Cross Platform Objective C Development Using Gn Ustep
- 2. What is Objective-C ? it is a programming language
- 3. it is a strict superset of C it is C with some new additional constructs
- 4. C code compiles as Objective-C code
- 5. C libraries can be linked and used natively from Objective-C it adds Object-Oriented features to C Defining classes
- 7. Instantiating classes and objects
- 8. Invoking class and object methods
- 9. Protocols, categories, selectors, forwarding
- 10. Example of Objective-C Code
- 11. Why is Objective-C so special ? It is compatible with C libraries
- 12. Is is a simple extension of C
- 13. It is a hybrid between C and Smalltalk It can be as fast as raw C if you avoid the object-oriented extensions
- 14. It can be as high-level and flexible as Smalltalk if you use the object-oriented extensions
- 15. It allows experienced programmers to mix different programming styles in the same program It is extremely flexible
- 16. Objective-C Support Compilers Apple GCC
- 17. FSF GCC Objective-C 2.0 Introduced by Apple in
- 18. Mac OS X 10.5
- 21. Fast Enumeration
- 22. Properties
- 23. Objective-C 1.0 code still compiles with a 2.0 compiler Runtime Libraries NeXT/Apple Runtime
- 24. GNU Runtime Core Objective-C Libraries Apple Cocoa
- 25. GNUstep
- 26. Writing Portable Objective-C Code On Apple Mac OS X , avoid Objective-C 2.0 syntax such as properties and fast enumerations. On Apple Mac OS X , avoid garbage collection and use explicit the traditional OpenStep reference counting. This is likely to change – GNUstep is getting garbage collection again. On both Apple and GNUstep , If you need to access the runtime, use an intermediate layer such as the one provided by gnustep-base additions.
- 27. History of Objective-C Core Frameworks
- 28. OpenStep API Specification (1994)
- 29. OpenStep API Specification (1994) Foundation Kit Non-graphical classes Root classes : NSObject, NSProxy
- 30. Basic data classes : NSString, NSNumber, NSData, NSNull
- 31. Collection classes : NSArray, NSDictionary, NSSet
- 32. Execution control classes : NSRunLoop, NSTimer, NSThread, NSLock
- 33. I/O classes : NSTask, NSFileHandle
- 34. Notification classes: NSNotification, NSDistributedNotification
- 35. Serialization classes: NSArchiver, NSCoder
- 36. Resource management classes: NSBundle, NSUserDefaults
- 37. Distributed Objects Classes: NSConnection, NSPort
- 38. And many more... Application Foundation Kit Application Kit Operating System OS Graphical System Objective-C Runtime
- 39. OpenStep API Specification (1994) Application Kit Graphical classes Window classes : NSWindow, NSPanel
- 40. Menu classes : NSMenu, NSMenuItem
- 41. Basic drawing classes : NSView, NSColor, NSFont, NSGraphicsContext
- 42. Basic interaction classes: NSEvent, NSResponder, NSControl, NSCell
- 43. Control classes : NSButton, NSTextField, NSBrowser, NSPopUpButton, NSMatrix
- 44. Table classes: NSTableView
- 45. Text classes : NSTextView, NSTextStorage, NSLayoutManager, NSInputManager
- 46. Scrolling classes: NSClipView, NSSplitView, NSScrollView,
- 47. Standard panel classes: NSFontPanel, NSSavePanel
- 48. And many more... Application Foundation Kit Application Kit Operating System OS Graphical System Objective-C Runtime
- 49. Apple Cocoa Application Cocoa Foundation Kit Cocoa Application Kit Operating System (Apple Darwin/BSD) OS Graphical System Apple Objective-C Runtime
- 50. GNUstep Application GNUstep Base GNUstep GUI Operating System (Any!) Graphical System (Any!) GNU Objective-C Runtime GNUstep Back
- 53. OpenSolaris, HP UX, other Unix systems
- 54. Microsoft Windows Apple Cocoa: Apple Mac OS X
- 55. Writing Portable Objective-C Code On Apple Mac OS X , avoid Apple-only frameworks such as CoreFoundation, CoreSound, CoreAnimation, KeyChain, Carbon, Quartz, Quicktime, WebKit. On GNUstep , avoid GNUstep extensions that are not available as a separate library or framework that works on Apple as well.
- 56. Foundation Kit Example #import <Foundation/Foundation.h> int main (void) { NSLog (@“Hello world!”); return 0; } A (Trivial) Portable Objective-C Program File hello.m:
- 57. Building the Foundation Kit Example On Apple Mac OS X , there is XCode Only for Apple Mac OS X
- 59. It uses its own files
- 60. Hard to work with developers who use other platforms where Xcode is not available
- 61. Building the Foundation Kit Example On GNUstep , there is Project Center Works everywhere
- 62. Similar to XCode
- 63. Lagging in features (this might change)
- 64. Uses its own files, then generates
- 66. to build
- 67. Building the Foundation Kit Example On GNUstep , there is also gnustep-make Works everywhere,
- 68. even without a GUI
- 69. Makefile library designed to make building complex projects easy
- 70. Official building system for GNUstep
- 71. Very complete
- 72. Editable, portable text files
- 73. Requires editing text files - not a point-and-click GUI IDE include $(GNUSTEP_MAKEFILES)/common.make TOOL_NAME = hello hello_OBJC_FILES = hello.m include $(GNUSTEP_MAKEFILES)/tool.make
- 74. Building the Foundation Kit Example Not Portable Portable GUI IDE Text files include $(GNUSTEP_MAKEFILES)/common.make TOOL_NAME = hello hello_OBJC_FILES = hello.m include $(GNUSTEP_MAKEFILES)/tool.make XCode Project Center gnustep-make Pbxbuild can generate GNUmakefiles from Xcode projects
- 75. More Foundation Kit Portability Issues Loading and locating resources and files Windows paths
- 76. Unix filesystem layout => Always use the OpenStep API (NSBundle, NSPathUtilities)
- 77. Tools with Resources (GNUstep) are not available on Apple Frameworks vs Shared libraries Frameworks are shared libraries with resources
- 78. Apple has native linker implementation, GNUstep emulates them
- 79. Emulation can be inefficient/inappropriate on some platforms
- 80. Even More Foundation Kit Portability Issues #ifdef GNUSTEP /* GNUstep-specific code */ #else /* Apple-specific code */ #endif #ifndef GNUSTEP # include “GNUstep.h” #endif Platform-dependent Code User GNUSTEP preprocessor define, which is defined on GNUstep but not on Apple GNUstep macros ASSIGN, RELEASE, etc
- 81. Use GNUstep.h (eg, from Renaissance)
- 82. Application Kit Programs If you create your GUI using the OpenStep API, it's pretty much the same ... ... buttons[0] = [[NSButton alloc] initWithFrame: NSMakeRect (77, 3, 34,24)]; [buttons[0] setButtonType: NSToggleButton]; [buttons[0] setTitle: @"0"]; [buttons[0] setTag: 0]; [buttons[0] setState: NO]; [buttons[0] setAction: @selector(digit:)]; [buttons[0] setKeyEquivalent: @"0"]; ... PS: most developers don't use the OpenStep API directly but use Xcode or Gorm or Renaissance. We'll look at these tools later.
- 83. Menu Portability (hard) On Apple you must use the Apple-only method NSApplication -setAppleMenu: which is not part of OpenStep and not even declared in a public header (!!).
- 84. Menu Portability (hard) On Apple you need to use a goofy private Apple-only setup.
- 85. On GNUstep and Apple the standard organization of menus (location of menu items, etc) are very different.
- 86. Example: Gomoku.app http://www.gnustep.it/nicola/Applications/Gomoku A small game , originally for GNUstep only
- 87. It uses only the OpenStep API
- 88. It creates all the GUI in code
- 89. It has separate code to create the menu
- 90. on Apple Cocoa and GNUstep
- 91. It has a GNUmakefile and is built
- 92. using gnustep-make You can use it as an example of how to build a portable GUI in code .
- 96. Creating GUIs without code On Apple Mac OS X , there is Interface Builder Only for Apple Mac OS X
- 97. Brilliant tool, extremely usable
- 98. and fast
- 99. It uses its own files (“Nib”s)
- 100. NIB files serialize GUI objects,
- 101. including platform-specific attributes such as fonts, sizes and colors
- 102. Static layout
- 103. Need to manually create a different NIB file for each language
- 104. Creating GUIs without code On GNUstep , there is Gorm Works on GNUstep
- 105. Very similar to Interface Builder
- 106. Uses its own files (“Gorm” files)
- 107. Same pros/cons as Interface
- 108. Builder
- 109. Can import NIBs from Interface Builder (they might need manual adjustment after importing)
- 110. Creating GUIs without code On GNUstep , there is also Renaissance https://www.gnustep.it/Renaissance Works everywhere
- 111. GNU LGPL framework
- 112. Open XML file format
- 113. Not that complete
- 114. Lacking a GUI builder
- 115. Editable, portable text files
- 116. Autolayout using boxes and grids
- 117. Can load up translations at runtime: a single file can support all
- 118. languages <gsmarkup> <objects> <window title="This is a test window"> <button title="Print Hello!" action="printHello:" /> </window> </objects> </gsmarkup>
- 119. Creating GUIs without code Not Portable Portable GUI IDE Text files <gsmarkup> <objects> <window title="This is a test window"> <button title="Print Hello!" action="printHello:" /> </window> </objects> </gsmarkup> Interface Builder Gorm Renaissance Renaissance GUI Builder (TODO)
- 120. The future of free, cross-platform Objective-C Free, cross-platform Objective-C needs your help! Try out the GNUstep frameworks and tools
- 121. Give constructive feedback, suggest improvements, provide patches
- 123. Write applications
- 124. Port existing applications back and forth between GNUstep and Apple Cocoa
- 125. Help improving GNUstep ports to Windows and
- 126. other platforms