ScrollView

Remarks

Scrolling is an offset, not a layout. ScrollTop writes OffsetY on the content, which is applied when absolute positions are accumulated — so a scroll costs one walk of the tree and no cascade, no flexbox and no measurement. A scroll view that moved its content by changing a layout property would relayout its entire subtree sixty times a second.

⚠ Everything stays in the tree, including what has scrolled out of sight. This is the plain scroll view; a list of a million rows wants VirtualizingPanel, which doc 09 makes a first-class primitive and which is owed. Said here rather than discovered: putting a hundred thousand elements in one of these will work and will not be fast.

The clipping is overflow: hidden in the theme rather than anything here, so it is the draw list's clip stack that does it — the same mechanism any other clipped element uses.

Fields and properties (12)

• protected override string TagName

  The element name this type answers to when a caller does not choose one.

• protected override bool AcceptsFocus

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

• public UiElement Content

  Where the content goes.

• protected override UiElement ContentHost
• public ScrollBar VerticalBar

  The bar down the right.

• public ScrollBar HorizontalBar

  The bar along the bottom.

• public float ScrollTop
• public float ScrollLeft
• public float MaximumTop

  How far down it can go.

• public float MaximumLeft

  How far across it can go.

• public static readonly UiPropertyKey ScrollTopProperty

  Identity for ScrollTop.

• public static readonly UiPropertyKey ScrollLeftProperty

  Identity for ScrollLeft.

Events (1)

• public Action<ScrollView>? Scrolled

  Raised when either offset changes.

Methods (6)

• protected override void OnCreated()

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

• protected override void OnRemoved()

  Called once, as the element leaves the document.

• public void ScrollIntoView(UiElement element)

  Scrolls until an element inside is visible.

• public void Refresh()

  Brings the bars up to date with the content's size.

• public void ClearScrollTop()

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

• public void ClearScrollLeft()

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

Used by (28)

• ShellHelloUi
• CodeEditorVixen.Ui.Controls.Advanced
• CodeEditorTestsVixen.Ui.Controls.Advanced.Tests
• ControlVisualTestsVixen.Ui.Controls.Tests
• DataGridVixen.Ui.Controls.Advanced
• DataGridTestsVixen.Ui.Controls.Advanced.Tests
• NavigationInteractionTestsVixen.Ui.Controls.Tests
• SurfaceTestsVixen.Ui.Controls.Tests
• TextFieldTestsVixen.Ui.Controls.Tests
• TreeViewVixen.Ui.Controls.Advanced
• TreeViewTestsVixen.Ui.Controls.Advanced.Tests
• VirtualizingGridVixen.Ui.Controls
• VirtualizingGridTestsVixen.Ui.Controls.Tests
• VirtualizingPanelVixen.Ui.Controls
• VirtualizingPanelTestsVixen.Ui.Controls.Tests
• AddComponentMenuVixen.Editor.App
• AddComponentMenuTestsVixen.Editor.App.Tests
• AssetGridVixen.Editor.App
• ConsoleViewVixen.Editor.Ui
• ConsoleViewTestsVixen.Editor.Ui.Tests
• EditorApplicationVixen.Editor.App
• ImportSettingsViewVixen.Editor.AssetEditors
• InspectorPanelTestsVixen.Editor.App.Tests
• InspectorViewVixen.Editor.Inspector
• MemoryViewVixen.Editor.Profiler
• MessageLogViewVixen.Editor.Ui
• ProfilerViewVixen.Editor.Profiler
• UndoHistoryVixen.Editor.App