AcornDrawFilter Class Reference

Encapsulates an RISC OS Draw input filter system. More...

#include <drawfltr.h>

Inheritance diagram for AcornDrawFilter:

List of all members.

Public Member Functions
	AcornDrawFilter ()
	Filter constructor - this initialises the default attributes and the input buffer.
	~AcornDrawFilter ()
	Destructor for the filter - this deallocates the input buffer.
BOOL	Init ()
	Initialise the filter (attaches a DrawOILFilter object).
virtual BOOL	IsDefaultDocRequired (const TCHAR *pcszPathName)
	Works out if opening a file of this type requires a default document to be loaded. If the file format supplies the document then return FALSE otherwise return TRUE. An example would be opening a bitmap file. This has no document defined in the file format and so we need to laod the default document before importing the bitmap into this file. In this version we return TRUE as either this format has no page size or nobody has implemented it yet.
INT32	HowCompatible (PathName &Filename, ADDR HeaderStart, UINT32 HeaderSize, UINT32 FileSize)
	Analyse a file to see if it is an Acorn Draw file - at present this is done by checking to see if the first four bytes are "Draw".
BOOL	DoImport (SelOperation *Op, CCLexFile *, Document *DestDoc, BOOL AutoChosen, ImportPosition *Pos=NULL, KernelBitmap **ppImportedBitmap=NULL, DocCoord *pPosTranslate=NULL, String_256 *=NULL)
	Import the named Acorn draw file into the specified document. As yet, only path and group objects are handled. Tagged objects are handled correctly, so, e.g. TableMate files can be loaded by Camelot (although the results are not very interesting). Currently, the data is always positioned on the first page of the first spread in the first chapter. If the read is successful, the End() function of the 'Op' operation is called, otherwise it is not called.
BOOL	DoExport (Operation *, CCLexFile *, PathName *, Document *, BOOL)
	None; this is a dummy function as we don't export in Acorn Draw format (yet).
Private Member Functions
	CC_DECLARE_DYNAMIC (AcornDrawFilter)
BOOL	PrepareToImport ()
	Sets up the Draw filter so it can read in a Draw file.
void	CleanUpAfterImport ()
	Delete dynamic objects used in the import process.
void	TransformCoord (DocCoord &C)
BOOL	ReadFileHeader ()
	Read the header block of an Acorn Draw file.
BOOL	ReadObjectHeader ()
	This function reads in the header of a Draw object from the input file, and stores the result in the ObjectHeader member variable. Using the data in the header it then sets up the HeaderSize and DataSize member variables correctly. It is not ok just to use sizeof(ObjectHeader) as this is not always accurate because some objects in Draw files has stupid headers which are smaller than the standard size, so we have to compensate for this. In such cases we also have to rewind the file so we are in the correct position to read in the data following the header.
BOOL	ReadObjectData ()
	Read in the data for a Draw object. The data is stored in the buffer pointed to by the member variable DataBuf. If the buffer is not big enough, it is automagically expanded.
BOOL	ProcessObject ()
	Routes the object data to the appropriate function to be processed, according to the tag in the object's header data. If the object is not understood, then the data is simply discarded.
BOOL	ProcessPath ()
	Read in the data for a Draw path object, and convert it to an equivalent Camelot NodePath object, and add it to the node pointed to by the pNode member variable.
BOOL	ProcessGroup ()
BOOL	ProcessTaggedObject ()
	Read in and process a tagged object from a Draw file. A tagged object is a normal object with some arbitrary data following it. This function can handle the tagged object being a group which itself contains tagged objects, and so on.
BOOL	SkipObject ()
	Skips past the data for this object, usually because the object is not supported by this filter and/or Camelot.
BOOL	AddAttributes (NodePath *pPath, DrawPathHeader *pHeader)
	Add attributes to the path object specified. The attributes are optimised so that if they are the same as the document's default attributes, they are not applied. The attributes applied are line and fill colour, and line style.
Private Attributes
CCLexFile *	DrawFile
BOOL	eof
Layer *	pLayer
Page *	pPage
Node *	pNode
BOOL	ComplexPath
BOOL	NoAttributes
DocCoord	Origin
DrawFileHeader	FileHeader
DrawObjectHeader	ObjectHeader
ADDR	DataBuf
UINT32	DataBufSize
UINT32	HeaderSize
UINT32	DataSize
INT32	BytesRead
INT32	LastProgressUpdate

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Detailed Description

Encapsulates an RISC OS Draw input filter system.

Author:

Tim_Browse (Xara Group Ltd) <camelotdev@xara.com>

Date:

13/10/93

Definition at line 194 of file drawfltr.h.

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Constructor & Destructor Documentation

AcornDrawFilter::AcornDrawFilter (   )

Filter constructor - this initialises the default attributes and the input buffer. Author: Tim_Browse (Xara Group Ltd) <camelotdev@xara.com> Date: 18/11/93 Definition at line 305 of file drawfltr.cpp. { // Set up filter descriptions. FilterName.Load(_R(IDT_DRAW_FILTERNAME)); FilterInfo.Load(_R(IDT_DRAW_FILTERINFO)); FilterID = FILTERID_ACORN_DRAW; #ifndef STANDALONE Flags.CanImport = TRUE; Flags.CanExport = FALSE; #else Flags.CanImport = FALSE; Flags.CanExport = FALSE; #endif #if 0 // No attributes yet DefLineWidthAttr = NULL; DefLineColAttr = NULL; DefFillColAttr = NULL; #endif // No buffer yet DataBuf = NULL; DataBufSize = 0; };

AcornDrawFilter::~AcornDrawFilter (   )

Destructor for the filter - this deallocates the input buffer. Author: Tim_Browse (Xara Group Ltd) <camelotdev@xara.com> Date: 18/11/93 Definition at line 343 of file drawfltr.cpp. { // Clean up our input buffer CCFree(DataBuf); }

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Member Function Documentation

BOOL AcornDrawFilter::AddAttributes (  NodePath *  pPath, DrawPathHeader *  pHeader )  [private]

Add attributes to the path object specified. The attributes are optimised so that if they are the same as the document's default attributes, they are not applied. The attributes applied are line and fill colour, and line style. Author: Tim_Browse (Xara Group Ltd) <camelotdev@xara.com> Date: 18/11/93 Parameters: pPath  - pointer to the NodePath object to add attributes to. [INPUTS] pHeader - pointer to the Draw file object header which describes the path attributes. Returns: TRUE if the attributes were added ok, FALSE if not. Errors: Fails (returns FALSE) if not enough memory to add attributes. Scope: Private Definition at line 1160 of file drawfltr.cpp. { // Add attributes to the path, if they are different from the default... // First set the current attributes. // Fill colour if (pHeader->FillColour.Data.ColourValue == DRAW_TRANSPARENT) { pPath->InkPath.IsFilled = FALSE; } else { pPath->InkPath.IsFilled = TRUE; DocColour FillColour(pHeader->FillColour.Data.Component.Red, pHeader->FillColour.Data.Component.Green, pHeader->FillColour.Data.Component.Blue); if (!SetFillColour(FillColour)) return FALSE; } // Line colour if (pHeader->LineColour.Data.ColourValue == DRAW_TRANSPARENT) { if (!SetLineColour(DocColour(COLOUR_TRANS))) return FALSE; } else { DocColour LineColour(pHeader->LineColour.Data.Component.Red, pHeader->LineColour.Data.Component.Green, pHeader->LineColour.Data.Component.Blue); if (!SetLineColour(LineColour)) return FALSE; } // Line width // Convert from Draw units (1/640 of a point) to Camelot units (millipoints_ // Hence it involves multiplying by 1000/640, which equates to 25/16. pHeader->LineWidth *= 25; pHeader->LineWidth /= 16; if (!SetLineWidth(pHeader->LineWidth)) return FALSE; // Now add attributes if they are different from the defaults. // If not filled, then set the ignore bit on the fill attribute. if (!pPath->InkPath.IsFilled) CurrentAttrs[ATTR_FILLGEOMETRY].Ignore = TRUE; // Add attributes to the path, if they are different from the default... BOOL Result = AttributeManager::ApplyBasedOnDefaults(pPath, CurrentAttrs); // Enable the fill attribute again CurrentAttrs[ATTR_FILLGEOMETRY].Ignore = FALSE; // Return success or failure return Result; }

AcornDrawFilter::CC_DECLARE_DYNAMIC (  AcornDrawFilter   )  [private]

void AcornDrawFilter::CleanUpAfterImport (  void   )  [private]

Delete dynamic objects used in the import process. Author: Tim_Browse (Xara Group Ltd) <camelotdev@xara.com> Date: 24/02/94 See also: AcornDrawFilter::PrepareToImport; AcornDrawFilter::DoImport Definition at line 478 of file drawfltr.cpp. { DeleteCurrentAttrs(); DrawFile = NULL; CCFree(DataBuf); DataBuf = NULL; DataBufSize = 0; }

BOOL AcornDrawFilter::DoExport (  Operation *  , CCLexFile *  , PathName *  , Document *  , BOOL  )  [virtual]

None; this is a dummy function as we don't export in Acorn Draw format (yet). Author: Tim_Browse (Xara Group Ltd) <camelotdev@xara.com> Date: 28/03/94 Parameters: As  base class version. [INPUTS] Returns: FALSE. See also: Filter::DoExport; Filter Reimplemented from Filter. Definition at line 1238 of file drawfltr.cpp. { // We don't export in Draw format return FALSE; }

BOOL AcornDrawFilter::DoImport (  SelOperation *  Op, CCLexFile *  pFile, Document *  DestDoc, BOOL  AutoChosen, ImportPosition *  Pos = NULL, KernelBitmap **  ppImportedBitmap = NULL, DocCoord *  pPosTranslate = NULL, String_256 *  URL = NULL )  [virtual]

Import the named Acorn draw file into the specified document. As yet, only path and group objects are handled. Tagged objects are handled correctly, so, e.g. TableMate files can be loaded by Camelot (although the results are not very interesting). Currently, the data is always positioned on the first page of the first spread in the first chapter. If the read is successful, the End() function of the 'Op' operation is called, otherwise it is not called. Author: Tim_Browse (Xara Group Ltd) <camelotdev@xara.com> Date: 18/11/93 Parameters: Op  - pointer to the operation that this read process is associated with. [INPUTS] pFile - The file that we are trying to import DestDoc - pointer to the document to insert the Draw file data into. AutoChosen - Pos - ppImportedBitmap - this is used mainly in the bitfltr.cpp for the HTML import filter. HTMLFilter::DoImport() needs a pointer to a kernel bitmap to set the background bitmap up into Camelot. pPosTranslate - This is used too by the HTMLFilter in order to do a formatting. URL - original URL of the imported file Returns: TRUE if the read was successful, FALSE if not. Errors: Unable to open file, corrupted document tree found. Reimplemented from Filter. Definition at line 519 of file drawfltr.cpp. { // Let's get ready if (!PrepareToImport()) return FALSE; // Make sure that there is a layer to put the bitmap onto if (!MakeSureLayerExists(DestDoc)) // There is no layer and one could not be made, so we will have to fail return FALSE; // Find the layer on the first page of this document... pLayer = GetActiveLayer(DestDoc); ENSURE(pLayer != NULL, "Spread has no active layer"); // pNode is where new objects will go - they all go into a group so the user // can easily drag the imported Draw file around. They can then ungroup it afterwards // if they want. NodeGroup *pDrawGroup = new NodeGroup; ERRORIF(pDrawGroup == NULL, _R(IDT_DRAW_NOMEMORY), FALSE); pNode = pDrawGroup; Spread *pSpread; if (Pos == NULL) { // For now, position Draw objects on 1st page of spread 1 PORTNOTE("spread", "Multi-spread warning!") pSpread = GetFirstSpread(DestDoc); pPage = (Page *) pSpread->FindFirstPageInSpread(); ENSURE(pPage->IsKindOf(CC_RUNTIME_CLASS(Page)), "AcornDrawFilter::Read(): Could not find first Page"); // Use bottom left of page as origin DocRect PageRect = pPage->GetPageRect(); Origin = PageRect.lo; } else { pSpread = Pos->pSpread; Origin = Pos->Position; } // No complex path initially ComplexPath = FALSE; // Make a note of the disk file DrawFile = pFile; // Disable exceptions and error reporting for this file - we'll do it ourselves DrawFile->SetReportErrors(FALSE); DrawFile->SetThrowExceptions(FALSE); // Find out the size of the file, in bytes. INT32 filesize = DrawFile->Size(); // Initialise eof = FALSE; // Set the progress indicator, this next bit might take a while. String_64 ImportMessage(_R(IDT_IMPORTMSG_ACORNDRAW)); ImportMessage = GetImportProgressString(pFile, _R(IDT_IMPORTMSG_ACORNDRAW)); BeginSlowJob(filesize, TRUE, &ImportMessage); BytesRead = 0; LastProgressUpdate = 0; // Find out details on the file ReadFileHeader(); // Check that this is an Acorn Draw file...the first four characters in the file // should be "Draw". If we've been chosen automatically, then don't bother as we've // already checked this. if (DrawFile->eof() || (!AutoChosen && (camStrncmp(FileHeader.Ident, "Draw", 4) != 0))) { // Could not find the ident header - close the file, and return error. EndSlowJob(); CleanUpAfterImport(); ERROR(_R(IDT_DRAW_NOTADRAWFILE), FALSE); } // Remember file errors BOOL Error = FALSE; // Process each object in the file do { // Read and process each object if (ReadObjectHeader()) { // Header read ok so there is another object to process if (!ProcessObject()) // Unable to process object - set error flag Error = TRUE; } } while ((BytesRead < filesize) && !Error); // All work has been completed . . . EndSlowJob(); // All done BOOL Failed = Error && (BytesRead < filesize); // Free up dynamic objects used for import CleanUpAfterImport(); // If the load failed for any reason, delete the subtree we have created; otherwise // graft it into the tree. if (Failed) { // Failed - delete the sub-tree we just created, free the buffer, and return error. pDrawGroup->CascadeDelete(); delete pDrawGroup; return FALSE; } else { // It worked - add the node into the tree // Remember current bounding rectangle of the group DocRect BoundsRect = pDrawGroup->GetBoundingRect(TRUE); if (Pos != NULL) { // It should be centred on the given position... DocCoord Centre; Centre.x = (BoundsRect.lo.x + BoundsRect.hi.x) / 2; Centre.y = (BoundsRect.lo.y + BoundsRect.hi.y) / 2; Trans2DMatrix Xlate(Pos->Position.x - Centre.x, Pos->Position.y - Centre.y); pDrawGroup->Transform(Xlate); } // Insert the node and invalidate its region if (!Op->DoInsertNewNode(pDrawGroup, pSpread, TRUE)) { // It didn't work - delete the sub-tree we just created pDrawGroup->CascadeDelete(); delete pDrawGroup; pDrawGroup = NULL; } } // All ok return TRUE; }

INT32 AcornDrawFilter::HowCompatible (  PathName &  Filename, ADDR  HeaderStart, UINT32  HeaderSize, UINT32  FileSize )  [virtual]

Analyse a file to see if it is an Acorn Draw file - at present this is done by checking to see if the first four bytes are "Draw". Author: Tim_Browse (Xara Group Ltd) <camelotdev@xara.com> Date: 21/03/94 Parameters: Filename  - name of the file. [INPUTS] HeaderStart - Address of the first few bytes of the file. HeaderSize - the number of bytes in the header pointed to by FileStart. FileSize - the size of the whole file, in bytes. Returns: Compatibility: 0 => Not a Draw file; 10 => It is a Draw file See also: AcornDrawFilter Reimplemented from Filter. Definition at line 419 of file drawfltr.cpp. { PORTNOTE("byteorder", "TODO: Check byte ordering") if (camStrncmp((char *) HeaderStart, "Draw", 4) == 0) { // It's a Draw file. return 10; } // It's not a Draw file. return 0; }

BOOL AcornDrawFilter::Init (  void   )  [virtual]

Initialise the filter (attaches a DrawOILFilter object). Author: Tim_Browse (Xara Group Ltd) <camelotdev@xara.com> Date: 18/11/93 Returns: Always TRUE at the moment. See also: DrawOILFilter Implements Filter. Definition at line 362 of file drawfltr.cpp. { // Get the OILFilter object pOILFilter = new DrawOILFilter(this); if (pOILFilter == NULL) return FALSE; // All ok return TRUE; }

BOOL AcornDrawFilter::IsDefaultDocRequired (  const TCHAR *  pcszPathName  )  [virtual]

Works out if opening a file of this type requires a default document to be loaded. If the file format supplies the document then return FALSE otherwise return TRUE. An example would be opening a bitmap file. This has no document defined in the file format and so we need to laod the default document before importing the bitmap into this file. In this version we return TRUE as either this format has no page size or nobody has implemented it yet. Author: Neville_Humphrys (Xara Group Ltd) <camelotdev@xara.com> Date: 16/10/95 Parameters: pcszPathName  pointer to the pathname to check [INPUTS] Returns: TRUE if the filter requires a default document, FALSE if not. See also: Filter; Filter::IsDefaultDocRequired; CCamDoc::OnOpenDocument; FilterFamily::DoImport; Filter::DoImport; Reimplemented from Filter. Definition at line 393 of file drawfltr.cpp. { // No need to check the pathname, just return TRUE as all currently known bitmap filters // will require the default document. return TRUE; }

BOOL AcornDrawFilter::PrepareToImport (   )  [private]

Sets up the Draw filter so it can read in a Draw file. Author: Tim_Browse (Xara Group Ltd) <camelotdev@xara.com> Date: 22/02/94 Returns: TRUE if it succeeds, FALSE if not. Definition at line 446 of file drawfltr.cpp. { // Get a default set of attributes for ink objects. if (!SetUpCurrentAttrs()) return FALSE; // Shouldn't have a data buffer at this point ENSURE(DataBuf == NULL, "DataBuf is non-NULL in PrepareToImport()"); // No objects read yet HeaderSize = 0; DataSize = 0; // Get a Diskfile object DrawFile = NULL; // Ok so far return TRUE; }

BOOL AcornDrawFilter::ProcessGroup (   )  [private]

Definition at line 956 of file drawfltr.cpp. { // Remembers file read errors BOOL Error = FALSE; // Skip past the group name DrawFile->seekIn(DRAW_GROUPNAMESIZE, ios::cur); BytesRead += DRAW_GROUPNAMESIZE; // Create a group node, and make pNode point to it, so that all objects in the group // are attached to it. NodeGroup *pGroup = new NodeGroup(pNode, LASTCHILD); if (pGroup == NULL) { // Not enough heap to create group ERROR(_R(IDT_DRAW_NOMEMORY), FALSE); } Node *pOldNode = pNode; pNode = pGroup; // Work out where the end of the group is FilePos EndPos = DrawFile->tellIn(); DataSize -= DRAW_GROUPNAMESIZE; EndPos += DataSize; // Read (and process) each object in the group, until the end of group or end of file // is found. do { // Read in and process the next object if (!(ReadObjectHeader() && ProcessObject())) Error = TRUE; } while (!DrawFile->eof() && (DrawFile->tellIn() < EndPos)); // Restore the node pointer to the parent of this group pNode = pOldNode; // If EOF found, then the group was truncated, so return error. // Also return error if object reading failed in any way. if (Error) // Error has already been set return FALSE; if (DrawFile->eof()) ERROR1(FALSE, _R(IDT_DRAW_BADSYNTAX)); // Must have worked return TRUE; }

BOOL AcornDrawFilter::ProcessObject (  void   )  [private]

Routes the object data to the appropriate function to be processed, according to the tag in the object's header data. If the object is not understood, then the data is simply discarded. Author: Tim_Browse (Xara Group Ltd) <camelotdev@xara.com> Date: 19/11/93 Returns: TRUE if the object was processed with no errors, FALSE if not. Errors: - See also: AcornDrawFilter::ProcessPath; AcornDrawFilter::ProcessGroup; AcornDrawFilter::ProcessTaggedObject; AcornDrawFilter::SkipObject Scope: Private Definition at line 771 of file drawfltr.cpp. { if (BytesRead > (LastProgressUpdate + 2048)) { LastProgressUpdate = BytesRead; if (!ContinueSlowJob(BytesRead)) return FALSE; } switch (ObjectHeader.Type) { case DRAWOBJECT_PATH: return ProcessPath(); case DRAWOBJECT_GROUP: return ProcessGroup(); case DRAWOBJECT_TAGGED: return ProcessTaggedObject(); default: return SkipObject(); } }

BOOL AcornDrawFilter::ProcessPath (   )  [private]

Read in the data for a Draw path object, and convert it to an equivalent Camelot NodePath object, and add it to the node pointed to by the pNode member variable. Author: Tim_Browse (Xara Group Ltd) <camelotdev@xara.com> Date: 18/11/93 Returns: TRUE if the path object is read and converted ok, FALSE if not. Errors: File reading error, out of memory. See also: AcornDrawFilter::ProcessObject Scope: Private Definition at line 805 of file drawfltr.cpp. { // Attempt to read the data for this object if (!ReadObjectData()) return FALSE; // Construct the path and add it to our group node... // Create a new NodePath pbject NodePath *pPath = new NodePath(pNode, LASTCHILD); if ((pPath == NULL) || (!pPath->SetUpPath())) { // Couldn't initialise path - delete path (if created) and return error. delete pPath; ERROR(_R(IDT_DRAW_NOMEMORY), FALSE); } // Position tag at start of path. pPath->InkPath.FindStartOfPath(); // Examine path header info DrawPathHeader *pHeader = (DrawPathHeader *) DataBuf; // Find first path element DrawPathElement *pElement = (DrawPathElement *) (pHeader + 1); // Skip dash pattern if present if (pHeader->Style.Data.DashPresent) { DashPatternHeader *pDashPattern = (DashPatternHeader *) pElement; pElement = (DrawPathElement *) ( ((ADDR) pElement) + sizeof(DashPatternHeader) + (4 * pDashPattern->NumElements) ); } // Process path elements until no more data is left. UINT32 BytesUsed = 0; INT32 Tag = (pElement->Tag) & 0xFF; while (Tag != DRAWTAG_ENDOFPATH) { switch (Tag) { case DRAWTAG_MOVETO: BytesUsed = SIZEOF_MOVETO; TransformCoord(pElement->Coords[0]); // Insert a moveto into the path if (!pPath->InkPath.InsertMoveTo(pElement->Coords[0])) // Not enough dynamic heap to insert the moveto command goto NoMemory; break; case DRAWTAG_LINETO: BytesUsed = SIZEOF_LINETO; TransformCoord(pElement->Coords[0]); // Insert a lineto into the path if (!pPath->InkPath.InsertLineTo(pElement->Coords[0])) // Not enough dynamic heap to insert the lineto command goto NoMemory; break; case DRAWTAG_CURVETO: BytesUsed = SIZEOF_CURVETO; TransformCoord(pElement->Coords[0]); TransformCoord(pElement->Coords[1]); TransformCoord(pElement->Coords[2]); // Insert a curveto into the path if (!pPath->InkPath.InsertCurveTo(pElement->Coords[0], pElement->Coords[1], pElement->Coords[2])) // Not enough dynamic heap to insert the curveto command goto NoMemory; break; case DRAWTAG_CLOSESUBPATH: BytesUsed = SIZEOF_CLOSESUBPATH; // Terminate sub-path if (!pPath->InkPath.CloseSubPath()) // Not enough dynamic heap to insert the final element of the path goto NoMemory; break; default: // Don't understand this element! ERROR1(FALSE, _R(IDT_DRAW_BADSYNTAX)); } // Move pointer onto next path element pElement = (DrawPathElement *) (((ADDR) pElement) + BytesUsed); Tag = (pElement->Tag) & 0xFF; } // check that the path is OK if(!pPath->InkPath.EnsureValid()) { // no, it's completely knackered pPath->UnlinkNodeFromTree(); delete pPath; // don't error about it. return TRUE; } // Use the path header to set the attributes on this path AddAttributes(pPath, pHeader); // Terminate path properly. pPath->InvalidateBoundingRect(); // All ok return TRUE; NoMemory: // Error - Out of memory while reading Draw file // Destroy any half-created paths if (pPath != NULL) { pPath->CascadeDelete(); delete pPath; } // Set the error for the caller to report ERROR(_R(IDT_DRAW_NOMEMORY), FALSE); }

BOOL AcornDrawFilter::ProcessTaggedObject (   )  [private]

Read in and process a tagged object from a Draw file. A tagged object is a normal object with some arbitrary data following it. This function can handle the tagged object being a group which itself contains tagged objects, and so on. Author: Tim_Browse (Xara Group Ltd) <camelotdev@xara.com> Date: 19/11/93 Returns: TRUE if the tagged object is read and process ok, FALSE if not. Errors: Out of memory, error processing the tagged object. See also: AcornDrawFilter::ProcessObject; AcornDrawFilter::ReadObjectHeader Scope: Private Definition at line 1028 of file drawfltr.cpp. { // Remembers file read errors BOOL Error = FALSE; // Skip past the object tag DrawFile->seekIn(DRAW_TAGSIZE, ios::cur); BytesRead += DRAW_TAGSIZE; // Work out where the end of the tagged object is FilePos EndPos = DrawFile->tellIn(); DataSize -= DRAW_TAGSIZE; EndPos += DataSize; // Read (and process) the object if (!(ReadObjectHeader() && ProcessObject())) // Something went wrong so return error return FALSE; // Skip the word-aligned data following the object DrawFile->seekIn(EndPos); BytesRead = EndPos; // All ok return TRUE; }

BOOL AcornDrawFilter::ReadFileHeader (   )  [private]

Read the header block of an Acorn Draw file. Author: Tim_Browse (Xara Group Ltd) <camelotdev@xara.com> Date: 18/11/93 Returns: TRUE if the read is successful, FALSE if an error was encountered. See also: AcornDrawFilter::ReadObjectHeader Scope: Private Definition at line 683 of file drawfltr.cpp. { DrawFile->read(&FileHeader, sizeof(FileHeader)); BytesRead += sizeof(FileHeader); return TRUE; }

BOOL AcornDrawFilter::ReadObjectData (   )  [private]

Read in the data for a Draw object. The data is stored in the buffer pointed to by the member variable DataBuf. If the buffer is not big enough, it is automagically expanded. Author: Tim_Browse (Xara Group Ltd) <camelotdev@xara.com> Date: 18/11/93 Returns: TRUE if the data was read ok, FALSE if not. Errors: Out of memory. See also: AcornDrawFilter::ReadObjectHeader Scope: Private Definition at line 1104 of file drawfltr.cpp. { // Obtain a buffer to read the data into, if we haven't got one already if (DataSize > DataBufSize) { // Buffer is not big enough - try to expand it. // Don't overwrite DataBuf pointer unless we know the realloc succeeds, otherwise // we won't be able to free the old buffer if it fails. ADDR NewBuf = (ADDR) CCRealloc(DataBuf, DataSize); // Failed to expand buffer - return error. ERRORIF(NewBuf == NULL, _R(IDT_DRAW_NOMEMORY), FALSE); // Buffer was expanded ok - update the buffer pointer/size variables. DataBufSize = DataSize; DataBuf = NewBuf; } // To get this far, we must have a buffer big enough to hold the object, so read it in... // NB we check that we read the correct number of bytes. FilePos BeforePos = DrawFile->tell(); DrawFile->read(DataBuf, DataSize); BytesRead += DataSize; FilePos AfterPos = DrawFile->tell(); if ((UINT32) (AfterPos-BeforePos) != DataSize) { ERROR3_PF(("Bytes read - actual: %d, planned: %d", (AfterPos-BeforePos), DataSize)); // If EOF found, then an error has occured ERROR1(FALSE, _R(IDT_DRAW_BADSYNTAX)); } // Ok if we got here. return TRUE; }

BOOL AcornDrawFilter::ReadObjectHeader (   )  [private]

This function reads in the header of a Draw object from the input file, and stores the result in the ObjectHeader member variable. Using the data in the header it then sets up the HeaderSize and DataSize member variables correctly. It is not ok just to use sizeof(ObjectHeader) as this is not always accurate because some objects in Draw files has stupid headers which are smaller than the standard size, so we have to compensate for this. In such cases we also have to rewind the file so we are in the correct position to read in the data following the header. Author: Tim_Browse (Xara Group Ltd) <camelotdev@xara.com> Date: 18/11/93 Returns: TRUE if the header was read ok, FALSE if not. Errors: If the EOF is found. See also: AcornDrawFilter::ReadObjectData; AcornDrawFilter::ReadFileHeader Scope: Private Definition at line 711 of file drawfltr.cpp. { // Set default header size FilePos BeforePos = DrawFile->tell(); HeaderSize = sizeof(ObjectHeader); DrawFile->read(&ObjectHeader, sizeof(ObjectHeader)); BytesRead += sizeof(ObjectHeader); FilePos AfterPos = DrawFile->tell(); if ((UINT32) (AfterPos-BeforePos) != sizeof(ObjectHeader)) { ERROR3_PF(("Header bytes read - actual: %d, planned: %d", (AfterPos-BeforePos), sizeof(ObjectHeader))); // If EOF found, then an error has occured ERROR1(FALSE, _R(IDT_DRAW_BADSYNTAX)); } // Check for silly objects that don't have a bounding box, and move the input pointer // back to cope with this. switch (ObjectHeader.Type) { case DRAWOBJECT_FONTTABLE: // Move back over the bounding box fields (which don't really exist) FilePos Pos = DrawFile->tellIn(); // Bounding box fields take up 16 bytes in Acorn Draw files. DrawFile->seekIn(Pos - 16); BytesRead -= 16; // Adjust header size HeaderSize -= 16; break; } DataSize = ObjectHeader.Size - HeaderSize; // If eof not found, then no error return TRUE; }

BOOL AcornDrawFilter::SkipObject (   )  [private]

Skips past the data for this object, usually because the object is not supported by this filter and/or Camelot. Author: Tim_Browse (Xara Group Ltd) <camelotdev@xara.com> Date: 18/11/93 Returns: TRUE always at present. See also: AcornDrawFilter::ProcessObject Scope: Private Definition at line 1069 of file drawfltr.cpp. { if (IsUserName("Tim")) { TRACE( _T("Skipping unsupported object (type %d, size %d)\n"), ObjectHeader.Type, ObjectHeader.Size); } // Skip the number of bytes specified in the current object's header FilePos Pos = DrawFile->tellIn(); Pos += DataSize; DrawFile->seekIn(Pos); BytesRead = Pos; // No error checking yet return TRUE; }

void AcornDrawFilter::TransformCoord (  DocCoord &  C  )  [inline, private]

Definition at line 246 of file drawfltr.h. { C.x *= 25; C.x /= 16; C.x += Origin.x; C.y *= 25; C.y /= 16; C.y += Origin.y; };

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Member Data Documentation

INT32 AcornDrawFilter::BytesRead [private]

Definition at line 270 of file drawfltr.h.

BOOL AcornDrawFilter::ComplexPath [private]

Definition at line 236 of file drawfltr.h.

ADDR AcornDrawFilter::DataBuf [private]

Definition at line 253 of file drawfltr.h.

UINT32 AcornDrawFilter::DataBufSize [private]

Definition at line 254 of file drawfltr.h.

UINT32 AcornDrawFilter::DataSize [private]

Definition at line 256 of file drawfltr.h.

CCLexFile* AcornDrawFilter::DrawFile [private]

Definition at line 221 of file drawfltr.h.

BOOL AcornDrawFilter::eof [private]

Definition at line 224 of file drawfltr.h.

DrawFileHeader AcornDrawFilter::FileHeader [private]

Definition at line 248 of file drawfltr.h.

UINT32 AcornDrawFilter::HeaderSize [private]

Definition at line 255 of file drawfltr.h.

INT32 AcornDrawFilter::LastProgressUpdate [private]

Definition at line 271 of file drawfltr.h.

BOOL AcornDrawFilter::NoAttributes [private]

Definition at line 239 of file drawfltr.h.

DrawObjectHeader AcornDrawFilter::ObjectHeader [private]

Definition at line 252 of file drawfltr.h.

DocCoord AcornDrawFilter::Origin [private]

Definition at line 242 of file drawfltr.h.

Layer* AcornDrawFilter::pLayer [private]

Definition at line 227 of file drawfltr.h.

Node* AcornDrawFilter::pNode [private]

Definition at line 233 of file drawfltr.h.

Page* AcornDrawFilter::pPage [private]

Definition at line 230 of file drawfltr.h.

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The documentation for this class was generated from the following files:

• Kernel/drawfltr.h (r1785/r1282)
• Kernel/drawfltr.cpp (r1785/r1282)

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