#include <UiDynamicScrollBoxComponent.h>

Inherits AZ::Component, UiDynamicScrollBoxBus::Handler, UiScrollBoxNotificationBus::Handler, UiInitializationBus::Handler, UiTransformChangeNotificationBus::Handler, and UiElementNotificationBus::Handler.

Classes
struct	CachedElementInfo

struct	DisplayedElement

struct	ElementIndexInfo

struct	Section

Public Member Functions
	AZ_COMPONENT (UiDynamicScrollBoxComponent, LyShine::UiDynamicScrollBoxComponentUuid, AZ::Component)

void	RefreshContent () override

void	AddElementsToEnd (int numElementsToAdd, bool scrollToEndIfWasAtEnd) override

void	RemoveElementsFromFront (int numElementsToRemove) override

void	ScrollToEnd () override

int	GetElementIndexOfChild (AZ::EntityId childElement) override

int	GetSectionIndexOfChild (AZ::EntityId childElement) override

AZ::EntityId	GetChildAtElementIndex (int index) override

AZ::EntityId	GetChildAtSectionAndElementIndex (int sectionIndex, int index) override

bool	GetAutoRefreshOnPostActivate () override

void	SetAutoRefreshOnPostActivate (bool autoRefresh) override

AZ::EntityId	GetPrototypeElement () override

void	SetPrototypeElement (AZ::EntityId prototypeElement) override

bool	GetElementsVaryInSize () override

void	SetElementsVaryInSize (bool varyInSize) override

bool	GetAutoCalculateVariableElementSize () override

void	SetAutoCalculateVariableElementSize (bool autoCalculateSize) override

float	GetEstimatedVariableElementSize () override

void	SetEstimatedVariableElementSize (float estimatedSize) override

bool	GetSectionsEnabled () override

void	SetSectionsEnabled (bool enabled) override

AZ::EntityId	GetPrototypeHeader () override

void	SetPrototypeHeader (AZ::EntityId prototypeHeader) override

bool	GetHeadersSticky () override

void	SetHeadersSticky (bool stickyHeaders) override

bool	GetHeadersVaryInSize () override

void	SetHeadersVaryInSize (bool varyInSize) override

bool	GetAutoCalculateVariableHeaderSize () override

void	SetAutoCalculateVariableHeaderSize (bool autoCalculateSize) override

float	GetEstimatedVariableHeaderSize () override

void	SetEstimatedVariableHeaderSize (float estimatedSize) override

void	OnScrollOffsetChanging (AZ::Vector2 newScrollOffset) override

void	OnScrollOffsetChanged (AZ::Vector2 newScrollOffset) override

void	InGamePostActivate () override

void	OnCanvasSpaceRectChanged (AZ::EntityId entityId, const UiTransformInterface::Rect &oldRect, const UiTransformInterface::Rect &newRect) override

void	OnUiElementBeingDestroyed () override

Static Public Member Functions
static void	GetProvidedServices (AZ::ComponentDescriptor::DependencyArrayType &provided)

static void	GetIncompatibleServices (AZ::ComponentDescriptor::DependencyArrayType &incompatible)

static void	GetRequiredServices (AZ::ComponentDescriptor::DependencyArrayType &required)

static void	Reflect (AZ::ReflectContext *context)

Protected Types
enum	ElementType { SectionHeader , Item , NumElementTypes }

Protected Member Functions
void	Activate () override

void	Deactivate () override

	AZ_DISABLE_COPY_MOVE (UiDynamicScrollBoxComponent)

void	PrepareListForDisplay ()

AZ::Entity *	GetContentEntity () const

AZ::EntityId	ClonePrototypeElement (ElementType elementType, AZ::EntityId parentEntityId=AZ::EntityId()) const

bool	IsPrototypeElement (AZ::EntityId entityId) const

bool	AllPrototypeElementsValid () const

bool	AnyPrototypeElementsNavigable () const

bool	AnyElementTypesHaveVariableSize () const

bool	AnyElementTypesHaveEstimatedSizes () const

bool	AllElementTypesHaveEstimatedSizes () const

bool	StickyHeadersEnabled () const

void	ResizeContentToFitElements ()

void	ResizeContentElement (float newSize) const

void	AdjustContentSizeAndScrollOffsetByDelta (float sizeDelta, float scrollDelta) const

float	CalculateVariableElementSize (int index)

float	GetAndCacheVariableElementSize (int index)

float	GetVariableElementSize (int index) const

int	GetLastKnownAccumulatedSizeIndex (int index, int numElementsWithUnknownSizeOut[ElementType::NumElementTypes]) const

float	GetElementOffsetAtIndex (int index) const

float	GetFixedSizeElementOffset (int index) const

float	GetVariableSizeElementOffset (int index) const

void	UpdateAverageElementSize (int numAddedElements, float sizeDelta)

void	ClearDisplayedElements ()

AZ::EntityId	FindDisplayedElementWithIndex (int index) const

float	GetVisibleAreaSize () const

bool	AreAnyElementsVisible (AZ::Vector2 &visibleContentBoundsOut) const

void	UpdateElementVisibility (bool keepAtEndIfWasAtEnd=false)

void	CalculateVisibleElementIndices (bool keepAtEndIfWasAtEnd, const AZ::Vector2 &visibleContentBounds, int &firstVisibleElementIndexOut, int &lastVisibleElementIndexOut, int &firstDisplayedElementIndexOut, int &lastDisplayedElementIndexOut, int &firstDisplayedElementIndexWithSizeChangeOut, float &totalElementSizeChangeOut, float &scrollChangeOut)

void	UpdateStickyHeader (int firstVisibleElementIndex, int lastVisibleElementIndex, float visibleContentBeginning)

int	FindFirstVisibleHeaderIndex (int firstVisibleElementIndex, int lastVisibleElementIndex, int excludeIndex)

void	FindVisibleElementIndicesForFixedSizes (const AZ::Vector2 &visibleContentBounds, int &firstVisibleElementIndexOut, int &lastVisibleElementIndexOut) const

int	FindVisibleElementIndexToRemainInPlace (const AZ::Vector2 &visibleContentBounds) const

void	AddExtraElementsForNavigation (int &firstDisplayedElementIndexOut, int &lastDisplayedElementIndexOut) const

int	EstimateFirstVisibleElementIndex (const AZ::Vector2 &visibleContentBounds) const

int	FindFirstVisibleElementIndex (int estimatedIndex, const AZ::Vector2 &visibleContentBounds, float &firstVisibleElementEndOut) const

void	CalculateVisibleSpaceBeforeAndAfterElement (int visibleElementIndex, bool keepAtEnd, float visibleAreaBeginning, float &spaceLeftBeforeOut, float &spaceLeftAfterOut) const

void	CalculateVisibleElementIndicesFromVisibleElementIndex (int visibleElementIndex, const AZ::Vector2 &visibleContentBound, bool keepAtEnd, int &firstVisibleElementIndexOut, int &lastVisibleElementIndexOut, int &firstDisplayedElementIndexOut, int &lastDisplayedElementIndexOut, int &firstDisplayedElementIndexWithSizeChangeOut, float &totalElementSizeChangeOut, float &scrollChangeOut)

float	CalculateContentBeginningDeltaAfterSizeChange (float contentSizeDelta) const

float	CalculateContentEndDeltaAfterSizeChange (float contentSizeDelta) const

bool	IsScrolledToEnd () const

bool	IsElementDisplayedAtIndex (int index) const

AZ::EntityId	GetElementForDisplay (ElementType elementType)

AZ::EntityId	GetElementForAutoSizeCalculation (ElementType elementType)

void	DisableElementsForAutoSizeCalculation () const

float	AutoCalculateElementSize (AZ::EntityId elementForAutoSizeCalculation) const

void	SizeVariableElementAtIndex (AZ::EntityId element, int index) const

void	PositionElementAtIndex (AZ::EntityId element, int index) const

void	SetElementAnchors (AZ::EntityId element) const

void	SetElementOffsets (AZ::EntityId element, float offset) const

ElementType	GetElementTypeAtIndex (int index) const

ElementIndexInfo	GetElementIndexInfoFromIndex (int index) const

int	GetIndexFromElementIndexInfo (const ElementIndexInfo &elementIndexInfo) const

AZ::EntityId	GetImmediateContentChildFromDescendant (AZ::EntityId childElement) const

bool	HeadersHaveVariableSizes () const

bool	IsValidPrototype (AZ::EntityId entityId) const

Protected Attributes
bool	m_autoRefreshOnPostActivate
	Whether the list should refresh automatically on post activate.

int	m_defaultNumElements
	Number of elements by default. Overridden by UiDynamicListDataBus::GetNumElements.

AZ::EntityId	m_itemPrototypeElement

bool	m_variableItemElementSize

bool	m_autoCalculateItemElementSize

float	m_estimatedItemElementSize

bool	m_hasSections
	Whether the list is divided into sections with headers.

int	m_defaultNumSections
	Number of sections by default. Overridden by UiDynamicListDataBus::GetNumSections.

AZ::EntityId	m_headerPrototypeElement

bool	m_stickyHeaders

bool	m_variableHeaderElementSize

bool	m_autoCalculateHeaderElementSize

float	m_estimatedHeaderElementSize

AZ::EntityId	m_prototypeElement [ElementType::NumElementTypes]
	The entity Ids of the prototype elements.

float	m_prototypeElementSize [ElementType::NumElementTypes]

bool	m_variableElementSize [ElementType::NumElementTypes]

bool	m_autoCalculateElementSize [ElementType::NumElementTypes]

float	m_estimatedElementSize [ElementType::NumElementTypes]

bool	m_isPrototypeElementNavigable [ElementType::NumElementTypes]
	Whether elements in the list are navigable.

float	m_averageElementSize
	Average element size of the elements with known sizes.

int	m_numElementsUsedForAverage
	The number of elements used to calculate the current average.

float	m_lastCalculatedVisibleContentOffset

bool	m_isVertical
	Whether the list is vertical or horizontal. Determined by the scroll box.

AZStd::list< DisplayedElement >	m_displayedElements
	A list of currently displayed elements.

AZStd::list< AZ::EntityId >	m_recycledElements [ElementType::NumElementTypes]
	A list of unused entities.

AZ::EntityId	m_clonedElementForAutoSizeCalculation [ElementType::NumElementTypes]
	Cloned entities used to auto calculate sizes.

DisplayedElement	m_currentStickyHeader
	The header that is currently sticky at the top or left of the visible area.

int	m_firstDisplayedElementIndex
	First and last element indices that are being displayed (Not necessarily visible in viewport since we add an extra element for gamepad/keyboard navigation purposes)

int	m_lastDisplayedElementIndex

int	m_firstVisibleElementIndex
	First and last element indices that are visible in the viewport.

int	m_lastVisibleElementIndex

AZStd::vector< CachedElementInfo >	m_cachedElementInfo
	Cached element sizes. Used when elements can vary in size.

int	m_numElements
	The virtual number of elements in the list. Includes both headers and items.

AZStd::vector< Section >	m_sections
	List of the sections in the list.

bool	m_listPreparedForDisplay
	Whether the list has been set up for display.

Detailed Description

This component dynamically sets up scrollbox content as a horizontal or vertical list of elements that are cloned from prototype entities. Only the minimum number of entities are created for efficient scrolling, and are reused when new elements come into view. The list can consist of only items, or it can be divided into sections that include a header at the beginning of each section, followed by items that belong to that section. The meaning of "element" differs in the public and private interface, mainly for backward compatibility. In the private interface, "element" refers to a generic entry in the list which can be of different types. Currently there are two types of elements: headers and items. In the public interface however, "element" means the same thing as "item" does in the private interface, and "item" is unused (the public interface does not need to define the concept of a generic entry in the list.) Both headers and items can have fixed sizes determined by their corresponding prototype entities, or they could vary in size. If they vary in size, another option is available to indicate whether to auto calculate the sizes or request the sizes via a bus interface. There is also the option to provide an estimated size that will be used until the elements scroll into view and their real size calculated. For lists with a large number of elements, it is advisable to use the estimated size as calculating the sizes of all elements up front could be costly. When elements vary in size, a cache is maintained and the element sizes are only calculated once.

Member Data Documentation

◆ m_autoCalculateElementSize

bool UiDynamicScrollBoxComponent::m_autoCalculateElementSize[ElementType::NumElementTypes]

protected

Whether element sizes should be auto calculated or whether they should be requested. Applies when elements can vary in size

◆ m_autoCalculateHeaderElementSize

bool UiDynamicScrollBoxComponent::m_autoCalculateHeaderElementSize

protected

Whether header sizes should be auto calculated or whether they should be requested. Applies when headers can vary in size

◆ m_autoCalculateItemElementSize

bool UiDynamicScrollBoxComponent::m_autoCalculateItemElementSize

protected

Whether item sizes should be auto calculated or whether they should be requested. Applies when items can vary in size

◆ m_estimatedElementSize

float UiDynamicScrollBoxComponent::m_estimatedElementSize[ElementType::NumElementTypes]

protected

An estimated height or width for the element size. If set to greater than 0, this size will be used until an element goes into view and its real size is calculated. Applies when elements can vary in size

◆ m_estimatedHeaderElementSize

float UiDynamicScrollBoxComponent::m_estimatedHeaderElementSize

protected

An estimated height or width for the header size. If set to greater than 0, this size will be used until a header goes into view and its real size is calculated. Applies when headers can vary in size

◆ m_estimatedItemElementSize

float UiDynamicScrollBoxComponent::m_estimatedItemElementSize

protected

An estimated height or width for the item size. If set to greater than 0, this size will be used until an item goes into view and its real size is calculated. Applies when items can vary in size

◆ m_headerPrototypeElement

AZ::EntityId UiDynamicScrollBoxComponent::m_headerPrototypeElement

protected

The prototype element for the headers in the list. Used when sections are enabled

◆ m_itemPrototypeElement

AZ::EntityId UiDynamicScrollBoxComponent::m_itemPrototypeElement

protected

The prototype element for the items in the list. Used when sections are enabled

◆ m_lastCalculatedVisibleContentOffset

float UiDynamicScrollBoxComponent::m_lastCalculatedVisibleContentOffset

protected

The last calculated offset from the top or left of the content's parent (the visible area) to the top or left of the content. Used to estimate a first visible element index

◆ m_prototypeElementSize

float UiDynamicScrollBoxComponent::m_prototypeElementSize[ElementType::NumElementTypes]

protected

Stores the size of the prototype elements before they are removed from the content element's child list. Used to calculate the content size and element offsets when there is no variation in element size

◆ m_stickyHeaders

bool UiDynamicScrollBoxComponent::m_stickyHeaders

protected

Whether headers should stick to the beginning of the visible area Used when sections are enabled

◆ m_variableElementSize

bool UiDynamicScrollBoxComponent::m_variableElementSize[ElementType::NumElementTypes]

protected

Whether elements in the list can vary in size (height for vertical lists and width for horizontal lists) If false, the element size is fixed and is determined by the prototype element

◆ m_variableHeaderElementSize

bool UiDynamicScrollBoxComponent::m_variableHeaderElementSize

protected

Whether headers in the list can vary in size (height for vertical lists and width for horizontal lists) If false, the header size is fixed and is determined by the prototype element

◆ m_variableItemElementSize

bool UiDynamicScrollBoxComponent::m_variableItemElementSize

protected

Whether items in the list can vary in size (height for vertical lists and width for horizontal lists) If false, the item size is fixed and is determined by the prototype element

The documentation for this class was generated from the following file:

Gems/LyShine/Code/Source/UiDynamicScrollBoxComponent.h

Classes

Public Member Functions

Static Public Member Functions

Protected Types

Protected Member Functions

Protected Attributes

Detailed Description

Member Data Documentation

◆ m_autoCalculateElementSize

◆ m_autoCalculateHeaderElementSize

◆ m_autoCalculateItemElementSize

◆ m_estimatedElementSize

◆ m_estimatedHeaderElementSize

◆ m_estimatedItemElementSize

◆ m_headerPrototypeElement

◆ m_itemPrototypeElement

◆ m_lastCalculatedVisibleContentOffset

◆ m_prototypeElementSize

◆ m_stickyHeaders

◆ m_variableElementSize

◆ m_variableHeaderElementSize

◆ m_variableItemElementSize