Demonstration Program CarbonScrap

// *******************************************************************************************
// CarbonScrap.c                                                            CARBON EVENT MODEL
// *******************************************************************************************
// 
// This program utilises Carbon Scrap Manager functions to allow the user to:
//
// o  Cut, copy, clear, and paste text and pictures from and to two document windows opened by
//    the program.
//
// o  Paste text and pictures cut or copied from another application to the two document 
//    windows.
//
// o  Open and close a Clipboard window, in which the current contents of the scrap are
//    displayed.
//
// The program's preferred scrap flavour type is 'TEXT'.  Thus, if the scrap contains data in
// both the 'TEXT' and 'PICT' flavour types, only the 'TEXT' flavour will be used for pastes
// to the document windows and display in the Clipboard window.
//
// In order to keep that part of the source code that is not related to the Carbon Scrap 
// Manager to a minimum, the windows do not display insertion points, nor can the pictures be
// dragged within the windows.  The text and pictures are not inserted into a document as 
// such.  Rather, when the Paste item in the Edit menu is chosen:
//
// o  The text or picture on the Clipboard is simply drawn in the centre of the active window.
//
// o  A handle to the text or picture is assigned to fields in a document structure associated
//    with the window.  (The demonstration program MonoTextEdit (Chapter 21) shows how to cut,
//    copy, and paste text from and to a TextEdit structure using the scrap.) 
//
// For the same reason, highlighting the selected text or picture in a window is simplified by
// simply inverting the image.
//
// The program utilises the following resources:
//
// o  A 'plst' resource.
//
// o  An 'MBAR' resource, and 'MENU' resources for Apple, File, and Edit menus (preload, 
//    non-purgeable).  
//
// o  A 'TEXT' resource (non-purgeable) containing text displayed in the left window at 
//    program  start. 
//
// o  A 'PICT' resource (non-purgeable) containing a picture displayed in the right window at
//    program start.
//
// o  A 'STR#' resource (purgeable) containing strings to be displayed in the error Alert.
//
// o  A 'SIZE' resource with the acceptSuspendResumeEvents, canBackground, 
//    doesActivateOnFGSwitch, and isHighLevelEventAware flags set.
//
// *******************************************************************************************

// .................................................................................. includes

#include <Carbon.h>

// ................................................................................... defines

#define rMenubar          128
#define mAppleApplication 128
#define  iAbout           1
#define mFile             129
#define  iClose           4
#define  iQuit            12
#define mEdit             130
#define  iCut             3
#define  iCopy            4
#define  iPaste           5
#define  iClear           6
#define  iClipboard       8
#define rText             128
#define rPicture          128
#define rErrorStrings     128
#define  eFailMenu        1
#define  eFailWindow      2
#define  eFailDocStruc    3
#define  eFailMemory      4
#define  eClearScrap      5
#define  ePutScrapFlavor  6
#define  eGetScrapSize    7
#define  eGetScrapData    8
#define kDocumentType     1
#define kClipboardType    2
#define MAX_UINT32        0xFFFFFFFF

// .................................................................................. typedefs

typedef struct
{
  PicHandle pictureHdl;
  Handle    textHdl;
  Boolean   selectFlag;
  SInt16    windowType;
} docStructure, **docStructureHandle;

// .......................................................................... global variables

Boolean   gRunningOnX         = false;
WindowRef gClipboardWindowRef = NULL;
Boolean   gClipboardShowing   = false;

// ....................................................................... function prototypes

void            main                   (void);
void            doPreliminaries        (void);
OSStatus        appEventHandler        (EventHandlerCallRef,EventRef,void *);
OSStatus        docWindowEventHandler  (EventHandlerCallRef,EventRef,void *);
OSStatus        clipWindowEventHandler (EventHandlerCallRef,EventRef,void *);
void            doAdjustMenus          (void);
void            doMenuChoice           (MenuID,MenuItemIndex);
void            doErrorAlert           (SInt16);
void            doOpenDocumentWindows  (void);
EventHandlerUPP doGetHandlerUPP        (void);
void            doCloseWindow          (void);
void            doInContent            (Point);
void            doCutCopyCommand       (Boolean);
void            doPasteCommand         (void);
void            doClearCommand         (void);
void            doClipboardCommand     (void);
void            doDrawClipboardWindow  (void);
void            doDrawDocumentWindow   (WindowRef);
Rect            doSetDestRect          (Rect *,WindowRef);

// ************************************************************************************** main

void  main(void)
{
  MenuBarHandle menubarHdl;
  SInt32        response;
  MenuRef       menuRef;
  EventTypeSpec applicationEvents[] = { { kEventClassApplication, kEventAppActivated    },
                                        { kEventClassApplication, kEventAppDeactivated  },
                                        { kEventClassCommand,     kEventProcessCommand  },
                                        { kEventClassMenu,        kEventMenuEnableItems } };

  // ........................................................................ do preliminaries

  doPreliminaries();

  // ............................................................... set up menu bar and menus

  menubarHdl = GetNewMBar(rMenubar);
  if(menubarHdl == NULL)
    doErrorAlert(eFailMenu);
  SetMenuBar(menubarHdl);
  DrawMenuBar();

  Gestalt(gestaltMenuMgrAttr,&response);
  if(response & gestaltMenuMgrAquaLayoutMask)
  {
    menuRef = GetMenuRef(mFile);
    if(menuRef != NULL)
    {
      DeleteMenuItem(menuRef,iQuit);
      DeleteMenuItem(menuRef,iQuit - 1);
      DisableMenuItem(menuRef,0);
    }

    gRunningOnX = true;
  }
  else
  {
    menuRef = GetMenuRef(mFile);
    if(menuRef != NULL)
      SetMenuItemCommandID(menuRef,iQuit,kHICommandQuit);
  }

  // ................................................................... open document windows

  doOpenDocumentWindows();

  // ....................................................... install application event handler

  InstallApplicationEventHandler(NewEventHandlerUPP((EventHandlerProcPtr) appEventHandler),
                                 GetEventTypeCount(applicationEvents),applicationEvents,
                                 0,NULL);

  // .............................................................. run application event loop

  RunApplicationEventLoop();
}

// *************************************************************************** doPreliminaries

void  doPreliminaries(void)
{
  MoreMasterPointers(96);
  InitCursor();
}

// *************************************************************************** appEventHandler

OSStatus  appEventHandler(EventHandlerCallRef eventHandlerCallRef,EventRef eventRef,
                          void * userData)
{
  OSStatus      result = eventNotHandledErr;
  UInt32        eventClass;
  UInt32        eventKind;
  HICommand     hiCommand;
  MenuID        menuID;
  MenuItemIndex menuItem;

  eventClass = GetEventClass(eventRef);
  eventKind  = GetEventKind(eventRef);

  switch(eventClass)
  {
    case kEventClassApplication:
      if(eventKind == kEventAppActivated)
      {
        SetThemeCursor(kThemeArrowCursor);
        if(gClipboardWindowRef && gClipboardShowing)
          ShowWindow(gClipboardWindowRef);
      }
      else if(eventKind == kEventAppDeactivated)
      {
        if(gClipboardWindowRef && gClipboardShowing)
          ShowHide(gClipboardWindowRef,false);
      }
    break;

    case kEventClassCommand:
      if(eventKind == kEventProcessCommand)
      {
        GetEventParameter(eventRef,kEventParamDirectObject,typeHICommand,NULL,
                          sizeof(HICommand),NULL,&hiCommand);
        menuID = GetMenuID(hiCommand.menu.menuRef);
        menuItem = hiCommand.menu.menuItemIndex;
        if((hiCommand.commandID != kHICommandQuit) && 
           (menuID >= mAppleApplication && menuID <= mEdit))
        {
          doMenuChoice(menuID,menuItem);
          result = noErr;
        }
      }
      break;
      
    case kEventClassMenu:
      if(eventKind == kEventMenuEnableItems)
        doAdjustMenus();
      result = noErr;
      break;
  }

  return result;
}

// ********************************************************************* docWindowEventHandler

OSStatus  docWindowEventHandler(EventHandlerCallRef eventHandlerCallRef,EventRef eventRef,
                                void * userData)
{
  OSStatus           result = eventNotHandledErr;
  UInt32             eventClass;
  UInt32             eventKind;
  WindowRef          windowRef;
  docStructureHandle docStrucHdl;
  Point              mouseLocation;
  
  eventClass = GetEventClass(eventRef);
  eventKind  = GetEventKind(eventRef);

  switch(eventClass)
  {
    case kEventClassWindow:
      GetEventParameter(eventRef,kEventParamDirectObject,typeWindowRef,NULL,sizeof(windowRef),
                    NULL,&windowRef);
      switch(eventKind)
      {
        case kEventWindowDrawContent:
          docStrucHdl = (docStructureHandle) GetWRefCon(windowRef);
          if((*docStrucHdl)->pictureHdl != NULL || (*docStrucHdl)->textHdl != NULL)
            doDrawDocumentWindow(windowRef);
          result = noErr;
          break;
        
        case kEventWindowClickContentRgn:
          GetEventParameter(eventRef,kEventParamMouseLocation,typeQDPoint,NULL,
                            sizeof(mouseLocation),NULL,&mouseLocation);
          SetPortWindowPort(windowRef);
          GlobalToLocal(&mouseLocation);
          doInContent(mouseLocation);
          result = noErr;
          break;
      }
      break;
  }

  return result;
}

// ******************************************************************** clipWindowEventHandler

OSStatus  clipWindowEventHandler(EventHandlerCallRef eventHandlerCallRef,EventRef eventRef,
                                 void * userData)
{
  OSStatus result = eventNotHandledErr;
  UInt32   eventClass;
  UInt32   eventKind;
  MenuRef  editMenuRef;
  
  eventClass = GetEventClass(eventRef);
  eventKind  = GetEventKind(eventRef);

  if(eventClass == kEventClassWindow)
  {
    switch(eventKind)
    {
      case kEventWindowActivated:
      case kEventWindowDeactivated:
      case kEventWindowDrawContent:
        doDrawClipboardWindow();
        result = noErr;
        break;

      case kEventWindowClose:
        DisposeWindow(gClipboardWindowRef);
        gClipboardWindowRef = NULL;
        gClipboardShowing = false;
        editMenuRef = GetMenuRef(mEdit);
        SetMenuItemText(editMenuRef,iClipboard,"\pShow Clipboard");
        break;
    }
  }    

  return result;
}

// ***************************************************************************** doAdjustMenus

void  doAdjustMenus(void)
{
  MenuRef            fileMenuRef, editMenuRef;
  docStructureHandle docStrucHdl;
  ScrapRef           scrapRef;
  OSStatus           osError;
  ScrapFlavorFlags   scrapFlavorFlags;
  Boolean            scrapHasText = false, scrapHasPicture = false;

  fileMenuRef = GetMenuRef(mFile);
  editMenuRef = GetMenuRef(mEdit);

  docStrucHdl = (docStructureHandle) GetWRefCon(FrontWindow());

  if((*docStrucHdl)->windowType == kClipboardType)
    EnableMenuItem(fileMenuRef,iClose);
  else
    DisableMenuItem(fileMenuRef,iClose);

  if(((*docStrucHdl)->pictureHdl || (*docStrucHdl)->textHdl) && ((*docStrucHdl)->selectFlag))
  {
    EnableMenuItem(editMenuRef,iCut);
    EnableMenuItem(editMenuRef,iCopy);
    EnableMenuItem(editMenuRef,iClear);
  }
  else
  {
    DisableMenuItem(editMenuRef,iCut);
    DisableMenuItem(editMenuRef,iCopy);
    DisableMenuItem(editMenuRef,iClear);
  }

  GetCurrentScrap(&scrapRef);

  osError = GetScrapFlavorFlags(scrapRef,kScrapFlavorTypeText,&scrapFlavorFlags);
  if(osError == noErr)
    scrapHasText = true;

  osError = GetScrapFlavorFlags(scrapRef,kScrapFlavorTypePicture,&scrapFlavorFlags);
  if(osError == noErr)
    scrapHasPicture = true;

  if((scrapHasText || scrapHasPicture) && ((*docStrucHdl)->windowType != kClipboardType))
    EnableMenuItem(editMenuRef,iPaste);
  else
    DisableMenuItem(editMenuRef,iPaste);

  DrawMenuBar();
}

// ****************************************************************************** doMenuChoice

void  doMenuChoice(MenuID menuID,MenuItemIndex menuItem)
{
  if(menuID == 0)
    return;

  switch(menuID)
  {
    case mAppleApplication:
      if(menuItem == iAbout)
        SysBeep(10);
      break;

    case mFile:
      if(menuItem == iClose)
        doCloseWindow();
      break;

    case mEdit:
      switch(menuItem)
      {
        case iCut:
          doCutCopyCommand(true);
          break;

        case iCopy:
          doCutCopyCommand(false);
          break;

        case iPaste:
          doPasteCommand();
          break;

        case iClear:
          doClearCommand();
          break;

        case iClipboard:
          doClipboardCommand();
          break;
      }
      break;    
  }
}

// ****************************************************************************** doErrorAlert

void  doErrorAlert(SInt16 errorCode)
{
  Str255  errorString;
  SInt16  itemHit;

  GetIndString(errorString,rErrorStrings,errorCode);
  StandardAlert(kAlertStopAlert,errorString,NULL,NULL,&itemHit);
  ExitToShell();
}

// ********************************************************************* doOpenDocumentWindows

void  doOpenDocumentWindows(void)
{
  SInt16             a;
  OSStatus           osError;
  WindowRef          windowRef;
  Rect               contentRect = { 43,7,223,297 }, theRect;
  Str255             title1      = "\pDocument A";
  Str255             title2      = "\pDocument B";
  docStructureHandle docStrucHdl;
  EventTypeSpec      windowEvents[] = { { kEventClassWindow,  kEventWindowDrawContent     },
                                        { kEventClassWindow,  kEventWindowClickContentRgn } };

  for(a=0;a<2;a++)
  {
    osError = CreateNewWindow(kDocumentWindowClass,kWindowStandardHandlerAttribute,
                              &contentRect,&windowRef);
    if(osError != noErr)
      doErrorAlert(eFailWindow);      

    if(a == 0)
    {
      SetWTitle(windowRef,"\pDocument A");
      OffsetRect(&contentRect,305,0);
    }
    else
      SetWTitle(windowRef,"\pDocument B");

    if(!(docStrucHdl = (docStructureHandle) NewHandle(sizeof(docStructure))))
      doErrorAlert(eFailDocStruc);
    SetWRefCon(windowRef,(SInt32) docStrucHdl);

    (*docStrucHdl)->pictureHdl = NULL;
    (*docStrucHdl)->textHdl    = NULL;
    (*docStrucHdl)->windowType = kDocumentType;
    (*docStrucHdl)->selectFlag = false;
  
    SetPortWindowPort(windowRef);

    if(gRunningOnX)
    {
      GetWindowPortBounds(windowRef,&theRect);
      InsetRect(&theRect,40,40);
      ClipRect(&theRect);
    }
    else
      UseThemeFont(kThemeSmallSystemFont,smSystemScript);
    
    if(a == 0)
      (*docStrucHdl)->textHdl = (Handle) GetResource('TEXT',rText);
    else
      (*docStrucHdl)->pictureHdl = GetPicture(rPicture);

    InstallWindowEventHandler(windowRef,doGetHandlerUPP(),GetEventTypeCount(windowEvents),
                              windowEvents,0,NULL);

    ShowWindow(windowRef);
  }
}

// *************************************************************************** doGetHandlerUPP

EventHandlerUPP  doGetHandlerUPP(void)
{
  static EventHandlerUPP  windowEventHandlerUPP;

  if(windowEventHandlerUPP == NULL)
    windowEventHandlerUPP = NewEventHandlerUPP((EventHandlerProcPtr) docWindowEventHandler);

  return windowEventHandlerUPP;
}

// ***************************************************************************** doCloseWindow

void  doCloseWindow(void)
{
  WindowRef          windowRef;
  docStructureHandle docStrucHdl;
  MenuRef            editMenuRef;

  windowRef = FrontWindow();
  docStrucHdl = (docStructureHandle) GetWRefCon(windowRef);

  if((*docStrucHdl)->windowType == kClipboardType)
  {
    DisposeWindow(windowRef);
    gClipboardWindowRef = NULL;
    gClipboardShowing = false;
    editMenuRef = GetMenuRef(mEdit);
    SetMenuItemText(editMenuRef,iClipboard,"\pShow Clipboard");
  }
}

// ******************************************************************************* doInContent

void  doInContent(Point mouseLocation)
{
  WindowRef          windowRef;
  docStructureHandle docStrucHdl;
  GrafPtr            oldPort;
  Rect               theRect;

  windowRef = FrontWindow();
  docStrucHdl = (docStructureHandle) GetWRefCon(windowRef);

  if((*docStrucHdl)->windowType == kClipboardType)
    return;

  GetPort(&oldPort);
  SetPortWindowPort(windowRef);

  if((*docStrucHdl)->textHdl != NULL || (*docStrucHdl)->pictureHdl != NULL)
  {
    if((*docStrucHdl)->textHdl != NULL)
    {
      GetWindowPortBounds(windowRef,&theRect);
      InsetRect(&theRect,40,40);
    }
    else if((*docStrucHdl)->pictureHdl != NULL) 
    {
      theRect = doSetDestRect(&(*(*docStrucHdl)->pictureHdl)->picFrame,windowRef);
    }

    if(PtInRect(mouseLocation,&theRect) && (*docStrucHdl)->selectFlag == false)
    {
      (*docStrucHdl)->selectFlag = true;
      InvertRect(&theRect);
    }
    else if(!PtInRect(mouseLocation,&theRect) && (*docStrucHdl)->selectFlag == true)
    {
      (*docStrucHdl)->selectFlag = false;
      InvertRect(&theRect);
    }
  }

  SetPort(oldPort);
}

// ************************************************************************** doCutCopyCommand

void  doCutCopyCommand(Boolean cutFlag)
{
  WindowRef          windowRef;
  docStructureHandle docStrucHdl;  
  OSStatus           osError;
  ScrapRef           scrapRef;
  Size               dataSize;
  GrafPtr            oldPort;
  Rect               portRect;

  windowRef = FrontWindow();
  docStrucHdl = (docStructureHandle) GetWRefCon(windowRef);

  if((*docStrucHdl)->selectFlag == false)
    return;

  osError = ClearCurrentScrap();
  if(osError == noErr)
  {
    GetCurrentScrap(&scrapRef);

    if((*docStrucHdl)->textHdl != NULL)  // ............................................'TEXT'
    {
      dataSize = GetHandleSize((Handle) (*docStrucHdl)->textHdl);
      HLock((*docStrucHdl)->textHdl);

      osError = PutScrapFlavor(scrapRef,kScrapFlavorTypeText,kScrapFlavorMaskNone,
                               dataSize,*((*docStrucHdl)->textHdl));
      if(osError != noErr)
        doErrorAlert(ePutScrapFlavor);
    }
    else if((*docStrucHdl)->pictureHdl != NULL)  // ................................... 'PICT'
    {
      dataSize = GetHandleSize((Handle) (*docStrucHdl)->pictureHdl);
      HLock((Handle) (*docStrucHdl)->pictureHdl);

      osError = PutScrapFlavor(scrapRef,kScrapFlavorTypePicture,kScrapFlavorMaskNone,
                                dataSize,*((Handle) (*docStrucHdl)->pictureHdl));
      if(osError != noErr)
        doErrorAlert(ePutScrapFlavor);
    }

    if((*docStrucHdl)->textHdl != NULL)
      HUnlock((*docStrucHdl)->textHdl);
    if((*docStrucHdl)->pictureHdl != NULL)
      HUnlock((Handle) (*docStrucHdl)->pictureHdl);
  }
  else
    doErrorAlert(eClearScrap);

  if(cutFlag)
  {
    GetPort(&oldPort);
    SetPortWindowPort(windowRef);

    if((*docStrucHdl)->pictureHdl != NULL)
    {
      DisposeHandle((Handle) (*docStrucHdl)->pictureHdl);
      (*docStrucHdl)->pictureHdl = NULL;
      (*docStrucHdl)->selectFlag = false;
    }
    if((*docStrucHdl)->textHdl != NULL)
    {
      DisposeHandle((*docStrucHdl)->textHdl);
      (*docStrucHdl)->textHdl = NULL;
      (*docStrucHdl)->selectFlag = false;
    }

    GetWindowPortBounds(windowRef,&portRect);
    EraseRect(&portRect);

    SetPort(oldPort);
  }

  if(gClipboardWindowRef != NULL)
    doDrawClipboardWindow();
}

// **************************************************************************** doPasteCommand

void  doPasteCommand(void)
{
  WindowRef          windowRef;
  docStructureHandle docStrucHdl;  
  GrafPtr            oldPort;
  ScrapRef           scrapRef;
  OSStatus           osError;
  ScrapFlavorFlags   flavorFlags;
  Size               sizeOfPictData = 0, sizeOfTextData = 0;
  Handle             newTextHdl, newPictHdl;
  CFStringRef        stringRef;
  Rect               destRect, portRect;  
  
  windowRef = FrontWindow();
  docStrucHdl = (docStructureHandle) GetWRefCon(windowRef);

  GetPort(&oldPort);
  SetPortWindowPort(windowRef);  

  GetCurrentScrap(&scrapRef);

  // .................................................................................. 'TEXT'

  osError = GetScrapFlavorFlags(scrapRef,kScrapFlavorTypeText,&flavorFlags);
  if(osError == noErr)
  {
    osError = GetScrapFlavorSize(scrapRef,kScrapFlavorTypeText,&sizeOfTextData);
    if(osError == noErr && sizeOfTextData > 0)
    {
      newTextHdl = NewHandle(sizeOfTextData);  
      osError = MemError();
      if(osError == memFullErr)
        doErrorAlert(eFailMemory);

      HLock(newTextHdl);

      osError = GetScrapFlavorData(scrapRef,kScrapFlavorTypeText,&sizeOfTextData,*newTextHdl);
      if(osError != noErr)
        doErrorAlert(eGetScrapData);
    
      // ................................................................. draw text in window

      GetWindowPortBounds(windowRef,&portRect);
      EraseRect(&portRect);
      InsetRect(&portRect,40,40);
      
      if(!gRunningOnX)
      {
        TETextBox(*newTextHdl,sizeOfTextData,&portRect,teFlushLeft);
      }
      else
      {
        stringRef =  CFStringCreateWithBytes(NULL,(UInt8 *) *newTextHdl,sizeOfTextData,
                                            smSystemScript,false);
        DrawThemeTextBox(stringRef,kThemeSmallSystemFont,kThemeStateActive,true,&portRect,
                         teFlushLeft,NULL);
        if(stringRef != NULL)                         
          CFRelease(stringRef);
      }

      HUnlock(newTextHdl);

      (*docStrucHdl)->selectFlag = false;

      // ............................ assign handle to new text to window's document structure

      if((*docStrucHdl)->textHdl != NULL)
        DisposeHandle((*docStrucHdl)->textHdl);
      (*docStrucHdl)->textHdl = newTextHdl;

      if((*docStrucHdl)->pictureHdl != NULL)
        DisposeHandle((Handle) (*docStrucHdl)->pictureHdl);
      (*docStrucHdl)->pictureHdl = NULL;
    }
    else
      doErrorAlert(eGetScrapSize);
  }

  // ................................................................................. ' PICT'

  else 
  {
    (osError = GetScrapFlavorFlags(scrapRef,kScrapFlavorTypePicture,&flavorFlags));
    if(osError == noErr)
    {
      osError = GetScrapFlavorSize(scrapRef,kScrapFlavorTypePicture,&sizeOfPictData);
      if(osError == noErr && sizeOfPictData > 0)
      {
        newPictHdl = NewHandle(sizeOfPictData);  
        osError = MemError();
        if(osError == memFullErr)
          doErrorAlert(eFailMemory);

        HLock(newPictHdl);

        osError = GetScrapFlavorData(scrapRef,kScrapFlavorTypePicture,&sizeOfPictData,
                                   *newPictHdl);
        if(osError != noErr)
          doErrorAlert(eGetScrapData);

        // ............................................................ draw picture in window

        GetWindowPortBounds(windowRef,&portRect);
        EraseRect(&portRect);
        (*docStrucHdl)->selectFlag = false;
        destRect = doSetDestRect(&(*(PicHandle) newPictHdl)->picFrame,windowRef);
        DrawPicture((PicHandle) newPictHdl,&destRect);

        HUnlock(newPictHdl);

        (*docStrucHdl)->selectFlag = false;

        // ....................... assign handle to new picture to window's document structure

        if((*docStrucHdl)->pictureHdl != NULL)
          DisposeHandle((Handle) (*docStrucHdl)->pictureHdl);
        (*docStrucHdl)->pictureHdl = (PicHandle) newPictHdl;

  
        if((*docStrucHdl)->textHdl != NULL)
          DisposeHandle((Handle) (*docStrucHdl)->textHdl);
        (*docStrucHdl)->textHdl = NULL;
      }
      else
        doErrorAlert(eGetScrapSize);
    }
  }

  SetPort(oldPort);
}

// **************************************************************************** doClearCommand

void  doClearCommand(void)
{
  WindowRef          windowRef;
  docStructureHandle docStrucHdl;  
  GrafPtr            oldPort;
  Rect               portRect;

  windowRef = FrontWindow();
  docStrucHdl = (docStructureHandle) GetWRefCon(windowRef);

  GetPort(&oldPort);
  SetPortWindowPort(windowRef);

  if((*docStrucHdl)->textHdl != NULL)
  {
    DisposeHandle((*docStrucHdl)->textHdl);
    (*docStrucHdl)->textHdl = NULL;
  }

  if((*docStrucHdl)->pictureHdl != NULL)
  {
    DisposeHandle((Handle) (*docStrucHdl)->pictureHdl);
    (*docStrucHdl)->pictureHdl = NULL;
  }
  
  (*docStrucHdl)->selectFlag = false;

  GetWindowPortBounds(windowRef,&portRect);
  EraseRect(&portRect);

  SetPort(oldPort);
}

// ************************************************************************ doClipboardCommand

void  doClipboardCommand(void)
{
  MenuRef            editMenuRef;
  OSStatus           osError;
  Rect               contentRect = { 254,7,384,603 };
  docStructureHandle docStrucHdl;  
  EventTypeSpec      windowEvents[] = { { kEventClassWindow, kEventWindowActivated   },
                                        { kEventClassWindow, kEventWindowDeactivated },
                                        { kEventClassWindow, kEventWindowDrawContent },
                                        { kEventClassWindow, kEventWindowClose       } };
  editMenuRef = GetMenuRef(mEdit);

  if(gClipboardWindowRef == NULL)
  {
    osError = CreateNewWindow(kDocumentWindowClass,kWindowStandardHandlerAttribute |
                              kWindowCloseBoxAttribute,&contentRect,&gClipboardWindowRef);
    if(osError != noErr)
      doErrorAlert(eFailWindow);      

    SetWTitle(gClipboardWindowRef,"\pClipboard");
    SetPortWindowPort(gClipboardWindowRef);  

    if(!(docStrucHdl = (docStructureHandle) NewHandle(sizeof(docStructure))))
      doErrorAlert(eFailDocStruc);

    SetWRefCon(gClipboardWindowRef,(SInt32) docStrucHdl);
    (*docStrucHdl)->windowType = kClipboardType;

    SetMenuItemText(editMenuRef,iClipboard,"\pHide Clipboard");

    InstallWindowEventHandler(gClipboardWindowRef,
                            NewEventHandlerUPP((EventHandlerProcPtr) clipWindowEventHandler),
                            GetEventTypeCount(windowEvents),windowEvents,0,NULL);

    ShowWindow(gClipboardWindowRef);
    gClipboardShowing = true;
  }
  else
  {
    if(gClipboardShowing)
    {
      HideWindow(gClipboardWindowRef);
      gClipboardShowing = false;
      SetMenuItemText(editMenuRef,iClipboard,"\pShow Clipboard");
    }
    else
    {
      ShowWindow(gClipboardWindowRef);
      gClipboardShowing = true;
      SetMenuItemText(editMenuRef,iClipboard,"\pHide Clipboard");        
    }
  }
}

// ********************************************************************* doDrawClipboardWindow

void  doDrawClipboardWindow(void)
{
  GrafPtr          oldPort;
  Rect             theRect, textBoxRect;
  ScrapRef         scrapRef;
  OSStatus         osError;
  ScrapFlavorFlags flavorFlags;
  CFStringRef      stringRef;
  Handle           tempHdl;
  Size             sizeOfPictData = 0, sizeOfTextData = 0;
  RGBColor         blackColour = { 0x0000, 0x0000, 0x0000 };
  
  GetPort(&oldPort);
  SetPortWindowPort(gClipboardWindowRef);  

  GetWindowPortBounds(gClipboardWindowRef,&theRect);
  EraseRect(&theRect);

  SetRect(&theRect,-1,-1,597,24);
  DrawThemeWindowHeader(&theRect,gClipboardWindowRef == FrontWindow());

  if(gClipboardWindowRef == FrontWindow())
    TextMode(srcOr);
  else
    TextMode(grayishTextOr);

  SetRect(&textBoxRect,10,5,120,20);
  DrawThemeTextBox(CFSTR("Clipboard Contents:"),kThemeSmallSystemFont,0,true,&textBoxRect,
                   teJustLeft,NULL);
  
  GetCurrentScrap(&scrapRef);

  // .................................................................................. 'TEXT'

  osError = GetScrapFlavorFlags(scrapRef,kScrapFlavorTypeText,&flavorFlags);
  if(osError == noErr)
  {
    osError = GetScrapFlavorSize(scrapRef,kScrapFlavorTypeText,&sizeOfTextData);
    if(osError == noErr && sizeOfTextData > 0)
    {
      SetRect(&textBoxRect,120,5,597,20);
      DrawThemeTextBox(CFSTR("Text"),kThemeSmallSystemFont,0,true,&textBoxRect,teJustLeft,
                       NULL);
 
      tempHdl = NewHandle(sizeOfTextData);  
      osError = MemError();
      if(osError == memFullErr)
        doErrorAlert(eFailMemory);

      HLock(tempHdl);

      osError = GetScrapFlavorData(scrapRef,kScrapFlavorTypeText,&sizeOfTextData,*tempHdl);
      if(osError != noErr)
        doErrorAlert(eGetScrapData);

      // ....................................................... draw text in clipboard window

      GetWindowPortBounds(gClipboardWindowRef,&theRect);
      theRect.top += 22;
      InsetRect(&theRect,2,2);

      if(sizeOfTextData >= 965)
        sizeOfTextData = 965;
      stringRef =  CFStringCreateWithBytes(NULL,(UInt8 *) *tempHdl,sizeOfTextData,
                                          CFStringGetSystemEncoding(),true);    
      DrawThemeTextBox(stringRef,kThemeSmallSystemFont,0,true,&theRect,teFlushLeft,NULL);
      if(stringRef != NULL)
        CFRelease(stringRef);

      HUnlock(tempHdl);
      DisposeHandle(tempHdl);
    }
    else
      doErrorAlert(eGetScrapSize);
  }

  // .................................................................................. 'PICT'

  else 
  {
    osError = GetScrapFlavorFlags(scrapRef,kScrapFlavorTypePicture,&flavorFlags);
    if(osError == noErr)
    {
      osError = GetScrapFlavorSize(scrapRef,kScrapFlavorTypePicture,&sizeOfPictData);
      if(osError == noErr && sizeOfPictData > 0)
      {
        SetRect(&textBoxRect,120,5,597,20);
        DrawThemeTextBox(CFSTR("Picture"),kThemeSmallSystemFont,0,true,&textBoxRect,
                         teJustLeft,NULL);

        tempHdl = NewHandle(sizeOfPictData);
        osError = MemError();
        if(osError == memFullErr)
          doErrorAlert(eFailMemory);

        HLock(tempHdl);

        osError = GetScrapFlavorData(scrapRef,kScrapFlavorTypePicture,&sizeOfPictData,
                                     *tempHdl);
        if(osError != noErr)
          doErrorAlert(eGetScrapData);

        // .................................................. draw picture in clipboard window

        theRect = (*(PicHandle) tempHdl)->picFrame;
        OffsetRect(&theRect,-((*(PicHandle) tempHdl)->picFrame.left - 2),
                            -((*(PicHandle) tempHdl)->picFrame.top - 26));
        DrawPicture((PicHandle) tempHdl,&theRect);

        HUnlock(tempHdl);
        DisposeHandle(tempHdl);
      }
      else
        doErrorAlert(eGetScrapSize);
    }
  }

  TextMode(srcOr);
  SetPort(oldPort);
}

// ********************************************************************** doDrawDocumentWindow

void  doDrawDocumentWindow(WindowRef windowRef)
{
  GrafPtr            oldPort;
  docStructureHandle docStrucHdl;
  Rect               destRect;
  CFStringRef        stringRef;

  GetPort(&oldPort);
  SetPortWindowPort(windowRef);

  docStrucHdl = (docStructureHandle) GetWRefCon(windowRef);

  if((*docStrucHdl)->textHdl != NULL)
  {
    GetWindowPortBounds(windowRef,&destRect);
    EraseRect(&destRect);
    InsetRect(&destRect,40,40);

    stringRef =  CFStringCreateWithBytes(NULL,(UInt8 *) *(*docStrucHdl)->textHdl,
                                        GetHandleSize((*docStrucHdl)->textHdl),
                                        smSystemScript,false);
    DrawThemeTextBox(stringRef,kThemeSmallSystemFont,0,true,&destRect,teFlushLeft,NULL);
    if(stringRef != NULL)
      CFRelease(stringRef);

    if((*docStrucHdl)->selectFlag)
      InvertRect(&destRect);
  }
  else if((*docStrucHdl)->pictureHdl != NULL)
  {
    destRect = doSetDestRect(&(*(*docStrucHdl)->pictureHdl)->picFrame,windowRef);
    DrawPicture((*docStrucHdl)->pictureHdl,&destRect);
    if((*docStrucHdl)->selectFlag)
      InvertRect(&destRect);
  }
 
  SetPort(oldPort);
}

// ***************************************************************************** doSetDestRect

Rect  doSetDestRect(Rect *picFrame,WindowRef windowRef)
{
  Rect   destRect, portRect;
  SInt16 diffX, diffY;

  destRect = *picFrame;
  GetWindowPortBounds(windowRef,&portRect);
  
  OffsetRect(&destRect,-(*picFrame).left,-(*picFrame).top);

  diffX = (portRect.right - portRect.left) - ((*picFrame).right - (*picFrame).left);
  diffY = (portRect.bottom - portRect.top) - ((*picFrame).bottom - (*picFrame).top);

  OffsetRect(&destRect,diffX / 2,diffY / 2);

  return destRect;
}

// *******************************************************************************************

Demonstration Program CarbonScrap Comments

When this program is run, the user should choose the Edit menu's Show Clipboard item to
open the Clipboard window.  The user should then cut, copy, clear and paste the supplied text
or picture from/to the two document windows opened by the program, noting the effect on the
scrap as displayed in the Clipboard window.  (To indicate selection, the text or picture
inverts when the user clicks on it with the mouse.  The text and picture can be deselected by
clicking outside their boundaries.)

The user should also copy text and pictures from another application's window, observing the
changes to the contents of the Clipboard window when the demonstration program is brought to
the front, and paste that text and those pictures to the document windows.  (On Mac OS 8/9, a
simple way to get a picture into the scrap is to use Command-Shift-Control-4 to copy an area of
the screen to the scrap.)

The program's preferred scrap flavour type is 'TEXT'.  Thus, if the scrap contains data in both
the 'TEXT' and 'PICT' flavour types, only the 'TEXT' flavour will be used for pastes to the
document windows and for display in the Clipboard window.  The user can prove this behaviour by
copying a picture object containing text in an application such as Adobe Illustrator, bringing
the demonstration program to the front, noting the contents of the Clipboard window, pasting to
one of the document windows, and noting what is pasted.

The user should note that, when the Clipboard window is open and showing, it will be hidden
when the program is sent to the background and shown again when the program is brought to the
foreground.

defines

kDocumentType and kClipboardType will enable the program to distinguish between the
"document" windows opened by the program and the Clipboard window.

typedefs

Document structures will be attached to the two document windows and the Clipboard window. 
docStructure is the associated data type.  The windowType field will be used to differentiate
between the document windows and the Clipboard window.

Global Variables

gClipBoardWindowRef will be assigned a reference to the Clipboard window when it is opened
by the user.  gClipBoardShowing will keep track of whether the Clipboard window is currently
hidden or showing.

appEventHandler

When the kEventAppActivated event type is received, if the Clipboard window has been
opened and was showing when the program was sent to the background, ShowWindow is called to
show the Clipboard window.  When the kEventAppActivated event type is received, if the
Clipboard window has been opened and is currently showing, ShowHide is called to hide the
Clipboard window.  ShowHide, rather than HideWindow is used in this instance to prevent
activation of the first document window in the list when the Clipboard window is in front and
the application is switched out.

windowEventHandler

windowEventHandler is the handler for the document windows.  When the
kEventWindowClickContentRegion event type is received, the function doInContent is called.

clipWindowEventHandler

clipWindowEventHandler is the handler for the Clipboard window.  The function
doDrawClipboardWindow is called when the window receives the event types kEventWindowActivated,
kEventWindowDeactivated, kEventWindowDrawContent are received.  When the kEventWindowClose
event type is received, the Clipboard window is disposed of and the text of its item in the
Edit menu is changed.

doAdjustMenus

If the front window is the Clipboard window, the Close item is enabled, otherwise it is
disabled.  If the document contains a picture and that picture is currently selected, the Cut,
Copy, and Clear items are enabled, otherwise they are disabled.

If the scrap contains data of flavour type 'PICT' or flavour type 'TEXT', and the front window
is not the Clipboard window, the Paste item is enabled, otherwise it is disabled.  In this
section, GetCurrentScrap is called to obtain a reference to the current scrap.  This reference
is then passed in two calls to GetScrapFlavorFlags, which determine whether the scrap contains
data of the flavour type 'PICT' and/or flavour type 'TEXT'.  If it does, and if the front
window is not the Clipboard window, the Paste item is enabled.

doOpenDocumentWindows

doOpenDocumentWindows opens the two document windows, creates document structures for each
window, attaches the document structures to the windows and initialises the fields of the
document structures.

The textHdl field of the first window's document structure is assigned a handle to a 'TEXT'
resource and the textHdl field of the second window's document structure is assigned a handle
to a 'PICT' resource.

doCloseWindow

doCloseWindow closes the Clipboard window (the only window that can be closed from within
the program).

If the window is the Clipboard window, the window is disposed of, the global variable which
contains its reference is set to NULL, the global variable which keeps track of whether the
window is showing or hidden is set to false, and the text of the Show/Hide Clipboard menu item
is set to "Show Clipboard".

doInContent

doInContent handles mouse-down events in the content region of a document window.  If the
window contains text or a picture, and if the mouse-down was inside the text or picture, the
text or picture is selected.  If the window contains a text or picture, and if the mouse-down
was outside the text or picture, the text or picture is deselected.

The first two lines get a reference to the front window and a handle to its document structure. 
If the front window is the Clipboard window, the function returns immediately.

doCutCopyCommand

doCutCopyCommand handles the user's choice of the Cut and Copy items in the Edit menu.

The first two lines get a reference to the front window and a handle to that window's document
structure.

If the selectFlag field of the document structure contains false (meaning that the text or
picture has not been selected), the function returns immediately.  (Note that no check is made
as to whether the front window is the Clipboard window because the menu adjustment function
disables the Cut and Copy items when the Clipboard window is the front window, meaning that
this function can never be called when the Clipboard window is in front.)

ClearCurrentScrap attempts to clear the current scrap.  (This call should always be made
immediately the user chooses Cut or Copy.)  If the call is successful, GetCurrentScrap then
gets a reference to the scrap.

If the selected item is text, GetHandleSize gets the size of the text from the window's
document structure.  (In a real application, code which gets the size of the selection would
appear here.)  PutScrapFlavor copies the "selected" text to the scrap.  If the call to
PutScrapFlavor is not successful, an alert is displayed to advise the user of the error.

If the selected item is a picture, GetHandleSize gets the size of the picture from the window's
document structure.  PutScrapFlavor copies the selected picture to the scrap.  If the call to
PutScrapFlavor is not successful, an alert is displayed to advise the user of the error.

If the menu choice was the Cut item, additional action is taken.  Preparatory to a call to
EraseRect, the current graphics port is saved and the front window's port is made the current
port.  DisposeHandle is called to dispose of the text or picture and the document structure's
textHdl or pictureHdl field, and selectFlag field, are set to NULL and false respectively. 
EraseRect then erases the port rectangle.  (In a real application, the action taken in this
block would be to remove the selected text or picture from the document.)

Finally, and importantly, if the Clipboard window has previously been opened by the user,
doDrawClipboardWindow is called to draw the current contents of the scrap in the Clipboard
window.

doPasteCommand

doPasteCommand handles the user's choice of the Paste item from the Edit menu.  Note that
no check is made as to whether the front window is the Clipboard window because the menu
adjustment function disables the Paste item when the Clipboard window is the front window,
meaning that this function can never be called when the Clipboard window is in front.

GetCurrentScrap gets a reference to the scrap.

The first call to GetScrapFlavorFlags determines whether the scrap contains data of flavour
type 'TEXT'.  If so, GetScrapFlavorSize is called to get the size of the 'TEXT' data. 
NewHandle creates a relocatable block of a size equivalent to the 'TEXT' data. 
GetScrapFlavorData is called to copy the 'TEXT' data in the scrap to this block.

TETextBox or DrawThemeTextBox is called to draw the text in a rectangle equal to the port
rectangle minus 40 pixels all round.  If the textHdl field of the window's document structure
does not contain NULL, the associated block is disposed of, following which the handle to the
block containing the new 'TEXT' data is then assigned to the textHdl field.  (In a real
application, this block would copy the text into the document at the insertion point.)  (The
last three lines in this section simply ensure that, if the window's "document" contains text,
it cannot also contain a picture.  This is to prevent a picture overdrawing the text when the
window contents are updated.) 

If the scrap does not contain data of flavour type 'TEXT', GetScrapFlavorFlags is called again
to determine whether the scrap contains data of flavour type 'PICT'.  If it does, much the same
procedure is followed, except that rectangle in which the picture is drawn is extracted from
the 'PICT' data itself and adjusted to the middle of the window via a call to the function
doSetDestRec.

It is emphasized that the scrap is only checked for flavour type 'PICT' if the scrap does not
contain flavour type 'TEXT'.  Thus, if both flavours exist in the scrap, only the 'TEXT'
flavour will be used to draw the Clipboard.

doClearCommand

doClearCommand handles the user's choice of the Clear item in the Edit menu.

Note that no check is made as to whether the front window is the Clipboard window because the
menu adjustment function disables the Clear item when the Clipboard window is the front window.

If the front window's document structure indicates that the window contains text or a picture,
the block containing the TextEdit structure or Picture structure is disposed of and the
relevant field of the document structure is set to NULL.   In addition, the selectFlag field of
the document structure is set to false and the window's port rectangle is erased.

doClipboardCommand

doClipboardCommand handles the user's choice of the Show/Hide Clipboard item in the Edit
menu.

The first line gets a reference to the Edit menu.  This will be required in order to toggle the
Show/Hide Clipboard item's text between Show Clipboard and Hide Clipboard.

The if statement checks whether the Clipboard window has been created.  If not, the Clipboard
window is created by the call to GetNewCWindow, a document structure is created and attached to
the window, the windowType field of the document structure is set to indicate that the window
is of the Clipboard type, the Show/Hide Clipboard menu item text is set, the window's special
window event handler is installed, the window is shown, and a global variable which keeps track
of whether the Clipboard window is currently showing or hidden is set to true.

If the Clipboard window has previously been created, and if the window is currently showing,
the window is hidden, the Clipboard-showing flag is set to false, and the Show/Hide Clipboard
item's text is set to "Show Clipboard".  If the window is not currently showing, the window is
made visible, the Clipboard-showing flag is set to true, and the Show/Hide Clipboard item's
text is set to "Hide Clipboard".

doDrawClipboardWindow

doDrawClipboardWindow draws the contents of the scrap in the Clipboard window.  It
supports the drawing of both 'PICT' and 'TEXT' flavour type data.

The first four lines save the current graphics port, make the Clipboard window's graphics port
the current graphics port and erase the window's content region.

DrawThemeWindowHeader draws a window header in the top of the window.  Text describing the type
of data in the scrap will be drawn in this header.

The text mode for text drawing is set at the next four lines, following which "Clipboard
Contents:" is drawn in the header.

The code for getting a reference to the current scrap, checking for the 'TEXT' and 'PICT'
flavour types, getting the flavour size, getting the flavour data, and drawing the text and
picture in the window is much the same as in the function doPasteCommand.  The differences are:
the rectangle in which the text is drawn is the port rectangle minus two pixels all round and
with the top further adjusted downwards by the height of the window header; the left/top of the
rectangle in which the picture is drawn is two pixels inside the left side of the content
region and two pixels below the window header respectively; the words "Text" or "Picture" are
drawn in the window header as appropriate.

Note that, as was the case in the function doPasteCommand, the scrap is only checked for
flavour type 'PICT' if the scrap does not contain flavour type 'TEXT'.  Thus, if both flavours
exist in the scrap, only the 'TEXT' flavour will be used to draw the Clipboard.

doDrawDocumentWindow

doDrawDocumentWindow draws the text or picture belonging to that window in the window.  It
is called when the kEventWindowDrawContent event type is received for the window.