PDFlib 8 Windows COM/.NET Tutorial

Fig. 7.8
Adjusting the page
size. Left to right:
exact, enlarge,
shrink
7.3.5 Adjusting the Page Size
Adjusting the page size to an image. In the next example we will automatically adjust
the page size to the object’s size. This can be useful, for example, for archiving images in
the PDF format. The reference point (x, y) can be used to specify whether the page will
have exactly the object’s size, or somewhat larger or smaller. When enlarging the page
size (see Figure 7.8) some border will be kept around the image. If the page size is smaller
than the image some parts of the image will be clipped. Let’s start with exactly matching
the page size to the object’s size:
p.fit_image(image, 0, 0, "adjustpage");
The next code fragment increases the page size by 40 units in x and y direction, creating
a white border around the object:
p.fit_image(image, 40, 40, "adjustpage");
The next code fragment decreases the page size by 40 units in x and y direction. The object
will be clipped at the page borders, and some area within the object (with a width of
40 units) will be invisible:
p.fit_image(image, -40, -40, "adjustpage");
In addition to placing by means of x and y coordinates (which specify the object’s distance
from the page edges, or the coordinate axes in the general case) you can also specify
a target box. This is a rectangular area in which the object will be placed subject to
various formatting rules. These can be controlled with the boxsize, fitmethod and
position options.
Cloning the page boxes of an imported PDF page. You can copy all relevant page boxes
(MediaBox, CropBox) etc. of an imported PDF page to the current output page. The
cloneboxes option must be supplied to open_pdi_page( ) to read all relevant box values,
and again in fit_pdi_page( ) to apply the box values to the current page:
/* Open the page and clone the page box entries */
inpage = p.open_pdi_page(indoc, 1, "cloneboxes");
...
/* Start the output page with a dummy page size */
p.begin_page_ext(10, 10, "");
...
/*
* Place the imported page on the output page, and clone all
* page boxes which are present in the input page; this will
* override the dummy size used in begin_page_ext().
*/
p.fit_pdi_page(inpage, 0, 0, "cloneboxes");
7.3 Placing Images and imported PDF Pages 197