1818009 - Default width of 3pane is too narrow

Status: RESOLVED FIXED

(Thunderbird :: Mail Window Front End, defect)

Description

[Rob Lemley [:rjl]]

On a fresh profile, messenger.xhtml sets a default width of 1024px (or smaller if a narrow screen).
https://searchfox.org/comm-central/rev/7559777da5005a906731e9622f92569489e0862c/mail/base/content/messenger.js#194-209

Realistically, this is too small. On Windows, the Mail tab is usable unless the today pane is enabled, then the message list and display boxes are too small to be useful. The Calendar tab is worse, at 1024px wide the default week display (week being the default view) cuts off at either Thursday or Saturday depending if the Today Pane is visible. Month/Multiweek compress the day widths so the entire week is visible, but the display of the event itself cuts off at the start time, so you cannot see the description.

It looks like a width of 1329px is sufficient to display the Calendar in week view with the Today Pane and not cut off days.

We should have our own telemetry on this (maybe?) -- but even if not, the Firefox Public Data Report has useful information: 65% of screens use either 1920x1080 or 1366x768. Of the remaining 35%, 8% fall into an "Other" category that includes widths less than 1024px as well as above.

Using (older) data from https://firefoxgraphics.github.io/telemetry/#view=monitors, we can get more specific:

Width (as w)	Count	Increment %		Width (as w)	% Smaller
w <= 1024	26115	2.42%		w <= 1024	2.42%
1024 < w <= 1080	2927	0.27%		w <= 1080	2.69%
1080 < w <= 1152	1555	0.14%		w <= 1152	2.83%
1152 < w <= 1280	55556	5.14%		w <= 1280	7.97%
1280 < w <= 1366	257484	23.81%		w <= 1366	31.78%
1366 < w <= 1440	30296	2.80%		w <= 1440	34.58%
1440 < w <= 1600	73241	6.77%		w <= 1600	41.36%
1600 < w <= 1680	24683	2.28%		w <= 1680	43.64%
1680 < w <= 1920	545072	50.41%		w <= 1920	94.05%
1920 < w <= 2560	34529	3.19%		w <= 2560	97.24%
2560 < w <= 3840	28677	2.65%		w <= 3840	99.89%
3840 < w <= 11880	1161	0.11%		w <= 11880	100.00%

94% of Firefox Desktop users have screens <= 1920px wide. We should take advantage of this width by default and not make users adjust the window themselves. First impressions and all that good stuff.

Personally, the first thing I do after setting up an account on a new profile is adjust the window size so it's useful. I see this as an easy win.

In terms of CI testing, Windows tests run at 1280x1024, Linux at 1600x1200, and macOS at 1920x1080. I don't see anything specifically testing the width of messenger.xhtml. It should be added.

Comment 1

[Rob Lemley [:rjl]]

If the Today Pane is not active, a width of 1120px is sufficient to display the complete Calendar week.

Comment 2

[Rob Lemley [:rjl]]

Attachment: Bug 1818009 - Set more reasonable default window size. r=#thunderbird-front-end-reviewers

This is based on how Firefox sets the initial window size for a new profile.
A screen width of 1280 will drop to 1152, which is sufficient to display the
UI elements comfortably assuming the Today Pane is not active.

Comment 3

[Thomas D. (:thomas8)]

Thanks for improving this, Rob!

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/comm-central/rev/562ee9313670
Set more reasonable default window size. r=aleca