Delphi for Beginners

What is Borland Delphi?
Borland Delphi is a sophisticated Windows programming environment, suitable for beginners and professional programmers alike. Using Delphi you can easily create self-contained, user friendly, highly efficient Windows applications in a very short time - with a minimum of manual coding.

Delphi provides all the tools you need to develop, test and deploy Windows applications, including a large number of so-called reusable components.
Borland Delphi, in it's latest version, provides a cross platform solution when used with Borland Kylix - Borland's RAD tool for the Linux platform.

Delphi's roots lie in Borland's Turbo Pascal, introduced in the mid-1980s. Object Pascal, the object-oriented extensions to Pascal, is the underlying language of Delphi. The Visual Component Library, or VCL, is a hierarchy of Object Pascal objects that allow you to design applications. A better way of describing Delphi is an Object Pascal-based visual development environment.

Delphi editions
The latest version of Delphi (in the moment of writing this chapter), version 6, comes in three different editions:

* Delphi Personal - makes learning to develop non-commercial Windows applications fast and fun. Delphi 6 Personal makes learning Windows development easy with drag-and-drop visual programming.
* Delphi Professional - adds the tools necessary to create applications with the latest Windows® ME/2000 look-and-feel. Dramatically enhance functionality with minimal code using the power and flexibility of SOAP and XML to easily integrate Web Services into client-side applications.
* Delphi Enterprise - includes additional tools, extensive options for Internet. Delphi 6 makes next-generation e-business development with Web Services a snap.

The Delphi IDE
As explained in the first chapter of this course, one of the ways to start Delphi is to choose Programs | Borland Delphi 6 | Delphi 6 from the Windows Start menu.

When Delphi starts (it could even take one full minute to start - depending on your hardware performance) you are presented with the IDE: the user interface where you can design, compile and debug your Delphi projects.

The Delphi IDE

Like most other development tools (and unlike other Windows applications), Delphi IDE comprises a number of separate windows.

The menus, toolbars
The menus, toolbars and the Component Palette
The main window, positioned on the top of the screen, contains the main menu, toolbar and Component palette. The title bar of the main window contains the name of the current project (you'll see in some of the future chapters what exactly is a Delphi project). The menu bar includes a dozen drop-down menus - we'll explain many of the options in these menus later through this course. The toolbar provides a number of shortcuts to most frequently used operations and commands - such as running a project, or adding a new form to a project. To find out what particular button does, point your mouse "over" the button and wait for the tooltip. As you can see from the tooltip (for example, point to [Toggle Form/Unit]), many toolbuttons have keyboard shortcuts ([F12]).
The menus and toolbars are freely customizable. I suggest you to leave the default arrangement while working through the chapters of this course.

The Component Palette

You are probably familiar with the fact that any window in a standard Windows application contains a number of different (visible or not to the end user) objects, like: buttons, text boxes, radio buttons, check boxes etc. In Delphi programming terminology such objects are called controls (or components). Components are the building blocks of every Delphi application. To place a component on a window you drag it from the component palette. Each component has specific attributes that enable you to control your application at design and run time.

Depending on the version of Delphi (assumed Delphi 6 Personal through this course), you start with more than 85 components at your disposal - you can even add more components later (those that you create or from a third party component vendor).

The components on the Component Palette are grouped according to the function they perform. Each page tab in the Component palette displays a group of icons representing the components you can use to design your application interface. For example, the Standard and Additional pages include controls such as an edit box, a button or a scroll box.

To see all components on a particular page (for example on the Win32 page) you simply click the tab name on the top of the palette. If a component palette lists more components that can be displayed on a page an arrow will appear on a far right side of the page allowing you to click it to scroll right. If a component palette has more tabs (pages) that can be displayed, more tabs can be displayed by clicking on the arrow buttons on the right-hand side.

Form1 window

Each time you start Delphi, a new project is created that consists of one *empty* window. A typical Delphi application, in most cases, will contain more than one window - those windows are referred to as forms. In our case this form has a name, it is called Form1. This form can be renamed, resized and moved, it has a caption and the three standard minimize, maximize and close buttons. As you can see a Delphi form is a regular Windows window.

Unit1.pas - the Code Editor window
Code Editor window
If the Form1 is the active window and you press [F12], the Code Editor window will be placed on top. As you design user interface of your application, Delphi automatically generates the underlying Object Pascal code. More lines will be added to this window as you add your own code that drives your application. This window displays code for the current form (Form1); the text is stored in a (so-called) unit - Unit1. You can open multiple files in the Code Editor. Each file opens on a new page of the Code editor, and each page is represented by a tab at the top of the window.

The Object Inspector
The Object Inspector Each component and each form, has a set of properties - such as color, size, position, caption - that can be modified in the Delphi IDE or in your code, and a collection of events - such as a mouse click, keypress, or component activation - for which you can specify some additional behavior. The Object Inspector displays the properties and events (note the two tabs) for the selected component and allows you to change the property value or select the response to some event.

For example, each form has a Caption (the text that appears on it's title bar). To change the caption of Form1 first activate the form by clicking on it. In the Object Inspector find the property Caption (in the left column), note that it has the 'Form1' value (in the right column). To change the caption of the form simply type the new text value, like 'My Form' (without the single quotes). When you press [Enter] the caption of the form will change to My Form.
Note that some properties can be changed more simply, the position of the form on the screen can be set by entering the value for the Left and Top properties - or the form can be simply dragged to the desired location.

The Object TreeView
Above the Object Inspector you should see the Object TreeView window. For the moment it's display is pretty simple. As you add components to the form, you'll see that it displays a component's parent-child relationships in a tree diagram. One of the great features of the Object TreeView is the ability to drag and drop components in order to change a component container without losing connections with other components.

The Object TreeView, Object Inspector and the Form Designer (the Form1 window) work cooperatively. If you have an object on a form (we have not placed any yet) and click it, its properties and events are displayed in the Object Inspector and the component becomes focussed in the Object TreeView.

Closing Delphi
To stop working in the Delphi IDE, you can point to the File | Exit option in the main menu. If you have made changes to the current project, you'll be asked if you want to save the changes. Since this is the first time we've done some changes to the project in this course, and we do not yet know how a project is saved and what are the options, select [No].