CYIFocusEngine Class Reference

Detailed Description

An interface for a focus engine. Focus engines manage focus navigation within You.i Engine.

A focus engine instance is created as part of the app's initialization.

#include <focus/YiFocusEngine.h>

Inheritance diagram for CYIFocusEngine:

Public Types
enum	FocusabilityStatus {   FocusabilityStatus::CanBeFocused = 0x00,   FocusabilityStatus::ViewNull = 0x01,   FocusabilityStatus::ViewNotFocusable = 0x02,   FocusabilityStatus::ViewInvisible = 0x04,   FocusabilityStatus::ViewNotStaged = 0x08,   FocusabilityStatus::FocusEngineSpecific = 0x10 }

Public Member Functions
	CYIFocusEngine ()
virtual	~CYIFocusEngine ()=default
virtual bool	Init (CYISceneNode *pLogicalRoot)=0
virtual void	Update ()=0
virtual void	ClearFocus ()=0
virtual void	HandleKeyInputs (const CYIKeyEvent *pKeyEvent)=0
virtual void	HandleTrackpadInputs (const CYITrackpadEvent *pKeyEvent)=0
virtual void	CancelTrackpadSwipes ()=0
virtual const CYISceneView *	GetViewWithFocus () const =0
CYISceneView *	GetViewWithFocus ()
const CYISceneView *	GetViewWithFocus (const CYISceneNode *pRootNode) const
CYISceneView *	GetViewWithFocus (const CYISceneNode *pRootNode)
virtual const CYISceneView *	FindNextFocus (const CYISceneView *pSearchFrom, CYIFocus::Direction direction, const CYIFocusSearchOptions &options=CYIFocusSearchOptions())=0
virtual bool	RequestFocus (const CYISceneView *pViewToFocus, CYIFocus::FocusRootRule focusRootRule=CYIFocus::FocusRootRule::DescendantsUpdateContext)=0
virtual bool	MoveFocus (CYIFocus::Direction direction, const CYIFocusSearchOptions &options=CYIFocusSearchOptions())=0
bool	CanBeFocused (const CYISceneView *pView) const
virtual FocusabilityStatus	GetViewFocusability (const CYISceneView *pViewToFocus) const =0

Public Attributes
CYISignal< CYISceneView * >	ViewWithFocusChanged

Member Enumeration Documentation

FocusabilityStatus

enum CYIFocusEngine::FocusabilityStatus

strong

An enum that lists the possible focusability states for a view.

Enumerator
CanBeFocused	The view can be focused.
ViewNull	The view can't be focused because it's null.
ViewNotFocusable	The view can't be focused because it's not marked as focusable. See also CYISceneView::SetFocusable
ViewInvisible	The view can't be focused because it's invisible. See also CYISceneNode::Show
ViewNotStaged	The view can't be focused because it's not part of the scene tree. See also CYISceneManager::StageScene
FocusEngineSpecific	The view can't be focused due to an unspecified focus engine-specific reason.

Constructor & Destructor Documentation

CYIFocusEngine()

CYIFocusEngine::CYIFocusEngine

(

)

~CYIFocusEngine()

virtual CYIFocusEngine::~CYIFocusEngine ( )

virtualdefault

Member Function Documentation

CanBeFocused()

bool CYIFocusEngine::CanBeFocused

(

const CYISceneView *

pView

)

const

Returns true if the given view can receive focus.

In order to receive focus a view must be reachable, have its visibility set to true, and be set to focusable.

See also

CYISceneView::IsFocusable

CYISceneNode::IsTrulyVisible

CYISceneManager::IsReachable

CancelTrackpadSwipes()

virtual void CYIFocusEngine::CancelTrackpadSwipes ( )

pure virtual

Cancels any in-progress trackpad swipes.

Implemented in CYIYouiFocusEngine, and CYINullFocusEngine.

ClearFocus()

virtual void CYIFocusEngine::ClearFocus ( )

pure virtual

Clears the currently focused view, if any.

Implemented in CYIYouiFocusEngine, and CYINullFocusEngine.

FindNextFocus()

virtual const CYISceneView* CYIFocusEngine::FindNextFocus ( const CYISceneView *  pSearchFrom, CYIFocus::Direction  direction, const CYIFocusSearchOptions &  options = CYIFocusSearchOptions()  )

pure virtual

Finds the next view that can take focus in direction direction, searching from pSearchFrom. If pSearchFrom is nullptr, a search from 'nothing' is performed. Returns nullptr if no new focus target could be found.

Implemented in CYIYouiFocusEngine, and CYINullFocusEngine.

GetViewFocusability()

virtual FocusabilityStatus CYIFocusEngine::GetViewFocusability ( const CYISceneView *  pViewToFocus ) const

pure virtual

Returns details about whether a view can be focused.

Implemented in CYIYouiFocusEngine, and CYINullFocusEngine.

GetViewWithFocus() [1/4]

virtual const CYISceneView* CYIFocusEngine::GetViewWithFocus ( ) const

pure virtual

Returns the view that currently has focus, or null if no view has focus.

Implemented in CYIYouiFocusEngine, and CYINullFocusEngine.

GetViewWithFocus() [2/4]

CYISceneView* CYIFocusEngine::GetViewWithFocus

(

)

Returns the view that currently has focus, or null if no view has focus.

GetViewWithFocus() [3/4]

const CYISceneView* CYIFocusEngine::GetViewWithFocus

(

const CYISceneNode *

pRootNode

)

const

Returns the view that currently has focus, or null if no view has focus. Returns null if the view with focus is not a descendant of pRootNode and is not pRootNode itself.

GetViewWithFocus() [4/4]

CYISceneView* CYIFocusEngine::GetViewWithFocus

(

const CYISceneNode *

pRootNode

)

Returns the view that currently has focus, or null if no view has focus. Returns null if the view with focus is not a descendant of pRootNode and is not pRootNode itself.

HandleKeyInputs()

virtual void CYIFocusEngine::HandleKeyInputs ( const CYIKeyEvent *  pKeyEvent )

pure virtual

Handles focus changes given a CYIEvent::Type::KeyDown event.

Implemented in CYIYouiFocusEngine, and CYINullFocusEngine.

HandleTrackpadInputs()

virtual void CYIFocusEngine::HandleTrackpadInputs ( const CYITrackpadEvent *  pKeyEvent )

pure virtual

Handles focus changes given a trackpad event. This generates focus moves requests (as necessary) as the trackpad events are received.

Implemented in CYIYouiFocusEngine, and CYINullFocusEngine.

Init()

virtual bool CYIFocusEngine::Init ( CYISceneNode *  pLogicalRoot )

pure virtual

Initializes this focus engine. Returns false if initialization failed.

Implemented in CYIYouiFocusEngine, and CYINullFocusEngine.

MoveFocus()

virtual bool CYIFocusEngine::MoveFocus ( CYIFocus::Direction  direction, const CYIFocusSearchOptions &  options = CYIFocusSearchOptions()  )

pure virtual

'Moves' the focus in direction direction, relative to the view that currently has focus. If no view currently has focus, a focus search is started from the current focus root.

options can be used to further restrict the set of valid focus candidates.

Returns true if focus was successfully moved.

Implemented in CYIYouiFocusEngine, and CYINullFocusEngine.

RequestFocus()

virtual bool CYIFocusEngine::RequestFocus ( const CYISceneView *  pViewToFocus, CYIFocus::FocusRootRule  focusRootRule = CYIFocus::FocusRootRule::DescendantsUpdateContext  )

pure virtual

Requests that pViewToFocus receive focus. The view will receive focus if it is focusable. Returns true if pViewToFocus obtained focus or had focus before the request.

For a view to take focus, it must meet the following requirements: it is visible, attached to the tree, and focusable.

focusRootRule dictates whether the focus system will allow the focus request to move to a view outside of the current focus root. When CYIFocus::FocusRootRule::DescendantsUpdateContext is provided this method will return true if pViewToFocus's focus root is updated with pViewToFocus as the current focus in that context.

pViewToFocus must be non-null. If focus needs to be cleared, ClearFocus can be used.

See also

CYISceneView::RequestFocus

Implemented in CYIYouiFocusEngine, and CYINullFocusEngine.

Update()

virtual void CYIFocusEngine::Update ( )

pure virtual

Called by CYISceneManager after the scene tree is updated. This allows the focus engine to update focus after modifications have been made to the scene tree.

Implemented in CYIYouiFocusEngine, and CYINullFocusEngine.

Member Data Documentation

ViewWithFocusChanged

CYISignal<CYISceneView *> CYIFocusEngine::ViewWithFocusChanged

A signal called whenever the view with focus has changed. This signal may be called with null when no view has focus. Unlike CYIEvent::Type::FocusIn and CYIEvent::Type::FocusOut, this function is called synchronously as soon as the focus is moved.

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

• focus/YiFocusEngine.h