Index
Note: Italicized page locators refer to figures/tables.
Symbols
+, addition operator, 18
, backslash character, 15
b, backspace character, 15
&, bitwise AND, 18
^, bitwise exclusive OR, 18
|, bitwise OR, 18
r, carriage return, 15
--, decrement operator, 18, 19
/, division operator, 18
”, double quote, 15
f, form feed, 15
>, greater than operator, 21
>=, greater than or equal to operator, 21
++, increment operator, 18, 19
==, is equal to operator, 21
!=, is not equal to operator, 21
<<n, left shift n places, 18
<, less than operator, 21
<=, less than or equal to operator, 21
&&, logical AND, 21
||, logical OR, 21
%, modulo, 18
*, multiplication operator, 18
n, newline feed, 15
0, null character, 15
>>n, right shift n places, 18
’, single quote, 15
-, subtraction operator, 18
t, tab character, 15
A
Absolute zero, and Kelvin scale, 47
Abstract classes, 7, 76–80, 192
Abstract class system, and drawing rectangle and circle, 78
AbstractEmployee class, 181
Employee and Boss derived from, 184
AbstractEmployee interface, 182
AbstractEmployee subclasses, 187
AbstractExpression object, in Interpreter pattern, 277
Abstract Factory pattern, 9, 97, 115–121, 154
and Builder pattern, 138
consequences of, 120
and GardenMaker factory, 115–120
more classes added to, 120
Abstraction, in Bridge pattern, 169
abstract keyword, 82
Acceptance, and learning design patterns, 6
accept method, 354, 356, 358, 361
adding to subclasses, 355
Accessor methods, 45
Action methods, 299
ActionVerb class, 280
ActiveX controls, 176
ActiveX Data Objects, 203
Adapter class, 318
Adapter pattern, 9, 155, 157–167, 237
and Bridge pattern, 169
and class adapter, 164–166
making an adapter, 159–160
moving data between lists, 157–158
moving the DataGrid, 160–164
object versus class adapters in C#, 166
pluggable adapters, 166
Proxy pattern, 237
two-way adapters, 166
Adapters, 157
decorators, composites and, 197–198
making, 159–160
Addition operator (+), 18
Address class, Person and Group derived from, 129
addToChain method, 244
Add2.cs program, 16–17
ADO DataSet manipulation, and Clone method, 142
connecting to database in, 204
deleting contents of table in, 205–206
executing query in, 205
reading data from database table in, 204–205
rows added to database tables with, 206–207
using, 203–207
ADO.NET database connections
as proxies, 236
in Façade pattern, 9
ADO.NET Façade
DBTable class, 211–213
making, 209–213
AgeSwimData class, 151
age distribution display for, 150
Aggregation (in UML diagrams), diamonds indicating, 84
Algebraic strings, parsing, 270
Algorithms
and Strategy pattern, 337
Strategy pattern and dynamic selection of, 344
and Template pattern, 345
AND operation, 17
Annotation, and UML diagrams, 85–86
AnnualGarden class, 117
ANSI standards, and SQL, 202
Appearance property, in CheckBoxes, 36
Application class, 31
Approach, 202
Arithmetic statements, combining assignment statements and, 18–19
Array class, 31
of child nodes, 180
Kid objects in, 284
Observer objects added to, 314
and Prototype pattern, 147
and Stack class, 271
StoreFoodPrice objects in, 215
and TriangleForm class, 350
Arrays, in C#, 87–88
Arrow-object state, 336
Assignment statements, combining arithmetic statements and, 18–19
Autohighlight feature, of C# TextBox, 75
Automobile factories, 115
AxsDatabase class, 210
B
Backslash character ( ), 15
Backspace character ( b), 15
Bar graph, and Strategy pattern, 343
BarGraph strategy, 344
BarPlot class, 345
LinePlot class derived from, 342
Bar plots, making, 341–342
BarPlotStrategy class, 340, 341
BarPlot window, 341
Base classes, and Template method, 345, 349, 352
Behavioral patterns, 6, 97, 239–363
Chain of Responsibility, 241–253
Command, 255–268
Interpreter, 269–282
Iterator, 283–290
Mediator, 291–299
Memento, 301–312
Observer, 313–319
State, 321–336
Strategy, 337–344
Template Method, 345–352
Visitor, 353–363
Bitfields, 26
BitList class, 61
Bitmap class, 235
Bitmaps, 231
Bitwise And (&), 18
Bitwise exclusive Or (^), 18
Bitwise operators, 17
Bitwise Or (_), 18
BlueCommand class, 265
derived from ColorCommand class, 267
BlueCommand object, and isUndo method, 265
Blue radio button, in watching colors change program, 314
bmp files, and Buttons, 37
Bonds, with check box interface, 131
Booch, Grady, 81
Boolean operators, 17
Boolean variables, 13
Boolean variable type, spelling in C#, 27
bool object, 31
Borland Paradox, 202
Boss class, 183–184, 187, 357, 358
derived from AbstractEmployee class, 184
visitor classes visiting, 359
BossVisitor, 361
Braces ({ } ), 70
classes/functions surrounded by, 17
indentation styles for, 20
statements in condition enclosed within, 19
Bridge pattern, 9, 155, 169–177, 237
consequences of, 177
extending the bridge, 173–176
UML diagram for, 173
VisList classes, 172
Windows forms as bridges, 176
Bridger class, 173
Bridger interface, defined, 170
btClone_Click event, 149
btConvert_click method, 44
Builder pattern, 76, 98, 107, 129–139, 154
consequences of, 138
inheritance relationships in, 138
Investment Tracker, 130–135
and Prototype pattern, 141
using Items collection in ListBox control, 135–137
Builder program, 176
Builder tools, 176
Butterfly class, 104
Button class, 256, 257, 260, 294, 339
Button events, handling, 119
Buttons, 37, 58, 189, 255, 256
decorating, 191
ToolTip over, 40
Button value, 36
bVacationVisitor class, 358, 359
byte object, 31
C
arrays in line with style used in, 87
differences between C# and, 26
C#, 1, 25. See also Writing Windows C# programs
application building, 31–32
arithmetic and assignment statements combined in, 18–19
arithmetic operators in, 17
character constants in, 14–15
classes used in, 43
class module created from IDE of, 45
cloning in, 142
commas in for loop statements in, 25–26
comments in, 23
common Exception classes in, 91
comparison operators in, 20–21
conditions combined in, 21
converting between numbers and strings in, 13–14
and database structure, 203
decision making in, 19–20
declaring multiple variables in, 14
differences between C and, 26
differences between Java and, 27
do-while statement in, 24
flyweight uses in, 231
for loop in, 24–25
IEnumerator interface in, 284
increment and decrement operators in, 18
logical operators in, 18
looping statements in, 24
as managed language, 30
most common mistake in, 21–22
multiple equal signs for initialization in, 16
numeric constants in, 14
object versus class adapters in, 166
plots drawn in, 341
programming style in, 58
project files, 86
proxies in, 236
simple program in, 16–17
States implementing common interface in, 336
switch statement in, 22
syntax of, 11–27
ternary operator, 23
variables in, 15–16
while loop in, 24
arrays in line with style used in, 87
C# roots in, 29
friend construction in, 302
Caching results, and Composite pattern, 189
Capital class, 60
Capitalization, 27
Caretaker class, 304, 307, 311
Caretaker object, and Memento pattern, 302
Carriage return ( r), 15
Cascading notifications, 318
Case sensitivity, with C#, 11
Casting, 13
Catch blocks, and multiple exceptions, 91–92
catch statement, and exceptions, 90
Celsius temperature scale, 43
absolute zero on, 47
CEO Employee, 184
Chain of responsibility pattern, 8, 239, 241–253, 280
applicability of, 242
chain or tree?, 251–252
class diagram for help system, 251
and Command pattern, 255
examples in C#, 252–253
Help chain, 241
implementation of as linear chain, 252
implementation of as tree structure, 251
kinds of requests with, 252
ListBoxes, 246–248
programming a Help system, 248–251
program on the CD-ROM, 253
purpose of, 253
sample code, 243–246
simple Chain of Responsibility, 242
and syntax tree, 278
visual command interpreter program sample, 243
Chain of Responsibility program, class structure of, 247
Character constants, 14–15
CheckBox, 36–37
Check Box Builder, 133
Check box interface, bonds with, 131
CheckChoice class, 133–134
Checked property, of radio buttons, 37
Child nodes, ArrayList of, 180
Children, and nodes, 179
Circle class, 77
CircleSeeding, 111
instance of, returned by PrelimEvent class, 110
Circle seeding
of 100 Free, 112
of swimmers, 107
Circle state object, 324
list adapter approach to, 165
object adapter versus, 166
Class-based Adapter, 169
Class containment, 55
abstract, 76–78
in C#, 30–31
and design patterns, 7
fetching iterators in, 285–286
in Filtered enumeration, 288
and flyweights, 224
for format and value conversion, 48–51
interaction between for simple drawing program, 322
isolation of, with Abstract Factory, 120
and Mediator pattern, 291
as objects, 53–54
and properties, 56–58
for tables in Façade pattern, 213–215
tangled web of interactions between, in Mediator pattern visual interface, 293
traversing series of, 362
uses for, 43
visiting, 357–358
Class instances, cloning, 142
Class libraries, and visitors, 355
Class methods, declaring as public, private, and protected, 71
Class modules, 45
Class patterns, object patterns versus, 155
Clear button, 291, 294, 297, 302, 321
behavior of, 323
Command objects for, 309
Clear method, and Mediator, 295
Click events, event handler for, 295
Client object, in Interpreter pattern, 277
cloneMe method, inheritance of by AgeSwimData class, 150
Cloning
in C#, 142
and Prototype pattern, 141, 153
closeTriangle method, 352
CLR. See Common language runtime
Cocoon class, 105
Colleague, and Mediator, 293
Colleague elements, 299
Collection objects, 88–90
Collisions, avoiding, 68
ColObserver class, 315–316, 318
Colon (:), 70
and parsing, 49
ColorChain class, 245
Color-changing code, in Windows Controls program
ColorCommand class, 265–266
classes derived from, 267
ColorForm observer, 316
ColorImage class, 248
Color objects, 316
Color observer, 317
Colors, watching changes in, 314–317
ComboBox properties, 38
ComdToolBarButton class, 327–328
Command buttons, 297
automatic language generation with, 281
CommandHolder approach, UML diagram of, 262
CommandHolder interface, 259–262
Command interface, 294, 309, 339
ExitCommand implementing, 84
implementing in new classes, 257
and Undo function, 263
and unDo method, 265
CommandMenu class, 260
Command objects, 256–257, 259, 261, 277
building, 257–259
interactions between Mediator object and, 198
Mediators and, 297
and Undo command, 264
Command pattern, 8, 239, 255–268, 280, 311
and building command objects, 257–259
and CommandHolder interface, 259–262
and command objects, 256–257
consequences of, 259
and Mediator pattern, 297
menu designer interface, 258
menu part of using ComandHolder interface, 262
motivation for, 255–256
programs on the CD-ROM, 268
purpose of, 256
simple program demo, 255
undo function provided by, 262–267
Commands, undoing, 263
Commas, in for loop statements, 25–26
shown in box with turned-down
corner, 86
in UML diagram, 85
Commercial languages, licensing fees and embedding of, 269
Common language runtime, 30
Communication patterns, 5
Company class
with any number of instances of Employee, 85
instances of Person and Employee in, 84
Comparison operators, 20–21, 21
Compilation errors, 22
Compiler error messages, 25
Complex class, 62
Components, ordering, 189
Composite pattern, 9, 155, 179–190, 237, 283, 355, 362
and Boss class, 183–184
building Employee tree, 184–186
composites in .NET, 189
computing salaries, 180–181
consequences of, 188
doubly linked lists, 187
and Employee class, 181–183
implementation of composite, 180
other implementation issues with, 189
programs on the CD-ROM, 190
and self-promotion, 186–187
and simple composite, 188–189
Composites, adapters, decorators and, 197–198
Composition, and UML diagrams, 84–85
ConcreteImplementors, 173
in Bridge pattern, 169
Concrete methods, 347
Conditions, combining, 21
Constants
character, 14–15
numeric, 14
const modifier, in C#, 12
Constructor method, for Rectangle class, 68
Containers, 189
for Command object, 259
as Decorators, 192
Containment, 5
list of swimmers and their times using, 55
contains method, 306
Context interface, 344
Context object, in Interpreter pattern, 277
ControlChain class, 249–250
Controller, 4
Control names, 58
Controls
collection, 189
interactions between, 292–293
Mediator and initialization of, 297
Controls array, and Windows form containing buttons, 194
Convert methods, for converting between numbers and strings, 13
CoolBar, 192
CoolButton, 195
decorating, 191–193
decoration of, with SlashDecorator, 196
CoolDecorator, 196
Coplien, J. O., 141
Copy button, 291
Copy method, and Mediator, 295
Copy-on-write
objects, 232
and Proxy pattern, 237
Coupling between objects, reducing, 253
CpyButton class, 294
CreateText method, 93
Creational patterns, 6, 97–154, 123
Abstract Factory, 115–121
Builder, 129–139
Factory Method, 107–113
Prototype, 141–154
Simple Factory, 99–106
Singleton, 123–127
summary of, 154
csPatterns namespace, 229
Current() property, 284
currentState variable, 325
Cursor class, 235
Customer version, of ListBox, 172
D
Data
getting out of databases, 201–202
moving between lists, 157–158
plotting in Builder pattern, 136
Database class, 220
Databases
connecting with ADO.Net, 204
description of, 199–201
getting data out of, 201–202
kinds of, 202
reading data from with ADO.Net, 204–205
structure of, 203
loading and Façade pattern, 218–219
rows added to using ADO.Net, 206–207
DataColumns, 160
and row selection detection, 162
using, 160–162
DataGrid type, 166
Data manipulation, interface manipulation separated from, 45
Data model, 3
Data modification, and Iterator pattern, 289–290
Data streams, 94
DataTable class, 160, 161, 203, 220
Data types, in C#, 12
classes derived from, 207, 213
classes wrapped in by Façade, 220
DB/2 (IBM), 202
Decisions
making in C#, 19–20
in Temperature class, 47–48
Declaration
property, 56
multiple variable, 14
Decorator class, 191
Decorator panel, code for button added to, 194
Decorator pattern, 155, 191–198, 238
consequences of, 198
decorating CoolButton, 191–193
decorators, adapters, composites and, 198
and event handling, 193–194
and multiple decorators, 195–196
and nonvisual decorators, 197
programs on the CD-ROM, 198
and Proxy pattern, 237
Decrement operator (--), 18, 19
Deep copy, 147
Default case, for switch statements, 22
demo, 59
Delete * from Table SQL statement, 205
Derived classes
caching special cases in, 361
overriding methods in, 72–73
and Template method, 345, 347, 352
Design patterns, 1
C#, 8
defining, 5–6
description of, 3–4
learning, 6–7
and object-oriented approaches, 7–8
studying, 7
Design Patterns: Elements of Reusable Software (Gamma, et al.), 4, 6, 7, 16, 133, 179, 192, 197, 198, 223, 283, 302
and Context class, 323
and State pattern, 321
Template Method discussed in, 347
on Templates, 351
types of iterators described by, 290
Visitor pattern discussed in, 362
Design Patterns Smalltalk Companion, The (Alpert, Brown, and Woolf), 4, 5, 7, 231, 251, 269, 302, 307
Diamonds, in UML diagrams, 84
Director class, 133
Display classes, using Bridge pattern, 169, 170
Division operator (/), 18
Dot (.), and Convert methods, 13
Double angle brackets, 84
Double dispatching, and Visitor pattern, 361
Double quote ( ”), 15
double type, 14
Double variable, methods for, 29
Doubly linked lists, and Composite pattern, 187
do-while loop, 24
draw code, in base Triangle class, 351
drawCommand class, draw method in, 266
DrawData objects, 265
drawHandle method, 333
Drawing, in C#, 66–67
Drawing interface
circle and rectangle objects implementing, 332
VisRectangle implementing, 333
Drawing program, for illustrating State pattern, 321, 322, 323–325
drawLine method, 352
drawList collection, 265
DrawMemento class, 332
draw method, 77, 349, 350, 352
in drawCommand class, 266
as empty method, 79
for Rectangle class, 68
and Visitor class, 354
DrawObject, three subclasses of, 353
draw routine, and Triangle class, 348
draw2ndLine method, 348, 349, 350, 352
E
Editing, and ADO style of programming, 207
Equal signs (multiple), for initialization, 16
e-mail address book, 129
Employee, instances of, in Company, 84
derived from AbstractEmployee class, 184
derived from Person class, 82–83
visitor classes visiting, 359
and Visitor pattern, 355–356
Employee records, in databases, 200
Employee salaries
sorted by magnitude, 201
sorted by name, 201
Employee tree, building, 184–186
EmployeeVisitor, 361
EmpNode class, 185
Empty methods, base classes with, 79
Encapsulation, 7, 8, 47, 51, 71, 337
EndChain class, 250
End of file, testing for, 94–95
End-of-file function, 94
Enumerated types, 27
Enumeration class, 287
Enumeration interface, 9
Enumerator, 182
Enumerator property, of Hashtable, 213
Equal sign (=), for representing assignment of data, 17
Equities class, 132
Error checking, and language introduction, 281
Error handling
in C#, 90
encapsulation of, 51
ET++, 4
Event class, 107–108
EventHandler class, 194
Event handling in Decorator, 193–194
control size and position, 194
layout considerations, 194
Events button, 66
Events classes, 109
Examplar pattern, 141
Examples
FileExit class, 258
Flyweight, 224–230
simple report, 270–271
Exception classes, in C#, 91
Exception errors, 13
Exception object, 94
Exceptions, 9
in C#, 90–91
in file handling, 94
and Singleton pattern, 124
Exceptions class, 31
Execute command, and Butterfly class, 104
Execute method, 259, 260, 280, 295, 328
Execute() method, 256
ExecuteNonQuery method, 205
ExitCommand, Command interface implemented by, 84
ExitMenu class, 257
External iterators, internal iterators versus, 290
F
Façade classes
building, 207–209
building price query, 207–208
Façade pattern, 155, 199–221, 232, 238
ADO.NET database connections in, 9
and building Façade classes, 207–209
building Price table, 215–218
consequences of, 220
creating classes for each table with, 213–215
and Decorator pattern, 198
elements in constitution of, 220
final application with, 219
grocery program using, 209
loading database tables, 218–219
and making ADO.Net Façade, 209–213
program on the CD-ROM, 221
Factory method pattern, 97, 107–113
Events classes, 109–110
and other factories, 112–113
Prototype pattern combined with, 152
StraightSeeding, 110–111
Swimmer class, 109
variations on, 113
when to use, 113
Factory pattern(s), 8, 103–105, 129, 154
Fahrenheit temperature scale, 43, 44
Fast Fourier Transform (FFT), 103
FFT “butterfly,” 103
File compression, with different algorithms, 337
FileExit class, 258
File handling
in C#, 92–94
exceptions in, 94
file object, 92–93
reading to text file, 93
writing to text file, 93–94
FileList box, 246
FileList class, 248
File object, 92–93
Files, opening for reading, 96
Fill button, 321
FillDataSet method, 204
FillState class, 325, 330–331, 336
Fill State object, 330–331
Filtered enumeration, classes used in, 288
Filtered iterators, 286–287
FilteredIterator class, 286–287
Filtered Iterator demo, simple program-illustrated filtered
enumeration, 288
FinalImage class, 235
FirstFirst class, 100
First normal form (1NF), tables in, 200
Floating point numbers, 13
Float variable, methods for, 29
FlyCanvas class, 228
Flyweight demo, 224
Flyweight display, with one folder selected, 225
FlyweightFactor class, 224
Flyweight pattern, 8, 155, 223–232, 238
copy-on write objects, 232
discussion about flyweights, 224
example code, 224–230
flyweight uses in C#, 231
handling the mouse and paint events, 230
program on the CD-ROM, 232
sharable objects, 231–232
Flyweights, generation of, 228
FolderFactory class, 225, 227, 228
Folders
dynamic selection of and FolderFactory, 227
Flyweight demo, 224
Flyweight example and selection of, 229–230
selection of one in Flyweight display, 225
Food class, derived from DBTable, 213
FoodKey, Foods table with, 207
FoodName, Foods table with, 207
foreach looping construct, 24, 88
For loop, 24–25
For loop statements, commas in, 25–26
Format conversion, classes used for, 48–51
Format method, 29
Form Designer, 258
Form feed ( f), 15
Form initialization method, 194, 295
Form_Load routine, 247
Form object, 259
Form1 class, simple hello window in, 65
Forms, menus added to, 39
Fortran, 19
Fowler, M., 81
FoxBase, 202
Friend construction (C++), 302
ftx delegate, 60
G
Gamma, Eric, 4
Garbage collection, and managed languages, 30
Garden class, 116
Gardener program
major objects in, 117
user interface of, 117
Garden interface, 116
GardenMaker factory, 115–120
and handling RadioButton and Button events, 119–120
PictureBox, 118–119
Garden object, methods in, 118
GardenPic class. from PictureBox, 118
Gestalt, 3
getBuilder method, 133
getChain method, 244
getChild operation, 180
getClass method, 100
getConvTemp method, 47
getEnumerator method, 289
getFrname method, 102
GetHashCode property, 309
getIterator method, 285
getLname method, 102
Get property, and Rectangle class, 306
getSalaries() method, 181, 184
getSeeding method, 109
getSelected method, 136
getSubordinates method, 283
getSwimmers method, 111
getVacationDays method, 361
getVacDays function, 356
getValue method, 215
getWindow method, with Investment Tracker, 130
gif files, and Buttons, 37
Global points of access, to Singletons, 126
“God class,” Mediator as, 298, 335
GoF patterns, 99
Grand, 81
Graphical editor, state of, 321
Graphics, in C#, 66–67
Graphics object, 68
Greater than operator ((>), 21
Greater than or equal to operator (>=), 21
Green radio button, in watching colors change program, 314
Grid adapter, 166
GridAdapter class, 161
Grocery Database, Price table in, 216
Grocery pricing data, 207, 208
Grocery program, using Façade pattern, 209
Group class, derived from Address class, 129
GUI, 4
Guillamets, 84
H
of color objects, 245
kids clubs in, 288–289
using, 213
in watching colors change program, 316
Hello form, 65
Help chain, simple demonstration, 248
Help command, receiving, 250–251
Help system, programming, 248–251
HiTextBox, instance of on Windows Designer pane of new form, 74
HiTextBox control, 74
new derived and regular TextBox control, 75
HitTest object, 162
“Hollywood Principle,” and Templates, 351
Hysteresis, 263
I
IBM DB/2, 202
ICloneable interface, 149
implemented by SwimData class, 146
IComparable interface, 147, 173
Icon class, 235
Icon files, and Buttons, 37
Icons
adding to toolbox, 257
and Flyweight, 223
IDE. See Integrated development environment
IdictionaryEnumerator, 289
IEnumerator, 181
interface, 284
if clause, 19
if-else case statements, 321
if statement, 19
If tests, 322
if-then-else, 19
Illegal filenames, exceptions for, 94
ImageChain class, 245
Image class, 235
Image control, 234
Image proxy, 234
ImageProxy class, 234
Imager class, 248
Imager object, 234
Images, on Buttons, 37
Implementing the interface, 76
Implementor
in Bridge pattern, 169
VisList interface defines interface of, 173
#include directive, in C and C++, 16
Increment operator (++), 18, 19
in databases, 199
demo of bits gotten from number with, 62
Inheritance, 1, 7, 8, 27, 65–80, 74, 80
abstract classes, 76–78
and adapters, 157
constructors, 65–66
drawing and graphics in C#, 66–67
interfaces, 76
interfaces and abstract classes compared, 79–80
namespaces, 68–71
object, 5
and overloading, 71–72
overriding methods in derived classes, 72–73
overriding Windows controls, 74–75
relationships in Builder pattern, 138
replacing methods using new keyword, 74
representation of, in UML diagram, 83
and UML diagrams, 82–83
using, 68
virtual and override keywords, 72
Initialization, 56
and constructor methods, 65
multiple equal signs for, 16
InitializeComponent method, 35, 66, 67
of classes, 53
and Singleton pattern, 124
Integers, methods for, 29
Integrated development environment, class module created from, 45
Interaction, between objects, 5
Interface manipulation, data manipulation separated from, 45
abstract classes compared with, 79–80
dissimilar classes with same, 150–152
For Iterator, 283
and Observers, 314
and UML diagrams, 84
Interleaved Commands, 263
Internal iterators, external iterators versus, 290
Internalization, and learning design patterns, 6
internal keyword, 302
Internet Explorer, 191
InterpChain class, 279
Interpreter pattern, 8, 239, 269–282
applicability of, 269–270
and Chain of Responsibility pattern, 253
consequences of, 281–282
implementing, 277–280
interpreting the language, 271–272
motivation for, 269
names for participating objects in, 277
objects used in parsing, 272–276
operation of on simple command in text field, 281
program on the CD-ROM, 282
reducing the parsed stack, 276–277
simple parsing hierarchy for, 273
simple report example, 270–271
and syntax tree, 278–280
int type, 14
Investment Tracker, 130–135
CheckChoice class, 133–134
ListboxChoice class, 134–135
StockFactory class, 132–133
is equal to operator (==), 21
isLegal, 275
is not equal to operator (!=), 21
Isosceles triangle, drawing, 349–350, 351
isUndo method, 265
methods for, 39
using in ListBox control, 135–136
Iterator, fetching, 285–286
Iterator code, sample, 284–285
Iterator interface, and KidIterator class, 285
Iterator pattern, 9, 239, 283–290
consequences of, 289–290
and filtered iterators, 286–288
motivation, 283–284
programs on the CD-ROM, 290
sample iterator code, 284–286
and tracking clubs, 288–289
J
Jacobson, Ivar, 81
arrays in line with style used in, 87
C# roots in, 29
differences between C# and, 27
Hashtable, 213
Java Design Patterns: A Tutorial, 4
JPEG files, and Buttons, 37
K
Kelvin temperature scale, converting
to, 47
Keyboard listeners, 250
KeyDown event, 251
KeyDown event listener, 250
Keys
and Hashtable, 213
to Hashtable of color objects, 245
for Price table, 215
Keywords, 43
KidClub class, 287
KidIterator class, 285
Kids class, 285
L
Label control, properties for, 36
Languages
applicability of, 270
and Interpreter pattern, 269
interpreting, 271–272
Language symbols, parsing into tokens, 271
LastFirst class, 101
Layout, in Decorator, 194
Layout managers, 27
Left shift n places (<< n), 18
length property, for arrays, 87
Less than operator (<), 21
Less than or equal to operator (<=), 21
Licensing fees, and embedding of commercial languages, 269
LineButton command Button class, 339–340
Line graphs, 338
plotting, 345
and Strategy pattern, 343
LineGraph strategy, 344
LinePlot class, 345
Line plots, making, 342
LinePlotStrategy class, 340, 341
LinePlot window, 341
class adapter approach to, 165
ListboxChoice class, 134–135
ListBox class, 59, 76, 159, 169
KidList class derived from, 294
MyList derived from, 164–165
properties, 38
ListBox control
Items collection in, 135–136
plotting data with, 136
List boxes
automatic language generation with, 281
food prices loaded into, 218
kidclub, 289
Listbox pattern, 9
ListBox type, 166
Listeners, 250
ListForm observer, 317
List interface, stocks with, 131
List observer, 317
ListObs window, 315
Lists, data moved between, 157–158
Logical AND operator (&&), 21
Logical Not operator (~), 21
Logical Or operator (__), 21
Looping, through arrays, 87
Looping statements, 24
Lowercase, C# syntax in, 11
Lower class, 60
M
Macro language, 269
Macro record button, 281
main function, 17
MainMenu control, 257
adding to window form, 39
Managed languages, and garbage collection, 30
ManagerVisitor, 361
Math computation, factory patterns in, 103–105
Mathematica, 270
Mediator
and command buttons management, 321
and handling of mouse and paint events, 310
interaction between buttons and, 330
StateManager and, 326–328, 329
Mediator class, 294, 296–297, 306, 326
interactions between classes simplified with, 293
Mediator object, interactions between Command objects and, 198
Mediator pattern, 8, 239, 291–299, 311
consequences of, 298–299
example system, 291–292
and initialization of system, 297
interactions between controls, 292–293
looser coupling between classes with, 291
mediators and command objects, 297
program on the CD-ROM, 299
sample code, 294–297
simple program with two lists, two buttons, and text field, 292
and single interface mediators, 299
Mediators, and “god class,” 298, 335
Memento interface, and handling undo list, 331
Memento objects, 302, 307, 308
Memento pattern, 8, 239, 301–312, 327, 331
cautionary note about sample code with, 308–309
and command objects in user interface, 309–310
consequences of, 311
implementation, 302
motivation, 301–302
mouse and paint events handled
with, 310
program on the CD-ROM, 312
purpose of, 301
rectangles drawing pattern demo, 302, 303, 304
roles for objects defined by, 302
sample code, 302–309
UML diagram for drawing program with, 311
MenuBar, 257
Menus adding to form, 39
Metafile class, 235
accessor, 45
Concrete, 347
with Garden object, 118
implementations of and interfaces, 76
for Items Collection, 39
for objects, 29
overriding in derived classes, 72–73
polymorphic, 72
replacing using new, 74
Template, 347
in Template class, 347
virtual, 347
MicroGold, 86
Microsoft Access, 202
Microsoft Excel, 313
Microsoft Office products, VBA in, 269
Microsoft SQL Server, 202
Microsoft Works, 202
Model-View-Controller framework, 3, 4
Modules, class, 45
Modulo operator (%), 18
Mouse, handling in C#, 230
Mouse click events, 323
MouseDown event, 162
Mouse drag events, 323
MouseUp event, 322
move method, 333
moveNext() method, 287
MultiChoice interface, 132
with Investment Tracker, 130
Multiple exceptions, 91–92
Multiple variables, declaring, 14
Multiplication operator (*), 18
MultVar class, 276
MultVar object, 280
MyList class, derived from ListBox class, 164–165
N
NameFactory, 102
Namer Factory program, 102
Namer program, execution of, 103
Narrower data types, and wider data types, 13
.NET
composites in, 189
Visual control, 176
Netscape Navigator, 191
new keyword, methods replaced using, 74
Newline (line feed) character ( n), 15
new operator, 97
New Project selection window, 31
nextToken method, 52
nextTop method, 271
NoCmd Chain element, 246
NoCmd class, 248
Node object class, 189
NonTerminal Expression, 280
NonTerminalExpression object, in Interpreter pattern, 277
Nonvisual decorators, 197
Normal form, 200
Notification messages, and Observer pattern, 318
NOT operation, 17
Null character ( 0), 15
Null exceptions, 94
null reserved word, 14
Numbers, converting between strings and, 13–14
Numerical types, conversion from, 29
Numeric constants, 14
O
Object adapters, 157
class adapters versus, 166
Object Database Connectivity, 202–203
Object-oriented approaches, notes on, 7–8
Object-oriented languages, and
signatures, 71
Object-oriented programming, 1, 8
and design patterns, 4
difference between procedural programming and, 53
factory concept in, 107
template patterns in, 352
Object patterns, class patterns versus, 155
in C#, 29
and Chain of Responsibility pattern, 242
classes as, 53–54
and creational patterns, 97
interaction between, 5
saving state of, 302
used in parsing, 272–276
Objects class, 31
object type, objects fetched from ArrayList and, 88
Observer interface, 315
Observer pattern, 239, 242, 299, 313–319
candidate for, 317
consequences of, 318–319
data displayed as list and in graphical mode, 313
and message to the media, 318
program on the CD-ROM, 319
simple control panel to create red, green, or blue “data,” 314
UML diagram of observer interface and subject interface implementation of, 317
and watching colors change, 314–317
Observers
notification messages sent to, 318
and Observer pattern, 314
update methods to, 319
in watching colors change program, 315, 316, 317
ODBC. See Object Database Connectivity
OleDbAdapter, 220
OleDbCommandBuilder, 220
OleDbCommand class, 203
OleDbCommand object, 205
OleDbConnection, 220
OleDbConnection object, 203
OleDbDataAdapter, 203
One’s complement (~), 18
OneSexSwimData class, displaying with one sex on the right, 148
OpenCommand class, 261
OpenForRead statement, 95
OpenForWrite() method, 96
OpenForWrite statement, 95
OpenMenu class, 257
open method, 204
Oracle, 202
Ordering components, and Composite pattern, 189
Organizational chart, typical, 180
Origin, 270
Originator class, 311
Originator object, and Memento pattern, 302
OR operation, 17
Output, 270
override keyword, 72
P
Paint Event, selecting for PictureBox window, 67
PaintEventArgs object, 67
PaintEventHandler, 194
Paint events, 66, 118, 193, 310
and Decorator interface, 192
handling in C#, 230
in watching colors change program, 315
Paint handler, 266
Paint routine, bar plot drawn in, 341
Parentheses ()
around conditions, 19
data type names enclosed in, 13
and switch statement, 22
Parsed stacks, reducing, 276–277
ParseObject class, 272
ParseObjects, 281
Parser class, 274–275, 277, 280
ParseVar class, 275
ParseVar object, 273
ParseVerb class, 275
ParseVerb object, 273
Parsing, 49
interaction of classes performing, 278
objects used in, 272–276
Parsing hierarchy, for Interpreter pattern, 273
Pascal, 19
Pattern groupings, 311
Pattern Hatching (Vlissides), 361
“Pattern mining,” 6
Peek method, 95
Pens, and Paint method, 194
PerennialGarden class, 117
Person, instances of in Company, 84
Person class, 81
derived from Address class, 129
and inheritance, 82–83
with private, protected, and public variables, and methods, 82
UML diagram for with/without method types, 82
pic_Paint event handler, 347
picPaint handler, 230
PictureBox
control, 316
inserting on a Form, 66
Picturebox level, mouse motion checked at, 229
PictureBox window, Paint Event selected for, 67
Pie charts, 338
Placeholder classes, and template classes, 352
Plant object, 116
Plot click method, 136
PlotPanel class, 347
Plots, drawing in C#, 341
PlotStrategy class, 344
instances of, 338
PlotWindow class, 345
Pluggable adapters, 166
Plus sign (+), to combine strings, 17
Polymorphic methods, 72
pop method, 271
Positioner class, 227
Prefix characters, and numeric constants, 14
Prefixes, 58
PrelimEvent class, 108, 109, 110, 112
PriceKey, Price table with, 207
Price query, building, 207–208
building, 215–218
in Grocery Database, 216
PRINT, 273
Print object, 273
PrintSpooler class, writing skeleton of, 125
Private methods, 48, 53, 63, 71
Privileged access
and Iterator pattern, 290
and Memento pattern, 301
Process button, 60
Product class, 170
ProductList class, 173
Product objects, 173, 174, 175
ProductTable class, 173
ProductTable version, of VisList, 172
Programming, object-oriented, 1
Programming style, in C#, 58
Programs
on CD-ROM, 41, 63, 80, 106, 113, 121, 127, 139, 154, 167, 177, 190, 198, 221, 232, 237, 253, 268, 282, 299, 312, 319, 336, 344, 352, 363
interpreters introduced into, 281
Mediator and changes in behavior of, 298
Seeding, 111–112
simple C#, 16–17
simplest Window, in C#, 32–34
simple temperature conversion, 43–45
triangle drawing, 350–351
undoable, 264
watching colors change, 314–317
Windows Controls, 40–41
Properties, classes and, 56–58
Properties window, 66
MouseMove event selected from, 231
protected keyword, 71
Protected methods, 71
Protected variables, 71
Prototype, re-sort of left list box shown with, 146
Prototype managers, 152–153
Prototype pattern, 98, 141–154, 154
and cloning in C#, 142
and cloning the class, 146–147
consequences of, 153
and prototype managers, 152–153
Prototype program
simple, 145
sorted results of, 145
Prototype Registry, 153
Proxy image display, with image load shown, 236
comparison with related patterns, 237
program on the CD-ROM, 237
proxies in C#, 236
sample code, 234–236
use of, 233–234
Public methods, 48, 53, 63, 71
push method, 271
Q
Queries, executing in ADO.Net, 205
Queue object, 90
Queuing of commands, 257
QuickImage class, 235
Quit key, 248
Quotes (’), characters enclosed in, 14
R
Radio button events, handling, 119
Radio buttons (or option buttons), 37, 281
Reading
opening file for, 96
text files, 93
readLine method, 96
Recognition, and learning design
patterns, 6
Rectangle
drawing in PictureBox on form, 66
square created from, 69–71
Rectangle button, 302, 307, 321
Rectangle class, 68, 77, 229, 306
DoubleRect class derived from, 72, 73
instance of, 69
Square class derived from, 69–70, 71
Rectangle drawing program, 69
Rectangle state object, 324
command class, 310
Command objects for, 309
Rect button, behavior of, 323
rects property, 333
RectState object, 324
Red button, 260
RedButton class, 257
Red menu item, 260
Red radio button, in watching colors change program, 314
References, to arrays, 88
Refined abstraction, in Bridge pattern, 169
registerInterest method, 314
Registry
of Prototype classes, 153
and Singleton instantiation, 126
Relational database, 270
repaint method, 347
Report Generators, 270–271
Responsibilities, Decorator pattern and, 198
Right shift n places (>>n), 18
Rows, 199
adding to database tables using ADO.Net, 206–207
editing or deleting, 207
Row selection, detecting, 162
Rumbaugh, James, 81
S
Salaries computation, 180–181
SalaryType column, data in, 200
Scott, K., 81
Second normal form (2NF), tables in, 200
Seeding class, 108
Seeding diagram, Seeding interface and derived classes in, 109
select case statements, 321
SelectedIndex property, 162
Selected instance, of Folder, 228, 229
SelectIndexChanged event, 295
Select method, and Mediator, 295
selectOne method, added to State interface, 324
Select tests, 322
Self-promotion, and Composite pattern, 186–187
Semicolon (;)
C# statements terminating with, 11
at end of declaring draw method as abstract, 77
statements terminating with, 17
Sender class, 248
Sequential operations, languages and specifying order of, 281
setBounds method, 341
setFill method, 333
setPenColor method, 344
setPlotBounds(), 341
Set property, and Rectangle class, 306
setSelected method, 333
setText method, 295
SexSwimData class, 148, 149, 151
Shallow copy, 147
Shape objects, 78
Sharable objects, 231–232
Simonyi, Charles, 58
SimpleComposite example, 188–189
Simple Factory pattern, 97, 99
building, 101–103
sample code, 100
two derived classes, 100–101
workings of, 99–100
SimpleHello form, after clicking Say Hello button, 33
Single interface Mediators, 299
Single quote ( ’), 15
SingletonException:Exception class, 124
Singleton pattern, 8, 9, 98, 123–127, 154
consequences of, 126
and creating instance of the class, 125–126
and creating singleton using static method, 123–124
exceptions and instances, 124
global point of access provided to singletons, 126
and throwing the exception, 125
SlashDecorator, CoolButton decorated with, 196
Model-View-Controller framework for, 3
Smalltalk Companion. See Design Patterns Smalltalk Companion
SORT, 273
SortBridge class, 173
sorted list generated using, 175
SortedList class, 89–90
Sort object, 273
Special characters, representations of, 15
Split method, of String class, 51
SQL. See Structured Query Language
SQL query, and ADO.NET Façade, 209, 211
SQL-92 standard, 202
Square, creating from rectangle, 69–71
Square class, deriving from Rectangle class, 69–70, 71
Stack class, 271
Stack object, 90
Stack reduction, and syntax tree, 278
Stacks, 271
ParseObject pushed onto, 272
reducing during parsing, 276
State, of graphical editor, 321
State interface, selectOne method added to, 324
StateManager, 326–328
and the Mediator, 329
StateManager class, 323
current state tracked by, 324
and switches between states, 325–326
State object, mouse activities handled by, 323, 324
State pattern, 8, 239, 309, 321–336
consequences of, 335–336
Fill state handled with, 330–331
and Mediator interaction with State Manager, 326–329
Mediators and “god class,” 335
program on the CD-ROM, 336
sample code, 321–325
simple drawing program illustrating, 322
and state transitions, 336
and Strategy pattern, 337
and switching between states, 325–326
undo list handled with, 331–333
using, 321
VisRectangle and VisCircle classes, 333–335
State transitions, and State pattern, 336
Static methods
in File object, 92
and global point of access, 126
singleton created with, 123–124
Static variable, 123
StockFactory class, 132–133
Stocks, with list interface, 131
Stocks:Equities class, 132
Store class, derived from DBTable, 213
StoreFoodPrice objects, and Prices class, 215
StoreKey, Stores table with, 207
StoreName, Stores table with, 207
Straight seeding
of 500 free, 112
of swimmers, 107
StraightSeeding class, 110, 111
StraightSeeding subclass, 108, 109
Strategy pattern, 239, 337–344, 345
consequences of, 344
and Context class, 339
and drawing plots in C#, 341–342
line and bar graph strategies, 340
motivation, 337–338
program commands, 339–340
program on the CD-ROM, 344
sample code, 338
simple panel to call different plots, 340
UML diagram of, 343
StreamReader object, 93
StreamWriter object, 93
String class, Split method of, 51
string object, 31
StringTokenizer class, 51–52, 55, 56, 71–72, 142, 271, 274
struct types, 26
Structural patterns, 6, 97, 155–237
Adapter, 157–167
Bridge, 169–177
Composite, 179–190
Decorator, 191–198
Façade, 199–221
Flyweight, 223–232
Proxy, 233–237
summary of, 237
Structural programs, summary of, 237–238
Structured Query Language, 202, 270
and Abstract Factory pattern, 120
of DrawObject, 353
of InterpChain, 280
and interpret operation, 279
and Prototype pattern, 148, 152, 153
and Singleton, 126
and Template pattern, 345
and visitor classes, 360
Subject, and Observer pattern, 314
Subject interface, 314
Subjects, observers and abstract coupling to, 318
Subordinates, ArrayList, 188
subordinates method, 182
Subsystems, and Façade pattern, 199, 220
Subtraction operator (-), 18
Suffix characters, and numeric constants, 14
Superclasses, 107
UML diagram for, 152
SwimInfo class, 151
Swimmer class, 53, 54, 55, 56–58, 109, 142
Swimmers, straight seeding of, 107
SwimmerTimes display program, revised version of, 56
Sybase, 202
Symbols, in UML diagrams, 82
Syntax tree, and parsing of stack, 278–280
System.Collections namespace, 88
System.Drawing namespace, 68, 229
T
Tab character ( t), 15
classes for in Façade pattern, 213–215
deleting contents of, in ADO.Net, 205–206
employee names and salary type, 200
building, 45–47
decisions put into, 47–48
Temperature conversion program, simple, 43–45
Template class, methods in, 347
Template Method pattern, 239, 345–352
consequences of, 352
kinds of methods in Template class, 347
motivation, 345–347
programs on the CD-ROM, 352
sample code, 347–350
templates and callbacks and, 351–352
Triangle drawing program, 350–351
Template methods, 347
Template pattern
and abstract Triangle class, 348
using, 345
Templates, 345
temp variable, 47
TerminalExpression, 280
TerminalExpression object, in Interpreter pattern, 277
Ternary operator, 23
Testing, for end of file, 94–95
Text, and changes in label, 40
TextBox control, 74
and new derived HiTextBox control, 75
TextBoxes, 189
TextBox properties, 37
Text comments, in UML diagrams, 85
Text data, and different line-breaking strategies, 338
Text files
reading, 93
writing, 93–94
Text property, 36
Third normal form (3NF), tables in, 200, 201
Third-party products, VBA embedded in, 269
Throwing exceptions, 92
throws keyword, 27
Throw statement, 92
TimedFinalEvent class, 108, 109, 110, 112
Time entry interface, with parsing of symbols for Scratch, Disqualification, and No Time, 50
TimerCallback class, 234
timerCall method, 234
Timer class, 234
Times class, 55
simple parsing program using, 49
TimeSwimData class, 151
Tokenizer class, 51–52
Tokenizer demo, 53
Tokens
parsing language symbols into, 271
strings separated into, 51
ToolbarButtons, in C#, 309
Toolbox
new control shown on, 74
TextBox selected from, 33
top method, 271
TPaint method, 351
Tree adapter, 166
TreeDemo program, 164
Tree list component, and Bridge, 176
Tree list display, of composite with display of parent nodes, 188
TreeView control, corporate organization shown in, 186
TreeView list, 185
TreeView pattern, 9
draw code in, 351
three subclasses of, 348
Triangle drawing program, 350–351
TriangleForm class, 350
Triangles
drawing isosceles, 349–350, 351
TrigButterfly class, 105
and exceptions, 90
file manipulation code enclosed in, 94
Two-way adapters, 166
Type checking, and registry approach, 126
U
UML. See Unified Modeling Language
and annotation, 85–86
for Bridge pattern, 173
of Chain of Responsibility program class structure, 247
of CommandHolder approach, 262
and composition, 84–85
for Decorators, 197
for drawing program using Memento, 311
and inheritance, 82–83
of inheritance relationships in Builder pattern, 138
and interfaces, 84
of observer interface and subject interface implementation of Observer pattern, 317
showing Employee derived from Person, 83
of Strategy pattern, 343
for various SwimData classes, 152
WithClass, 86
UndoButton, 302
Command objects for, 309
and rectangles drawing program with Memento, 302, 304
Undo command demo
program drawing red and blue lines, 263
program drawing red and blue lines after Undo button clicked, 264
UndoCommand object, 265
Undo commands, 301
Undo function, with Command patterns, 262–267
unDo list
handling, 331–333
unDo method, 265
Undo program, classes implementing in Command pattern implementation, 267
Undo requests, 257
Unicode, 12
Unified Modeling Language, 81
Unreasonable values, handling, 51
Unsafe blocks, 26
Unsafe mode, 27
Unsafe sections of C# code, pointers used within, 62
Unselected instance, of Folder, 228, 229
User commands, command interpreter for parsing, 270
User interfaces, command objects in, 309–310
using statement, 16
V
Vacation data
for bosses, 359
for employees, 356–359
Vacations button, 359
VacationVisitor class, 356
Value conversion, classes used for, 48–51
value keyword, 56
Value method, 289
declaring as public, private, and protected, 71
declaring as they are used, 15–16
delegate, 59
protected, 71
static, 123
VAR type, 273
VarVarParse class, 280
VBA. See Visual Basic for Applications
VB.NET
and C#, 29
as managed language, 30
VB7, 30
VeggieGarden class, 116
VERB type, 273
Video data capture, and compression schemes, 338
View, 4
virtual keyword, 72
Virtual methods, 347
Visiting, meaning of, 354
triangle classes visited by, 354
Visitor object, 355
and Boss visits, 359
catch-all operations with visitors, 360–361
consequences of, 362
and double dispatching, 361
motivation, 353–355
program on the CD-ROM, 363
sample code, 355–356
times to use, 355
traversing series of classes and, 362
using, 353
vacation visits demo, 360
visit and accept methods interactions, 354
visiting several classes, 357–358
visiting the classes, 357
Visitors, catch-all operations with, 360–361
VisList interface, 173, 175, 176
VisList variable, 171
VisRectangle class, 304, 305–306, 333–335
Drawing interface implemented by, 333
VisCircle inheriting from, 333, 335
VisRectangle instance, 306
Visual Basic, 19
C# roots in, 29
major differences between C# and, 11
Visual Basic Design Patterns: VB6 and VB.NET, 4
Visual Basic for Applications, 269
Visual Basic.NET, 11
Visual command interpreter program sample, Chain of Responsibility pattern, 243
Visual controls, interactions between, 292–293
Visual Studio IDE, and mouse move event handler, 230
Visual Studio.NET, 20, 31, 32, 86, 203
decorating inner class in, 197
grid table with, 160
Integrated Development Environment, 65
namespaces, 68
screen from, showing properties interface, 176, 177
visual builder in, 44
Vlissides, J., 361
W
WealthBuilder class, 135
WealthBuilder program, with list of equities, list box, check
boxes, and plot panel, 137
Web sites, for learning design patterns, 7
While loop, 24
White space characters, 14
representations of, 15
Wider data types, and narrower data types, 13
Windows
and data display, 313
and ODBC, 203
Buttons, 37
CheckBox, 36–37
Items collection, 38–39
labels, 35
ListBoxes and ComboBoxes, 38
menus, 39
overriding, 74–75
radio buttons, 37
selection of basic, 35
TextBox, 36
ToolTips, 39–40
Windows Controls program, 40–41
Windows Designer, 74
in Visual Studio.NET, 32
Windows Form class, 35
Windows Form Designer, 230
Windows.Forms library, 33
WithClass UML diagrams, 86
writeLine function, 17
writeLine method, 96
Writing text files, 93–94
Writing Windows C# programs, 29–41
building a C# application, 31–32
classes and namespaces in C#, 30–31
managed languages and garbage collection, 30
objects in C#, 29
simplest Window program in C#, 32–34
Windows controls, 35–40
Windows controls program, 40–41
X
XFactory class, 100
XML, and ADO.NET, 203