Support linearized loading

public/fpdf_dataavail.h

Index: public/fpdf_dataavail.h
diff --git a/public/fpdf_dataavail.h b/public/fpdf_dataavail.h
index c17f0311ab3e599387f3efc1432433e19ea2cfc2..7948bf2cd9cb5f83fe417cac0a9edf4180f76eab 100644
--- a/public/fpdf_dataavail.h
+++ b/public/fpdf_dataavail.h
@@ -12,9 +12,11 @@
 #include "fpdfview.h"
 
 /** The result of the process which check linearized PDF. */
-#define FSDK_IS_LINEARIZED 1
-#define FSDK_NOT_LINEARIZED 0
-#define FSDK_UNKNOW_LINEARIZED -1
+#define PDF_FILE_UNKNOW -1
+#define PDF_FILE_NOTLINEARIZED 0
+#define PDF_FILE_LINEARIZED 1
+#define PDF_FORM_NOTAVAIL 0
+#define PDF_FORM_AVAIL 1
 
 #ifdef __cplusplus
 extern "C" {
@@ -130,17 +132,16 @@ typedef struct _FX_DOWNLOADHINTS {
 *           hints       -   Pointer to a download hints interface, receiving
 * generated hints
 * Return value:
-*           Non-zero for page is fully available, 0 for page not yet available.
+*           true is fully available, false for page not yet available.
 * Comments:
 *           The application should call this function whenever new data arrived,
 * and process all the
-*           generated download hints if any, until the function returns non-zero
-* value. Then the
-*           application can call FPDFAvail_GetDocument() to get a document
+*           generated download hints if any, until the function returns true.
+* Then the application can call FPDFAvail_GetDocument() to get a document
 * handle.
 */
-DLLEXPORT int STDCALL FPDFAvail_IsDocAvail(FPDF_AVAIL avail,
-                                           FX_DOWNLOADHINTS* hints);
+DLLEXPORT FPDF_BOOL STDCALL
+FPDFAvail_IsDocAvail(FPDF_AVAIL avail, FX_DOWNLOADHINTS* hints);
 
 /**
 * Function: FPDFAvail_GetDocument
@@ -189,19 +190,18 @@ DLLEXPORT int STDCALL FPDFAvail_GetFirstPageNum(FPDF_DOCUMENT doc);
 *           hints       -   Pointer to a download hints interface, receiving
 * generated hints
 * Return value:
-*           Non-zero for page is fully available, 0 for page not yet available.
+*           true is fully available, false for page not yet available.
 * Comments:
 *           This function call be called only after FPDFAvail_GetDocument if
 * called.
 *           The application should call this function whenever new data arrived,
 * and process all the
-*           generated download hints if any, until the function returns non-zero
-* value. Then the
-*           application can perform page loading.
+*           generated download hints if any, until the function returns true.
+* Then the application can perform page loading.
 */
-DLLEXPORT int STDCALL FPDFAvail_IsPageAvail(FPDF_AVAIL avail,
-                                            int page_index,
-                                            FX_DOWNLOADHINTS* hints);
+DLLEXPORT FPDF_BOOL STDCALL FPDFAvail_IsPageAvail(FPDF_AVAIL avail,
+                                                  int page_index,
+                                                  FX_DOWNLOADHINTS* hints);
 
 /**
 * Function: FPDFAvail_ISFormAvail
@@ -243,18 +243,18 @@ DLLEXPORT int STDCALL FPDFAvail_IsFormAvail(FPDF_AVAIL avail,
 *           avail       -   Handle to document availability provider returned by
 * FPDFAvail_Create
 * Return value:
-*           return TRUE means the document is linearized PDF else not.
-*           FSDK_IS_LINEARIZED is a linearize file.
-*           FSDK_NOT_LINEARIZED is not a linearize file.
-*           FSDK_UNKNOW_LINEARIZED don't know whether the file is a linearize
-* file.
+*           PDF_FILE_LINEARIZED is a linearize file.
+*           PDF_FILE_NOTLINEARIZED is not a linearize file.
+*           PDF_FILE_UNKNOW doesn't know whether the file is a linearize file.
+*
 * Comments:
-*           It return TRUE/FALSE as soon as we have first 1K data.  If the
-* file's size less than
-*           1K,we don't known whether the PDF is a linearized file.
+*           It return PDF_FILE_LINEARIZED or PDF_FILE_NOTLINEARIZED as soon as
+*           we have first 1K data.  If the file's size less than 1K, it returns
+*           PDF_FILE_UNKNOW because there is not enough information to
+*           tell whether a PDF file is a linearized file or not.
 *
 */
-DLLEXPORT FPDF_BOOL STDCALL FPDFAvail_IsLinearized(FPDF_AVAIL avail);
+DLLEXPORT int STDCALL FPDFAvail_IsLinearized(FPDF_AVAIL avail);
 
 #ifdef __cplusplus
 }