MultipleEventFirererImpl with js function

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package org.richfaces.tests.metamer.ftest.extension.multipleEventFiring;

import java.util.ArrayList;
import java.util.List;

import org.openqa.selenium.JavascriptExecutor;
import org.openqa.selenium.WebElement;

import com.google.common.collect.Lists;

/**
 * @author <a href="mailto:[email protected]">Jiri Stefek</a>
 */
public class MultipleEventFirererImpl implements MultipleEventFirerer {

    private static final String COMMA_QUOTE = ",\'";
    private static final String ELEMENTS_INIT = "var $elements=[];";
    private static final String FUNCTION = "function triggerOnElement(index, event, count){for (var i = 0 ; i < count; i++){$elements[index].trigger(event);}}";
    private static final String PUSH_ELEM_END = "]));";
    private static final String PUSH_ELEM_START = "$elements.push(jQuery(arguments[";
    private static final String QUOTE_COMMA = "\',";
    private static final String TRIGGER_ON_END = ");";
    private static final String TRIGGER_ON_START = "triggerOnElement(";

    private final List<Integer> counts = Lists.newArrayList();
    private final ArrayList<WebElement> elements = Lists.newArrayList();
    private final ArrayList<String> events = Lists.newArrayList();
    private JavascriptExecutor executor;

    public MultipleEventFirererImpl(JavascriptExecutor executor) {
        this.executor = executor;
    }

    @Override
    public MultipleEventFirerer addEvent(WebElement element, int count, String eventName) {
        elements.add(element);
        counts.add(count);
        events.add(eventName);
        return this;
    }

    @Override
    public void perform() {
        executor.executeScript(prepareScript(), elements);
    }

    private String prepareElements() {
        StringBuilder sb = new StringBuilder();
        sb.append(ELEMENTS_INIT);
        sb.append(FUNCTION);
        int size = elements.size();
        for (int i = 0; i < size; i++) {
            sb.append(PUSH_ELEM_START).append(i).append(PUSH_ELEM_END);
        }
        return sb.toString();
    }

    private String prepareScript() {
        StringBuilder sb = new StringBuilder();
        sb.append(prepareElements());
        int countsSize = counts.size();
        for (int i = 0; i < countsSize; i++) {
            int count = counts.get(i);
            sb.append(TRIGGER_ON_START).append(i).append(COMMA_QUOTE).append(events.get(i)).append(QUOTE_COMMA).append(count).append(TRIGGER_ON_END);
        }
        return sb.toString();
    }
}