Bug 34159 [Tasks] First three columns of Task List too wide w/native table
The type, completion, and priority columns of the Task list using the native table widget on MacOS X are much wider than are necessary for displaying the icons in those columns and appear not to be resizable.
bundles/org.eclipse.ui.views/src/org/eclipse/ui/views/tasklist/TaskList.java
void partActivated(IWorkbenchPart part) {
		if (part == focusPart)
			return;
		if (focusSelectionProvider != null) {
			focusSelectionProvider.removeSelectionChangedListener(
				focusSelectionChangedListener);
			focusSelectionProvider = null;
		}
		focusPart = part;
		if (focusPart != null) {
			focusSelectionProvider = focusPart.getSite().getSelectionProvider();
			if (focusSelectionProvider != null) {
				focusSelectionProvider.addSelectionChangedListener(
					focusSelectionChangedListener);
				updateFocusResource(focusSelectionProvider.getSelection());
			} else {
				updateFocusResource(null);
			}
		}
	}
	void partClosed(IWorkbenchPart part) {
		if (part != focusPart)
			return;
		if (focusSelectionProvider != null) {
			focusSelectionProvider.removeSelectionChangedListener(
				focusSelectionChangedListener);
			focusSelectionProvider = null;
		}
		focusPart = null;
	}