Qk1 and its form Form1 (an instance of TForm1, descendent of TQkForm, descendant of the standard Delphi class TForm), kick off initializing QuArK - TForm1 is the main window; its Create method FormCreate (the OnCreate event handler for a TForm1, as you can see by looking in Qk1.dfm, the which defines the setup of a TForm1) initializes Python, sets up the main explorer window, and heaps of other things. Read the Delphi help on OnCreate.

The handlers for the various Main Menu items are all there (opening/saving files, cut/paste in the tree-view), tho you should not have to mess with any of this stuff in order to support a new file-type for example (you do that by defining a subclass of QkFileObject and redefining methods, as discussed in the 'QFileObjects').

The Toolbars containing the main menus at the left and right of the main window are set up in Form1 itself, defined in Qk1.dfm, also the menus. The buttons are defined in defaults.qrk, in Tool bars|Main.toolbar, which is put into the topdock control by the line:

 RestorePositionTb('Main', False, Explorer);

in Tform1.FormCreate (QkForm.pas). Lines of this form can be used to put additional button toolbars into the main window (with names other then 'Main').

The actions of the buttons are defined by their cmd:macro values; the msg specifies of these become the cmd parameter to the method TQkForm.MacroCommand (QkForm.pas).

For those who aren't really up on how Delphi programs work, TForm1 is fired up by the QuArK.dpr file, which you can look at in Pascal Source form by opening up the project manager, then RMB|View Source on the QuArK.exe item (from which all the various modules hang as dependents). Or in fact you can just look at it with a text editor. You'll see a long list of 'uses' statements, followed by a few lines of the kind of code that's normally used to fire up GUI applications built with class libraries.

The line:

 Application.CreateForm(TForm1, Form1);

is responsible for setting up everything that distinguishes QuArK from other Delphi applications (with the uses statement marshalling the resources).

(What else should we know about Qk1?)

The 'idle job' is what runs when the application is idle, i.e. has nothing else to do. Qk1.pas defines general methods to register new idle jobs, which will be performed step-by-step -- every time the application is idle, a little bit of the job is performed (through the AppIdle method). This is only used for the texture browser, whose idle job consists of filling the texture pages (in QkWad.pas), one texture at a time. This is done as an idle job so that it can be interrupted by the user. I found it more convenient to do it like this instead of starting a new thread that would load textures in parallel with normal program execution, mainly because there are a number of issues with multiple threads accessing the same internal data at the same time.