Graphics.UI.WXCore.Types

An Object a is a pointer to an object of type a. The a parameter is used to encode the inheritance relation. When the type parameter is unit (), it denotes an object of exactly that class, when the parameter is a type variable a, it specifies an object that is at least an instance of that class. For example in wxWindows, we have the following class hierarchy:

 EvtHandler
   |- Window
        |- Frame
        |- Control
            |- Button
            |- Radiobox

In wxHaskell, all the creation functions will return objects of exactly that class and use the () type:

 frameCreate :: Window a -> ... -> IO (Frame ())
 buttonCreate :: Window a -> ... -> IO (Button ())
 ...

In contrast, all the this (or self) pointers of methods can take objects of any instance of that class and have a type variable, for example:

 windowSetClientSize :: Window a -> Size -> IO ()
 controlSetLabel     :: Control a -> String -> IO ()
 buttonSetDefault    :: Button a -> IO ()

This means that we can use windowSetClientSize on any window, including buttons and frames, but we can only use controlSetLabel on controls, not includeing frames.

In wxHaskell, this works since a Frame () is actually a type synonym for Window (CFrame ()) (where CFrame is an abstract data type). We can thus pass a value of type Frame () to anything that expects some Window a. For a button this works too, as it is a synonym for Control (CButton ()) which is in turn a synonym for Window (CControl (CButton ())). Note that we can't pass a frame to something that expects a value of type Control a. Of course, a Window a is actually a type synonym for EvtHandler (CWindow a). If you study the documentation in Graphics.UI.WXH.WxcClasses closely, you can discover where this chain ends :-).

Objects are not automatically deleted. Normally you can use a delete function like windowDelete to delete an object. However, almost all objects in the wxWindows library are automatically deleted by the library. The only objects that should be used with care are resources as bitmaps, fonts and brushes.

Instances

Eq (Object a)

Ord (Object a)

Show (Object a)

objectNull :: Object a

A null object. Use with care.

objectIsNull :: Object a -> Bool

Test for null object.

objectCast :: Object a -> Object b

Cast an object to another type. Use with care.

objectIsManaged :: Object a -> Bool

Is this a managed object.

objectDelete :: WxObject a -> IO ()

Delete a wxObject, works for managed and unmanaged objects.

withObjectPtr :: Object a -> (Ptr a -> IO b) -> IO b

Do something with the object pointer.

withObjectRef :: String -> Object a -> (Ptr a -> IO b) -> IO b

Extract the object pointer and raise an exception if NULL. Otherwise continue with the valid pointer.

withObjectResult :: IO (Ptr a) -> IO (Object a)

Return an unmanaged object.

withManagedObjectResult :: IO (Ptr (TWxObject a)) -> IO (WxObject a)

Create a managed object that will be deleted using |wxObject_SafeDelete|.

objectFinalize :: Object a -> IO ()

Finalize a managed object manually. (no effect on unmanaged objects)

objectNoFinalize :: Object a -> IO ()

Remove the finalizer on a managed object. (no effect on unmanaged objects)

objectFromPtr :: Ptr a -> Object a

Create an unmanaged object.

managedObjectFromPtr :: Ptr (TWxObject a) -> IO (WxObject a)

Create a managed object that will be deleted using |wxObject_SafeDelete|.

Identifiers

type Id = Int

An Id is used to identify objects during event handling.

idAny :: Id

When creating a new window you may specify idAny to let wxWindows assign an unused identifier to it automatically. Furthermore, it can be used in an event connection to handle events for any identifier.

idCreate :: IO Id

Create a new unique identifier.

Bits

(.+.) :: Int -> Int -> Int

Bitwise or of two bit masks.

(.-.) :: Int -> BitFlag -> Int

Unset certain bits in a bitmask.

bits :: [Int] -> Int

Bitwise or of a list of bit masks.

bitsSet :: Int -> Int -> Bool

(bitsSet mask i) tests if all bits in mask are also set in i.

Control

unitIO :: IO a -> IO ()

Ignore the result of an IO action.

bracket

:: IO a	computation to run first (acquire resource)
-> (a -> IO b)	computation to run last (release resource)
-> (a -> IO c)	computation to run in-between (use resource)
-> IO c
Properly release resources, even in the event of an exception.

bracket_

:: IO a	computation to run first (acquire resource)
-> IO b	computation to run last (release resource)
-> IO c	computation to run in-between (use resource)
-> IO c
Specialized variant of `bracket` where the return value is not required.

finally

:: IO a	computation to run first
-> IO b	computation to run last (release resource)
-> IO a
Run some computation afterwards, even if an exception occurs.

finalize

:: IO b	computation to run last (release resource)
-> IO a	computation to run first
-> IO a
Run some computation afterwards, even if an exception occurs. Equals `finally` but with the arguments swapped.

when :: Bool -> IO () -> IO ()

Perform an action when a test succeeds.

Variables

type Var a = IORef a

A mutable variable. Use this instead of MVars or IORefs to accomodate for future expansions with possible concurrency.

varCreate :: a -> IO (Var a)

Create a fresh mutable variable.

varGet :: Var a -> IO a

Get the value of a mutable variable.

varSet :: Var a -> a -> IO ()

Set the value of a mutable variable.

varUpdate :: Var a -> (a -> a) -> IO a

Update the value of a mutable variable and return the old value.

varSwap :: Var a -> a -> IO a

Swap the value of a mutable variable.

Misc.

type Style = Int

A Style is normally used as a flag mask to specify some window style

type EventId = Int

An EventId is identifies specific events.

data TreeItem

Identifies tree items. Note: Replaces the TreeItemId object and takes automatically care of allocation issues.

Instances

Eq TreeItem

Read TreeItem

Show TreeItem

treeItemInvalid :: TreeItem

Invalid tree item.

treeItemIsOk :: TreeItem -> Bool

Is a tree item ok? (i.e. not invalid).

Basic types

Booleans

boolFromInt :: Int -> Bool

intFromBool :: Bool -> Int

Colors

data Color

An abstract data type to define colors.

Instances

Eq Color

Show Color

Typeable Color

rgb :: Int -> Int -> Int -> Color

Create a color from a red/green/blue triple.

colorRGB :: Int -> Int -> Int -> Color

Create a color from a red/green/blue triple.

colorRed :: Color -> Int

Returns a red color component

colorGreen :: Color -> Int

Returns a green color component

colorBlue :: Color -> Int

Returns a blue color component

intFromColor :: Color -> Int

Return an Int where the three least significant bytes contain the red, green, and blue component of a color.

colorFromInt :: Int -> Color

Set the color according to an rgb integer. (see rgbIntFromColor).

colorOk :: Color -> Bool

Check of a color is valid (Colour::Ok)

black :: Color

darkgrey :: Color

dimgrey :: Color

mediumgrey :: Color

grey :: Color

lightgrey :: Color

white :: Color

red :: Color

green :: Color

blue :: Color

cyan :: Color

magenta :: Color

yellow :: Color

System colors

data SystemColor

System Colors.

Constructors

ColorScrollBar	The scrollbar grey area.
ColorBackground	The desktop colour.
ColorActiveCaption	Active window caption.
ColorInactiveCaption	Inactive window caption.
ColorMenu	Menu background.
ColorWindow	Window background.
ColorWindowFrame	Window frame.
ColorMenuText	Menu text.
ColorWindowText	Text in windows.
ColorCaptionText	Text in caption, size box and scrollbar arrow box.
ColorActiveBorder	Active window border.
ColorInactiveBorder	Inactive window border.
ColorAppWorkspace	Background colour MDI -- ^applications.
ColorHighlight	Item(s) selected in a control.
ColorHighlightText	Text of item(s) selected in a control.
ColorBtnFace	Face shading on push buttons.
ColorBtnShadow	Edge shading on push buttons.
ColorGrayText	Greyed (disabled) text.
ColorBtnText	Text on push buttons.
ColorInactiveCaptionText	Colour of text in active captions.
ColorBtnHighlight	Highlight colour for buttons (same as 3DHILIGHT).
Color3DDkShadow	Dark shadow for three-dimensional display elements.
Color3DLight	Light colour for three-dimensional display elements.
ColorInfoText	Text colour for tooltip controls.
ColorInfoBk	Background colour for tooltip controls.
ColorDesktop	Same as BACKGROUND.
Color3DFace	Same as BTNFACE.
Color3DShadow	Same as BTNSHADOW.
Color3DHighlight	Same as BTNHIGHLIGHT.
Color3DHilight	Same as BTNHIGHLIGHT.
ColorBtnHilight	Same as BTNHIGHLIGHT.

Instances

Enum SystemColor

colorSystem :: SystemColor -> Color

Convert a system color to a color.

Points

data Point

A point has an x and y coordinate. Coordinates are normally relative to the upper-left corner of their view frame, where a positive x goes to the right and a positive y to the bottom of the view.

Constructors

Point

pointX :: !Int	x component of a point.
pointY :: !Int	y component of a point.

Instances

point :: Int -> Int -> Point

Construct a point.

pt :: Int -> Int -> Point

Shorter function to construct a point.

pointFromVec :: Vector -> Point

pointFromSize :: Size -> Point

pointZero :: Point

Point at the origin.

pointNull :: Point

A null point is not a legal point (x and y are -1) and can be used for some wxWindows functions to select a default point.

pointMove :: Vector -> Point -> Point

pointMoveBySize :: Point -> Size -> Point

pointAdd :: Point -> Point -> Point

pointSub :: Point -> Point -> Point

pointScale :: Point -> Int -> Point

Sizes

data Size

A Size has a width and height.

Constructors

Size

sizeW :: !Int	the width of a size
sizeH :: !Int	the height of a size

Instances

Eq Size

Show Size

Typeable Size

sz :: Int -> Int -> Size

Short function to construct a size

sizeFromPoint :: Point -> Size

sizeFromVec :: Vector -> Size

sizeZero :: Size

sizeNull :: Size

A null size is not a legal size (width and height are -1) and can be used for some wxWindows functions to select a default size.

sizeEncloses :: Size -> Size -> Bool

Returns True if the first size totally encloses the second argument.

sizeMin :: Size -> Size -> Size

The minimum of two sizes.

sizeMax :: Size -> Size -> Size

The maximum of two sizes.

Vectors

data Vector

A vector with an x and y delta.

Constructors

Vector

vecX :: !Int	delta-x component of a vector
vecY :: !Int	delta-y component of a vector

Instances

vector :: Int -> Int -> Vector

Construct a vector.

vec :: Int -> Int -> Vector

Short function to construct a vector.

vecFromPoint :: Point -> Vector

vecFromSize :: Size -> Vector

vecZero :: Vector

A zero vector

vecNull :: Vector

A null vector has a delta x and y of -1 and can be used for some wxWindows functions to select a default vector.

vecNegate :: Vector -> Vector

vecOrtogonal :: Vector -> Vector

vecAdd :: Vector -> Vector -> Vector

vecSub :: Vector -> Vector -> Vector

vecScale :: Vector -> Int -> Vector

vecBetween :: Point -> Point -> Vector

vecLength :: Vector -> Double

Rectangles

data Rect

A rectangle is defined by the left x coordinate, the top y coordinate, the width and the height.

Constructors

Rect

rectLeft :: !Int
rectTop :: !Int
rectWidth :: !Int
rectHeight :: !Int

Instances

rectTopLeft :: Rect -> Point

rectTopRight :: Rect -> Point

rectBottomLeft :: Rect -> Point

rectBottomRight :: Rect -> Point

rectBottom :: Rect -> Int

rectRight :: Rect -> Int

rect :: Point -> Size -> Rect

Create a rectangle at a certain (upper-left) point with a certain size.

rectBetween :: Point -> Point -> Rect

Construct a (positive) rectangle between two (arbitrary) points.

rectFromSize :: Size -> Rect

Create a rectangle of a certain size with the upper-left corner at (pt 0 0).

rectZero :: Rect

An empty rectangle at (0,0).

rectNull :: Rect

An null rectangle is not a valid rectangle (Rect -1 -1 -1 -1) but can used for some wxWindows functions to select a default rectangle. (i.e. frameCreate).

rectSize :: Rect -> Size

Get the size of a rectangle.

rectIsEmpty :: Rect -> Bool

rectContains :: Rect -> Point -> Bool

rectMoveTo :: Rect -> Point -> Rect

rectFromPoint :: Point -> Rect

rectCentralPoint :: Rect -> Point

rectCentralRect :: Rect -> Size -> Rect

rectStretchTo :: Rect -> Size -> Rect

rectMove :: Rect -> Vector -> Rect

rectOverlaps :: Rect -> Rect -> Bool

rectsDiff :: Rect -> Rect -> [Rect]

A list with rectangles that constitute the difference between two rectangles.

rectUnion :: Rect -> Rect -> Rect

rectOverlap :: Rect -> Rect -> Rect

The intersection between two rectangles.

rectUnions :: [Rect] -> Rect

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