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| Graphics.SOE | | Portability | non-portable (requires concurrency) | | Stability | stable | | Maintainer | libraries@haskell.org |
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| Description |
The graphics library used in The Haskell School of Expression,
by Paul Hudak, cf http://www.haskell.org/soe/.
Notes:
- This module is called SOEGraphics in the book. It is a cut
down version of Graphics.HGL, with the interface frozen to match
the book.
- In chapters 13, 17 and 19 of the book, there are imports of modules
Win32Misc and Word. These should be omitted, as timeGetTime
and word32ToInt are provided by this module.
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| Synopsis |
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| Getting started
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| runGraphics :: IO () -> IO () |
| Initialize the system to do graphics, run an action while collecting
user interface events and forwarding them to the action, and then clean
up everything else at the end.
The other functions of the library may only be used inside runGraphics.
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| Windows
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| type Title = String |
| Title of a window.
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| type Size = (Int, Int) |
| A (width, height) pair, both measured in pixels.
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| data Window |
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| openWindow :: Title -> Size -> IO Window |
| Create a window with the given title and size.
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| getWindowSize :: Window -> IO Size |
| The current size of the window.
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| clearWindow :: Window -> IO () |
| Erase all drawing in the window.
(That is, set the Graphic held by the window to emptyGraphic.)
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| drawInWindow :: Window -> Graphic -> IO () |
| Draw the given graphic on the window, on top of anything that is
already there.
(That is, combine the given Graphic and the one held by the window
using overGraphic, store the result in the window, and display it.)
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| drawInWindowNow :: Window -> Graphic -> IO () |
| Another name for drawInWindow, retained for backwards compatibility.
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| setGraphic :: Window -> Graphic -> IO () |
| Set the current drawing in a window.
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| closeWindow :: Window -> IO () |
| Close the window.
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| General windows
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| openWindowEx |
| :: Title | the title of the window
| | -> Maybe Point | the initial position of the window
| | -> Maybe Size | the initial size of the window
| | -> RedrawMode | how to display a graphic on the window
| | -> Maybe Word32 | optionally attach a timer to the window,
with the specified time (in milliseconds)
between ticks.
| | -> IO Window | | | an extended version of openWindow.
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| data RedrawMode |
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| drawGraphic :: RedrawMode |
| Draw directly to the window
(slightly faster than drawBufferedGraphic, but more prone to flicker).
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| drawBufferedGraphic :: RedrawMode |
| Use a double buffer to reduce flicker and thus improve the look
of animations.
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| Drawing
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| type Graphic = Draw () |
| An abstract representation of an image.
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| emptyGraphic :: Graphic |
| An empty drawing.
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| overGraphic :: Graphic -> Graphic -> Graphic |
| A composite drawing made by overlaying the first argument on the second.
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| overGraphics :: [Graphic] -> Graphic |
| Overlay a list of drawings.
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| Color
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| data Color |
| Named colors.
| | Constructors | | Black | | | Blue | | | Green | | | Cyan | | | Red | | | Magenta | | | Yellow | | | White | |
|  Instances | |
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| withColor :: Color -> Graphic -> Graphic |
| Set the default drawing color for a Graphic.
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| Drawing text
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| text :: Point -> String -> Graphic |
| Render a String positioned relative to the specified Point.
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| Drawing shapes
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| type Point = (Int, Int) |
| A position within a window, measured in pixels to the right and down
from the top left corner.
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| ellipse |
| :: Point | a corner of the rectangle bounding the ellipse.
| | -> Point | the opposite corner of the rectangle bounding the ellipse.
| | -> Graphic | a filled shape
| | A filled ellipse that fits inside a rectangle defined by two
Points on the window.
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| shearEllipse |
| :: Point | a corner of the bounding parallelogram.
| | -> Point | another corner of the parallelogram, adjacent to the first.
| | -> Point | another corner of the parallelogram, adjacent to the first
and thus opposite to the second.
| | -> Graphic | a filled shape
| | A filled sheared ellipse that fits inside a parallelogram defined
by three Points on the window. This function is implemented using
polygons on both Win32 and X11.
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| line :: Point -> Point -> Graphic |
| A line between two Points.
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| polygon :: [Point] -> Graphic |
| A filled polygon defined by a list of Points.
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| polyline :: [Point] -> Graphic |
| A series of lines through a list of Points.
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| polyBezier :: [Point] -> Graphic |
| A series of (unfilled) Bezier curves defined by a list of 3n+1
control Points. This function is not supported on X11 (it yields
an error message and a polyline).
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| type Angle = Double |
| An angle in degrees (0 to 360).
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| arc |
| :: Point | a corner of the rectangle bounding the ellipse.
| | -> Point | the opposite corner of the rectangle bounding the ellipse.
| | -> Angle | the start angle of the arc, measured counter-clockwise
from the horizontal.
| | -> Angle | the extent of the arc, measured counter-clockwise from
the start angle.
| | -> Graphic | a filled shape
| | A filled arc from an ellipse.
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| Regions
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| data Region |
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| createRectangle :: Point -> Point -> Region |
| A rectangular region, with the given points as opposite corners.
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| createEllipse :: Point -> Point -> Region |
| An elliptical region that fits in the rectangle with the given points
as opposite corners.
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| createPolygon :: [Point] -> Region |
| A polygonal region defined by a list of Points.
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| andRegion :: Region -> Region -> Region |
| The intersection of two regions.
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| orRegion :: Region -> Region -> Region |
| The union of two regions.
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| xorRegion :: Region -> Region -> Region |
| The symmetric difference of two regions.
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| diffRegion :: Region -> Region -> Region |
| The part of the first region that is not also in the second.
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| drawRegion :: Region -> Graphic |
| Draw a Region in the current color.
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| User interaction
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| Keyboard events
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| getKey :: Window -> IO Char |
| Wait until a key is pressed and released,
and return the corresponding character.
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| Mouse events
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| getLBP :: Window -> IO Point |
| Wait for a press of the left mouse button,
and return the position of the mouse cursor.
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| getRBP :: Window -> IO Point |
| Wait for a press of the right mouse button,
and return the position of the mouse cursor.
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| General events
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| data Event |
| User interface events
| | Constructors | | Key | occurs when a key was pressed or released.
| | char :: Char | character corresponding to the key
| | isDown :: Bool | if True, the key was pressed;
otherwise it was released
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| | Button | occurs when a mouse button is pressed or released.
| | pt :: Point | the position of the mouse cursor
| | isLeft :: Bool | if True, it was the left button
| | isDown :: Bool | if True, the button was pressed;
otherwise it was released
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| | MouseMove | occurs when the mouse is moved inside the window.
| | pt :: Point | the position of the mouse cursor
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| | Resize | occurs when the window is resized.
The new window size can be discovered using
getWindowSize.
| | Closed | occurs when the window is closed.
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| | Instances | |
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| maybeGetWindowEvent :: Window -> IO (Maybe Event) |
| Return a pending eventin the window, if any.
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| getWindowEvent :: Window -> IO Event |
| Wait for the next event in the window.
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| Time
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| Word32 |
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| getWindowTick :: Window -> IO () |
| Wait for the next tick event from the timer on the given window.
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| timeGetTime :: IO Word32 |
| The current time of day (in milliseconds).
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| word32ToInt :: Word32 -> Int |
| An obsolete special case of fromIntegral.
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| Produced by Haddock version 0.8 |
