topoviewer: use QgsMapCanvasLayer to load layers with visibility=off

[qgib]

Author Name: Sandro Santilli (@strk)
Original Redmine Issue: 6655

Redmine category:db_manager
Assignee: Sandro Santilli

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When loading big topologies qgis still renders the layers as first thing, before we get a chance of setting visibility off.
This means you can enter the "PAL loop of death" (that is a situation in which labelling kill your CPU).

The PAL issue is not available at the moment (or I can't find it).
But I swear it's there (qgis still hasn't finished loading the project I asked it to open at least 2 minutes before I started writing this ticket)

[qgib]

Author Name: Giuseppe Sucameli (@brushtyler)

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How many layers do you load at the same time?
If more than one, consider to set the render flag to false before loading layers using ```iface.mapCanvas().setRenderFlag(False)

After loading each layer you can set it as invisible using ```iface.legendInterface().setLayerVisible(vl, False)

[qgib]

Author Name: Sandro Santilli (@strk)

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Those calls are already there.

[qgib]

Author Name: Sandro Santilli (@strk)

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Ok one problem was that I did use the setVisibleFlag before adding to legend (for some layers).
This I'm going to fix right now.

But still I'll want to look at NatanW suggestion:
22:41 < NathanW> strk: you wrap it in a QgsMapCanvasLayer and set the visable flag
22:42 < NathanW> QgsMapCanvas take a list of QgsMapCanvasLayer in it's setLayerSet method

PAL is still killing me, but only when I click on the visibility checkbox :/
See #15833 for that one

[qgib]

Author Name: Sandro Santilli (@strk)

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Ok I took a look and setLayerSet seems to be for replacing the whole layer set. Not something I want to do here.
So this is closed.

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• resolution was changed from to fixed
• done_ratio was changed from 0 to 100
• status_id was changed from Open to Closed