923510 - Events are sent to page when invoking switch tab keyboard shortcuts (cmd-opt-left/right)

Status: NEW

(Firefox :: Keyboard Navigation, defect)

Description

[Elliott Slaughter]

When pressing cmd-opt-left/right to switch tabs on Mac OS X, I have noticed that the page in foreground before the tab switch receives some sort of event which causes a state change in the page. This can be reproduced on several websites including Pandora and Google Docs.

For Pandora:
1. Open a new Firefox window with three tabs in this order:
1.a. http://google.com (on the left)
1.b. http://pandora.com (in the center)
1.c. http://google.com (on the right)
2. In Pandora, skip two songs (press the >>| button twice) so that the song queue has a couple songs in it.
3. Notice that in the Pandora song queue, the last (rightmost) song is initially selected.
4. Click (don't use keyboard shortcuts) on the rightmost tab (Google).
5. Press cmd-opt-left twice to switch to the leftmost tab, passing over Pandora.
6. Click (don't use keyboard shortcuts) on the center tab (Pandora).
7. Notice that Pandora song queue has shifted back to the first song you played. (This is equivalent to if you had pressed the left arrow key twice while focused on the Pandora tab.)
8. Click (don't use keyboard shortcuts) on the leftmost tab (Google).
9. Press cmd-opt-right twice to switch to the rightmost tab, passing over Pandora.
10. Click (don't use keyboard shortcuts) on the center tab (Pandora).
11. Notice that Pandora song queue has shifted back to the last song you played. (This is equivalent to if you had pressed the right arrow key twice while focused on the Pandora tab.)

For Google Docs:
1. Open a new Firefox window with three tabs in this order:
1.a. http://google.com (on the left)
1.b. http://docs.google.com (in the center)
1.c. http://google.com (on the right)
2. In Google Docs, create a new spreadsheet. Make sure the spreadsheet is the center tab and close the Google Docs home page.
3. Notice that the cursor is initially highlighted over the leftmost column in the spreadsheet (column A).
4. Click (don't use keyboard shortcuts) on the leftmost tab (Google Search).
5. Press cmd-opt-left twice to switch to the rightmost tab, passing over Google Docs.
6. Click (don't use keyboard shortcuts) on the center tab (Google Docs).
7. Notice that cursor has moved to the rightmost column in the spreadsheet (column T with default settings).
8. Click (don't use keyboard shortcuts) on the rightmost tab (Google Search).
9. Press cmd-opt-right twice to switch to the leftmost tab, passing over Google Docs.
10. Click (don't use keyboard shortcuts) on the center tab (Google Docs).
11. Notice that cursor has moved to the leftmost column in the spreadsheet (column A).

Clearly these pages are receiving some sort of event when the user scrolls past them using keyboard shortcuts. I am not sure whether the key event is being leaked or not (because e.g. the movement of the cursor across a spreadsheet in Google Docs skips more than one column); it could potentially be an unwanted scroll event.

Comment 1

[David Balažic]

Not sure if the same, but:

FF 38.0.5 on Windows 7

Keyboard events are sent to the page that clearly should not (IE and Chrome don't do it). Example:
 - open http://dmauro.github.io/Keypress/ (a handy page showing events that it receives)
 - open the FF about dialog
 - dismiss it with the ESC key

Result: the page "sees" the ESC being pressed when clearly it was not intended to be sent to the page, but to dismiss the dialog (which is unrelated to the page content)

 - on the same page, open the context menu on the page
 - with keyboard, select an item (like "View Page Source") usign the cursor up/down keys, then press ENTER

Result: the page "sees" the ENTER key event (code 13).

And quite some other examples.


The practical result is, that using the Firefox GUI triggers actions in javascript pages that were clearly not intended.

Comment 2

[Andrew Veritas]

I hit the same problem, but when switching between tabs with the alt-# shortcuts: this also passes the keypress to the enclosing tab. Firefox should consume keypresses it acts on, and not pass them to the tab's web page.

Steps to reproduce:
1) Open Google Calendar as first tab (new version as of roughly December 2017, which accepts 1-6 keys as shortcuts. Keyboard shortcuts enabled - this is the default.)
2) Open at least two other tabs
3) Switch to Google Calendar tab
4) Use alt-2 to switch away from Calendar
5) Switch back to Calendar
6) Use alt-3 to switch away from Calendar
7) Switch back to Calendar
8) goto 4

Expected result:
at (5) and (7), Calendar shows the same view. (I.e. Calendar receives no keyboard input from Firefox).

Actual result:
at (5) and (7), Calendar shows different layouts. This is because Calendar has processed the alt-2 and alt-3 as "2" and "3" respectively.


Firefox 52.5.0 (64-bit) on Debian buster/sid, Gnome 3.22.2