Screen

A Screen represents a full-screen drawable area. Applications create specific screens by subclassing this class. Each Screen has a root container to which drawables are added. The Screen makes sure to delegate draw requests and various events to the appropriate drawables in correct order.

Inherited by: View< T >

Public Functions

virtual void	afterTransition()
	Called by Application::handleTickEvent() when the transition to the screen is done.
void	bindTransition(Transition & trans)
	Enables the transition to access the containers.
void	draw()
	Tells the screen to draw its entire area.
virtual void	draw(Rect & rect)
	Tell the screen to draw the specified area.
Container &	getRootContainer()
	Obtain a reference to the root container of this screen.
int16_t	getScreenHeight() const
	Gets height of the current screen.
int16_t	getScreenWidth() const
	Gets width of the current screen.
virtual void	handleClickEvent(const ClickEvent & event)
	Traverse the drawables in reverse z-order and notify them of a click event.
virtual void	handleDragEvent(const DragEvent & event)
	Traverse the drawables in reverse z-order and notify them of a drag event.
virtual void	handleGestureEvent(const GestureEvent & event)
	Handle gestures.
virtual void	handleKeyEvent(uint8_t key)
	Called by the Application on the reception of a "key", the meaning of which is platform/application specific.
virtual void	handleTickEvent()
	Called by the Application on the current screen with a frequency of Application::TICK_INTERVAL_MS.
void	JSMOC(const Rect & invalidatedArea, Drawable * widgetToDraw)
	Recursive JSMOC function.
	Screen()
	Initializes a new instance of the Screen class.
virtual void	setupScreen()
	Called by Application::switchScreen() when this screen is going to be displayed.
void	startSMOC(const Rect & invalidatedArea)
	Starts a JSMOC run, analyzing what parts of what widgets should be redrawn.
virtual void	tearDownScreen()
	Called by Application::switchScreen() when this screen will no longer be displayed.
bool	usingSMOC() const
	Determines if using JSMOC.
virtual	~Screen()
	Finalizes an instance of the Screen class.

Protected Functions

void	add(Drawable & d)
	Add a drawable to the content container.
void	insert(Drawable * previous, Drawable & d)
	Inserts a Drawable after a specific child node.
void	invalidate() const
	Tell the framework that this entire Screen needs to be redrawn.
void	invalidateRect(Rect & invalidatedArea) const
	Request that a region of this root container on the screen is redrawn.
void	remove(Drawable & d)
	Removes a drawable from the content container.
void	useSMOCDrawing(bool enabled)
	Determines whether to use JSMOC or painter's algorithm for drawing.

Protected Attributes

Container	container
	The container contains the contents of the screen.
Drawable *	focus
	The drawable currently in focus (set when DOWN_PRESSED is received).

Public Functions Documentation

afterTransition

virtual void afterTransition	(			)

Called by Application::handleTickEvent() when the transition to the screen is done.

Base version does nothing, but override to do screen specific initialization code that has to be done after the transition to the screen.

See also:

Application::handleTickEvent

bindTransition

void bindTransition	(	Transition &	trans	)

Enables the transition to access the containers.

Parameters:

trans	The transition to bind.

draw

void draw	(			)

Tells the screen to draw its entire area.

Note

The more specific draw(Rect&) version is preferred when possible.

draw

virtual void draw	(	Rect &	rect	)

Tell the screen to draw the specified area.

Will traverse the drawables tree from in z-order and delegate draw to them.

Parameters:

rect	The area in absolute coordinates.

Note

The given rect must be in absolute coordinates.

getRootContainer

Container & getRootContainer	(			)

Obtain a reference to the root container of this screen.

Returns:

The root container.

getScreenHeight

int16_t getScreenHeight	(			)	const

Gets height of the current screen.

In most cases, this is the same as HAL::DISPLAY_HEIGHT.

Returns:

The screen height.

getScreenWidth

int16_t getScreenWidth	(			)	const

Gets width of the current screen.

In most cases, this is the same as HAL::DISPLAY_WIDTH.

Returns:

The screen width.

handleClickEvent

virtual void handleClickEvent	(	const ClickEvent &	event	)

Traverse the drawables in reverse z-order and notify them of a click event.

Parameters:

event	The event to handle.

handleDragEvent

virtual void handleDragEvent	(	const DragEvent &	event	)

Traverse the drawables in reverse z-order and notify them of a drag event.

Parameters:

event	The event to handle.

handleGestureEvent

virtual void handleGestureEvent	(	const GestureEvent &	event	)

Handle gestures.

Traverses drawables in reverse-z and notifies them of the gesture.

Parameters:

event	The event to handle.

handleKeyEvent

virtual void handleKeyEvent	(	uint8_t	key	)

Called by the Application on the reception of a "key", the meaning of which is platform/application specific.

Default implementation does nothing.

Parameters:

key	The key to handle.

handleTickEvent

virtual void handleTickEvent	(			)

Called by the Application on the current screen with a frequency of Application::TICK_INTERVAL_MS.

JSMOC

void JSMOC	(	const Rect &	invalidatedArea ,
		Drawable *	widgetToDraw
		)

Recursive JSMOC function.

This is the actual occlusion culling implementation.

Parameters:

invalidatedArea	The area to redraw, expressed in absolute coordinates.
widgetToDraw	Widget currently being drawn.

Note

JSMOC is an abbreviation of Jesper, Sren & Martin's Occlusion Culling.

Screen

Screen	(			)

Initializes a new instance of the Screen class.

setupScreen

virtual void setupScreen	(			)

Called by Application::switchScreen() when this screen is going to be displayed.

Base version does nothing, but place any screen specific initialization code in an overridden version.

See also:

Application::switchScreen

startSMOC

void startSMOC	(	const Rect &	invalidatedArea	)

Starts a JSMOC run, analyzing what parts of what widgets should be redrawn.

Parameters:

invalidatedArea	The area to redraw, expressed in absolute coordinates.

Note

SMOC is an abbreviation of Sren & Martin's Occlusion Culling.

tearDownScreen

virtual void tearDownScreen	(			)

Called by Application::switchScreen() when this screen will no longer be displayed.

Base version does nothing, but place any screen specific cleanup code in an overridden version.

See also:

Application::switchScreen

usingSMOC

bool usingSMOC	(			)	const

Determines if using JSMOC.

Returns:

true if this screen uses the JSMOC drawing algorithm.

~Screen

virtual ~Screen	(			)

Finalizes an instance of the Screen class.

Protected Functions Documentation

add

void add	(	Drawable &	d	)

Add a drawable to the content container.

Parameters:

d	The Drawable to add.

Note

Must not be called with a Drawable that was already added to the screen. If in doubt, call remove() first.

insert

void insert	(	Drawable *	previous ,
		Drawable &	d
		)

Inserts a Drawable after a specific child node.

See Container::insert.

Parameters:

previous	The Drawable to insert after. If null, insert as header.
d	The Drawable to insert.

Note

As with add, do not add the same drawable twice.

See also:

Container::insert

invalidate

void invalidate	(			)	const

Tell the framework that this entire Screen needs to be redrawn.

See also:

Container::invalidate

invalidateRect

void invalidateRect	(	Rect &	invalidatedArea	)

Request that a region of this root container on the screen is redrawn.

See Container::invalidateRect.

To invalidate the entire Screen, use invalidate()

Parameters:

invalidatedArea	The area of this drawable to redraw expressed in coordinates relative to the root container.

Note

The invalidatedArea position is relative to the root container, which is usually the same as the Screen coordinates.

See also:

Container::invalidateRect

remove

void remove	(	Drawable &	d	)

Removes a drawable from the content container.

Safe to call even if the drawable was never added (in which case nothing happens).

Parameters:

d	The Drawable to remove.

useSMOCDrawing

void useSMOCDrawing	(	bool	enabled	)

Determines whether to use JSMOC or painter's algorithm for drawing.

Parameters:

enabled	true if JSMOC should be enabled, false if disabled (meaning painter's algorithm is employed instead).

Protected Attributes Documentation

container

Container container

The container contains the contents of the screen.

focus

Drawable * focus

The drawable currently in focus (set when DOWN_PRESSED is received).