Castle Game Engine: CastleClassUtils

# Unit CastleClassUtils
Description | Uses | Classes, Interfaces, Objects and Records | Functions and Procedures | Types | Constants | Variables
## Description Basic classes and class utilities (for streams, strings, lists and such). Many utilities for classes that are defined in the Classes unit, and some classes of our my own. Some notes about TStream descendants : I call a stream "purely sequential" (or just "sequential") if it allows only reading and/or writing of data and does not allow free "Seek" calls, in particular — it does not allow Seek to move back in a stream. I call a stream "growing" if it's read-only and it's purely sequential and it's Size property may be useless. In other words, when you read a "growing" stream, you don't know when it ends, until you reach the end. You just have to read data until Read returns 0. Remember that to reliably detect end of the stream when you use TStream.Read, you have to test is ReadCount = 0. Merely testing that ReadCount < less than you requested is not enough, e.g. seen for THandleStream when handle is StdIn. ## Uses Classes SysUtils CastleUtils CastleStringUtils Contnrs FGL CastleGenericLists CastleVectors ## Overview ### Classes, Interfaces, Objects and Records
Name | Description
--- | ---
Class `TTextReaderWriter` | Common class for reading or writing a stream like a text file.
Class `TTextReader` | Read any TStream like a text file.
Class `TTextWriter` | Write to a stream like to a text file.
Class `TStringListCaseSens` | TStringList that is case sensitive.
Class `EStreamNotImplemented` |
Class `EStreamNotImplementedWrite` |
Class `EStreamNotImplementedSeek` |
Class `EStreamNotImplementedSetSize` |
Class `TPeekCharStream` | Abstract class to read another stream, always being able to back one character.
Class `TSimplePeekCharStream` | Read another stream, sequentially, always being able to back one character.
Class `TBufferedReadStream` | Read another stream, sequentially, always being able to back one character, and buffering it.
Class `TCastleObjectStack` |
Class `TCastleObjectQueue` |
Class `TCastleObjectList` | Extended TObjectList for Castle Game Engine.
Class `TNotifyEventList` |
### Functions and Procedures
`procedure StringsAdd(Strs: TStrings; Count: integer; itemVal: string='dummy'); overload;`
`procedure AddStrArrayToStrings(const StrArr: array of string; strlist: TStrings);`
`procedure Strings_AddSplittedString(Strings: TStrings; const S, Splitter: string);`
`procedure Strings_AddCastleEngineProgramHelpSuffix( Strings: TStrings; const DisplayApplicationName: string; const Version: string; WrapLines: boolean);`
`procedure Strings_SetText(SList: TStrings; const S: string);`
`procedure Strings_Trim(Strings: TStrings; MaxCount: Cardinal);`
`procedure StreamWriteLongWord(Stream: TStream; const Value: LongWord);`
`function StreamReadLongWord(Stream: TStream): LongWord;`
`procedure StreamWriteByte(Stream: TStream; const Value: Byte);`
`function StreamReadByte(Stream: TStream): Byte;`
`procedure WriteStr(Stream: TStream; const S: string); overload;`
`procedure WritelnStr(Stream: TStream; const S: string); overload;`
`procedure WriteStr(const S: string); overload;`
`procedure WritelnStr(const S: string); overload;`
`function StreamReadChar(Stream: TStream): char;`
`function StreamReadZeroEndString(Stream: TStream): string;`
`function StreamReadUpto_NotEOS(Stream: TStream; const endingChars: TSetOfChars; backEndingChar: boolean; out endingChar: char): string; overload;`
`function StreamReadUpto_NotEOS(Stream: TStream; const endingChars: TSetOfChars; backEndingChar: boolean): string; overload;`
`function StreamReadUpto_NotEOS(Stream: TStream; const endingChars: TSetOfChars; out endingChar: char): string; overload;`
`function StreamReadUpto_NotEOS(Stream: TStream; const endingChars: TSetOfChars): string; overload;`
`function StreamReadUpto_EOS(Stream: TStream; const endingChars: TSetOfChars; backEndingChar: boolean; out endingChar: integer): string; overload;`
`function StreamReadUpto_EOS(Stream: TStream; const endingChars: TSetOfChars; backEndingChar: boolean): string; overload;`
`function StreamReadUpto_EOS(Stream: TStream; const endingChars: TSetOfChars; out endingChar: integer): string; overload;`
`function StreamReadUpto_EOS(Stream: TStream; const endingChars: TSetOfChars): string; overload;`
`function CreateReadFileStream(const URL: string): TStream; deprecated;`
`procedure ReadGrowingStream(GrowingStream, DestStream: TStream; ResetDestStreamPosition: boolean);`
`function ReadGrowingStreamToString(GrowingStream: TStream): string;`
`procedure StreamWriteString(Stream: TStream; const s: string);`
`function StreamReadString(Stream: TStream): string;`
`function StreamToString(Stream: TStream): string;`
`procedure StreamSaveToFile(Stream: TStream; const URL: string);`
`procedure MemoryStreamLoadFromString(const Stream: TMemoryStream; const S: string; const Rewind: boolean = true);`
`function MemoryStreamLoadFromString( const S: string; const Rewind: boolean = true): TMemoryStream;`
`procedure CreateIfNeeded(var Component: TComponent; ComponentClass: TComponentClass; Owner: TComponent);`
`function FPGObjectList_RemoveNils(List: TFPSList): Cardinal;`
`procedure FPGObjectList_ReplaceAll(List: TFPSList; OldItem, NewItem: TObject);`
`procedure FPGObjectList_FreeAndNilItem(List: TFPSList; I: Integer);`
`procedure FPGObjectList_NilItem(List: TFPSList; I: Integer);`
### Constants
`DefaultReadBufferSize = 1024 * 1024;`
### Variables
`StdInStream:TStream;`
`StdOutStream:TStream;`
`StdErrStream:TStream;`
`StdInReader: TTextReader;`
## Description ### Functions and Procedures
`procedure StringsAdd(Strs: TStrings; Count: integer; itemVal: string='dummy'); overload;`
Add some strings.
`procedure AddStrArrayToStrings(const StrArr: array of string; strlist: TStrings);`
Add all strings from string array to TStrings instance.
`procedure Strings_AddSplittedString(Strings: TStrings; const S, Splitter: string);`
Splits S by Splitter, and adds each splitted part to Strings. Splitting is done by Splitter, i.e. if N is the number of occurrences of Splitter inside S, then it always adds N + 1 strings to Strings. Yes, this means that if S starts with Splitter then the first part is equal to ''. And if S ends with Splitter then the last oart is equal to ''.
`procedure Strings_AddCastleEngineProgramHelpSuffix( Strings: TStrings; const DisplayApplicationName: string; const Version: string; WrapLines: boolean);`
Something like SCastleEngineProgramHelpSuffix, but appends contents as a couple of lines to Strings.
`procedure Strings_SetText(SList: TStrings; const S: string);`
Use this instead of `SList.Text := S` to workaround FPC 2.0.2 bug. See [http://www.freepascal.org/mantis/view.php?id=6699]
`procedure Strings_Trim(Strings: TStrings; MaxCount: Cardinal);`
Make sure we don't have more than MaxCount strings on a list. Removes the last strings if necessary.
`procedure StreamWriteLongWord(Stream: TStream; const Value: LongWord);`
`function StreamReadLongWord(Stream: TStream): LongWord;`
`procedure StreamWriteByte(Stream: TStream; const Value: Byte);`
`function StreamReadByte(Stream: TStream): Byte;`
`procedure WriteStr(Stream: TStream; const S: string); overload;`
Write string contents to stream. This isn't a procedure to encode a string within a binary stream, this only writes string contents (Length(S) bytes) into the stream. Versions with "ln" append newline. Versions without Stream parameter write to StdOutStream.
`procedure WritelnStr(Stream: TStream; const S: string); overload;`
`procedure WriteStr(const S: string); overload;`
`procedure WritelnStr(const S: string); overload;`
`function StreamReadChar(Stream: TStream): char;`
Read one character from stream. ###### Exceptions raised `EReadError` If end of stream.
`function StreamReadZeroEndString(Stream: TStream): string;`
`function StreamReadUpto_NotEOS(Stream: TStream; const endingChars: TSetOfChars; backEndingChar: boolean; out endingChar: char): string; overload;`
Read stream, until you find some character in EndingChars. Returns read contents, without final character (the one in EndingChars set). If you use a version with BackEndingChar parameter and pass BackEndingChar = `True`, then the ending character will be returned back to stream (we will start reading from it next time). Note that "returning the character" is done by Seek(-1, soFromCurrent), which may not be possible on some streams. Wrap a stream in TPeekCharStream instead, and use TPeekCharStream.ReadUpto, to be able to "return back" a character reliably. Independently from BackEndingChar, if you use a version with EndingChar parameter, it will be set to the ending character. ###### Exceptions raised `EReadError` If the stream will end before encountering one of EndingChars.
`function StreamReadUpto_NotEOS(Stream: TStream; const endingChars: TSetOfChars; backEndingChar: boolean): string; overload;`
`function StreamReadUpto_NotEOS(Stream: TStream; const endingChars: TSetOfChars; out endingChar: char): string; overload;`
`function StreamReadUpto_NotEOS(Stream: TStream; const endingChars: TSetOfChars): string; overload;`
`function StreamReadUpto_EOS(Stream: TStream; const endingChars: TSetOfChars; backEndingChar: boolean; out endingChar: integer): string; overload;`
Read stream, until you find some character in EndingChars, or end of stream. Compared to StreamReadUpto_NotEOS, this treats "end of stream" as a normal situation, and doesn't raise any exception on it. It sets EndingChar to -1 on end of stream. When EndingChar is not -1, you know you can safely cast it to normal 8-bit character. Everything else works like with StreamReadUpto_NotEOS.
`function StreamReadUpto_EOS(Stream: TStream; const endingChars: TSetOfChars; backEndingChar: boolean): string; overload;`
`function StreamReadUpto_EOS(Stream: TStream; const endingChars: TSetOfChars; out endingChar: integer): string; overload;`
`function StreamReadUpto_EOS(Stream: TStream; const endingChars: TSetOfChars): string; overload;`
`function CreateReadFileStream(const URL: string): TStream; deprecated;`
Warning: this symbol is deprecated. Open a proper stream to read a file, fast (with buffering) and with seeking. This gives you a stream most comfortable for reading (buffering means that you can read small, comfortable pieces of it; seeking means you can jump freely to various file positions, back and forward). On different OSes or even compilers this may require a little different stream, so it's safest to just use this function. For example, traditional Classes.TFileStream doesn't do buffering. Although under Linux, the buffering of file handles is done at kernel level (so everything works fast), on Windows the slowdown is noticeable. This function will always create proper stream descendant, eventually wrapping some standard stream in a buffered stream with full seeking capability. Instead of this, use CastleDownload.Download with LocalFileInMemory.
`procedure ReadGrowingStream(GrowingStream, DestStream: TStream; ResetDestStreamPosition: boolean);`
Read a growing stream, and append it to another destination stream. A "growing stream" is a stream that we can only read sequentially, no seeks allowed, and size is unknown until we hit the end. The only operation we do on GrowingStream is GrowingStream.Read and the only operation on DestStream is DestStream.WriteBuffer. So DestStream usually must be able to grow dynamically to accomodate any GrowingStream input size. This procedure ends when GrowingStream ends. If ResetDestStreamPosition then at the end we do DestStream.Position := 0 (since it is usually useful and it would be easy for you to forget about it).
`function ReadGrowingStreamToString(GrowingStream: TStream): string;`
Read a growing stream, and returns it's contents as a string. A "growing stream" is a stream that we can only read sequentially, no seeks allowed, and size is unknown until we hit the end.
`procedure StreamWriteString(Stream: TStream; const s: string);`
Encode / decode a string in a binary stream. Records string length (4 bytes), then the string contents (Length(S) bytes).
`function StreamReadString(Stream: TStream): string;`
`function StreamToString(Stream: TStream): string;`
Convert whole Stream to a string. Changes Stream.Position to 0 and then reads Stream.Size bytes, so be sure that Stream.Size is usable.
`procedure StreamSaveToFile(Stream: TStream; const URL: string);`
`procedure MemoryStreamLoadFromString(const Stream: TMemoryStream; const S: string; const Rewind: boolean = true);`
Set contents of TMemoryStream to given string. If Rewind then the position is reset to the beginning, otherwise it stays at the end.
`function MemoryStreamLoadFromString( const S: string; const Rewind: boolean = true): TMemoryStream;`
`procedure CreateIfNeeded(var Component: TComponent; ComponentClass: TComponentClass; Owner: TComponent);`
Create Component instance, if it's `Nil`. If Component = nil then it will do `Component := ComponentClass.Create(Owner)`.
`function FPGObjectList_RemoveNils(List: TFPSList): Cardinal;`
Remove all nils. Returns how many instances were removed (how much Count was decreased). Do not call this with other TFPSList descendants, only TFPGObjectList specializations.
`procedure FPGObjectList_ReplaceAll(List: TFPSList; OldItem, NewItem: TObject);`
Replace all OldItem instances with NewItem. Do not call this with other TFPSList descendants, only TFPGObjectList specializations.
`procedure FPGObjectList_FreeAndNilItem(List: TFPSList; I: Integer);`
Free and set to `Nil` given item on TFPGObjectList. Usually, simply assigning to it `Nil` value (when list has FreeObjects = `True`) would do the trick. Unfortunately there's bug http://bugs.freepascal.org/view.php?id=19854 .
`procedure FPGObjectList_NilItem(List: TFPSList; I: Integer);`
Set to `Nil` (never freeing) given item on TFPGObjectList.
### Constants
`DefaultReadBufferSize = 1024 * 1024;`
### Variables
`StdInStream:TStream;`
Streams that wrap standard input/output/error of the program. Note that you can't simultaneously read from `StdInStream` and StdInReader (reasons: see comments at TTextReader class, TTextReader has to internally manage the stream underneath). Notes for Windows: Under Windows when program is a GUI program then some (or all) of the variables below may be nil. But they don't have to be nil. User can run a GUI program and explicitly redirect it's standard stream, e.g. `cat something | my_program` for stdin or `my_program > output.txt` for stdout. Actually some shells, like Cygwin's bash, always redirect some streams "under the mask". And then you have some of std* streams available. Actually FPC (and Delphi?) RTL don't provide in such cases valid Input/Output/ErrOutput variables (because IsConsole = false). But my streams below try to obtain standard stream handles under Windows regardless of IsConsole value. So even a GUI program is able to write to stdin/stdout/stderr using these streams. Unfortunately, in a GUI program under Windows you cannot depend on the fact that "StdOutStream <> nil means that stdout is actually available (because user redirected stdout etc.)". Reason? Windows failure, as usual: This is tested on Windows 2000 Prof, with FPC 2.0.0 and 2.1.1 (revision 4317). When no stdout is available, StdOutStream should be nil, because GetStdHandle(STD_OUTPUT_HANDLE) should return 0. However, GetStdHandle(STD_OUTPUT_HANDLE) doesn't return 0... It returns some stupid handle (no, not INVALID_HANDLE_VALUE either) that you can't write into (trying to write returns in ERROR_INVALID_HANDLE WinAPI error). It seems that there is no way for me to check whether GetStdHandle(STD_OUTPUT_HANDLE) returned valid handle (e.g. because the program's stdout was redirected, so stdout is perfectly available) or whether it returned something unusable. So if you write an $apptype GUI program and you want to try to use stdout anyway, you can't just check for StdOutStream <> nil. You should also check the first write to StdOutStream for EWriteError. Note that GetStdHandle(STD_INPUT_HANDLE) and GetStdHandle(STD_ERROR_HANDLE) work correctly, so it should be OK to check `StdInStream` <> nil or StdErrStream <> nil. The only problematic one is GetStdHandle(STD_OUTPUT_HANDLE).
`StdOutStream:TStream;`
Streams that wrap standard input/output/error of the program. Note that you can't simultaneously read from StdInStream and StdInReader (reasons: see comments at TTextReader class, TTextReader has to internally manage the stream underneath). Notes for Windows: Under Windows when program is a GUI program then some (or all) of the variables below may be nil. But they don't have to be nil. User can run a GUI program and explicitly redirect it's standard stream, e.g. `cat something | my_program` for stdin or `my_program > output.txt` for stdout. Actually some shells, like Cygwin's bash, always redirect some streams "under the mask". And then you have some of std* streams available. Actually FPC (and Delphi?) RTL don't provide in such cases valid Input/Output/ErrOutput variables (because IsConsole = false). But my streams below try to obtain standard stream handles under Windows regardless of IsConsole value. So even a GUI program is able to write to stdin/stdout/stderr using these streams. Unfortunately, in a GUI program under Windows you cannot depend on the fact that "`StdOutStream` <> nil means that stdout is actually available (because user redirected stdout etc.)". Reason? Windows failure, as usual: This is tested on Windows 2000 Prof, with FPC 2.0.0 and 2.1.1 (revision 4317). When no stdout is available, `StdOutStream` should be nil, because GetStdHandle(STD_OUTPUT_HANDLE) should return 0. However, GetStdHandle(STD_OUTPUT_HANDLE) doesn't return 0... It returns some stupid handle (no, not INVALID_HANDLE_VALUE either) that you can't write into (trying to write returns in ERROR_INVALID_HANDLE WinAPI error). It seems that there is no way for me to check whether GetStdHandle(STD_OUTPUT_HANDLE) returned valid handle (e.g. because the program's stdout was redirected, so stdout is perfectly available) or whether it returned something unusable. So if you write an $apptype GUI program and you want to try to use stdout anyway, you can't just check for `StdOutStream` <> nil. You should also check the first write to `StdOutStream` for EWriteError. Note that GetStdHandle(STD_INPUT_HANDLE) and GetStdHandle(STD_ERROR_HANDLE) work correctly, so it should be OK to check StdInStream <> nil or StdErrStream <> nil. The only problematic one is GetStdHandle(STD_OUTPUT_HANDLE).
`StdErrStream:TStream;`
Streams that wrap standard input/output/error of the program. Note that you can't simultaneously read from StdInStream and StdInReader (reasons: see comments at TTextReader class, TTextReader has to internally manage the stream underneath). Notes for Windows: Under Windows when program is a GUI program then some (or all) of the variables below may be nil. But they don't have to be nil. User can run a GUI program and explicitly redirect it's standard stream, e.g. `cat something | my_program` for stdin or `my_program > output.txt` for stdout. Actually some shells, like Cygwin's bash, always redirect some streams "under the mask". And then you have some of std* streams available. Actually FPC (and Delphi?) RTL don't provide in such cases valid Input/Output/ErrOutput variables (because IsConsole = false). But my streams below try to obtain standard stream handles under Windows regardless of IsConsole value. So even a GUI program is able to write to stdin/stdout/stderr using these streams. Unfortunately, in a GUI program under Windows you cannot depend on the fact that "StdOutStream <> nil means that stdout is actually available (because user redirected stdout etc.)". Reason? Windows failure, as usual: This is tested on Windows 2000 Prof, with FPC 2.0.0 and 2.1.1 (revision 4317). When no stdout is available, StdOutStream should be nil, because GetStdHandle(STD_OUTPUT_HANDLE) should return 0. However, GetStdHandle(STD_OUTPUT_HANDLE) doesn't return 0... It returns some stupid handle (no, not INVALID_HANDLE_VALUE either) that you can't write into (trying to write returns in ERROR_INVALID_HANDLE WinAPI error). It seems that there is no way for me to check whether GetStdHandle(STD_OUTPUT_HANDLE) returned valid handle (e.g. because the program's stdout was redirected, so stdout is perfectly available) or whether it returned something unusable. So if you write an $apptype GUI program and you want to try to use stdout anyway, you can't just check for StdOutStream <> nil. You should also check the first write to StdOutStream for EWriteError. Note that GetStdHandle(STD_INPUT_HANDLE) and GetStdHandle(STD_ERROR_HANDLE) work correctly, so it should be OK to check StdInStream <> nil or `StdErrStream` <> nil. The only problematic one is GetStdHandle(STD_OUTPUT_HANDLE).
`StdInReader: TTextReader;`
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