOME, so applications would also be
> tested if their main functions works just by using mouse/keyboard.

I feel that this is generally agreed with.

There are some draft guidelines in the making about this:
- "Ensure that all the functionality provided by your application can be accessed using a keyboard, including toolbars, links and buttons. Trying to use your application only with a keyboard is a great way to test this." https://wiki.gnome.org/Design/HIG/KeyboardInput
- "always make sure that actions can be found elsewhere, such as through selection mode" https://wiki.gnome.org/Design/HIG/PointerAndTouchInput

New applications, such as "gnome-documents" already allow arbitrary selections using only the mouse. And this is in the plans for nautilus as well. The main reason that this is not done yet is that it hasn't been done yet.
 
> (For touchscreens the above requirement is even more important but for desktop
> computers also there is many situations when only mouse or only keyboard is in
> use or is practical to use.)

True.
 
> About Nautilus considering above: 
> 
> 1)
> In Nautilus, to the context menu (2nd mouse button) "Add to Selection"-method.
> The same behaviour when one selects by left-clicking and holding Ctrl on
> keyboar.
> With that a user can select multiple files randomly in the Nautilus window and
> finally do some operation on them.

That's an option. One problem is that it relies on context menus, which are not discoverable, and don't work well on touch. Another problem is that this is not the pattern used in other GNOME Applications.

That pattern, which is known as "selection mode", is already implemented in gnome-documents. It allows various selection methods (text selection-like rubberband, ctrl/shift + click, right click to start selection, selection mode button on the header bar, left click adds to selection...).

> 2)
> Also, when multiple items are selected, it should be possible to feed the
> filenames as an argument list to the program. 
> For example, if I now select multiple files and then choose "Open with..." from
> the context menu, and from there I select a program /usr/bin/xmessage, I would
> expect all the selected file names be visible in the xmessage window, but
> nowadays just the first filename is showing.
> 
> I assume, there is (maybe) some method how scripts can get all selected items
> from Nautilus, but that method is generally poorly supported. Maybe some
> wrapper script could be written to the middle (or already is?) to retrieve
> selected items and output them as CLI argument-strings. 
> 
> An example: I select multiple video files randomly in Nautilus and then select
> from the context menu: "Open selected as CLI args with" -> xmessage, and would
> see the path+filenames of all selected items.

This is not very related to selecting files with mouse. You can file it as a separate enhancement report. However, please note that not all programs accept multiple files as arguments in the same command, and nautilus doesn't guess whether they accept or not; it is the other application's responsibility to declare if they accept multiple files as arguments or not, according to the XDG desktop file specification: http://standards.freedesktop.org/desktop-entry-spec/latest/ar01s06.html

(In reply to comment #1)
> For the touchscreens also "Select multiple"-method to the main menu of Nautilus
> would be good. That would work as with Android-filemanagers, when you get a
> checkbox beside every icon/item, and one can left click and select multiple
> items randomly. But that kind of feature would need much more coding. Having
> "Add to selection" in to the context-menu is much less work to do, I'd assume.

Indeed, GNOME selection mode has a lot of similarities to Android's.

> Right now, I noticed, if one item is selected and top of an another item is
> context menu opened with left-click, the first selection is cleared.

Yes, this is currently true for nautilus. But for gnome-documents, which has implemented the selection-mode pattern, a right click on a second item doesn't clear the first selection. I'd expect selection mode in nautilus to work the same way.


All of this and related bugs are marked as duplicates of bug 138931, so I'm marking this one as well, so that we can track the work on selection mode in the same place. Please feel free to file any further enhancements or bugs you find.

*** This bug has been marked as a duplicate of bug 138931 ***