Add classes for indirect objects

index.php

@@ -2,105 +2,179 @@
 class Writer
 {
 	protected $offset = 0;
-	
+
 	public function __construct()
 	{
 		header('Content-Type: application/pdf');
 	}
-	
+
 	public function getOffset()
 	{
 		return $this->offset;
 	}
-	
+
 	public function write($s)
 	{
 		echo $s;
 		$this->offset += strlen($s);
 	}
-	
+
 	public function writeLn($s)
 	{
 		$this->write("$s\r\n");
 	}
+
+	public function writeMap(array $map)
+	{
+		foreach ($map as $key => $value) {
+			$this->writeLn("/{$key} {$value}");
+		}
+	}
 }
 
 
-class Document
+abstract class IndirectObject
 {
-	protected $index = 1;
-	protected $objects = [];
-	protected $offsets = [];
-	protected $xrefOffset;
-
-	public function createIndirectObject($map)
+	abstract public function getMap();
+}
+
+class Catalog  extends IndirectObject
+{
+	protected $pages;
+
+	public function setPages(Pages $pages)
 	{
-		$this->objects[$this->index] = $map;
-		$this->index++;
+		$this->pages = $pages;
 	}
-
-
-	public function output(Writer $writer)
+
+	public function getMap()
 	{
-		$this->createIndirectObject([
+		return [
 			'Type' => '/Catalog',
 			'Pages' => '2 0 R',
-		]);
-
-		$this->createIndirectObject([
+		];
+	}
+}
+
+class Pages  extends IndirectObject
+{
+	protected $pages = [];
+
+	public function addPage(Page $page)
+	{
+		$this->pages[] = $page;
+	}
+
+	public function getMap()
+	{
+		return [
 			'Type' => '/Pages',
 			'Kids' => '[ 3 0 R ]',
 			'Count' => 1,
-		]);
-
-		$this->createIndirectObject([
+		];
+	}
+}
+
+class Page  extends IndirectObject
+{
+	protected $parent;
+
+	public function __construct(Pages $parent)
+	{
+		$this->parent = $parent;
+	}
+
+	public function getMap()
+	{
+		return [
 			'Type' => '/Page',
 			'Parent' => '2 0 R',
 			'Resources' => '<< >>',
 			'MediaBox' => '[ 0 0 1000 1000 ]',
-		]);
-
-
+		];
+	}
+}
+
+
+class Document
+{
+	protected $index = 1;
+	protected $objects = [];
+	protected $offsets = [];
+	protected $xrefOffset;
+
+	protected $catalog;
+	protected $currentPages;
+	protected $currentPage;
+
+	public function __construct()
+	{
+		$catalog = new Catalog();
+		$this->registerIndirectObject($catalog);
+
+		$pages = new Pages();
+		$this->registerIndirectObject($pages);
+
+		$page = new Page($pages);
+		$this->registerIndirectObject($page);
+
+		$catalog->setPages($pages);
+		$pages->addPage($page);
+
+		$this->catalog = $catalog;
+		$this->currentPages = $pages;
+		$this->currentPage = $page;
+	}
+
+
+	public function registerIndirectObject($object)
+	{
+		$this->objects[$this->index] = $object;
+		$this->index++;
+	}
+
+
+
+	public function output(Writer $writer)
+	{
 		$this->outputHeader($writer);
-		foreach ($this->objects as $id => $map) {
-			$this->outputIndirectObject($writer, $id, $map);
+		foreach ($this->objects as $id => $object) {
+			$this->outputIndirectObject($writer, $id, $object);
 		}
-		
+
 		$this->outputXref($writer);
 		$this->outputTrailer($writer);
 		$this->outputXrefOffset($writer);
 		$this->outputFooter($writer);
 	}
-	
-	
+
+
 	public function outputHeader(Writer $writer)
 	{
 		$writer->writeLn("%PDF-1.2");
 		$writer->writeLn("");
 	}
-	
-	
-	public function outputIndirectObject(Writer $writer, $id, $map)
+
+
+	public function outputIndirectObject(Writer $writer, $id, $object)
 	{
 		$this->offsets[$id] = $writer->getOffset();
-		
+
 		$writer->writeLn("{$id} 0 obj");
 		$writer->writeLn("<<");
-		foreach ($map as $key => $value) {
-			$writer->writeLn("/{$key} {$value}");
-		}
+		$writer->writeMap($object->getMap());
 		$writer->writeLn(">>");
 		$writer->writeLn("endobj");
 		$writer->writeLn("");
 	}
-	
+
 
 	public function outputXref(Writer $writer)
 	{
 		$this->xrefOffset = $writer->getOffset();
-		
+
 		$count = count($this->objects);
-		
+
 		$writer->writeLn("xref");
 		$writer->writeLn(sprintf("0 {$count}"));
 		$writer->writeLn("0000000000 65535 f");
@@ -109,24 +183,24 @@ public function outputXref(Writer $writer)
 		}
 		$writer->writeLn("");
 	}
-	
+
 	public function outputTrailer(Writer $writer)
 	{
 		$count = count($this->objects);
-		
+
 		$writer->writeLn("trailer");
 		$writer->writeLn("<<");
 		$writer->writeLn("/Size {$count}");
 		$writer->writeLn("/Root 1 0 R");
 		$writer->writeLn(">>");
 	}
-	
+
 	public function outputXrefOffset(Writer $writer)
 	{
 		$writer->writeLn("startxref");
 		$writer->writeLn($this->xrefOffset);
 	}
-	
+
 	public function outputFooter(Writer $writer)
 	{
 		$writer->writeLn("%%EOF");