Class: Gtk::CellAreaContext

Inherits:
Object
  • Object
show all
Defined in:
(unknown)

Instance Method Summary collapse

Instance Method Details

#allocate(width, height) ⇒ nil

Allocates a width and/or a height for all rows which are to be
rendered with context.

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 GtkTreeView when
GtkTreeView:fixed-height-mode is enabled.

Parameters:

  • width (Integer) —

    the allocated width for all GtkTreeModel rows rendered
    with context, or -1

  • height (Integer) —

    the allocated height for all GtkTreeModel rows rendered
    with context, or -1

Returns:

  • (nil)

#area ⇒ Gtk::CellArea

The GtkCellArea this context was created by

Returns:

#area=(area) ⇒ Gtk::CellArea

The GtkCellArea this context was created by

Parameters:

Returns:

#get_allocation(width, height) ⇒ nil

Fetches the current allocation size for context.

If the context was not allocated in width or height, or if the
context was recently reset with gtk_cell_area_context_reset(),
the returned value will be -1.

Parameters:

  • width (Integer) —

    location to store the allocated width

  • height (Integer) —

    location to store the allocated height

Returns:

  • (nil)

#get_preferred_height(minimum_height, natural_height) ⇒ nil

Gets the accumulative preferred height for all rows which have been
requested with this context.

After gtk_cell_area_context_reset() is called and/or before ever
requesting the size of a GtkCellArea, the returned values are 0.

Parameters:

  • minimum_height (Integer) —

    location to store the minimum height

  • natural_height (Integer) —

    location to store the natural height

Returns:

  • (nil)

#get_preferred_height_for_width(width, minimum_height, natural_height) ⇒ nil

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 GtkCellArea, the returned values are -1.

Parameters:

  • width (Integer) —

    a proposed width for allocation

  • minimum_height (Integer) —

    location to store the minimum height

  • natural_height (Integer) —

    location to store the natural height

Returns:

  • (nil)

#get_preferred_width(minimum_width, natural_width) ⇒ nil

Gets the accumulative preferred width for all rows which have been
requested with this context.

After gtk_cell_area_context_reset() is called and/or before ever
requesting the size of a GtkCellArea, the returned values are 0.

Parameters:

  • minimum_width (Integer) —

    location to store the minimum width

  • natural_width (Integer) —

    location to store the natural width

Returns:

  • (nil)

#get_preferred_width_for_height(height, minimum_width, natural_width) ⇒ nil

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 GtkCellArea, the returned values are -1.

Parameters:

  • height (Integer) —

    a proposed height for allocation

  • minimum_width (Integer) —

    location to store the minimum width

  • natural_width (Integer) —

    location to store the natural width

Returns:

  • (nil)

#minimum_height ⇒ Integer

The minimum height for the GtkCellArea in this context
for all GtkTreeModel rows that this context was requested
for using gtk_cell_area_get_preferred_height().

Returns:

  • (Integer) —

    minimum-height

#minimum_height=(minimum_height) ⇒ Integer

The minimum height for the GtkCellArea in this context
for all GtkTreeModel rows that this context was requested
for using gtk_cell_area_get_preferred_height().

Parameters:

  • minimum_height (Integer)

Returns:

  • (Integer) —

    minimum-height

  • (Integer) —

    minimum-height

#minimum_width ⇒ Integer

The minimum width for the GtkCellArea in this context
for all GtkTreeModel rows that this context was requested
for using gtk_cell_area_get_preferred_width().

Returns:

  • (Integer) —

    minimum-width

#minimum_width=(minimum_width) ⇒ Integer

The minimum width for the GtkCellArea in this context
for all GtkTreeModel rows that this context was requested
for using gtk_cell_area_get_preferred_width().

Parameters:

  • minimum_width (Integer)

Returns:

  • (Integer) —

    minimum-width

  • (Integer) —

    minimum-width

#natural_height ⇒ Integer

The natural height for the GtkCellArea in this context
for all GtkTreeModel rows that this context was requested
for using gtk_cell_area_get_preferred_height().

Returns:

  • (Integer) —

    natural-height

#natural_height=(natural_height) ⇒ Integer

The natural height for the GtkCellArea in this context
for all GtkTreeModel rows that this context was requested
for using gtk_cell_area_get_preferred_height().

Parameters:

  • natural_height (Integer)

Returns:

  • (Integer) —

    natural-height

  • (Integer) —

    natural-height

#natural_width ⇒ Integer

The natural width for the GtkCellArea in this context
for all GtkTreeModel rows that this context was requested
for using gtk_cell_area_get_preferred_width().

Returns:

  • (Integer) —

    natural-width

#natural_width=(natural_width) ⇒ Integer

The natural width for the GtkCellArea in this context
for all GtkTreeModel rows that this context was requested
for using gtk_cell_area_get_preferred_width().

Parameters:

  • natural_width (Integer)

Returns:

  • (Integer) —

    natural-width

  • (Integer) —

    natural-width

#push_preferred_height(minimum_height, natural_height) ⇒ nil

Causes the minimum and/or natural height to grow if the new
proposed sizes exceed the current minimum and natural height.

This is used by GtkCellAreaContext implementations during
the request process over a series of GtkTreeModel rows to
progressively push the requested height over a series of
gtk_cell_area_get_preferred_height() requests.

Parameters:

  • minimum_height (Integer) —

    the proposed new minimum height for context

  • natural_height (Integer) —

    the proposed new natural height for context

Returns:

  • (nil)

#push_preferred_width(minimum_width, natural_width) ⇒ nil

Causes the minimum and/or natural width to grow if the new
proposed sizes exceed the current minimum and natural width.

This is used by GtkCellAreaContext implementations during
the request process over a series of GtkTreeModel rows to
progressively push the requested width over a series of
gtk_cell_area_get_preferred_width() requests.

Parameters:

  • minimum_width (Integer) —

    the proposed new minimum width for context

  • natural_width (Integer) —

    the proposed new natural width for context

Returns:

  • (nil)

#reset ⇒ nil

Resets any previously cached request and allocation
data.

When underlying GtkTreeModel 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().

Returns:

  • (nil)