Delphi 6 for Windows Developer’s Guide

1108 Pages·2001·5.324 MB·english

by  Borland

Developer’s Guide
Borland®
Delphi™ 6
for Windows
Borland Software Corporation
100 Enterprise Way, Scotts Valley, CA 95066-3249
COPYRIGHT © 1983, 2001 Borland Software Corporation
Printed in the U.S.A.
Contents
Chapter 1 TPersistent branch. . . . . . . . . . . . . . . 3-14
Introduction 1-1 TComponent branch . . . . . . . . . . . . . 3-15
TControl branch. . . . . . . . . . . . . . . . 3-16
What’s in this manual? . . . . . . . . . . . . . . 1-1
TWinControl/TWidgetControl branch . . . 3-17
Manual conventions. . . . . . . . . . . . . . . . 1-3
Properties common to TControl . . . . . . . 3-18
Developer support services. . . . . . . . . . . . 1-3
Action properties . . . . . . . . . . . . . 3-18
Ordering printed documentation . . . . . . . . 1-3
Position, size, and alignment
Part I properties . . . . . . . . . . . . . . . . . 3-19
Programming with Delphi Display properties . . . . . . . . . . . . . 3-19
Parent properties. . . . . . . . . . . . . . 3-19
A navigation property. . . . . . . . . . . 3-19
Chapter 2
Drag-and-drop properties . . . . . . . . 3-20
Developing applications with Delphi 2-1
Drag-and-dock properties
Integrated development environment. . . . . . 2-1 (VCL only) . . . . . . . . . . . . . . . . 3-20
Designing applications . . . . . . . . . . . . . . 2-2 Standard events common to TControl . . . 3-20
Developing applications . . . . . . . . . . . . . 2-3 Properties common to TWinControl and
Creating projects . . . . . . . . . . . . . . . . 2-3 TWidgetControl . . . . . . . . . . . . . . . 3-21
Editing code. . . . . . . . . . . . . . . . . . . 2-4 General information properties . . . . . 3-21
Compiling applications . . . . . . . . . . . . 2-4 Border style display properties. . . . . . 3-22
Debugging applications . . . . . . . . . . . . 2-5 Navigation properties. . . . . . . . . . . 3-22
Deploying applications . . . . . . . . . . . . 2-5 Drag-and-dock properties
(VCL only) . . . . . . . . . . . . . . . . 3-22
Chapter 3 Events common to TWinControl and
Using the component libraries 3-1 TWidgetControl . . . . . . . . . . . . . . . 3-22
Understanding the component libraries. . . . . 3-1 Creating the application user interface . . . 3-23
Properties, methods, and events . . . . . . . 3-2 Using Delphi components . . . . . . . . . . 3-23
Properties . . . . . . . . . . . . . . . . . . 3-2 Setting component properties . . . . . . . . 3-24
Methods . . . . . . . . . . . . . . . . . . . 3-3 Using the Object Inspector . . . . . . . . 3-24
Events . . . . . . . . . . . . . . . . . . . . 3-3 Using property editors . . . . . . . . . . 3-25
User events . . . . . . . . . . . . . . . . . 3-3 Setting properties at runtime. . . . . . . 3-25
System events . . . . . . . . . . . . . . . . 3-4 Calling methods. . . . . . . . . . . . . . . . 3-25
Object Pascal and the class libraries . . . . . . . 3-4 Working with events and event
Using the object model . . . . . . . . . . . . 3-4 handlers. . . . . . . . . . . . . . . . . . . . 3-25
What is an object?. . . . . . . . . . . . . . 3-5 Generating a new event handler. . . . . 3-26
Examining a Delphi object. . . . . . . . . 3-5 Generating a handler for a component’s
Changing the name of a component . . . 3-7 default event . . . . . . . . . . . . . . . 3-26
Inheriting data and code from an object. . . 3-8 Locating event handlers. . . . . . . . . . 3-26
Scope and qualifiers . . . . . . . . . . . . . . 3-8 Associating an event with an existing
Private, protected, public, and published event handler. . . . . . . . . . . . . . . 3-27
declarations . . . . . . . . . . . . . . . . 3-9 Associating menu events with event
Using object variables . . . . . . . . . . . . .3-10 handlers. . . . . . . . . . . . . . . . . . 3-28
Creating, instantiating, and destroying Deleting event handlers. . . . . . . . . . 3-28
objects . . . . . . . . . . . . . . . . . . . . .3-11 VCL and CLX components . . . . . . . . . . . 3-28
Components and ownership . . . . . . . . .3-11 Adding custom components to the
Objects, components, and controls. . . . . . . .3-12 Component palette . . . . . . . . . . . . . 3-30
TObject branch . . . . . . . . . . . . . . . . .3-14 Text controls . . . . . . . . . . . . . . . . . . 3-31
Text control properties. . . . . . . . . . . 3-31
Properties of memo and rich text Using helper objects . . . . . . . . . . . . . . . 3-46
controls. . . . . . . . . . . . . . . . . . .3-31 Working with lists. . . . . . . . . . . . . . . 3-47
Rich text controls (VCL only) . . . . . . .3-32 Working with string lists . . . . . . . . . . . 3-47
Specialized input controls. . . . . . . . . . .3-32 Loading and saving string lists. . . . . . 3-48
Scroll bars . . . . . . . . . . . . . . . . . .3-32 Creating a new string list . . . . . . . . . 3-48
Track bars . . . . . . . . . . . . . . . . . .3-33 Manipulating strings in a list. . . . . . . 3-50
Up-down controls (VCL only). . . . . . .3-33 Associating objects with a string list. . . 3-52
Spin edit controls (CLX only) . . . . . . .3-33 Windows registry and INI files . . . . . . . 3-52
Hot key controls (VCL only). . . . . . . .3-33 Using TIniFile (VCL only) . . . . . . . . 3-52
Splitter controls . . . . . . . . . . . . . . .3-34 Using TRegistry . . . . . . . . . . . . . . 3-53
Buttons and similar controls . . . . . . . . .3-34 Using TRegIniFile . . . . . . . . . . . . . 3-53
Button controls . . . . . . . . . . . . . . .3-34 Creating drawing spaces . . . . . . . . . . . 3-54
Bitmap buttons . . . . . . . . . . . . . . .3-35 Printing. . . . . . . . . . . . . . . . . . . . . 3-54
Speed buttons . . . . . . . . . . . . . . . .3-35 Using streams . . . . . . . . . . . . . . . . . 3-55
Check boxes . . . . . . . . . . . . . . . . .3-35
Chapter 4
Radio buttons . . . . . . . . . . . . . . . .3-35
Toolbars . . . . . . . . . . . . . . . . . . .3-36 Common programming tasks 4-1
Cool bars (VCL only). . . . . . . . . . . .3-36 Understanding classes . . . . . . . . . . . . . . .4-1
Handling lists. . . . . . . . . . . . . . . . . .3-36 Defining classes . . . . . . . . . . . . . . . . . . .4-2
List boxes and check-list boxes . . . . . .3-37 Handling exceptions . . . . . . . . . . . . . . . .4-4
Combo boxes . . . . . . . . . . . . . . . .3-37 Protecting blocks of code. . . . . . . . . . . .4-4
Tree views . . . . . . . . . . . . . . . . . .3-38 Responding to exceptions. . . . . . . . . .4-5
List views . . . . . . . . . . . . . . . . . .3-38 Exceptions and the flow of control. . . . .4-6
Date-time pickers and month Nesting exception responses . . . . . . . .4-6
calendars (VCL only). . . . . . . . . . .3-39 Protecting resource allocations. . . . . . . . .4-7
Grouping components. . . . . . . . . . . . .3-39 What kind of resources need
Group boxes and radio groups . . . . . .3-39 protection? . . . . . . . . . . . . . . . . .4-7
Panels . . . . . . . . . . . . . . . . . . . .3-39 Creating a resource protection block. . . .4-8
Scroll boxes . . . . . . . . . . . . . . . . .3-40 Handling RTL exceptions. . . . . . . . . . . .4-9
Tab controls . . . . . . . . . . . . . . . . .3-40 What are RTL exceptions? . . . . . . . . .4-9
Page controls . . . . . . . . . . . . . . . .3-40 Creating an exception handler . . . . . . 4-10
Header controls. . . . . . . . . . . . . . .3-41 Exception handling statements. . . . . . 4-11
Providing visual feedback. . . . . . . . . . .3-41 Using the exception instance . . . . . . . 4-11
Labels and static text components . . . .3-41 Scope of exception handlers . . . . . . . 4-12
Status bars. . . . . . . . . . . . . . . . . .3-42 Providing default exception
Progress bars . . . . . . . . . . . . . . . .3-42 handlers. . . . . . . . . . . . . . . . . . 4-12
Help and hint properties. . . . . . . . . .3-42 Handling classes of exceptions. . . . . . 4-13
Grids. . . . . . . . . . . . . . . . . . . . . . .3-43 Reraising the exception . . . . . . . . . . 4-13
Draw grids. . . . . . . . . . . . . . . . . .3-43 Handling component exceptions . . . . . . 4-14
String grids . . . . . . . . . . . . . . . . .3-43 Exception handling with external
Value list editors (VCL only) . . . . . . . . .3-43 sources . . . . . . . . . . . . . . . . . . . . 4-15
Displaying graphics . . . . . . . . . . . . . .3-44 Silent exceptions. . . . . . . . . . . . . . . . 4-15
Images . . . . . . . . . . . . . . . . . . . .3-44 Defining your own exceptions. . . . . . . . 4-16
Shapes . . . . . . . . . . . . . . . . . . . .3-44 Declaring an exception object type. . . . 4-16
Bevels . . . . . . . . . . . . . . . . . . . .3-45 Raising an exception. . . . . . . . . . . . 4-17
Paint boxes. . . . . . . . . . . . . . . . . .3-45 Using interfaces. . . . . . . . . . . . . . . . . . 4-17
Animation control (VCL only). . . . . . .3-45 Interfaces as a language feature . . . . . . . 4-18
Developing dialog boxes . . . . . . . . . . .3-45 Implementing interfaces across
Using open dialog boxes. . . . . . . . . .3-46 the hierarchy . . . . . . . . . . . . . . . 4-18
Using interfaces with procedures. . . . .4-20 Passing a local variable as a PChar . . . 4-48
Implementing IInterface. . . . . . . . . . . .4-20 Compiler directives for strings. . . . . . . . 4-49
TInterfacedObject . . . . . . . . . . . . . . .4-21 Strings and characters: related topics . . . . 4-50
Using the as operator . . . . . . . . . . . . .4-21 Working with files . . . . . . . . . . . . . . . . 4-50
Reusing code and delegation . . . . . . . . .4-22 Manipulating files. . . . . . . . . . . . . . . 4-50
Using implements for delegation . . . . .4-22 Deleting a file. . . . . . . . . . . . . . . . 4-50
Aggregation . . . . . . . . . . . . . . . . .4-23 Finding a file . . . . . . . . . . . . . . . . 4-51
Memory management of interface Renaming a file. . . . . . . . . . . . . . . 4-52
objects . . . . . . . . . . . . . . . . . . . . .4-24 File date-time routines . . . . . . . . . . 4-52
Using reference counting . . . . . . . . .4-24 Copying a file . . . . . . . . . . . . . . . 4-53
Not using reference counting . . . . . . .4-25 File types with file I/O . . . . . . . . . . . . 4-53
Using interfaces in distributed Using file streams . . . . . . . . . . . . . . . 4-54
applications (VCL only) . . . . . . . . . . .4-26 Creating and opening files . . . . . . . . 4-54
Defining custom variants . . . . . . . . . . . . .4-27 Using the file handle . . . . . . . . . . . 4-55
Storing a custom variant type’s data. . . . .4-28 Reading and writing to files . . . . . . . 4-55
Creating a class to enable the custom Reading and writing strings . . . . . . . 4-56
variant type . . . . . . . . . . . . . . . . . .4-28 Seeking a file . . . . . . . . . . . . . . . . 4-56
Enabling casting . . . . . . . . . . . . . .4-29 File position and size . . . . . . . . . . . 4-57
Implementing binary operations . . . . .4-30 Copying. . . . . . . . . . . . . . . . . . . 4-57
Implementing comparison operations . .4-32 Converting measurements. . . . . . . . . . . . 4-58
Implementing unary operations . . . . .4-34 Performing conversions . . . . . . . . . . . 4-58
Copying and clearing custom Performing simple conversions . . . . . 4-58
variants. . . . . . . . . . . . . . . . . . .4-34 Performing complex conversions . . . . 4-58
Loading and saving custom variant Adding new measurement types . . . . . . 4-59
values. . . . . . . . . . . . . . . . . . . .4-35 Creating a simple conversion family
Using the TCustomVariantType and adding units. . . . . . . . . . . . . 4-59
descendant. . . . . . . . . . . . . . . . .4-36 Using a conversion function . . . . . . . 4-60
Writing utilities to work with a custom Using a class to manage
variant type . . . . . . . . . . . . . . . . . .4-36 conversions . . . . . . . . . . . . . . . . 4-62
Supporting properties and methods in Defining data types. . . . . . . . . . . . . . . . 4-64
custom variants. . . . . . . . . . . . . . . .4-37
Chapter 5
Using TInvokeableVariantType . . . . . .4-37
Using TPublishableVariantType. . . . . .4-39 Building applications, components,
Working with strings . . . . . . . . . . . . . . .4-39 and libraries 5-1
Character types. . . . . . . . . . . . . . . . .4-39
Creating applications. . . . . . . . . . . . . . . .5-1
String types . . . . . . . . . . . . . . . . . . .4-40
GUI applications. . . . . . . . . . . . . . . . .5-1
Short strings. . . . . . . . . . . . . . . . .4-40
User interface models . . . . . . . . . . . .5-2
Long strings . . . . . . . . . . . . . . . . .4-41
SDI applications . . . . . . . . . . . . . . .5-2
WideString. . . . . . . . . . . . . . . . . .4-41
MDI applications. . . . . . . . . . . . . . .5-2
PChar types . . . . . . . . . . . . . . . . .4-42
Setting IDE, project, and compilation
OpenString . . . . . . . . . . . . . . . . .4-42
options . . . . . . . . . . . . . . . . . . .5-3
Runtime library string handling routines . .4-42
Programming templates . . . . . . . . . . . .5-3
Wide character routines . . . . . . . . . .4-43
Console applications . . . . . . . . . . . . . .5-3
Commonly used long string routines. . .4-43
Service applications. . . . . . . . . . . . . . .5-4
Declaring and initializing strings. . . . . . .4-46
Service threads. . . . . . . . . . . . . . . .5-6
Mixing and converting string types . . . . .4-47
Service name properties. . . . . . . . . . .5-7
String to PChar conversions. . . . . . . . . .4-47
Debugging services . . . . . . . . . . . . .5-8
String dependencies . . . . . . . . . . . .4-47
Creating packages and DLLs . . . . . . . . . . .5-9
Returning a PChar local variable . . . . .4-48
When to use packages and DLLs . . . . . . .5-9
Writing database applications . . . . . . . . . .5-10 Registering Help selectors . . . . . . . . 5-27
Distributing database applications. . . . . .5-11 Using Help in a VCL Application. . . . . . . . 5-28
Creating Web server applications . . . . . . . .5-11 How TApplication processes VCL
Using Web Broker . . . . . . . . . . . . . . .5-11 Help. . . . . . . . . . . . . . . . . . . . . . 5-28
Creating WebSnap applications. . . . . . . .5-13 How VCL controls process Help. . . . . . . 5-28
Using InternetExpress . . . . . . . . . . . . .5-13 Using Help in a CLX Application. . . . . . . . 5-29
Creating Web Services applications . . . . .5-13 How TApplication processes CLX
Writing applications using COM. . . . . . . . .5-14 Help. . . . . . . . . . . . . . . . . . . . . . 5-29
Using COM and DCOM. . . . . . . . . . . .5-14 How CLX controls process Help. . . . . . . 5-29
Using MTS and COM+ . . . . . . . . . . . .5-14 Calling a Help system directly . . . . . . . . . 5-30
Using data modules . . . . . . . . . . . . . . . .5-15 Using IHelpSystem . . . . . . . . . . . . . . . . 5-30
Creating and editing standard data Customizing the IDE Help system . . . . . . . 5-30
modules . . . . . . . . . . . . . . . . . . . .5-15
Chapter 6
Naming a data module and its unit
file. . . . . . . . . . . . . . . . . . . . . .5-16 Developing the application user
Placing and naming components . . . . .5-17 interface 6-1
Using component properties and
Controlling application behavior . . . . . . . . .6-1
events in a data module . . . . . . . . .5-17
Using the main form . . . . . . . . . . . . . .6-1
Creating business rules in a data
Adding forms . . . . . . . . . . . . . . . . . .6-2
module. . . . . . . . . . . . . . . . . . .5-18
Linking forms . . . . . . . . . . . . . . . .6-2
Accessing a data module from a form . . . .5-18
Avoiding circular unit references. . . . . .6-2
Adding a remote data module to an
Hiding the main form. . . . . . . . . . . . . .6-3
application server project . . . . . . . . . .5-19
Working at the application level. . . . . . . .6-3
Using the Object Repository . . . . . . . . . . .5-19
Handling the screen. . . . . . . . . . . . . . .6-3
Sharing items within a project . . . . . . . .5-19
Managing layout . . . . . . . . . . . . . . . .6-4
Adding items to the Object Repository . . .5-19
Responding to event notification . . . . . . . . .6-5
Sharing objects in a team environment . . .5-20
Using forms . . . . . . . . . . . . . . . . . . . . .6-5
Using an Object Repository item in
Controlling when forms reside in
a project . . . . . . . . . . . . . . . . . . . .5-20
memory. . . . . . . . . . . . . . . . . . . . .6-6
Copying an item . . . . . . . . . . . . . .5-20
Displaying an auto-created form. . . . . .6-6
Inheriting an item. . . . . . . . . . . . . .5-20
Creating forms dynamically . . . . . . . .6-6
Using an item . . . . . . . . . . . . . . . .5-21
Creating modeless forms such as
Using project templates . . . . . . . . . . . .5-21
windows . . . . . . . . . . . . . . . . . .6-7
Modifying shared items . . . . . . . . . . . .5-21
Using a local variable to create a form
Specifying a default project, new form,
instance . . . . . . . . . . . . . . . . . . .6-7
and main form . . . . . . . . . . . . . . . .5-21
Passing additional arguments to forms. . . .6-8
Enabling Help in applications . . . . . . . . . .5-22
Retrieving data from forms. . . . . . . . . . .6-9
Help system interfaces. . . . . . . . . . . . .5-22
Retrieving data from modeless forms . . .6-9
Implementing ICustomHelpViewer . . . . .5-23
Retrieving data from modal forms. . . . 6-10
Communicating with the Help
Reusing components and groups of
Manager . . . . . . . . . . . . . . . . . . . .5-23
components . . . . . . . . . . . . . . . . . . . 6-12
Asking the Help Manager for
Creating and using component templates . . . 6-13
information . . . . . . . . . . . . . . . . . .5-24
Working with frames . . . . . . . . . . . . . . . 6-13
Displaying keyword-based Help. . . . . . .5-24
Creating frames . . . . . . . . . . . . . . . . 6-14
Displaying tables of contents . . . . . . . . .5-25
Adding frames to the component
Implementing IExtendedHelpViewer . . . .5-26
palette. . . . . . . . . . . . . . . . . . . . . 6-14
Implementing IHelpSelector . . . . . . . . .5-26
Using and modifying frames. . . . . . . . . 6-14
Registering Help system objects . . . . . . .5-27
Sharing frames. . . . . . . . . . . . . . . . . 6-15
Registering Help viewers . . . . . . . . .5-27
Organizing actions for toolbars and Merging menus . . . . . . . . . . . . . . . . 6-40
menus . . . . . . . . . . . . . . . . . . . . . . .6-16 Specifying the active menu: Menu
What is an action? . . . . . . . . . . . . . . .6-17 property. . . . . . . . . . . . . . . . . . 6-40
Setting up action bands . . . . . . . . . . . .6-18 Determining the order of merged menu
Creating toolbars and menus . . . . . . . . .6-18 items: GroupIndex property . . . . . . 6-40
Adding color, patterns, or pictures to Importing resource files . . . . . . . . . . . 6-41
menus, buttons, and toolbars . . . . . .6-20 Designing toolbars and cool bars . . . . . . . . 6-41
Adding icons to menus and toolbars. . .6-21 Adding a toolbar using a panel
Creating toolbars and menus that component . . . . . . . . . . . . . . . . . . 6-42
users can customize. . . . . . . . . . . .6-21 Adding a speed button to a panel . . . . 6-43
Hiding unused items and categories Assigning a speed button’s glyph . . . . 6-43
in action bands . . . . . . . . . . . . . .6-22 Setting the initial condition of a
Using action lists. . . . . . . . . . . . . . . . . .6-23 speed button . . . . . . . . . . . . . . . 6-43
Setting up action lists . . . . . . . . . . . . .6-23 Creating a group of speed buttons. . . . 6-44
What happens when an action fires . . . . .6-24 Allowing toggle buttons . . . . . . . . . 6-44
Responding with events . . . . . . . . . .6-24 Adding a toolbar using the toolbar
How actions find their targets. . . . . . .6-26 component . . . . . . . . . . . . . . . . . . 6-44
Updating actions . . . . . . . . . . . . . . . .6-26 Adding a tool button . . . . . . . . . . . 6-45
Predefined action classes . . . . . . . . . . .6-26 Assigning images to tool buttons . . . . 6-45
Writing action components . . . . . . . . . .6-27 Setting tool button appearance and
Registering actions. . . . . . . . . . . . . . .6-28 initial conditions . . . . . . . . . . . . . 6-46
Creating and managing menus. . . . . . . . . .6-29 Creating groups of tool buttons . . . . . 6-46
Opening the Menu Designer . . . . . . . . .6-29 Allowing toggled tool buttons . . . . . . 6-46
Building menus. . . . . . . . . . . . . . . . .6-31 Adding a cool bar component . . . . . . . . 6-47
Naming menus . . . . . . . . . . . . . . .6-31 Setting the appearance of the
Naming the menu items . . . . . . . . . .6-31 cool bar . . . . . . . . . . . . . . . . . . 6-47
Adding, inserting, and deleting Responding to clicks . . . . . . . . . . . . . 6-48
menu items . . . . . . . . . . . . . . . .6-32 Assigning a menu to a tool button. . . . 6-48
Adding separator bars . . . . . . . . . . .6-32 Adding hidden toolbars . . . . . . . . . . . 6-48
Specifying accelerator keys and Hiding and showing toolbars . . . . . . . . 6-48
keyboard shortcuts . . . . . . . . . . . .6-33 Demo programs . . . . . . . . . . . . . . . . 6-49
Creating submenus. . . . . . . . . . . . . . .6-33
Chapter 7
Creating submenus by demoting
existing menus . . . . . . . . . . . . . .6-34 Working with controls 7-1
Moving menu items . . . . . . . . . . . .6-34 Implementing drag-and-drop in controls . . . .7-1
Adding images to menu items . . . . . .6-35 Starting a drag operation. . . . . . . . . . . .7-1
Viewing the menu . . . . . . . . . . . . .6-35 Accepting dragged items. . . . . . . . . . . .7-2
Editing menu items in the Object Dropping items . . . . . . . . . . . . . . . . .7-2
Inspector. . . . . . . . . . . . . . . . . . . .6-35 Ending a drag operation . . . . . . . . . . . .7-3
Using the Menu Designer context Customizing drag and drop with a
menu. . . . . . . . . . . . . . . . . . . . . .6-36 drag object . . . . . . . . . . . . . . . . . . .7-3
Commands on the context menu . . . . .6-36 Changing the drag mouse pointer. . . . . . .7-4
Switching between menus at design Implementing drag-and-dock in controls . . . .7-4
time. . . . . . . . . . . . . . . . . . . . .6-37 Making a windowed control a docking
Using menu templates. . . . . . . . . . . . .6-37 site. . . . . . . . . . . . . . . . . . . . . . . .7-4
Saving a menu as a template . . . . . . . . .6-38 Making a control a dockable child. . . . . . .7-4
Naming conventions for template Controlling how child controls are
menu items and event handlers. . . . .6-39 docked . . . . . . . . . . . . . . . . . . . . .7-5
Manipulating menu items at runtime . . . .6-40
Controlling how child controls are Making scrollable graphics . . . . . . . . 8-16
undocked . . . . . . . . . . . . . . . . . . . 7-6 Adding an image control . . . . . . . . . 8-17
Controlling how child controls respond Loading and saving graphics files. . . . . . 8-18
to drag-and-dock operations . . . . . . . . 7-6 Loading a picture from a file . . . . . . . 8-19
Working with text in controls. . . . . . . . . . . 7-6 Saving a picture to a file. . . . . . . . . . 8-19
Setting text alignment . . . . . . . . . . . . . 7-7 Replacing the picture . . . . . . . . . . . 8-20
Adding scroll bars at runtime. . . . . . . . . 7-7 Using the clipboard with graphics . . . . . 8-21
Adding the clipboard object. . . . . . . . . . 7-8 Copying graphics to the clipboard. . . . 8-21
Selecting text . . . . . . . . . . . . . . . . . . 7-8 Cutting graphics to the clipboard . . . . 8-21
Selecting all text . . . . . . . . . . . . . . . . 7-9 Pasting graphics from the clipboard. . . 8-22
Cutting, copying, and pasting text . . . . . . 7-9 Rubber banding example. . . . . . . . . . . 8-23
Deleting selected text . . . . . . . . . . . . . 7-9 Responding to the mouse. . . . . . . . . 8-23
Disabling menu items . . . . . . . . . . . . .7-10 Responding to a mouse-down action . . 8-24
Providing a pop-up menu. . . . . . . . . . .7-10 Adding a field to a form object to track
Handling the OnPopup event. . . . . . . . .7-11 mouse actions . . . . . . . . . . . . . . 8-26
Adding graphics to controls . . . . . . . . . . .7-11 Refining line drawing . . . . . . . . . . . 8-27
Indicating that a control is Working with multimedia . . . . . . . . . . . . 8-28
owner-drawn . . . . . . . . . . . . . . . . .7-12 Adding silent video clips to an
Adding graphical objects to a string list . . .7-12 application . . . . . . . . . . . . . . . . . . 8-29
Adding images to an application . . . . .7-13 Example of adding silent video clips . . 8-30
Adding images to a string list. . . . . . .7-13 Adding audio and/or video clips to an
Drawing owner-drawn items . . . . . . .7-13 application . . . . . . . . . . . . . . . . . . 8-30
Sizing owner-draw items . . . . . . . . . . .7-14 Example of adding audio and/or video
Drawing owner-draw items. . . . . . . . . .7-15 clips (VCL only) . . . . . . . . . . . . . 8-32
Chapter 8 Chapter 9
Working with graphics and Writing multi-threaded applications 9-1
multimedia 8-1 Defining thread objects. . . . . . . . . . . . . . .9-1
Initializing the thread. . . . . . . . . . . . . .9-2
Overview of graphics programming. . . . . . . 8-1
Assigning a default priority . . . . . . . .9-2
Refreshing the screen . . . . . . . . . . . . . 8-2
Indicating when threads are freed . . . . .9-3
Types of graphic objects . . . . . . . . . . . . 8-3
Writing the thread function . . . . . . . . . .9-4
Common properties and methods of
Using the main VCL/CLX thread . . . . .9-4
Canvas. . . . . . . . . . . . . . . . . . . . . 8-4
Using thread-local variables . . . . . . . .9-5
Using the properties of the Canvas
Checking for termination by other
object . . . . . . . . . . . . . . . . . . . . . 8-5
threads . . . . . . . . . . . . . . . . . . .9-5
Using pens. . . . . . . . . . . . . . . . . . 8-5
Handling exceptions in the thread
Using brushes. . . . . . . . . . . . . . . . 8-8
function . . . . . . . . . . . . . . . . . . .9-6
Reading and setting pixels. . . . . . . . . 8-9
Writing clean-up code. . . . . . . . . . . . . .9-6
Using Canvas methods to draw graphic
Coordinating threads. . . . . . . . . . . . . . . .9-7
objects . . . . . . . . . . . . . . . . . . . . . 8-9
Avoiding simultaneous access . . . . . . . . .9-7
Drawing lines and polylines. . . . . . . .8-10
Locking objects. . . . . . . . . . . . . . . .9-7
Drawing shapes. . . . . . . . . . . . . . .8-11
Using critical sections . . . . . . . . . . . .9-7
Handling multiple drawing objects in
Using the multi-read exclusive-write
your application . . . . . . . . . . . . . . .8-12
synchronizer . . . . . . . . . . . . . . . .9-8
Keeping track of which drawing tool
Other techniques for sharing memory. . .9-8
to use . . . . . . . . . . . . . . . . . . . .8-12
Waiting for other threads. . . . . . . . . . . .9-9
Changing the tool with speed buttons . .8-13
Waiting for a thread to finish
Using drawing tools . . . . . . . . . . . .8-13
executing . . . . . . . . . . . . . . . . . .9-9
Drawing on a graphic . . . . . . . . . . . . .8-16
Waiting for a task to be completed . . . . 9-9 Porting Internet applications to Linux . . 10-29
Executing thread objects . . . . . . . . . . . . .9-10
Chapter 11
Overriding the default priority . . . . . . . .9-11
Starting and stopping threads . . . . . . . .9-11 Working with packages and
Debugging multi-threaded applications . . . .9-12 components 11-1
Chapter 10 Why use packages?. . . . . . . . . . . . . . . . 11-2
Packages and standard DLLs . . . . . . . . 11-2
Using CLX for cross-platform
Runtime packages . . . . . . . . . . . . . . . . 11-2
development 10-1
Using packages in an application . . . . . . 11-3
Creating cross-platform applications . . . . . .10-1 Dynamically loading packages . . . . . . . 11-4
Porting VCL applications to CLX . . . . . . . .10-2 Deciding which runtime packages
Porting techniques . . . . . . . . . . . . . . .10-3 to use . . . . . . . . . . . . . . . . . . . . . 11-4
Platform-specific ports . . . . . . . . . . .10-3 Custom packages . . . . . . . . . . . . . . . 11-4
Cross-platform ports . . . . . . . . . . . .10-3 Design-time packages . . . . . . . . . . . . . . 11-5
Windows emulation ports . . . . . . . . .10-3 Installing component packages . . . . . . . 11-5
Porting your application. . . . . . . . . . . .10-4 Creating and editing packages . . . . . . . . . 11-6
CLX versus VCL . . . . . . . . . . . . . . . .10-5 Creating a package . . . . . . . . . . . . . . 11-6
What CLX does differently . . . . . . . . . .10-6 Editing an existing package . . . . . . . . . 11-7
Look and feel . . . . . . . . . . . . . . . .10-6 Editing package source files manually . . . 11-8
Styles. . . . . . . . . . . . . . . . . . . . .10-6 Understanding the structure of a
Variants . . . . . . . . . . . . . . . . . . .10-7 package. . . . . . . . . . . . . . . . . . . . 11-8
Registry . . . . . . . . . . . . . . . . . . .10-7 Naming packages . . . . . . . . . . . . . 11-8
Other differences . . . . . . . . . . . . . .10-7 Requires clause. . . . . . . . . . . . . . . 11-8
Missing in CLX . . . . . . . . . . . . . . . . .10-8 Contains clause. . . . . . . . . . . . . . . 11-9
Features that will not port. . . . . . . . . . .10-8 Compiling packages . . . . . . . . . . . . .11-10
CLX and VCL unit comparison. . . . . . . .10-9 Package-specific compiler
Differences in CLX object directives . . . . . . . . . . . . . . . . .11-10
constructors . . . . . . . . . . . . . . . . . 10-13 Using the command-line compiler
Sharing source files between and linker . . . . . . . . . . . . . . . . .11-12
Windows and Linux . . . . . . . . . . . . 10-13 Package files created by a successful
Environmental differences between compilation. . . . . . . . . . . . . . . .11-12
Windows and Linux . . . . . . . . . . . . 10-14 Deploying packages . . . . . . . . . . . . . . .11-13
Directory structure on Linux . . . . . . . . 10-16 Deploying applications that use
Writing portable code . . . . . . . . . . . . 10-17 packages . . . . . . . . . . . . . . . . . . .11-13
Using conditional directives. . . . . . . 10-18 Distributing packages to other
Terminating conditional directives . . . 10-19 developers . . . . . . . . . . . . . . . . . .11-13
Emitting messages . . . . . . . . . . . . 10-20 Package collection files . . . . . . . . . . . .11-13
Including inline assembler code. . . . . 10-20
Chapter 12
Messages and system events . . . . . . . . 10-21
Programming differences on Linux . . . . 10-22 Creating international applications 12-1
Cross-platform database applications . . . . . 10-23 Internationalization and localization . . . . . . 12-1
dbExpress differences . . . . . . . . . . . . 10-23 Internationalization . . . . . . . . . . . . . . 12-1
Component-level differences . . . . . . . . 10-24 Localization . . . . . . . . . . . . . . . . . . 12-2
User interface-level differences . . . . . . . 10-25 Internationalizing applications . . . . . . . . . 12-2
Porting database applications to Enabling application code . . . . . . . . . . 12-2
Linux. . . . . . . . . . . . . . . . . . . . . 10-25 Character sets . . . . . . . . . . . . . . . 12-2
Updating data in dbExpress OEM and ANSI character sets . . . . . . 12-3
applications . . . . . . . . . . . . . . . . . 10-27 Multibyte character sets. . . . . . . . . . 12-3
Cross-platform Internet applications . . . . . 10-29 Wide characters . . . . . . . . . . . . . . 12-4
Including bi-directional functionality Software license requirements. . . . . . . . . 13-14
in applications. . . . . . . . . . . . . . .12-4 DEPLOY . . . . . . . . . . . . . . . . . . . 13-14
BiDiMode property. . . . . . . . . . . . .12-6 README. . . . . . . . . . . . . . . . . . . 13-15
Locale-specific features. . . . . . . . . . .12-8 No-nonsense license agreement . . . . . . 13-15
Designing the user interface. . . . . . . . . .12-9 Third-party product documentation . . . 13-15
Text . . . . . . . . . . . . . . . . . . . . . .12-9
Part II
Graphic images . . . . . . . . . . . . . . .12-9
Formats and sort order. . . . . . . . . . 12-10 Developing database applications
Keyboard mappings . . . . . . . . . . . 12-10
Isolating resources . . . . . . . . . . . . . . 12-10 Chapter 14
Creating resource DLLs . . . . . . . . . . . 12-10 Designing database applications 14-1
Using resource DLLs. . . . . . . . . . . . . 12-12
Using databases. . . . . . . . . . . . . . . . . . 14-1
Dynamic switching of resource DLLs . . . 12-13
Types of databases. . . . . . . . . . . . . . . 14-2
Localizing applications . . . . . . . . . . . . . 12-13
Database security . . . . . . . . . . . . . . . 14-3
Localizing resources . . . . . . . . . . . . . 12-13
Transactions . . . . . . . . . . . . . . . . . . 14-4
Chapter 13 Referential integrity, stored procedures,
Deploying applications 13-1 and triggers. . . . . . . . . . . . . . . . . . 14-5
Database architecture. . . . . . . . . . . . . . . 14-5
Deploying general applications . . . . . . . . .13-1
General structure . . . . . . . . . . . . . . . 14-6
Using installation programs. . . . . . . . . .13-2
The user interface form . . . . . . . . . . 14-6
Identifying application files . . . . . . . .13-2
The data module. . . . . . . . . . . . . . 14-6
Application files. . . . . . . . . . . . . . .13-3
Connecting directly to a database
Package files. . . . . . . . . . . . . . . . .13-3
server . . . . . . . . . . . . . . . . . . . . . 14-7
Merge modules . . . . . . . . . . . . . . .13-3
Using a dedicated file on disk . . . . . . . . 14-9
ActiveX controls . . . . . . . . . . . . . .13-5
Connecting to another dataset. . . . . . . 14-10
Helper applications. . . . . . . . . . . . .13-5
Connecting a client dataset to another
DLL locations . . . . . . . . . . . . . . . .13-5
dataset in the same application. . . . .14-11
Deploying CLX applications . . . . . . . . . . .13-6
Using a multi-tiered architecture. . . . 14-12
Deploying database applications. . . . . . . . .13-6
Combining approaches. . . . . . . . . . . 14-14
Deploying dbExpress database
Designing the user interface. . . . . . . . . . 14-15
applications . . . . . . . . . . . . . . . . . .13-7
Analyzing data . . . . . . . . . . . . . . . 14-15
Deploying BDE applications . . . . . . . . .13-8
Writing reports. . . . . . . . . . . . . . . . 14-16
Borland Database Engine . . . . . . . . .13-8
SQL Links . . . . . . . . . . . . . . . . . .13-8 Chapter 15
Deploying multi-tiered database Using data controls 15-1
applications (DataSnap) . . . . . . . . . . .13-9
Using common data control features . . . . . . 15-2
Deploying Web applications . . . . . . . . . . .13-9
Associating a data control with a
Deployment on Apache . . . . . . . . . . . 13-10
dataset . . . . . . . . . . . . . . . . . . . . 15-3
Programming for varying host
Changing the associated dataset
environments. . . . . . . . . . . . . . . . . . 13-11
at runtime. . . . . . . . . . . . . . . . . 15-3
Screen resolutions and color depths . . . . 13-11
Enabling and disabling the data
Considerations when not
source . . . . . . . . . . . . . . . . . . . 15-4
dynamically resizing . . . . . . . . . . 13-11
Responding to changes mediated by
Considerations when dynamically
the data source . . . . . . . . . . . . . . 15-4
resizing forms and controls . . . . . . 13-12
Editing and updating data . . . . . . . . . . 15-5
Accommodating varying color
Enabling editing in controls on user
depths . . . . . . . . . . . . . . . . . . 13-13
entry. . . . . . . . . . . . . . . . . . . . 15-5
Fonts. . . . . . . . . . . . . . . . . . . . . . 13-13
Editing data in a control. . . . . . . . . . 15-5
Operating systems versions. . . . . . . . . 13-14
Disabling and enabling data display. . . . .15-6 Hiding and showing navigator
Refreshing data display . . . . . . . . . . . .15-6 buttons at runtime . . . . . . . . . . . 15-29
Enabling mouse, keyboard, and timer Displaying fly-over help . . . . . . . . . . 15-30
events . . . . . . . . . . . . . . . . . . . . .15-7 Using a single navigator for multiple
Choosing how to organize the data . . . . . . .15-7 datasets . . . . . . . . . . . . . . . . . . . 15-30
Displaying a single record. . . . . . . . . . .15-7
Chapter 16
Displaying data as labels. . . . . . . . . .15-8
Displaying and editing fields in an Using decision support
edit box. . . . . . . . . . . . . . . . . . .15-8 components 16-1
Displaying and editing text in a
Overview . . . . . . . . . . . . . . . . . . . . . 16-1
memo control . . . . . . . . . . . . . . .15-8
About crosstabs . . . . . . . . . . . . . . . . . . 16-2
Displaying and editing text in a rich
One-dimensional crosstabs. . . . . . . . . . 16-2
edit memo control. . . . . . . . . . . . .15-9
Multidimensional crosstabs . . . . . . . . . 16-3
Displaying and editing graphics
Guidelines for using decision support
fields in an image control . . . . . . . .15-9
components . . . . . . . . . . . . . . . . . . . 16-3
Displaying and editing data in list
Using datasets with decision support
and combo boxes . . . . . . . . . . . . 15-10
components . . . . . . . . . . . . . . . . . . . 16-4
Handling Boolean field values with
Creating decision datasets with TQuery
check boxes . . . . . . . . . . . . . . . 15-12
or TTable . . . . . . . . . . . . . . . . . . . 16-5
Restricting field values with radio
Creating decision datasets with the
controls. . . . . . . . . . . . . . . . . . 15-13
Decision Query editor. . . . . . . . . . . . 16-6
Displaying multiple records. . . . . . . . . 15-14
Using decision cubes . . . . . . . . . . . . . . . 16-7
Viewing and editing data with TDBGrid . . . 15-15
Decision cube properties and events . . . . 16-7
Using a grid control in its default
Using the Decision Cube editor . . . . . . . 16-7
state . . . . . . . . . . . . . . . . . . . . . 15-15
Viewing and changing dimension
Creating a customized grid . . . . . . . . . 15-16
settings . . . . . . . . . . . . . . . . . . 16-8
Understanding persistent columns . . . 15-16
Setting the maximum available
Creating persistent columns. . . . . . . 15-17
dimensions and summaries. . . . . . . 16-8
Deleting persistent columns. . . . . . . 15-18
Viewing and changing design
Arranging the order of persistent
options . . . . . . . . . . . . . . . . . . 16-8
columns . . . . . . . . . . . . . . . . . 15-19
Using decision sources . . . . . . . . . . . . . . 16-9
Setting column properties at design
Properties and events. . . . . . . . . . . . . 16-9
time. . . . . . . . . . . . . . . . . . . . 15-19
Using decision pivots. . . . . . . . . . . . . . . 16-9
Defining a lookup list column. . . . . . 15-20
Decision pivot properties. . . . . . . . . . 16-10
Putting a button in a column . . . . . . 15-21
Creating and using decision grids . . . . . . 16-10
Restoring default values to a
Creating decision grids . . . . . . . . . . . 16-10
column . . . . . . . . . . . . . . . . . . 15-21
Using decision grids . . . . . . . . . . . . .16-11
Displaying ADT and array fields. . . . . . 15-21
Opening and closing decision grid
Setting grid options . . . . . . . . . . . . . 15-23
fields. . . . . . . . . . . . . . . . . . . .16-11
Editing in the grid . . . . . . . . . . . . . . 15-25
Reorganizing rows and columns in
Controlling grid drawing . . . . . . . . . . 15-25
decision grids. . . . . . . . . . . . . . .16-11
Responding to user actions at runtime. . . 15-25
Drilling down for detail in
Creating a grid that contains other
decision grids. . . . . . . . . . . . . . .16-11
data-aware controls . . . . . . . . . . . . . . 15-26
Limiting dimension selection in
Navigating and manipulating records. . . . . 15-28
decision grids. . . . . . . . . . . . . . 16-12
Choosing navigator buttons to
Decision grid properties . . . . . . . . . . 16-12
display. . . . . . . . . . . . . . . . . . . . 15-28
Creating and using decision graphs . . . . . 16-13
Hiding and showing navigator
Creating decision graphs. . . . . . . . . . 16-13
buttons at design time . . . . . . . . . 15-29
Using decision graphs . . . . . . . . . . . 16-13