Trait gtk4::subclass::cell_area_context::CellAreaContextImpl
source · pub trait CellAreaContextImpl: CellAreaContextImplExt + ObjectImpl {
// Provided methods
fn reset(&self) { ... }
fn preferred_height_for_width(&self, width: i32) -> (i32, i32) { ... }
fn preferred_width_for_height(&self, height: i32) -> (i32, i32) { ... }
fn allocate(&self, width: i32, height: i32) { ... }
}Provided Methods§
sourcefn reset(&self)
fn reset(&self)
Resets any previously cached request and allocation data.
When underlying TreeModel data changes its
important to reset the context if the content
size is allowed to shrink. If the content size
is only allowed to grow (this is usually an option
for views rendering large data stores as a measure
of optimization), then only the row that changed
or was inserted needs to be (re)requested with
gtk_cell_area_get_preferred_width().
When the new overall size of the context requires that the allocated size changes (or whenever this allocation changes at all), the variable row sizes need to be re-requested for every row.
For instance, if the rows are displayed all with the same width from top to bottom then a change in the allocated width necessitates a recalculation of all the displayed row heights using gtk_cell_area_get_preferred_height_for_width().
Deprecated since 4.10
This object will be removed in GTK 5
sourcefn preferred_height_for_width(&self, width: i32) -> (i32, i32)
fn preferred_height_for_width(&self, width: i32) -> (i32, i32)
Gets the accumulative preferred height for @width for all rows which have been requested for the same said @width with this context.
After gtk_cell_area_context_reset() is called and/or before ever
requesting the size of a CellArea, the returned values are -1.
Deprecated since 4.10
This object will be removed in GTK 5
width
a proposed width for allocation
Returns
minimum_height
location to store the minimum height
natural_height
location to store the natural height
sourcefn preferred_width_for_height(&self, height: i32) -> (i32, i32)
fn preferred_width_for_height(&self, height: i32) -> (i32, i32)
Gets the accumulative preferred width for @height for all rows which have been requested for the same said @height with this context.
After gtk_cell_area_context_reset() is called and/or before ever
requesting the size of a CellArea, the returned values are -1.
Deprecated since 4.10
This object will be removed in GTK 5
height
a proposed height for allocation
Returns
minimum_width
location to store the minimum width
natural_width
location to store the natural width
sourcefn allocate(&self, width: i32, height: i32)
fn allocate(&self, width: i32, height: i32)
Allocates a width and/or a height for all rows which are to be rendered with @self.
Usually allocation is performed only horizontally or sometimes
vertically since a group of rows are usually rendered side by
side vertically or horizontally and share either the same width
or the same height. Sometimes they are allocated in both horizontal
and vertical orientations producing a homogeneous effect of the
rows. This is generally the case for TreeView when
GtkTreeView:fixed-height-mode is enabled.
Deprecated since 4.10
This object will be removed in GTK 5
width
the allocated width for all TreeModel rows rendered
with @self, or -1
height
the allocated height for all TreeModel rows rendered
with @self, or -1