WorldControl settings not fully functional

[jrutgeer]

Environment

• OS Version: Ubuntu 22.04
• Gazebo Garden built from source

Description

1. The worldcontrol plugin reads parameter start_paused but it does not seem to have an effect: the simulation always starts 'paused' irrespective of the value of start_paused, see xml and screenshot below.

2. If I read the code correctly, start_paused is used:

   • Only if play_pause is defined in the XML,
   • And if the value for play_pause is true (i.e. the start/pause button is visible).
   • This seems to defeat the purpose? I.e. I would like to start the simulation unpaused, and not show the start/pause button.

3. The worldcontrol plugin reads parameters play_pause and step from the XML config in order to show/hide the corresponding buttons. They are hidden if the value is false.
   However for the step button, the free space remains and the 'Steps' popup still shows upon hoover over the non-visible step button.

<plugin filename="WorldControl" name="World control">
    <gz-gui>
        <title>World control</title>
        <anchors target="3D View">
            <line own="left" target="left"/>
            <line own="bottom" target="bottom"/>
        </anchors>
        <property key="x" type="double">0</property>
        <property key="y" type="double">1256</property>
        <property key="z" type="double">1</property>
        <property key="width" type="double">1199</property>
        <property key="height" type="double">72</property>
        <property key="opacity" type="double">1</property>
        <property key="enabled" type="bool">true</property>
        <property key="visible" type="bool">true</property>
        <property key="state" type="string">floating</property>
        <property key="showTitleBar" type="bool">false</property>
    </gz-gui>
    <play_pause>true</play_pause>
    <step>false</step>
    <start_paused>false</start_paused>
    <use_event>true</use_event>
</plugin>