Graphics.UI.Gtk.Gdk.DrawWindow

A DrawWindow is a rectangular region on the screen.

Class Hierarchy

 | GObject
 | +----Drawable
 | +----DrawWindow

Types

data DrawWindow

Instances

Eq DrawWindow

Ord DrawWindow

GObjectClass DrawWindow

DrawWindowClass DrawWindow

DrawableClass DrawWindow

class DrawableClass o => DrawWindowClass o

Instances

DrawWindowClass DrawWindow

castToDrawWindow :: GObjectClass obj => obj -> DrawWindow

gTypeDrawWindow :: GType

data WindowState

The state a DrawWindow is in.

Constructors

WindowStateWithdrawn

WindowStateIconified

WindowStateMaximized

WindowStateSticky

WindowStateFullscreen

WindowStateAbove

WindowStateBelow

Instances

Bounded WindowState

Enum WindowState

These are hints for the window manager that indicate what type of function the window has. The window manager can use this when determining decoration and behaviour of the window. The hint must be set before mapping the window.

See the extended window manager hints specification for more details about window types.

Eq WindowState

Show WindowState

Flags WindowState

data NativeWindowId

The identifer of a window of the underlying windowing system.

Instances

Eq NativeWindowId

Show NativeWindowId

toNativeWindowId :: Integral a => a -> NativeWindowId

fromNativeWindowId :: Integral a => NativeWindowId -> a

Methods

drawWindowGetState

Arguments

:: DrawWindowClass self

=> self

-> IO [WindowState]

returns DrawWindow flags

Gets the bitwise OR of the currently active drawWindow state flags, from the WindowState enumeration.

drawWindowScroll

Arguments

:: DrawWindowClass self

=> self

-> Int

dx - Amount to scroll in the X direction

-> Int

dy - Amount to scroll in the Y direction

-> IO ()

Scroll the contents of DrawWindow.

• Scroll both, pixels and children, by the given amount. DrawWindow itself does not move. Portions of the window that the scroll operation brings inm from offscreen areas are invalidated. The invalidated region may be bigger than what would strictly be necessary. (For X11, a minimum area will be invalidated if the window has no subwindows, or if the edges of the window's parent do not extend beyond the edges of the drawWindow. In other cases, a multi-step process is used to scroll the window which may produce temporary visual artifacts and unnecessary invalidations.)

drawWindowClear :: DrawWindowClass self => self -> IO ()

Clears an entire DrawWindow to the background color or background pixmap.

drawWindowClearArea

Arguments

:: DrawWindowClass self

=> self

-> Int

x - x coordinate of rectangle to clear

-> Int

y - y coordinate of rectangle to clear

-> Int

width - width of rectangle to clear

-> Int

height - height of rectangle to clear

-> IO ()

Clears an area of DrawWindow to the background color or background pixmap.

drawWindowClearAreaExpose

Arguments

:: DrawWindowClass self

=> self

-> Int

x - x coordinate of rectangle to clear

-> Int

y - y coordinate of rectangle to clear

-> Int

width - width of rectangle to clear

-> Int

height - height of rectangle to clear

-> IO ()

Like drawWindowClearArea, but also generates an expose event for the cleared area.

drawWindowRaise :: DrawWindowClass self => self -> IO ()

Raises DrawWindow to the top of the Z-order (stacking order), so that other drawWindows with the same parent drawWindow appear below DrawWindow. This is true whether or not the drawWindows are visible.

If DrawWindow is a toplevel, the window manager may choose to deny the request to move the drawWindow in the Z-order, drawWindowRaise only requests the restack, does not guarantee it.

drawWindowLower :: DrawWindowClass self => self -> IO ()

Lowers DrawWindow to the bottom of the Z-order (stacking order), so that other windows with the same parent window appear above DrawWindow. This is true whether or not the other windows are visible.

If DrawWindow is a toplevel, the window manager may choose to deny the request to move the drawWindow in the Z-order, drawWindowLower only requests the restack, does not guarantee it.

Note that a widget is raised automatically when it is mapped, thus you need to call drawWindowLower after widgetShow if the window should not appear above other windows.

drawWindowBeginPaintRect

Arguments

:: DrawWindowClass self

=> self

-> Rectangle

rectangle - rectangle you intend to draw to

-> IO ()

A convenience wrapper around drawWindowBeginPaintRegion which creates a rectangular region for you.

• See drawWindowBeginPaintRegion for details.

drawWindowBeginPaintRegion

Arguments

:: DrawWindowClass self

=> self

-> Region

region - region you intend to draw to

-> IO ()

Indicate that you are beginning the process of redrawing region.

• A backing store (offscreen buffer) large enough to contain region will be created. The backing store will be initialized with the background color or background pixmap for DrawWindow. Then, all drawing operations performed on DrawWindow will be diverted to the backing store. When you call drawWindowEndPaint, the backing store will be copied to DrawWindow, making it visible onscreen. Only the part of DrawWindow contained in region will be modified; that is, drawing operations are clipped to region.

The net result of all this is to remove flicker, because the user sees the finished product appear all at once when you call drawWindowEndPaint. If you draw to DrawWindow directly without calling drawWindowBeginPaintRegion, the user may see flicker as individual drawing operations are performed in sequence. The clipping and background-initializing features of drawWindowBeginPaintRegion are conveniences for the programmer, so you can avoid doing that work yourself.

When using GTK+, the widget system automatically places calls to drawWindowBeginPaintRegion and drawWindowEndPaint around emissions of the expose_event signal. That is, if you're writing an expose event handler, you can assume that the exposed area in eventRegion has already been cleared to the window background, is already set as the clip region, and already has a backing store. Therefore in most cases, application code need not call drawWindowBeginPaintRegion. (You can disable the automatic calls around expose events on a widget-by-widget basis by calling widgetSetDoubleBuffered.)

If you call this function multiple times before calling the matching drawWindowEndPaint, the backing stores are pushed onto a stack. drawWindowEndPaint copies the topmost backing store onscreen, subtracts the topmost region from all other regions in the stack, and pops the stack. All drawing operations affect only the topmost backing store in the stack. One matching call to drawWindowEndPaint is required for each call to drawWindowBeginPaintRegion.

drawWindowEndPaint :: DrawWindowClass self => self -> IO ()

Signal that drawing has finished.

• Indicates that the backing store created by the most recent call to drawWindowBeginPaintRegion should be copied onscreen and deleted, leaving the next-most-recent backing store or no backing store at all as the active paint region. See drawWindowBeginPaintRegion for full details. It is an error to call this function without a matching drawWindowBeginPaintRegion first.

drawWindowInvalidateRect

Arguments

:: DrawWindowClass self

=> self

-> Rectangle

rect - rectangle to invalidate

-> Bool

invalidateChildren - whether to also invalidate child drawWindows

-> IO ()

A convenience wrapper around drawWindowInvalidateRegion which invalidates a rectangular region. See drawWindowInvalidateRegion for details.

drawWindowInvalidateRegion

Arguments

:: DrawWindowClass self

=> self

-> Region

region - a Region

-> Bool

invalidateChildren - True to also invalidate child drawWindows

-> IO ()

Adds region to the update area for DrawWindow. The update area is the region that needs to be redrawn, or "dirty region.". During the next idle period of the main look, an expose even for this region will be created. An application would normally redraw the contents of DrawWindow in response to those expose events.

The invalidateChildren parameter controls whether the region of each child drawWindow that intersects region will also be invalidated. If False, then the update area for child drawWindows will remain unaffected.

drawWindowGetUpdateArea

Arguments

:: DrawWindowClass self

=> self

-> IO (Maybe Region)

returns the update area for DrawWindow

Ask for the dirty region of this window.

• Transfers ownership of the update area from DrawWindow to the caller of the function. That is, after calling this function, DrawWindow will no longer have an invalid/dirty region; the update area is removed from DrawWindow and handed to you. If this window has no update area, drawWindowGetUpdateArea returns Nothing.

drawWindowFreezeUpdates :: DrawWindowClass self => self -> IO ()

Temporarily freezes a drawWindow such that it won't receive expose events. * The drawWindow will begin receiving expose events again when drawWindowThawUpdates is called. If drawWindowFreezeUpdates has been called more than once, drawWindowThawUpdates must be called an equal number of times to begin processing exposes.

drawWindowThawUpdates :: DrawWindowClass self => self -> IO ()

Thaws a drawWindow frozen with drawWindowFreezeUpdates.

drawWindowProcessUpdates

Arguments

:: DrawWindowClass self

=> self

-> Bool

updateChildren - whether to also process updates for child drawWindows

-> IO ()

Sends one or more expose events to DrawWindow.

• The areas in each expose event will cover the entire update area for the window (see drawWindowInvalidateRegion for details). Normally Gtk calls drawWindowProcessUpdates on your behalf, so there's no need to call this function unless you want to force expose events to be delivered immediately and synchronously (vs. the usual case, where Gtk delivers them in an idle handler). Occasionally this is useful to produce nicer scrolling behavior, for example.

drawWindowSetAcceptFocus

Arguments

:: DrawWindowClass self

=> self

-> Bool

acceptFocus - True if the drawWindow should receive input focus

-> IO ()

Setting acceptFocus to False hints the desktop environment that the window doesn't want to receive input focus.

On X, it is the responsibility of the drawWindow manager to interpret this hint. ICCCM-compliant drawWindow manager usually respect it.

• Available since Gdk version 2.4

drawWindowShapeCombineMask

Arguments

:: DrawWindowClass self

=> self

-> Maybe Pixmap

mask - region of drawWindow to be non-transparent

-> Int

offsetX - X position of shapeRegion in DrawWindow coordinates

-> Int

offsetY - Y position of shapeRegion in DrawWindow coordinates

-> IO ()

Applies a shape mask to window. Pixels in window corresponding to set bits in the mask will be visible; pixels in window corresponding to unset bits in the mask will be transparent. This gives a non-rectangular window.

• If mask is Nothing, the shape mask will be unset, and the x/y parameters are not used. The mask must be a bitmap, that is, a Pixmap of depth one.
• On the X11 platform, this uses an X server extension which is widely available on most common platforms, but not available on very old X servers, and occasionally the implementation will be buggy. On servers without the shape extension, this function will do nothing. On the Win32 platform the functionality is always present.
• This function works on both toplevel and child windows.

drawWindowShapeCombineRegion

Arguments

:: DrawWindowClass self

=> self

-> Maybe Region

shapeRegion - region of drawWindow to be non-transparent

-> Int

offsetX - X position of shapeRegion in DrawWindow coordinates

-> Int

offsetY - Y position of shapeRegion in DrawWindow coordinates

-> IO ()

Makes pixels in DrawWindow outside shapeRegion transparent.

• Makes pixels in DrawWindow outside shapeRegion transparent, so that the window may be nonrectangular.

If shapeRegion is Nothing, the shape will be unset, so the whole DrawWindow will be opaque again. The parameters offsetX and offsetY are ignored if shapeRegion is Nothing.

On the X11 platform, this uses an X server extension which is widely available on most common platforms, but not available on very old X servers, and occasionally the implementation will be buggy. On servers without the shape extension, this function will do nothing.

This function works on both toplevel and child drawWindows.

drawWindowSetChildShapes :: DrawWindowClass self => self -> IO ()

Sets the shape mask of DrawWindow to the union of shape masks for all children of DrawWindow, ignoring the shape mask of DrawWindow itself. Contrast with drawWindowMergeChildShapes which includes the shape mask of DrawWindow in the masks to be merged.

drawWindowMergeChildShapes :: DrawWindowClass self => self -> IO ()

Merges the shape masks for any child drawWindows into the shape mask for DrawWindow. i.e. the union of all masks for DrawWindow and its children will become the new mask for DrawWindow. See drawWindowShapeCombineMask.

This function is distinct from drawWindowSetChildShapes because it includes DrawWindow's shape mask in the set of shapes to be merged.

drawWindowGetPointer :: DrawWindowClass self => self -> IO (Maybe (Bool, Int, Int, [Modifier]))

drawWindowGetPointerPos :: DrawWindowClass self => self -> IO (Maybe DrawWindow, Int, Int, [Modifier])

Obtains the current pointer position and modifier state.

• The position is given in coordinates relative to the given window.
• The return value is (Just win, x, y, mod) where win is the window over which the mouse currently resides and mod denotes the keyboard modifiers currently being depressed.
• The return value is Nothing for the window if the mouse cursor is not over a known window.

drawWindowGetOrigin

Arguments

:: DrawWindow

-> IO (Int, Int)

(x, y)

Obtains the position of a window in screen coordinates.

You can use this to help convert a position between screen coordinates and local DrawWindow relative coordinates.

drawWindowSetCursor :: DrawWindow -> Maybe Cursor -> IO ()

Sets the mouse pointer for a DrawWindow.

Use cursorNewForDisplay or cursorNewFromPixmap to create the cursor. To make the cursor invisible, use BlankCursor. Passing Nothing means that the DrawWindow will use the cursor of its parent DrawWindow. Most DrawWindow should use this default.

drawWindowForeignNew :: NativeWindowId -> IO (Maybe DrawWindow)

Get the handle to an exising window of the windowing system. The passed-in handle is a reference to a native window, that is, an Xlib XID for X windows and a HWND for Win32.

drawWindowGetDefaultRootWindow

Arguments

:: IO DrawWindow

returns the default root window

Obtains the root window (parent all other windows are inside) for the default display and screen.