pagination - config.go

     1  package pagination
     2  
     3  const (
     4  	defaultEnd         = 3
     5  	defaultSurrounding = 3
     6  )
     7  
     8  // Config is the configuation for a Pagination
     9  type Config struct {
    10  	Ends, Surrounding uint
    11  }
    12  
    13  // New returns a default configuration for Pagination
    14  func New() Config {
    15  	return Config{
    16  		Ends:        defaultEnd,
    17  		Surrounding: defaultSurrounding,
    18  	}
    19  }
    20  
    21  // Get returns the Section information for Pagination
    22  func (c Config) Get(currPage, lastPage uint) Pagination {
    23  	if currPage > lastPage {
    24  		lastPage = currPage
    25  	}
    26  	p := Pagination{page: currPage}
    27  	start := uint(0)
    28  	for page := uint(0); page <= lastPage; page++ {
    29  		if !(page < c.Ends || // Beginning
    30  			page > lastPage-c.Ends || // End
    31  			((c.Surrounding > currPage || page >= currPage-c.Surrounding) && page <= currPage+c.Surrounding) || // Middle
    32  			c.Ends > 0 && ((currPage-c.Surrounding-1 == c.Ends && page == c.Ends) || // Merge Begining and Middle if close enough
    33  				(currPage+c.Surrounding+1 == lastPage-c.Ends && page == lastPage-c.Ends))) { // Merge Middle and End if close enough
    34  			if page != start {
    35  				p.sections[p.numSections] = section{start, page - 1}
    36  				p.numSections++
    37  			}
    38  			start = page + 1
    39  		}
    40  	}
    41  	if start < lastPage {
    42  		p.sections[p.numSections] = section{start, lastPage}
    43  		p.numSections++
    44  	}
    45  	return p
    46  }