Smalltalk and Object Orientation: an Introduction - Free

maintain a large number of images, then you can create file outs which will allow you to construct the
images you require, when you require them.
You can file out a whole class category, a class, a message protocol or a single method. This is done
by selecting “ file out ” from the right mouse button menu (middle mouse button on a three button
mouse) in the appropriate w indow from the System Browser (or one of the other available browsers,
e.g. the excellent Full Browser).
15.3.2 File in
Figure 15.2: The File List tool
If at a later stage you wish to “file in ” a “file out” file, you can do so using the file tool. This tool is
accessible from the VisualWorks Launcher by clicking on the filing cabinet icon. This presents the user
with a (very) basic file editor.
To view files, type into the top pane of the file editor th e appropriate path (if required) for your host
system, followed by either a specific name or a wild card.
The list of files will be displayed in the middle pane of the file tool. If you select any of these files,
their contents will be displayed in the bottom window. If the files are very large the system will ask you
whether you really want to see their contents or whether just information on the file (such as its size)
will do. You would use the right (or middle) mouse button to file in one of the files. If you do file it in,
then a trace of what is being loaded (and compiled) will be printed in the system Transcript window.
Once the load is completed, if it is successful you will be able to view it using the System Browser.
Note that if you have loaded in a whole class category, you will not be able to view it until you select
update in the category pane of any open browsers, or you open a new browser. Figure 15.2 illustrates
the file list tool being used to examine the contents of a file called Example.st. This file contains the
source of a simple example class.
If a file is selected and displayed in the bottom window, then you can edit that file and save the
changes you have made. You can also select part (or all) of t he file and then use the “do it” or “print it”
options to execute that selected code. This can be a very useful feature.
Note that you can also file in source code under programmatic control. To do this you need to send
the message fileIn to a file. For example:
'example.st' asFilename fileIn.
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