Freezing legend on map composer so that it stops updating when changing symbols on map?

Question

This seems like a counter intuitive question, but is there a way to freeze the legend so that it stops updating itself in the print composer?

My auto-update box is unticked for the legend, but the legend symbols keep updating with every map change/refresh. I want the symbol sizes to stay the same regardless of what I change in my main map.

I've tried to save the legend as an image and re-importing the image as the legend, but the image is not scalable and therefore looks very pixelated in comparison to the rest of the map.

I am currently using Qgis 2.4

Answer 1

The easiest way to achieve this is to have a separate dedicated "legend" layer.

You can make this layer not visible in the map and just use it for the legend.

This will allow you to have larger markers for the legend for example, or for scaled symbology it might even be the only way to do it.

Answer 2

You can do this by locking your layer(s) as shown below.

Map > item Properties > Layers

By doing this, all what you will do in the canvas will not be reflected in the print composer until you uncheck the button.

This may be useful when you have more than one map in your print composer, but you dont want to duplicate each layers.

Answer 3

As far as I know, QGIS symbols will always change to match what you set in the layer properties. The update checkbox concerns the layers present (or not) in your legend.

But my main concern is that what you are trying to achieve is actually a cartography no-no. Legend items matching feature symbology is a basic rule.

Of course, this applies mostly to point features. If you want to make line or polygon legend items longer/larger or shorter/smaller, you can modify the legend parameters as long as the color, line width, and patterns are the same.

If you really want to go with differently sized symbols in your legend, there are workarounds. You could check out this question.