Pressing `shift-left/right` will exit multi-caret mode

[imkzh]

When multiple carets are inserted, no matter with or without selections, pressing shift-left or shift-right exits the multi-caret mode (in some cases), and selecting texts only under the first caret, instead of initiate(or adjust) text selections for every caret.

Scenario:

• If entered multi-caret mode with shift+up/down, then text selection works fine.
  • If carets are moved in any direction after (this would deselect texts under all carets, but keep all the carets in place, if any text previously selected), then selection failed to initiate/being adjusted correctly.
• If multiple carets are inserted by mouse clicking (holding alt) or column selection mode, selection failed to initiate correctly.
• shift-end/home works fine in both situation, but after that, pressing shift-left/right exits the multi-caret mode, and deselects texts under all other carets.
• will exit multiple selection mode initiated by ctrl-d(named "Add selection to next find match"), too.

As i remembered, there was a time when i could adjust multiple text selections simultaneously/synchronized. (confirmed: that is PyCharm instead of vscode)

It seems adjusting multiple selection will only work when all carets are "aligned" and "not modified yet", at present. Would this be a bug?

Also: move lines up and down does not work under multi-caret mode either, but this seems unrelated to this issue (i'm too lazy to submit this in a new issue).

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Tested: behaves exactly the same when all extensions are disabled.

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Version: 1.51.1 Commit: e5a624b788d92b8d34d1392e4c4d9789406efe8f Date: 2020-11-10T23:31:29.624Z (3 wks ago) Electron: 9.3.3 Chrome: 83.0.4103.122 Node.js: 12.14.1 V8: 8.3.110.13-electron.0 OS: Linux x64 4.15.0-23-generic (note: Ubuntu 16.04)

[alexdima]

Let's first try to find out what command executes on your machine, with your settings and your keybindings when pressing shift+right. Could you please try the following:

• Run the command Developer: Toggle Keyboard Shortcuts Troubleshooting
• This will activate logging of dispatched keyboard shortcuts and will open an output panel with the corresponding log file.
• Press exactly the keybinding you desire (shift+right)
• check what VS Code detects and what command is invoked.

If you are having trouble understanding the output, please feel free to paste here and I can try to help.

[imkzh]

Here is the output from keyboard shortcuts troubleshooting console: (manually formatted) it seems the problem is related to Column Selection Mode (i turned it on because i was working on some text based table from terminal output). @alexdima

# scope: column selection mode enabled:

    # action: holding alt and click to insert some carets:
    [2020-12-08 16:44:29.395] [renderer1] [info] [KeybindingService]: / Received  keydown event - modifiers: [alt], code: AltLeft, keyCode: 18, key: Alt
    [2020-12-08 16:44:29.395] [renderer1] [info] [KeybindingService]: | Converted keydown event - modifiers: [alt], code: AltLeft, keyCode: 6 ('Alt')
    [2020-12-08 16:44:29.396] [renderer1] [info] [KeybindingService]: \ Keyboard event cannot be dispatched.

    # action: press shift+right
    [2020-12-08 16:44:41.331] [renderer1] [info] [KeybindingService]: / Received  keydown event - modifiers: [shift], code: ShiftLeft, keyCode: 16, key: Shift
    [2020-12-08 16:44:41.331] [renderer1] [info] [KeybindingService]: | Converted keydown event - modifiers: [shift], code: ShiftLeft, keyCode: 4 ('Shift')
    [2020-12-08 16:44:41.331] [renderer1] [info] [KeybindingService]: \ Keyboard event cannot be dispatched.
    [2020-12-08 16:44:41.555] [renderer1] [info] [KeybindingService]: / Received  keydown event - modifiers: [shift], code: ArrowRight, keyCode: 39, key: ArrowRight
    [2020-12-08 16:44:41.555] [renderer1] [info] [KeybindingService]: | Converted keydown event - modifiers: [shift], code: ArrowRight, keyCode: 17 ('RightArrow')
    [2020-12-08 16:44:41.555] [renderer1] [info] [KeybindingService]: | Resolving shift+[ArrowRight]
    [2020-12-08 16:44:41.555] [renderer1] [info] [KeybindingService]: \ From 2 keybinding entries, matched cursorColumnSelectRight, when: editorColumnSelection && textInputFocus, source: built-in.

# scope: column selection mode disabled:
#    (in this scope, adjusting/initiating selection works fine)

    # action: hold alt and click to insert some carets:
    [2020-12-08 16:46:31.764] [renderer1] [info] [KeybindingService]: / Received  keydown event - modifiers: [alt], code: AltLeft, keyCode: 18, key: Alt
    [2020-12-08 16:46:31.765] [renderer1] [info] [KeybindingService]: | Converted keydown event - modifiers: [alt], code: AltLeft, keyCode: 6 ('Alt')
    [2020-12-08 16:46:31.765] [renderer1] [info] [KeybindingService]: \ Keyboard event cannot be dispatched.

    # action: press shift+right
    [2020-12-08 16:46:40.241] [renderer1] [info] [KeybindingService]: / Received  keydown event - modifiers: [shift], code: ShiftLeft, keyCode: 16, key: Shift
    [2020-12-08 16:46:40.241] [renderer1] [info] [KeybindingService]: | Converted keydown event - modifiers: [shift], code: ShiftLeft, keyCode: 4 ('Shift')
    [2020-12-08 16:46:40.241] [renderer1] [info] [KeybindingService]: \ Keyboard event cannot be dispatched.
    [2020-12-08 16:46:40.469] [renderer1] [info] [KeybindingService]: / Received  keydown event - modifiers: [shift], code: ArrowRight, keyCode: 39, key: ArrowRight
    [2020-12-08 16:46:40.469] [renderer1] [info] [KeybindingService]: | Converted keydown event - modifiers: [shift], code: ArrowRight, keyCode: 17 ('RightArrow')
    [2020-12-08 16:46:40.470] [renderer1] [info] [KeybindingService]: | Resolving shift+[ArrowRight]
    [2020-12-08 16:46:40.470] [renderer1] [info] [KeybindingService]: \ From 2 keybinding entries, matched cursorRightSelect, when: textInputFocus, source: built-in.

[alexdima]

@imkzh Thank you for the extra information. This works as expected, when in column selection mode, the multiple cursors will always try to become aligned by columns (like a box).

By the way, the Selection > Column Selection Mode toggle is just one of multiple ways to create column selection. You can also:

• use the middle mouse button
• configure "editor.multiCursorModifier": "ctrlCmd" and then do regular mouse selection and press alt to have it become a column selection
• configure keybindings for cursorColumnSelectDown, cursorColumnSelectLeft, cursorColumnSelectRight or cursorColumnSelectUp

[imkzh]

@alexdima thank you for the alt-key modifier solution.

But I still think there would be a bug. The carets can stay aligned or become unaligned after moving, even with carets still aligned, i could not initiate selection with keyboard.

Maybe we can make the program to check if the carets are still aligned before exiting the multi caret mode.

In column selection mode, make the following selection: contents in [] are selected, and a | denotes a caret.

L[or]|em ipsum dolor sit amet,
b[la]|h blah blah blah
f[oo]| bar

moving carets left will cancel the selection, but they are still aligned:

L|orem ipsum dolor sit amet,
b|lah blah blah blah
f|oo bar

and shift+right to initiate a new selection: what i expected:

L[o]|rem ipsum dolor sit amet,
b[l]|ah blah blah blah
f[o]|o bar

what i got:

L[o]|rem ipsum dolor sit amet,
blah blah blah blah
foo bar

[alexdima]

@imkzh How did you create the initial state?

L[or]|em ipsum dolor sit amet,
b[la]|h blah blah blah
f[oo]| bar

[imkzh]

@alexdima under column selection mode, click down after L on the first line and drag to select second o on the third line.

[hediet]

Still reproducable:

Seems like in column-selection mode, shift+left/right does not work for multi-cursors.

[hediet]

@alexdima What is the difference between CursorColumnSelectLeft and CursorLeftSelect? ColumnSelectCommand does not seem to be multi-cursor ready (it only uses primary cursor).

[alexdima]

CursorLeftSelect is the regular shift+left that can result that multiple cursors become "unaligned" e.g.

CursorColumnSelectLeft is only bound by default on Windows I believe and makes sure the result is a "column" selection (i.e. box selection). It also does not loop back to the end of the previous line, etc.