feat: add getPreviousPageNumber() and getNextPageNumber()

Author: kenjis

system/Pager/PagerRenderer.php

@@ -431,4 +431,24 @@ public function getLastPageNumber(): int
 	{
 		return $this->last;
 	}
+
+	/**
+	 * Returns the previous page number.
+	 *
+	 * @return integer|null
+	 */
+	public function getPreviousPageNumber(): ?int
+	{
+		return ($this->current === 1) ? null : $this->current - 1;
+	}
+
+	/**
+	 * Returns the next page number.
+	 *
+	 * @return integer|null
+	 */
+	public function getNextPageNumber(): ?int
+	{
+		return ($this->current === $this->pageCount) ? null : $this->current + 1;
+	}
 }

tests/system/Pager/PagerRendererTest.php

@@ -595,4 +595,68 @@ public function testGetPageNumberSetSurroundCount()
 		$this->assertEquals(5, $pager->getCurrentPageNumber());
 		$this->assertEquals(7, $pager->getLastPageNumber());
 	}
+
+	public function testGetPreviousPageNumber()
+	{
+		$uri     = $this->uri;
+		$details = [
+			'uri'         => $uri,
+			'pageCount'   => 10,
+			'currentPage' => 5,
+			'total'       => 100,
+			'segment'     => 2,
+		];
+		$pager   = new PagerRenderer($details);
+		$pager->setSurroundCount(2);
+
+		$this->assertEquals(4, $pager->getPreviousPageNumber());
+	}
+
+	public function testGetPreviousPageNumberNull()
+	{
+		$uri     = $this->uri;
+		$details = [
+			'uri'         => $uri,
+			'pageCount'   => 10,
+			'currentPage' => 1,
+			'total'       => 100,
+			'segment'     => 2,
+		];
+		$pager   = new PagerRenderer($details);
+		$pager->setSurroundCount(2);
+
+		$this->assertEquals(null, $pager->getPreviousPageNumber());
+	}
+
+	public function testGetNextPageNumber()
+	{
+		$uri     = $this->uri;
+		$details = [
+			'uri'         => $uri,
+			'pageCount'   => 10,
+			'currentPage' => 5,
+			'total'       => 100,
+			'segment'     => 2,
+		];
+		$pager   = new PagerRenderer($details);
+		$pager->setSurroundCount(2);
+
+		$this->assertEquals(6, $pager->getNextPageNumber());
+	}
+
+	public function testGetNextPageNumberNull()
+	{
+		$uri     = $this->uri;
+		$details = [
+			'uri'         => $uri,
+			'pageCount'   => 10,
+			'currentPage' => 10,
+			'total'       => 100,
+			'segment'     => 2,
+		];
+		$pager   = new PagerRenderer($details);
+		$pager->setSurroundCount(2);
+
+		$this->assertEquals(null, $pager->getNextPageNumber());
+	}
 }