MythTV: ParseText.cpp Source File

00001 /* ParseText.cpp
00002 
00003    Copyright (C)  David C. J. Matthews 2004, 2008  dm at prolingua.co.uk
00004 
00005    This program is free software; you can redistribute it and/or
00006    modify it under the terms of the GNU General Public License
00007    as published by the Free Software Foundation; either version 2
00008    of the License, or (at your option) any later version.
00009 
00010    This program is distributed in the hope that it will be useful,
00011    but WITHOUT ANY WARRANTY; without even the implied warranty of
00012    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00013    GNU General Public License for more details.
00014 
00015    You should have received a copy of the GNU General Public License
00016    along with this program; if not, write to the Free Software
00017    Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
00018    Or, point your browser to http://www.gnu.org/copyleft/gpl.html
00019 
00020 */
00021 
00022 /*
00023 Parser for the textual form of MHEG5.
00024 This is very basic and is only there to enable some test programs to be run.
00025 */
00026 
00027 #include "ParseText.h"
00028 #include "ParseNode.h"
00029 #include "BaseClasses.h"
00030 #include "ASN1Codes.h"
00031 #include "Root.h"
00032 #include "Groups.h"
00033 #include <ctype.h>
00034 #include "Ingredients.h" // For GetEventType
00035 #include "Text.h" // For GetJustification etc
00036 #include "Engine.h"
00037 #include "Logging.h"
00038 
00039 
00040 #ifndef WIN32
00041 #define stricmp strcasecmp
00042 #endif
00043 
00044 
00045 MHParseText::MHParseText(QByteArray &program)
00046 {
00047     m_data = program;
00048     m_lineCount = 1;
00049     m_String = (unsigned char*)malloc(100); // Initial size - may grow.
00050     m_p = 0;
00051  }
00052 
00053 MHParseText::~MHParseText()
00054 {
00055     free(m_String);
00056 }
00057 
00058 // Get the next character.
00059 void MHParseText::GetNextChar()
00060 {
00061     if (m_p >= m_data.size())
00062         m_ch = EOF;
00063     else m_ch = m_data[m_p++];
00064 }
00065 
00066 // Maximum length of a tag (i.e. a symbol beginning with a colon). Actually  the longest is around 22 chars.
00067 #define MAX_TAG_LENGTH  30
00068 
00069 const char *rchTagNames[] =
00070 {
00071     ":Application",
00072     ":Scene",
00073     ":StdID",
00074     ":StdVersion",
00075     ":ObjectInfo",
00076     ":OnStartUp",
00077     ":OnCloseDown",
00078     ":OrigGCPriority",
00079     ":Items",
00080     ":ResidentPrg",
00081     ":RemotePrg",
00082     ":InterchgPrg",
00083     ":Palette",
00084     ":Font",  // Occurs twice.
00085     ":CursorShape",
00086     ":BooleanVar",
00087     ":IntegerVar",
00088     ":OStringVar",
00089     ":ObjectRefVar",
00090     ":ContentRefVar",
00091     ":Link",
00092     ":Stream",
00093     ":Bitmap",
00094     ":LineArt",
00095     ":DynamicLineArt",
00096     ":Rectangle",
00097     ":Hotspot",
00098     ":SwitchButton",
00099     ":PushButton",
00100     ":Text",
00101     ":EntryField",
00102     ":HyperText",
00103     ":Slider",
00104     ":TokenGroup",
00105     ":ListGroup",
00106     ":OnSpawnCloseDown",
00107     ":OnRestart",
00108     "", // Default attributes - encoded as a group in binary
00109     ":CharacterSet",
00110     ":BackgroundColour",
00111     ":TextCHook",
00112     ":TextColour",
00113     ":Font",
00114     ":FontAttributes",
00115     ":InterchgPrgCHook",
00116     ":StreamCHook",
00117     ":BitmapCHook",
00118     ":LineArtCHook",
00119     ":ButtonRefColour",
00120     ":HighlightRefColour",
00121     ":SliderRefColour",
00122     ":InputEventReg",
00123     ":SceneCS",
00124     ":AspectRatio",
00125     ":MovingCursor",
00126     ":NextScenes",
00127     ":InitiallyActive",
00128     ":CHook",
00129     ":OrigContent",
00130     ":Shared",
00131     ":ContentSize",
00132     ":CCPriority",
00133     "" , // Link condition - always replaced by EventSource, EventType and EventData
00134     ":LinkEffect",
00135     ":Name",
00136     ":InitiallyAvailable",
00137     ":ProgramConnectionTag",
00138     ":OrigValue",
00139     ":ObjectRef",
00140     ":ContentRef",
00141     ":MovementTable",
00142     ":TokenGroupItems",
00143     ":NoTokenActionSlots",
00144     ":Positions",
00145     ":WrapAround",
00146     ":MultipleSelection",
00147     ":OrigBoxSize",
00148     ":OrigPosition",
00149     ":OrigPaletteRef",
00150     ":Tiling",
00151     ":OrigTransparency",
00152     ":BBBox",
00153     ":OrigLineWidth",
00154     ":OrigLineStyle",
00155     ":OrigRefLineColour",
00156     ":OrigRefFillColour",
00157     ":OrigFont",
00158     ":HJustification",
00159     ":VJustification",
00160     ":LineOrientation",
00161     ":StartCorner",
00162     ":TextWrapping",
00163     ":Multiplex",
00164     ":Storage",
00165     ":Looping",
00166     ":Audio",
00167     ":Video",
00168     ":RTGraphics",
00169     ":ComponentTag",
00170     ":OrigVolume",
00171     ":Termination",
00172     ":EngineResp",
00173     ":Orientation",
00174     ":MaxValue",
00175     ":MinValue",
00176     ":InitialValue",
00177     ":InitialPortion",
00178     ":StepSize",
00179     ":SliderStyle",
00180     ":InputType",
00181     ":CharList",
00182     ":ObscuredInput",
00183     ":MaxLength",
00184     ":OrigLabel",
00185     ":ButtonStyle",
00186     ":Activate",
00187     ":Add",
00188     ":AddItem",
00189     ":Append",
00190     ":BringToFront",
00191     ":Call",
00192     ":CallActionSlot",
00193     ":Clear",
00194     ":Clone",
00195     ":CloseConnection",
00196     ":Deactivate",
00197     ":DelItem",
00198     ":Deselect",
00199     ":DeselectItem",
00200     ":Divide",
00201     ":DrawArc",
00202     ":DrawLine",
00203     ":DrawOval",
00204     ":DrawPolygon",
00205     ":DrawPolyline",
00206     ":DrawRectangle",
00207     ":DrawSector",
00208     ":Fork",
00209     ":GetAvailabilityStatus",
00210     ":GetBoxSize",
00211     ":GetCellItem",
00212     ":GetCursorPosition",
00213     ":GetEngineSupport",
00214     ":GetEntryPoint",
00215     ":GetFillColour",
00216     ":GetFirstItem",
00217     ":GetHighlightStatus",
00218     ":GetInteractionStatus",
00219     ":GetItemStatus",
00220     ":GetLabel",
00221     ":GetLastAnchorFired",
00222     ":GetLineColour",
00223     ":GetLineStyle",
00224     ":GetLineWidth",
00225     ":GetListItem",
00226     ":GetListSize",
00227     ":GetOverwriteMode",
00228     ":GetPortion",
00229     ":GetPosition",
00230     ":GetRunningStatus",
00231     ":GetSelectionStatus",
00232     ":GetSliderValue",
00233     ":GetTextContent",
00234     ":GetTextData",
00235     ":GetTokenPosition",
00236     ":GetVolume",
00237     ":Launch",
00238     ":LockScreen",
00239     ":Modulo",
00240     ":Move",
00241     ":MoveTo",
00242     ":Multiply",
00243     ":OpenConnection",
00244     ":Preload",
00245     ":PutBefore",
00246     ":PutBehind",
00247     ":Quit",
00248     ":ReadPersistent",
00249     ":Run",
00250     ":ScaleBitmap",
00251     ":ScaleVideo",
00252     ":ScrollItems",
00253     ":Select",
00254     ":SelectItem",
00255     ":SendEvent",
00256     ":SendToBack",
00257     ":SetBoxSize",
00258     ":SetCachePriority",
00259     ":SetCounterEndPosition",
00260     ":SetCounterPosition",
00261     ":SetCounterTrigger",
00262     ":SetCursorPosition",
00263     ":SetCursorShape",
00264     ":SetData",
00265     ":SetEntryPoint",
00266     ":SetFillColour",
00267     ":SetFirstItem",
00268     ":SetFontRef",
00269     ":SetHighlightStatus",
00270     ":SetInteractionStatus",
00271     ":SetLabel",
00272     ":SetLineColour",
00273     ":SetLineStyle",
00274     ":SetLineWidth",
00275     ":SetOverwriteMode",
00276     ":SetPaletteRef",
00277     ":SetPortion",
00278     ":SetPosition",
00279     ":SetSliderValue",
00280     ":SetSpeed",
00281     ":SetTimer",
00282     ":SetTransparency",
00283     ":SetVariable",
00284     ":SetVolume",
00285     ":Spawn",
00286     ":Step",
00287     ":Stop",
00288     ":StorePersistent",
00289     ":Subtract",
00290     ":TestVariable",
00291     ":Toggle",
00292     ":ToggleItem",
00293     ":TransitionTo",
00294     ":Unload",
00295     ":UnlockScreen",
00296     ":GBoolean",
00297     ":GInteger",
00298     ":GOctetString",
00299     ":GObjectRef",
00300     ":GContentRef",
00301     ":NewColourIndex",
00302     ":NewAbsoluteColour",
00303     ":NewFontName",
00304     ":NewFontRef",
00305     ":NewContentSize",
00306     ":NewCCPriority",
00307     ":IndirectRef",
00308 /* UK MHEG */
00309     ":SetBackgroundColour",
00310     ":SetCellPosition",
00311     ":SetInputRegister",
00312     ":SetTextColour",
00313     ":SetFontAttributes",
00314     ":SetVideoDecodeOffset",
00315     ":GetVideoDecodeOffset",
00316     ":GetFocusPosition",
00317     ":SetFocusPosition",
00318     ":SetBitmapDecodeOffset",
00319     ":GetBitmapDecodeOffset",
00320     ":SetSliderParameters",
00321 /* Pseudo-operations.  These are encoded as LinkCondition in binary. */
00322     ":EventSource",
00323     ":EventType",
00324     ":EventData",
00325     ":ActionSlots"
00326 };
00327 
00328 // Some example programs use these colour names
00329 static struct { const char *name; unsigned char r, g, b, t; } colourTable[] =
00330 {
00331     { "black",          0,  0,  0,  0   },
00332     { "transparent",    0,  0,  0,  255 },
00333     { "gray"/*sic*/,    128,128,128,0 },
00334     { "darkgray"/*sic*/,192,192,192,0 },
00335     { "red",            255,0,  0,  0 },
00336     { "darkred",        128,0,  0,  0 },
00337     { "blue",           0,  0,  255,0 },
00338     { "darkblue",       0,  0,  128,0 },
00339     { "green",          0,  255,0,  0 },
00340     { "darkgreen",      0,  128,0,  0 },
00341     { "yellow",         255,255,0,  0 },
00342     { "cyan",           0,  255,255,0 },
00343     { "magenta",        255,0,  255,0 }
00344 };
00345 
00346 
00347 // Search for a tag and return it if it exists.  Returns -1 if it isn't found.
00348 int FindTag(const char *p)
00349 {
00350     for (int i = 0; i < (int)(sizeof(rchTagNames)/sizeof(rchTagNames[0])); i++) {
00351         if (stricmp(p, rchTagNames[i]) == 0) return i;
00352     }
00353     return -1;
00354 }
00355 
00356 
00357 // Ditto for the enumerated types
00358 #define MAX_ENUM        30
00359 
00360 void MHParseText::Error(const char *str)
00361 {
00362     MHERROR(QString("%1- at line %2\n").arg(str).arg(m_lineCount));
00363 }
00364 
00365 // Lexical analysis.  Get the next symbol.
00366 void MHParseText::NextSym()
00367 {
00368     while (1) {
00369 
00370         switch (m_ch) {
00371         case '\n': m_lineCount++; // And drop to next
00372         case ' ': case '\r': case '\t': case '\f':
00373             // Skip white space.
00374             GetNextChar();
00375             continue;
00376 
00377         case '/':
00378             { // Comment.
00379                 GetNextChar();
00380                 if (m_ch != '/') Error("Malformed comment");
00381                 do { GetNextChar(); } while (m_ch != '\n' && m_ch != '\f' && m_ch != '\r');
00382                 continue; // Next symbol
00383             }
00384 
00385         case ':': // Start of a tag
00386             {
00387                 m_nType = PTTag;
00388                 char buff[MAX_TAG_LENGTH+1];
00389                 char *p = buff;
00390                 do {
00391                     *p++ = m_ch;
00392                     GetNextChar();
00393                     if (p == buff + MAX_TAG_LENGTH) break;
00394                 } while ((m_ch >= 'a' && m_ch <= 'z') || (m_ch >= 'A' && m_ch <= 'Z'));
00395                 *p = 0;
00396 
00397                 // Look it up and return it if it's found.
00398                 m_nTag = FindTag(buff);
00399                 if (m_nTag >= 0) return;
00400                 // Unrecognised tag.
00401                 Error("Unrecognised tag");
00402             }
00403 
00404         case '"': // Start of a string
00405             {
00406                 m_nType = PTString;
00407                 // MHEG strings can include NULLs.  For the moment we pass back the length and also
00408                 // null-terminate the strings.
00409                 m_nStringLength = 0;
00410                 while (1) {
00411                     GetNextChar();
00412                     if (m_ch == '"') break; // Finished the string.
00413                     if (m_ch == '\\') GetNextChar(); // Escape character. Include the next char in the string.
00414                     if (m_ch == '\n' || m_ch == '\r') Error("Unterminated string");
00415                     // We grow the buffer to the largest string in the input.
00416                     unsigned char *str = (unsigned char*)realloc(m_String, m_nStringLength+2);
00417                     if (str == NULL) Error("Insufficient memory");
00418                     m_String = str;
00419                     m_String[m_nStringLength++] = m_ch;
00420                 }
00421                 GetNextChar(); // Skip the closing quote
00422                 m_String[m_nStringLength] = 0;
00423                 return;
00424             }
00425 
00426         case '\'': // Start of a string using quoted printable
00427             {
00428                 m_nType = PTString;
00429                 m_nStringLength = 0;
00430                 // Quotable printable strings contain escape sequences beginning with the
00431                 // escape character '='.  The strings can span lines but each line must
00432                 // end with an equal sign.
00433                 while (1) {
00434                     GetNextChar();
00435                     if (m_ch == '\'') break;
00436                     if (m_ch == '\n') Error("Unterminated string");
00437                     if (m_ch == '=') { // Special code in quoted-printable.
00438                         // Should be followed by two hex digits or by white space and a newline.
00439                         GetNextChar();
00440                         if (m_ch == ' ' || m_ch == '\t' || m_ch == '\r' || m_ch == '\n') {
00441                             // White space.  Remove everything up to the newline.
00442                             while (m_ch != '\n') {
00443                                 if (! (m_ch == ' ' || m_ch == '\t' || m_ch == '\r')) {
00444                                     Error("Malformed quoted printable string");
00445                                 }
00446                                 GetNextChar();
00447                             }
00448                             continue; // continue with the first character on the next line
00449                         }
00450                         else {
00451                             int byte = 0;
00452                             if (m_ch >= '0' && m_ch <= '9') byte = m_ch - '0';
00453                             else if (m_ch >= 'A' && m_ch <= 'F') byte = m_ch - 'A' + 10;
00454                             else if (m_ch >= 'a' && m_ch <= 'f') byte = m_ch - 'a' + 10;
00455                             else Error("Malformed quoted printable string");
00456                             byte *= 16;
00457                             GetNextChar();
00458                             if (m_ch >= '0' && m_ch <= '9') byte += m_ch - '0';
00459                             else if (m_ch >= 'A' && m_ch <= 'F') byte += m_ch - 'A' + 10;
00460                             else if (m_ch >= 'a' && m_ch <= 'f') byte += m_ch - 'a' + 10;
00461                             else Error("Malformed quoted printable string");
00462                             m_ch = byte; // Put this into the string.
00463                         }
00464                     }
00465                     // We grow the buffer to the largest string in the input.
00466                     unsigned char *str = (unsigned char*)realloc(m_String, m_nStringLength+2);
00467                     if (str == NULL) Error("Insufficient memory");
00468                     m_String = str;
00469                     m_String[m_nStringLength++] = m_ch;
00470                 }
00471                 GetNextChar(); // Skip the closing quote
00472                 m_String[m_nStringLength] = 0;
00473                 return;
00474             }
00475 
00476         case '`': // Start of a string using base 64
00477             // These can, presumably span lines.
00478             MHERROR("Base 64 string is not implemented");
00479             break;
00480 
00481         case '#': // Start of 3-byte hex constant.
00482             MHERROR("3-byte hex constant is not implemented");
00483             break;
00484 
00485         case '-': case '0': case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9':
00486             {
00487                 m_nType = PTInt;
00488                 bool negative = m_ch == '-';
00489                 if (negative) {
00490                     GetNextChar();
00491                     if (m_ch < '0' || m_ch > '9') Error("Expected digit after '-'");
00492                 }
00493                 // Start of a number.  Hex can be represented as 0xn.
00494                 // Strictly speaking hex values cannot be preceded by a minus sign.
00495                 m_nInt = m_ch - '0';
00496                 GetNextChar();
00497                 if (m_nInt == 0 && (m_ch == 'x' || m_ch == 'X')) {
00498                     MHERROR("Hex constant is not implemented");
00499                 }
00500                 while (m_ch >= '0' && m_ch <= '9') {
00501                     m_nInt = m_nInt * 10 + m_ch - '0';
00502                     // TODO: What about overflow?
00503                     GetNextChar();
00504                 }
00505                 if (negative) m_nInt = -m_nInt;
00506                 return;
00507             }
00508 
00509         case 'a': case 'b': case 'c': case 'd': case 'e': case 'f': case 'g': case 'h': case 'i': case 'j':
00510         case 'k': case 'l': case 'm': case 'n': case 'o': case 'p': case 'q': case 'r': case 's': case 't':
00511         case 'u': case 'v': case 'w': case 'x': case 'y': case 'z': 
00512         case 'A': case 'B': case 'C': case 'D': case 'E': case 'F': case 'G': case 'H': case 'I': case 'J':
00513         case 'K': case 'L': case 'M': case 'N': case 'O': case 'P': case 'Q': case 'R': case 'S': case 'T':
00514         case 'U': case 'V': case 'W': case 'X': case 'Y': case 'Z':
00515             { // Start of an enumerated type.
00516                 m_nType = PTEnum;
00517                 char buff[MAX_ENUM+1];
00518                 char *p = buff;
00519                 do {
00520                     *p++ = m_ch;
00521                     GetNextChar();
00522                     if (p == buff+MAX_ENUM) break;
00523                 }
00524                 while ((m_ch >= 'a' && m_ch <= 'z') || (m_ch >= 'A' && m_ch <= 'Z') || m_ch == '-');
00525                 *p = '\0';
00526                 if (stricmp(buff, "NULL") == 0) { m_nType = PTNull; return; }
00527                 if (stricmp(buff, "true") == 0) { m_nType = PTBool; m_fBool = true; return; }
00528                 if (stricmp(buff, "false") == 0) { m_nType = PTBool; m_fBool = false; return; }
00529                 // Look up the tag in all the tables.  Fortunately all the enumerations
00530                 // are distinct so we don't need to know the context.
00531                 m_nInt = MHLink::GetEventType(buff);
00532                 if (m_nInt > 0) return;
00533                 m_nInt = MHText::GetJustification(buff);
00534                 if (m_nInt > 0) return;
00535                 m_nInt = MHText::GetLineOrientation(buff);
00536                 if (m_nInt > 0) return;
00537                 m_nInt = MHText::GetStartCorner(buff);
00538                 if (m_nInt > 0) return;
00539                 m_nInt = MHSlider::GetOrientation(buff);
00540                 if (m_nInt > 0) return;
00541                 m_nInt = MHSlider::GetStyle(buff);
00542                 if (m_nInt > 0) return;
00543 
00544                 // Check the colour table.  If it's there generate a string containing the colour info.
00545                 for (int i = 0; i < (int)(sizeof(colourTable)/sizeof(colourTable[0])); i++) {
00546                     if (stricmp(buff, colourTable[i].name) == 0) {
00547                         m_nType = PTString;
00548                         unsigned char *str = (unsigned char*)realloc(m_String, 4+1);
00549                         if (str == NULL) Error("Insufficient memory");
00550                         m_String[0] = colourTable[i].r;
00551                         m_String[1] = colourTable[i].g;
00552                         m_String[2] = colourTable[i].b;
00553                         m_String[3] = colourTable[i].t;
00554                         m_String = str;
00555                         m_nStringLength = 4;
00556                         return;
00557                     }
00558                 }
00559 
00560                 Error("Unrecognised enumeration");
00561                 break;
00562             }
00563 
00564         case '{': // Start of a "section".
00565             // The standard indicates that open brace followed by a tag should be written
00566             // as a single word.  We'll be more lenient and allow spaces or comments between them.
00567             m_nType = PTStartSection;
00568             GetNextChar();
00569             return;
00570 
00571         case '}': // End of a "section".
00572             m_nType = PTEndSection;
00573             GetNextChar();
00574             return;
00575 
00576         case '(': // Start of a sequence.
00577             m_nType = PTStartSeq;
00578             GetNextChar();
00579             return;
00580 
00581         case ')': // End of a sequence.
00582             m_nType = PTEndSeq;
00583             GetNextChar();
00584             return;
00585 
00586         case EOF:
00587             m_nType = PTEOF;
00588             return;
00589 
00590         default:
00591             Error("Unknown character");
00592             GetNextChar();
00593         }
00594     }
00595 }
00596 
00597 MHParseNode *MHParseText::DoParse()
00598 {
00599     MHParseNode *pRes = NULL;
00600     try {
00601         switch (m_nType) {
00602         case PTStartSection: // Open curly bracket
00603             {
00604                 NextSym();
00605                 // Should be followed by a tag.
00606                 if (m_nType != PTTag) Error("Expected ':' after '{'");
00607                 MHPTagged *pTag = new MHPTagged(m_nTag);
00608                 pRes = pTag;
00609                 NextSym();
00610                 while (m_nType != PTEndSection) {
00611                     pTag->AddArg(DoParse());
00612                 }
00613                 NextSym(); // Remove the close curly bracket.
00614                 break;
00615             }
00616 
00617         case PTTag: // Tag on its own.
00618             {
00619                 int nTag = m_nTag;
00620                 MHPTagged *pTag = new MHPTagged(nTag);
00621                 pRes = pTag;
00622                 NextSym();
00623                 switch (nTag) {
00624                 case C_ITEMS:
00625                 case C_LINK_EFFECT:
00626                 case C_ACTIVATE:
00627                 case C_ADD:
00628                 case C_ADD_ITEM:
00629                 case C_APPEND:
00630                 case C_BRING_TO_FRONT:
00631                 case C_CALL:
00632                 case C_CALL_ACTION_SLOT:
00633                 case C_CLEAR:
00634                 case C_CLONE:
00635                 case C_CLOSE_CONNECTION:
00636                 case C_DEACTIVATE:
00637                 case C_DEL_ITEM:
00638                 case C_DESELECT:
00639                 case C_DESELECT_ITEM:
00640                 case C_DIVIDE:
00641                 case C_DRAW_ARC:
00642                 case C_DRAW_LINE:
00643                 case C_DRAW_OVAL:
00644                 case C_DRAW_POLYGON:
00645                 case C_DRAW_POLYLINE:
00646                 case C_DRAW_RECTANGLE:
00647                 case C_DRAW_SECTOR:
00648                 case C_FORK:
00649                 case C_GET_AVAILABILITY_STATUS:
00650                 case C_GET_BOX_SIZE:
00651                 case C_GET_CELL_ITEM:
00652                 case C_GET_CURSOR_POSITION:
00653                 case C_GET_ENGINE_SUPPORT:
00654                 case C_GET_ENTRY_POINT:
00655                 case C_GET_FILL_COLOUR:
00656                 case C_GET_FIRST_ITEM:
00657                 case C_GET_HIGHLIGHT_STATUS:
00658                 case C_GET_INTERACTION_STATUS:
00659                 case C_GET_ITEM_STATUS:
00660                 case C_GET_LABEL:
00661                 case C_GET_LAST_ANCHOR_FIRED:
00662                 case C_GET_LINE_COLOUR:
00663                 case C_GET_LINE_STYLE:
00664                 case C_GET_LINE_WIDTH:
00665                 case C_GET_LIST_ITEM:
00666                 case C_GET_LIST_SIZE:
00667                 case C_GET_OVERWRITE_MODE:
00668                 case C_GET_PORTION:
00669                 case C_GET_POSITION:
00670                 case C_GET_RUNNING_STATUS:
00671                 case C_GET_SELECTION_STATUS:
00672                 case C_GET_SLIDER_VALUE:
00673                 case C_GET_TEXT_CONTENT:
00674                 case C_GET_TEXT_DATA:
00675                 case C_GET_TOKEN_POSITION:
00676                 case C_GET_VOLUME:
00677                 case C_LAUNCH:
00678                 case C_LOCK_SCREEN:
00679                 case C_MODULO:
00680                 case C_MOVE:
00681                 case C_MOVE_TO:
00682                 case C_MULTIPLY:
00683                 case C_OPEN_CONNECTION:
00684                 case C_PRELOAD:
00685                 case C_PUT_BEFORE:
00686                 case C_PUT_BEHIND:
00687                 case C_QUIT:
00688                 case C_READ_PERSISTENT:
00689                 case C_RUN:
00690                 case C_SCALE_BITMAP:
00691                 case C_SCALE_VIDEO:
00692                 case C_SCROLL_ITEMS:
00693                 case C_SELECT:
00694                 case C_SELECT_ITEM:
00695                 case C_SEND_EVENT:
00696                 case C_SEND_TO_BACK:
00697                 case C_SET_BOX_SIZE:
00698                 case C_SET_CACHE_PRIORITY:
00699                 case C_SET_COUNTER_END_POSITION:
00700                 case C_SET_COUNTER_POSITION:
00701                 case C_SET_COUNTER_TRIGGER:
00702                 case C_SET_CURSOR_POSITION:
00703                 case C_SET_CURSOR_SHAPE:
00704                 case C_SET_DATA:
00705                 case C_SET_ENTRY_POINT:
00706                 case C_SET_FILL_COLOUR:
00707                 case C_SET_FIRST_ITEM:
00708                 case C_SET_FONT_REF:
00709                 case C_SET_HIGHLIGHT_STATUS:
00710                 case C_SET_INTERACTION_STATUS:
00711                 case C_SET_LABEL:
00712                 case C_SET_LINE_COLOUR:
00713                 case C_SET_LINE_STYLE:
00714                 case C_SET_LINE_WIDTH:
00715                 case C_SET_OVERWRITE_MODE:
00716                 case C_SET_PALETTE_REF:
00717                 case C_SET_PORTION:
00718                 case C_SET_POSITION:
00719                 case C_SET_SLIDER_VALUE:
00720                 case C_SET_SPEED:
00721                 case C_SET_TIMER:
00722                 case C_SET_TRANSPARENCY:
00723                 case C_SET_VARIABLE:
00724                 case C_SET_VOLUME:
00725                 case C_SPAWN:
00726                 case C_STEP:
00727                 case C_STOP:
00728                 case C_STORE_PERSISTENT:
00729                 case C_SUBTRACT:
00730                 case C_TEST_VARIABLE:
00731                 case C_TOGGLE:
00732                 case C_TOGGLE_ITEM:
00733                 case C_TRANSITION_TO:
00734                 case C_UNLOAD:
00735                 case C_UNLOCK_SCREEN:
00736                 case C_CONTENT_REFERENCE:
00737                 case C_TOKEN_GROUP_ITEMS:
00738                 case C_POSITIONS:
00739                 case C_MULTIPLEX:
00740                     {   // These are parenthesised in the text form.  We have to remove the
00741                         // parentheses otherwise we will return a sequence which will not be
00742                         // be compatible with the binary form.
00743                         if (m_nType != PTStartSeq) Error("Expected '('");
00744                         NextSym();
00745                         while (m_nType != PTEndSeq) pTag->AddArg(DoParse());
00746                         NextSym(); // Remove the close parenthesis.
00747                         break;
00748                     }
00749                 case C_ORIGINAL_CONTENT:
00750                 case C_NEW_GENERIC_BOOLEAN:
00751                 case C_NEW_GENERIC_INTEGER:
00752                 case C_NEW_GENERIC_OCTETSTRING:
00753                 case C_NEW_GENERIC_OBJECT_REF:
00754                 case C_NEW_GENERIC_CONTENT_REF:
00755                 case C_ORIGINAL_VALUE:
00756                     // These always have an argument which may be a tagged item.
00757                     {
00758                         // Is it always the case that there is at least one argument so if we haven't
00759                         // had any arguments yet we should always process a tag as an argument?
00760                         pTag->AddArg(DoParse());
00761                         break;
00762                     }
00763                 default:
00764                     // This can be followed by an int, etc but a new tag is dealt with by the caller.
00765                     while (m_nType == PTBool ||m_nType == PTInt || m_nType == PTString || m_nType == PTEnum || m_nType == PTStartSeq) {
00766                         pTag->AddArg(DoParse());
00767                     }
00768 
00769                 }
00770                 break;
00771             }
00772 
00773         case PTInt:
00774             {
00775                 pRes = new MHPInt(m_nInt);
00776                 NextSym();
00777                 break;
00778             }
00779 
00780         case PTBool:
00781             {
00782                 pRes = new MHPBool(m_fBool);
00783                 NextSym();
00784                 break;
00785             }
00786 
00787         case PTString:
00788             {
00789                 MHOctetString str;
00790                 str.Copy(MHOctetString((const char *)m_String, m_nStringLength));
00791                 pRes = new MHPString(str);
00792                 NextSym();
00793                 break;
00794             }
00795 
00796         case PTEnum:
00797             {
00798                 pRes = new MHPEnum(m_nInt);
00799                 NextSym();
00800                 break;
00801             }
00802 
00803         case PTNull:
00804             {
00805                 pRes = new MHPNull;
00806                 NextSym();
00807                 break;
00808             }
00809 
00810         case PTStartSeq: // Open parenthesis.
00811             {
00812                 MHParseSequence *pSeq = new MHParseSequence;
00813                 pRes = pSeq;
00814                 NextSym();
00815                 while (m_nType != PTEndSeq) pSeq->Append(DoParse());
00816                 NextSym(); // Remove the close parenthesis.
00817                 break;
00818             }
00819 
00820         default:
00821             Error("Unexpected symbol");
00822         }
00823         return pRes;
00824     }
00825     catch (...) {
00826         delete(pRes);
00827         throw;
00828     }
00829 }
00830 
00831 
00832 // Run the parser
00833 MHParseNode *MHParseText::Parse()
00834 {
00835     GetNextChar(); // Initialise m_ch
00836     NextSym(); // Initialise the symbol values.
00837     return DoParse();
00838 }
00839