HelloAction.java

package edu.cmu.empty;

import com.intellij.openapi.actionSystem.AnAction;
import com.intellij.openapi.actionSystem.AnActionEvent;
import com.intellij.openapi.project.Project;
import com.intellij.openapi.ui.Messages;
import com.intellij.openapi.ui.popup.JBPopupFactory;
import com.intellij.openapi.ui.popup.ListPopup;
import com.intellij.openapi.ui.popup.PopupStep;
import com.intellij.openapi.ui.popup.util.BaseListPopupStep;

public class HelloAction extends AnAction {
    public HelloAction() {
        super("Hello");
    }

    public void actionPerformed(AnActionEvent event) {
        Project project = event.getProject();
        final String query = Messages.showInputDialog(project,"Enter your query:","Query",
                Messages.getQuestionIcon());

        ListPopup lp = JBPopupFactory.getInstance().createListPopup(new BaseListPopupStep<String>("Your query is " + query,
                "Choice1", "Choice2") {
            @Override
            public PopupStep onChosen(String selectedValue, boolean finalChoice) {
                System.err.println(selectedValue);
                return super.onChosen(selectedValue, finalChoice);
            }
        });
        lp.showInFocusCenter();

    }
}