1: <?php
  2: 
  3: /**
  4:  * This file is part of the Nette Framework (https://nette.org)
  5:  * Copyright (c) 2004 David Grudl (https://davidgrudl.com)
  6:  */
  7: 
  8: namespace Nette\Utils;
  9: 
 10: use Nette;
 11: 
 12: 
 13: /**
 14:  * Paginating math.
 15:  *
 16:  * @author     David Grudl
 17:  *
 18:  * @property   int $page
 19:  * @property-read int $firstPage
 20:  * @property-read int|NULL $lastPage
 21:  * @property   int $base
 22:  * @property-read bool $first
 23:  * @property-read bool $last
 24:  * @property-read int|NULL $pageCount
 25:  * @property   int $itemsPerPage
 26:  * @property   int|NULL $itemCount
 27:  * @property-read int $offset
 28:  * @property-read int|NULL $countdownOffset
 29:  * @property-read int|NULL $length
 30:  */
 31: class Paginator extends Nette\Object
 32: {
 33:     /** @var int */
 34:     private $base = 1;
 35: 
 36:     /** @var int */
 37:     private $itemsPerPage = 1;
 38: 
 39:     /** @var int */
 40:     private $page;
 41: 
 42:     /** @var int|NULL */
 43:     private $itemCount;
 44: 
 45: 
 46:     /**
 47:      * Sets current page number.
 48:      * @param  int
 49:      * @return self
 50:      */
 51:     public function setPage($page)
 52:     {
 53:         $this->page = (int) $page;
 54:         return $this;
 55:     }
 56: 
 57: 
 58:     /**
 59:      * Returns current page number.
 60:      * @return int
 61:      */
 62:     public function getPage()
 63:     {
 64:         return $this->base + $this->getPageIndex();
 65:     }
 66: 
 67: 
 68:     /**
 69:      * Returns first page number.
 70:      * @return int
 71:      */
 72:     public function getFirstPage()
 73:     {
 74:         return $this->base;
 75:     }
 76: 
 77: 
 78:     /**
 79:      * Returns last page number.
 80:      * @return int|NULL
 81:      */
 82:     public function getLastPage()
 83:     {
 84:         return $this->itemCount === NULL ? NULL : $this->base + max(0, $this->getPageCount() - 1);
 85:     }
 86: 
 87: 
 88:     /**
 89:      * Sets first page (base) number.
 90:      * @param  int
 91:      * @return self
 92:      */
 93:     public function setBase($base)
 94:     {
 95:         $this->base = (int) $base;
 96:         return $this;
 97:     }
 98: 
 99: 
100:     /**
101:      * Returns first page (base) number.
102:      * @return int
103:      */
104:     public function getBase()
105:     {
106:         return $this->base;
107:     }
108: 
109: 
110:     /**
111:      * Returns zero-based page number.
112:      * @return int
113:      */
114:     protected function getPageIndex()
115:     {
116:         $index = max(0, $this->page - $this->base);
117:         return $this->itemCount === NULL ? $index : min($index, max(0, $this->getPageCount() - 1));
118:     }
119: 
120: 
121:     /**
122:      * Is the current page the first one?
123:      * @return bool
124:      */
125:     public function isFirst()
126:     {
127:         return $this->getPageIndex() === 0;
128:     }
129: 
130: 
131:     /**
132:      * Is the current page the last one?
133:      * @return bool
134:      */
135:     public function isLast()
136:     {
137:         return $this->itemCount === NULL ? FALSE : $this->getPageIndex() >= $this->getPageCount() - 1;
138:     }
139: 
140: 
141:     /**
142:      * Returns the total number of pages.
143:      * @return int|NULL
144:      */
145:     public function getPageCount()
146:     {
147:         return $this->itemCount === NULL ? NULL : (int) ceil($this->itemCount / $this->itemsPerPage);
148:     }
149: 
150: 
151:     /**
152:      * Sets the number of items to display on a single page.
153:      * @param  int
154:      * @return self
155:      */
156:     public function setItemsPerPage($itemsPerPage)
157:     {
158:         $this->itemsPerPage = max(1, (int) $itemsPerPage);
159:         return $this;
160:     }
161: 
162: 
163:     /**
164:      * Returns the number of items to display on a single page.
165:      * @return int
166:      */
167:     public function getItemsPerPage()
168:     {
169:         return $this->itemsPerPage;
170:     }
171: 
172: 
173:     /**
174:      * Sets the total number of items.
175:      * @param  int (or NULL as infinity)
176:      * @return self
177:      */
178:     public function setItemCount($itemCount)
179:     {
180:         $this->itemCount = ($itemCount === FALSE || $itemCount === NULL) ? NULL : max(0, (int) $itemCount);
181:         return $this;
182:     }
183: 
184: 
185:     /**
186:      * Returns the total number of items.
187:      * @return int|NULL
188:      */
189:     public function getItemCount()
190:     {
191:         return $this->itemCount;
192:     }
193: 
194: 
195:     /**
196:      * Returns the absolute index of the first item on current page.
197:      * @return int
198:      */
199:     public function getOffset()
200:     {
201:         return $this->getPageIndex() * $this->itemsPerPage;
202:     }
203: 
204: 
205:     /**
206:      * Returns the absolute index of the first item on current page in countdown paging.
207:      * @return int|NULL
208:      */
209:     public function getCountdownOffset()
210:     {
211:         return $this->itemCount === NULL
212:             ? NULL
213:             : max(0, $this->itemCount - ($this->getPageIndex() + 1) * $this->itemsPerPage);
214:     }
215: 
216: 
217:     /**
218:      * Returns the number of items on current page.
219:      * @return int|NULL
220:      */
221:     public function getLength()
222:     {
223:         return $this->itemCount === NULL
224:             ? $this->itemsPerPage
225:             : min($this->itemsPerPage, $this->itemCount - $this->getPageIndex() * $this->itemsPerPage);
226:     }
227: 
228: }
229: