slightly modified PaginationBar

PaginationBar.java

/**
 * Created by smallufo on 2016-03-21.
 */
package destiny.vaadin.components;

import com.vaadin.server.FontAwesome;
import com.vaadin.ui.Alignment;
import com.vaadin.ui.Button;
import com.vaadin.ui.Label;
import com.vaadin.ui.themes.ValoTheme;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.vaadin.viritin.button.MButton;
import org.vaadin.viritin.layouts.MHorizontalLayout;

import java.util.function.Supplier;

/**
 * ref
 * https://github.com/viritin/viritin/blob/master/src/test/java/org/vaadin/viritin/it/MTableWithTraditionalPaging.java
 * change to  1-based paging
 */
public class PaginationBar extends MHorizontalLayout {

  private Logger logger = LoggerFactory.getLogger(getClass());

  private PagingListener listener;

  private int currentPage = 1;

  private Button first, previous , next, last;

  private final Label status = new Label();

  /** total pages */
  private final Supplier<Integer> pagesSupplier;


  private Button.ClickListener handler = new Button.ClickListener() {
    @Override
    public void buttonClick(Button.ClickEvent event) {
      if (event.getButton() == first) {
        currentPage = 1;
      }
      else if (event.getButton() == last) {
        currentPage = pagesSupplier.get() ;
      }
      else if (event.getButton() == next) {
        currentPage++;
      }
      else if (event.getButton() == previous) {
        currentPage--;
      }
      updateState();
      listener.pageRequested(currentPage);
    }
  };

  private void updateState() {
    final boolean hasPrev = currentPage > 1;
    first.setEnabled(hasPrev);
    previous.setEnabled(hasPrev);
    final boolean hasNext = currentPage < pagesSupplier.get() ;
    logger.debug("currentPage = {} , pages = {} , hasNext = {}", currentPage, pagesSupplier.get(), hasNext);
    next.setEnabled(hasNext);
    last.setEnabled(hasNext);
    status.setValue(currentPage + "/" + pagesSupplier.get());
  }


  public interface PagingListener {

    /** 1-based */
    void pageRequested(int page);
  }


  public PaginationBar(PagingListener listener, int pageSize, Supplier<Long> countSupplier) {
    this.listener = listener;

    this.pagesSupplier = () -> {
      long total = countSupplier.get();
      return (int) (total % pageSize == 0 ? total / pageSize : total / pageSize + 1);
    };


    this.first = new MButton(FontAwesome.FAST_BACKWARD, handler).withStyleName(ValoTheme.BUTTON_BORDERLESS);
    this.previous = new MButton(FontAwesome.BACKWARD, handler).withStyleName(ValoTheme.BUTTON_BORDERLESS);
    this.next = new MButton(FontAwesome.FORWARD, handler).withStyleName(ValoTheme.BUTTON_BORDERLESS);
    this.last = new MButton(FontAwesome.FAST_FORWARD, handler).withStyleName(ValoTheme.BUTTON_BORDERLESS);

    updateState();
    addComponents(first, previous, status, next, last);
    alignAll(Alignment.MIDDLE_CENTER);
    withFullWidth();
  }
}