Practical C++ Design: From Programming to Architecture

257 Pages·2017·2.37 MB·English

by  Adam B. Singer

Practical
C++ Design
From Programming to Architecture
—
Adam B. Singer
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Practical C++ Design
From Programming to Architecture
Adam B. Singer
WOW! eBook
www.wowebook.org
Practical C++ Design: From Programming to Architecture
Adam B. Singer
The Woodlands, Texas, USA
ISBN-13 (pbk): 978-1-4842-3056-5 ISBN-13 (electronic): 978-1-4842-3057-2
DOI 10.1007/978-1-4842-3057-2
Library of Congress Control Number: 2017954981
Copyright © 2017 by Adam B. Singer
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Table of Contents
About the Author �����������������������������������������������������������������������������������������������������xi
About the Technical Reviewer �������������������������������������������������������������������������������xiii
Preface ��������������������������������������������������������������������������������������������������������������������xv
Chapter 1: Defining the Case Study ��������������������������������������������������������������������������1
1.1 A Brief Introduction ................................................................................................................1
1.2 A Few Words About Requirements .........................................................................................2
1.3 Reverse Polish Notation .........................................................................................................3
1.4 The Calculator’s Requirements ..............................................................................................5
1.5 The Source Code ....................................................................................................................6
Chapter 2: Decomposition ����������������������������������������������������������������������������������������9
2.1 The Elements of a Good Decomposition ..............................................................................10
2.2 Selecting an Architecture .....................................................................................................12
2.2.1 Multi-Tiered Architecture .............................................................................................12
2.2.2 Model-View-Controller (MVC) Architecture ..................................................................14
2.2.3 Architectural Patterns Applied to the Calculator ..........................................................15
2.2.4 Choosing the Calculator’s Architecture .......................................................................16
2.3 Interfaces .............................................................................................................................17
2.3.1 Calculator Use Cases ...................................................................................................18
2.3.2 Analysis of Use Cases ..................................................................................................21
2.3.3 A Quick Note on Actual Implementation ......................................................................27
2.4 Assessment of Our Current Design ......................................................................................28
2.5 Next Steps ............................................................................................................................28
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Table of ConTenTs
Chapter 3: The Stack ����������������������������������������������������������������������������������������������31
3.1 Decomposition of the Stack Module ....................................................................................31
3.2 T he Stack Class ....................................................................................................................34
3.2.1 The Singleton Pattern ..................................................................................................34
3.2.2 The Stack Module as a Singleton Class .......................................................................36
3.3 A dding Events ......................................................................................................................40
3.3.1 The Observer Pattern ...................................................................................................41
3.3.2 The Stack as an Event Publisher .................................................................................52
3.3.3 The Complete Stack Interface .....................................................................................53
3.4 A Quick Note on Testing .......................................................................................................54
Chapter 4: The Command Dispatcher ���������������������������������������������������������������������57
4.1 Decomposition of the Command Dispatcher ........................................................................57
4.2 T he Command Class ............................................................................................................58
4.2.1 The Command Pattern .................................................................................................58
4.2.2 More on Implementing Undo/Redo ..............................................................................59
4.2.3 The Command Pattern Applied to the Calculator .........................................................61
4.3 T he Command Repository ....................................................................................................81
4.3.1 The CommandRepository Class ...................................................................................81
4.3.2 Registering Core Commands .......................................................................................87
4.4 The Command Manager .......................................................................................................88
4.4.1 The Interface ...............................................................................................................88
4.4.2 Implementing Undo and Redo .....................................................................................89
4.5 The Command Dispatcher ....................................................................................................91
4.5.1 The Interface ...............................................................................................................92
4.5.2 Implementation Details ...............................................................................................93
4.6 Revisiting Earlier Decisions .................................................................................................95
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Chapter 5: The Command Line Interface ����������������������������������������������������������������97
5.1 T he User Interface Abstraction .............................................................................................97
5.1.1 The Abstract Interface .................................................................................................98
5.1.2 User Interface Events ................................................................................................101
5.2 The Concrete CLI Class ......................................................................................................105
5.2.1 Requirements ............................................................................................................105
5.2.2 The CLI Design ...........................................................................................................107
5.3 Tying It Together: A Working Program ................................................................................112
Chapter 6: The Graphical User Interface ���������������������������������������������������������������115
6 .1 R equirements .....................................................................................................................115
6.2 B uilding GUIs ......................................................................................................................118
6.2.1 B uilding GUIs in IDEs .................................................................................................119
6.2.2 Building GUIs in Code ................................................................................................120
6.2.3 Which GUI Building Method Is Better? .......................................................................121
6.3 M odularization ...................................................................................................................122
6.3.1 T he CommandButton Abstraction ..............................................................................122
6.3.2 T he CommandButton Design .....................................................................................123
6.3.3 T he CommandButton Interface ..................................................................................127
6.3.4 G etting Input ..............................................................................................................129
6.3.5 T he Design of the InputWidget ..................................................................................129
6.3.6 The Interface of the InputWidget ...............................................................................131
6.4 T he Display.........................................................................................................................132
6.4.1 The Design of the Display Class ................................................................................134
6.4.2 A Poor Design ............................................................................................................134
6.4.3 An Improved Display Design ......................................................................................135
6.5 T he Model ..........................................................................................................................136
6.6 T he Display Redux ..............................................................................................................138
6.7 Tying It Together: The Main Window ...................................................................................139
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6.8 L ook-and-Feel ....................................................................................................................141
6.9 A Working Program ............................................................................................................142
6.10 A Microsoft Windows Build Note ......................................................................................144
Chapter 7: Plugins ������������������������������������������������������������������������������������������������145
7.1 What Is a Plugin? ...............................................................................................................145
7.1.1 Rules for C++ Plugins ...............................................................................................146
7.2 Problem 1: The Plugin Interface .........................................................................................149
7.2.1 The Interface for Discovering Commands .................................................................149
7.2.2 The Interface for Adding New GUI Buttons ................................................................154
7.2.3 P lugin Allocation and Deallocation ............................................................................156
7.2.4 T he Plugin Command Interface .................................................................................156
7.2.5 A PI Versioning ............................................................................................................159
7.2.6 M aking the Stack Available .......................................................................................160
7.3 Problem 2: Loading Plugins ...............................................................................................161
7.3.1 P latform-Specific Plugin Loading ..............................................................................162
7.3.2 Loading, Using, and Closing a Shared Library ...........................................................162
7.3.3 A Design for Multi-Platform Code ..............................................................................164
7.4 Problem 3: Retrofitting pdCalc ...........................................................................................177
7.4.1 M odule Interfaces ......................................................................................................178
7.4.2 Adding Plugin Buttons to the GUI ...............................................................................182
7.5 I ncorporating Plugins .........................................................................................................183
7.5.1 L oading Plugins .........................................................................................................184
7.5.2 I njecting Functionality ...............................................................................................185
7.6 A Concrete Plugin ...............................................................................................................187
7.6.1 P lugin Interface .........................................................................................................187
7.6.2 S ource Code Dependency Inversion ..........................................................................189
7.6.3 I mplementing HyperbolicLnPlugin’s Functionality .....................................................190
7.7 N ext Steps ..........................................................................................................................193
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Chapter 8: New Requirements ������������������������������������������������������������������������������195
8.1 F ully Designed New Features ............................................................................................195
8.1.1 B atch Operation .........................................................................................................196
8.1.2 S tored Procedures .....................................................................................................197
8.2 Designs Toward a More Useful Calculator ..........................................................................211
8.2.1 C omplex Numbers .....................................................................................................211
8.2.2 V ariables ....................................................................................................................216
8.3 Some Interesting Extensions for Self-Exploration ..............................................................221
8.3.1 H igh DPI Scaling ........................................................................................................221
8.3.2 D ynamic Skinning ......................................................................................................221
8.3.3 F low Control...............................................................................................................222
8.3.4 A n Alternative GUI Layout ..........................................................................................222
8.3.5 A Graphing Calculator ................................................................................................222
8.3.6 A Plugin Management System ...................................................................................223
8.3.7 A Mobile Device Interface ..........................................................................................223
Appendix A: Acquiring, Building, and Executing pdCalc ���������������������������������������225
A .1 Getting the Source Code ....................................................................................................225
A.2 D ependencies ....................................................................................................................225
A.3 B uilding pdCalc ..................................................................................................................226
A.3.1 U sing Qt Creator ........................................................................................................227
A.3.2 Using the Command Line ..........................................................................................228
A.4 E xecuting pdCalc ...............................................................................................................229
A.4.1 U sing Qt Creator ........................................................................................................229
A.4.2 Using the Command Line ..........................................................................................229
A.5 T roubleshooting .................................................................................................................230
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Appendix B: Organization of the Source Code ������������������������������������������������������233
B.1 T he src Directory ................................................................................................................233
B.1.1 T he pdCalc Directory .................................................................................................233
B.1.2 T he pdCalc-simple-cli Directory ................................................................................234
B.1.3 T he pdCalc-simple-gui Directory ...............................................................................234
B.1.4 T he utilities Directory ................................................................................................234
B.1.5 T he backend Directory ..............................................................................................234
B.1.6 T he cli Directory ........................................................................................................235
B.1.7 T he gui Directory .......................................................................................................236
B.1.8 T he plugins Directory ................................................................................................236
B.2 T he test Directory ..............................................................................................................236
B.2.1 T he testDriver Directory ............................................................................................237
B.2.2 T he utilitiesTest Directory ..........................................................................................237
B.2.3 T he backendTest Directory ........................................................................................237
B.2.4 T he cliTest Directory ..................................................................................................238
B.2.5 T he guiTest Directory .................................................................................................238
B.2.6 T he pluginsTest Directory ..........................................................................................238
References ������������������������������������������������������������������������������������������������������������239
Index ���������������������������������������������������������������������������������������������������������������������243
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