Overlay

Remarks

An overlay is a child of the root, not of whatever opened it, and that is forced by painting order: the draw list is document order, so an element can only be drawn over something by coming after it. A popup that lived inside the button that opened it would be painted inside that button's stacking position and clipped by every overflow: hidden between the two. Being a root child costs a reference back to the anchor and buys an overlay that is always on top and never clipped.

⚠ Placement runs a layout pass of its own. Where a popup goes depends on how big it is, and how big it is depends on a layout that has not happened when it opens. So Open updates the document, reads the sizes, and then positions — one extra pass, on a user action, rather than a popup that is in the wrong place for the first frame anybody sees it.

Position is OffsetX, not layout. Moving a popup does not disturb anything: no sibling reflows, no ancestor grows, and dragging one costs a walk rather than a cascade.

Fields and properties (11)

• protected override bool AcceptsFocus

  Whether the focus can rest on this kind of control at all.

• public bool IsOpen

  Whether it is showing.

• public Placement Placement
• public float Gap
• public bool LightDismiss
• public bool CloseOnEscape
• public UiElement? Anchor

  What it is attached to, if anything.

• public static readonly UiPropertyKey PlacementProperty

  Identity for Placement.

• public static readonly UiPropertyKey GapProperty

  Identity for Gap.

• public static readonly UiPropertyKey LightDismissProperty

  Identity for LightDismiss.

• public static readonly UiPropertyKey CloseOnEscapeProperty

  Identity for CloseOnEscape.

Events (1)

• public Action<Overlay, bool>? OpenChanged

  Raised when it opens or closes.

Methods (14)

• protected override void OnCreated()

  Builds whatever this element is made of, once, as it joins a document.

• protected override void OnRemoved()
• public void Open(UiElement? target = null)

  Shows it, beside an anchor.

• public void Show(bool open, UiElement? target = null)

  Makes it whichever of the two the caller says, from wherever it is now.

• public void Close(CloseReason reason = Code)

  Hides it.

• public void Reposition()

  Puts it where its placement asks, flipping if there is no room.

• public void MoveTo(float x, float y)

  Puts its top-left corner at a point in document space.

• protected virtual void OnOpened()

  Called after it opens.

• protected virtual void OnClosed(CloseReason reason)

  Called after it closes.

• protected virtual bool IsOutside(UiElement? hit)

  Whether a press at a point should close it.

• public void ClearPlacement()

  Unsets Placement, so it takes its default or its ancestor's value again.

• public void ClearGap()

  Unsets Gap, so it takes its default or its ancestor's value again.

• public void ClearLightDismiss()

  Unsets LightDismiss, so it takes its default or its ancestor's value again.

• public void ClearCloseOnEscape()

  Unsets CloseOnEscape, so it takes its default or its ancestor's value again.

Used by (59, showing 40)

• GalleryHelloUi
• AccessibilityNotificationTestsVixen.Ui.Controls.Tests
• BoundOverlaySheetVixen.Ui.Controls.Tests
• ColorInputVixen.Ui.Controls.Advanced
• ComboBoxVixen.Ui.Controls
• ComboEditorVixen.Ui.Controls
• CommandBindingTestsVixen.Ui.Controls.Tests
• ContextMenuVixen.Ui.Controls
• ContextMenuMarkupTestsVixen.Ui.Controls.Tests
• ControlVisualTestsVixen.Ui.Controls.Tests
• DialogVixen.Ui.Controls
• DialogServiceVixen.Ui.Controls
• DialogSessionVixen.Ui.Controls
• DialogTestsVixen.Ui.Controls.Tests
• DocumentClosePromptTestsVixen.Ui.Controls.Tests
• DrawerVixen.Ui.Controls
• ElementStateBitTestsVixen.Ui.Controls.Tests
• MenuVixen.Ui.Controls
• MenuBarVixen.Ui.Controls
• MenuBarItemVixen.Ui.Controls
• MenuItemVixen.Ui.Controls
• NestedTagTestsVixen.Ui.Controls.Advanced.Tests
• OverlayInteractionTestsVixen.Ui.Controls.Tests
• OverlayLifetimeTestsVixen.Ui.Controls.Tests
• OverlayMarkupTestsVixen.Ui.Controls.Tests
• PopoverVixen.Ui.Controls
• RadialMenuVixen.Ui.Controls
• SelectBaseVixen.Ui.Controls
• SelectionTestsVixen.Ui.Controls.Tests
• StateDialogTestsVixen.Ui.Controls.Tests
• SurfaceTestsVixen.Ui.Controls.Tests
• TooltipVixen.Ui.Controls
• AddComponentMenuVixen.Editor.App
• AddComponentMenuDumpTestsVixen.Editor.App.Tests
• AddComponentMenuTestsVixen.Editor.App.Tests
• BehaviorAuthoringTestsVixen.Editor.App.Tests
• BrowserSavedFilterTestsVixen.Editor.App.Tests
• CommandPaletteVixen.Editor.Ui
• ComponentTestsVixen.Editor.App.Tests
• ComponentsViewVixen.Editor.App