CGPDFPage Reference

Overview

The CGPDFPageRef opaque type represents a page in a PDF document.

Functions by Task

Retaining and Releasing a PDF Page

• CGPDFPageRetain
• CGPDFPageRelease

Getting the CFType ID

• CGPDFPageGetTypeID

Getting Page Information

• CGPDFPageGetBoxRect
• CGPDFPageGetDictionary
• CGPDFPageGetDocument
• CGPDFPageGetDrawingTransform
• CGPDFPageGetPageNumber
• CGPDFPageGetRotationAngle

Functions

CGPDFPageGetBoxRect

Returns the rectangle that represents a type of box for a content region or page dimensions of a PDF page.

CGRect CGPDFPageGetBoxRect (
   CGPDFPageRef page,
   CGPDFBox box
);

Parameters

page

A PDF page.

box

A CGPDFBox constant that specifies the type of box. For possible values, see “PDF Boxes”.

Discussion

Returns the rectangle associated with the specified box in the specified page. This is the value of the corresponding entry (such as /MediaBox, /ArtBox, and so on) in the page’s dictionary.

CGPDFPageGetDictionary

Returns the dictionary of a PDF page.

CGPDFDictionaryRef CGPDFPageGetDictionary (
   CGPDFPageRef page
);

Parameters

page

A PDF page.

CGPDFPageGetDocument

Returns the document for a page.

CGPDFDocumentRef CGPDFPageGetDocument (
   CGPDFPageRef page
);

Parameters

page

A PDF page.

CGPDFPageGetDrawingTransform

Returns the affine transform that maps a box to a given rectangle on a PDF page.

CGAffineTransform CGPDFPageGetDrawingTransform (
   CGPDFPageRef page,
   CGPDFBox box,
   CGRect rect,
   int rotate,
   bool preserveAspectRatio
);

Parameters

page

A PDF page.

box

A CGPDFBox constant that specifies the type of box. For possible values, see “PDF Boxes”.

rect

A Quartz rectangle.

rotate

An integer, that must be a multiple of 90, that specifies the angle by which the specified rectangle is rotated clockwise.

preserveAspectRatio

A Boolean value that specifies whether or not the aspect ratio should be preserved. A value of true specifies that the aspect ratio should be preserved.

Discussion

Quartz constructs the affine transform as follows:

• Computes the effective rectangle by intersecting the rectangle associated with box and the /MediaBox entry of the specified page.

• Rotates the effective rectangle according to the page’s /Rotate entry.

• Centers the resulting rectangle on rect. If the value of the rotate parameter is non-zero, then the rectangle is rotated clockwise by rotate degrees. The value of rotate must be a multiple of 90.

• Scales the rectangle, if necessary, so that it coincides with the edges of rect. If the value of preserveAspectRatio parameter is true, then the final rectangle coincides with the edges of rect only in the more restrictive dimension.

CGPDFPageGetPageNumber

Returns the page number of the specified PDF page.

size_t CGPDFPageGetPageNumber (
   CGPDFPageRef page
);

Parameters

page

A PDF page.

CGPDFPageGetRotationAngle

Returns the rotation angle of a PDF page.

int CGPDFPageGetRotationAngle (
   CGPDFPageRef page
);

Parameters

page

A PDF page.

CGPDFPageGetTypeID

Returns the CFType ID for PDF page objects.

CFTypeID CGPDFPageGetTypeID (
   void
);

CGPDFPageRelease

Decrements the retain count of a PDF page.

void CGPDFPageRelease (
   CGPDFPageRef page
);

Parameters

page

A PDF page.

Discussion

This function is equivalent to CFRelease, except that it does not cause an error if the page parameter is NULL.

CGPDFPageRetain

Increments the retain count of a PDF page.

CGPDFPageRef CGPDFPageRetain (
   CGPDFPageRef page
);

Parameters

page

A PDF page.

Discussion

This function is equivalent to CFRetain, except that it does not cause an error if the page parameter is NULL.

Data Types

CGPDFPageRef

An opaque type that represents a page in a PDF document.

typedef struct CGPDFPage *CGPDFPageRef;

Constants

PDF Boxes

Box types for a PDF page.

enum CGPDFBox {
   kCGPDFMediaBox = 0,
   kCGPDFCropBox = 1,
   kCGPDFBleedBox = 2,
   kCGPDFTrimBox = 3,
   kCGPDFArtBox = 4
};
typedef enum CGPDFBox CGPDFBox;

Constants

kCGPDFMediaBox

The page media box—a rectangle, expressed in default user space units, that defines the boundaries of the physical medium on which the page is intended to be displayed or printed

Available in Mac OS X v10.3 and later.

Declared in CGPDFPage.h.

kCGPDFCropBox

The page crop box—a rectangle, expressed in default user space units, that defines the visible region of default user space. When the page is displayed or printed, its contents are to be clipped to this rectangle.

Available in Mac OS X v10.3 and later.

Declared in CGPDFPage.h.

kCGPDFBleedBox

The page bleed box—a rectangle, expressed in default user space units, that defines the region to which the contents of the page should be clipped when output in a production environment

Available in Mac OS X v10.3 and later.

Declared in CGPDFPage.h.

kCGPDFTrimBox

The page trim box—a rectangle, expressed in default user space units, that defines the intended dimensions of the finished page after trimming.

Available in Mac OS X v10.3 and later.

Declared in CGPDFPage.h.

kCGPDFArtBox

The page art box—a rectangle, expressed in default user space units, defining the extent of the page’s meaningful content (including potential white space) as intended by the page’s creator.

Available in Mac OS X v10.3 and later.

Declared in CGPDFPage.h.

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