Version: 3.0.2
wxScreenDC Class Reference

#include <wx/dcscreen.h>

+ Inheritance diagram for wxScreenDC:

Detailed Description

A wxScreenDC can be used to paint on the screen.

This should normally be constructed as a temporary stack object; don't store a wxScreenDC object.

Library:  wxCore
Category:  Device Contexts
See Also
wxDC, wxMemoryDC, wxPaintDC, wxClientDC, wxWindowDC

Public Member Functions

 wxScreenDC ()
 Constructor.
 
- Public Member Functions inherited from wxDC
void CopyAttributes (const wxDC &dc)
 Copy attributes from another DC.
 
int GetDepth () const
 Returns the depth (number of bits/pixel) of this DC.
 
wxPoint GetDeviceOrigin () const
 Returns the current device origin.
 
wxRasterOperationMode GetLogicalFunction () const
 Gets the current logical function.
 
wxMappingMode GetMapMode () const
 Gets the current mapping mode for the device context.
 
bool GetPixel (wxCoord x, wxCoord y, wxColour *colour) const
 Gets in colour the colour at the specified location.
 
wxSize GetPPI () const
 Returns the resolution of the device in pixels per inch.
 
void GetSize (wxCoord *width, wxCoord *height) const
 Gets the horizontal and vertical extent of this device context in device units.
 
wxSize GetSize () const
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void GetSizeMM (wxCoord *width, wxCoord *height) const
 Returns the horizontal and vertical resolution in millimetres.
 
wxSize GetSizeMM () const
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void GetUserScale (double *x, double *y) const
 Gets the current user scale factor.
 
bool IsOk () const
 Returns true if the DC is ok to use.
 
void SetAxisOrientation (bool xLeftRight, bool yBottomUp)
 Sets the x and y axis orientation (i.e. the direction from lowest to highest values on the axis).
 
void SetDeviceOrigin (wxCoord x, wxCoord y)
 Sets the device origin (i.e. the origin in pixels after scaling has been applied).
 
void SetLogicalFunction (wxRasterOperationMode function)
 Sets the current logical function for the device context.
 
void SetMapMode (wxMappingMode mode)
 The mapping mode of the device context defines the unit of measurement used to convert logical units to device units.
 
void SetPalette (const wxPalette &palette)
 If this is a window DC or memory DC, assigns the given palette to the window or bitmap associated with the DC.
 
void SetUserScale (double xScale, double yScale)
 Sets the user scaling factor, useful for applications which require 'zooming'.
 
void * GetHandle () const
 Returns a value that can be used as a handle to the native drawing context, if this wxDC has something that could be thought of in that way.
 
wxBitmap GetAsBitmap (const wxRect *subrect=NULL) const
 If supported by the platform and the type of DC, fetch the contents of the DC, or a subset of it, as a bitmap.
 
void SetLogicalScale (double x, double y)
 
void GetLogicalScale (double *x, double *y) const
 
void SetLogicalOrigin (wxCoord x, wxCoord y)
 
void GetLogicalOrigin (wxCoord *x, wxCoord *y) const
 
wxPoint GetLogicalOrigin () const
 
wxCoord DeviceToLogicalX (wxCoord x) const
 Convert device X coordinate to logical coordinate, using the current mapping mode, user scale factor, device origin and axis orientation.
 
wxCoord DeviceToLogicalXRel (wxCoord x) const
 Convert device X coordinate to relative logical coordinate, using the current mapping mode and user scale factor but ignoring the axis orientation.
 
wxCoord DeviceToLogicalY (wxCoord y) const
 Converts device Y coordinate to logical coordinate, using the current mapping mode, user scale factor, device origin and axis orientation.
 
wxCoord DeviceToLogicalYRel (wxCoord y) const
 Convert device Y coordinate to relative logical coordinate, using the current mapping mode and user scale factor but ignoring the axis orientation.
 
wxCoord LogicalToDeviceX (wxCoord x) const
 Converts logical X coordinate to device coordinate, using the current mapping mode, user scale factor, device origin and axis orientation.
 
wxCoord LogicalToDeviceXRel (wxCoord x) const
 Converts logical X coordinate to relative device coordinate, using the current mapping mode and user scale factor but ignoring the axis orientation.
 
wxCoord LogicalToDeviceY (wxCoord y) const
 Converts logical Y coordinate to device coordinate, using the current mapping mode, user scale factor, device origin and axis orientation.
 
wxCoord LogicalToDeviceYRel (wxCoord y) const
 Converts logical Y coordinate to relative device coordinate, using the current mapping mode and user scale factor but ignoring the axis orientation.
 
void Clear ()
 Clears the device context using the current background brush.
 
void DrawArc (wxCoord xStart, wxCoord yStart, wxCoord xEnd, wxCoord yEnd, wxCoord xc, wxCoord yc)
 Draws an arc from the given start to the given end point.
 
void DrawArc (const wxPoint &ptStart, const wxPoint &ptEnd, const wxPoint &centre)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void DrawBitmap (const wxBitmap &bitmap, wxCoord x, wxCoord y, bool useMask=false)
 Draw a bitmap on the device context at the specified point.
 
void DrawBitmap (const wxBitmap &bmp, const wxPoint &pt, bool useMask=false)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void DrawCheckMark (wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 Draws a check mark inside the given rectangle.
 
void DrawCheckMark (const wxRect &rect)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void DrawCircle (wxCoord x, wxCoord y, wxCoord radius)
 Draws a circle with the given centre and radius.
 
void DrawCircle (const wxPoint &pt, wxCoord radius)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void DrawEllipse (wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 Draws an ellipse contained in the rectangle specified either with the given top left corner and the given size or directly.
 
void DrawEllipse (const wxPoint &pt, const wxSize &size)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void DrawEllipse (const wxRect &rect)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void DrawEllipticArc (wxCoord x, wxCoord y, wxCoord width, wxCoord height, double start, double end)
 Draws an arc of an ellipse.
 
void DrawEllipticArc (const wxPoint &pt, const wxSize &sz, double sa, double ea)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void DrawIcon (const wxIcon &icon, wxCoord x, wxCoord y)
 Draw an icon on the display (does nothing if the device context is PostScript).
 
void DrawIcon (const wxIcon &icon, const wxPoint &pt)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void DrawLabel (const wxString &text, const wxBitmap &bitmap, const wxRect &rect, int alignment=wxALIGN_LEFT|wxALIGN_TOP, int indexAccel=-1, wxRect *rectBounding=NULL)
 Draw optional bitmap and the text into the given rectangle and aligns it as specified by alignment parameter; it also will emphasize the character with the given index if it is != -1 and return the bounding rectangle if required.
 
void DrawLabel (const wxString &text, const wxRect &rect, int alignment=wxALIGN_LEFT|wxALIGN_TOP, int indexAccel=-1)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void DrawLine (wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2)
 Draws a line from the first point to the second.
 
void DrawLine (const wxPoint &pt1, const wxPoint &pt2)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void DrawLines (int n, const wxPoint points[], wxCoord xoffset=0, wxCoord yoffset=0)
 Draws lines using an array of points of size n adding the optional offset coordinate.
 
void DrawLines (const wxPointList *points, wxCoord xoffset=0, wxCoord yoffset=0)
 This method uses a list of wxPoints, adding the optional offset coordinate.
 
void DrawPoint (wxCoord x, wxCoord y)
 Draws a point using the color of the current pen.
 
void DrawPoint (const wxPoint &pt)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void DrawPolygon (int n, const wxPoint points[], wxCoord xoffset=0, wxCoord yoffset=0, wxPolygonFillMode fill_style=wxODDEVEN_RULE)
 Draws a filled polygon using an array of points of size n, adding the optional offset coordinate.
 
void DrawPolygon (const wxPointList *points, wxCoord xoffset=0, wxCoord yoffset=0, wxPolygonFillMode fill_style=wxODDEVEN_RULE)
 This method draws a filled polygon using a list of wxPoints, adding the optional offset coordinate.
 
void DrawPolyPolygon (int n, const int count[], const wxPoint points[], wxCoord xoffset=0, wxCoord yoffset=0, wxPolygonFillMode fill_style=wxODDEVEN_RULE)
 Draws two or more filled polygons using an array of points, adding the optional offset coordinates.
 
void DrawRectangle (wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 Draws a rectangle with the given top left corner, and with the given size.
 
void DrawRectangle (const wxPoint &pt, const wxSize &sz)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void DrawRectangle (const wxRect &rect)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void DrawRotatedText (const wxString &text, wxCoord x, wxCoord y, double angle)
 Draws the text rotated by angle degrees (positive angles are counterclockwise; the full angle is 360 degrees).
 
void DrawRotatedText (const wxString &text, const wxPoint &point, double angle)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void DrawRoundedRectangle (wxCoord x, wxCoord y, wxCoord width, wxCoord height, double radius)
 Draws a rectangle with the given top left corner, and with the given size.
 
void DrawRoundedRectangle (const wxPoint &pt, const wxSize &sz, double radius)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void DrawRoundedRectangle (const wxRect &rect, double radius)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void DrawSpline (int n, const wxPoint points[])
 Draws a spline between all given points using the current pen.
 
void DrawSpline (const wxPointList *points)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void DrawSpline (wxCoord x1, wxCoord y1, wxCoord x2, wxCoord y2, wxCoord x3, wxCoord y3)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void DrawText (const wxString &text, wxCoord x, wxCoord y)
 Draws a text string at the specified point, using the current text font, and the current text foreground and background colours.
 
void DrawText (const wxString &text, const wxPoint &pt)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void GradientFillConcentric (const wxRect &rect, const wxColour &initialColour, const wxColour &destColour)
 Fill the area specified by rect with a radial gradient, starting from initialColour at the centre of the circle and fading to destColour on the circle outside.
 
void GradientFillConcentric (const wxRect &rect, const wxColour &initialColour, const wxColour &destColour, const wxPoint &circleCenter)
 Fill the area specified by rect with a radial gradient, starting from initialColour at the centre of the circle and fading to destColour on the circle outside.
 
void GradientFillLinear (const wxRect &rect, const wxColour &initialColour, const wxColour &destColour, wxDirection nDirection=wxRIGHT)
 Fill the area specified by rect with a linear gradient, starting from initialColour and eventually fading to destColour.
 
bool FloodFill (wxCoord x, wxCoord y, const wxColour &colour, wxFloodFillStyle style=wxFLOOD_SURFACE)
 Flood fills the device context starting from the given point, using the current brush colour, and using a style:
 
bool FloodFill (const wxPoint &pt, const wxColour &col, wxFloodFillStyle style=wxFLOOD_SURFACE)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void CrossHair (wxCoord x, wxCoord y)
 Displays a cross hair using the current pen.
 
void CrossHair (const wxPoint &pt)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void DestroyClippingRegion ()
 Destroys the current clipping region so that none of the DC is clipped.
 
void GetClippingBox (wxCoord *x, wxCoord *y, wxCoord *width, wxCoord *height) const
 Gets the rectangle surrounding the current clipping region.
 
void SetClippingRegion (wxCoord x, wxCoord y, wxCoord width, wxCoord height)
 Sets the clipping region for this device context to the intersection of the given region described by the parameters of this method and the previously set clipping region.
 
void SetClippingRegion (const wxPoint &pt, const wxSize &sz)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void SetClippingRegion (const wxRect &rect)
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
void SetDeviceClippingRegion (const wxRegion &region)
 Sets the clipping region for this device context.
 
wxCoord GetCharHeight () const
 Gets the character height of the currently set font.
 
wxCoord GetCharWidth () const
 Gets the average character width of the currently set font.
 
wxFontMetrics GetFontMetrics () const
 Returns the various font characteristics.
 
void GetMultiLineTextExtent (const wxString &string, wxCoord *w, wxCoord *h, wxCoord *heightLine=NULL, const wxFont *font=NULL) const
 Gets the dimensions of the string using the currently selected font.
 
wxSize GetMultiLineTextExtent (const wxString &string) const
 Gets the dimensions of the string using the currently selected font.
 
bool GetPartialTextExtents (const wxString &text, wxArrayInt &widths) const
 Fills the widths array with the widths from the beginning of text to the corresponding character of text.
 
void GetTextExtent (const wxString &string, wxCoord *w, wxCoord *h, wxCoord *descent=NULL, wxCoord *externalLeading=NULL, const wxFont *font=NULL) const
 Gets the dimensions of the string using the currently selected font.
 
wxSize GetTextExtent (const wxString &string) const
 This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
 
int GetBackgroundMode () const
 Returns the current background mode: wxSOLID or wxTRANSPARENT.
 
const wxFontGetFont () const
 Gets the current font.
 
wxLayoutDirection GetLayoutDirection () const
 Gets the current layout direction of the device context.
 
const wxColourGetTextBackground () const
 Gets the current text background colour.
 
const wxColourGetTextForeground () const
 Gets the current text foreground colour.
 
void SetBackgroundMode (int mode)
 mode may be one of wxSOLID and wxTRANSPARENT.
 
void SetFont (const wxFont &font)
 Sets the current font for the DC.
 
void SetTextBackground (const wxColour &colour)
 Sets the current text background colour for the DC.
 
void SetTextForeground (const wxColour &colour)
 Sets the current text foreground colour for the DC.
 
void SetLayoutDirection (wxLayoutDirection dir)
 Sets the current layout direction for the device context.
 
void CalcBoundingBox (wxCoord x, wxCoord y)
 Adds the specified point to the bounding box which can be retrieved with MinX(), MaxX() and MinY(), MaxY() functions.
 
wxCoord MaxX () const
 Gets the maximum horizontal extent used in drawing commands so far.
 
wxCoord MaxY () const
 Gets the maximum vertical extent used in drawing commands so far.
 
wxCoord MinX () const
 Gets the minimum horizontal extent used in drawing commands so far.
 
wxCoord MinY () const
 Gets the minimum vertical extent used in drawing commands so far.
 
void ResetBoundingBox ()
 Resets the bounding box: after a call to this function, the bounding box doesn't contain anything.
 
bool StartDoc (const wxString &message)
 Starts a document (only relevant when outputting to a printer).
 
void StartPage ()
 Starts a document page (only relevant when outputting to a printer).
 
void EndDoc ()
 Ends a document (only relevant when outputting to a printer).
 
void EndPage ()
 Ends a document page (only relevant when outputting to a printer).
 
bool Blit (wxCoord xdest, wxCoord ydest, wxCoord width, wxCoord height, wxDC *source, wxCoord xsrc, wxCoord ysrc, wxRasterOperationMode logicalFunc=wxCOPY, bool useMask=false, wxCoord xsrcMask=wxDefaultCoord, wxCoord ysrcMask=wxDefaultCoord)
 Copy from a source DC to this DC.
 
bool StretchBlit (wxCoord xdest, wxCoord ydest, wxCoord dstWidth, wxCoord dstHeight, wxDC *source, wxCoord xsrc, wxCoord ysrc, wxCoord srcWidth, wxCoord srcHeight, wxRasterOperationMode logicalFunc=wxCOPY, bool useMask=false, wxCoord xsrcMask=wxDefaultCoord, wxCoord ysrcMask=wxDefaultCoord)
 Copy from a source DC to this DC possibly changing the scale.
 
const wxBrushGetBackground () const
 Gets the brush used for painting the background.
 
const wxBrushGetBrush () const
 Gets the current brush.
 
const wxPenGetPen () const
 Gets the current pen.
 
void SetBackground (const wxBrush &brush)
 Sets the current background brush for the DC.
 
void SetBrush (const wxBrush &brush)
 Sets the current brush for the DC.
 
void SetPen (const wxPen &pen)
 Sets the current pen for the DC.
 
bool CanUseTransformMatrix () const
 Check if the use of transformation matrix is supported by the current system.
 
bool SetTransformMatrix (const wxAffineMatrix2D &matrix)
 Set the transformation matrix.
 
wxAffineMatrix2D GetTransformMatrix () const
 Return the transformation matrix used by this device context.
 
void ResetTransformMatrix ()
 Revert the transformation matrix to identity matrix.
 
bool CanDrawBitmap () const
 Does the DC support drawing bitmaps?
 
bool CanGetTextExtent () const
 Does the DC support calculating the size required to draw text?
 
- Public Member Functions inherited from wxObject
 wxObject ()
 Default ctor; initializes to NULL the internal reference data.
 
 wxObject (const wxObject &other)
 Copy ctor.
 
virtual ~wxObject ()
 Destructor.
 
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).
 
wxObjectRefDataGetRefData () const
 Returns the wxObject::m_refData pointer, i.e. the data referenced by this object.
 
bool IsKindOf (const wxClassInfo *info) const
 Determines whether this class is a subclass of (or the same class as) the given class.
 
bool IsSameAs (const wxObject &obj) const
 Returns true if this object has the same data pointer as obj.
 
void Ref (const wxObject &clone)
 Makes this object refer to the data in clone.
 
void SetRefData (wxObjectRefData *data)
 Sets the wxObject::m_refData pointer.
 
void UnRef ()
 Decrements the reference count in the associated data, and if it is zero, deletes the data.
 
void UnShare ()
 This is the same of AllocExclusive() but this method is public.
 
void operator delete (void *buf)
 The delete operator is defined for debugging versions of the library only, when the identifier WXDEBUG is defined.
 
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.
 

Static Public Member Functions

static bool EndDrawingOnTop ()
 Use this in conjunction with StartDrawingOnTop().
 
static bool StartDrawingOnTop (wxWindow *window)
 Use this in conjunction with EndDrawingOnTop() to ensure that drawing to the screen occurs on top of existing windows.
 
static bool StartDrawingOnTop (wxRect *rect=NULL)
 Use this in conjunction with EndDrawingOnTop() to ensure that drawing to the screen occurs on top of existing windows.
 

Additional Inherited Members

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

Constructor & Destructor Documentation

wxScreenDC::wxScreenDC ( )

Constructor.

Member Function Documentation

static bool wxScreenDC::EndDrawingOnTop ( )
static

Use this in conjunction with StartDrawingOnTop().

This function destroys the temporary window created to implement on-top drawing (X only).

static bool wxScreenDC::StartDrawingOnTop ( wxWindow window)
static

Use this in conjunction with EndDrawingOnTop() to ensure that drawing to the screen occurs on top of existing windows.

Without this, some window systems (such as X) only allow drawing to take place underneath other windows.

This version of StartDrawingOnTop() is used to specify that the area that will be drawn on coincides with the given window. It is recommended that an area of the screen is specified with StartDrawingOnTop(wxRect*) because with large regions, flickering effects are noticeable when destroying the temporary transparent window used to implement this feature.

You might use this function when implementing a drag feature, for example as in the wxSplitterWindow implementation.

Remarks
This function is probably obsolete since the X implementations allow drawing directly on the screen now. However, the fact that this function allows the screen to be refreshed afterwards, may be useful to some applications.
static bool wxScreenDC::StartDrawingOnTop ( wxRect rect = NULL)
static

Use this in conjunction with EndDrawingOnTop() to ensure that drawing to the screen occurs on top of existing windows.

Without this, some window systems (such as X) only allow drawing to take place underneath other windows.

This version of StartDrawingOnTop() is used to specify an area of the screen which is to be drawn on. If NULL is passed, the whole screen is available. It is recommended that an area of the screen is specified with this function rather than with StartDrawingOnTop(wxWindow*), because with large regions, flickering effects are noticeable when destroying the temporary transparent window used to implement this feature.

You might use this function when implementing a drag feature, for example as in the wxSplitterWindow implementation.

Remarks
This function is probably obsolete since the X implementations allow drawing directly on the screen now. However, the fact that this function allows the screen to be refreshed afterwards, may be useful to some applications.