57 lines
1.9 KiB
C++
57 lines
1.9 KiB
C++
#ifndef PAGINATOR_HPP
|
|
#define PAGINATOR_HPP
|
|
#include <utility>
|
|
|
|
class Paginator {
|
|
public:
|
|
Paginator() = default;
|
|
Paginator(int pageSize, int total, int page = 1) : pageSize(pageSize), total(total), page(page)
|
|
{
|
|
computePages();
|
|
};
|
|
~Paginator() = default;
|
|
// Getters
|
|
int getPageSize() const { return pageSize; }
|
|
int getLines() const
|
|
{
|
|
auto [start, end] = getOffset();
|
|
return std::min(pageSize, end - start + 1);
|
|
}
|
|
int getPage() const { return page; }
|
|
int getTotal() const { return total; }
|
|
int getPages() const { return numPages; }
|
|
std::pair<int, int> getOffset() const
|
|
{
|
|
return { (page - 1) * pageSize, std::min(total - 1, page * pageSize - 1) };
|
|
}
|
|
// Setters
|
|
void setTotal(int total) { this->total = total; computePages(); }
|
|
void setPageSize(int page) { this->pageSize = page; computePages(); }
|
|
bool setPage(int page) { return valid(page) ? this->page = page, true : false; }
|
|
// Utils
|
|
bool valid(int page) const { return page > 0 && page <= numPages; }
|
|
bool hasPrev(int page) const { return page > 1; }
|
|
bool hasNext(int page) const { return page < getPages(); }
|
|
bool addPage() { return page < numPages ? ++page, true : false; }
|
|
bool subPage() { return page > 1 ? --page, true : false; }
|
|
std::string to_string() const
|
|
{
|
|
auto offset = getOffset();
|
|
return "Paginator: { pageSize: " + std::to_string(pageSize) + ", total: " + std::to_string(total)
|
|
+ ", page: " + std::to_string(page) + ", numPages: " + std::to_string(numPages)
|
|
+ " Offset [" + std::to_string(offset.first) + ", " + std::to_string(offset.second) + "]}";
|
|
}
|
|
private:
|
|
void computePages()
|
|
{
|
|
numPages = pageSize > 0 ? (total + pageSize - 1) / pageSize : 0;
|
|
if (page > numPages) {
|
|
page = numPages;
|
|
}
|
|
}
|
|
int pageSize;
|
|
int total;
|
|
int page;
|
|
int numPages;
|
|
};
|
|
#endif |