/*=========================================================================

  Program:   Visualization Toolkit
  Module:    vtkCocoaRenderWindowInteractor.mm

  Copyright (c) Ken Martin, Will Schroeder, Bill Lorensen
  All rights reserved.
  See Copyright.txt or http://www.kitware.com/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notice for more information.

=========================================================================*/
#import "vtkCocoaRenderWindowInteractor.h"
#import "vtkCocoaRenderWindow.h"
#import "vtkCommand.h"
#import "vtkObjectFactory.h"

#import <Cocoa/Cocoa.h>
#import <OpenGL/gl.h>

//----------------------------------------------------------------------------
vtkCxxRevisionMacro(vtkCocoaRenderWindowInteractor, "1.26");
vtkStandardNewMacro(vtkCocoaRenderWindowInteractor);

//----------------------------------------------------------------------------
void (*vtkCocoaRenderWindowInteractor::ClassExitMethod)(void *) = (void (*)(void *))NULL;
void *vtkCocoaRenderWindowInteractor::ClassExitMethodArg = (void *)NULL;
void (*vtkCocoaRenderWindowInteractor::ClassExitMethodArgDelete)(void *) = (void (*)(void *))NULL;

//----------------------------------------------------------------------------
// This is a private class and an implementation detail, do not use it.
//----------------------------------------------------------------------------
// As vtk is both crossplatform and a library, we don't know if it is being
// used in a 'regular Cocoa application' or as a 'pure vtk application'.
// By the former I mean a regular Cocoa application that happens to have
// a vtkCocoaGLView, by the latter I mean an application that only uses
// vtk APIs (which happen to use Cocoa as an implementation detail).
// Specifically, we can't know if NSApplicationMain() was ever called
// (which is usually done in main()), nor whether the NSApplication exists.
//
// Any code that uses Cocoa needs to be sure that NSAutoreleasePools are
// correctly setup.  Specifically, an NSAutoreleasePool needs to exist before
// any Cocoa objects are autoreleased, which may happen as a side effect of
// pretty much any Cocoa use.  Once we start the event loop by calling 
// either NSApplicationMain() or [NSApp run] then a new pool will be created
// for every event.  In a 'regular Cocoa application' NSApplicationMain() is
// called at the start of main() and so we know a pool will be in place before
// any vtk code is used.  But in a 'pure vtk application' the event loop does
// not start until [NSApp run] is called by this class's Start() method. The
// problem thus is that other vtk code may be called before Start() and that
// code may call Cocoa and thus autorelease objects with no autorelease pool
// in place.  The (ugly) solution is to create a 'pool of last resort' so
// that we know a pool is always in place.
// See: <http://lists.apple.com/archives/cocoa-dev/2006/Sep/msg00222.html>
//
// With garbage collection (GC), autorelease pools are a thing of the past,
// and this hack is not needed.  However, Obj-C code can be compiled in
// 1 of 3 memory management modes: GC unsupported (classic retain/release),
// GC supported, or GC required.  Library code like VTK should work with all 3.
// Until VTK can require 'GC required' this hack is still needed.
class vtkEarlyCocoaSetup
  {
    public:
    vtkEarlyCocoaSetup()
    {
      this->CreatePoolOfLastResort();
    }
    
    virtual ~vtkEarlyCocoaSetup()
    {
      this->DestroyPoolOfLastResort();
    }
    
    protected:
    void DestroyPoolOfLastResort()
    {
    // See Apple docs for drain vs release.  Alas, to support 10.3, we need this #if.
#if MAC_OS_X_VERSION_MIN_REQUIRED >= 1040
      [Pool drain];
#else
      [Pool release];
#endif
      Pool = nil;
    }
    
    void CreatePoolOfLastResort()
    {
      Pool = [[NSAutoreleasePool alloc] init];
    }
    
    private:
    NSAutoreleasePool     *Pool;
  };

// We create a global/static instance of this class to ensure that we have an
// autorelease pool before main() starts (the C++ constructor for a global
// object runs before main).  Note: I am unable to find a place to delete this
// object safely.
static vtkEarlyCocoaSetup * gEarlyCocoaSetup = new vtkEarlyCocoaSetup();

//----------------------------------------------------------------------------
// This is a private class and an implementation detail, do not use it.
//----------------------------------------------------------------------------
@interface vtkCocoaTimer : NSObject
{
  NSTimer *timer;
  vtkCocoaRenderWindowInteractor *interactor;
  int timerId;
}

- (id)initWithInteractor:(vtkCocoaRenderWindowInteractor *)myInteractor timerId:(int)myTimerId;
- (void)startTimerWithInterval:(NSTimeInterval)interval repeating:(BOOL)repeating;
- (void)stopTimer;
- (void)timerFired:(NSTimer *)myTimer;

@end

//----------------------------------------------------------------------------
@implementation vtkCocoaTimer

//----------------------------------------------------------------------------
- (id)initWithInteractor:(vtkCocoaRenderWindowInteractor *)myInteractor timerId:(int)myTimerId
{
  self = [super init]; 
  if (self)
    {
    interactor = myInteractor;
    timerId = myTimerId;
    }
  return self;
}

//----------------------------------------------------------------------------
- (void)timerFired:(NSTimer *)myTimer
{
  (void)myTimer;
  interactor->InvokeEvent(vtkCommand::TimerEvent, &timerId);
}

//----------------------------------------------------------------------------
- (void)startTimerWithInterval:(NSTimeInterval)interval repeating:(BOOL)repeating
{
  timer = [[NSTimer timerWithTimeInterval:interval
    target:self
    selector:@selector(timerFired:)
    userInfo:nil
    repeats:repeating] retain];
  [[NSRunLoop currentRunLoop] addTimer:timer forMode:NSDefaultRunLoopMode];
  [[NSRunLoop currentRunLoop] addTimer:timer forMode:NSEventTrackingRunLoopMode];
}

//----------------------------------------------------------------------------
- (void)stopTimer
{
  [timer invalidate];
  [timer release];
  timer = nil;
}

@end

// This is a private class and an implementation detail, do not use it.
// It manages the application run loop of a "pure vtk application",
// as opposed to a regular Mac app that happens to use VTK.
//----------------------------------------------------------------------------
@interface vtkCocoaServer : NSObject
{
  vtkCocoaRenderWindow* renWin;
}

+ (id)cocoaServerWithRenderWindow:(vtkCocoaRenderWindow *)inRenderWindow;

- (void)start;
- (void)stop;

@end

//----------------------------------------------------------------------------
@implementation vtkCocoaServer

//----------------------------------------------------------------------------
- (id)initWithRenderWindow:(vtkCocoaRenderWindow *)inRenderWindow
{
  self = [super init];
  if (self)
    {
    renWin = inRenderWindow;
    }
  return self;
}

//----------------------------------------------------------------------------
+ (id)cocoaServerWithRenderWindow:(vtkCocoaRenderWindow *)inRenderWindow
{
  vtkCocoaServer *server = [[[vtkCocoaServer alloc] 
                            initWithRenderWindow:inRenderWindow]
                            autorelease];
  return server;
}

//----------------------------------------------------------------------------
- (void)start
{
  // Retrieve the NSWindow.
  NSWindow *win = nil;
  if (renWin != NULL)
    {
    win = reinterpret_cast<NSWindow *>(renWin->GetWindowId());
  
  // We don't want to be informed of every window closing, so check for nil.
    if (win != nil)
    {
      // Register for the windowWillClose notification in order to stop
      // the run loop if the window closes.
      NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];
      [nc addObserver:self selector:@selector(windowWillClose:) 
                               name:@"NSWindowWillCloseNotification" 
                             object:win];
    }
    }

  // Now that we are about to begin the standard Cocoa event loop, we can get
  // rid of the 'pool of last resort' because [NSApp run] will create a new
  // pool for every event
  #ifndef __OBJC_GC__
  delete gEarlyCocoaSetup;
  gEarlyCocoaSetup = 0;
  #endif

  // Start the NSApplication's run loop
  [NSApp run];
}

//----------------------------------------------------------------------------
- (void)stop
{
  // Retrieve the NSWindow.
  NSWindow  *win = nil;
  if (renWin != NULL)
    {
    win = reinterpret_cast<NSWindow *>(renWin->GetWindowId());
    }
  
  // Close the window, removing it from the screen and releasing it
  [win close];
}

//----------------------------------------------------------------------------
- (void)windowWillClose:(NSNotification*)aNotification
{
  (void)aNotification;
  
  NSNotificationCenter *nc = [NSNotificationCenter defaultCenter];
  [nc removeObserver:self];
  
  if (renWin)
    {
    int windowCreated = renWin->GetWindowCreated();
    if (windowCreated)
      {
      // Stop the current run loop. Do not terminate as it will not return to
      // main. However, the stop message puts the run loop asleep. Let's send
      // some event to wake it up so it can get out of the loop.
      [NSApp stop:NSApp];

      NSEvent *event = [NSEvent otherEventWithType:NSApplicationDefined       
                                            location:NSMakePoint(0.0,0.0)
                                       modifierFlags:0
                                           timestamp:0
                                        windowNumber:-1
                                             context:nil
                                             subtype:0
                                               data1:0
                                               data2:0];
      [NSApp postEvent:event atStart:YES];
      
      // The NSWindow is closing, so prevent anyone from accidently using it
      renWin->SetWindowId(NULL);
      }
    }
} 

@end

//----------------------------------------------------------------------------
vtkCocoaRenderWindowInteractor::vtkCocoaRenderWindowInteractor() 
{
  this->InstallMessageProc = 1;
  
  // First, create the cocoa objects manager. The dictionary is empty so
  // essentially all objects are initialized to NULL.
  NSMutableDictionary * cocoaManager = [NSMutableDictionary dictionary];

  // SetCocoaManager works like an Obj-C setter, so do like Obj-C and 
  // init the ivar to null first.
  this->CocoaManager = NULL;
  this->SetCocoaManager(reinterpret_cast<void *>(cocoaManager));
  
  this->SetTimerDictionary(reinterpret_cast<void *>([NSMutableDictionary dictionary]));
}

//----------------------------------------------------------------------------
vtkCocoaRenderWindowInteractor::~vtkCocoaRenderWindowInteractor() 
{
  this->Enabled = 0;
  this->SetTimerDictionary(NULL);
  this->SetCocoaServer(NULL);
  this->SetCocoaManager(NULL);
}

//----------------------------------------------------------------------------
void vtkCocoaRenderWindowInteractor::Start() 
{
  // Let the compositing handle the event loop if it wants to.
  if (this->HasObserver(vtkCommand::StartEvent) && !this->HandleEventLoop)
    {
    this->InvokeEvent(vtkCommand::StartEvent,NULL);
    return;
    }

  // No need to do anything if this is a 'mapped' interactor
  if (!this->Enabled || !this->InstallMessageProc)
    {
    return;
    }
   
  // Start server.
  vtkCocoaRenderWindow *renWin = vtkCocoaRenderWindow::SafeDownCast(this->GetRenderWindow());
  if (renWin != NULL)
    {
    vtkCocoaServer *server = [vtkCocoaServer cocoaServerWithRenderWindow:renWin];
    this->SetCocoaServer(reinterpret_cast<void *>(server));
    [server start];
    }
}

//----------------------------------------------------------------------------
// Begin processing keyboard strokes.
void vtkCocoaRenderWindowInteractor::Initialize()
{
  vtkCocoaRenderWindow *renWin;
  int *size;

  // make sure we have a RenderWindow and camera
  if ( !this->RenderWindow ) 
    {
    vtkErrorMacro(<<"No renderer defined!");
    return;
    }
  if (this->Initialized)
    {
    return;
    }
  this->Initialized = 1;
  // get the info we need from the RenderingWindow
  renWin = (vtkCocoaRenderWindow *)(this->RenderWindow);
  renWin->Start();
  size = renWin->GetSize();

  renWin->GetPosition(); // update values of this->Position[2]

  this->Enable();
  this->Size[0] = size[0];
  this->Size[1] = size[1];
}

//----------------------------------------------------------------------------
void vtkCocoaRenderWindowInteractor::Enable() 
{
  if (this->Enabled) 
    {
    return;
    }

  // Set the RenderWindow's interactor so that when the vtkCocoaGLView tries
  // to handle events from the OS it will either handle them or ignore them
  this->GetRenderWindow()->SetInteractor(this);

  this->Enabled = 1;
  this->Modified();
}

//----------------------------------------------------------------------------
void vtkCocoaRenderWindowInteractor::Disable() 
{
  if (!this->Enabled) 
    {
    return;
    }

  // Set the RenderWindow's interactor so that when the vtkCocoaGLView tries
  // to handle events from the OS it will either handle them or ignore them
  this->GetRenderWindow()->SetInteractor(NULL);

  this->Enabled = 0;
  this->Modified();
}

//----------------------------------------------------------------------------
void vtkCocoaRenderWindowInteractor::TerminateApp() 
{
  // Retrieve the cocoa render window.
  vtkCocoaRenderWindow *renWin = vtkCocoaRenderWindow::SafeDownCast(this->RenderWindow);
  if (renWin)
    {
    // Check if the NSWindow was created by VTK. If so, let's use the
    // vtkCocoaServer to stop the application since it started it.
    // This means that the interactor was started using the Start method.
    // The vtkCocoaServer is used to get out of that method without quiting
    // the application, allowing to access code after the Start() call, like
    // object deletion for example.
    int windowCreated = renWin->GetWindowCreated();
    if (windowCreated)
      {
      vtkCocoaServer *server = reinterpret_cast<vtkCocoaServer *>(this->GetCocoaServer());
      [server stop];
      }
    else
      {     
      // The NSWindow was not created by vtk itself, so let's terminate the 
      // application as requested.
      [NSApp terminate:NSApp];
      }
    }
   
   // Release vtkCocoaServer if created by the start method.
   this->SetCocoaServer(NULL);
}

//----------------------------------------------------------------------------
int vtkCocoaRenderWindowInteractor::InternalCreateTimer(int timerId,
  int timerType, unsigned long duration)
{
  BOOL repeating = NO;

  if (RepeatingTimer == timerType)
    {
    repeating = YES;
    }

  // Create a vtkCocoaTimer and add it to a dictionary using the timerId
  // as key, this will let us find the vtkCocoaTimer later by timerId
  vtkCocoaTimer *cocoaTimer = [[vtkCocoaTimer alloc] initWithInteractor:this
    timerId:timerId];  
  NSString *timerIdAsStr = [NSString stringWithFormat:@"%i", timerId];
  NSMutableDictionary *timerDict = (NSMutableDictionary*)(this->GetTimerDictionary());
  [timerDict setObject:cocoaTimer forKey:timerIdAsStr];
  [cocoaTimer startTimerWithInterval:((NSTimeInterval)duration/1000.0)
    repeating:repeating];

  // In this implementation, timerId and platformTimerId are the same
  int platformTimerId = timerId;
  
  return platformTimerId;
}

//----------------------------------------------------------------------------
int vtkCocoaRenderWindowInteractor::InternalDestroyTimer(int platformTimerId)
{
  // In this implementation, timerId and platformTimerId are the same;
  // but calling this anyway is more correct
  int timerId = this->GetVTKTimerId(platformTimerId);

  NSString *timerIdAsStr = [NSString stringWithFormat:@"%i", timerId];
  NSMutableDictionary *timerDict = (NSMutableDictionary*)(this->GetTimerDictionary());
  vtkCocoaTimer* cocoaTimer = [timerDict objectForKey:timerIdAsStr];
  [timerDict removeObjectForKey:timerIdAsStr];

  if (nil != cocoaTimer)
    {
    [cocoaTimer stopTimer];
    [cocoaTimer release];
    return 1; // success
    }
  else
    {
    return 0; // fail
    }
}

//----------------------------------------------------------------------------
// Specify the default function to be called when an interactor needs to exit.
// This callback is overridden by an instance ExitMethod that is defined.
void vtkCocoaRenderWindowInteractor::SetClassExitMethod(void (*f)(void *),void *arg)
{
  if ( f != vtkCocoaRenderWindowInteractor::ClassExitMethod
  || arg != vtkCocoaRenderWindowInteractor::ClassExitMethodArg)
    {
    // delete the current arg if there is a delete method
    if ((vtkCocoaRenderWindowInteractor::ClassExitMethodArg)
     && (vtkCocoaRenderWindowInteractor::ClassExitMethodArgDelete))
      {
      (*vtkCocoaRenderWindowInteractor::ClassExitMethodArgDelete)
        (vtkCocoaRenderWindowInteractor::ClassExitMethodArg);
      }
    vtkCocoaRenderWindowInteractor::ClassExitMethod = f;
    vtkCocoaRenderWindowInteractor::ClassExitMethodArg = arg;

    // no call to this->Modified() since this is a class member function
    }
}

//----------------------------------------------------------------------------
// Set the arg delete method.  This is used to free user memory.
void vtkCocoaRenderWindowInteractor::SetClassExitMethodArgDelete(void (*f)(void *))
{
  if (f != vtkCocoaRenderWindowInteractor::ClassExitMethodArgDelete)
    {
    vtkCocoaRenderWindowInteractor::ClassExitMethodArgDelete = f;

    // no call to this->Modified() since this is a class member function
    }
}

//----------------------------------------------------------------------------
void vtkCocoaRenderWindowInteractor::PrintSelf(ostream& os, vtkIndent indent)
{
  this->Superclass::PrintSelf(os,indent);
  os << indent << "InstallMessageProc: " << this->InstallMessageProc << endl;
}

//----------------------------------------------------------------------------
void vtkCocoaRenderWindowInteractor::ExitCallback()
{
  if (this->HasObserver(vtkCommand::ExitEvent)) 
    {
    this->InvokeEvent(vtkCommand::ExitEvent,NULL);
    }
  else if (this->ClassExitMethod)
    {
    (*this->ClassExitMethod)(this->ClassExitMethodArg);
    }
  this->TerminateApp();
}

//----------------------------------------------------------------------------
void vtkCocoaRenderWindowInteractor::SetTimerDictionary(void *dictionary)
{
  if (dictionary != NULL)
    {
    NSMutableDictionary* manager = 
      reinterpret_cast<NSMutableDictionary *>(this->GetCocoaManager());
    [manager setObject:reinterpret_cast<id>(dictionary) 
                forKey:@"TimerDictionary"];
    }
  else
    {
    NSMutableDictionary* manager = 
      reinterpret_cast<NSMutableDictionary *>(this->GetCocoaManager());
    [manager removeObjectForKey:@"TimerDictionary"];
    }
}

//----------------------------------------------------------------------------
void *vtkCocoaRenderWindowInteractor::GetTimerDictionary()
{
  NSMutableDictionary* manager = 
    reinterpret_cast<NSMutableDictionary *>(this->GetCocoaManager());
  return reinterpret_cast<void *>([manager objectForKey:@"TimerDictionary"]);
}

//----------------------------------------------------------------------------
void vtkCocoaRenderWindowInteractor::SetCocoaServer(void *server)
{
  if (server != NULL)
    {
    NSMutableDictionary* manager = 
      reinterpret_cast<NSMutableDictionary *>(this->GetCocoaManager());
    [manager setObject:reinterpret_cast<vtkCocoaServer *>(server) 
                forKey:@"CocoaServer"];
    }
  else
    {
    NSMutableDictionary* manager = 
      reinterpret_cast<NSMutableDictionary *>(this->GetCocoaManager());
    [manager removeObjectForKey:@"CocoaServer"];
    }
}
  
//----------------------------------------------------------------------------
void *vtkCocoaRenderWindowInteractor::GetCocoaServer()
{
  NSMutableDictionary* manager = 
    reinterpret_cast<NSMutableDictionary *>(this->GetCocoaManager());
  return reinterpret_cast<void *>([manager objectForKey:@"CocoaServer"]);
}

//----------------------------------------------------------------------------
void vtkCocoaRenderWindowInteractor::SetCocoaManager(void *manager)
{
  NSMutableDictionary* currentCocoaManager = 
    reinterpret_cast<NSMutableDictionary *>(this->CocoaManager);
  NSMutableDictionary* newCocoaManager = 
    reinterpret_cast<NSMutableDictionary *>(manager);

  if (currentCocoaManager != newCocoaManager)
    {
    // Why not use Cocoa's retain and release?  Without garbage collection
    // (GC), the two are equivalent anyway because of 'toll free bridging',
    // so no problem there.  With GC, retain and release do nothing, but
    // CFRetain and CFRelease still manipulate the internal reference count.
    // We need that, since we are not using strong references (we don't want
    // it collected out from under us!).
    if (currentCocoaManager)
      {
      CFRelease(currentCocoaManager);
      }
    if (newCocoaManager)
      {
      this->CocoaManager = const_cast<void*>(CFRetain (newCocoaManager));
      }
    else
      {
      this->CocoaManager = NULL;
      }
    }
}
  
//----------------------------------------------------------------------------
void *vtkCocoaRenderWindowInteractor::GetCocoaManager()
{
  return this->CocoaManager;
}
