Delphi Developer's Guide

Description

Delphi Developer's Guide provides a solution-oriented approach to application development that uses the visual programming tools in Delphi for implementation. Covers design methodology as well as the software. Shows what the future holds for GUI application development. Explains how visual programming is used in developing the various parts of an application. Title page Overview Contents Foreword Acknowledgments Introduction I. Getting started I.1. Windows Programming in Delphi A Little History What Is Delphi? The Delphi IDE The Code Generator Creating a Small Application What's So Great About Events, Anyway? Contract-Free Programming Turbo Prototyping Extensible Components Summary I.2. Moving to Pascal Commentary Variables Constants Typed Constants Operators Assignment Operator Comparison Operators Logical and, or, and not operators Arithmetic Operators Bitwise Operators Increment and Decrement Operators Types Strings Pascal Strings Null-Terminated Strings Arrays User-Defined Types Records Objects Pointers Typecasting Testing Conditions The if statement Using Case Statements Looping Constructs The while Loop The for Loop The repeat..until Loop The Break Procedure The Continue Procedure Procedures and Functions Passing Parameters Value Parameters Reference Parameters Constant Parameters Scope Units The uses Clause Circular Unit References Summary I.3. The Object Pascal Language What Does Object-Oriented Mean? Anatomy of an Object Object-Based Versus Object-Oriented A New Class Of Objects The Differences Between Class And Object PropertiesXXX Methods Defining Methods Method Types Overriding a Method Self Class Visibility Specifiers TObject: The Mother of Objects Getting a Handle on Exceptions Exception Classes The Exception object Raising an Exception Re-raising an Exception Runtime Type Information RTTI Methods RTTI Operators Summary I.4. The Visual Component Library (VCL) Types of Components TObject TPersistent TComponent TControl TWinControl TCustomControl TGraphicControl Other Components The Object Browser Summary I.5. Basic Concepts in Delphi—TForms, TScreen, and TApplication Strange New Life—Forms Changing a Form's Icon Boxes and Borders Making Forms Reusable Saving Your Form as a Template Adding a Context-Sensitive Help Form to the Template Setting Default Main and New Form in the Gallery Adding Forms to the Component Palette Creating Your Form Using Your Component The TScreen Component TApplication Summary I.6. Sprucing Up Forms Forms Versus Windows and Dialog Boxes Changing a Forms Appearance Through Its Properties A Form's Color and Size Choosing Two- or Three-Dimensional Forms Setting Fonts for Forms Adding Menus to a Project Creating a Main Menu Creating SpeedBars and Floating Toolbars Creating Fancy Dialog Boxes Using TStrings Adding Tabs to Your Applications Using Notebooks Adding Drag-and-Drop Capabilities Using Hints in Your Applications Summary I.7. Using VBX Controls with Delphi Understanding VBX Controls Deciding When To Use a VBX Adding a VBX to the Component Palette Using VBX Controls in Your Applications VBX Functions, Objects, and Types VBX Graphics VBX Helper Functions Shipping VBX-Equipped Applications Summary I.8. MDI Applications Creating the MDI Application Understanding MDI Basics Using the Child Forms The Text Editor Form The Bitmap Viewer Creating the MDI Frame Form Adding Menus to MDI Applications Creating the Menus Merging the Menus Working with Child Windows Creating a Child Edit Form at Runtime Closing Child Forms Using Window Commands Adding a List of Open Documents to the Menu Using Text Editor Commands Adding Common Dialog Boxes to Your MDI Application Opening Files Saving Your Files with the Text Editor Using the Font Dialog Box Using the Print Dialog Boxes Using the TPrinter Object Using the TPrintDialog Component Using the TPrinterSetup Dialog Printing Bitmaps Using the Clipboard Changing Child Styles Summary I.9. Understanding Messages What Is a Message? Types of Messages How the Windows Message System Works Delphi's Message System Message-Specific Records Handling Messages Message Handling: Not Contract-Free Assigning Message Result Values TApplication's OnMessage Event Sending Your Own Messages Perform() Send and Post Non-Standard Messages Notification Messages Internal VCL Messages User-Defined Messages Messages Within Your Application Messaging Between Applications Broadcasting Messages Anatomy of a Message System: VCL The Relationship Between Messages and Events Summary I.10. GDI and Graphics Programming Drawing with the Canvas Using Pens Using Brushes Using Fonts Using Canvas's Drawing Methods Drawing Lines Drawing Shapes Displaying Text with the Canvas Using Canvas' Pixels Delphi's Representation of Pictures: TImage Using GDI Functions Coordinate Systems and Mapping Modes Coordinate Systems Mapping Modes The Canvas Sample Project Advanced Fonts Types of Windows Fonts Basic Font Elements A Font's Typeface, Family, and Measurements GDI Font Categories Raster Fonts Explained Vector Fonts Explained True Type Fonts Explained Creating Your Own Fonts Creating the Font The TLOGFONT Structure Displaying Font Information Summary I.11. Writing Delphi Custom Components Deciding Whether to Write a Custom Component Writing Custom Components Creating a TRunButton Adding Code to the Skeleton Developing a Component Step One: Come Up with an Idea Step Two: Create a Game Plan Step Three: Write the Code Extending the TListBox Component The Idea and Game Plan The Code Creating a Marquee Analyzing How Your Component Will Work Writing the Component Using the Memory Canvas Using the Paint Method TMarquee's Timer Construction Ahead Creating Events The Four P's: Private, Protected, Public, and Published Virtual or Nonvirtual? Testing the Component Using the Component Creating a Component Palette Icon Summary I.12. Printing in Delphi The TPrinter Object TPrinter.Canvas Simple Printing Printing a TMemo Component Using BeginDoc() and EndDoc()—Printing a Bitmap Printing a Form Advanced Printing Printing a Columnar Report Aborting the Printing Process Printing Envelopes Printing in Abstract A Step-by-Step Process to Printing Getting Down to Business A Simple Print Preview Summary I.13. Multimedia Programming with Delphi Creating a Simple Media Player Using WAV Files in Your Applications Playing Video Showing the First Frame Using the Display Property Using the DisplayRect Property Unnderstanding TMediaPlayer Events Viewing the Source Code for EasyMM Examining Device Support Creating an Audio CD Player Displaying a Splash Screen Beginning the CD Player Updating the CD Player Information TimeFormat Time-Conversion Routines Methods for Updating the CD Player GetCDTotals() ShowCurrentTime() ShowTrackTime() CD Player Source Summary I.14. Sharing Information with the Clipboard and DDE In the Beginning, There Was the Clipboard Using the Clipboard with Text Using the Clipboard with Images Creating Your Own Clipboard Format Copying Data to the Clipboard Pasting Data from the Clipboard Flexible Applications Dynamic Data Exchange COmmunication Among Applications DDE Services DDE Topics DDE Items Breaking the Ice Creating a DDE Server Project Making the Data Available from a DDE Server Creating a DDE Client Project Establishing Links with a DDE Server Connecting Automatically with DDE Using the ddeAutomatic Connect Mode Connecting Manually with DDE Using the ddeManual Connect Mode Using the TDDEServerConv Component Poking Data Executing Macros Creating the Project Summary I.15. Object Linking and Embedding with OLE OLE Basics OLE Terminology What's So Great About OLE? OLE 1 Versus OLE 2 OLE 2 Behind the Scenes Component Object Model Structured Storage Uniform Data Transfer TOleContainer A Small Sample Application Embedding a new OLE Object Embedding or Linking an Existing OLE File A Bigger Sample Application Preparing for Clipboard Usage Creating a Child Form Saving to and Reading from Streams Using the Clipboard to Copy and Paste Summary I.16. Writing Database Applications The Borland Database Engine TDataset Navigating Datasets Opening a TDataset Navigating Records Bookmarks Navigational Example Loop Navigation Fields Field Names and Numbers Field Values Modifying and Adding Data Refreshing the Dataset Altered States Using TTable Searching FindKey() SetKey()..GotoKey() The Closest Match Which Index? Ranges SetRange() ApplyRange() Removing a Range Filter Search and Range Demo TTable Events Creating a Table TDataSource Calling the BDE Deploying Database Applications Summary I.17. Working with SQL and the TQuery Component What Is SQL? Set-Oriented Versus Record-Oriented Databases Using the TQuery Component Static SQL Statements Dynamic SQL Statements Using the Params Property Using the ParamByName Method Sorting the Data Using the Format() Function to Create SQL Strings Using TQuery's DataSource Property Inserting, Deleting, and Updating Records Inserting Records Deleting Records Updating Records Joining Multiple Tables Using Heterogeneous Queries Creating and Altering Tables Summary I.18. Dynamic Link Libraries (DLLs) What Exactly Is a DLL? Static Linking Versus Dynamic Linking Why Use DLLs? Sharing Code, Resources, and Data Hiding Implementation System-Level Routines Custom Controls Creating DLLs Counting Your Pennies (A Simple DLL) Creating the DLL Creating an Interface Unit Making Forms Available from DLLs Using DLLs in Your Delphi Applications Implicitly Loading DLLs Explicitly Loading a DLL Looking at DLL Initialization and Termination Code DLL Initialization DLL Termination Examining Special DLL Considerations Exceptions in Exported Functions Exceptions to Everything! Using the Borland Database Engine (BDE) in DLLs Other Considerations Calling C and C++ DLLs Calling Convention Name Mangling Variable Types You Make the Call Summary I.19. Migrating from Borland Pascal to Delphi Using the Result Variable Result: The Codebreaker Result: Not All Bad case Statements Working with PChars Error Handling Accessing Files Porting DOS Code Knowing Where to Begin Differences in Porting from Real Mode and Protected Mode Using Direct Memory Access Using Absolute Variables Handling Interrupts Making Interrupt Calls Linking in Assembly Modules Examining Overlays and Memory Issues Using the $M Directive Using DOS-Only Functions Using the Delay() Procedure Using the Exec() Procedure Using Halt() and RunError() Issues Regarding Object Model Versus Class Model TObject and Object Allocation The virtual Directive Streams Leaving OWL Behind Porting the User Interface Porting the Back End Looking at TList versus TCollection Summary I.20. Power Programming: BASM and DPMI Using BASM with Delphi How Does BASM Work? Easy Parameter Access var Parameters Using Extended Registers inline All-Assembly Procedures DOS Protected Mode Interface DPMI Memory Management More on Selectors Creating Selectors Using Precreated Selectors SelectorInc and Crossing Segment Boundaries Using TGodzillArray Interrupts Under DPMI Executing Supported Interrupts Executing Unsupported Interrupts More on DPMI Summary I.21. Hard-Core Windows Understanding the Application Window Procedure Subclassing Running Multiple Instances Preventing Multiple Instances Sharing Data Between Instances Using Windows Hooks Setting the Hook Using the Hook Function Using the Unhook Function Using SendKeys: a JournalPlayback Hook Deciding Whether To Use a JournalPlayback Hook Understanding how SendKeys Works Creating Key Presses Understanding the Interface Unit Using SendKeys() Subclassing Formas Making Nondirect TForm Descendants Child Windows Summary I.22. Testing and Debugging Common Program Bugs Using a Class Variable Before It Is Created Ensuring that Class Instances Are Freed Using the Uninitialized Pointer Using Uninitialized PChars Dereferencing the Nil Pointer Using the Integrated Debugger Using Command-Line Parameters Using Breakpoints Using Conditional Breakpoints Executing Code Line by Line Using the Watch Window Using the Evaluate and Modify Options Accessing the Call Stack Looking at Integrated Debugger Limitations Looking at the Turbo Debugger Features The CPU Window Breakpoints Breaking Logging Executing Using Group Enable and Disable Using Turbo Debugger Advanced User API (TDUSER) Looking at the Information in TTDUserInfoBlock Looking at Some Sample Uses for TDUSER API Using Turbo Debugger Video API (TVIDEO) Summary II. Real-World Building Blocks II.23. SysWatcher: A System Monitor Prototyping the User Interface Formatting Info Strings Getting System Information Determining Free Heap Getting the OS Version Getting Processor Information Getting Windows Directory Information Getting the DOS Environment Walking the Module List Using an Owner-Draw Listbox Finishing Touches Summary II.24. Building an Address Book Application Defining the Application Looking at the Feature List Defining the Data Creating the Main Form Connecting the Data-Aware Components Using the TDBLookupCombo Component Working with TField's EditMask Property Additional Components Adding the Menus to the AddrForm Getting to the Source Adding Clipboard Capabilities Summary II.25. Creating a Calendar/Scheduler and Alarm Application Examining the Calendar's Functionality Looking at the TDDGCaledar Class Creating the TDDGCalendar Looking at the Alarm Behavior Creating Alarm Events Defining the TOnAlarmEvent Working with the TINIFile Class Creating TDDGCalendar Drawing TDDGCalendar Using the Main Form Using the Day Scheduler Form Using the Set Alarm Form Using the Remove Alarm Form Summary II.26. Building a Phone Dialer/Terminal Application—Serial Communications Defining Serial Communications Serial Communication Considerations A TurboPower-ful Solution to Windows Serial-Communications Programming Installing Async Professional for Delphi Async Professional for Delphi, Unplugged The ComPort Component The TEmulator Component The TTerminal Component The TProtocol Component The TProtocolLog Component The TProtocolStatus Component The TModem Component The TModemDialer Component The APD Demonstration Project The Com Port Options Form The Protocol Options Form The DownloadDialog Form The UploadDialog Form The DialDialog Form The Main Form Running Through the Demo Summary II.27. Building a File Manager Application Examining the Feature List Creating the Necessary Forms The Main Form The Child Forms Prompt Forms Prompt1Form Prompt2Form The Find File Form The Properties Form Adding Functionality to the Forms Creating TStatusBar—A Custom Component Using the Main Form—TDDGFile Form Searching for Valid Drives Using Owner-Draw Comboboxes Exiting the Application Adding Functionality to TPrompt1Form Adding Functionality to TPrompt2Form Searching for Files Using Recursion Displaying File Properties and Version Information Defining the TVerInfoRes Class Getting File Attribute and Size Information Setting Up TDriveForm Executing Other Programs Copying Files Using Drag and Drop Capabilities Copying Files Through The Menu Moving and Renaming Files Deleting a File Creating and Removing Directories Searching for Files Exiting the Application Performing the Final Touches Summary II.28. Building a Time-Tracker Application Examining the Feature List Creating the Tables Looking at the Required Forms Creating MainForm Creating TaskManagerForm Working TField and Calculated Fields Creating AddTaskForm and SubTaskDataForm Creating ClientManForm Creating ReportForm Examining MainForm's Functionality Examining TaskManageForm's Functionality Examining ClientManForm's Functionality Examining ReportForm's Functionality Summary III. Real-World Applications III.29. Inventory Manager—Preliminary Design Issues The Concept The Data Model The Database Creating Domains Creating Tables The CUSTOMER Table The PART Table The SALE Table Using Generators Using Triggers Using Stored Procedures Granting Permissions Using the Data-Definition File Application Specification Summary III.30. Inventory Manager—User Interface Development The User Interface The Customer Information Page The Parts Information Page The Sales Information Page Linking to Data Connecting Switching Views Adding New Data New Part New Customer New Sale Searching Part Search Sale Search Customer Search Generating Reports Summary III.31. Inventory Manager—Finishing Touches Writing an Installation Program Writing Utility Routines Of Strings and PChars The Famous Backslash Waiting for Execution of Another Program Reading Environment Variables Copying a File Conversing with Program Manager Understanding the INI File [General] [SubDirs] [DiskX] [PMGroup] Creating the Install User Interface DirectoryForm OnCreate: Windows and System Directories Count the Files Check Your Paths Commence Copying Creating the SETUP Stub Looking at Other Ideas Creating the Inventory Manager Install Determining Which Files You Need Using the INI File Summary III.32. Personal Information Manager—Preliminary Design Issues Examining the PIM Feature List Creating the Main Form Creating the Calendar/Scheduler Page Creating the Note Taker Page Creating the Launch Pad Page Defining a TRunButton Summary III.33. Personal Information Manager—User Interface Development Printing a Calendar Adding the Note Taker Functionality with TFileStream Going Gently Down the Stream TStream THandleStream TFileStream TMemoryStream Using Streams Creating the Note Taker Classes Adding the Note Taker Classes to the PIM Adding Applications to the Launch Pad Summary III.34. Personal Information Manager—Finishing Touches Adding Help to Your Application Obtaining the Necessary Tools Looking at hte Elements of a Help System Help Topics Looking at the Help System Structure Using the PIM's Help System The Hierarchiy Making Help Part of the Application Adding the Help File Invoking Help Adding Context-Sensitive Help Summary Appendix A. Error Messages and Exceptions Layers of Handlers, Layers of Severity Runtime Errors DOS Errors I/O Errors Nonfatal Erorrs Fatal Errors File Modes Other Exceptions Index