Copyright | Will Thompson and Iñaki García Etxebarria |
---|---|
License | LGPL-2.1 |
Maintainer | Iñaki García Etxebarria |
Safe Haskell | Safe-Inferred |
Language | Haskell2010 |
Layout managers are delegate classes that handle the preferred size and the allocation of a widget.
You typically subclass GtkLayoutManager
if you want to implement a
layout policy for the children of a widget, or if you want to determine
the size of a widget depending on its contents.
Each GtkWidget
can only have a GtkLayoutManager
instance associated
to it at any given time; it is possible, though, to replace the layout
manager instance using widgetSetLayoutManager
.
Layout properties
A layout manager can expose properties for controlling the layout of
each child, by creating an object type derived from LayoutChild
and installing the properties on it as normal GObject
properties.
Each GtkLayoutChild
instance storing the layout properties for a
specific child is created through the layoutManagerGetLayoutChild
method; a GtkLayoutManager
controls the creation of its GtkLayoutChild
instances by overriding the GtkLayoutManagerClass.create_layout_child()
virtual function. The typical implementation should look like:
c code
static GtkLayoutChild * create_layout_child (GtkLayoutManager *manager, GtkWidget *container, GtkWidget *child) { return g_object_new (your_layout_child_get_type (), "layout-manager", manager, "child-widget", child, NULL); }
The LayoutChild:layoutManager and
LayoutChild:childWidget properties
on the newly created GtkLayoutChild
instance are mandatory. The
GtkLayoutManager
will cache the newly created GtkLayoutChild
instance
until the widget is removed from its parent, or the parent removes the
layout manager.
Each GtkLayoutManager
instance creating a GtkLayoutChild
should use
layoutManagerGetLayoutChild
every time it needs to query
the layout properties; each GtkLayoutChild
instance should call
layoutManagerLayoutChanged
every time a property is
updated, in order to queue a new size measuring and allocation.
Synopsis
- newtype LayoutManager = LayoutManager (ManagedPtr LayoutManager)
- class (GObject o, IsDescendantOf LayoutManager o) => IsLayoutManager o
- toLayoutManager :: (MonadIO m, IsLayoutManager o) => o -> m LayoutManager
- layoutManagerAllocate :: (HasCallStack, MonadIO m, IsLayoutManager a, IsWidget b) => a -> b -> Int32 -> Int32 -> Int32 -> m ()
- layoutManagerGetLayoutChild :: (HasCallStack, MonadIO m, IsLayoutManager a, IsWidget b) => a -> b -> m LayoutChild
- layoutManagerGetRequestMode :: (HasCallStack, MonadIO m, IsLayoutManager a) => a -> m SizeRequestMode
- layoutManagerGetWidget :: (HasCallStack, MonadIO m, IsLayoutManager a) => a -> m (Maybe Widget)
- layoutManagerLayoutChanged :: (HasCallStack, MonadIO m, IsLayoutManager a) => a -> m ()
- layoutManagerMeasure :: (HasCallStack, MonadIO m, IsLayoutManager a, IsWidget b) => a -> b -> Orientation -> Int32 -> m (Int32, Int32, Int32, Int32)
Exported types
newtype LayoutManager Source #
Memory-managed wrapper type.
Instances
Eq LayoutManager Source # | |
Defined in GI.Gtk.Objects.LayoutManager (==) :: LayoutManager -> LayoutManager -> Bool # (/=) :: LayoutManager -> LayoutManager -> Bool # | |
GObject LayoutManager Source # | |
Defined in GI.Gtk.Objects.LayoutManager | |
ManagedPtrNewtype LayoutManager Source # | |
Defined in GI.Gtk.Objects.LayoutManager | |
TypedObject LayoutManager Source # | |
Defined in GI.Gtk.Objects.LayoutManager | |
HasParentTypes LayoutManager Source # | |
Defined in GI.Gtk.Objects.LayoutManager | |
IsGValue (Maybe LayoutManager) Source # | Convert |
Defined in GI.Gtk.Objects.LayoutManager gvalueGType_ :: IO GType # gvalueSet_ :: Ptr GValue -> Maybe LayoutManager -> IO () # gvalueGet_ :: Ptr GValue -> IO (Maybe LayoutManager) # | |
type ParentTypes LayoutManager Source # | |
Defined in GI.Gtk.Objects.LayoutManager |
class (GObject o, IsDescendantOf LayoutManager o) => IsLayoutManager o Source #
Type class for types which can be safely cast to LayoutManager
, for instance with toLayoutManager
.
Instances
(GObject o, IsDescendantOf LayoutManager o) => IsLayoutManager o Source # | |
Defined in GI.Gtk.Objects.LayoutManager |
toLayoutManager :: (MonadIO m, IsLayoutManager o) => o -> m LayoutManager Source #
Cast to LayoutManager
, for types for which this is known to be safe. For general casts, use castTo
.
Methods
Click to display all available methods, including inherited ones
Methods
allocate, bindProperty, bindPropertyFull, forceFloating, freezeNotify, getv, isFloating, layoutChanged, measure, notify, notifyByPspec, ref, refSink, runDispose, stealData, stealQdata, thawNotify, unref, watchClosure.
Getters
getData, getLayoutChild, getProperty, getQdata, getRequestMode, getWidget.
Setters
allocate
layoutManagerAllocate Source #
:: (HasCallStack, MonadIO m, IsLayoutManager a, IsWidget b) | |
=> a |
|
-> b |
|
-> Int32 |
|
-> Int32 |
|
-> Int32 |
|
-> m () |
Assigns the given width
, height
, and baseline
to
a widget
, and computes the position and sizes of the children of
the widget
using the layout management policy of manager
.
getLayoutChild
layoutManagerGetLayoutChild Source #
:: (HasCallStack, MonadIO m, IsLayoutManager a, IsWidget b) | |
=> a |
|
-> b |
|
-> m LayoutChild | Returns: a |
Retrieves a GtkLayoutChild
instance for the GtkLayoutManager
,
creating one if necessary.
The child
widget must be a child of the widget using manager
.
The GtkLayoutChild
instance is owned by the GtkLayoutManager
,
and is guaranteed to exist as long as child
is a child of the
GtkWidget
using the given GtkLayoutManager
.
getRequestMode
layoutManagerGetRequestMode Source #
:: (HasCallStack, MonadIO m, IsLayoutManager a) | |
=> a |
|
-> m SizeRequestMode | Returns: a |
Retrieves the request mode of manager
.
getWidget
layoutManagerGetWidget Source #
:: (HasCallStack, MonadIO m, IsLayoutManager a) | |
=> a |
|
-> m (Maybe Widget) | Returns: a |
Retrieves the GtkWidget
using the given GtkLayoutManager
.
layoutChanged
layoutManagerLayoutChanged Source #
:: (HasCallStack, MonadIO m, IsLayoutManager a) | |
=> a |
|
-> m () |
Queues a resize on the GtkWidget
using manager
, if any.
This function should be called by subclasses of GtkLayoutManager
in response to changes to their layout management policies.
measure
:: (HasCallStack, MonadIO m, IsLayoutManager a, IsWidget b) | |
=> a |
|
-> b |
|
-> Orientation |
|
-> Int32 |
|
-> m (Int32, Int32, Int32, Int32) |
Measures the size of the widget
using manager
, for the
given orientation
and size.
See the Widget
documentation on layout management for
more details.