# `wxGraphicsContext` [🔗](https://github.com/erlang/otp/blob/master/lib/wx/src/gen/wxGraphicsContext.erl#L58) A `m:wxGraphicsContext` instance is the object that is drawn upon. It is created by a renderer using `wxGraphicsRenderer:createContext/2`. This can be either directly using a renderer instance, or indirectly using the static convenience `create/1` functions of `m:wxGraphicsContext` that always delegate the task to the default renderer. Remark: For some renderers (like Direct2D or Cairo) processing of drawing operations may be deferred (Direct2D render target normally builds up a batch of rendering commands but defers processing of these commands, Cairo operates on a separate surface) so to make drawing results visible you need to update the content of the context by calling `wxGraphicsContext::Flush()` (not implemented in wx) or by destroying the context. See: * `wxGraphicsRenderer:createContext/2` * `m:wxGCDC` * `m:wxDC` This class is derived, and can use functions, from: * `m:wxGraphicsObject` wxWidgets docs: [wxGraphicsContext](https://docs.wxwidgets.org/3.2/classwx_graphics_context.html) # `wxGraphicsContext` ```elixir -type wxGraphicsContext() :: wx:wx_object(). ``` # `clip` ```elixir -spec clip(This, Region) -> ok when This :: wxGraphicsContext(), Region :: wxRegion:wxRegion(). ``` 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. Remark: * 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/1` 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` ```elixir -spec clip(This, X, Y, W, H) -> ok when This :: wxGraphicsContext(), X :: number(), Y :: number(), W :: number(), H :: number(). ``` This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. # `concatTransform` ```elixir -spec concatTransform(This, Matrix) -> ok when This :: wxGraphicsContext(), Matrix :: wxGraphicsMatrix:wxGraphicsMatrix(). ``` Concatenates the passed in transform with the current transform of this context. # `create` ```elixir -spec create() -> wxGraphicsContext(). ``` Create a lightweight context that can be used only for measuring text. # `create` ```elixir -spec create(WindowDC) -> wxGraphicsContext() when WindowDC :: wxWindowDC:wxWindowDC() | wxWindow:wxWindow() | wxMemoryDC:wxMemoryDC() | wxImage:wxImage(). ``` Creates a `m:wxGraphicsContext` from a `m:wxWindowDC`. See: `wxGraphicsRenderer:createContext/2` # `createBrush` ```elixir -spec createBrush(This, Brush) -> wxGraphicsBrush:wxGraphicsBrush() when This :: wxGraphicsContext(), Brush :: wxBrush:wxBrush(). ``` Creates a native brush from a `m:wxBrush`. # `createFont` ```elixir -spec createFont(This, Font) -> wxGraphicsFont:wxGraphicsFont() when This :: wxGraphicsContext(), Font :: wxFont:wxFont(). ``` # `createFont` ```elixir -spec createFont(This, SizeInPixels, Facename) -> wxGraphicsFont:wxGraphicsFont() when This :: wxGraphicsContext(), SizeInPixels :: number(), Facename :: unicode:chardata(); (This, Font, [Option]) -> wxGraphicsFont:wxGraphicsFont() when This :: wxGraphicsContext(), Font :: wxFont:wxFont(), Option :: {col, wx:wx_colour()}. ``` Creates a native graphics font from a `m:wxFont` and a text colour. Remark: For Direct2D graphics fonts can be created from TrueType fonts only. # `createFont` ```elixir -spec createFont(This, SizeInPixels, Facename, [Option]) -> wxGraphicsFont:wxGraphicsFont() when This :: wxGraphicsContext(), SizeInPixels :: number(), Facename :: unicode:chardata(), Option :: {flags, integer()} | {col, wx:wx_colour()}. ``` Creates a font object with the specified attributes. The use of overload taking `m:wxFont` is preferred, see `wxGraphicsRenderer:createFont/4` for more details. Remark: For Direct2D graphics fonts can be created from TrueType fonts only. Since: 2.9.3 # `createLinearGradientBrush` ```elixir -spec createLinearGradientBrush(This, X1, Y1, X2, Y2, Stops) -> wxGraphicsBrush:wxGraphicsBrush() when This :: wxGraphicsContext(), X1 :: number(), Y1 :: number(), X2 :: number(), Y2 :: number(), Stops :: wxGraphicsGradientStops:wxGraphicsGradientStops(). ``` This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. # `createLinearGradientBrush` ```elixir -spec createLinearGradientBrush(This, X1, Y1, X2, Y2, C1, C2) -> wxGraphicsBrush:wxGraphicsBrush() when This :: wxGraphicsContext(), X1 :: number(), Y1 :: number(), X2 :: number(), Y2 :: number(), C1 :: wx:wx_colour(), C2 :: wx:wx_colour(). ``` ` Creates a native brush with a linear gradient. The brush starts at (@a x1, @a y1) and ends at (@a x2, @a y2). Either just the start and end gradient colours (@a c1 and @a c2) or full set of gradient @a stops can be specified. The version taking wxGraphicsGradientStops is new in wxWidgets 2.9.1. ` The `matrix` parameter was added in wxWidgets 3.1.3 # `createMatrix` ```elixir -spec createMatrix(This) -> wxGraphicsMatrix:wxGraphicsMatrix() when This :: wxGraphicsContext(). ``` # `createMatrix` ```elixir -spec createMatrix(This, [Option]) -> wxGraphicsMatrix:wxGraphicsMatrix() when This :: wxGraphicsContext(), Option :: {a, number()} | {b, number()} | {c, number()} | {d, number()} | {tx, number()} | {ty, number()}. ``` Creates a native affine transformation matrix from the passed in values. The default parameters result in an identity matrix. # `createPath` ```elixir -spec createPath(This) -> wxGraphicsPath:wxGraphicsPath() when This :: wxGraphicsContext(). ``` Creates a native graphics path which is initially empty. # `createPen` ```elixir -spec createPen(This, Pen) -> wxGraphicsPen:wxGraphicsPen() when This :: wxGraphicsContext(), Pen :: wxPen:wxPen(). ``` Creates a native pen from a `m:wxPen`. Prefer to use the overload taking `wxGraphicsPenInfo` (not implemented in wx) unless you already have a `m:wxPen` as constructing one only to pass it to this method is wasteful. # `createRadialGradientBrush` ```elixir -spec createRadialGradientBrush(This, StartX, StartY, EndX, EndY, Radius, Stops) -> wxGraphicsBrush:wxGraphicsBrush() when This :: wxGraphicsContext(), StartX :: number(), StartY :: number(), EndX :: number(), EndY :: number(), Radius :: number(), Stops :: wxGraphicsGradientStops:wxGraphicsGradientStops(). ``` This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. # `createRadialGradientBrush` ```elixir -spec createRadialGradientBrush(This, StartX, StartY, EndX, EndY, Radius, OColor, CColor) -> wxGraphicsBrush:wxGraphicsBrush() when This :: wxGraphicsContext(), StartX :: number(), StartY :: number(), EndX :: number(), EndY :: number(), Radius :: number(), OColor :: wx:wx_colour(), CColor :: wx:wx_colour(). ``` ` Creates a native brush with a radial gradient. The brush originates at (@a startX, @a startY) and ends on a circle around (@a endX, @a endY) with the given @a radius. The gradient may be specified either by its start and end colours @a oColor and @a cColor or by a full set of gradient @a stops. The version taking wxGraphicsGradientStops is new in wxWidgets 2.9.1. ` The ability to apply a transformation matrix to the gradient was added in 3.1.3 # `destroy` ```elixir -spec destroy(This :: wxGraphicsContext()) -> ok. ``` Destroys the object # `drawBitmap` ```elixir -spec drawBitmap(This, Bmp, X, Y, W, H) -> ok when This :: wxGraphicsContext(), Bmp :: wxBitmap:wxBitmap(), X :: number(), Y :: number(), W :: number(), H :: number(). ``` Draws the bitmap. In case of a mono bitmap, this is treated as a mask and the current brushed is used for filling. # `drawEllipse` ```elixir -spec drawEllipse(This, X, Y, W, H) -> ok when This :: wxGraphicsContext(), X :: number(), Y :: number(), W :: number(), H :: number(). ``` Draws an ellipse. # `drawIcon` ```elixir -spec drawIcon(This, Icon, X, Y, W, H) -> ok when This :: wxGraphicsContext(), Icon :: wxIcon:wxIcon(), X :: number(), Y :: number(), W :: number(), H :: number(). ``` Draws the icon. # `drawLines` ```elixir -spec drawLines(This, Points) -> ok when This :: wxGraphicsContext(), Points :: [{X :: float(), Y :: float()}]. ``` # `drawLines` ```elixir -spec drawLines(This, Points, [Option]) -> ok when This :: wxGraphicsContext(), Points :: [{X :: float(), Y :: float()}], Option :: {fillStyle, wx:wx_enum()}. ``` Draws a polygon. # `drawPath` ```elixir -spec drawPath(This, Path) -> ok when This :: wxGraphicsContext(), Path :: wxGraphicsPath:wxGraphicsPath(). ``` # `drawPath` ```elixir -spec drawPath(This, Path, [Option]) -> ok when This :: wxGraphicsContext(), Path :: wxGraphicsPath:wxGraphicsPath(), Option :: {fillStyle, wx:wx_enum()}. ``` Draws the path by first filling and then stroking. # `drawRectangle` ```elixir -spec drawRectangle(This, X, Y, W, H) -> ok when This :: wxGraphicsContext(), X :: number(), Y :: number(), W :: number(), H :: number(). ``` Draws a rectangle. # `drawRoundedRectangle` ```elixir -spec drawRoundedRectangle(This, X, Y, W, H, Radius) -> ok when This :: wxGraphicsContext(), X :: number(), Y :: number(), W :: number(), H :: number(), Radius :: number(). ``` Draws a rounded rectangle. # `drawText` ```elixir -spec drawText(This, Str, X, Y) -> ok when This :: wxGraphicsContext(), Str :: unicode:chardata(), X :: number(), Y :: number(). ``` Draws text at the defined position. # `drawText` ```elixir -spec drawText(This, Str, X, Y, Angle) -> ok when This :: wxGraphicsContext(), Str :: unicode:chardata(), X :: number(), Y :: number(), Angle :: number(); (This, Str, X, Y, BackgroundBrush) -> ok when This :: wxGraphicsContext(), Str :: unicode:chardata(), X :: number(), Y :: number(), BackgroundBrush :: wxGraphicsBrush:wxGraphicsBrush(). ``` Draws text at the defined position. # `drawText` ```elixir -spec drawText(This, Str, X, Y, Angle, BackgroundBrush) -> ok when This :: wxGraphicsContext(), Str :: unicode:chardata(), X :: number(), Y :: number(), Angle :: number(), BackgroundBrush :: wxGraphicsBrush:wxGraphicsBrush(). ``` Draws text at the defined position. # `fillPath` ```elixir -spec fillPath(This, Path) -> ok when This :: wxGraphicsContext(), Path :: wxGraphicsPath:wxGraphicsPath(). ``` # `fillPath` ```elixir -spec fillPath(This, Path, [Option]) -> ok when This :: wxGraphicsContext(), Path :: wxGraphicsPath:wxGraphicsPath(), Option :: {fillStyle, wx:wx_enum()}. ``` Fills the path with the current brush. # `getPartialTextExtents` ```elixir -spec getPartialTextExtents(This, Text) -> [number()] when This :: wxGraphicsContext(), Text :: unicode:chardata(). ``` Fills the `widths` array with the widths from the beginning of `text` to the corresponding character of `text`. # `getTextExtent` ```elixir -spec getTextExtent(This, Text) -> Result when Result :: {Width :: number(), Height :: number(), Descent :: number(), ExternalLeading :: number()}, This :: wxGraphicsContext(), Text :: unicode:chardata(). ``` Gets the dimensions of the string using the currently selected font. # `getTransform` ```elixir -spec getTransform(This) -> wxGraphicsMatrix:wxGraphicsMatrix() when This :: wxGraphicsContext(). ``` Gets the current transformation matrix of this context. # `resetClip` ```elixir -spec resetClip(This) -> ok when This :: wxGraphicsContext(). ``` Resets the clipping to original shape. # `rotate` ```elixir -spec rotate(This, Angle) -> ok when This :: wxGraphicsContext(), Angle :: number(). ``` Rotates the current transformation matrix (in radians). # `scale` ```elixir -spec scale(This, XScale, YScale) -> ok when This :: wxGraphicsContext(), XScale :: number(), YScale :: number(). ``` Scales the current transformation matrix. # `setBrush` ```elixir -spec setBrush(This, Brush) -> ok when This :: wxGraphicsContext(), Brush :: wxGraphicsBrush:wxGraphicsBrush() | wxBrush:wxBrush(). ``` Sets the brush for filling paths. # `setFont` ```elixir -spec setFont(This, Font) -> ok when This :: wxGraphicsContext(), Font :: wxGraphicsFont:wxGraphicsFont(). ``` Sets the font for drawing text. # `setFont` ```elixir -spec setFont(This, Font, Colour) -> ok when This :: wxGraphicsContext(), Font :: wxFont:wxFont(), Colour :: wx:wx_colour(). ``` Sets the font for drawing text. Remark: For Direct2D only TrueType fonts can be used. # `setPen` ```elixir -spec setPen(This, Pen) -> ok when This :: wxGraphicsContext(), Pen :: wxPen:wxPen() | wxGraphicsPen:wxGraphicsPen(). ``` Sets the pen used for stroking. # `setTransform` ```elixir -spec setTransform(This, Matrix) -> ok when This :: wxGraphicsContext(), Matrix :: wxGraphicsMatrix:wxGraphicsMatrix(). ``` Sets the current transformation matrix of this context. # `strokeLine` ```elixir -spec strokeLine(This, X1, Y1, X2, Y2) -> ok when This :: wxGraphicsContext(), X1 :: number(), Y1 :: number(), X2 :: number(), Y2 :: number(). ``` Strokes a single line. # `strokeLines` ```elixir -spec strokeLines(This, Points) -> ok when This :: wxGraphicsContext(), Points :: [{X :: float(), Y :: float()}]. ``` Stroke lines connecting all the points. Unlike the other overload of this function, this method draws a single polyline and not a number of disconnected lines. # `strokePath` ```elixir -spec strokePath(This, Path) -> ok when This :: wxGraphicsContext(), Path :: wxGraphicsPath:wxGraphicsPath(). ``` Strokes along a path with the current pen. # `translate` ```elixir -spec translate(This, Dx, Dy) -> ok when This :: wxGraphicsContext(), Dx :: number(), Dy :: number(). ``` Translates the current transformation matrix. --- *Consult [api-reference.md](api-reference.md) for complete listing*