# wx.DC¶

A wx.DC is a “device context” onto which graphics and text can be drawn.

It is intended to represent different output devices and offers a common abstract API for drawing on any of them.

wxWidgets offers an alternative drawing API based on the modern drawing backends GDI+, CoreGraphics and Cairo. See wx.GraphicsContext, wx.GraphicsRenderer and related classes. There is also a wx.GCDC linking the APIs by offering the wx.DC API on top of a wx.GraphicsContext.

wx.DC is an abstract base class and cannot be created directly. Use wx.PaintDC, wx.ClientDC, wx.WindowDC, wx.ScreenDC, wx.MemoryDC or wx.PrinterDC. Notice that device contexts which are associated with windows (i.e. wx.ClientDC, wx.WindowDC and wx.PaintDC) use the window font and colours by default (starting with wxWidgets 2.9.0) but the other device context classes use system-default values so you always must set the appropriate fonts and colours before using them.

In addition to the versions of the methods documented below, there are also versions which accept single wx.Point parameter instead of the two int ones or wx.Point and wx.Size instead of the four int parameters.

Beginning with wxWidgets 2.9.0 the entire wx.DC code has been reorganized. All platform dependent code (actually all drawing code) has been moved into backend classes which derive from a common DCImpl class. The user-visible classes such as wx.ClientDC and wx.PaintDC merely forward all calls to the backend implementation.

## Device and logical units¶

In the wx.DC context there is a distinction between logical units and device units. Device units are the units native to the particular device; e.g. for a screen, a device unit is a pixel. For a printer, the device unit is defined by the resolution of the printer (usually given in DPI: dot-per-inch). All wx.DC functions use instead logical units, unless where explicitly stated. Logical units are arbitrary units mapped to device units using the current mapping mode (see wx.DC.SetMapMode ). This mechanism allows reusing the same code which prints on e.g. a window on the screen to print on e.g. a paper.

## Support for Transparency / Alpha Channel¶

In general wx.DC methods don’t support alpha transparency and the alpha component of wx.Colour is simply ignored and you need to use wx.GraphicsContext for full transparency support. There are, however, a few exceptions: first, under Mac OS X colours with alpha channel are supported in all the normal DC-derived classes as they use wx.GraphicsContext internally. Second, under all platforms wx.SVGFileDC also fully supports alpha channel. In both of these cases the instances of wx.Pen or wx.Brush that are built from wx.Colour use the colour’s alpha values when stroking or filling.

## for Transformation Matrix¶

On some platforms (currently only under MSW and only on Windows NT, i.e. not Windows 9x/ME, systems) wx.DC has support for applying an arbitrary affine transformation matrix to its coordinate system. Call CanUseTransformMatrix to check if this support is available and then call SetTransformMatrix if it is. If the transformation matrix is not supported, SetTransformMatrix always simply returns False and doesn’t do anything.

Todo

Precise definition of default/initial state. Pixelwise definition of operations (e.g. last point of a line not drawn).

## Class Hierarchy¶

Inheritance diagram for class DC:

## Methods Summary¶

 Blit Copy from a source DC to this DC. CalcBoundingBox Adds the specified point to the bounding box which can be retrieved with MinX , MaxX and MinY , MaxY functions. CanDrawBitmap Does the DC support drawing bitmaps? CanGetTextExtent Does the DC support calculating the size required to draw text? CanUseTransformMatrix Check if the use of transformation matrix is supported by the current system. Clear Clears the device context using the current background brush. CopyAttributes Copy attributes from another DC. CrossHair Displays a cross hair using the current pen. DestroyClippingRegion Destroys the current clipping region so that none of the DC is clipped. DeviceToLogicalX Convert device X coordinate to logical coordinate, using the current mapping mode, user scale factor, device origin and axis orientation. DeviceToLogicalXRel Convert device X coordinate to relative logical coordinate, using the current mapping mode and user scale factor but ignoring the axis orientation. DeviceToLogicalY Converts device Y coordinate to logical coordinate, using the current mapping mode, user scale factor, device origin and axis orientation. DeviceToLogicalYRel Convert device Y coordinate to relative logical coordinate, using the current mapping mode and user scale factor but ignoring the axis orientation. DrawArc Draws an arc from the given start to the given end point. DrawBitmap Draw a bitmap on the device context at the specified point. DrawCheckMark Draws a check mark inside the given rectangle. DrawCircle Draws a circle with the given centre and radius. DrawEllipse Draws an ellipse contained in the rectangle specified either with the given top left corner and the given size or directly. DrawEllipseList Draw a list of ellipses as quickly as possible. DrawEllipticArc Draws an arc of an ellipse. DrawIcon Draw an icon on the display (does nothing if the device context is PostScript). DrawLabel 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. DrawLine Draws a line from the first point to the second. DrawLineList Draw a list of lines as quickly as possible. DrawLines This method uses a list of Points, adding the optional offset coordinate. DrawPoint Draws a point using the color of the current pen. DrawPointList Draw a list of points as quickly as possible. DrawPolygon This method draws a filled polygon using a list of Points, adding the optional offset coordinate. DrawPolygonList Draw a list of polygons, each of which is a list of points. DrawRectangle Draws a rectangle with the given top left corner, and with the given size. DrawRectangleList Draw a list of rectangles as quickly as possible. DrawRotatedText Draws the text rotated by angle degrees (positive angles are counterclockwise; the full angle is 360 degrees). DrawRoundedRectangle Draws a rectangle with the given top left corner, and with the given size. DrawSpline This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. DrawText Draws a text string at the specified point, using the current text font, and the current text foreground and background colours. DrawTextList Draw a list of strings using a list of coordinants for positioning each string. EndDoc Ends a document (only relevant when outputting to a printer). EndPage Ends a document page (only relevant when outputting to a printer). FloodFill Flood fills the device context starting from the given point, using the current brush colour, and using a style GetAsBitmap If supported by the platform and the type of DC, fetch the contents of the DC, or a subset of it, as a bitmap. GetBackground Gets the brush used for painting the background. GetBackgroundMode Returns the current background mode: SOLID or TRANSPARENT . GetBoundingBox GetBoundingBox() . (x1,y1, x2,y2) GetBrush Gets the current brush. GetCGContext GetCharHeight Gets the character height of the currently set font. GetCharWidth Gets the average character width of the currently set font. GetClippingBox Gets the rectangle surrounding the current clipping region. GetClippingRect Gets the rectangle surrounding the current clipping region GetDepth Returns the depth (number of bits/pixel) of this DC. GetDeviceOrigin Returns the current device origin. GetFont Gets the current font. GetFontMetrics Returns the various font characteristics. GetGdkDrawable GetHDC GetHandle Returns a value that can be used as a handle to the native drawing context, if this wx.DC has something that could be thought of in that way. GetLayoutDirection Gets the current layout direction of the device context. GetLogicalFunction Gets the current logical function. GetLogicalOrigin Return the coordinates of the logical point (0, 0). GetLogicalScale Return the scale set by the last call to SetLogicalScale . GetMapMode Gets the current mapping mode for the device context. GetFullMultiLineTextExtent Gets the dimensions of the string as it would be drawn. GetMultiLineTextExtent Return the dimensions of the given string’s text extent using the GetPPI Returns the resolution of the device in pixels per inch. GetPartialTextExtents Fills the widths array with the widths from the beginning of text to the corresponding character of text. GetPen Gets the current pen. GetPixel Gets the colour at the specified location on the DC. GetSize This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. GetSizeMM This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. GetTextBackground Gets the current text background colour. GetFullTextExtent Gets the dimensions of the string as it would be drawn. GetTextExtent Return the dimensions of the given string’s text extent using the GetTextForeground Gets the current text foreground colour. GetTransformMatrix Return the transformation matrix used by this device context. GetUserScale Gets the current user scale factor. GradientFillConcentric 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. GradientFillLinear Fill the area specified by rect with a linear gradient, starting from initialColour and eventually fading to destColour. IsOk Returns True if the DC is ok to use. LogicalToDeviceX Converts logical X coordinate to device coordinate, using the current mapping mode, user scale factor, device origin and axis orientation. LogicalToDeviceXRel Converts logical X coordinate to relative device coordinate, using the current mapping mode and user scale factor but ignoring the axis orientation. LogicalToDeviceY Converts logical Y coordinate to device coordinate, using the current mapping mode, user scale factor, device origin and axis orientation. LogicalToDeviceYRel Converts logical Y coordinate to relative device coordinate, using the current mapping mode and user scale factor but ignoring the axis orientation. MaxX Gets the maximum horizontal extent used in drawing commands so far. MaxY Gets the maximum vertical extent used in drawing commands so far. MinX Gets the minimum horizontal extent used in drawing commands so far. MinY Gets the minimum vertical extent used in drawing commands so far. ResetBoundingBox Resets the bounding box: after a call to this function, the bounding box doesn’t contain anything. ResetTransformMatrix Revert the transformation matrix to identity matrix. SetAxisOrientation Sets the x and y axis orientation (i.e. the direction from lowest to highest values on the axis). SetBackground Sets the current background brush for the DC. SetBackgroundMode mode may be one of SOLID and TRANSPARENT . SetBrush Sets the current brush for the DC. SetClippingRegion 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. SetDeviceClippingRegion Sets the clipping region for this device context. SetDeviceOrigin Sets the device origin (i.e. the origin in pixels after scaling has been applied). SetFont Sets the current font for the DC. SetLayoutDirection Sets the current layout direction for the device context. SetLogicalFunction Sets the current logical function for the device context. SetLogicalOrigin Change the offset used for translating wx.DC coordinates. SetLogicalScale Set the scale to use for translating wx.DC coordinates to the physical pixels. SetMapMode The mapping mode of the device context defines the unit of measurement used to convert logical units to device units. SetPalette If this is a window DC or memory DC, assigns the given palette to the window or bitmap associated with the DC. SetPen Sets the current pen for the DC. SetTextBackground Sets the current text background colour for the DC. SetTextForeground Sets the current text foreground colour for the DC. SetTransformMatrix Set the transformation matrix. SetUserScale Sets the user scaling factor, useful for applications which require ‘zooming’. StartDoc Starts a document (only relevant when outputting to a printer). StartPage Starts a document page (only relevant when outputting to a printer). StretchBlit Copy from a source DC to this DC possibly changing the scale. _DrawEllipseList _DrawLineList _DrawPointList _DrawPolygonList _DrawRectangleList _DrawTextList __bool__ __enter__ __exit__ __nonzero__

## Class API¶

class wx.DC(Object)

A DC is a “device context” onto which graphics and text can be drawn.

### Methods¶

Blit(self, xdest, ydest, width, height, source, xsrc, ysrc, logicalFunc=COPY, useMask=False, xsrcMask=DefaultCoord, ysrcMask=DefaultCoord)

Copy from a source DC to this DC.

With this method you can specify the destination coordinates and the size of area to copy which will be the same for both the source and target DCs. If you need to apply scaling while copying, use StretchBlit .

Notice that source DC coordinates xsrc and ysrc are interpreted using the current source DC coordinate system, i.e. the scale, origin position and axis directions are taken into account when transforming them to physical (pixel) coordinates.

Parameters
• xdest (int) – Destination device context x position.

• ydest (int) – Destination device context y position.

• width (int) – Width of source area to be copied.

• height (int) – Height of source area to be copied.

• source (wx.DC) – Source device context.

• xsrc (int) – Source device context x position.

• ysrc (int) – Source device context y position.

• logicalFunc (RasterOperationMode) – Logical function to use, see SetLogicalFunction .

• useMask (bool) – If True, Blit does a transparent blit using the mask that is associated with the bitmap selected into the source device context. The Windows implementation does the following if MaskBlt cannot be used:

• Creates a temporary bitmap and copies the destination area into it.

• Copies the source area into the temporary bitmap using the specified logical function.

• Sets the masked area in the temporary bitmap to wx.BLACK by ANDing the mask bitmap with the temp bitmap with the foreground colour set to wx.WHITE and the bg colour set to wx.BLACK.

• Sets the unmasked area in the destination area to wx.BLACK by ANDing the mask bitmap with the destination area with the foreground colour set to wx.BLACK and the background colour set to wx.WHITE.

• ORs the temporary bitmap with the destination area.

• Deletes the temporary bitmap.

This sequence of operations ensures that the source’s transparent area need not be black, and logical functions are supported.

Note: on Windows, blitting with masks can be speeded up considerably by compiling wxWidgets with the USE_DC_CACHEING option enabled. You can also influence whether MaskBlt or the explicit mask blitting code above is used, by using wx.SystemOptions and setting the no-maskblt option to 1.

• xsrcMask (int) – Source x position on the mask. If both xsrcMask and ysrcMask are -1 , xsrc and ysrc will be assumed for the mask source position. Currently only implemented on Windows.

• ysrcMask (int) – Source y position on the mask. If both xsrcMask and ysrcMask are -1 , xsrc and ysrc will be assumed for the mask source position. Currently only implemented on Windows.

Return type

bool

Note

There is partial support for Blit in wx.PostScriptDC, under X.

CalcBoundingBox(self, x, y)

Adds the specified point to the bounding box which can be retrieved with MinX , MaxX and MinY , MaxY functions.

Parameters
• x (int) –

• y (int) –

CanDrawBitmap(self)

Does the DC support drawing bitmaps?

Return type

bool

CanGetTextExtent(self)

Does the DC support calculating the size required to draw text?

Return type

bool

CanUseTransformMatrix(self)

Check if the use of transformation matrix is supported by the current system.

Currently this function always returns False for non-MSW platforms and may return False for old (Windows 9x/ME) Windows systems. Normally support for the transformation matrix is always available in any relatively recent Windows versions.

Return type

bool

New in version 2.9.2.

Clear(self)

Clears the device context using the current background brush.

CopyAttributes(self, dc)

Copy attributes from another DC.

The copied attributes currently are:

• Font

• Text foreground and background colours

• Background brush

• Layout direction

Parameters

dc (wx.DC) – A valid (i.e. its IsOk must return True) source device context.

CrossHair(self, *args, **kw)

CrossHair (self, x, y)

Displays a cross hair using the current pen.

This is a vertical and horizontal line the height and width of the window, centred on the given point.

Parameters
• x (int) –

• y (int) –

CrossHair (self, pt)

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

Parameters

pt (wx.Point) –

DestroyClippingRegion(self)

Destroys the current clipping region so that none of the DC is clipped.

DeviceToLogicalX(self, x)

Convert device X coordinate to logical coordinate, using the current mapping mode, user scale factor, device origin and axis orientation.

Parameters

x (int) –

Return type

wx.Coord

DeviceToLogicalXRel(self, x)

Convert device X coordinate to relative logical coordinate, using the current mapping mode and user scale factor but ignoring the axis orientation.

Use this for converting a width, for example.

Parameters

x (int) –

Return type

wx.Coord

DeviceToLogicalY(self, y)

Converts device Y coordinate to logical coordinate, using the current mapping mode, user scale factor, device origin and axis orientation.

Parameters

y (int) –

Return type

wx.Coord

DeviceToLogicalYRel(self, y)

Convert device Y coordinate to relative logical coordinate, using the current mapping mode and user scale factor but ignoring the axis orientation.

Use this for converting a height, for example.

Parameters

y (int) –

Return type

wx.Coord

DrawArc(self, *args, **kw)

DrawArc (self, xStart, yStart, xEnd, yEnd, xc, yc)

Draws an arc from the given start to the given end point.

The arc drawn is an arc of the circle centered at ( xc, yc). Its start point is (xStart, yStart) whereas its end point is the point of intersection of the line passing by (xc, yc) and (xEnd, yEnd) with the circle passing by (xStart, yStart).

The arc is drawn in a counter-clockwise direction between the start and the end points.

The current pen is used for the outline and the current brush for filling the shape. Notice that unless the brush is transparent, the lines connecting the centre of the circle to the end points of the arc are drawn as well.

Parameters
• xStart (int) –

• yStart (int) –

• xEnd (int) –

• yEnd (int) –

• xc (int) –

• yc (int) –

Note

DrawEllipticArc has more clear semantics and it is recommended to use it instead of this function.

DrawArc (self, ptStart, ptEnd, centre)

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

Parameters

DrawBitmap(self, *args, **kw)

DrawBitmap (self, bitmap, x, y, useMask=False)

Draw a bitmap on the device context at the specified point.

If transparent is True and the bitmap has a transparency mask, the bitmap will be drawn transparently.

When drawing a mono-bitmap, the current text foreground colour will be used to draw the foreground of the bitmap (all bits set to 1), and the current text background colour to draw the background (all bits set to 0).

Parameters
• bitmap (wx.Bitmap) –

• x (int) –

• y (int) –

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

Parameters

DrawCheckMark(self, *args, **kw)

DrawCheckMark (self, x, y, width, height)

Draws a check mark inside the given rectangle.

Parameters
• x (int) –

• y (int) –

• width (int) –

• height (int) –

DrawCheckMark (self, rect)

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

Parameters

rect (wx.Rect) –

DrawCircle(self, *args, **kw)

Draws a circle with the given centre and radius.

Parameters
• x (int) –

• y (int) –

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

Parameters

DrawEllipse(self, *args, **kw)

DrawEllipse (self, x, y, width, height)

Draws an ellipse contained in the rectangle specified either with the given top left corner and the given size or directly.

The current pen is used for the outline and the current brush for filling the shape.

Parameters
• x (int) –

• y (int) –

• width (int) –

• height (int) –

DrawEllipse (self, pt, size)

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

Parameters

DrawEllipse (self, rect)

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

Parameters

rect (wx.Rect) –

DrawEllipseList(self, ellipses, pens=None, brushes=None)

Draw a list of ellipses as quickly as possible.

Parameters
• ellipses – A sequence of 4-element sequences representing each ellipse to draw, (x,y, w,h).

• pens – If None, then the current pen is used. If a single pen then it will be used for all ellipses. If a list of pens then there should be one for each ellipse in ellipses.

• brushes – A brush or brushes to be used to fill the ellipses, with similar semantics as the pens parameter.

DrawEllipticArc(self, *args, **kw)

DrawEllipticArc (self, x, y, width, height, start, end)

Draws an arc of an ellipse.

The current pen is used for drawing the arc and the current brush is used for drawing the pie.

x and y specify the x and y coordinates of the upper-left corner of the rectangle that contains the ellipse.

width and height specify the width and height of the rectangle that contains the ellipse.

start and end specify the start and end of the arc relative to the three-o’clock position from the center of the rectangle. Angles are specified in degrees with 0 degree angle corresponding to the positive horizontal axis (3 o’clock) direction. Positive values mean counter-clockwise motion. If start is equal to end, a complete ellipse will be drawn.

Notice that unlike DrawArc , this function does not draw the lines to the arc ends, even when using non-transparent brush.

Parameters
• x (int) –

• y (int) –

• width (int) –

• height (int) –

• start (float) –

• end (float) –

DrawEllipticArc (self, pt, sz, sa, ea)

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

Parameters

DrawIcon(self, *args, **kw)

DrawIcon (self, icon, x, y)

Draw an icon on the display (does nothing if the device context is PostScript).

This can be the simplest way of drawing bitmaps on a window.

Parameters
• icon (wx.Icon) –

• x (int) –

• y (int) –

DrawIcon (self, icon, pt)

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

Parameters

DrawLabel(self, *args, **kw)

DrawLabel (self, text, bitmap, rect, alignment=ALIGN_LEFT|ALIGN_TOP, indexAccel=-1)

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.

Parameters
• text (string) –

• bitmap (wx.Bitmap) –

• rect (wx.Rect) –

• alignment (int) –

• indexAccel (int) –

Return type

wx.Rect

DrawLabel (self, text, rect, alignment=ALIGN_LEFT|ALIGN_TOP, indexAccel=-1)

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

Parameters
• text (string) –

• rect (wx.Rect) –

• alignment (int) –

• indexAccel (int) –

DrawLine(self, *args, **kw)

DrawLine (self, x1, y1, x2, y2)

Draws a line from the first point to the second.

The current pen is used for drawing the line. Note that the point (x2, y2) is not part of the line and is not drawn by this function (this is consistent with the behaviour of many other toolkits).

Parameters
• x1 (int) –

• y1 (int) –

• x2 (int) –

• y2 (int) –

DrawLine (self, pt1, pt2)

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

Parameters

DrawLineList(self, lines, pens=None)

Draw a list of lines as quickly as possible.

Parameters
• lines – A sequence of 4-element sequences representing each line to draw, (x1,y1, x2,y2).

• pens – If None, then the current pen is used. If a single pen then it will be used for all lines. If a list of pens then there should be one for each line in lines.

DrawLines(self, points, xoffset=0, yoffset=0)

This method uses a list of Points, adding the optional offset coordinate.

The programmer is responsible for deleting the list of points.

DrawPoint(self, *args, **kw)

DrawPoint (self, x, y)

Draws a point using the color of the current pen.

Note that the other properties of the pen are not used, such as width.

Parameters
• x (int) –

• y (int) –

DrawPoint (self, pt)

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

Parameters

pt (wx.Point) –

DrawPointList(self, points, pens=None)

Draw a list of points as quickly as possible.

Parameters
• points – A sequence of 2-element sequences representing each point to draw, (x,y).

• pens – If None, then the current pen is used. If a single pen then it will be used for all points. If a list of pens then there should be one for each point in points.

DrawPolygon(self, points, xoffset=0, yoffset=0, fill_style=ODDEVEN_RULE)

This method draws a filled polygon using a list of Points, adding the optional offset coordinate.

The first and last points are automatically closed.

The last argument specifies the fill rule: wx.ODDEVEN_RULE (the default) or wx.WINDING_RULE.

The current pen is used for drawing the outline, and the current brush for filling the shape. Using a transparent brush suppresses filling.

The programmer is responsible for deleting the list of points.

DrawPolygonList(self, polygons, pens=None, brushes=None)

Draw a list of polygons, each of which is a list of points.

Parameters
• polygons – A sequence of sequences of sequences. [[(x1,y1),(x2,y2),(x3,y3)…], [(x1,y1),(x2,y2),(x3,y3)…]]

• pens – If None, then the current pen is used. If a single pen then it will be used for all polygons. If a list of pens then there should be one for each polygon.

• brushes – A brush or brushes to be used to fill the polygons, with similar semantics as the pens parameter.

DrawRectangle(self, *args, **kw)

DrawRectangle (self, x, y, width, height)

Draws a rectangle with the given top left corner, and with the given size.

The current pen is used for the outline and the current brush for filling the shape.

Parameters
• x (int) –

• y (int) –

• width (int) –

• height (int) –

DrawRectangle (self, pt, sz)

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

Parameters

DrawRectangle (self, rect)

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

Parameters

rect (wx.Rect) –

DrawRectangleList(self, rectangles, pens=None, brushes=None)

Draw a list of rectangles as quickly as possible.

Parameters
• rectangles – A sequence of 4-element sequences representing each rectangle to draw, (x,y, w,h).

• pens – If None, then the current pen is used. If a single pen then it will be used for all rectangles. If a list of pens then there should be one for each rectangle in rectangles.

• brushes – A brush or brushes to be used to fill the rectagles, with similar semantics as the pens parameter.

DrawRotatedText(self, *args, **kw)

DrawRotatedText (self, text, x, y, angle)

Draws the text rotated by angle degrees (positive angles are counterclockwise; the full angle is 360 degrees).

Parameters
• text (string) –

• x (int) –

• y (int) –

• angle (float) –

Note

Under Win9x only TrueType fonts can be drawn by this function. In particular, a font different from NORMAL_FONT should be used as the latter is not a TrueType font. SWISS_FONT is an example of a font which is.

DrawRotatedText (self, text, point, angle)

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

Parameters
• text (string) –

• point (wx.Point) –

• angle (float) –

DrawRoundedRectangle(self, *args, **kw)

DrawRoundedRectangle (self, x, y, width, height, radius)

Draws a rectangle with the given top left corner, and with the given size.

The corners are quarter-circles using the given radius. The current pen is used for the outline and the current brush for filling the shape.

If radius is positive, the value is assumed to be the radius of the rounded corner. If radius is negative, the absolute value is assumed to be the proportion of the smallest dimension of the rectangle. This means that the corner can be a sensible size relative to the size of the rectangle, and also avoids the strange effects X produces when the corners are too big for the rectangle.

Parameters
• x (int) –

• y (int) –

• width (int) –

• height (int) –

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

Parameters

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

Parameters
• rect (wx.Rect) –

DrawSpline(self, *args, **kw)

DrawSpline (self, points)

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

DrawSpline (self, x1, y1, x2, y2, x3, y3)

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

DrawText(self, *args, **kw)

DrawText (self, text, x, y)

Draws a text string at the specified point, using the current text font, and the current text foreground and background colours.

The coordinates refer to the top-left corner of the rectangle bounding the string. See GetTextExtent for how to get the dimensions of a text string, which can be used to position the text more precisely and DrawLabel if you need to align the string differently.

Starting from wxWidgets 2.9.2 text parameter can be a multi-line string, i.e. contain new line characters, and will be rendered correctly.

Parameters
• text (string) –

• x (int) –

• y (int) –

Note

The current logical function is ignored by this function.

DrawText (self, text, pt)

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

Parameters

DrawTextList(self, textList, coords, foregrounds=None, backgrounds=None)

Draw a list of strings using a list of coordinants for positioning each string.

Parameters
• textList – A list of strings

• coords – A list of (x,y) positions

• foregrounds – A list of wx.Colour objects to use for the foregrounds of the strings.

• backgrounds – A list of wx.Colour objects to use for the backgrounds of the strings.

NOTE: Make sure you set background mode to wx.Solid (DC.SetBackgroundMode)

If you want backgrounds to do anything.

EndDoc(self)

Ends a document (only relevant when outputting to a printer).

EndPage(self)

Ends a document page (only relevant when outputting to a printer).

FloodFill(self, *args, **kw)

FloodFill (self, x, y, colour, style=FLOOD_SURFACE)

Flood fills the device context starting from the given point, using the current brush colour, and using a style:

• wx.FLOOD_SURFACE: The flooding occurs until a colour other than the given colour is encountered.

• wx.FLOOD_BORDER: The area to be flooded is bounded by the given colour.

Currently this method is not implemented in wxOSX and does nothing there.

Parameters
Return type

bool

Returns

False if the operation failed.

Note

The present implementation for non-Windows platforms may fail to find colour borders if the pixels do not match the colour exactly. However the function will still return True.

Note

This method shouldn’t be used with wx.PaintDC under non-Windows platforms as it uses GetPixel internally and this may give wrong results, notably in wxGTK. If you need to flood fill wx.PaintDC, create a temporary wx.MemoryDC, flood fill it and then blit it to, or draw as a bitmap on, wx.PaintDC. See the example of doing this in the drawing sample and wx.BufferedPaintDC class.

FloodFill (self, pt, col, style=FLOOD_SURFACE)

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

Parameters
Return type

bool

GetAsBitmap(self, subrect=None)

If supported by the platform and the type of DC, fetch the contents of the DC, or a subset of it, as a bitmap.

Parameters

subrect (wx.Rect) –

Return type

wx.Bitmap

GetBackground(self)

Gets the brush used for painting the background.

Return type

wx.Brush

GetBackgroundMode(self)

Returns the current background mode: SOLID or TRANSPARENT .

Return type

int

GetBoundingBox(self)

Returns the min and max points used in drawing commands so far.

GetBrush(self)

Gets the current brush.

Return type

wx.Brush

GetCGContext(self)
Return type

wx.UIntPtr

GetCharHeight(self)

Gets the character height of the currently set font.

Return type

wx.Coord

GetCharWidth(self)

Gets the average character width of the currently set font.

Return type

wx.Coord

GetClippingBox(self)

Gets the rectangle surrounding the current clipping region.

Return type

tuple

Returns

( x, y, width, height )

GetClippingRect(self)

Gets the rectangle surrounding the current clipping region

GetDepth(self)

Returns the depth (number of bits/pixel) of this DC.

Return type

int

GetDeviceOrigin(self)

Returns the current device origin.

Return type

wx.Point

GetFont(self)

Gets the current font.

Notice that even although each device context object has some default font after creation, this method would return a wx.NullFont initially and only after calling SetFont a valid font is returned.

Return type

wx.Font

GetFontMetrics(self)

Returns the various font characteristics.

This method allows retrieving some of the font characteristics not returned by GetTextExtent , notably internal leading and average character width.

Currently this method returns correct results only under wxMSW, in the other ports the internal leading will always be 0 and the average character width will be computed as the width of the character ‘x’.

Return type

wx.FontMetrics

New in version 2.9.2.

GetGdkDrawable(self)
Return type

wx.UIntPtr

GetHDC(self)
Return type

long

GetHandle(self)

Returns a value that can be used as a handle to the native drawing context, if this wx.DC has something that could be thought of in that way.

(Not all of them do.)

For example, on Windows the return value is an HDC, on OSX it is a CGContextRef and on wxGTK it will be a GdkDrawable. If the DC is a wx.GCDC then the return value will be the value returned from wx.GraphicsContext.GetNativeContext . A value of None is returned if the DC does not have anything that fits the handle concept.

Return type

wx.UIntPtr

New in version 2.9.5.

GetLayoutDirection(self)

Gets the current layout direction of the device context.

On platforms where RTL layout is supported, the return value will either be Layout_LeftToRight or Layout_RightToLeft . If RTL layout is not supported, the return value will be Layout_Default .

Return type

wx.LayoutDirection

GetLogicalFunction(self)

Gets the current logical function.

Return type

wx.RasterOperationMode

GetLogicalOrigin(self)

Return the coordinates of the logical point (0, 0).

Return type

tuple

Returns

( x, y )

GetLogicalScale(self)

Return the scale set by the last call to SetLogicalScale .

Return type

tuple

Returns

( x, y )

GetMapMode(self)

Gets the current mapping mode for the device context.

Return type

wx.MappingMode

GetFullMultiLineTextExtent(self, string, font=None)

Gets the dimensions of the string as it would be drawn.

The string parameter is the string to measure. The return value is a tuple of integer values consisting of widget, height and heightLine. The heightLine is the the height of a single line.

If the optional parameter font is specified and valid, then it is used for the text extent calculation. Otherwise the currently selected font is.

Note

This function works with both single-line and multi-line strings.

wx.Font, SetFont, GetTextExtent

Parameters
• string (string) –

• font (wx.Font) –

Return type

tuple

Returns

( w, h, heightLine )

GetMultiLineTextExtent(self, st)

Return the dimensions of the given string’s text extent using the currently selected font, taking into account multiple lines if present in the string.

Parameters

st – The string to be measured

Return type

wx.Size

GetPPI(self)

Returns the resolution of the device in pixels per inch.

Return type

wx.Size

GetPartialTextExtents(self, text)

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

The generic version simply builds a running total of the widths of each character using GetTextExtent , however if the various platforms have a native API function that is faster or more accurate than the generic implementation then it should be used instead.

GetPen(self)

Gets the current pen.

Return type

wx.Pen

GetPixel(self, x, y)

Gets the colour at the specified location on the DC.

Return type

wx.Colour

GetSize(self)

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

Return type

wx.Size

GetSizeMM(self)

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

Return type

wx.Size

GetTextBackground(self)

Gets the current text background colour.

Return type

wx.Colour

GetFullTextExtent(self, string, font=None)

Gets the dimensions of the string as it would be drawn.

The string parameter is the string to measure. The return value is a tuple of integer values consisting of widget, height, decent and externalLeading. The descent is the dimension from the baseline of the font to the bottom of the descender, and externalLeading is any extra vertical space added to the font by the font designer (usually is zero).

If the optional parameter font is specified and valid, then it is used for the text extent calculation. Otherwise the currently selected font is.

wx.Font, SetFont, GetMultiLineTextExtent

Parameters
• string (string) –

• font (wx.Font) –

Return type

tuple

Returns

( w, h, descent, externalLeading )

GetTextExtent(self, st)

Return the dimensions of the given string’s text extent using the currently selected font.

Parameters

st – The string to be measured

Return type

wx.Size

GetTextForeground(self)

Gets the current text foreground colour.

Return type

wx.Colour

GetTransformMatrix(self)

Return the transformation matrix used by this device context.

By default the transformation matrix is the identity matrix.

Return type

wx.AffineMatrix2D

New in version 2.9.2.

GetUserScale(self)

Gets the current user scale factor.

GradientFillConcentric(self, *args, **kw)

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.

The circle is placed at the centre of rect.

Parameters

Note

Currently this function is very slow, don’t use it for real-time drawing.

GradientFillConcentric (self, rect, initialColour, destColour, 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.

circleCenter are the relative coordinates of centre of the circle in the specified rect.

Parameters

Note

Currently this function is very slow, don’t use it for real-time drawing.

GradientFillLinear(self, rect, initialColour, destColour, nDirection=RIGHT)

Fill the area specified by rect with a linear gradient, starting from initialColour and eventually fading to destColour.

The nDirection specifies the direction of the colour change, default is to use initialColour on the left part of the rectangle and destColour on the right one.

Parameters

IsOk(self)

Returns True if the DC is ok to use.

Return type

bool

LogicalToDeviceX(self, x)

Converts logical X coordinate to device coordinate, using the current mapping mode, user scale factor, device origin and axis orientation.

Parameters

x (int) –

Return type

wx.Coord

LogicalToDeviceXRel(self, x)

Converts logical X coordinate to relative device coordinate, using the current mapping mode and user scale factor but ignoring the axis orientation.

Use this for converting a width, for example.

Parameters

x (int) –

Return type

wx.Coord

LogicalToDeviceY(self, y)

Converts logical Y coordinate to device coordinate, using the current mapping mode, user scale factor, device origin and axis orientation.

Parameters

y (int) –

Return type

wx.Coord

LogicalToDeviceYRel(self, y)

Converts logical Y coordinate to relative device coordinate, using the current mapping mode and user scale factor but ignoring the axis orientation.

Use this for converting a height, for example.

Parameters

y (int) –

Return type

wx.Coord

MaxX(self)

Gets the maximum horizontal extent used in drawing commands so far.

Return type

wx.Coord

MaxY(self)

Gets the maximum vertical extent used in drawing commands so far.

Return type

wx.Coord

MinX(self)

Gets the minimum horizontal extent used in drawing commands so far.

Return type

wx.Coord

MinY(self)

Gets the minimum vertical extent used in drawing commands so far.

Return type

wx.Coord

ResetBoundingBox(self)

Resets the bounding box: after a call to this function, the bounding box doesn’t contain anything.

ResetTransformMatrix(self)

Revert the transformation matrix to identity matrix.

New in version 2.9.2.

SetAxisOrientation(self, xLeftRight, yBottomUp)

Sets the x and y axis orientation (i.e. the direction from lowest to highest values on the axis).

The default orientation is x axis from left to right and y axis from top down.

Parameters
• xLeftRight (bool) – True to set the x axis orientation to the natural left to right orientation, False to invert it.

• yBottomUp (bool) – True to set the y axis orientation to the natural bottom up orientation, False to invert it.

SetBackground(self, brush)

Sets the current background brush for the DC.

Parameters

brush (wx.Brush) –

SetBackgroundMode(self, mode)

mode may be one of SOLID and TRANSPARENT .

This setting determines whether text will be drawn with a background colour or not.

Parameters

mode (int) –

SetBrush(self, brush)

Sets the current brush for the DC.

If the argument is wx.NullBrush (or another invalid brush; see wx.Brush.IsOk ), the current brush is selected out of the device context (leaving wx.DC without any valid brush), allowing the current brush to be destroyed safely.

Parameters

brush (wx.Brush) –

wx.Brush, wx.MemoryDC (for the interpretation of colours when drawing into a monochrome bitmap)

SetClippingRegion(self, *args, **kw)

SetClippingRegion (self, x, y, width, 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.

The clipping region is an area to which drawing is restricted. Possible uses for the clipping region are for clipping text or for speeding up window redraws when only a known area of the screen is damaged.

Notice that you need to call DestroyClippingRegion if you want to set the clipping region exactly to the region specified.

Also note that if the clipping region is empty, any previously set clipping region is destroyed, i.e. it is equivalent to calling DestroyClippingRegion , and not to clipping out all drawing on the DC as might be expected.

Parameters
• x (int) –

• y (int) –

• width (int) –

• height (int) –

SetClippingRegion (self, pt, sz)

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

Parameters

SetClippingRegion (self, rect)

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

Parameters

rect (wx.Rect) –

SetDeviceClippingRegion(self, region)

Sets the clipping region for this device context.

Unlike SetClippingRegion , this function works with physical coordinates and not with the logical ones.

Parameters

region (wx.Region) –

SetDeviceOrigin(self, x, y)

Sets the device origin (i.e. the origin in pixels after scaling has been applied).

This function may be useful in Windows printing operations for placing a graphic on a page.

Parameters
• x (int) –

• y (int) –

SetFont(self, font)

Sets the current font for the DC.

If the argument is wx.NullFont (or another invalid font; see wx.Font.IsOk ), the current font is selected out of the device context (leaving wx.DC without any valid font), allowing the current font to be destroyed safely.

Parameters

font (wx.Font) –

wx.Font

SetLayoutDirection(self, dir)

Sets the current layout direction for the device context.

Parameters

dir (LayoutDirection) – May be either Layout_Default , Layout_LeftToRight or Layout_RightToLeft .

SetLogicalFunction(self, function)

Sets the current logical function for the device context.

It determines how a source pixel (from a pen or brush colour, or source device context if using Blit ) combines with a destination pixel in the current device context. Text drawing is not affected by this function.

The default is COPY , which simply draws with the current colour. The others combine the current colour and the background using a logical operation. INVERT is commonly used for drawing rubber bands or moving outlines, since drawing twice reverts to the original colour.

Parameters

function (RasterOperationMode) –

SetLogicalOrigin(self, x, y)

Change the offset used for translating wx.DC coordinates.

Parameters
• x (int) –

• y (int) –

SetLogicalScale(self, x, y)

Set the scale to use for translating wx.DC coordinates to the physical pixels.

The effect of calling this function is similar to that of calling SetUserScale .

Parameters
• x (float) –

• y (float) –

SetMapMode(self, mode)

The mapping mode of the device context defines the unit of measurement used to convert logical units to device units.

Note that in X, text drawing isn’t handled consistently with the mapping mode; a font is always specified in point size. However, setting the user scale (see SetUserScale ) scales the text appropriately. In Windows, scalable TrueType fonts are always used; in X, results depend on availability of fonts, but usually a reasonable match is found.

The coordinate origin is always at the top left of the screen/printer.

Drawing to a Windows printer device context uses the current mapping mode, but mapping mode is currently ignored for PostScript output.

Parameters

mode (MappingMode) –

SetPalette(self, palette)

If this is a window DC or memory DC, assigns the given palette to the window or bitmap associated with the DC.

If the argument is wx.NullPalette , the current palette is selected out of the device context, and the original palette restored.

Parameters

palette (wx.Palette) –

wx.Palette

SetPen(self, pen)

Sets the current pen for the DC.

If the argument is wx.NullPen (or another invalid pen; see wx.Pen.IsOk ), the current pen is selected out of the device context (leaving wx.DC without any valid pen), allowing the current pen to be destroyed safely.

Parameters

pen (wx.Pen) –

wx.MemoryDC for the interpretation of colours when drawing into a monochrome bitmap.

SetTextBackground(self, colour)

Sets the current text background colour for the DC.

Parameters

colour (wx.Colour) –

SetTextForeground(self, colour)

Sets the current text foreground colour for the DC.

Parameters

colour (wx.Colour) –

wx.MemoryDC for the interpretation of colours when drawing into a monochrome bitmap.

SetTransformMatrix(self, matrix)

Set the transformation matrix.

If transformation matrix is supported on the current system, the specified matrix will be used to transform between wx.DC and physical coordinates. Otherwise the function returns False and doesn’t change the coordinate mapping.

Parameters

matrix (wx.AffineMatrix2D) –

Return type

bool

New in version 2.9.2.

SetUserScale(self, xScale, yScale)

Sets the user scaling factor, useful for applications which require ‘zooming’.

Parameters
• xScale (float) –

• yScale (float) –

StartDoc(self, message)

Starts a document (only relevant when outputting to a printer).

message is a message to show while printing.

Parameters

message (string) –

Return type

bool

StartPage(self)

Starts a document page (only relevant when outputting to a printer).

StretchBlit(self, xdest, ydest, dstWidth, dstHeight, source, xsrc, ysrc, srcWidth, srcHeight, logicalFunc=COPY, useMask=False, xsrcMask=DefaultCoord, ysrcMask=DefaultCoord)

Copy from a source DC to this DC possibly changing the scale.

Unlike Blit , this method allows specifying different source and destination region sizes, meaning that it can stretch or shrink it while copying. The same can be achieved by changing the scale of the source or target DC but calling this method is simpler and can also be more efficient if the platform provides a native implementation of it.

The meaning of its other parameters is the same as with Blit , in particular all source coordinates are interpreted using the source DC coordinate system, i.e. are affected by its scale, origin translation and axis direction.

Parameters
• xdest (int) – Destination device context x position.

• ydest (int) – Destination device context y position.

• dstWidth (int) – Width of destination area.

• dstHeight (int) – Height of destination area.

• source (wx.DC) – Source device context.

• xsrc (int) – Source device context x position.

• ysrc (int) – Source device context y position.

• srcWidth (int) – Width of source area to be copied.

• srcHeight (int) – Height of source area to be copied.

• logicalFunc (RasterOperationMode) – Logical function to use, see SetLogicalFunction .

• useMask (bool) – If True, Blit does a transparent blit using the mask that is associated with the bitmap selected into the source device context. The Windows implementation does the following if MaskBlt cannot be used:

• Creates a temporary bitmap and copies the destination area into it.

• Copies the source area into the temporary bitmap using the specified logical function.

• Sets the masked area in the temporary bitmap to wx.BLACK by ANDing the mask bitmap with the temp bitmap with the foreground colour set to wx.WHITE and the bg colour set to wx.BLACK.

• Sets the unmasked area in the destination area to wx.BLACK by ANDing the mask bitmap with the destination area with the foreground colour set to wx.BLACK and the background colour set to wx.WHITE.

• ORs the temporary bitmap with the destination area.

• Deletes the temporary bitmap.

This sequence of operations ensures that the source’s transparent area need not be black, and logical functions are supported.

Note: on Windows, blitting with masks can be speeded up considerably by compiling wxWidgets with the USE_DC_CACHEING option enabled. You can also influence whether MaskBlt or the explicit mask blitting code above is used, by using wx.SystemOptions and setting the no-maskblt option to 1.

• xsrcMask (int) – Source x position on the mask. If both xsrcMask and ysrcMask are DefaultCoord, xsrc and ysrc will be assumed for the mask source position. Currently only implemented on Windows.

• ysrcMask (int) – Source y position on the mask. If both xsrcMask and ysrcMask are DefaultCoord, xsrc and ysrc will be assumed for the mask source position. Currently only implemented on Windows.

Return type

bool

Blit in wx.PostScriptDC, under X.

See wx.MemoryDC for typical usage.

New in version 2.9.0.

_DrawEllipseList(self, pyCoords, pyPens, pyBrushes)
Return type

PyObject

_DrawLineList(self, pyCoords, pyPens, pyBrushes)
Return type

PyObject

_DrawPointList(self, pyCoords, pyPens, pyBrushes)
Return type

PyObject

_DrawPolygonList(self, pyCoords, pyPens, pyBrushes)
Return type

PyObject

_DrawRectangleList(self, pyCoords, pyPens, pyBrushes)
Return type

PyObject

_DrawTextList(self, textList, pyPoints, foregroundList, backgroundList)
Return type

PyObject

__bool__(self)
Return type

int

__enter__(self)

__exit__(self, exc_type, exc_val, exc_tb)

__nonzero__(self)
Return type

int

### Properties¶

AsBitmap

Background

BackgroundMode

BoundingBox

Brush

CGContext

CharHeight

CharWidth

ClippingRect

Depth

DeviceOrigin

Font

FontMetrics

GdkDrawable

HDC

Handle

LayoutDirection

LogicalFunction

MapMode

MultiLineTextExtent

PPI

Pen

Pixel

Size

SizeMM

TextBackground

TextExtent

TextForeground

TransformMatrix