Note/warning :- As of writing (Apr 2014), most of these are oriented to QGIS "1.8.0-trunk" on the Mac, using the packaged version provided by KyngChaos - which is distributed as a "System Framework" and provides other tools like GDAL etc.
However from a few places I've looked at, this doesn't seem to correspond exactly with the 1.8 release.
Some time soon I should update to 2.0
Ways to get a particular selected line, e.g. a tram route, to show above other lines in the same layer.
In QGIS 1.8 on Mac its quite hard to clearly select a particular symbol and show it clearly, just with the select tool.
- General References:
The first of these has a couple of suggestions I tried.
- This worked quite well. E.g. here is what you do:
- # Use the "new vector layer" button, and add a new version of exactly the same layer. # Drag it to just above the old layer in the rendering tab, and rename it appropriately (e.g. an '(Editing)' suffix) # Right click the newly added layer, and choose style so it appears appropriately (e.g. a different color to other one.) # Then, right-click on new layer again, and choose 'Query ...' # Now you just have to query by appropriate property e.g. "name = '8'" for tram route 8. # Voila! QGIS will now show just the feature you're interested in.
This comes from the last answer on the StackExchange site above.
In this approach, you change the Style from 'simple' to either 'categorised' or 'rule-based'. Then, use the "Symbol Layers" advanced option to change rendering order so the desired line always shows on top.
The 'rule-based' approach would be better for this purpose, but I found that the Symbol Layers box doesn't seem to work in the 1.8-Mac version of QGIS I have sadly. So one can 'hack' with the Categorised option, but its pretty awkward. From the second link above, it looks like both stability and user-interface of this rule-based stuff improves quite a bit in the final 1.8 release, and 2.0 of QGIS.
symbol to clearly