When scrolling the mouse wheel, zoom to the cursor

[GoogleCodeExporter]

Since 0.4, labyrinth has a much expected zooming feature. However, when you
scroll the wheel the zoom is centered on the center of the window. Other
apps zoom similarly, EOG being an example. But it zooms to the area where
the cursor is placed, which is much handier since it makes it easier to
focus on a specific item.

Please replicate this behaviour.

Original issue reported on code.google.com by frandavi...@gmail.com on 9 Apr 2008 at 8:27

[GoogleCodeExporter]

Original comment by matthias...@gmail.com on 9 Apr 2008 at 5:08

• Added labels: Type-Enhancement
• Removed labels: Type-Defect

[GoogleCodeExporter]

I added this behaviour but it feels really strange since the current location 
jumps
around very heavy. But maybe if enough users are convinced this can stay.

Original comment by matthias...@gmail.com on 13 Apr 2008 at 3:46

• Changed state: Started

[GoogleCodeExporter]

"since the current location jumps around very heavy"

Hmmm... it shouldn't, I'm not sure I'm following you. The idea is, if the 
cursor is
over a specific thought, to always zoom to / from it so theoretically nothing 
should
"jump around".

Original comment by frandavi...@gmail.com on 14 Apr 2008 at 6:40

[GoogleCodeExporter]

Yes, it does what you say. _But_ if the cursor stays at the same position, so 
if you
scroll the wheel two times (the wheel locks two times) you will end up too far 
ahead.
Otherwise you constantly need to move the cursor around to get to the desired 
position.

There are two solutions I can think of. First of all don't just move there and 
zoom
in, but do it smoothly with an animation. The second solution is to make the 
zoom
steps smaller.

Original comment by matthias...@gmail.com on 14 Apr 2008 at 10:44

[GoogleCodeExporter]

I have to admit I just got lost. The point of it is that, no matter how quickly 
you
zoom in, the cursor always stays over the same element.

Please take a look at how it works in EOG. open a random image, then pick a 
specific
point in it -someone's eye, a plate number, whatever-, place the cursor over it 
and
start zooming in and out. No matter how fast or suddenly you do it, the cursor
always, always stays over the chosen point in the image. No need to move it at 
all to
get to the desired position.

I haven't tried this new behaviour in Labyrith, but from your explanation I 
infer
that it does not work the same way.

Original comment by frandavi...@gmail.com on 14 Apr 2008 at 11:51

[GoogleCodeExporter]

You should've told me to ctrl-zoom, eog just switches to the next picture if
scrolling with the wheel. But no I got what you mean, however it isn't that 
easy to
implement.

Oh and what I was doing was centering the point you were pointing at and then 
zoom.

Original comment by matthias...@gmail.com on 14 Apr 2008 at 4:01

[GoogleCodeExporter]

This seems to work asymmetrically in trunk - when I scroll out, it goes from 
the centre of the window, but when I scroll in, it centres on my cursor. This 
is annoying because if I scroll out and back in without moving my mouse, the 
map goes off screen and I lose it. I've not yet found a way to centre the 
screen on the map.

It's also lacking any indication of how far in or out you're zoomed, or a way 
to return to 'normal' zoom.

Original comment by tak...@gmail.com on 6 Aug 2012 at 8:57