void setActiveProgram(Program program) {

		viewProgramDiffAction.setEnabled(program != null);

		boolean enabled = program != null && !plugin.isTaskInProgress();
		openCloseDiffViewAction.setEnabled(enabled);

		if (enabled) {
			if (openCloseDiffViewAction.isSelected()) {
				// we are diffing--is the current program the diff program?
				Program firstProgram = plugin.getFirstProgram();
				if (firstProgram == program) {
					openCloseDiffViewAction.setDescription("Close Diff View");
				}
				else {
					openCloseDiffViewAction.setDescription("Bring Diff View to Front");
				}
			}
		}
		else {
			// no active diff
			openCloseDiffViewAction.setDescription("Open Diff View");
		}
	}
Called to adjust or add/remove the Program Diff's actions when a program
becomes the active program.
@param program the newly active program
Ghidra/Features/ProgramDiff/src/main/java/ghidra/app/plugin/core/diff/DiffActionManager.java