| Top | Home | Up | Prev | Next |
PDF Surfaces — Rendering PDF documents
The PDF surface is used to render cairo graphics to Adobe PDF files and is a multi-page vector surface backend.
The following mime types are supported on source patterns:
CAIRO_MIME_TYPE_JPEG, CAIRO_MIME_TYPE_JP2,
CAIRO_MIME_TYPE_UNIQUE_ID, CAIRO_MIME_TYPE_JBIG2,
CAIRO_MIME_TYPE_JBIG2_GLOBAL, CAIRO_MIME_TYPE_JBIG2_GLOBAL_ID,
CAIRO_MIME_TYPE_CCITT_FAX, CAIRO_MIME_TYPE_CCITT_FAX_PARAMS.
JBIG2 data in PDF must be in the embedded format as described in
ISO/IEC 11544. Image specific JBIG2 data must be in
CAIRO_MIME_TYPE_JBIG2. Any global segments in the JBIG2 data
(segments with page association field set to 0) must be in
CAIRO_MIME_TYPE_JBIG2_GLOBAL. The global data may be shared by
multiple images. All images sharing the same global data must set
CAIRO_MIME_TYPE_JBIG2_GLOBAL_ID to a unique identifier. At least
one of the images must provide the global data using
CAIRO_MIME_TYPE_JBIG2_GLOBAL. The global data will only be
embedded once and shared by all JBIG2 images with the same
CAIRO_MIME_TYPE_JBIG2_GLOBAL_ID.
The CAIRO_MIME_TYPE_CCITT_FAX mime data requires a number of decoding
parameters These parameters are specified using CAIRO_MIME_TYPE_CCITT_FAX_PARAMS.
CAIRO_MIME_TYPE_CCITT_FAX_PARAMS mime data must contain a string of the form
"param1=value1 param2=value2 ...".
Columns
: [required] An integer specifying the width of the image in pixels.
Rows
: [required] An integer specifying the height of the image in scan lines.
K
: [optional] An integer identifying the encoding scheme used. < 0
is 2 dimensional Group 4, = 0 is Group3 1 dimensional, > 0 is mixed 1
and 2 dimensional encoding. Default is 0.
EndOfLine
: [optional] If true end-of-line bit patterns are present. Default is false.
EncodedByteAlign
: [optional] If true the end of line is padded
with 0 bits so the next line begins on a byte boundary. Default is false.
EndOfBlock
: [optional] If true the data contains an end-of-block pattern. Default is true.
BlackIs1
: [optional] If true 1 bits are black pixels. Default is false.
DamagedRowsBeforeError
: [optional] An integer specifying the
number of damages rows tolerated before an error occurs. Default is 0.
Boolean values may be "true" or "false", or 1 or 0.
These parameters are the same as the CCITTFaxDecode parameters in the PostScript Language Reference and Portable Document Format (PDF). Refer to these documents for further details.
An example CAIRO_MIME_TYPE_CCITT_FAX_PARAMS string is:
"Columns=10230 Rows=40000 K=1 EndOfLine=true EncodedByteAlign=1 BlackIs1=false"
cairo_surface_t * cairo_pdf_surface_create (const char *filename,double width_in_points,double height_in_points);
Creates a PDF surface of the specified size in points to be written
to filename
.
filename
a filename for the PDF output (must be writable), NULL may be
used to specify no output. This will generate a PDF surface that
may be queried and used as a source, without generating a
temporary file.
width_in_points
width of the surface, in points (1 point == 1/72.0 inch)
height_in_points
height of the surface, in points (1 point == 1/72.0 inch)
a pointer to the newly created surface. The caller
owns the surface and should call cairo_surface_destroy() when done
with it.
This function always returns a valid pointer, but it will return a
pointer to a "nil" surface if an error such as out of memory
occurs. You can use cairo_surface_status() to check for this.
Since: 1.2
cairo_surface_t * cairo_pdf_surface_create_for_stream (cairo_write_func_t write_func,void *closure,double width_in_points,double height_in_points);
Creates a PDF surface of the specified size in points to be written
incrementally to the stream represented by write_func
and closure
.
write_func
a cairo_write_func_t to accept the output data, may be NULL
to indicate a no-op write_func
. With a no-op write_func
,
the surface may be queried or used as a source without
generating any temporary files.
closure
the closure argument for write_func
width_in_points
width of the surface, in points (1 point == 1/72.0 inch)
height_in_points
height of the surface, in points (1 point == 1/72.0 inch)
a pointer to the newly created surface. The caller
owns the surface and should call cairo_surface_destroy() when done
with it.
This function always returns a valid pointer, but it will return a
pointer to a "nil" surface if an error such as out of memory
occurs. You can use cairo_surface_status() to check for this.
Since: 1.2
void cairo_pdf_surface_restrict_to_version (cairo_surface_t *surface,cairo_pdf_version_t version);
Restricts the generated PDF file to version
. See cairo_pdf_get_versions()
for a list of available version values that can be used here.
This function should only be called before any drawing operations have been performed on the given surface. The simplest way to do this is to call this function immediately after creating the surface.
Since: 1.10
void cairo_pdf_get_versions (cairo_pdf_version_t const **versions,int *num_versions);
Used to retrieve the list of supported versions. See
cairo_pdf_surface_restrict_to_version().
versions
supported version list
num_versions
list length
Since: 1.10
const char *
cairo_pdf_version_to_string (cairo_pdf_version_t version);
Get the string representation of the given version
id. This function
will return NULL if version
isn't valid. See cairo_pdf_get_versions()
for a way to get the list of valid version ids.
version
a version id
the string associated to given version.
Since: 1.10
void cairo_pdf_surface_set_size (cairo_surface_t *surface,double width_in_points,double height_in_points);
Changes the size of a PDF surface for the current (and subsequent) pages.
This function should only be called before any drawing operations
have been performed on the current page. The simplest way to do
this is to call this function immediately after creating the
surface or immediately after completing a page with either
cairo_show_page() or cairo_copy_page().
surface
a PDF cairo_surface_t
width_in_points
new surface width, in points (1 point == 1/72.0 inch)
height_in_points
new surface height, in points (1 point == 1/72.0 inch)
Since: 1.2
int cairo_pdf_surface_add_outline (cairo_surface_t *surface,int parent_id,const char *utf8,const char *link_attribs,cairo_pdf_outline_flags_t flags);
Add an item to the document outline hierarchy with the name utf8
that links to the location specified by link_attribs
. Link
attributes have the same keys and values as the Link Tag,
excluding the "rect" attribute. The item will be a child of the
item with id parent_id
. Use CAIRO_PDF_OUTLINE_ROOT as the parent
id of top level items.
surface
a PDF cairo_surface_t
parent_id
the id of the parent item or CAIRO_PDF_OUTLINE_ROOT if this is a top level item.
utf8
the name of the outline
link_attribs
the link attributes specifying where this outline links to
flags
outline item flags
the id for the added item.
Since: 1.16
void cairo_pdf_surface_set_metadata (cairo_surface_t *surface,cairo_pdf_metadata_t metadata,const char *utf8);
Set document metadata. The CAIRO_PDF_METADATA_CREATE_DATE and
CAIRO_PDF_METADATA_MOD_DATE values must be in ISO-8601 format:
YYYY-MM-DDThh:mm:ss. An optional timezone of the form "[+/-]hh:mm"
or "Z" for UTC time can be appended. All other metadata values can be any UTF-8
string.
For example:
1 2
cairo_pdf_surface_set_metadata(surface,CAIRO_PDF_METADATA_TITLE,"My Document"); cairo_pdf_surface_set_metadata(surface,CAIRO_PDF_METADATA_CREATE_DATE,"2015年12月31日T23:59+02:00");
Since: 1.16
void cairo_pdf_surface_set_custom_metadata (cairo_surface_t *surface,const char *name,const char *value);
Set custom document metadata. name
may be any string except for
the following names reserved by PDF: "Title", "Author", "Subject",
"Keywords", "Creator", "Producer", "CreationDate", "ModDate",
"Trapped".
If value
is NULL or an empty string, the name
metadata will not be set.
For example:
1
cairo_pdf_surface_set_custom_metadata(surface,"ISBN","978-0123456789");
surface
a PDF cairo_surface_t
name
The name of the custom metadata item to set (utf8).
value
The value of the metadata (utf8).
Since: 1.18
void cairo_pdf_surface_set_page_label (cairo_surface_t *surface,const char *utf8);
Set page label for the current page.
Since: 1.16
void cairo_pdf_surface_set_thumbnail_size (cairo_surface_t *surface,int width,int height);
Set the thumbnail image size for the current and all subsequent pages. Setting a width or height of 0 disables thumbnails for the current and subsequent pages.
Since: 1.16
#define CAIRO_HAS_PDF_SURFACE
Defined if the PDF surface backend is available. This macro can be used to conditionally compile backend-specific code.
Since: 1.2
#define CAIRO_PDF_OUTLINE_ROOT 0
The root outline item in cairo_pdf_surface_add_outline().
Since: 1.16
cairo_pdf_outline_flags_t is used by the
cairo_pdf_surface_add_outline() function specify the attributes of
an outline item. These flags may be bitwise-or'd to produce any
combination of flags.
CAIRO_PDF_OUTLINE_FLAG_OPEN
The outline item defaults to open in the PDF viewer (Since 1.16)
CAIRO_PDF_OUTLINE_FLAG_BOLD
The outline item is displayed by the viewer in bold text (Since 1.16)
CAIRO_PDF_OUTLINE_FLAG_ITALIC
The outline item is displayed by the viewer in italic text (Since 1.16)
Since: 1.16
cairo_pdf_metadata_t is used by the
cairo_pdf_surface_set_metadata() function specify the metadata to set.
CAIRO_PDF_METADATA_TITLE
The document title (Since 1.16)
CAIRO_PDF_METADATA_AUTHOR
The document author (Since 1.16)
CAIRO_PDF_METADATA_SUBJECT
The document subject (Since 1.16)
CAIRO_PDF_METADATA_KEYWORDS
The document keywords (Since 1.16)
CAIRO_PDF_METADATA_CREATOR
The document creator (Since 1.16)
CAIRO_PDF_METADATA_CREATE_DATE
The document creation date (Since 1.16)
CAIRO_PDF_METADATA_MOD_DATE
The document modification date (Since 1.16)
Since: 1.16
cairo_pdf_version_t is used to describe the version number of the PDF specification that a generated PDF file will conform to.
CAIRO_PDF_VERSION_1_4
The version 1.4 of the PDF specification. (Since 1.10)
CAIRO_PDF_VERSION_1_5
The version 1.5 of the PDF specification. (Since 1.10)
CAIRO_PDF_VERSION_1_6
The version 1.6 of the PDF specification. (Since 1.18)
CAIRO_PDF_VERSION_1_7
The version 1.7 of the PDF specification. (Since 1.18)
Since: 1.10