wxDC - Functions for wxDC class
Please see following description for synopsis
wxDC(3) Erlang Module Definition wxDC(3)
NAME
wxDC - Functions for wxDC class
DESCRIPTION
A wxDC is a "device context" onto which graphics and text can be drawn.
It is intended to represent different output devices and offers a com-
mon abstract API for drawing on any of them.
wxWidgets offers an alternative drawing API based on the modern drawing
backends GDI+, CoreGraphics, Cairo and Direct2D. See wxGraphicsContext,
wxGraphicsRenderer and related classes. There is also a wxGCDC linking
the APIs by offering the wxDC API on top of a wxGraphicsContext.
wxDC is an abstract base class and cannot be created directly. Use
wxPaintDC, wxClientDC, wxWindowDC, wxScreenDC, wxMemoryDC or wxPrint-
erDC (not implemented in wx). Notice that device contexts which are
associated with windows (i.e. wxClientDC, wxWindowDC and wxPaintDC) 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 {X,Y} parameter instead of the two
wxCoord ones or {X,Y} and {Width,Height} instead of the four wxCoord
parameters.
Beginning with wxWidgets 2.9.0 the entire wxDC code has been reorga-
nized. All platform dependent code (actually all drawing code) has been
moved into backend classes which derive from a common wxDCImpl class.
The user-visible classes such as wxClientDC and wxPaintDC merely for-
ward all calls to the backend implementation.
Device and logical units
In the wxDC 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 wxDC functions use instead logical units, unless where explicitly
stated. Logical units are arbitrary units mapped to device units using
the current mapping mode (see setMapMode/2).
This mechanism allows reusing the same code which prints on e.g. a win-
dow on the screen to print on e.g. a paper.
Support for Transparency / Alpha Channel
In general wxDC methods don't support alpha transparency and the alpha
component of wx_color() is simply ignored and you need to use wxGraph-
icsContext for full transparency support. There are, however, a few
exceptions: first, under macOS and GTK+ 3 colours with alpha channel
are supported in all the normal wxDC-derived classes as they use
wxGraphicsContext internally. Second, under all platforms wxSVGFileDC
(not implemented in wx) also fully supports alpha channel. In both of
these cases the instances of wxPen or wxBrush that are built from
wx_color() use the colour's alpha values when stroking or filling.
Support for Transformation Matrix
On some platforms (currently under MSW, GTK+ 3, macOS) wxDC has support
for applying an arbitrary affine transformation matrix to its coordi-
nate system (since 3.1.1 this feature is also supported by wxGCDC in
all ports). Call CanUseTransformMatrix() (not implemented in wx) to
check if this support is available and then call SetTransformMatrix()
(not implemented in wx) if it is. If the transformation matrix is not
supported, SetTransformMatrix() (not implemented in wx) always simply
returns false and doesn't do anything.
This feature is only available when wxUSE_DC_TRANSFORM_MATRIX build
option is enabled.
See: Overview dc, wxGraphicsContext, wxDCFontChanger (not implemented
in wx), wxDCTextColourChanger (not implemented in wx), wxDCPenChanger
(not implemented in wx), wxDCBrushChanger (not implemented in wx), wxD-
CClipper (not implemented in wx)
wxWidgets docs: wxDC
DATA TYPES
wxDC() = wx:wx_object()
EXPORTS
blit(This, Dest, Size, Source, Src) -> boolean()
Types:
This = wxDC()
Dest = {X :: integer(), Y :: integer()}
Size = {W :: integer(), H :: integer()}
Source = wxDC()
Src = {X :: integer(), Y :: integer()}
blit(This, Dest, Size, Source, Src, Options :: [Option]) ->
boolean()
Types:
This = wxDC()
Dest = {X :: integer(), Y :: integer()}
Size = {W :: integer(), H :: integer()}
Source = wxDC()
Src = {X :: integer(), Y :: integer()}
Option =
{rop, wx:wx_enum()} |
{useMask, boolean()} |
{srcPtMask, {X :: integer(), Y :: integer()}}
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 copy-
ing, use StretchBlit() (not implemented in wx).
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.
Remark: There is partial support for blit/6 in wxPostScriptDC,
under X.
See: StretchBlit() (not implemented in wx), wxMemoryDC,
wxBitmap, wxMask
calcBoundingBox(This, X, Y) -> ok
Types:
This = wxDC()
X = Y = integer()
Adds the specified point to the bounding box which can be
retrieved with minX/1, maxX/1 and minY/1, maxY/1 functions.
See: resetBoundingBox/1
clear(This) -> ok
Types:
This = wxDC()
Clears the device context using the current background brush.
Note that setBackground/2 method must be used to set the brush
used by clear/1, the brush used for filling the shapes set by
setBrush/2 is ignored by it.
If no background brush was set, solid white brush is used to
clear the device context.
crossHair(This, Pt) -> ok
Types:
This = wxDC()
Pt = {X :: integer(), Y :: integer()}
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
destroyClippingRegion(This) -> ok
Types:
This = wxDC()
Destroys the current clipping region so that none of the DC is
clipped.
See: setClippingRegion/3
deviceToLogicalX(This, X) -> integer()
Types:
This = wxDC()
X = integer()
Convert device X coordinate to logical coordinate, using the
current mapping mode, user scale factor, device origin and axis
orientation.
deviceToLogicalXRel(This, X) -> integer()
Types:
This = wxDC()
X = integer()
Convert device X coordinate to relative logical coordinate,
using the current mapping mode and user scale factor but ignor-
ing the axis orientation.
Use this for converting a width, for example.
deviceToLogicalY(This, Y) -> integer()
Types:
This = wxDC()
Y = integer()
Converts device Y coordinate to logical coordinate, using the
current mapping mode, user scale factor, device origin and axis
orientation.
deviceToLogicalYRel(This, Y) -> integer()
Types:
This = wxDC()
Y = integer()
Convert device Y coordinate to relative logical coordinate,
using the current mapping mode and user scale factor but ignor-
ing the axis orientation.
Use this for converting a height, for example.
drawArc(This, PtStart, PtEnd, Centre) -> ok
Types:
This = wxDC()
PtStart = PtEnd = Centre = {X :: integer(), Y :: integer()}
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
drawBitmap(This, Bmp, Pt) -> ok
Types:
This = wxDC()
Bmp = wxBitmap:wxBitmap()
Pt = {X :: integer(), Y :: integer()}
drawBitmap(This, Bmp, Pt, Options :: [Option]) -> ok
Types:
This = wxDC()
Bmp = wxBitmap:wxBitmap()
Pt = {X :: integer(), Y :: integer()}
Option = {useMask, boolean()}
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
drawCheckMark(This, Rect) -> ok
Types:
This = wxDC()
Rect =
{X :: integer(),
Y :: integer(),
W :: integer(),
H :: integer()}
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
drawCircle(This, Pt, Radius) -> ok
Types:
This = wxDC()
Pt = {X :: integer(), Y :: integer()}
Radius = integer()
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
drawEllipse(This, Rect) -> ok
Types:
This = wxDC()
Rect =
{X :: integer(),
Y :: integer(),
W :: integer(),
H :: integer()}
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
drawEllipse(This, Pt, Size) -> ok
Types:
This = wxDC()
Pt = {X :: integer(), Y :: integer()}
Size = {W :: integer(), H :: integer()}
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
drawEllipticArc(This, Pt, Sz, Sa, Ea) -> ok
Types:
This = wxDC()
Pt = {X :: integer(), Y :: integer()}
Sz = {W :: integer(), H :: integer()}
Sa = Ea = number()
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
drawIcon(This, Icon, Pt) -> ok
Types:
This = wxDC()
Icon = wxIcon:wxIcon()
Pt = {X :: integer(), Y :: integer()}
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
drawLabel(This, Text, Rect) -> ok
Types:
This = wxDC()
Text = unicode:chardata()
Rect =
{X :: integer(),
Y :: integer(),
W :: integer(),
H :: integer()}
drawLabel(This, Text, Rect, Options :: [Option]) -> ok
Types:
This = wxDC()
Text = unicode:chardata()
Rect =
{X :: integer(),
Y :: integer(),
W :: integer(),
H :: integer()}
Option = {alignment, integer()} | {indexAccel, integer()}
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
drawLine(This, Pt1, Pt2) -> ok
Types:
This = wxDC()
Pt1 = Pt2 = {X :: integer(), Y :: integer()}
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
drawLines(This, Points) -> ok
Types:
This = wxDC()
Points = [{X :: integer(), Y :: integer()}]
drawLines(This, Points, Options :: [Option]) -> ok
Types:
This = wxDC()
Points = [{X :: integer(), Y :: integer()}]
Option = {xoffset, integer()} | {yoffset, integer()}
Draws lines using an array of points of size n adding the
optional offset coordinate.
The current pen is used for drawing the lines.
drawPolygon(This, Points) -> ok
Types:
This = wxDC()
Points = [{X :: integer(), Y :: integer()}]
drawPolygon(This, Points, Options :: [Option]) -> ok
Types:
This = wxDC()
Points = [{X :: integer(), Y :: integer()}]
Option =
{xoffset, integer()} |
{yoffset, integer()} |
{fillStyle, wx:wx_enum()}
Draws a filled polygon using an array of points of size n,
adding the optional offset coordinate.
The first and last points are automatically closed.
The last argument specifies the fill rule: wxODDEVEN_RULE (the
default) or wxWINDING_RULE.
The current pen is used for drawing the outline, and the current
brush for filling the shape. Using a transparent brush sup-
presses filling.
drawPoint(This, Pt) -> ok
Types:
This = wxDC()
Pt = {X :: integer(), Y :: integer()}
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
drawRectangle(This, Rect) -> ok
Types:
This = wxDC()
Rect =
{X :: integer(),
Y :: integer(),
W :: integer(),
H :: integer()}
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
drawRectangle(This, Pt, Sz) -> ok
Types:
This = wxDC()
Pt = {X :: integer(), Y :: integer()}
Sz = {W :: integer(), H :: integer()}
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
drawRotatedText(This, Text, Point, Angle) -> ok
Types:
This = wxDC()
Text = unicode:chardata()
Point = {X :: integer(), Y :: integer()}
Angle = number()
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
drawRoundedRectangle(This, Rect, Radius) -> ok
Types:
This = wxDC()
Rect =
{X :: integer(),
Y :: integer(),
W :: integer(),
H :: integer()}
Radius = number()
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
drawRoundedRectangle(This, Pt, Sz, Radius) -> ok
Types:
This = wxDC()
Pt = {X :: integer(), Y :: integer()}
Sz = {W :: integer(), H :: integer()}
Radius = number()
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
drawText(This, Text, Pt) -> ok
Types:
This = wxDC()
Text = unicode:chardata()
Pt = {X :: integer(), Y :: integer()}
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
endDoc(This) -> ok
Types:
This = wxDC()
Ends a document (only relevant when outputting to a printer).
endPage(This) -> ok
Types:
This = wxDC()
Ends a document page (only relevant when outputting to a
printer).
floodFill(This, Pt, Col) -> boolean()
Types:
This = wxDC()
Pt = {X :: integer(), Y :: integer()}
Col = wx:wx_colour()
floodFill(This, Pt, Col, Options :: [Option]) -> boolean()
Types:
This = wxDC()
Pt = {X :: integer(), Y :: integer()}
Col = wx:wx_colour()
Option = {style, wx:wx_enum()}
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
getBackground(This) -> wxBrush:wxBrush()
Types:
This = wxDC()
Gets the brush used for painting the background.
See: setBackground/2
getBackgroundMode(This) -> integer()
Types:
This = wxDC()
Returns the current background mode: wxPENSTYLE_SOLID or wxPEN-
STYLE_TRANSPARENT.
See: setBackgroundMode/2
getBrush(This) -> wxBrush:wxBrush()
Types:
This = wxDC()
Gets the current brush.
See: setBrush/2
getCharHeight(This) -> integer()
Types:
This = wxDC()
Gets the character height of the currently set font.
getCharWidth(This) -> integer()
Types:
This = wxDC()
Gets the average character width of the currently set font.
getClippingBox(This) -> Result
Types:
Result =
{X :: integer(),
Y :: integer(),
Width :: integer(),
Height :: integer()}
This = wxDC()
Gets the rectangle surrounding the current clipping region. If
no clipping region is set this function returns the extent of
the device context. @remarks Clipping region is given in logical
coordinates. @param x If non-<span class='literal'>NULL</span>,
filled in with the logical horizontal coordinate of the top left
corner of the clipping region if the function returns true or 0
otherwise. @param y If non-<span class='literal'>NULL</span>,
filled in with the logical vertical coordinate of the top left
corner of the clipping region if the function returns true or 0
otherwise. @param width If non-<span class='lit-
eral'>NULL</span>, filled in with the width of the clipping
region if the function returns true or the device context width
otherwise. @param height If non-<span class='lit-
eral'>NULL</span>, filled in with the height of the clipping
region if the function returns true or the device context height
otherwise.
Return: true if there is a clipping region or false if there is
no active clipping region (note that this return value is avail-
able only since wxWidgets 3.1.2, this function didn't return
anything in the previous versions).
getFont(This) -> wxFont:wxFont()
Types:
This = wxDC()
Gets the current font.
Notice that even although each device context object has some
default font after creation, this method would return a ?wxNull-
Font initially and only after calling setFont/2 a valid font is
returned.
getLayoutDirection(This) -> wx:wx_enum()
Types:
This = wxDC()
Gets the current layout direction of the device context.
On platforms where RTL layout is supported, the return value
will either be wxLayout_LeftToRight or wxLayout_RightToLeft. If
RTL layout is not supported, the return value will be wxLay-
out_Default.
See: setLayoutDirection/2
getLogicalFunction(This) -> wx:wx_enum()
Types:
This = wxDC()
Gets the current logical function.
See: setLogicalFunction/2
getMapMode(This) -> wx:wx_enum()
Types:
This = wxDC()
Gets the current mapping mode for the device context.
See: setMapMode/2
getMultiLineTextExtent(This, String) ->
{W :: integer(), H :: integer()}
Types:
This = wxDC()
String = unicode:chardata()
Gets the dimensions of the string using the currently selected
font.
string is the text string to measure.
Return: The text extent as a {Width,Height} object.
Note: This function works with both single-line and multi-line
strings.
See: wxFont, setFont/2, getPartialTextExtents/2, getTextExtent/3
getMultiLineTextExtent(This, String, Options :: [Option]) ->
{W :: integer(),
H :: integer(),
HeightLine :: integer()}
Types:
This = wxDC()
String = unicode:chardata()
Option = {font, wxFont:wxFont()}
Gets the dimensions of the string using the currently selected
font.
string is the text string to measure, heightLine, if non NULL,
is where to store the height of a single line.
The text extent is set in the given w and h pointers.
If the optional parameter font is specified and valid, then it
is used for the text extent calculation, otherwise the currently
selected font is used.
If string is empty, its horizontal extent is 0 but, for conve-
nience when using this function for allocating enough space for
a possibly multi-line string, its vertical extent is the same as
the height of an empty line of text. Please note that this be-
haviour differs from that of getTextExtent/3.
Note: This function works with both single-line and multi-line
strings.
See: wxFont, setFont/2, getPartialTextExtents/2, getTextExtent/3
getPartialTextExtents(This, Text) -> Result
Types:
Result = {Res :: boolean(), Widths :: [integer()]}
This = wxDC()
Text = unicode:chardata()
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/3, 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.
See: getMultiLineTextExtent/3, getTextExtent/3
getPen(This) -> wxPen:wxPen()
Types:
This = wxDC()
Gets the current pen.
See: setPen/2
getPixel(This, Pos) -> Result
Types:
Result = {Res :: boolean(), Colour :: wx:wx_colour4()}
This = wxDC()
Pos = {X :: integer(), Y :: integer()}
Gets in colour the colour at the specified location.
This method isn't available for wxPostScriptDC or wxMetafileDC
(not implemented in wx) nor for any DC in wxOSX port and simply
returns false there.
Note: Setting a pixel can be done using drawPoint/2.
Note: This method shouldn't be used with wxPaintDC as accessing
the DC while drawing can result in unexpected results, notably
in wxGTK.
getPPI(This) -> {W :: integer(), H :: integer()}
Types:
This = wxDC()
Returns the resolution of the device in pixels per inch.
getSize(This) -> {W :: integer(), H :: integer()}
Types:
This = wxDC()
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
getSizeMM(This) -> {W :: integer(), H :: integer()}
Types:
This = wxDC()
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
getTextBackground(This) -> wx:wx_colour4()
Types:
This = wxDC()
Gets the current text background colour.
See: setTextBackground/2
getTextExtent(This, String) -> {W :: integer(), H :: integer()}
Types:
This = wxDC()
String = unicode:chardata()
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
getTextExtent(This, String, Options :: [Option]) -> Result
Types:
Result =
{W :: integer(),
H :: integer(),
Descent :: integer(),
ExternalLeading :: integer()}
This = wxDC()
String = unicode:chardata()
Option = {theFont, wxFont:wxFont()}
Gets the dimensions of the string using the currently selected
font.
string is the text string to measure, 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).
The text extent is returned in w and h pointers or as a
{Width,Height} object depending on which version of this func-
tion is used.
If the optional parameter font is specified and valid, then it
is used for the text extent calculation. Otherwise the currently
selected font is.
If string is empty, its extent is 0 in both directions, as
expected.
Note: This function only works with single-line strings.
See: wxFont, setFont/2, getPartialTextExtents/2, getMultiLine-
TextExtent/3
getTextForeground(This) -> wx:wx_colour4()
Types:
This = wxDC()
Gets the current text foreground colour.
See: setTextForeground/2
getUserScale(This) -> {X :: number(), Y :: number()}
Types:
This = wxDC()
Gets the current user scale factor.
See: setUserScale/3
gradientFillConcentric(This, Rect, InitialColour, DestColour) ->
ok
Types:
This = wxDC()
Rect =
{X :: integer(),
Y :: integer(),
W :: integer(),
H :: integer()}
InitialColour = DestColour = wx:wx_colour()
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.
Note: Currently this function is very slow, don't use it for
real-time drawing.
gradientFillConcentric(This, Rect, InitialColour, DestColour,
CircleCenter) ->
ok
Types:
This = wxDC()
Rect =
{X :: integer(),
Y :: integer(),
W :: integer(),
H :: integer()}
InitialColour = DestColour = wx:wx_colour()
CircleCenter = {X :: integer(), Y :: integer()}
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 cir-
cle in the specified rect.
Note: Currently this function is very slow, don't use it for
real-time drawing.
gradientFillLinear(This, Rect, InitialColour, DestColour) -> ok
Types:
This = wxDC()
Rect =
{X :: integer(),
Y :: integer(),
W :: integer(),
H :: integer()}
InitialColour = DestColour = wx:wx_colour()
gradientFillLinear(This, Rect, InitialColour, DestColour,
Options :: [Option]) ->
ok
Types:
This = wxDC()
Rect =
{X :: integer(),
Y :: integer(),
W :: integer(),
H :: integer()}
InitialColour = DestColour = wx:wx_colour()
Option = {nDirection, wx:wx_enum()}
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 rectan-
gle and destColour on the right one.
logicalToDeviceX(This, X) -> integer()
Types:
This = wxDC()
X = integer()
Converts logical X coordinate to device coordinate, using the
current mapping mode, user scale factor, device origin and axis
orientation.
logicalToDeviceXRel(This, X) -> integer()
Types:
This = wxDC()
X = integer()
Converts logical X coordinate to relative device coordinate,
using the current mapping mode and user scale factor but ignor-
ing the axis orientation.
Use this for converting a width, for example.
logicalToDeviceY(This, Y) -> integer()
Types:
This = wxDC()
Y = integer()
Converts logical Y coordinate to device coordinate, using the
current mapping mode, user scale factor, device origin and axis
orientation.
logicalToDeviceYRel(This, Y) -> integer()
Types:
This = wxDC()
Y = integer()
Converts logical Y coordinate to relative device coordinate,
using the current mapping mode and user scale factor but ignor-
ing the axis orientation.
Use this for converting a height, for example.
maxX(This) -> integer()
Types:
This = wxDC()
Gets the maximum horizontal extent used in drawing commands so
far.
maxY(This) -> integer()
Types:
This = wxDC()
Gets the maximum vertical extent used in drawing commands so
far.
minX(This) -> integer()
Types:
This = wxDC()
Gets the minimum horizontal extent used in drawing commands so
far.
minY(This) -> integer()
Types:
This = wxDC()
Gets the minimum vertical extent used in drawing commands so
far.
isOk(This) -> boolean()
Types:
This = wxDC()
Returns true if the DC is ok to use.
resetBoundingBox(This) -> ok
Types:
This = wxDC()
Resets the bounding box: after a call to this function, the
bounding box doesn't contain anything.
See: calcBoundingBox/3
setAxisOrientation(This, XLeftRight, YBottomUp) -> ok
Types:
This = wxDC()
XLeftRight = YBottomUp = boolean()
Sets the x and y axis orientation (i.e. the direction from low-
est to highest values on the axis).
The default orientation is x axis from left to right and y axis
from top down.
setBackground(This, Brush) -> ok
Types:
This = wxDC()
Brush = wxBrush:wxBrush()
Sets the current background brush for the DC.
setBackgroundMode(This, Mode) -> ok
Types:
This = wxDC()
Mode = integer()
mode may be one of wxPENSTYLE_SOLID and wxPENSTYLE_TRANSPARENT.
This setting determines whether text will be drawn with a back-
ground colour or not.
setBrush(This, Brush) -> ok
Types:
This = wxDC()
Brush = wxBrush:wxBrush()
Sets the current brush for the DC.
If the argument is ?wxNullBrush (or another invalid brush; see
wxBrush:isOk/1), the current brush is selected out of the device
context (leaving wxDC without any valid brush), allowing the
current brush to be destroyed safely.
See: wxBrush, wxMemoryDC, (for the interpretation of colours
when drawing into a monochrome bitmap)
setClippingRegion(This, Rect) -> ok
Types:
This = wxDC()
Rect =
{X :: integer(),
Y :: integer(),
W :: integer(),
H :: integer()}
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
setClippingRegion(This, Pt, Sz) -> ok
Types:
This = wxDC()
Pt = {X :: integer(), Y :: integer()}
Sz = {W :: integer(), H :: integer()}
This is an overloaded member function, provided for convenience.
It differs from the above function only in what argument(s) it
accepts.
setDeviceOrigin(This, X, Y) -> ok
Types:
This = wxDC()
X = Y = integer()
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.
setFont(This, Font) -> ok
Types:
This = wxDC()
Font = wxFont:wxFont()
Sets the current font for the DC.
If the argument is ?wxNullFont (or another invalid font; see
wxFont:isOk/1), the current font is selected out of the device
context (leaving wxDC without any valid font), allowing the cur-
rent font to be destroyed safely.
See: wxFont
setLayoutDirection(This, Dir) -> ok
Types:
This = wxDC()
Dir = wx:wx_enum()
Sets the current layout direction for the device context.
See: getLayoutDirection/1
setLogicalFunction(This, Function) -> ok
Types:
This = wxDC()
Function = wx:wx_enum()
Sets the current logical function for the device context.
Note: This function is not fully supported in all ports, due to
the limitations of the underlying drawing model. Notably, wxIN-
VERT which was commonly used for drawing rubber bands or other
moving outlines in the past, is not, and will not, be supported
by wxGTK3 and wxMac. The suggested alternative is to draw tempo-
rarily objects normally and refresh the (affected part of the)
window to remove them later.
It determines how a source pixel (from a pen or brush colour, or
source device context if using blit/6) combines with a destina-
tion pixel in the current device context. Text drawing is not
affected by this function.
See ?wxRasterOperationMode enumeration values for more info.
The default is wxCOPY, which simply draws with the current
colour. The others combine the current colour and the background
using a logical operation.
setMapMode(This, Mode) -> ok
Types:
This = wxDC()
Mode = wx:wx_enum()
The mapping mode of the device context defines the unit of mea-
surement 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/3) 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 Post-
Script output.
setPalette(This, Palette) -> ok
Types:
This = wxDC()
Palette = wxPalette:wxPalette()
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 ?wxNullPalette, the current palette is
selected out of the device context, and the original palette
restored.
See: wxPalette
setPen(This, Pen) -> ok
Types:
This = wxDC()
Pen = wxPen:wxPen()
Sets the current pen for the DC.
If the argument is ?wxNullPen (or another invalid pen; see
wxPen:isOk/1), the current pen is selected out of the device
context (leaving wxDC without any valid pen), allowing the cur-
rent pen to be destroyed safely.
See: wxMemoryDC, for the interpretation of colours when drawing
into a monochrome bitmap
setTextBackground(This, Colour) -> ok
Types:
This = wxDC()
Colour = wx:wx_colour()
Sets the current text background colour for the DC.
setTextForeground(This, Colour) -> ok
Types:
This = wxDC()
Colour = wx:wx_colour()
Sets the current text foreground colour for the DC.
See: wxMemoryDC, for the interpretation of colours when drawing
into a monochrome bitmap
setUserScale(This, XScale, YScale) -> ok
Types:
This = wxDC()
XScale = YScale = number()
Sets the user scaling factor, useful for applications which
require 'zooming'.
startDoc(This, Message) -> boolean()
Types:
This = wxDC()
Message = unicode:chardata()
Starts a document (only relevant when outputting to a printer).
message is a message to show while printing.
startPage(This) -> ok
Types:
This = wxDC()
Starts a document page (only relevant when outputting to a
printer).
wxWidgets team. wx 2.1.1 wxDC(3)