pdfviewer: (more code cleanup): class documentation and comments
Review URL: https://codereview.chromium.org/27043002
git-svn-id: http://skia.googlecode.com/svn/trunk@11730 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/experimental/PdfViewer/pdfparser/native/SkPdfNativeTokenizer.h b/experimental/PdfViewer/pdfparser/native/SkPdfNativeTokenizer.h
index 77bd8b5..8ed354c 100644
--- a/experimental/PdfViewer/pdfparser/native/SkPdfNativeTokenizer.h
+++ b/experimental/PdfViewer/pdfparser/native/SkPdfNativeTokenizer.h
@@ -8,15 +8,20 @@
#ifndef SkPdfNativeTokenizer_DEFINED
#define SkPdfNativeTokenizer_DEFINED
-#include "SkPdfConfig.h"
-
-#include "SkTDArray.h"
-#include "SkTDict.h"
#include <math.h>
#include <string.h>
+#include "SkPdfConfig.h"
+#include "SkTDArray.h"
+#include "SkTDict.h"
+
+// All these constants are defined by the PDF 1.4 Spec.
+
class SkPdfDictionary;
class SkPdfImageDictionary;
+class SkPdfNativeDoc;
+class SkPdfNativeObject;
+
// White Spaces
#define kNUL_PdfWhiteSpace '\x00'
@@ -49,7 +54,12 @@
// 4) vector (e.f. T type[256] .. return type[ch] ...
// 5) manually build the expression with least number of operators, e.g. for consecutive
// chars, we can use an binary equal ignoring last bit
-#define isPdfWhiteSpace(ch) (((ch)==kNUL_PdfWhiteSpace)||((ch)==kHT_PdfWhiteSpace)||((ch)==kLF_PdfWhiteSpace)||((ch)==kFF_PdfWhiteSpace)||((ch)==kCR_PdfWhiteSpace)||((ch)==kSP_PdfWhiteSpace))
+#define isPdfWhiteSpace(ch) (((ch)==kNUL_PdfWhiteSpace)|| \
+ ((ch)==kHT_PdfWhiteSpace)|| \
+ ((ch)==kLF_PdfWhiteSpace)|| \
+ ((ch)==kFF_PdfWhiteSpace)|| \
+ ((ch)==kCR_PdfWhiteSpace)|| \
+ ((ch)==kSP_PdfWhiteSpace))
#define isPdfEOL(ch) (((ch)==kLF_PdfWhiteSpace)||((ch)==kCR_PdfWhiteSpace))
@@ -73,26 +83,16 @@
const unsigned char* skipPdfWhiteSpaces(const unsigned char* buffer, const unsigned char* end);
const unsigned char* endOfPdfToken(const unsigned char* start, const unsigned char* end);
-// TODO(edisonn): typedef read and integer tyepes? make less readable...
-//typedef double SkPdfReal;
-//typedef int64_t SkPdfInteger;
-
-// an allocator only allocates memory, and it deletes it all when the allocator is destroyed
-// this would allow us not to do any garbage collection while we parse or draw a pdf, and defere it
-// while the user is looking at the image
-
-class SkPdfNativeObject;
-
-class SkPdfAllocator {
#define BUFFER_SIZE 1024
- SkTDArray<SkPdfNativeObject*> fHistory;
- SkTDArray<void*> fHandles;
- SkPdfNativeObject* fCurrent;
- int fCurrentUsed;
- SkPdfNativeObject* allocBlock();
- size_t fSizeInBytes;
-
+/** \class SkPdfAllocator
+ *
+ * An allocator only allocates memory, and it deletes it all when the allocator is destroyed.
+ * This strategy would allow us not to do any garbage collection while we parse and/or render
+ * a pdf.
+ *
+ */
+class SkPdfAllocator {
public:
SkPdfAllocator() {
fSizeInBytes = sizeof(*this);
@@ -102,9 +102,10 @@
~SkPdfAllocator();
+ // Allocates an object. It will be reset automatically when ~SkPdfAllocator() is called.
SkPdfNativeObject* allocObject();
- // TODO(edisonn): free this memory in destructor, track the usage?
+ // Allocates a buffer. It will be freed automatically when ~SkPdfAllocator() is called.
void* alloc(size_t bytes) {
void* data = malloc(bytes);
fHandles.push(data);
@@ -112,41 +113,71 @@
return data;
}
+ // Returns the number of bytes used in this allocator.
size_t bytesUsed() const {
return fSizeInBytes;
}
+
+private:
+ SkTDArray<SkPdfNativeObject*> fHistory;
+ SkTDArray<void*> fHandles;
+ SkPdfNativeObject* fCurrent;
+ int fCurrentUsed;
+
+ SkPdfNativeObject* allocBlock();
+ size_t fSizeInBytes;
};
-class SkPdfNativeDoc;
-const unsigned char* nextObject(const unsigned char* start, const unsigned char* end, SkPdfNativeObject* token, SkPdfAllocator* allocator, SkPdfNativeDoc* doc);
-
+// Type of a parsed token.
enum SkPdfTokenType {
kKeyword_TokenType,
kObject_TokenType,
};
+
+/** \struct PdfToken
+ *
+ * Stores the result of the parsing - a keyword or an object.
+ *
+ */
struct PdfToken {
- const char* fKeyword;
- size_t fKeywordLength;
- SkPdfNativeObject* fObject;
- SkPdfTokenType fType;
+ const char* fKeyword;
+ size_t fKeywordLength;
+ SkPdfNativeObject* fObject;
+ SkPdfTokenType fType;
PdfToken() : fKeyword(NULL), fKeywordLength(0), fObject(NULL) {}
};
+/** \class SkPdfNativeTokenizer
+ *
+ * Responsible to tokenize a stream in small tokens, eityh a keyword or an object.
+ * A renderer can feed on the tokens and render a pdf.
+ *
+ */
class SkPdfNativeTokenizer {
public:
- SkPdfNativeTokenizer(SkPdfNativeObject* objWithStream, SkPdfAllocator* allocator, SkPdfNativeDoc* doc);
- SkPdfNativeTokenizer(const unsigned char* buffer, int len, SkPdfAllocator* allocator, SkPdfNativeDoc* doc);
+ SkPdfNativeTokenizer(SkPdfNativeObject* objWithStream,
+ SkPdfAllocator* allocator, SkPdfNativeDoc* doc);
+ SkPdfNativeTokenizer(const unsigned char* buffer, int len,
+ SkPdfAllocator* allocator, SkPdfNativeDoc* doc);
virtual ~SkPdfNativeTokenizer();
+ // Reads one token. Returns false if there are no more tokens.
bool readToken(PdfToken* token);
- bool readTokenCore(PdfToken* token);
+
+ // Put back a token to be read in the nextToken read. Only one token is allowed to be put
+ // back. Must not necesaarely be the last token read.
void PutBack(PdfToken token);
+
+ // Reads the inline image that is present in the stream. At this point we just consumed the ID
+ // token already.
SkPdfImageDictionary* readInlineImage();
private:
+ bool readTokenCore(PdfToken* token);
+
SkPdfNativeDoc* fDoc;
SkPdfAllocator* fAllocator;
@@ -159,4 +190,9 @@
PdfToken fPutBack;
};
+const unsigned char* nextObject(const unsigned char* start, const unsigned char* end,
+ SkPdfNativeObject* token,
+ SkPdfAllocator* allocator,
+ SkPdfNativeDoc* doc);
+
#endif // SkPdfNativeTokenizer_DEFINED