Opened 18 years ago

Closed 18 years ago

Last modified 15 years ago

#154 closed defect (fixed)

Zoom to selected does not work with POINT Layer

Reported by: horst.duester@… Owned by: g_j_m
Priority: major: does not work as expected Milestone:
Component: Data Provider Version: Trunk
Keywords: Cc:
Must Fix for Release: No Platform: RedHat
Platform Version: Awaiting user input: no

Description


Change History (8)

comment:1 by anonymous, 18 years ago

Owner: changed from gsherman to g_j_m

Works for me, except that selecting just one point and then zooming to selection results in a very zoomed out map.

comment:2 by g_j_m, 18 years ago

Zoom to selection for a single point now does something more sensible (SVN r5538). Not sure if this will fix this ticket. If not, can we have some more detail on how it doesn't work?

comment:3 by horst.duester@…, 18 years ago

Now it works but the selected point will be shown in a very very large scale. I think the best way to zoom to one selected point is to keep the actual scale of the view. So you can choice your prefered scale in case of one selected point. If you select more than one point QGIS have to decide whether or not to change the scale depending on the spatial distribution of the selected points.

comment:4 by g_j_m, 18 years ago

Sounds like a reasonable solution to let the user decide whether to zoom in to a very large scale or to zoom to a predefined scale for single points, although I'm not sure how easy it would be to do in qgis (the scale is sort of worked out as an afterthought).

comment:5 by g_j_m, 18 years ago

After some more thought, I think the problem (and solution) comes down to: what does the user expect when zooming into selected features?

For me, I expect the view to be zoomed so that the selected features fill the map. With a single point, this expectation can't hold in the same way that it does for features with some spatial extent.

I would be surprised (at qgis) if the zoom to a single selected point gave a view with lots of other, unselected, points. So my expectation is that the zoom should be sufficient so that only the selected point is visible, and the very large scale is just a minor side-effect of that.

Comments?

comment:6 by horst.duester@…, 18 years ago

I would be surprised (at qgis) if the zoom to a single selected point gave a view with lots of other, unselected, points.

In fact you will zoom to an infinite scale in case of point zooming, due to points are dimensionless. This is the actual behavior of QGIS. In my opinion it is unsatisfying. Thus I'll come back to my further statement. I think that higlighting of the selected point with respect to the actual mapscale is a better solution.

comment:7 by g_j_m, 18 years ago

Resolution: fixed
Status: newclosed

Highlighting a point when the user choses to zoom to a single selected point would be inconsistent with how qgis works with multiple selected points, lines or polygons. At the moment, when zooming to a single selected point, qgis doesn't give an infinite scale, but rather does something that is sensible most of the time - it will zoom to give an extent of about 1e-8 of the existing extent. This works fine for all the cases that I have tried. In particular, if the point is close to (0,0), it will zoom to quite a high scale, but otherwise works fine.

I consider this behaviour to be reasonable in the face of an difficult situation, and bringing in an alternative behaviour depending on how many points one selects is likely to cause confusion to the users.

As it stands, the original defect no longer exists, so I'm closing this ticket. Having an alternative way of dealing with zooming to single points is, in my opinion, an enhancement that can be placed against Release 0.9 - feel free to submit a separate ticket if you think that this would be a desirable feature.

comment:8 by (none), 15 years ago

Milestone: Version 0.8

Milestone Version 0.8 deleted

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