Opened 10 years ago

Last modified 10 years ago

#3253 new enhancement

Enhancement: option to "trim other layers to match"

Reported by: Alister Owned by: nobody
Priority: minor: annoyance Milestone: Version 2.0.0
Component: Symbology Version:
Keywords: Cc:
Must Fix for Release: No Platform: All
Platform Version: Awaiting user input: no


Task: It would be useful to be able to use a polygon to temporarily mask other layers. e.g. if you have a layer of boundaries for catchments (or provinces or something), to only display content within one particular catchment.

Current way of achieving the task: I think the most flexible way to achieve this at the moment is:

  1. create a set of new mask layers, by subtracting each catchment from a polygon bigger than the area of interest.
  2. put these layers above everything else.
  3. only turn on the mask layer which corresponds to the area of interest.

This method is fine for the work I do myself, because I work with only a small number of areas. But it would not be practical with a large number.

Proposed new feature I think the best way to do it would be to add an option "trim other layers to extent" (there is probably a better way of wording this - some people might think "extent" implies a rectangular area or something). This would allow the user to mask all map content outside a polygon layer or whatever subset of the layer is defined (by the query builder). A logical place for the option would be on the "general" tab in the "layer properties" dialogue, as this is where the layer subset is shown.

N.B. sorry if I haven't picked the appropriate Component; I'm not sure which it should be.

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untitled.JPG (69.7 KB) - added by Alister 10 years ago.
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Change History (3)

comment:1 Changed 10 years ago by Alister

Current way of achieving the task: I think the most flexible way to achieve this at the moment is:...

But this obviously doesn't work if you have labelled layers - labels are shown above all layers, so you can still see the labels for hidden features. In this case I think the only solution is to create a set of layers cropped to each region, which would be very impractical if you had a lot of regions.

Also, when a feature is selected the hidden parts of it can still be seen (I guess this is desirable - at least when editing the feature). See the screenshot.

Changed 10 years ago by Alister

Attachment: untitled.JPG added

Screenshot relating to first comment

comment:2 Changed 10 years ago by Alister

Just to pick up a possible search by someone else looking for this functionality:

I see that MapInfo? implements this with two entries in the "Map" menu: "Set clip region" and "Clip region on/off".

The MapInfo? implementation could be improved on ;)

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