wx.GraphicsContext¶A wx.GraphicsContext instance is the object that is drawn upon.
It is created by a renderer using wx.GraphicsRenderer.CreateContext . This can be either directly using a renderer instance, or indirectly using the static convenience Create functions of wx.GraphicsContext that always delegate the task to the default renderer.
def OnPaint(self, event):
# Create paint DC
dc = wx.PaintDC(self)
# Create graphics context from it
gc = wx.GraphicsContext.Create(dc)
if gc:
# make a path that contains a circle and some lines
gc.SetPen(wx.RED_PEN)
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)
Note
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 wx.GraphicsContext.Flush or by destroying the context.
See also
Methods Summary¶All rendering will be done into a fully transparent temporary context. |
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Sets the clipping region to the intersection of the given region and the previously set clipping region. |
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Concatenates the passed in transform with the current transform of this context. |
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Creates a wx.GraphicsContext from a wx.Window. |
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Creates wx.GraphicsBitmap from an existing wx.Bitmap. |
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Creates wx.GraphicsBitmap from an existing wx.Image. |
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Creates a native brush from a wx.Brush. |
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Creates a native graphics font from a wx.Font and a text colour. |
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Creates a wx.GraphicsContext from a native context. |
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Creates a wx.GraphicsContext from a native window. |
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Creates a wx.GraphicsContext from a DC of unknown specific type. |
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Creates a native brush with a linear gradient. |
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Creates a native affine transformation matrix from the passed in values. |
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Creates a native graphics path which is initially empty. |
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Creates a native pen from a wx.Pen. |
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Creates a native brush with a radial gradient. |
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Extracts a sub-bitmap from an existing bitmap. |
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Helper to determine if a 0.5 offset should be applied for the drawing operation. |
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Draws the bitmap. |
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Draws an ellipse. |
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Draws the icon. |
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Draws a polygon. |
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Draws the path by first filling and then stroking. |
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Draws a rectangle. |
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Draws a rounded rectangle. |
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Draws text at the defined position. |
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Indicates whether the context should try to offset for pixel boundaries. |
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Done with that document (relevant only for printing / pdf etc.) |
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Composites back the drawings into the context with the opacity given at the |
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Ends the current page (relevant only for printing / pdf etc.) |
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Fills the path with the current brush. |
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Make sure that the current content of this context is immediately visible. |
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Convert DPI-independent pixel values to the value in pixels appropriate for the graphics context. |
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Returns the current shape antialiasing mode. |
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Returns bounding box of the current clipping region. |
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Returns the current compositing operator. |
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Returns the resolution of the graphics context in device points per inch. |
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Returns the current interpolation quality. |
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Returns the native context (CGContextRef for Core Graphics, Graphics pointer for GDIPlus and cairo_t pointer for cairo). |
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Fills the widths array with the widths from the beginning of text to the corresponding character of text. |
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Returns the size of the graphics context in device coordinates. |
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Gets the dimensions of the string using the currently selected font. |
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Gets the current transformation matrix of this context. |
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Returns the associated window if any. |
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Helper to determine if a 0.5 offset should be applied for the drawing operation. |
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Sets current state of the context to the state saved by a preceding call to |
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Push the current state (like transformations, clipping region and quality settings) of the context on a stack. |
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Resets the clipping to original shape. |
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Rotates the current transformation matrix (in radians). |
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Scales the current transformation matrix. |
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Sets the antialiasing mode, returns |
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Sets the brush for filling paths. |
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Sets the compositing operator, returns |
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Sets the font for drawing text. |
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Sets the interpolation quality, returns |
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Sets the pen used for stroking. |
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Sets the current transformation matrix of this context. |
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Helper to determine if a 0.5 offset should be applied for the drawing operation. |
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Begin a new document (relevant only for printing / pdf etc.) If there is a progress dialog, message will be shown. |
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Opens a new page (relevant only for printing / pdf etc.) with the given size in points. |
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Strokes a single line. |
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Stroke disconnected lines from begin to end points. |
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Stroke lines connecting all the points. |
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Strokes along a path with the current pen. |
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Convert pixel values of the current graphics context to DPI-independent pixel values. |
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Translates the current transformation matrix. |
Properties Summary¶See |
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Class API¶
Inheritance diagram for class GraphicsContext:
wx.GraphicsContext(GraphicsObject)¶A GraphicsContext instance is the object that is drawn upon.
BeginLayer(self, opacity)¶All rendering will be done into a fully transparent temporary context.
Layers can be nested by making balanced calls to BeginLayer /EndLayer().
opacity (wx.Double) –
Clip(self, *args, **kw)¶
Overloaded Implementations:
Clip (self, region)
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.
region (wx.Region) –
Note
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).
Clip (self, x, y, w, h)
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
x (wx.Double) –
y (wx.Double) –
w (wx.Double) –
h (wx.Double) –
ConcatTransform(self, matrix)¶Concatenates the passed in transform with the current transform of this context.
matrix (wx.GraphicsMatrix) –
Create(*args, **kw)¶ Overloaded Implementations:
Create (window)
Creates a wx.GraphicsContext from a wx.Window.
window (wx.Window) –
See also
Create (windowDC)
Creates a wx.GraphicsContext from a wx.WindowDC.
windowDC (wx.WindowDC) –
See also
Create (memoryDC)
Creates a wx.GraphicsContext from a wx.MemoryDC.
memoryDC (wx.MemoryDC) –
See also
Create (printerDC)
Creates a wx.GraphicsContext from a wx.PrinterDC.
Under GTK+, this will only work when using the GtkPrint printing backend which is available since GTK+ 2.10.
printerDC (wx.PrinterDC) –
See also
Create (metaFileDC)
Creates a wx.GraphicsContext from a EnhMetaFileDC.
This function, as EnhMetaFileDC class itself, is only available only under MSW.
metaFileDC (MetafileDC) –
See also
Create (image)
Creates a wx.GraphicsContext associated with a wx.Image.
The image specifies the size of the context as well as whether alpha is supported (if wx.Image.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.
image (wx.Image) –
New in version 2.9.3.
Create ()
Create a lightweight context that can be used only for measuring text.
Create (autoPaintDC)
CreateBitmap(self, bitmap)¶Creates wx.GraphicsBitmap from an existing wx.Bitmap.
Returns an invalid NullGraphicsBitmap on failure.
bitmap (wx.Bitmap) –
CreateBitmapFromImage(self, image)¶Creates wx.GraphicsBitmap from an existing wx.Image.
This method is more efficient than converting wx.Image to wx.Bitmap first and then calling CreateBitmap but otherwise has the same effect.
Returns an invalid NullGraphicsBitmap on failure.
image (wx.Image) –
New in version 2.9.3.
CreateBrush(self, brush)¶Creates a native brush from a wx.Brush.
brush (wx.Brush) –
CreateFont(self, *args, **kw)¶ Overloaded Implementations:
CreateFont (self, font, col=BLACK)
Creates a native graphics font from a wx.Font and a text colour.
Note
For Direct2D graphics fonts can be created from TrueType fonts only.
CreateFont (self, sizeInPixels, facename, flags=FONTFLAG_DEFAULT, col=BLACK)
Creates a font object with the specified attributes.
The use of overload taking wx.Font is preferred, see wx.GraphicsRenderer.CreateFont for more details.
sizeInPixels (float) –
facename (string) –
flags (int) –
col (wx.Colour) –
New in version 2.9.3.
Note
For Direct2D graphics fonts can be created from TrueType fonts only.
CreateFromNative(context)¶Creates a wx.GraphicsContext 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.
context –
CreateFromNativeWindow(window)¶Creates a wx.GraphicsContext from a native window.
window –
CreateFromUnknownDC(dc)¶Creates a wx.GraphicsContext from a DC of unknown specific type.
Creates a wx.GraphicsContext if dc is a supported type (i.e. has a corresponding Create method, e.g. wx.WindowDC or wx.MemoryDC). Returns None if the DC is unsupported.
This method is only useful as a helper in generic code that operates with wx.DC and doesn’t known its exact type. Use Create instead if you know that the DC is e.g. wx.WindowDC.
dc (wx.DC) –
New in version 4.1/wxWidgets-3.1.1.
CreateLinearGradientBrush(self, *args, **kw)¶ Overloaded Implementations:
CreateLinearGradientBrush (self, x1, y1, x2, y2, c1, c2, matrix=NullGraphicsMatrix)
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 wx.GraphicsGradientStops is new in wxWidgets 2.9.1.
The matrix parameter was added in wxWidgets 3.1.3
x1 (wx.Double) –
y1 (wx.Double) –
x2 (wx.Double) –
y2 (wx.Double) –
c1 (wx.Colour) –
c2 (wx.Colour) –
matrix (wx.GraphicsMatrix) –
CreateLinearGradientBrush (self, x1, y1, x2, y2, stops, matrix=NullGraphicsMatrix)
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
x1 (wx.Double) –
y1 (wx.Double) –
x2 (wx.Double) –
y2 (wx.Double) –
stops (wx.GraphicsGradientStops) –
matrix (wx.GraphicsMatrix) –
CreateMatrix(self, *args, **kw)¶ Overloaded Implementations:
CreateMatrix (self, a=1.0, b=0.0, c=0.0, d=1.0, tx=0.0, ty=0.0)
Creates a native affine transformation matrix from the passed in values.
The default parameters result in an identity matrix.
a (wx.Double) –
b (wx.Double) –
c (wx.Double) –
d (wx.Double) –
tx (wx.Double) –
ty (wx.Double) –
CreateMatrix (self, mat)
Creates a native affine transformation matrix from the passed generic one.
mat (wx.AffineMatrix2DBase) –
New in version 2.9.4.
CreatePath(self)¶Creates a native graphics path which is initially empty.
CreatePen(self, *args, **kw)¶ Overloaded Implementations:
CreatePen (self, pen)
Creates a native pen from a wx.Pen.
Prefer to use the overload taking wx.GraphicsPenInfo unless you already have a wx.Pen as constructing one only to pass it to this method is wasteful.
pen (wx.Pen) –
CreatePen (self, info)
Creates a native pen from a wx.GraphicsPenInfo.
info (wx.GraphicsPenInfo) –
New in version 4.1/wxWidgets-3.1.1.
CreateRadialGradientBrush(self, *args, **kw)¶ Overloaded Implementations:
CreateRadialGradientBrush (self, startX, startY, endX, endY, radius, oColor, cColor, matrix=NullGraphicsMatrix)
Creates a native brush with a radial gradient.
The brush originates at (startX, startY) and ends on a circle around (endX, endY) 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 wx.GraphicsGradientStops is new in wxWidgets 2.9.1.
The ability to apply a transformation matrix to the gradient was added in 3.1.3
startX (wx.Double) –
startY (wx.Double) –
endX (wx.Double) –
endY (wx.Double) –
radius (wx.Double) –
oColor (wx.Colour) –
cColor (wx.Colour) –
matrix (wx.GraphicsMatrix) –
CreateRadialGradientBrush (self, startX, startY, endX, endY, radius, stops, matrix=NullGraphicsMatrix)
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
startX (wx.Double) –
startY (wx.Double) –
endX (wx.Double) –
endY (wx.Double) –
radius (wx.Double) –
stops (wx.GraphicsGradientStops) –
matrix (wx.GraphicsMatrix) –
CreateSubBitmap(self, bitmap, x, y, w, h)¶Extracts a sub-bitmap from an existing bitmap.
bitmap (wx.GraphicsBitmap) –
x (wx.Double) –
y (wx.Double) –
w (wx.Double) –
h (wx.Double) –
DisableOffset(self)¶Helper to determine if a 0.5 offset should be applied for the drawing operation.
DrawBitmap(self, *args, **kw)¶ Overloaded Implementations:
DrawBitmap (self, bmp, x, y, w, h)
Draws the bitmap.
In case of a mono bitmap, this is treated as a mask and the current brushed is used for filling.
bmp (wx.GraphicsBitmap) –
x (wx.Double) –
y (wx.Double) –
w (wx.Double) –
h (wx.Double) –
DrawBitmap (self, bmp, x, y, w, h)
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
bmp (wx.Bitmap) –
x (wx.Double) –
y (wx.Double) –
w (wx.Double) –
h (wx.Double) –
DrawEllipse(self, x, y, w, h)¶Draws an ellipse.
x (wx.Double) –
y (wx.Double) –
w (wx.Double) –
h (wx.Double) –
DrawIcon(self, icon, x, y, w, h)¶Draws the icon.
icon (wx.Icon) –
x (wx.Double) –
y (wx.Double) –
w (wx.Double) –
h (wx.Double) –
DrawLines(self, point2Ds, fillStyle=ODDEVEN_RULE)¶Draws a polygon.
DrawPath(self, path, fillStyle=ODDEVEN_RULE)¶Draws the path by first filling and then stroking.
path (wx.GraphicsPath) –
fillStyle (PolygonFillMode) –
DrawRectangle(self, x, y, w, h)¶Draws a rectangle.
x (wx.Double) –
y (wx.Double) –
w (wx.Double) –
h (wx.Double) –
DrawRoundedRectangle(self, x, y, w, h, radius)¶Draws a rounded rectangle.
x (wx.Double) –
y (wx.Double) –
w (wx.Double) –
h (wx.Double) –
radius (wx.Double) –
DrawText(self, *args, **kw)¶ Overloaded Implementations:
DrawText (self, str, x, y)
Draws text at the defined position.
str (string) –
x (wx.Double) –
y (wx.Double) –
DrawText (self, str, x, y, angle)
Draws text at the defined position.
str (string) – The text to draw.
x (wx.Double) – The x coordinate position to draw the text at.
y (wx.Double) – The y coordinate position to draw the text at.
angle (wx.Double) – The angle, in radians, relative to the (default) horizontal direction to draw the string.
DrawText (self, str, x, y, backgroundBrush)
Draws text at the defined position.
str (string) – The text to draw.
x (wx.Double) – The x coordinate position to draw the text at.
y (wx.Double) – The y coordinate position to draw the text at.
backgroundBrush (wx.GraphicsBrush) – Brush to fill the text with.
DrawText (self, str, x, y, angle, backgroundBrush)
Draws text at the defined position.
str (string) – The text to draw.
x (wx.Double) – The x coordinate position to draw the text at.
y (wx.Double) – The y coordinate position to draw the text at.
angle (wx.Double) – The angle, in radians, relative to the (default) horizontal direction to draw the string.
backgroundBrush (wx.GraphicsBrush) – Brush to fill the text with.
EnableOffset(self, enable=True)¶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.
enable (bool) –
EndDoc(self)¶Done with that document (relevant only for printing / pdf etc.)
EndLayer(self)¶Composites back the drawings into the context with the opacity given at the BeginLayer call.
EndPage(self)¶Ends the current page (relevant only for printing / pdf etc.)
FillPath(self, path, fillStyle=ODDEVEN_RULE)¶Fills the path with the current brush.
path (wx.GraphicsPath) –
fillStyle (PolygonFillMode) –
Flush(self)¶Make sure that the current content of this context is immediately visible.
FromDIP(self, *args, **kw)¶ Overloaded Implementations:
FromDIP (self, sz)
Convert DPI-independent pixel values to the value in pixels appropriate for the graphics context.
See Window.FromDIP(const Size& sz) and DC.FromDIP(const Size& sz) for more info about converting device independent pixel values.
New in version 4.1/wxWidgets-3.1.7.
FromDIP (self, pt)
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
FromDIP (self, d)
Convert DPI-independent value in pixels to the value in pixels appropriate for the graphics context.
This is the same as FromDIP(const Size& sz) overload, but assumes that the resolution is the same in horizontal and vertical directions.
d (int) –
int
New in version 4.1/wxWidgets-3.1.7.
GetAntialiasMode(self)¶Returns the current shape antialiasing mode.
GetClipBox(self, x, y, w, h)¶Returns bounding box of the current clipping region.
x (wx.Double) –
y (wx.Double) –
w (wx.Double) –
h (wx.Double) –
New in version 4.1/wxWidgets-3.1.1.
Note
If clipping region is empty, then empty rectangle is returned (x, y, w, h are set to zero).
GetCompositionMode(self)¶Returns the current compositing operator.
GetDPI(self)¶Returns the resolution of the graphics context in device points per inch.
tuple
( dpiX, dpiY )
GetInterpolationQuality(self)¶Returns the current interpolation quality.
GetNativeContext(self)¶Returns the native context (CGContextRef for Core Graphics, Graphics pointer for GDIPlus and cairo_t pointer for cairo).
GetPartialTextExtents(self, text)¶Fills the widths array with the widths from the beginning of text to the corresponding character of text.
text (string) –
list of floats
GetSize(self)¶Returns the size of the graphics context in device coordinates.
tuple
( width, height )
GetFullTextExtent(self, *args, **kw)¶ Overloaded Implementations:
GetFullTextExtent (self, text)
Gets the dimensions of the string using the currently selected font.
text (string) – The text string to measure.
tuple
( width, height, descent, externalLeading )
GetFullTextExtent (self, text)
Gets the dimensions of the string using the currently selected font.
tuple
( width, height )
GetTransform(self)¶Gets the current transformation matrix of this context.
GetWindow(self)¶Returns the associated window if any.
If this context was created using Create overload taking wx.Window or wx.WindowDC, this method returns the corresponding window. Otherwise returns None.
A possibly None window pointer.
New in version 4.1/wxWidgets-3.1.2.
OffsetEnabled(self)¶Helper to determine if a 0.5 offset should be applied for the drawing operation.
bool
PopState(self)¶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(self)¶Push the current state (like transformations, clipping region and quality settings) of the context on a stack.
Multiple balanced calls to PushState and PopState can be nested.
See also
ResetClip(self)¶Resets the clipping to original shape.
Rotate(self, angle)¶Rotates the current transformation matrix (in radians).
angle (wx.Double) –
Scale(self, xScale, yScale)¶Scales the current transformation matrix.
xScale (wx.Double) –
yScale (wx.Double) –
SetAntialiasMode(self, antialias)¶Sets the antialiasing mode, returns True if it supported.
antialias (AntialiasMode) –
bool
SetBrush(self, *args, **kw)¶Sets the brush for filling paths.
Overloaded Implementations:
SetBrush (self, brush)
brush (wx.Brush) –
SetBrush (self, brush)
brush (wx.GraphicsBrush) –
SetCompositionMode(self, op)¶Sets the compositing operator, returns True if it supported.
op (CompositionMode) –
bool
SetFont(self, *args, **kw)¶ Overloaded Implementations:
SetFont (self, font, colour)
Sets the font for drawing text.
Note
For Direct2D only TrueType fonts can be used.
SetFont (self, font)
Sets the font for drawing text.
font (wx.GraphicsFont) –
SetInterpolationQuality(self, interpolation)¶Sets the interpolation quality, returns True if it is supported.
interpolation (InterpolationQuality) –
bool
Note
Not implemented in Cairo backend currently.
SetPen(self, *args, **kw)¶Sets the pen used for stroking.
Overloaded Implementations:
SetPen (self, pen)
pen (wx.Pen) –
SetPen (self, pen)
pen (wx.GraphicsPen) –
SetTransform(self, matrix)¶Sets the current transformation matrix of this context.
matrix (wx.GraphicsMatrix) –
ShouldOffset(self)¶Helper to determine if a 0.5 offset should be applied for the drawing operation.
bool
StartDoc(self, message)¶Begin a new document (relevant only for printing / pdf etc.) If there is a progress dialog, message will be shown.
message (string) –
bool
StartPage(self, width=0, height=0)¶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.)
width (wx.Double) –
height (wx.Double) –
StrokeLine(self, x1, y1, x2, y2)¶Strokes a single line.
x1 (wx.Double) –
y1 (wx.Double) –
x2 (wx.Double) –
y2 (wx.Double) –
StrokeLineSegments(self, beginPoint2Ds, endPoint2Ds)¶Stroke disconnected lines from begin to end points.
StrokeLines(self, point2Ds)¶Stroke lines connecting all the points.
StrokePath(self, path)¶Strokes along a path with the current pen.
path (wx.GraphicsPath) –
ToDIP(self, *args, **kw)¶ Overloaded Implementations:
ToDIP (self, sz)
Convert pixel values of the current graphics context to DPI-independent pixel values.
See Window.ToDIP(const Size& sz) and DC.ToDIP(const Size& sz) for more info about converting device independent pixel values.
New in version 4.1/wxWidgets-3.1.7.
ToDIP (self, pt)
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts.
ToDIP (self, d)
Convert pixel values of the current graphics context to DPI-independent pixel values.
This is the same as ToDIP(const Size& sz) overload, but assumes that the resolution is the same in horizontal and vertical directions.
d (int) –
int
New in version 4.1/wxWidgets-3.1.7.
Translate(self, dx, dy)¶Translates the current transformation matrix.
dx (wx.Double) –
dy (wx.Double) –
AntialiasMode¶See GetAntialiasMode and SetAntialiasMode
CompositionMode¶See GetCompositionMode and SetCompositionMode
InterpolationQuality¶NativeContext¶See GetNativeContext
TextExtent¶See GetTextExtent
Transform¶See GetTransform and SetTransform