com.talk2object.plum.view._abstract.components.Pagingnation Maven / Gradle / Ivy

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package com.talk2object.plum.view._abstract.components;

public class Pagingnation {

	private int pageSize;
	private long totalSize;

	/**
	 * the max page numbers listed on UI
	 */
	private int maxListedPageCount = 10;

	private int currentPage = 1;

	public Pagingnation(int pageSize, long totalSize) {
		this.pageSize = pageSize;
		this.totalSize = totalSize;
	}

	public void setCurrentPage(int currentPage) {
		this.currentPage = currentPage;
	}

	public int[] getListedPages() {
		// by default, the current page number is at the center position

		int min = currentPage - maxListedPageCount / 2;
		int max = min + maxListedPageCount - 1;

		if (min < 1) {
			// shift to right
			min = getFirstPage();

			max = maxListedPageCount;
			if (max > getLastPage())
				max = getLastPage();
		}

		if (max > getLastPage()) {
			// shift to left
			max = getLastPage();

			min = max - maxListedPageCount;
			if (min < getFirstPage())
				min = getFirstPage();
		}

		int listedPageSize = (int) (max - min + 1);
		int[] pages = new int[listedPageSize];
		for (int i = 0; i < listedPageSize; i++) {
			pages[i] = min + i;
		}
		return pages;
	}

	public int getPreviousPage() {
		return currentPage - 1;
	}

	public int getNextPage() {
		return currentPage + 1;
	}

	public int getFirstPage() {
		return 1;
	}

	public int getLastPage() {
		return (int) (((totalSize - 1) / pageSize) + 1);
	}

	public void gotoFirstPage() {
		setCurrentPage(getFirstPage());
	}

	public void gotoLastPage() {
		setCurrentPage(getLastPage());
	}

	public void gotoPreviousPage() {
		setCurrentPage(getPreviousPage());
	}

	public void gotoNextPage() {
		setCurrentPage(getNextPage());
	}

	public long getPageSize() {
		return pageSize;
	}

	public void setPageSize(int pageSize) {
		this.pageSize = pageSize;
	}

	public int getCurrentPage() {
		return currentPage;
	}

	public boolean isValidPage(int page) {
		return page >= 1 && page <= getLastPage();
	}

}