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