Bug 320285 Messages inteneded for developers in the error log
The message "unsupported: isEditorAreaVisible" appears in the error log during the normal run of e4 SDK. (For instance, starting the e4 SDK on an clean workspace produces two of those messages.)
bundles/org.eclipse.e4.ui.workbench.addons.swt/src/org/eclipse/e4/ui/workbench/addons/perspectiveswitcher/PerspectiveSwitcher.java
.getWorkbench().getPerspectiveRegistry());
		dialog.open();
		if (dialog.getReturnCode() == Window.CANCEL) {
			return;
		}
		IPerspectiveDescriptor descriptor = dialog.getSelection();
		if (descriptor != null) {
			MPerspective persp = getPerspectiveFor(descriptor);
			if (persp != null) {
				if (!persp.isToBeRendered())
					persp.setToBeRendered(true);
				persp.getParent().setSelectedElement(persp);
			} else {
				openPerspective((PerspectiveDescriptor) descriptor);
			}
		}
	}
	private void openMenuFor(ToolItem item, MPerspective persp) {
		final Menu menu = new Menu(psTB);
		menu.setData(persp);
		if (persp.isVisible()) {
			addCloseItem(menu);
		}
		if (persp.getParent().getSelectedElement() == persp) {
			addResetItem(menu);
		}
		new MenuItem(menu, SWT.SEPARATOR);
		
		addShowTextItem(menu);
		Rectangle bounds = item.getBounds();