PopupLayout

Object Hierarchy:

Description:

[ CCode ( ref_function = "gdk_popup_layout_ref" , type_id = "gdk_popup_layout_get_type ()" , unref_function = "gdk_popup_layout_unref" ) ]
[ Compact ]
public class PopupLayout

Popups are positioned relative to their parent surface.

The GdkPopupLayout struct contains information that is necessary to do so.

The positioning requires a negotiation with the windowing system, since it depends on external constraints, such as the position of the parent surface, and the screen dimensions.

The basic ingredients are a rectangle on the parent surface, and the anchor on both that rectangle and the popup. The anchors specify a side or corner to place next to each other.

![Popup anchors](popup-anchors.png)

For cases where placing the anchors next to each other would make the popup extend offscreen, the layout includes some hints for how to resolve this problem. The hints may suggest to flip the anchor position to the other side, or to 'slide' the popup along a side, or to resize it.

![Flipping popups](popup-flip.png)

![Sliding popups](popup-slide.png)

These hints may be combined.

Ultimatively, it is up to the windowing system to determine the position and size of the popup. You can learn about the result by calling get_position_x, get_position_y, get_rect_anchor and get_surface_anchor after the popup has been presented. This can be used to adjust the rendering. For example, GtkPopover changes its arrow position accordingly. But you have to be careful avoid changing the size of the popover, or it has to be presented again.

Namespace: Gdk

Package: gtk4

Content:

Creation methods:

public PopupLayout (Rectangle anchor_rect, Gravity rect_anchor, Gravity surface_anchor)
Create a popup layout description.

Methods:

public unowned PopupLayout @ref ()
Increases the reference count of value.
public PopupLayout copy ()
Create a new PopupLayout and copy the contents of this into it.
public bool equal (PopupLayout other)
Check whether this and other has identical layout properties.
public AnchorHints get_anchor_hints ()
Get the AnchorHints.
public unowned Rectangle? get_anchor_rect ()
Get the anchor rectangle.
public void get_offset (out int dx, out int dy)
Retrieves the offset for the anchor rectangle.
public Gravity get_rect_anchor ()
Returns the anchor position on the anchor rectangle.
public void get_shadow_width (out int left, out int right, out int top, out int bottom)
Obtains the shadow widths of this layout.
public Gravity get_surface_anchor ()
Returns the anchor position on the popup surface.
public void set_anchor_hints (AnchorHints anchor_hints)
Set new anchor hints.
public void set_anchor_rect (Rectangle anchor_rect)
Set the anchor rectangle.
public void set_offset (int dx, int dy)
Offset the position of the anchor rectangle with the given delta.
public void set_rect_anchor (Gravity anchor)
Set the anchor on the anchor rectangle.
public void set_shadow_width (int left, int right, int top, int bottom)
The shadow width corresponds to the part of the computed surface size that would consist of the shadow margin surrounding the window, would there be any.
public void set_surface_anchor (Gravity anchor)
Set the anchor on the popup surface.
public void unref ()
Decreases the reference count of value.