Work with the KOMPAS-3D API → Lesson 16 → Control characters

  • Tutorial
We continue the series of articles on working with the CAD API COMPASS-3D. Control characters have already been seen several times in previous lessons of the cycle. Then each time it was said that the output lines should not contain them, since COMPAS processes them in a special way. Now it's time to get to know them better.

Having mastered the work with them, you will understand that creating complex compound strings is a trivial task, in most cases not requiring writing a large amount of code.

In the lesson, we will look at how to use special characters and font characters with control characters, talk about how to create fractions and deviations with their help, and also consider their use in conjunction with paragraphs.



The content of the lesson series “Working with the KOMPAS-3D API”


  1. The basics
  2. Drawing design
  3. Correct connection to KOMPAS
  4. Main inscription
  5. Graphic primitives
  6. Saving a document in various formats
  7. Getting to know the settings
  8. More sophisticated writing methods in the title block
  9. Reading caption cells
  10. Special characters including a string
  11. Simple text labels
  12. Compound strings
  13. Paragraphs
  14. Multiline text
  15. Paragraph-Based Compound Lines
  16. Control characters

Cursory review


The control characters are: @, $, &,;, ~, ^, and #. Unfortunately, the KOMPAS SDK has very little information on how to use them. For more information, see the help of KOMPAS, in the section “9. KOMPAS-3D settings / Storage of system settings / Service files / User menu file / File syntax .



All control characters can be conditionally divided into two groups: main and auxiliary. Auxiliary symbols are used only in conjunction with the main ones and, by themselves, do not describe any component. The table below provides a brief description of the control characters.



Let's consider them in more detail.

Insert special characters


We have already considered special characters (see lessons 4 and 10 ). Then, to insert one special character, a separate instance of the ksTextItemParam interface was used . Using control characters, you can insert as many special characters into the string as you see fit without reusing the ksTextItemParam interface .
The syntax for inserting special characters is:

AA @ YXXXX ~ BB

where
AA is the line before the special character,
Y is the modifier for representing the special character code,
XXXX is the code for the special character to be inserted.
BB- a string located after the special character.

The code for the inserted special character is specified between @ and ~ . Moreover, depending on the value of modifier Y , it can be specified in decimal or hexadecimal notation. Valid modifier Y values are shown in the table below.



Note: as my experiments show, COMPASS normally processes the absence of the ~ character . In this case, special characters are inserted as needed. However, I highly recommend not relying on this behavior and always complete the insert operation with the ~ character .

The following is an example of a program demonstrating the output of special characters.

BSTR str = SysAllocString(OLESTR("До @+51~ После"));
document2D->ksText(100.0,100.0,0.0,0.0,0.0,0,str);
SysFreeString(str);
str = SysAllocString(OLESTR("До @*33~ После"));
document2D->ksText(100.0,90.0,0.0,0.0,0.0,0,str);
SysFreeString(str);

In this example, the same character (α alpha) is displayed twice. The first time its code is specified in decimal, the second time in hexadecimal. The figure below shows the result of the program.



Control characters allow you to display several special characters on the same line. So, in the following example, the first three letters of the Greek alphabet are displayed in one call to the ksText method .

BSTR str = SysAllocString(OLESTR("@+51~ @+52~ @+53~"));
document2D->ksText(100.0,100.0,0.0,0.0,0.0,0,str);
SysFreeString(str);

The figure below shows the result of this program.



Modifier + is the default modifier. Therefore, the above line can be written like this:

“@ 51 ~ @ 52 ~ @ 53 ~”

In this case, the result of the program will remain the same.

If an @ is an invalid character, the line between @ and ~ is displayed as is. The characters @ and ~ are omitted. For example, with the line:

“Before @ T51 ~ After”

The document will

display : Before T51 After

Note: this behavior of KOMPAS is undocumented and may vary in different versions of the program.

Note:control characters are not suitable for inserting special characters containing a string. The fact is that to limit their action you need to use the flag SPECIAL_SYMBOL_END (for more details see 10 lesson of the cycle), but control characters do not allow the use of flags.

Insert font characters


In addition to special characters, you can insert ordinary characters by their code. The control characters ^ and ~ are used for this . Their syntax is given below

AA ^ ( FNAME ) YXXXX ~ BB

where
AA is the line located before the inserted character,
FNAME is the name of the font from which the character is taken,
Y is the modifier for representing the character code (similar to @),
XXXX is the numeric code of the character being inserted,
BB - a string located after the inserted character.

By its purpose, the control character ^ is similar to @. They even have a similar syntax. But there are two important differences between them:

  1. ^ inserts not a special character, but a font character by its code;
  2. for the character to be inserted, you can set the font in the FNAME field (@ does not allow this).

Symbol codes can be viewed using the charmap application (Symbol Table), which is part of the Windows operating system.

If no font is specified, the default font is used. The following is an example using the ^ character .

BSTR str = SysAllocString(OLESTR("До ^(Arial)*B1~ Между ^*39~ После"));
document2D->ksText(100.0,100.0,0.0,0.0,0.0,0,str);
SysFreeString(str);

In this example, two characters are inserted into the resulting string, for the first we select the font Arial , for the second we leave the default font. The figure below shows the line that is output to the document.



Please note: the font is set only for the displayed character. As my experiments show, KOMPAS normally processes the absence of a ~ terminator . However, I do not recommend relying on this behavior and always setting a finalizer.

If an invalid character (or an invalid code) is specified after ^ , then ^ and ~ are omitted, and the line between them is displayed as is using the default font. For example, with the line

“Before ^ Q (Arial) * B1 ~ After”

The document will display:

“Before Q (Arial) * B1 After”

If an incorrect font name is indicated in the FNAME field , then COMPAS will select the font and display the character in it.

If there is no closing parenthesis in the line, then such a line will not be fully displayed. For example, with the line:

“Before ^ Q (Arial * B1 ~ After”

Only

“Before” will be displayed in the document

Note: the above behavior with incorrect control character syntax is valid for KOMPAS-3D V17 and is not documented. In other versions, it may differ .

Additional ways to insert characters


The characters @ and ^ have analogues - & and # respectively. They have similar syntax:

AA & XX ~ BB
AA # ( FNAME ) XX ~ BB


where

AA is the line displayed before the inserted character,
XX is the code of the inserted character (for & is the special character, for # is the font character),
BB is the string, displayed after the character to be inserted,
FNAME is the name of the font.

There are only two differences between the @ and ^ characters and their counterparts:

  1. The & and # characters do not have a Y modifier. The character code is always specified in decimal notation.
  2. The code for the character to be inserted is specified by a maximum of two digits.

The following is the source code for a program demonstrating how to use the & and # characters .

BSTR str = SysAllocString(OLESTR("До &51~ После"));
document2D->ksText(100.0,100.0,0.0,0.0,0.0,0,str);
SysFreeString(str);
str = SysAllocString(OLESTR("До #(Arial)37~ Между #37~ После"));
document2D->ksText(100.0,90.0,0.0,0.0,0.0,0,str);
SysFreeString(str);

The figure below shows the result of this program.



Multiline text


Using control characters, multi-line text can be displayed. To do this, in the place of transfer to a new line, you need to insert the sequence: @ / . Note: the @ character is used without a terminator ~ . The following is the source code for a program that displays multiline text using control characters.

BSTR str = SysAllocString(OLESTR("Первая строка@/Вторая строка"));
document2D->ksText(100.0,100.0,0.0,0.0,0.0,0,str);
SysFreeString(str);

Please note: thanks to the use of control characters, we display two-line text with just one call to the ksText method . The figure below shows the result of this program.



Insert control characters


We figured out how to insert arbitrary special characters and Unicode characters. But what if you want to insert the control character itself? Here you can go in two ways. The first way is to use the ^ character and paste them like regular font characters. But there is an easier way.

Symbol ; is auxiliary and can be inserted directly into the text. To insert other control characters, you need to double them. That is, a pair of @@ characters inserts a single @ character into the text . The same is true for other control characters.

The following is an example program that demonstrates inserting control characters in a string.

BSTR str = SysAllocString(OLESTR("Управляющие символы: @@ $$ && ; ~~ ^^ ##"));
document2D->ksText(100.0,100.0,0.0,0.0,0.0,0,str);
SysFreeString(str);

The figure below shows the result of this program.



Upper and lower deviations


The following syntax is used to insert deviations:

AA $ XX ; YY $ BB

where

AA is the text displayed before deviations;
XX - upper deviation;
YY is the lower deviation;
BB - text displayed after deviations.

Please note: the whole construction is limited to $ characters , and the “ ; »Serves as a separator between the upper and lower deviations.

If there is no delimiter " between the characters $ ; ", Then the entire line between them is interpreted as the top deviation. If component XXabsent, that is, after the first $ immediately goes " ; ", Then the entire subsequent line to the nearest $ is interpreted as the lower deviation.

Note: the text of the upper deviation should not begin with the letters b , d , s , m and l (lowercase L ). The reason for this will be explained a bit later.

The following is an example of a program that displays output with deviations

BSTR str = SysAllocString(OLESTR("До $Верхнее;Нижнее$ После"));
document2D->ksText(100.0,100.0,0.0,0.0,0.0,0,str);
SysFreeString(str);

The figure below shows the result of this program:



Note that KOMPAS processes only one character “ ; ". The second character is " ; "Can be interpreted as the finalizer of the entire structure. For example, if the line “ 11 $ 22; 33; 44 $ ” appears on the screen:



Note: this behavior of KOMPAS is not documented, so you can not rely on it.

Fraction


The fraction syntax is similar to the deviation syntax and has two equivalent options:

AA $ bXX ; YY $ BB
AA $ dXX ; YY $ BB


where

AA is the text displayed before the fraction;
XX is the numerator;
YY is the denominator;
BB - text displayed after the fraction.

Please note: the only difference between the output of the fraction and the output of deviations is the presence of the letter d or b immediately after the first sign of $ . Otherwise, their syntaxes are identical.

If between the characters $ d ($ b ) and $ there is no “ ; ", Then the entire line between them will be interpreted as a numerator. If component XX is absent, that is, after $ d ( $ b ) immediately comes " ; ", Then the entire subsequent line to the nearest $ is interpreted as the denominator.

Note: the numerator text must not begin with the letters s , m or l (lowercase L ). The reason for this will be explained a bit later.

The following is an example of a program that demonstrates fraction output using control characters.

BSTR str = SysAllocString(OLESTR("До $dЧислитель;Знаменатель$ После"));
document2D->ksText(100.0,100.0,0.0,0.0,0.0,0,str);
SysFreeString(str);

The figure below shows the result of this program.



Please note that KOMPAS processes the "extra" characters " ; »As well as in the case of deviations. This behavior is undocumented and cannot be relied upon.

Variation and fraction size control


At the very beginning of the construction of deviations or fractions, one of the letters can be located: s , m or l (lowercase L ). They specify the size of deviations and elements of the fraction (numerator and denominator). Their purpose is described in the table below.



If none of these letters is specified, then l is used for the fraction , and m is used for deviations . The following is an example program that demonstrates the use of these letters.

BSTR str = SysAllocString(OLESTR("До $dЧислитель;Знаменатель$ После"));
document2D->ksText(100.0,100.0,0.0,0.0,0.0,0,str);
SysFreeString(str);
str = SysAllocString(OLESTR("До $dlЧислитель;Знаменатель$ После"));
document2D->ksText(100.0,85.0,0.0,0.0,0.0,0,str);
SysFreeString(str);
str = SysAllocString(OLESTR("До $dmЧислитель;Знаменатель$ После"));
document2D->ksText(100.0,70.0,0.0,0.0,0.0,0,str);
SysFreeString(str);
str = SysAllocString(OLESTR("До $dsЧислитель;Знаменатель$ После"));
document2D->ksText(100.0,60.0,0.0,0.0,0.0,0,str);
SysFreeString(str);

The figure below shows the result of this program.



Although the letters s , m, and l are used for fractions in this example , their use for deviations is no different.

Note that if between the beginning of a fraction or deviation ( $ , $ d or $ b ) and the letter s , m or l there is at least one “extraneous” character (for example, a space), then COMPAS will not “see” the letters, and the fraction or Deviation will be the default size.

Nested control characters


When outputting fractions and deviations, the lines included in their composition are processed recursively. This means that when forming the numerator and denominator, control characters can also be used. This approach is demonstrated in the following example.

BSTR str = SysAllocString(OLESTR("@54~$s2$ + $d@+51~;@+52~$ - ^(Symbol)*70~"));
document2D->ksText(100.0,100.0,0.0,0.0,0.0,0,str);
SysFreeString(str);

The figure below shows the result of this program.



To insert letters of the Greek alphabet, we use the control characters @ and ^ (for the letter  pi). The degree in the first term is derived using deviations. The substring $ s2 $ displays it . The letter s indicates the small size of the deviation, but due to the absence of a separator " ; »Only the upper deviation is displayed.

To form a fraction, the combination $ d; $ is used . Moreover, the numerator and denominator include control characters that provide the output of the letters of the Greek alphabet.

The last subtracted (π pi) is displayed as the symbol of the Symbol font using the control characters ^ and ~ .

Unfortunately, the possibilities of such "recursion" are very limited. We cannot invest fractions and deviations into each other. The problem is that both of them are formed using the $ control character . Because of this, COMPASS cannot correctly parse which $ belongs to which element.

Control characters in paragraph


You can partially bypass the restriction with nested control characters using paragraphs. Using control characters and paragraphs together allows you to build even more complex structures. The example below demonstrates the construction of a 4-level fraction.

Program code for building a 4-level fraction
//Получаем нужные интерфейсы
DynamicArrayPtr dynamicArray;
dynamicArray = static_cast(kompas->GetDynamicArray(TEXT_ITEM_ARR));
dynamicArray->ksClearArray();
TextItemParamPtr textItemParam;
textItemParam = static_cast(kompas->GetParamStruct(ko_TextItemParam));
//Добавляем в массив обычный текст
BSTR str = SysAllocString(OLESTR("Текст до дроби"));
textItemParam->set_s(str);
dynamicArray->ksAddArrayItem(-1, textItemParam);
SysFreeString(str);
//Добавляем в массив числитель дроби
TextItemFontPtr textItemFont;
textItemFont = static_cast(textItemParam->GetItemFont());
textItemFont->set_bitVector(NUMERATOR);
str = SysAllocString(OLESTR("1 + $d@+51~;2$"));
textItemParam->set_s(str);
dynamicArray->ksAddArrayItem(-1, textItemParam);
SysFreeString(str);
//Добавляем в массив знаменатель
textItemFont->set_bitVector(DENOMINATOR);
str = SysAllocString(OLESTR("1 + $d@+56~;2$"));
textItemParam->set_s(str);
dynamicArray->ksAddArrayItem(-1, textItemParam);
SysFreeString(str);
//Завершаем дробь
textItemFont->set_bitVector(END_FRACTION);
str = SysAllocString(OLESTR("Текст после дроби"));
textItemParam->set_s(str);
dynamicArray->ksAddArrayItem(-1, textItemParam);
SysFreeString(str);
//Освобождаем ненужные интерфейсы
textItemFont.Unbind();
textItemParam.Unbind();
//Оформляем массив в интерфейс ksTextLineParam
TextLineParamPtr textLineParam;
textLineParam = static_cast(kompas->GetParamStruct(ko_TextLineParam));
textLineParam->Init();
textLineParam->SetTextItemArr(dynamicArray);
dynamicArray.Unbind();
//Строим параграф
ParagraphParamPtr paragraphParam;
paragraphParam=static_cast(kompas->GetParamStruct(ko_ParagraphParam));
paragraphParam->Init();
paragraphParam->set_x(100.0);
paragraphParam->set_y(100.0);
document2D->ksParagraph(paragraphParam);
document2D->ksTextLine(textLineParam);
document2D->ksEndObj();
//Освобождаем оставшиеся интерфейсы
textLineParam.Unbind();
paragraphParam.Unbind();


In this example, control characters are used to construct fractions in the numerator and denominator of the main fraction, as well as to insert letters of the Greek alphabet. The figure below shows the result of this program.



Conclusion


In this lesson, we met with control characters and learned how to use them to display special characters and font characters. As you can see, they provide a simple syntax for creating strings that include special characters, fractions, and deviations. Unfortunately, they are not well suited for inserting special characters containing strings. But such special characters are extremely rare. This is one of the limitations of control characters. Also, they cannot be used to create substrings and substrings, and there are limitations when working with special characters that include strings. But this does not detract from their merits. This concludes our discussion of control characters.

To be continued, follow the news of the blog.

Sergey Norseev, Ph.D., author of the book "Application Development for COMPAS in Delphi."

Also popular now: