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TGFont Class Reference

Encapsulate fonts used in the GUI system.

Definition at line 140 of file TGFont.h.

Public Member Functions

virtual ~TGFont ()
 Delete font.
 
TGTextLayoutComputeTextLayout (const char *string, Int_t numChars, Int_t wrapLength, Int_t justify, Int_t flags, UInt_t *width, UInt_t *height) const
 Computes the amount of screen space needed to display a multi-line, justified string of text.
 
void DrawChars (Drawable_t dst, GContext_t gc, const char *source, Int_t numChars, Int_t x, Int_t y) const
 Perform a quick sanity check to ensure we won't overflow the X coordinate space.
 
void DrawCharsExp (Drawable_t dst, GContext_t gc, const char *source, Int_t numChars, Int_t x, Int_t y) const
 Draw a string of characters on the screen.
 
FontAttributes_t GetFontAttributes () const
 
FontH_t GetFontHandle () const
 
void GetFontMetrics (FontMetrics_t *m) const
 Get font metrics.
 
FontStruct_t GetFontStruct () const
 
Int_t MeasureChars (const char *source, Int_t numChars, Int_t maxLength, Int_t flags, Int_t *length) const
 Determine the number of characters from the string that will fit in the given horizontal span.
 
FontStruct_t operator() () const
 Not inline due to a bug in g++ 2.96 20000731 (Red Hat Linux 7.0)
 
Int_t PostscriptFontName (TString *dst) const
 Return the name of the corresponding Postscript font for this TGFont.
 
void Print (Option_t *option="") const
 Print font info.
 
virtual void SavePrimitive (std::ostream &out, Option_t *="")
 Save the used font as a C++ statement(s) on output stream out.
 
Int_t TextHeight () const
 
Int_t TextWidth (const char *string, Int_t numChars=-1) const
 A wrapper function for the more complicated interface of MeasureChars.
 
void UnderlineChars (Drawable_t dst, GContext_t gc, const char *string, Int_t x, Int_t y, Int_t firstChar, Int_t lastChar) const
 This procedure draws an underline for a given range of characters in a given string.
 
Int_t XTextWidth (const char *string, Int_t numChars=-1) const
 Return text width in pixels.
 
- Public Member Functions inherited from TNamed
 TNamed ()
 
 TNamed (const char *name, const char *title)
 
 TNamed (const TNamed &named)
 TNamed copy ctor.
 
 TNamed (const TString &name, const TString &title)
 
virtual ~TNamed ()
 TNamed destructor.
 
virtual void Clear (Option_t *option="")
 Set name and title to empty strings ("").
 
virtual TObjectClone (const char *newname="") const
 Make a clone of an object using the Streamer facility.
 
virtual Int_t Compare (const TObject *obj) const
 Compare two TNamed objects.
 
virtual void Copy (TObject &named) const
 Copy this to obj.
 
virtual void FillBuffer (char *&buffer)
 Encode TNamed into output buffer.
 
virtual const char * GetName () const
 Returns name of object.
 
virtual const char * GetTitle () const
 Returns title of object.
 
virtual ULong_t Hash () const
 Return hash value for this object.
 
virtual Bool_t IsSortable () const
 
virtual void ls (Option_t *option="") const
 List TNamed name and title.
 
TNamedoperator= (const TNamed &rhs)
 TNamed assignment operator.
 
virtual void SetName (const char *name)
 Set the name of the TNamed.
 
virtual void SetNameTitle (const char *name, const char *title)
 Set all the TNamed parameters (name and title).
 
virtual void SetTitle (const char *title="")
 Set the title of the TNamed.
 
virtual Int_t Sizeof () const
 Return size of the TNamed part of the TObject.
 
- Public Member Functions inherited from TObject
 TObject ()
 TObject constructor.
 
 TObject (const TObject &object)
 TObject copy ctor.
 
virtual ~TObject ()
 TObject destructor.
 
void AbstractMethod (const char *method) const
 Use this method to implement an "abstract" method that you don't want to leave purely abstract.
 
virtual void AppendPad (Option_t *option="")
 Append graphics object to current pad.
 
virtual void Browse (TBrowser *b)
 Browse object. May be overridden for another default action.
 
ULong_t CheckedHash ()
 Check and record whether this class has a consistent Hash/RecursiveRemove setup (*) and then return the regular Hash value for this object.
 
virtual const char * ClassName () const
 Returns name of class to which the object belongs.
 
virtual void Delete (Option_t *option="")
 Delete this object.
 
virtual Int_t DistancetoPrimitive (Int_t px, Int_t py)
 Computes distance from point (px,py) to the object.
 
virtual void Draw (Option_t *option="")
 Default Draw method for all objects.
 
virtual void DrawClass () const
 Draw class inheritance tree of the class to which this object belongs.
 
virtual TObjectDrawClone (Option_t *option="") const
 Draw a clone of this object in the current selected pad for instance with: gROOT->SetSelectedPad(gPad).
 
virtual void Dump () const
 Dump contents of object on stdout.
 
virtual void Error (const char *method, const char *msgfmt,...) const
 Issue error message.
 
virtual void Execute (const char *method, const char *params, Int_t *error=0)
 Execute method on this object with the given parameter string, e.g.
 
virtual void Execute (TMethod *method, TObjArray *params, Int_t *error=0)
 Execute method on this object with parameters stored in the TObjArray.
 
virtual void ExecuteEvent (Int_t event, Int_t px, Int_t py)
 Execute action corresponding to an event at (px,py).
 
virtual void Fatal (const char *method, const char *msgfmt,...) const
 Issue fatal error message.
 
virtual TObjectFindObject (const char *name) const
 Must be redefined in derived classes.
 
virtual TObjectFindObject (const TObject *obj) const
 Must be redefined in derived classes.
 
virtual Option_tGetDrawOption () const
 Get option used by the graphics system to draw this object.
 
virtual const char * GetIconName () const
 Returns mime type name of object.
 
virtual char * GetObjectInfo (Int_t px, Int_t py) const
 Returns string containing info about the object at position (px,py).
 
virtual Option_tGetOption () const
 
virtual UInt_t GetUniqueID () const
 Return the unique object id.
 
virtual Bool_t HandleTimer (TTimer *timer)
 Execute action in response of a timer timing out.
 
Bool_t HasInconsistentHash () const
 Return true is the type of this object is known to have an inconsistent setup for Hash and RecursiveRemove (i.e.
 
virtual void Info (const char *method, const char *msgfmt,...) const
 Issue info message.
 
virtual Bool_t InheritsFrom (const char *classname) const
 Returns kTRUE if object inherits from class "classname".
 
virtual Bool_t InheritsFrom (const TClass *cl) const
 Returns kTRUE if object inherits from TClass cl.
 
virtual void Inspect () const
 Dump contents of this object in a graphics canvas.
 
void InvertBit (UInt_t f)
 
Bool_t IsDestructed () const
 IsDestructed.
 
virtual Bool_t IsEqual (const TObject *obj) const
 Default equal comparison (objects are equal if they have the same address in memory).
 
virtual Bool_t IsFolder () const
 Returns kTRUE in case object contains browsable objects (like containers or lists of other objects).
 
R__ALWAYS_INLINE Bool_t IsOnHeap () const
 
R__ALWAYS_INLINE Bool_t IsZombie () const
 
void MayNotUse (const char *method) const
 Use this method to signal that a method (defined in a base class) may not be called in a derived class (in principle against good design since a child class should not provide less functionality than its parent, however, sometimes it is necessary).
 
virtual Bool_t Notify ()
 This method must be overridden to handle object notification.
 
void Obsolete (const char *method, const char *asOfVers, const char *removedFromVers) const
 Use this method to declare a method obsolete.
 
void operator delete (void *ptr)
 Operator delete.
 
void operator delete[] (void *ptr)
 Operator delete [].
 
voidoperator new (size_t sz)
 
voidoperator new (size_t sz, void *vp)
 
voidoperator new[] (size_t sz)
 
voidoperator new[] (size_t sz, void *vp)
 
TObjectoperator= (const TObject &rhs)
 TObject assignment operator.
 
virtual void Paint (Option_t *option="")
 This method must be overridden if a class wants to paint itself.
 
virtual void Pop ()
 Pop on object drawn in a pad to the top of the display list.
 
virtual Int_t Read (const char *name)
 Read contents of object with specified name from the current directory.
 
virtual void RecursiveRemove (TObject *obj)
 Recursively remove this object from a list.
 
void ResetBit (UInt_t f)
 
virtual void SaveAs (const char *filename="", Option_t *option="") const
 Save this object in the file specified by filename.
 
void SetBit (UInt_t f)
 
void SetBit (UInt_t f, Bool_t set)
 Set or unset the user status bits as specified in f.
 
virtual void SetDrawOption (Option_t *option="")
 Set drawing option for object.
 
virtual void SetUniqueID (UInt_t uid)
 Set the unique object id.
 
virtual void SysError (const char *method, const char *msgfmt,...) const
 Issue system error message.
 
R__ALWAYS_INLINE Bool_t TestBit (UInt_t f) const
 
Int_t TestBits (UInt_t f) const
 
virtual void UseCurrentStyle ()
 Set current style settings in this object This function is called when either TCanvas::UseCurrentStyle or TROOT::ForceStyle have been invoked.
 
virtual void Warning (const char *method, const char *msgfmt,...) const
 Issue warning message.
 
virtual Int_t Write (const char *name=0, Int_t option=0, Int_t bufsize=0)
 Write this object to the current directory.
 
virtual Int_t Write (const char *name=0, Int_t option=0, Int_t bufsize=0) const
 Write this object to the current directory.
 
- Public Member Functions inherited from TRefCnt
 TRefCnt (EReferenceFlag)
 Leave fRefs alone.
 
 TRefCnt (Int_t initRef=0)
 
virtual ~TRefCnt ()
 
void AddReference ()
 
UInt_t References () const
 
UInt_t RemoveReference ()
 
void SetRefCount (UInt_t r)
 

Protected Member Functions

 TGFont (const char *name)
 
 TGFont (const TGFont &)=delete
 
LayoutChunk_tNewChunk (TGTextLayout *layout, int *maxPtr, const char *start, int numChars, int curX, int newX, int y) const
 Helper function for ComputeTextLayout().
 
void operator= (const TGFont &)=delete
 
- Protected Member Functions inherited from TObject
virtual void DoError (int level, const char *location, const char *fmt, va_list va) const
 Interface to ErrorHandler (protected).
 
void MakeZombie ()
 

Private Attributes

Int_t fBarHeight
 Height of underline or overstrike bar (used for simulating a native underlined or strikeout font).
 
FontAttributes_t fFA
 Actual font attributes obtained when the font was created.
 
FontMetrics_t fFM
 Cached font metrics.
 
FontH_t fFontH
 Font handle (derived from fontstruct)
 
FontStruct_t fFontStruct
 Low level graphics fontstruct.
 
TObjStringfNamedHash
 Pointer to the named object TGFont was based on.
 
Int_t fTabWidth
 Width of tabs in this font (pixels).
 
char fTypes [256]
 Array giving types of all characters in the font, used when displaying control characters.
 
Int_t fUnderlineHeight
 Height of underline bar (used for drawing underlines on a non-underlined font).
 
Int_t fUnderlinePos
 Offset from baseline to origin of underline bar (used for drawing underlines on a non-underlined font).
 
Int_t fWidths [256]
 Array giving widths of all possible characters in the font.
 

Friends

class TGFontPool
 
class TGTextLayout
 

Additional Inherited Members

- Public Types inherited from TObject
enum  {
  kIsOnHeap = 0x01000000 , kNotDeleted = 0x02000000 , kZombie = 0x04000000 , kInconsistent = 0x08000000 ,
  kBitMask = 0x00ffffff
}
 
enum  { kSingleKey = BIT(0) , kOverwrite = BIT(1) , kWriteDelete = BIT(2) }
 
enum  EDeprecatedStatusBits { kObjInCanvas = BIT(3) }
 
enum  EStatusBits {
  kCanDelete = BIT(0) , kMustCleanup = BIT(3) , kIsReferenced = BIT(4) , kHasUUID = BIT(5) ,
  kCannotPick = BIT(6) , kNoContextMenu = BIT(8) , kInvalidObject = BIT(13)
}
 
- Public Types inherited from TRefCnt
enum  EReferenceFlag { kStaticInit }
 
- Static Public Member Functions inherited from TObject
static Longptr_t GetDtorOnly ()
 Return destructor only flag.
 
static Bool_t GetObjectStat ()
 Get status of object stat flag.
 
static void SetDtorOnly (void *obj)
 Set destructor only flag.
 
static void SetObjectStat (Bool_t stat)
 Turn on/off tracking of objects in the TObjectTable.
 
- Protected Types inherited from TObject
enum  { kOnlyPrepStep = BIT(3) }
 
- Protected Attributes inherited from TNamed
TString fName
 
TString fTitle
 
- Protected Attributes inherited from TRefCnt
UInt_t fRefs
 

#include <TGFont.h>

Inheritance diagram for TGFont:
[legend]

Constructor & Destructor Documentation

◆ TGFont() [1/2]

TGFont::TGFont ( const char *  name)
inlineprotected

Definition at line 163 of file TGFont.h.

◆ TGFont() [2/2]

TGFont::TGFont ( const TGFont )
protecteddelete

◆ ~TGFont()

TGFont::~TGFont ( )
virtual

Delete font.

Definition at line 276 of file TGFont.cxx.

Member Function Documentation

◆ ComputeTextLayout()

TGTextLayout * TGFont::ComputeTextLayout ( const char *  string,
Int_t  numChars,
Int_t  wrapLength,
Int_t  justify,
Int_t  flags,
UInt_t width,
UInt_t height 
) const

Computes the amount of screen space needed to display a multi-line, justified string of text.

Records all the measurements that were done to determine to size and positioning of the individual lines of text; this information can be used by the TGTextLayout::DrawText() procedure to display the text quickly (without remeasuring it).

This procedure is useful for simple widgets that want to display single-font, multi-line text and want TGFont to handle the details.

The return value is a TGTextLayout token that holds the measurement information for the given string. The token is only valid for the given string. If the string is freed, the token is no longer valid and must also be deleted.

The dimensions of the screen area needed to display the text are stored in *width and *height.

string – String whose dimensions are to be computed. numChars – Number of characters to consider from string, or < 0 for strlen(). wrapLength – Longest permissible line length, in pixels. <= 0 means no automatic wrapping: just let lines get as long as needed. justify – How to justify lines. flags – Flag bits OR-ed together. kTextIgnoreTabs means that tab characters should not be expanded. kTextIgnoreNewlines means that newline characters should not cause a line break. width – Filled with width of string. height – Filled with height of string.

Definition at line 661 of file TGFont.cxx.

◆ DrawChars()

void TGFont::DrawChars ( Drawable_t  dst,
GContext_t  gc,
const char *  source,
Int_t  numChars,
Int_t  x,
Int_t  y 
) const

Perform a quick sanity check to ensure we won't overflow the X coordinate space.

Definition at line 1493 of file TGFont.cxx.

◆ DrawCharsExp()

void TGFont::DrawCharsExp ( Drawable_t  dst,
GContext_t  gc,
const char *  source,
Int_t  numChars,
Int_t  x,
Int_t  y 
) const

Draw a string of characters on the screen.

DrawCharsExp() expands control characters that occur in the string to \X or \xXX sequences. DrawChars() just draws the strings.

dst – Window or pixmap in which to draw. gc – Graphics context for drawing characters. source – Characters to be displayed. Need not be'\0' terminated. For DrawChars(), all meta-characters (tabs, control characters, and newlines) should be stripped out of the string that is passed to this function. If they are not stripped out, they will be displayed as regular printing characters. numChars – Number of characters in string. x, y – Coordinates at which to place origin of string when drawing.

Definition at line 1463 of file TGFont.cxx.

◆ GetFontAttributes()

FontAttributes_t TGFont::GetFontAttributes ( ) const
inline

Definition at line 187 of file TGFont.h.

◆ GetFontHandle()

FontH_t TGFont::GetFontHandle ( ) const
inline

Definition at line 183 of file TGFont.h.

◆ GetFontMetrics()

void TGFont::GetFontMetrics ( FontMetrics_t m) const

Get font metrics.

Definition at line 286 of file TGFont.cxx.

◆ GetFontStruct()

FontStruct_t TGFont::GetFontStruct ( ) const
inline

Definition at line 184 of file TGFont.h.

◆ MeasureChars()

Int_t TGFont::MeasureChars ( const char *  source,
Int_t  numChars,
Int_t  maxLength,
Int_t  flags,
Int_t length 
) const

Determine the number of characters from the string that will fit in the given horizontal span.

The measurement is done under the assumption that DrawChars() will be used to actually display the characters.

The return value is the number of characters from source that fit into the span that extends from 0 to maxLength. *length is filled with the x-coordinate of the right edge of the last character that did fit.

source – Characters to be displayed. Need not be '\0' terminated. numChars – Maximum number of characters to consider from source string. maxLength – If > 0, maxLength specifies the longest permissible line length; don't consider any character that would cross this x-position. If <= 0, then line length is unbounded and the flags argument is ignored. flags – Various flag bits OR-ed together: TEXT_PARTIAL_OK means include the last char which only partially fit on this line. TEXT_WHOLE_WORDS means stop on a word boundary, if possible. TEXT_AT_LEAST_ONE means return at least one character even if no characters fit. *length – Filled with x-location just after the terminating character.

Definition at line 488 of file TGFont.cxx.

◆ NewChunk()

LayoutChunk_t * TGFont::NewChunk ( TGTextLayout layout,
int maxPtr,
const char *  start,
int  numChars,
int  curX,
int  newX,
int  y 
) const
protected

Helper function for ComputeTextLayout().

Encapsulates a measured set of characters in a chunk that can be quickly drawn.

Returns a pointer to the new chunk in the text layout. The text layout is reallocated to hold more chunks as necessary.

Currently, ComputeTextLayout() stores contiguous ranges of "normal" characters in a chunk, along with individual tab and newline chars in their own chunks. All characters in the text layout are accounted for.

Definition at line 1410 of file TGFont.cxx.

◆ operator()()

FontStruct_t TGFont::operator() ( ) const

Not inline due to a bug in g++ 2.96 20000731 (Red Hat Linux 7.0)

Definition at line 300 of file TGFont.cxx.

◆ operator=()

void TGFont::operator= ( const TGFont )
protecteddelete

◆ PostscriptFontName()

Int_t TGFont::PostscriptFontName ( TString dst) const

Return the name of the corresponding Postscript font for this TGFont.

The return value is the pointsize of the TGFont. The name of the Postscript font is appended to ds.

If the font does not exist on the printer, the print job will fail at print time. Given a "reasonable" Postscript printer, the following TGFont font families should print correctly:

Avant Garde, Arial, Bookman, Courier, Courier New, Geneva,
Helvetica, Monaco, New Century Schoolbook, New York,
Palatino, Symbol, Times, Times New Roman, Zapf Chancery,
and Zapf Dingbats.

Any other TGFont font families may not print correctly because the computed Postscript font name may be incorrect.

dst – Pointer to an initialized TString object to which the name of the Postscript font that corresponds to the font will be appended.

Definition at line 343 of file TGFont.cxx.

◆ Print()

void TGFont::Print ( Option_t option = "") const
virtual

Print font info.

Reimplemented from TNamed.

Definition at line 308 of file TGFont.cxx.

◆ SavePrimitive()

void TGFont::SavePrimitive ( std::ostream &  out,
Option_t = "" 
)
virtual

Save the used font as a C++ statement(s) on output stream out.

Reimplemented from TObject.

Definition at line 1884 of file TGFont.cxx.

◆ TextHeight()

Int_t TGFont::TextHeight ( ) const
inline

Definition at line 192 of file TGFont.h.

◆ TextWidth()

Int_t TGFont::TextWidth ( const char *  string,
Int_t  numChars = -1 
) const

A wrapper function for the more complicated interface of MeasureChars.

Computes how much space the given simple string needs.

The return value is the width (in pixels) of the given string.

string – String whose width will be computed. numChars – Number of characters to consider from string, or < 0 for strlen().

Definition at line 575 of file TGFont.cxx.

◆ UnderlineChars()

void TGFont::UnderlineChars ( Drawable_t  dst,
GContext_t  gc,
const char *  string,
Int_t  x,
Int_t  y,
Int_t  firstChar,
Int_t  lastChar 
) const

This procedure draws an underline for a given range of characters in a given string.

It doesn't draw the characters (which are assumed to have been displayed previously); it just draws the underline. This procedure would mainly be used to quickly underline a few characters without having to construct an underlined font. To produce properly underlined text, the appropriate underlined font should be constructed and used.

dst – Window or pixmap in which to draw. gc – Graphics context for actually drawing line. string – String containing characters to be underlined or overstruck. x, y – Coordinates at which first character of string is drawn. firstChar – Index of first character. lastChar – Index of one after the last character.

Definition at line 617 of file TGFont.cxx.

◆ XTextWidth()

Int_t TGFont::XTextWidth ( const char *  string,
Int_t  numChars = -1 
) const

Return text width in pixels.

Definition at line 590 of file TGFont.cxx.

Friends And Related Symbol Documentation

◆ TGFontPool

friend class TGFontPool
friend

Definition at line 142 of file TGFont.h.

◆ TGTextLayout

friend class TGTextLayout
friend

Definition at line 143 of file TGFont.h.

Member Data Documentation

◆ fBarHeight

Int_t TGFont::fBarHeight
private

Height of underline or overstrike bar (used for simulating a native underlined or strikeout font).

Definition at line 159 of file TGFont.h.

◆ fFA

FontAttributes_t TGFont::fFA
private

Actual font attributes obtained when the font was created.

Definition at line 149 of file TGFont.h.

◆ fFM

FontMetrics_t TGFont::fFM
private

Cached font metrics.

Definition at line 148 of file TGFont.h.

◆ fFontH

FontH_t TGFont::fFontH
private

Font handle (derived from fontstruct)

Definition at line 147 of file TGFont.h.

◆ fFontStruct

FontStruct_t TGFont::fFontStruct
private

Low level graphics fontstruct.

Definition at line 146 of file TGFont.h.

◆ fNamedHash

TObjString* TGFont::fNamedHash
private

Pointer to the named object TGFont was based on.

Definition at line 150 of file TGFont.h.

◆ fTabWidth

Int_t TGFont::fTabWidth
private

Width of tabs in this font (pixels).

Definition at line 151 of file TGFont.h.

◆ fTypes

char TGFont::fTypes[256]
private

Array giving types of all characters in the font, used when displaying control characters.

Definition at line 156 of file TGFont.h.

◆ fUnderlineHeight

Int_t TGFont::fUnderlineHeight
private

Height of underline bar (used for drawing underlines on a non-underlined font).

Definition at line 154 of file TGFont.h.

◆ fUnderlinePos

Int_t TGFont::fUnderlinePos
private

Offset from baseline to origin of underline bar (used for drawing underlines on a non-underlined font).

Definition at line 152 of file TGFont.h.

◆ fWidths

Int_t TGFont::fWidths[256]
private

Array giving widths of all possible characters in the font.

Definition at line 158 of file TGFont.h.

Libraries for TGFont:

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