Customizable layouts - fully functional

[chapulina]

Related to #207

Since this PR we've been able to load GUI configs from the command line with --gui-config and default to ~/.ignition/gazebo/gui.config when no <gui> was specified on SDF.

But because of issue #207, we couldn't really reuse configuration files across worlds that have different names. Which meant that the 2 features above couldn't really be used.

This PR, together with gazebosim/gz-gui#104, allow us to remove custom topics and services from SDF files. This means we can rely on the default gui.config all the time!

More advantages:

• This lowers the bar for using Gazebo-classic SDF worlds with Ignition, because it's one less thing for them to set.
• 3,069 deleted lines!

See the new tutorial for more info.

⚠️ Delete your existing default file to see the effects of this PR: rm ~/.ignition/gazebo/gui.config

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👇 that's what loading ign gazebo shapes.sdf looks like now.

Fix

The fix is based on setting the worldNames on the MainWindow so that any plugin can find them. This means that even pure ign-gui plugins like WorldControl and WorldStats can access world names if they want.

This is not a solution to #207, but it makes it easier to write GUI plugins that will work with whatever world is currently loaded.

New layout

I tweaked a bit the default gui.config file so it includes more plugins. I used a gray background for shapes and transform control because it needs to look ok on both light and dark themes.

Deleted lines

I went over all SDF files and:

• Deleted the <topic>s and <service> from WorldControl and WorldStats
• If the world was using the default camera pose -6 0 6 0 0.5 0 and wasn't loading any plugin that's not on gui.config, I deleted the entire <gui> block so the default is used.
• For a couple of worlds, like rolling_shapes, I moved things so that they work well with the default camera angle.

[codecov]

Codecov Report

Merging #278 into ign-gazebo2 will decrease coverage by 4.16%.
The diff coverage is 80.00%.

@@               Coverage Diff               @@
##           ign-gazebo2     #278      +/-   ##
===============================================
- Coverage        82.33%   78.16%   -4.17%     
===============================================
  Files              172      183      +11     
  Lines             9304     9917     +613     
===============================================
+ Hits              7660     7752      +92     
- Misses            1644     2165     +521     

Impacted Files	Coverage Δ
src/gui/GuiRunner.cc	55.00% <66.66%> (+3.57%)	⬆️
src/gui/Gui.cc	65.25% <100.00%> (ø)
.../plugins/component_inspector/ComponentInspector.hh	28.57% <0.00%> (ø)
src/gui/plugins/modules/EntityContextMenu.cc	19.14% <0.00%> (ø)
src/gui/plugins/modules/EntityContextMenu.hh	100.00% <0.00%> (ø)
.../gui/plugins/transform_control/TransformControl.hh	100.00% <0.00%> (ø)
src/gui/plugins/shapes/Shapes.hh	100.00% <0.00%> (ø)
src/gui/plugins/entity_tree/EntityTree.hh	100.00% <0.00%> (ø)
.../plugins/component_inspector/ComponentInspector.cc	9.41% <0.00%> (ø)
include/ignition/gazebo/gui/GuiEvents.hh	0.00% <0.00%> (ø)
... and 6 more

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[caguero]

This is a great change! @chapulina and I were already talking about how to propagate the default gui.config to the users that have an existing file already. I can't think of a perfect way to do it. Maybe my only suggestion is to tweak the tutorial adding a note in this section:

If you ever want to restore default settings, just delete that file, and the
next time Gazebo is started a new file will be created with default values:

rm $HOME/.ignition/gazebo/gui.config

to reflect that another reason for removing this file might be to receive the updated version of the default configuration.

[chapulina]

reflect that another reason for removing this file might be to receive the updated version of the default configuration.

Thanks, @caguero . Updated the tutorial in 2cd4b10