[fpc-devel] Creating a Cocoa Application

[Felipe Monteiro de Carvalho]

A compilable version. I updated it to include in itself very limited
appkit bindings so that one can run this example even without my
partial cocoa bindings. It requires the objc headers, however. In fact
I just made this the main objc headers example:

{
 cocoamsgbox.pas

 This example shows how to use the objective-c runtime headers to call
 initialization and finalization code for an objective-c class (in this case
 NSAutoreleasePool), and also shows a message box using minimal AppKit
 bindings to demonstrate that this can be used to build Cocoa applications.

 Compilation of this example requires the following options:
 -k-framework -kcocoa -k-lobjc

 This example project is released under public domain

 AUTHORS: Felipe Monteiro de Carvalho
}
program cocoamsgbox;

{$mode objfpc}{$H+}

uses
  objc, ctypes, FPCMacOSAll;

{ Very limited appkit bindings, just to run this example independently
  of the Cocoa bindings }

{ From AppKit/NSApplication.inc }
function NSApplicationLoad(): CBOOL; cdecl; external;

{ from AppKit/NSPanel.inc }
function NSRunAlertPanel(title, msg, defaultButton, alternateButton,
otherButton: CFStringRef; others: array of const): cint; cdecl;
external;

const
  Str_NSAutoreleasePool = 'NSAutoreleasePool';
  Str_alloc = 'alloc';
  Str_init = 'init';
  Str_release = 'release';
  Str_Panel_Title = 'This is the title';
  Str_Panel_Message = 'This is the message';
var
  { classes }
  NSAutoreleasePoolId: objc.id;
  { objects }
  allocbuf, pool: objc.id;
  { strings }
  CFTitle, CFMessage: CFStringRef;
begin
  {  NSAutoreleasePool* pool = [[NSAutoreleasePool alloc] init]; }
  NSAutoreleasePoolId := objc_getClass(PChar(Str_NSAutoreleasePool));
  allocbuf := objc_msgSend(NSAutoreleasePoolId,
sel_registerName(PChar(Str_alloc)), []);
  pool := objc_msgSend(allocbuf, sel_registerName(PChar(Str_init)), []);

  NSApplicationLoad();

  CFTitle := CFStringCreateWithCString(nil, PChar(Str_Panel_Title),
kCFStringEncodingUTF8);
  CFMessage := CFStringCreateWithCString(nil,
PChar(Str_Panel_Message), kCFStringEncodingUTF8);

  { uses a default "OK" button and no alternate buttons }
  NSRunAlertPanel(CFTitle, CFMessage, nil, nil, nil, []);

  CFRelease(CFTitle);
  CFRelease(CFMessage);

  {  [pool release]; }
  objc_msgSend(pool, sel_registerName(PChar(Str_release)), []);
end.