PDFlib 8 Windows COM/.NET Tutorial

7.3 Placing Images and imported PDF Pages
The function fit_image( ) for placing raster images and templates as well as fit_pdi_
page( ) for placing imported PDF pages offer a wealth of options for controlling the
placement on the page. This section demonstrates the most important options by looking
at some common application tasks. A complete list and descriptions of all options
can be found in the PDFlib API Reference.
Embedding raster images is easy to accomplish with PDFlib. The image file must first
be loaded with load_image( ). This function returns an image handle which can be used
along with positioning and scaling options in fit_image( ).
Embedding imported PDF pages works along the same line. The PDF page must be
opened with open_pdi_page( ) to retrieve a page handle for use in fit_pdi_page( ). The
same positioning and scaling options can be used as for raster images.
All samples in this section work the same for raster images, templates, and imported
PDF pages. Although code samples are only presented for raster images we talk about
placing objects in general. Before calling any of the fit functions a call to load_image( ) or
open_pdi_document( ) and open_pdi_page( ) must be issued. For the sake of simplicity
these calls are not reproduced here.
Cookbook Code samples regarding images and imported PDF pages can be found in the images and pdf_
import categories of the PDFlib Cookbook.
7.3.1 Simple Object Placement
Positioning an image at the reference point. By default, an object will be placed in its
original size with the lower left corner at the reference point. In this example we will
place an image with the bottom centered at the reference point. The following code
fragment places the image with the bottom centered at the reference point (0, 0).
p.fit_image(image, 0, 0, "position={center bottom}");
Similarly, you can use the position option with another combination of the keywords
left, right, center, top, and bottom to place the object at the reference point.
Placing an image with scaling.
modifying its size:
The following variation will place the image while
p.fit_image(image, 0, 0, "scale=0.5");
This code fragment places the object with its lower left corner at the point (0, 0) in the
user coordinate system. In addition, the object will be scaled in x and y direction by a
scaling factor of 0.5, which makes it appear at 50 percent of its original size.
Cookbook A full code sample can be found in the Cookbook topic images/starter_image.
7.3.2 Placing an Object in a Box
In order to position an object an additional box with specified width and height can be
used. Figure 7.2 shows the output of the examples described below. Note that the gray
box or line is depicted for visualizing the box size only ; it is not part of the actual output.
192 Chapter 7: Importing Images and PDF Pages (Edition for COM, .NET, and REALbasic)