class: CellAreaContext

[21:7] extends: object

Stores geometrical information for a series of rows in a GtkCellArea The GtkCellAreaContext object is created by a given GtkCellArea implementation via its GtkCellAreaClass.create_context() virtual method and is used to store cell sizes and alignments for a series of GtkTreeModel rows that are requested and rendered in the same context. GtkCellLayout widgets can create any number of contexts in which to request and render groups of data rows. However, it’s important that the same context which was used to request sizes for a given GtkTreeModel row also be used for the same row when calling other GtkCellArea APIs such as gtk_cell_area_render() and gtk_cell_area_event().

Members

• handleObj
• lib
• retainedCallbacks
• signalHandlerNames
• signalSetterHandlers

Methods

• CellAreaContext (Handle = null)

  Creates a new CellAreaContext by wrapping a native handle or another wrapper.

  • @p Handle is the native handle or another wrapper whose handle to adopt.

• toNativeHandle (Source)

  Normalizes a constructor argument into a raw pointer carrier. Accepts a raw NativeHandle, a raw NativeBuffer returned from fn.call(...), another generated wrapper exposing handle(), or null. Returns null when the argument carries no pointer.

  • @p Source is the raw handle, raw buffer, wrapper, or null.
  • @r A raw pointer carrier or null when no pointer is present.

• getLib ()

  Returns the opened native library for this generated wrapper.

  • @r The opened native library.

• handle ()

  Returns the wrapped NativeHandle.

  • @r The wrapped NativeHandle.

• isNull ()

  Returns true when the wrapped handle is null.

  • @r A bool.

• describe ()

  Returns a small string for debugging generated wrappers.

  • @r A string.

• asObject ()

  Wraps this handle as Object.

  • @r A Object object.

• allocate (int width, int height)

  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.

  • @p width is the allocated width for all GtkTreeModel rows rendered with
  • @context, or -1.
  • @p height is the allocated height for all GtkTreeModel rows rendered with @context, or -1.
  • @r None.

• get_area ()

  Fetches the GtkCellArea this @context was created by. This is generally unneeded by layouting widgets; however, it is important for the context implementation itself to fetch information about the area it is being used for. For instance at GtkCellAreaContextClass.allocate() time it’s important to know details about any cell spacing that the GtkCellArea is configured with in order to compute a proper allocation.

• push_preferred_height (int minimum_height, int natural_height)

  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.

  • @p minimum_height is the proposed new minimum height for @context.
  • @p natural_height is the proposed new natural height for @context.
  • @r None.

• push_preferred_width (int minimum_width, int natural_width)

  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.

  • @p minimum_width is the proposed new minimum width for @context.
  • @p natural_width is the proposed new natural width for @context.
  • @r None.

• reset ()

  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().

  • @r None.

class: CellAreaContextMeta

[198:14] static extends: object

Generated metadata helpers for CellAreaContext class surfaces.

Methods

• properties ()

  Returns property metadata for CellAreaContext.

  • @r A list.