Issue 27606 - CTRL mouse wheel zoom does not behave logarithmically
Summary: CTRL mouse wheel zoom does not behave logarithmically
Alias: None
Product: Draw
Classification: Application
Component: ui (show other issues)
Version: OOo 1.1.1
Hardware: PC Windows XP
: P3 Trivial (vote)
Target Milestone: ---
Assignee: AOO issues mailing list
QA Contact:
Depends on:
Reported: 2004-04-08 12:45 UTC by jonaswidarsson
Modified: 2013-02-07 22:35 UTC (History)
1 user (show)

See Also:
Latest Confirmation in: ---
Developer Difficulty: ---


Note You need to log in before you can comment on or make changes to this issue.
Description jonaswidarsson 2004-04-08 12:45:42 UTC
A mathematic bug on "CTRL + Mouse scroll whell zooming" (CMSWZ) behaviour.
This is really about enhancing, but I chose the issue type: DEFECT, since it is
a bit annoying.

I can confirm this for all OOo applications as well, but the report applies best
for the drawing application.

* CMSWZ centers on the view and changes zoom value for every scroll wheel
"snap". It does not take care of the cursor's position when scrolling. It just
zooms into/out from the current visible rectangle.

* The CMSWZ increment rate is adding/subtracting 10 percents to the scroll value
for every snap, rather than multiplying/dividing with a pleasant factor (maybe
1.1) for every snap. This makes the CMSWZ experience completely useless when
operating on high zoom percent values. 1010% zoom factor does not differ very
much from 1020%...

Take a look at this electronic cad program:
More specifically:
(The program is Eagle 4.11. Click on the blue large download icon at the top to
fetch an exe-file.)

If you don't wan't to, I'll try to explain here:

It has a MSWZ functionality that (at least to some extent) centers the zoom
action on the mouse position.

If you see the whole page and want to zoom a particular spot, just move your
mouse pointer there and ctrl+scroll wheel up.

If you are zoomed in on the left part of a page, and want to view it all, you
would place the mouse pointer to the left on the screen and (press ctrl) scroll
down. The zoom action centers on the mouse position and therefore, the whole
page becomes visible. If you had had the pointer to the right and zoomed out,
you'd have the view showing more and more of the area off the WYSIWYG document.
If you don't get what I mean, download the program above and you'll see. It is

This functionality often reduces use of scrollbars or panning, since it is so
effective when going from one small detail on the page to another.
Added that the CMSWZ had a logarithmic zoom behaviour, CMSWZ would be the zoom
god. Of course, noone should remove the need to press the CTRL-key for mouse
wheel zooming. That is a good and needed feature.

Since CMSWZ is already implemented, I think a quick hack would be enough for
fixing this. Just change the math to multiplication/division of a factor, and
take into account where the mouse is, and you're done.
If you guys agree that this is something that needs to be done, it is really a
lightweight job to add the feature, but it would spare tons of time for the end
Comment 1 wolframgarten 2004-04-08 13:01:12 UTC
Thanks for your help. But nevertheless this is not a bug. Change it to enhancement.
Reassigned to Bettina.
Comment 2 jonaswidarsson 2004-04-08 13:30:23 UTC
It came to my mind that the panning (taking the mouse position into account when
zooming) part of this suggestion maybe should be optional, and the setting
accessible in the 

I can imagine a dear friend of mine swearing because this person don't
understand that the mouse position matters...
Comment 3 danzoid 2007-08-20 12:37:25 UTC
This is still an issue for OOo v 2.2.1,

jonas is correct, we long time CAD gurus are VERY used to zooming in/out with 
mousewheel centered on cursor, and also the log scale makes very good sense.

AutoCAD has always acted as jonas described. (and likely the many acad clones 
out there.)
Comment 4 bettina.haberer 2010-05-21 14:59:16 UTC
To grep the issues easier via "requirements" I put the issues currently lying on
my owner to the owner "requirements".