April 1998

What's new in C++Builder 3

C++Builder 3 is out, and it has plenty of new features to tempt you. In this article, we'll cover some of the most important new features. Many of them are borrowed from Delphi 3, but some are features that even Delphi doesn't have yet. (You've probably already noticed that the version following C++Builder 1 is C++Builder 3. Borland did this to synchronize C++Builder's version number with that of Delphi.)

Project groups

The new Project Manager

The Project Manager has the usual features you'd expect, such as the ability to add files to projects or remove them. We can't discuss all its new capabilities here, but once you try it, you'll quickly see how great an improvement it is over C++Builder 1.

C++Builder packages

You can build programs written with C++Builder 3 to use packages or not use them. If you don't use packages (the default), then your applications will be just as they were in C++Builder 1. In other words, the code needed for your application to run is linked into your application's EXE file. If you choose to use packages, then your application will be much smaller--but you'll have to ship the runtime packages with your application (which can easily amount to 3MB or more). If you previously used Borland C++, then you'll recognize this as the old static linking versus dynamic linking scenario.

New Code Editor features

Code templates are another nice feature of the Code Editor. Code templates let you quickly and easily insert prewritten sections of code into your programs. When you want to insert a code template, you first press [Ctrl]J. A list box containing the available code templates pops up, as shown in Figure A. Once you've selected a code template, the text for that template is inserted into your application at the cursor location. You can then fill in the gaps and add additional code as needed.

Figure A: This list box contains the available code templates.

C++Builder 3 comes with a number of code templates ready for you to use. For example, most of the typical C++ language features such as the for loop, the while loop, the switch statement, and a typical class declaration are predefined. The great thing about code templates is that you can add your own to those provided by C++Builder. You add code templates through the Code Insight page of the Environment Options dialog box or by directly editing the BCB.DCI file (found in the BIN directory).

Another new feature of the Code Editor is tool-tip expression evaluation. (This is really a feature of the debugger, but you use it when stepping through code in the Code Editor.) When your program pauses at a breakpoint, you can place your mouse pointer over a variable, and a tool tip will appear showing that variable's value. If you're a Borland C++ 5.0 user, you probably use this feature frequently. Figure B shows the tool-tip expression evaluator in action.

Figure B: Tool-tip expression evaluation is a new debugger feature.

The Code Editor now has a visible gutter along the left edge of the editor window, as you can see in Figure B. This feature makes it much easier to detect the gutter and avoid it when editing code (I always found myself inadvertently setting a breakpoint when trying to click on the first column in the Code Editor). You can change the width of the gutter or hide it altogether. The gutter contains glyphs that indicate lines for which code is generated, a breakpoint, or the current execution point.

Find In Files

Debugger enhancements

Speaking of the Debug Inspector, it's mostly unchanged from the first version of C++Builder. However, there's one important new IDE feature that affects the Debug Inspector: The Debugging page of the Environment Options dialog box contains an Inspectors Stay On Top check box. When this option is on, all Debug Inspector windows will stay on top of the Code Editor window. This is a very welcome feature, since most of the time you want your Debug Inspector windows on top of the Code Editor. The Watch Window also has some improvements. Most noticeably, when you add a watch, C++Builder immediately adds to the Watch Window the variable to watch, without first displaying the Watch Properties dialog box. In C++Builder 1, the Watch Properties dialog box appears first, forcing you to click OK or press [Enter]. This one-step process is a welcome improvement.

Another feature of the Watch Window is the ability to set a variable breakpoint. You can add a variable to the Watch Window and then choose Break When Changed from the Watch Window speed menu. When that variable changes value, the debugger will pause program execution as if it had hit a breakpoint.

The Event Log--another new feature of the IDE and the debugger--replaces and augments the OutDbg1.txt file from C++Builder 1. It shows status messages for the modules your program loads, when your program starts and stops, when the program hits a breakpoint, and other information. To send your own messages to the Event Log, use the Windows API function OutputDebugString(). You can save the messages in the Event Log to a file, if you wish.

As I alluded to earlier, the Environment Options dialog box has a new Debugging page. This page lets you set some new options for the debugger and the Event Log. More importantly, the page contains settings that determine how exceptions are handled under the debugger. You'll have to spend some time with the debugger to really appreciate this feature.

The debugger now lets you start a host application when debugging a DLL. This is an indispensable feature when you're writing a DLL that will be called from non-C++Builder applications. To specify a host application, you choose Run | Parameters from the main menu and type an EXE name in the Host Application field of the Run Parameters dialog box. When you click the Load button, the host application will load; you can then debug your DLL as usual. The C++Builder IDE also has a new utility called the Modules window, which you invoke by choosing View | Modules from the main menu. This window shows the modules that are currently loaded and the entry points (functions) of each module. When you double-click on an entry point, the Code Editor will take you to the source line containing that entry point (or the CPU view if no source code exists for the entry point). This is one of those options that is probably of interest primarily to power users.

Component templates

New components

Additional

TChart is a major new native VCL component (unlike the TVtChart ActiveX control) that makes charting easy. Be sure to look into TChart.

Win32

The two most significant components on the Win32 tab are TToolbar and TCoolbar. The TToolbar component lets you create a toolbar on which all the components (buttons, combo boxes, and so on) are automatically a uniform height. TCoolbar is a container component used primarily as a holder for TToolbars. You can arrange the bands (usually toolbars) on a TCoolbar and size them horizontally with sizing grips on the left side of the band. The Toolbar and Coolbar components take some time to figure out, but once you get the hang of how they work, they're very flexible.

Internet

Database Components

The Client/Server version of C++Builder 3 contains an additional tab--Decision Cube. This tab's six components provide advanced data analysis. The QReport tab also has some new database-related components you'll want to examine.

Dialogs

New language features

Another extension allows dynamic functions in classes derived from TObject. A dynamic function is similar to a virtual function. The difference is that a dynamic function occupies space in the virtual table only in classes that define the function. A virtual function occupies space in every derived class, regardless of whether that class defines the virtual function. Dynamic functions make for smaller executables--but at the expense of execution speed--since the virtual tables of all derived classes are searched each time a dynamic function is called. The __declspec keyword has been expanded to take the dynamic parameter, as follows:

void __declspec(dynamic) MyFunction();