Smalltalk and modern graphical interfaces were developed together. Even before the first public release of Smalltalk in 1983, Smalltalk had a self-hosting graphical development environment, and all Smalltalk development was taking place in it. Lets start by looking at the main tools in Squeak, all of which can be dragged out of the Tools flap in the SqueakByExample.org image (see Section 1.1). Depending on your personal settings, the Tools flap can be opened by mousing over or clicking on the orange tab on the right-hand edge of Squeak’s main window.
- The Browser is the central development tool. You will use it to create, define, and organize your classes and methods. Using it you can also navigate through all the library classes: unlike other environments where the source code is stored in separate files, in Smalltalk all classes and methods are contained in the image.
- The Message Names tool is used to look at all of the methods with a particular selector, or with a selector containing a substring.
- The Method Finder tool will also let you find methods, but according to what they do as well as what they are called.
- The Monticello Browser is the starting point for loading code from, and saving code in, Monticello packages.
- The Process Browser provides a view on all of the processes (threads) executing in Smalltalk.
- The Test Runner lets you run and debug SUnit tests, and is described in Chapter 7.
- The Transcript is a window on the
Transcriptoutput stream, which is useful for writing log messages and has already been described in Section 1.4.
- The Workspace is a window into which you can type input. It can be used for any purpose, but is most often used for typing Smalltalk expressions and executing them as
do its. The use of the workspace was also illustrated in Section 1.4.
The Debugger has an obvious role, but you will discover that it has a more central place compared to debuggers for other programming languages, because in Smalltalk you can program in the debugger. The debugger is not launched from a menu or from the Tools flap; it is normally entered by running a failing test, by typing CMD–. to interrupt a running process, or by inserting a
self halt expression in code.