Version: 3.1.1

#include <wx/graphics.h>

+ Inheritance diagram for wxGraphicsContext:

Detailed Description

A wxGraphicsContext instance is the object that is drawn upon.

It is created by a renderer using wxGraphicsRenderer::CreateContext(). This can be either directly using a renderer instance, or indirectly using the static convenience Create() functions of wxGraphicsContext that always delegate the task to the default renderer.

void MyCanvas::OnPaint(wxPaintEvent &event)
{
// Create paint DC
wxPaintDC dc(this);
// Create graphics context from it
if (gc)
{
// make a path that contains a circle and some lines
gc->SetPen( *wxRED_PEN );
wxGraphicsPath path = gc->CreatePath();
path.AddCircle( 50.0, 50.0, 50.0 );
path.MoveToPoint(0.0, 50.0);
path.AddLineToPoint(100.0, 50.0);
path.MoveToPoint(50.0, 0.0);
path.AddLineToPoint(50.0, 100.0 );
path.CloseSubpath();
path.AddRectangle(25.0, 25.0, 50.0, 50.0);
gc->StrokePath(path);
delete gc;
}
}
Remarks
For some renderers (like Direct2D or Cairo) processing of drawing operations may be deferred (Direct2D render target normally builds up a batch of rendering commands but defers processing of these commands, Cairo operates on a separate surface) so to make drawing results visible you need to update the content of the context by calling wxGraphicsContext::Flush() or by destroying the context.

Library:  wxCore
Category:  Graphics Device Interface (GDI), Device Contexts
See also
wxGraphicsRenderer::CreateContext(), wxGCDC, wxDC

Public Member Functions

Clipping region functions
virtual void ResetClip ()=0
 Resets the clipping to original shape. More...
 
virtual void Clip (const wxRegion &region)=0
 Sets the clipping region to the intersection of the given region and the previously set clipping region. More...
 
virtual void Clip (wxDouble x, wxDouble y, wxDouble w, wxDouble h)=0
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...
 
Transformation matrix
virtual wxGraphicsMatrix CreateMatrix (wxDouble a=1.0, wxDouble b=0.0, wxDouble c=0.0, wxDouble d=1.0, wxDouble tx=0.0, wxDouble ty=0.0) const
 Creates a native affine transformation matrix from the passed in values. More...
 
wxGraphicsMatrix CreateMatrix (const wxAffineMatrix2DBase &mat) const
 Creates a native affine transformation matrix from the passed generic one. More...
 
virtual void ConcatTransform (const wxGraphicsMatrix &matrix)=0
 Concatenates the passed in transform with the current transform of this context. More...
 
virtual wxGraphicsMatrix GetTransform () const =0
 Gets the current transformation matrix of this context. More...
 
virtual void Rotate (wxDouble angle)=0
 Rotates the current transformation matrix (in radians). More...
 
virtual void Scale (wxDouble xScale, wxDouble yScale)=0
 Scales the current transformation matrix. More...
 
virtual void SetTransform (const wxGraphicsMatrix &matrix)=0
 Sets the current transformation matrix of this context. More...
 
virtual void Translate (wxDouble dx, wxDouble dy)=0
 Translates the current transformation matrix. More...
 
Brush and pen functions
virtual wxGraphicsBrush CreateBrush (const wxBrush &brush) const
 Creates a native brush from a wxBrush. More...
 
wxGraphicsBrush CreateLinearGradientBrush (wxDouble x1, wxDouble y1, wxDouble x2, wxDouble y2, const wxColour &c1, const wxColour &c2) const
 Creates a native brush with a linear gradient. More...
 
wxGraphicsBrush CreateLinearGradientBrush (wxDouble x1, wxDouble y1, wxDouble x2, wxDouble y2, const wxGraphicsGradientStops &stops) const
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...
 
virtual wxGraphicsBrush CreateRadialGradientBrush (wxDouble xo, wxDouble yo, wxDouble xc, wxDouble yc, wxDouble radius, const wxColour &oColor, const wxColour &cColor) const
 Creates a native brush with a radial gradient. More...
 
virtual wxGraphicsBrush CreateRadialGradientBrush (wxDouble xo, wxDouble yo, wxDouble xc, wxDouble yc, wxDouble radius, const wxGraphicsGradientStops &stops)=0
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...
 
void SetBrush (const wxBrush &brush)
 Sets the brush for filling paths. More...
 
virtual void SetBrush (const wxGraphicsBrush &brush)
 Sets the brush for filling paths. More...
 
virtual wxGraphicsPen CreatePen (const wxPen &pen) const
 Creates a native pen from a wxPen. More...
 
void SetPen (const wxPen &pen)
 Sets the pen used for stroking. More...
 
virtual void SetPen (const wxGraphicsPen &pen)
 Sets the pen used for stroking. More...
 
Drawing functions
virtual void DrawBitmap (const wxGraphicsBitmap &bmp, wxDouble x, wxDouble y, wxDouble w, wxDouble h)=0
 Draws the bitmap. More...
 
virtual void DrawBitmap (const wxBitmap &bmp, wxDouble x, wxDouble y, wxDouble w, wxDouble h)=0
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. More...
 
virtual void DrawEllipse (wxDouble x, wxDouble y, wxDouble w, wxDouble h)
 Draws an ellipse. More...
 
virtual void DrawIcon (const wxIcon &icon, wxDouble x, wxDouble y, wxDouble w, wxDouble h)=0
 Draws the icon. More...
 
virtual void DrawLines (size_t n, const wxPoint2DDouble *points, wxPolygonFillMode fillStyle=wxODDEVEN_RULE)
 Draws a polygon. More...
 
virtual void DrawPath (const wxGraphicsPath &path, wxPolygonFillMode fillStyle=wxODDEVEN_RULE)
 Draws the path by first filling and then stroking. More...
 
virtual void DrawRectangle (wxDouble x, wxDouble y, wxDouble w, wxDouble h)
 Draws a rectangle. More...
 
virtual void DrawRoundedRectangle (wxDouble x, wxDouble y, wxDouble w, wxDouble h, wxDouble radius)
 Draws a rounded rectangle. More...
 
void DrawText (const wxString &str, wxDouble x, wxDouble y)
 Draws text at the defined position. More...
 
void DrawText (const wxString &str, wxDouble x, wxDouble y, wxDouble angle)
 Draws text at the defined position. More...
 
void DrawText (const wxString &str, wxDouble x, wxDouble y, const wxGraphicsBrush &backgroundBrush)
 Draws text at the defined position. More...
 
void DrawText (const wxString &str, wxDouble x, wxDouble y, wxDouble angle, const wxGraphicsBrush &backgroundBrush)
 Draws text at the defined position. More...
 
wxGraphicsPath CreatePath () const
 Creates a native graphics path which is initially empty. More...
 
virtual void FillPath (const wxGraphicsPath &path, wxPolygonFillMode fillStyle=wxODDEVEN_RULE)=0
 Fills the path with the current brush. More...
 
virtual void StrokeLine (wxDouble x1, wxDouble y1, wxDouble x2, wxDouble y2)
 Strokes a single line. More...
 
virtual void StrokeLines (size_t n, const wxPoint2DDouble *beginPoints, const wxPoint2DDouble *endPoints)
 Stroke disconnected lines from begin to end points, fastest method available for this purpose. More...
 
virtual void StrokeLines (size_t n, const wxPoint2DDouble *points)
 Stroke lines connecting all the points. More...
 
virtual void StrokePath (const wxGraphicsPath &path)=0
 Strokes along a path with the current pen. More...
 
Text functions
virtual wxGraphicsFont CreateFont (const wxFont &font, const wxColour &col=*wxBLACK) const
 Creates a native graphics font from a wxFont and a text colour. More...
 
virtual wxGraphicsFont CreateFont (double sizeInPixels, const wxString &facename, int flags=wxFONTFLAG_DEFAULT, const wxColour &col=*wxBLACK) const
 Creates a font object with the specified attributes. More...
 
void SetFont (const wxFont &font, const wxColour &colour)
 Sets the font for drawing text. More...
 
virtual void SetFont (const wxGraphicsFont &font)
 Sets the font for drawing text. More...
 
virtual void GetPartialTextExtents (const wxString &text, wxArrayDouble &widths) const =0
 Fills the widths array with the widths from the beginning of text to the corresponding character of text. More...
 
virtual void GetTextExtent (const wxString &text, wxDouble *width, wxDouble *height, wxDouble *descent, wxDouble *externalLeading) const =0
 Gets the dimensions of the string using the currently selected font. More...
 
Page and document start/end functions
virtual bool StartDoc (const wxString &message)
 Begin a new document (relevant only for printing / pdf etc.) If there is a progress dialog, message will be shown. More...
 
virtual void EndDoc ()
 Done with that document (relevant only for printing / pdf etc.) More...
 
virtual void StartPage (wxDouble width=0, wxDouble height=0)
 Opens a new page (relevant only for printing / pdf etc.) with the given size in points. More...
 
virtual void EndPage ()
 Ends the current page (relevant only for printing / pdf etc.) More...
 
Bitmap functions
virtual wxGraphicsBitmap CreateBitmap (const wxBitmap &bitmap)=0
 Creates wxGraphicsBitmap from an existing wxBitmap. More...
 
virtual wxGraphicsBitmap CreateBitmapFromImage (const wxImage &image)
 Creates wxGraphicsBitmap from an existing wxImage. More...
 
virtual wxGraphicsBitmap CreateSubBitmap (const wxGraphicsBitmap &bitmap, wxDouble x, wxDouble y, wxDouble w, wxDouble h)=0
 Extracts a sub-bitmap from an existing bitmap. More...
 
Modifying the state
virtual void BeginLayer (wxDouble opacity)=0
 All rendering will be done into a fully transparent temporary context. More...
 
virtual void EndLayer ()=0
 Composites back the drawings into the context with the opacity given at the BeginLayer() call. More...
 
virtual void PushState ()=0
 Push the current state of the context (eg. More...
 
virtual void PopState ()=0
 Sets current state of the context to the state saved by a preceding call to PushState() and removes that state from the stack of saved states. More...
 
virtual void Flush ()
 Make sure that the current content of this context is immediately visible. More...
 
Getting/setting parameters
virtual void * GetNativeContext ()=0
 Returns the native context (CGContextRef for Core Graphics, Graphics pointer for GDIPlus and cairo_t pointer for cairo). More...
 
virtual bool SetAntialiasMode (wxAntialiasMode antialias)=0
 Sets the antialiasing mode, returns true if it supported. More...
 
virtual wxAntialiasMode GetAntialiasMode () const
 Returns the current shape antialiasing mode. More...
 
virtual bool SetInterpolationQuality (wxInterpolationQuality interpolation)=0
 Sets the interpolation quality, returns true if it is supported. More...
 
virtual wxInterpolationQuality GetInterpolationQuality () const
 Returns the current interpolation quality. More...
 
virtual bool SetCompositionMode (wxCompositionMode op)=0
 Sets the compositing operator, returns true if it supported. More...
 
virtual wxCompositionMode GetCompositionMode () const
 Returns the current compositing operator. More...
 
void GetSize (wxDouble *width, wxDouble *height) const
 Returns the size of the graphics context in device coordinates. More...
 
virtual void GetDPI (wxDouble *dpiX, wxDouble *dpiY)
 Returns the resolution of the graphics context in device points per inch. More...
 
Offset management
virtual bool ShouldOffset () const
 Helper to determine if a 0.5 offset should be applied for the drawing operation. More...
 
virtual void EnableOffset (bool enable=true)
 Indicates whether the context should try to offset for pixel boundaries. More...
 
void DisableOffset ()
 Helper to determine if a 0.5 offset should be applied for the drawing operation. More...
 
bool OffsetEnabled ()
 Helper to determine if a 0.5 offset should be applied for the drawing operation. More...
 
- Public Member Functions inherited from wxGraphicsObject
wxGraphicsRendererGetRenderer () const
 Returns the renderer that was used to create this instance, or NULL if it has not been initialized yet. More...
 
bool IsNull () const
 
- Public Member Functions inherited from wxObject
 wxObject ()
 Default ctor; initializes to NULL the internal reference data. More...
 
 wxObject (const wxObject &other)
 Copy ctor. More...
 
virtual ~wxObject ()
 Destructor. More...
 
virtual wxClassInfoGetClassInfo () const
 This virtual function is redefined for every class that requires run-time type information, when using the wxDECLARE_CLASS macro (or similar). More...
 
wxObjectRefDataGetRefData () const
 Returns the wxObject::m_refData pointer, i.e. the data referenced by this object. More...
 
bool IsKindOf (const wxClassInfo *info) const
 Determines whether this class is a subclass of (or the same class as) the given class. More...
 
bool IsSameAs (const wxObject &obj) const
 Returns true if this object has the same data pointer as obj. More...
 
void Ref (const wxObject &clone)
 Makes this object refer to the data in clone. More...
 
void SetRefData (wxObjectRefData *data)
 Sets the wxObject::m_refData pointer. More...
 
void UnRef ()
 Decrements the reference count in the associated data, and if it is zero, deletes the data. More...
 
void UnShare ()
 This is the same of AllocExclusive() but this method is public. More...
 
void operator delete (void *buf)
 The delete operator is defined for debugging versions of the library only, when the identifier WXDEBUG is defined. More...
 
void * operator new (size_t size, const wxString &filename=NULL, int lineNum=0)
 The new operator is defined for debugging versions of the library only, when the identifier WXDEBUG is defined. More...
 

Static Public Member Functions

Creating a context
static wxGraphicsContextCreate (wxWindow *window)
 Creates a wxGraphicsContext from a wxWindow. More...
 
static wxGraphicsContextCreate (const wxWindowDC &windowDC)
 Creates a wxGraphicsContext from a wxWindowDC. More...
 
static wxGraphicsContextCreate (const wxMemoryDC &memoryDC)
 Creates a wxGraphicsContext from a wxMemoryDC. More...
 
static wxGraphicsContextCreate (const wxPrinterDC &printerDC)
 Creates a wxGraphicsContext from a wxPrinterDC. More...
 
static wxGraphicsContextCreate (const wxEnhMetaFileDC &metaFileDC)
 Creates a wxGraphicsContext from a wxEnhMetaFileDC. More...
 
static wxGraphicsContextCreate (wxImage &image)
 Creates a wxGraphicsContext associated with a wxImage. More...
 
static wxGraphicsContextCreateFromNative (void *context)
 Creates a wxGraphicsContext from a native context. More...
 
static wxGraphicsContextCreateFromNativeWindow (void *window)
 Creates a wxGraphicsContext from a native window. More...
 
static wxGraphicsContextCreate ()
 Create a lightweight context that can be used only for measuring text. More...
 

Additional Inherited Members

- Protected Member Functions inherited from wxObject
void AllocExclusive ()
 Ensure that this object's data is not shared with any other object. More...
 
virtual wxObjectRefDataCreateRefData () const
 Creates a new instance of the wxObjectRefData-derived class specific to this object and returns it. More...
 
virtual wxObjectRefDataCloneRefData (const wxObjectRefData *data) const
 Creates a new instance of the wxObjectRefData-derived class specific to this object and initializes it copying data. More...
 
- Protected Attributes inherited from wxObject
wxObjectRefDatam_refData
 Pointer to an object which is the object's reference-counted data. More...
 

Member Function Documentation

virtual void wxGraphicsContext::BeginLayer ( wxDouble  opacity)
pure virtual

All rendering will be done into a fully transparent temporary context.

Layers can be nested by making balanced calls to BeginLayer()/EndLayer().

virtual void wxGraphicsContext::Clip ( const wxRegion region)
pure virtual

Sets the clipping region to the intersection of the given region and the previously set clipping region.

The clipping region is an area to which drawing is restricted.

Remarks
  • Clipping region should be given in logical coordinates.
  • Calling this function can only make the clipping region smaller, never larger.
  • You need to call ResetClip() first if you want to set the clipping region exactly to the region specified.
  • If resulting clipping region is empty, then all drawing upon the context is clipped out (all changes made by drawing operations are masked out).
virtual void wxGraphicsContext::Clip ( wxDouble  x,
wxDouble  y,
wxDouble  w,
wxDouble  h 
)
pure virtual

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

virtual void wxGraphicsContext::ConcatTransform ( const wxGraphicsMatrix matrix)
pure virtual

Concatenates the passed in transform with the current transform of this context.

static wxGraphicsContext* wxGraphicsContext::Create ( wxWindow window)
static
static wxGraphicsContext* wxGraphicsContext::Create ( const wxWindowDC windowDC)
static
static wxGraphicsContext* wxGraphicsContext::Create ( const wxMemoryDC memoryDC)
static
static wxGraphicsContext* wxGraphicsContext::Create ( const wxPrinterDC printerDC)
static

Creates a wxGraphicsContext from a wxPrinterDC.

Under GTK+, this will only work when using the GtkPrint printing backend which is available since GTK+ 2.10.

See also
wxGraphicsRenderer::CreateContext(), Printing Under Unix (GTK+)
static wxGraphicsContext* wxGraphicsContext::Create ( const wxEnhMetaFileDC &  metaFileDC)
static

Creates a wxGraphicsContext from a wxEnhMetaFileDC.

This function, as wxEnhMetaFileDC class itself, is only available only under MSW.

See also
wxGraphicsRenderer::CreateContext()
static wxGraphicsContext* wxGraphicsContext::Create ( wxImage image)
static

Creates a wxGraphicsContext associated with a wxImage.

The image specifies the size of the context as well as whether alpha is supported (if wxImage::HasAlpha()) or not and the initial contents of the context. The image object must have a life time greater than that of the new context as the context copies its contents back to the image when it is destroyed.

Since
2.9.3
static wxGraphicsContext* wxGraphicsContext::Create ( )
static

Create a lightweight context that can be used only for measuring text.

virtual wxGraphicsBitmap wxGraphicsContext::CreateBitmap ( const wxBitmap bitmap)
pure virtual

Creates wxGraphicsBitmap from an existing wxBitmap.

Returns an invalid wxNullGraphicsBitmap on failure.

virtual wxGraphicsBitmap wxGraphicsContext::CreateBitmapFromImage ( const wxImage image)
virtual

Creates wxGraphicsBitmap from an existing wxImage.

This method is more efficient than converting wxImage to wxBitmap first and then calling CreateBitmap() but otherwise has the same effect.

Returns an invalid wxNullGraphicsBitmap on failure.

Since
2.9.3
virtual wxGraphicsBrush wxGraphicsContext::CreateBrush ( const wxBrush brush) const
virtual

Creates a native brush from a wxBrush.

virtual wxGraphicsFont wxGraphicsContext::CreateFont ( const wxFont font,
const wxColour col = *wxBLACK 
) const
virtual

Creates a native graphics font from a wxFont and a text colour.

virtual wxGraphicsFont wxGraphicsContext::CreateFont ( double  sizeInPixels,
const wxString facename,
int  flags = wxFONTFLAG_DEFAULT,
const wxColour col = *wxBLACK 
) const
virtual

Creates a font object with the specified attributes.

The use of overload taking wxFont is preferred, see wxGraphicsRenderer::CreateFont() for more details.

Since
2.9.3
static wxGraphicsContext* wxGraphicsContext::CreateFromNative ( void *  context)
static

Creates a wxGraphicsContext from a native context.

This native context must be a CGContextRef for Core Graphics, a Graphics pointer for GDIPlus, or a cairo_t pointer for cairo.

See also
wxGraphicsRenderer::CreateContextFromNativeContext()
static wxGraphicsContext* wxGraphicsContext::CreateFromNativeWindow ( void *  window)
static
wxGraphicsBrush wxGraphicsContext::CreateLinearGradientBrush ( wxDouble  x1,
wxDouble  y1,
wxDouble  x2,
wxDouble  y2,
const wxColour c1,
const wxColour c2 
) const

Creates a native brush with a linear gradient.

The brush starts at (x1, y1) and ends at (x2, y2). Either just the start and end gradient colours (c1 and c2) or full set of gradient stops can be specified.

The version taking wxGraphicsGradientStops is new in wxWidgets 2.9.1.

wxGraphicsBrush wxGraphicsContext::CreateLinearGradientBrush ( wxDouble  x1,
wxDouble  y1,
wxDouble  x2,
wxDouble  y2,
const wxGraphicsGradientStops stops 
) const

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

virtual wxGraphicsMatrix wxGraphicsContext::CreateMatrix ( wxDouble  a = 1.0,
wxDouble  b = 0.0,
wxDouble  c = 0.0,
wxDouble  d = 1.0,
wxDouble  tx = 0.0,
wxDouble  ty = 0.0 
) const
virtual

Creates a native affine transformation matrix from the passed in values.

The default parameters result in an identity matrix.

wxGraphicsMatrix wxGraphicsContext::CreateMatrix ( const wxAffineMatrix2DBase mat) const

Creates a native affine transformation matrix from the passed generic one.

Since
2.9.4
wxGraphicsPath wxGraphicsContext::CreatePath ( ) const

Creates a native graphics path which is initially empty.

virtual wxGraphicsPen wxGraphicsContext::CreatePen ( const wxPen pen) const
virtual

Creates a native pen from a wxPen.

virtual wxGraphicsBrush wxGraphicsContext::CreateRadialGradientBrush ( wxDouble  xo,
wxDouble  yo,
wxDouble  xc,
wxDouble  yc,
wxDouble  radius,
const wxColour oColor,
const wxColour cColor 
) const
virtual

Creates a native brush with a radial gradient.

The brush originates at (xo, yc) and ends on a circle around (xc, yc) with the given radius.

The gradient may be specified either by its start and end colours oColor and cColor or by a full set of gradient stops.

The version taking wxGraphicsGradientStops is new in wxWidgets 2.9.1.

virtual wxGraphicsBrush wxGraphicsContext::CreateRadialGradientBrush ( wxDouble  xo,
wxDouble  yo,
wxDouble  xc,
wxDouble  yc,
wxDouble  radius,
const wxGraphicsGradientStops stops 
)
pure virtual

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

virtual wxGraphicsBitmap wxGraphicsContext::CreateSubBitmap ( const wxGraphicsBitmap bitmap,
wxDouble  x,
wxDouble  y,
wxDouble  w,
wxDouble  h 
)
pure virtual

Extracts a sub-bitmap from an existing bitmap.

void wxGraphicsContext::DisableOffset ( )

Helper to determine if a 0.5 offset should be applied for the drawing operation.

virtual void wxGraphicsContext::DrawBitmap ( const wxGraphicsBitmap bmp,
wxDouble  x,
wxDouble  y,
wxDouble  w,
wxDouble  h 
)
pure virtual

Draws the bitmap.

In case of a mono bitmap, this is treated as a mask and the current brushed is used for filling.

virtual void wxGraphicsContext::DrawBitmap ( const wxBitmap bmp,
wxDouble  x,
wxDouble  y,
wxDouble  w,
wxDouble  h 
)
pure virtual

This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.

virtual void wxGraphicsContext::DrawEllipse ( wxDouble  x,
wxDouble  y,
wxDouble  w,
wxDouble  h 
)
virtual

Draws an ellipse.

virtual void wxGraphicsContext::DrawIcon ( const wxIcon icon,
wxDouble  x,
wxDouble  y,
wxDouble  w,
wxDouble  h 
)
pure virtual

Draws the icon.

virtual void wxGraphicsContext::DrawLines ( size_t  n,
const wxPoint2DDouble points,
wxPolygonFillMode  fillStyle = wxODDEVEN_RULE 
)
virtual

Draws a polygon.

virtual void wxGraphicsContext::DrawPath ( const wxGraphicsPath path,
wxPolygonFillMode  fillStyle = wxODDEVEN_RULE 
)
virtual

Draws the path by first filling and then stroking.

virtual void wxGraphicsContext::DrawRectangle ( wxDouble  x,
wxDouble  y,
wxDouble  w,
wxDouble  h 
)
virtual

Draws a rectangle.

virtual void wxGraphicsContext::DrawRoundedRectangle ( wxDouble  x,
wxDouble  y,
wxDouble  w,
wxDouble  h,
wxDouble  radius 
)
virtual

Draws a rounded rectangle.

void wxGraphicsContext::DrawText ( const wxString str,
wxDouble  x,
wxDouble  y 
)

Draws text at the defined position.

void wxGraphicsContext::DrawText ( const wxString str,
wxDouble  x,
wxDouble  y,
wxDouble  angle 
)

Draws text at the defined position.

Parameters
strThe text to draw.
xThe x coordinate position to draw the text at.
yThe y coordinate position to draw the text at.
angleThe angle relative to the (default) horizontal direction to draw the string.
void wxGraphicsContext::DrawText ( const wxString str,
wxDouble  x,
wxDouble  y,
const wxGraphicsBrush backgroundBrush 
)

Draws text at the defined position.

Parameters
strThe text to draw.
xThe x coordinate position to draw the text at.
yThe y coordinate position to draw the text at.
backgroundBrushBrush to fill the text with.
void wxGraphicsContext::DrawText ( const wxString str,
wxDouble  x,
wxDouble  y,
wxDouble  angle,
const wxGraphicsBrush backgroundBrush 
)

Draws text at the defined position.

Parameters
strThe text to draw.
xThe x coordinate position to draw the text at.
yThe y coordinate position to draw the text at.
angleThe angle relative to the (default) horizontal direction to draw the string.
backgroundBrushBrush to fill the text with.
virtual void wxGraphicsContext::EnableOffset ( bool  enable = true)
virtual

Indicates whether the context should try to offset for pixel boundaries.

This only makes sense on bitmap devices like screen. By default this is turned off.

virtual void wxGraphicsContext::EndDoc ( )
virtual

Done with that document (relevant only for printing / pdf etc.)

virtual void wxGraphicsContext::EndLayer ( )
pure virtual

Composites back the drawings into the context with the opacity given at the BeginLayer() call.

virtual void wxGraphicsContext::EndPage ( )
virtual

Ends the current page (relevant only for printing / pdf etc.)

virtual void wxGraphicsContext::FillPath ( const wxGraphicsPath path,
wxPolygonFillMode  fillStyle = wxODDEVEN_RULE 
)
pure virtual

Fills the path with the current brush.

virtual void wxGraphicsContext::Flush ( )
virtual

Make sure that the current content of this context is immediately visible.

virtual wxAntialiasMode wxGraphicsContext::GetAntialiasMode ( ) const
virtual

Returns the current shape antialiasing mode.

virtual wxCompositionMode wxGraphicsContext::GetCompositionMode ( ) const
virtual

Returns the current compositing operator.

virtual void wxGraphicsContext::GetDPI ( wxDouble dpiX,
wxDouble dpiY 
)
virtual

Returns the resolution of the graphics context in device points per inch.

virtual wxInterpolationQuality wxGraphicsContext::GetInterpolationQuality ( ) const
virtual

Returns the current interpolation quality.

virtual void* wxGraphicsContext::GetNativeContext ( )
pure virtual

Returns the native context (CGContextRef for Core Graphics, Graphics pointer for GDIPlus and cairo_t pointer for cairo).

virtual void wxGraphicsContext::GetPartialTextExtents ( const wxString text,
wxArrayDouble widths 
) const
pure virtual

Fills the widths array with the widths from the beginning of text to the corresponding character of text.

void wxGraphicsContext::GetSize ( wxDouble width,
wxDouble height 
) const

Returns the size of the graphics context in device coordinates.

virtual void wxGraphicsContext::GetTextExtent ( const wxString text,
wxDouble width,
wxDouble height,
wxDouble descent,
wxDouble externalLeading 
) const
pure virtual

Gets the dimensions of the string using the currently selected font.

Parameters
textThe text string to measure.
widthVariable to store the total calculated width of the text.
heightVariable to store the total calculated height of the text.
descentVariable to store the dimension from the baseline of the font to the bottom of the descender.
externalLeadingAny extra vertical space added to the font by the font designer (usually is zero).
virtual wxGraphicsMatrix wxGraphicsContext::GetTransform ( ) const
pure virtual

Gets the current transformation matrix of this context.

bool wxGraphicsContext::OffsetEnabled ( )

Helper to determine if a 0.5 offset should be applied for the drawing operation.

virtual void wxGraphicsContext::PopState ( )
pure virtual

Sets current state of the context to the state saved by a preceding call to PushState() and removes that state from the stack of saved states.

See also
PushState()
virtual void wxGraphicsContext::PushState ( )
pure virtual

Push the current state of the context (eg.

transformation matrix) on a stack. Multiple balanced calls to PushState() and PopState() can be nested.

See also
PopState()
virtual void wxGraphicsContext::ResetClip ( )
pure virtual

Resets the clipping to original shape.

virtual void wxGraphicsContext::Rotate ( wxDouble  angle)
pure virtual

Rotates the current transformation matrix (in radians).

virtual void wxGraphicsContext::Scale ( wxDouble  xScale,
wxDouble  yScale 
)
pure virtual

Scales the current transformation matrix.

virtual bool wxGraphicsContext::SetAntialiasMode ( wxAntialiasMode  antialias)
pure virtual

Sets the antialiasing mode, returns true if it supported.

void wxGraphicsContext::SetBrush ( const wxBrush brush)

Sets the brush for filling paths.

virtual void wxGraphicsContext::SetBrush ( const wxGraphicsBrush brush)
virtual

Sets the brush for filling paths.

virtual bool wxGraphicsContext::SetCompositionMode ( wxCompositionMode  op)
pure virtual

Sets the compositing operator, returns true if it supported.

void wxGraphicsContext::SetFont ( const wxFont font,
const wxColour colour 
)

Sets the font for drawing text.

virtual void wxGraphicsContext::SetFont ( const wxGraphicsFont font)
virtual

Sets the font for drawing text.

virtual bool wxGraphicsContext::SetInterpolationQuality ( wxInterpolationQuality  interpolation)
pure virtual

Sets the interpolation quality, returns true if it is supported.

Remarks
Not implemented in Cairo backend currently.
void wxGraphicsContext::SetPen ( const wxPen pen)

Sets the pen used for stroking.

virtual void wxGraphicsContext::SetPen ( const wxGraphicsPen pen)
virtual

Sets the pen used for stroking.

virtual void wxGraphicsContext::SetTransform ( const wxGraphicsMatrix matrix)
pure virtual

Sets the current transformation matrix of this context.

virtual bool wxGraphicsContext::ShouldOffset ( ) const
virtual

Helper to determine if a 0.5 offset should be applied for the drawing operation.

virtual bool wxGraphicsContext::StartDoc ( const wxString message)
virtual

Begin a new document (relevant only for printing / pdf etc.) If there is a progress dialog, message will be shown.

virtual void wxGraphicsContext::StartPage ( wxDouble  width = 0,
wxDouble  height = 0 
)
virtual

Opens a new page (relevant only for printing / pdf etc.) with the given size in points.

(If both are null the default page size will be used.)

virtual void wxGraphicsContext::StrokeLine ( wxDouble  x1,
wxDouble  y1,
wxDouble  x2,
wxDouble  y2 
)
virtual

Strokes a single line.

virtual void wxGraphicsContext::StrokeLines ( size_t  n,
const wxPoint2DDouble beginPoints,
const wxPoint2DDouble endPoints 
)
virtual

Stroke disconnected lines from begin to end points, fastest method available for this purpose.

virtual void wxGraphicsContext::StrokeLines ( size_t  n,
const wxPoint2DDouble points 
)
virtual

Stroke lines connecting all the points.

Unlike the other overload of this function, this method draws a single polyline and not a number of disconnected lines.

virtual void wxGraphicsContext::StrokePath ( const wxGraphicsPath path)
pure virtual

Strokes along a path with the current pen.

virtual void wxGraphicsContext::Translate ( wxDouble  dx,
wxDouble  dy 
)
pure virtual

Translates the current transformation matrix.