UDreamLayoutContainerScrollBox

本页由 DreamGUIReferenceDocs commandlet 从反射生成，正文是头文件注释的原文（英文），所以不翻译——这样它永远和代码一致。概念讲解见核心概念。

Inherits from UDreamLayoutContainerStackBox.

Declared in Public/Core/Components/DreamPanelLayouts.h.

UMG Scroll Box

Properties

Name	Type	Category	In the details panel	From Blueprint	Description
`ScrollSensitivity`	`float`	ScrollBox	yes	`GetScrollSensitivity` / `SetScrollSensitivity`	Local units scrolled per wheel notch.
`ConsumeMouseWheel`	`EDreamScrollBoxConsumeMouseWheel`	ScrollBox	yes	`GetConsumeMouseWheel` / `SetConsumeMouseWheel`	Whether the wheel is swallowed here or handed to an outer scroll box once this one is at a limit.
`WheelScrollMultiplier`	`float`	ScrollBox	yes	`GetWheelScrollMultiplier` / `SetWheelScrollMultiplier`	A plain multiplier on whatever one wheel notch already travels -- UMG's WheelScrollMultiplier. ScrollSensitivity is the distance; this scales it, so "the same feel, twice as fast" is one number and not a re-tuned one.
`NavigationDestination`	`EDreamUIScrollDestination`	ScrollBox	yes	`GetNavigationDestination` / `SetNavigationDestination`	Where a widget revealed by ScrollWidgetIntoView ends up -- UMG's NavigationDestination.
`NavigationScrollPadding`	`float`	ScrollBox	yes	`GetNavigationScrollPadding` / `SetNavigationScrollPadding`	How much of the window to keep clear around a revealed widget, in local units -- UMG's NavigationScrollPadding. Stops a row landing flush against the edge with its neighbour cut in half beside it, which is the only cue a player has that the list continues.
`ScrollWhenFocusChanges`	`EDreamUIScrollWhenFocusChanges`	ScrollBox	yes	`GetScrollWhenFocusChanges` / `SetScrollWhenFocusChanges`	What this box does when user focus lands inside it -- UMG's ScrollWhenFocusChanges. Read by FDreamUINavigationScroll, which is the only thing that reveals a widget because focus moved.
`AnalogMouseWheelKey`	`FKey`	ScrollBox	yes	`GetAnalogMouseWheelKey` / `SetAnalogMouseWheelKey`	The analog key that acts as this box's mouse wheel -- UMG's AnalogMouseWheelKey. Invalid (the default) means "whatever the input preset already routes here", which is the right stick and therefore exactly today's behaviour.
`Scrollbar`	`TWeakObjectPtr<UDreamUIBehaviour>`	ScrollBox	yes	read / write	A scrollbar behaviour to keep in step with this box, both ways -- a UUIScrollbar, or anything else that implements IDreamUIScrollbarInterface. Assign the component from a scrollbar prefab (/DreamGUI/Prefabs/VerticalScrollbar or HorizontalScrollbar) placed anywhere in the hierarchy -- it does not have to be a child of this box. Which end of the bar means zero is the BAR's business: this box always feeds the raw 0..1 fraction and the bar's own DirectionType decides the mapping.
`ScrollbarVisibility`	`EDreamScrollBoxScrollbarVisibility`	ScrollBox	yes	`GetScrollbarVisibility` / `SetScrollbarVisibility`	Whether that bar hides itself when the content already fits.
`bAnimateWheelScrolling`	`bool`	ScrollBox	yes	`GetAnimateWheelScrolling` / `SetAnimateWheelScrolling`	Ease to the wheel's new position over a few frames instead of jumping there.
`ScrollAnimationMode`	`EDreamScrollAnimationMode`	ScrollBox	yes	`GetScrollAnimationMode` / `SetScrollAnimationMode`	Which curve an eased scroll follows.
`ScrollAnimationInterpolationSpeed`	`float`	ScrollBox	yes	`GetScrollAnimationInterpolationSpeed` / `SetScrollAnimationInterpolationSpeed`	FInterpTo speed, used by InterpToSpeed only. Larger arrives sooner; UMG's default is 15.
`ScrollAnimationEase`	`EDreamTweenEase`	ScrollBox	yes	`GetScrollAnimationEase` / `SetScrollAnimationEase`	Curve shape, used by EaseCurve only. Any of DreamTween's easings, overshooting ones included.
`ScrollAnimationDuration`	`float`	ScrollBox	yes	`GetScrollAnimationDuration` / `SetScrollAnimationDuration`	Seconds an eased scroll takes, used by EaseCurve only.
`bEnableInertia`	`bool`	ScrollBox	yes	`GetEnableInertia` / `SetEnableInertia`	Keep moving under momentum after the finger or mouse lets go.
`DecelerationRate`	`float`	ScrollBox	yes	`GetDecelerationRate` / `SetDecelerationRate`	How quickly momentum dies. 0 never slows down; larger values stop sooner. Same units and default as the legacy scroll view, so a value tuned there carries over.
`bAllowOverscroll`	`bool`	ScrollBox	yes	`GetAllowOverscroll` / `SetAllowOverscroll`	Let the content rubber-band past an end while dragging, then spring back on release.
`OverscrollLimit`	`float`	ScrollBox	yes	`GetOverscrollLimit` / `SetOverscrollLimit`	How far past an end the content can be pulled, in local units. The pull saturates towards this rather than stopping at it, so the resistance grows the further out you drag and the content can never be dragged away indefinitely -- which the legacy view's flat damping allowed.
`bBackPadScrolling`	`bool`	ScrollBox	yes	`GetBackPadScrolling` / `SetBackPadScrolling`	A whole viewport of empty space BEFORE the content -- UMG's BackPadScrolling: at offset zero the first child sits one viewport in, so the first item can be scrolled all the way to the far edge. A viewport rather than half of one, which is Slate's arithmetic (SScrollPanel's ScrollPadding is the panel's own length). It adds to the scroll range and takes nothing from what a Fill slot is given.
`bFrontPadScrolling`	`bool`	ScrollBox	yes	`GetFrontPadScrolling` / `SetFrontPadScrolling`	A whole viewport of empty space AFTER the content -- UMG's FrontPadScrolling, so the last item can reach the near edge.
`bAllowRightClickDragScrolling`	`bool`	ScrollBox	yes	`GetAllowRightClickDragScrolling` / `SetAllowRightClickDragScrolling`	Whether a drag with the RIGHT button scrolls this box -- UMG's bAllowRightClickDragScrolling, on by default as there. Off leaves the right button to whatever wants it for a context menu. On, a right drag is still refused while there is nothing to scroll, as SScrollBox refuses it unless its bar IsNeeded. A left-button drag scrolls whatever this says: it is this library's own gesture, and existing screens rely on it.
`bEnableTouchScrolling`	`bool`	ScrollBox	yes	`GetEnableTouchScrolling` / `SetEnableTouchScrolling`	Whether a finger dragging over the box scrolls it -- UMG's bEnableTouchScrolling, on by default as there.
`ScrollOffset`	`float`	ScrollBox	yes	-	Distance scrolled from the start. Editable so the designer can scroll the content in the prefab editor (where no pointer input exists) to reach and edit off-screen children; the authored value is also the initial scroll position at runtime. Clamped to [0, GetMaxScrollOffset()] by layout.

Functions

Function	Kind	Description
`bool CanScrollWidgetIntoView(UDreamWidget* InWidget)`	callable	True when InWidget lives in this box and a scroll would bring more of it into sight. The question directional navigation has to answer before it commits to a candidate it cannot currently see.
`void EndInertialScrolling()`	callable	Drop the fling, keeping the position and whatever rubber band is open -- UMG's name for it.
`bool GetAllowOverscroll()`	pure	Get Allow Overscroll
`bool GetAllowRightClickDragScrolling()`	pure	Get Allow Right Click Drag Scrolling
`FKey GetAnalogMouseWheelKey()`	pure	Get Analog Mouse Wheel Key
`float GetAnimatedScrollTarget()`	pure	Where an eased scroll is heading; the current offset when nothing is animating.
`bool GetAnimateWheelScrolling()`	pure	Get Animate Wheel Scrolling
`bool GetBackPadScrolling()`	pure	Get Back Pad Scrolling
`EDreamScrollBoxConsumeMouseWheel GetConsumeMouseWheel()`	pure	Get Consume Mouse Wheel
`float GetDecelerationRate()`	pure	Get Deceleration Rate
`bool GetEnableInertia()`	pure	Get Enable Inertia
`bool GetEnableTouchScrolling()`	pure	Get Enable Touch Scrolling
`bool GetFrontPadScrolling()`	pure	Get Front Pad Scrolling
`float GetMaxScrollOffset()`	pure	How far this box can scroll: content extent minus viewport extent, or 0 when everything fits.
`EDreamUIScrollDestination GetNavigationDestination()`	pure	Get Navigation Destination
`float GetNavigationScrollPadding()`	pure	Get Navigation Scroll Padding
`float GetOverscroll()`	pure	Signed displacement past an end, damped; zero while in range. Layout adds it to the offset.
`float GetOverscrollLimit()`	pure	Get Overscroll Limit
`float GetOverscrollPercentage()`	pure	The same displacement as a PERCENTAGE of the window -- UMG's GetOverscrollPercentage.
`float GetScrollAnimationDuration()`	pure	Get Scroll Animation Duration
`EDreamTweenEase GetScrollAnimationEase()`	pure	Get Scroll Animation Ease
`float GetScrollAnimationInterpolationSpeed()`	pure	Get Scroll Animation Interpolation Speed
`EDreamScrollAnimationMode GetScrollAnimationMode()`	pure	Get Scroll Animation Mode
`UDreamUIBehaviour* GetScrollbar()`	pure	The bar this box drives. Takes the raw pointer, because the stored form is a weak one.
`EDreamScrollBoxScrollbarVisibility GetScrollbarVisibility()`	pure	Get Scrollbar Visibility
`float GetScrollOffset()`	pure	Distance scrolled from the start, in local units. Always within [0, GetMaxScrollOffset()].
`float GetScrollOffsetOfEnd()`	pure	The offset at which the end of the content is in view -- UMG's name for GetMaxScrollOffset.
`float GetScrollSensitivity()`	pure	The plain readers and writers for every knob above.
`float GetScrollVelocity()`	pure	Get Scroll Velocity
`EDreamUIScrollWhenFocusChanges GetScrollWhenFocusChanges()`	pure	Get Scroll when Focus Changes
`float GetViewFraction()`	pure	Fraction of the content currently visible, 0..1. 1 when everything fits.
`float GetViewOffsetFraction()`	pure	How far through the scrollable range the view sits, 0..1. 0 when nothing can scroll.
`float GetWheelScrollMultiplier()`	pure	Get Wheel Scroll Multiplier
`bool IsAnimatingScroll()`	pure	True while an eased scroll is still running.
`bool IsScrollGestureMirrored()`	pure	True when a GESTURE on this box has to be read backwards -- a horizontal box in a right-to-left layout, and nothing else.
`bool IsScrolling()`	pure	True while momentum or a spring-back is still moving the content.
`bool IsScrollNeeded()`	pure	Whether there is anything to scroll: content longer than the viewport, as the last layout pass measured it -- SScrollBar's IsNeeded. False before the first pass, which has measured nothing yet.
`bool ScrollBy(float Delta)`	callable	Scroll by a signed delta. Returns true when the offset actually changed, false when already at a limit.
`void ScrollToEnd()`	callable	Jump to the end of the content.
`void ScrollToStart()`	callable	Jump to the start of the content.
`bool ScrollWidgetIntoView(UDreamWidget* InWidget, bool bAnimateScroll, EDreamUIScrollDestination InDestination, float InPadding)`	callable	Scroll the minimum distance that brings InWidget into view. Accepts any descendant, not just a direct child. Returns false when the widget is not inside this box or nothing needed to move. Eased by default, as UMG's is -- a jump loses the reader's place on a long list.
`void SetAllowOverscroll(bool Value)`	callable	Set Allow Overscroll
`void SetAllowRightClickDragScrolling(bool Value)`	callable	Read when a drag begins, so a gesture already under way keeps the answer it started with.
`void SetAnalogMouseWheelKey(FKey Value)`	callable	Set Analog Mouse Wheel Key
`void SetAnimateWheelScrolling(bool Value)`	callable	Set Animate Wheel Scrolling
`void SetBackPadScrolling(bool Value)`	callable	Moves where offset zero puts the content and lengthens the range, so the box is re-arranged.
`void SetConsumeMouseWheel(EDreamScrollBoxConsumeMouseWheel Value)`	callable	Set Consume Mouse Wheel
`void SetDecelerationRate(float Value)`	callable	Set Deceleration Rate
`void SetEnableInertia(bool Value)`	callable	Set Enable Inertia
`void SetEnableTouchScrolling(bool Value)`	callable	Set Enable Touch Scrolling
`void SetFrontPadScrolling(bool Value)`	callable	Set Front Pad Scrolling
`void SetNavigationDestination(EDreamUIScrollDestination Value)`	callable	Set Navigation Destination
`void SetNavigationScrollPadding(float Value)`	callable	Set Navigation Scroll Padding
`void SetOverscrollLimit(float Value)`	callable	Set Overscroll Limit
`void SetScrollAnimationDuration(float Value)`	callable	Set Scroll Animation Duration
`void SetScrollAnimationEase(EDreamTweenEase Value)`	callable	Set Scroll Animation Ease
`void SetScrollAnimationInterpolationSpeed(float Value)`	callable	Set Scroll Animation Interpolation Speed
`void SetScrollAnimationMode(EDreamScrollAnimationMode Value)`	callable	Set Scroll Animation Mode
`void SetScrollbar(UDreamUIBehaviour* Value)`	callable	Link a scrollbar behaviour; one that does not implement IDreamUIScrollbarInterface is refused.
`void SetScrollbarVisibility(EDreamScrollBoxScrollbarVisibility Value)`	callable	Set Scrollbar Visibility
`void SetScrollOffset(float Value)`	callable	Set Scroll Offset
`void SetScrollOffsetAnimated(float Value)`	callable	Ease towards Value over the coming frames instead of moving now. Cancels any momentum.
`void SetScrollSensitivity(float Value)`	callable	Set Scroll Sensitivity
`void SetScrollVelocity(float Value)`	callable	Set Scroll Velocity
`void SetScrollWhenFocusChanges(EDreamUIScrollWhenFocusChanges Value)`	callable	Set Scroll when Focus Changes
`void SetWheelScrollMultiplier(float Value)`	callable	Set Wheel Scroll Multiplier
`void StopScrolling()`	callable	Drop momentum and any rubber-band displacement immediately.
`void TickScrollPhysics(float DeltaTime)`	callable	Advance momentum and spring-back by DeltaTime. Deliberately free of input plumbing: the physics can then be stepped directly by a test, which is the only way any of this gets verified without a real pointer.

Events

Event	Signature	Description
`OnUserScrolled`	`void DreamScrollBoxUserScrolledEvent__DelegateSignature(float CurrentOffset)`

UDreamLayoutContainerScrollBox

Properties

Functions

Events

本页目录