Improve toolbar border

[weisJ]

Description

Change the container of the toolbar from Box to JToolBar and use an empty border for the toolbar itself.

Motivation and Context

1. Generally toolbars are placed in a component that uses BorderLayout. When doing so it gives the LaF more context on how to paint the toolbar.

2. With the toolbar being placed in a Box container the toolbar only paints it border along the space it consumes resulting in an odd visual e.g.

   • On Metal the background is different midway through the topbar (zoom in to see it).
     

   • On Nimbus the border stops midway.
     

3. JToolBar uses the exact same layoutmanager as Box resulting in the same layout as before.

4. By giving the actual toolbar portion an EmptyBorder doubly painted borders are avoided.

How Has This Been Tested?

Layout has not been affected. See screenshots

Screenshots (if appropriate):

IntelliJ (Looks the same on the other darklaf themes):

Motif:

Metal:

Nimbus:

Windows:

Windows Classic:

Types of changes

• Visual improvement

Checklist:

• My code follows the code style of this project.
• I have updated the documentation accordingly. Not needed.

[vlsi]

Oh, this indeed looks odd.

However, it looks like a single toolbar is enough, so the following should work:

        JMeterToolBar toolPanel = JMeterToolBar.createToolbar(true);
        this.toolbar = toolPanel;
        GuiPackage guiInstance = GuiPackage.getInstance();
        guiInstance.setMainToolbar(toolbar);

        toolPanel.add(Box.createRigidArea(new Dimension(5, 15)));

[weisJ]

I though about doing exactly this but didn’t know whether it was on purpose to have the right side of the top panel separated from the left (from a component perspective not the visuals).

[vlsi]

I have no idea either, and it is not documented :-/

It looks like that was made for historical reasons only.
If we want to make the toolbar extendable, then we probably need to add explicit APIs so the plugins could contribute to the relevant sections within the toolbar.

So far I'm inclined to have a single component (which is often easier for layout) rather than a nested structure.

@pmouawad , any idea here?