Tk Source Code

typedef struct TextLayout {
    Tk_Font tkfont;		/* The font used when laying out the text. */
    const char *string;		/* The string that was layed out. */
    int width;			/* The maximum width of all lines in the text
				 * layout. */
    int numChunks;		/* Number of chunks actually used in following
				 * array. */
    LayoutChunk chunks[1];	/* Array of chunks. The actual size will be
    LayoutChunk chunks[TKFLEXARRAY];/* Array of chunks. The actual size will be
				 * maxChunks. THIS FIELD MUST BE THE LAST IN
				 * THE STRUCTURE. */
} TextLayout;

/*
 * The following structures are used as two-way maps between the values for
 * the fields in the TkFontAttributes structure and the strings used in Tcl,

#ifndef TkSizeT
#   if TCL_MAJOR_VERSION > 8
#	define TkSizeT size_t
#   else
#	define TkSizeT int
#   endif
#endif

#if defined(__GNUC__) && (__GNUC__ > 2)
#   define TKFLEXARRAY 0
#else
#   define TKFLEXARRAY 1
#endif

#if (TCL_MAJOR_VERSION == 8) && (TCL_MINOR_VERSION < 7)
# define Tcl_WCharToUtfDString ((char * (*)(const WCHAR *, int len, Tcl_DString *))Tcl_UniCharToUtfDString)
# define Tcl_UtfToWCharDString ((WCHAR * (*)(const char *, int len, Tcl_DString *))Tcl_UtfToUniCharDString)
# define Tcl_Char16ToUtfDString Tcl_UniCharToUtfDString
# define Tcl_UtfToChar16DString Tcl_UtfToUniCharDString
#endif

    Tcl_Interp *interp;		/* Interpreter in which to invoke command. */
    int cmdLength;		/* # of non-NULL bytes in command. */
    int charOffset;		/* The offset of the next char to retrieve. */
    int byteOffset;		/* The expected byte offset of the next
				 * chunk. */
    char buffer[4];		/* A buffer to hold part of a UTF character
				 * that is split across chunks. */
    char command[1];		/* Command to invoke. Actual space is
    char command[TKFLEXARRAY];		/* Command to invoke. Actual space is
				 * allocated as large as necessary. This must
				 * be the last entry in the structure. */
} CommandInfo;

/*
 * When selection ownership is claimed with the "selection own" Tcl command,
 * one of the following structures is created to record the Tcl command to be

				 * type. */
    struct TkTextSegment *nextPtr;
				/* Next in list of segments for this line, or
				 * NULL for end of list. */
    TkSizeT size;			/* Size of this segment (# of bytes of index
				 * space it occupies). */
    union {
	char chars[2];		/* Characters that make up character info.
	char chars[TKFLEXARRAY];		/* Characters that make up character info.
				 * Actual length varies to hold as many
				 * characters as needed.*/
	TkTextToggle toggle;	/* Information about tag toggle. */
	TkTextMark mark;	/* Information about mark. */
	TkTextEmbWindow ew;	/* Information about embedded window. */
	TkTextEmbImage ei;	/* Information about embedded image. */
    } body;

typedef struct TkTextTabArray {
    int numTabs;		/* Number of tab stops. */
    double lastTab;		/* The accurate fractional pixel position of
				 * the last tab. */
    double tabIncrement;	/* The accurate fractional pixel increment
				 * between interpolated tabs we have to create
				 * when we exceed numTabs. */
    TkTextTab tabs[1];		/* Array of tabs. The actual size will be
    TkTextTab tabs[TKFLEXARRAY];/* Array of tabs. The actual size will be
				 * numTabs. THIS FIELD MUST BE THE LAST IN THE
				 * STRUCTURE. */
} TkTextTabArray;

/*
 * Enumeration defining the edit modes of the widget.
 */

 * points to one of the following structures:
 */

#if !TK_LAYOUT_WITH_BASE_CHUNKS

typedef struct CharInfo {
    int numBytes;		/* Number of bytes to display. */
    char chars[1];		/* UTF characters to display.
    char chars[TKFLEXARRAY];		/* UTF characters to display.
				 * Allocated as large as necessary. THIS MUST BE THE LAST
				 * FIELD IN THE STRUCTURE. */
} CharInfo;

#else /* TK_LAYOUT_WITH_BASE_CHUNKS */

typedef struct CharInfo {

typedef struct ProtocolHandler {
    Atom protocol;		/* Identifies the protocol. */
    struct ProtocolHandler *nextPtr;
				/* Next in list of protocol handlers for the
				 * same top-level window, or NULL for end of
				 * list. */
    Tcl_Interp *interp;	/* Interpreter in which to invoke command. */
    char command[1];		/* Tcl command to invoke when a client message
    char command[TKFLEXARRAY];	/* Tcl command to invoke when a client message
				 * for this protocol arrives. The actual size
				 * of the structure varies to accommodate the
				 * needs of the actual command. THIS MUST BE
				 * THE LAST FIELD OF THE STRUCTURE. */
} ProtocolHandler;

#define HANDLER_SIZE(cmdLength) \

typedef struct ProtocolHandler {
    Atom protocol;		/* Identifies the protocol. */
    struct ProtocolHandler *nextPtr;
				/* Next in list of protocol handlers for the
				 * same top-level window, or NULL for end of
				 * list. */
    Tcl_Interp *interp;	/* Interpreter in which to invoke command. */
    char command[1];		/* Tcl command to invoke when a client message
    char command[TKFLEXARRAY];	/* Tcl command to invoke when a client message
				 * for this protocol arrives. The actual size
				 * of the structure varies to accommodate the
				 * needs of the actual command. THIS MUST BE
				 * THE LAST FIELD OF THE STRUCTURE. */
} ProtocolHandler;

#define HANDLER_SIZE(cmdLength) \