RadioButton

touchgfx/widgets/RadioButton.hpp

Radio button with two states. A RadioButton is a button that changes appearance (state) when it has been pushed. Pushing the RadioButton again will return the to original state.

To make managing radio buttons much easier, they can be added to a RadioButtonGroup which then automates deselecting radio buttons when a new radio button is pressed.

See: RadioButtonGroup

Inherits from: AbstractButton, Widget, Drawable

Public Functions

virtual void	draw(const Rect & invalidatedArea) const
	Draw this drawable.
void	executeDeselectedAction()
	Executes the previously set action.
uint8_t	getAlpha() const
	Gets the current alpha value, as previously set using setAlpha.
Bitmap	getCurrentlyDisplayedBitmap() const
	Gets currently displayed bitmap.
bool	getDeselectionEnabled() const
	Gets the current deselectionEnabled state.
bool	getSelected() const
	Gets the current selected state.
virtual Rect	getSolidRect() const
	Get (the largest possible) rectangle that is guaranteed to be solid (opaque).
virtual void	handleClickEvent(const ClickEvent & event)
	Updates the current state of the button.
virtual void	invalidateContent() const
	Tell the framework that the contents of the Drawable needs to be redrawn.
	RadioButton()
void	setAlpha(uint8_t newAlpha)
	Sets the alpha channel for the RadioButton, i.e.
virtual void	setBitmaps(const Bitmap & bmpUnselected, const Bitmap & bmpUnselectedPressed, const Bitmap & bmpSelected, const Bitmap & bmpSelectedPressed)
	Sets the four bitmaps used by this button.
void	setDeselectedAction(GenericCallback< const AbstractButton & > & callback)
	Associates an action to be performed when the RadioButton is deselected.
void	setDeselectionEnabled(bool state)
	Sets whether or not it is possible to deselect the RadioButton by clicking it.
void	setSelected(bool newSelected)
	Sets the radio buttons selected state.

Protected Attributes

uint8_t	alpha
	The current alpha value. 255=solid, 0=invisible.
Bitmap	bitmapSelected
	The image to display when radio button selected and released.
Bitmap	bitmapSelectedPressed
	The image to display when radio button selected and pressed.
Bitmap	bitmapUnselected
	The image to display when radio button unselected and released.
Bitmap	bitmapUnselectedPressed
	The image to display when radio button unselected and pressed.
GenericCallback< const AbstractButton & > *	deselectedAction
	The callback to be executed when this AbstractButton is deselected.
bool	deselectionEnabled
	Is it possible to deselect by pressing a selected RadioButton.
bool	selected
	The current selected state.

Additional inherited members

Public Functions inherited from AbstractButton

	AbstractButton()
	Sets this Widget touchable so the user can interact with buttons.
virtual void	executeAction()
	Executes the previously set action.
virtual bool	getPressedState() const
	Function to determine if the AbstractButton is currently pressed.
void	setAction(GenericCallback< const AbstractButton & > & callback)
	Associates an action with the button.

Protected Attributes inherited from AbstractButton

GenericCallback< const AbstractButton & > *	action
	The callback to be executed when this AbstractButton is clicked.
bool	pressed
	Is the button pressed or released? True if pressed.

Public Functions inherited from Widget

virtual void	getLastChild(int16_t , int16_t , Drawable ** last)
	Since a Widget is only one Drawable, Widget::getLastChild simply yields itself as result, but only if the Widget isVisible and isTouchable.

Public Functions inherited from Drawable

void	center()
	Centers the Drawable inside its parent.
void	centerX()
	Center the Drawable horizontally inside its parent.
void	centerY()
	Center the Drawable vertically inside its parent.
virtual void	childGeometryChanged()
	This function can be called on parent nodes to signal that the size or position of one or more of its children has changed.
	Drawable()
	Initializes a new instance of the Drawable class.
void	drawToDynamicBitmap(BitmapId id)
	Render the Drawable object into a dynamic bitmap.
void	expand(int margin =0)
	Expands the Drawable to have the same size as its parent with a given margin around the edge.
Rect	getAbsoluteRect() const
	Helper function for obtaining the rectangle this Drawable covers, expressed in absolute coordinates.
virtual Drawable *	getFirstChild()
	Function for obtaining the first child of this drawable if any.
int16_t	getHeight() const
	Gets the height of this Drawable.
virtual void	getLastChild(int16_t x, int16_t y, Drawable ** last) =0
	Function for obtaining the the last child of this drawable that intersects with the specified point.
Drawable *	getNextSibling()
	Gets the next sibling node.
Drawable *	getParent() const
	Returns the parent node.
const Rect &	getRect() const
	Gets the rectangle this Drawable covers, in coordinates relative to its parent.
virtual Rect	getSolidRectAbsolute()
	Helper function for obtaining the largest solid rect (as implemented by getSolidRect()) expressed in absolute coordinates.
virtual void	getVisibleRect(Rect & rect) const
	Function for finding the visible part of this drawable.
int16_t	getWidth() const
	Gets the width of this Drawable.
int16_t	getX() const
	Gets the x coordinate of this Drawable, relative to its parent.
int16_t	getY() const
	Gets the y coordinate of this Drawable, relative to its parent.
virtual void	handleDragEvent(const DragEvent & event)
	Defines the event handler interface for DragEvents.
virtual void	handleGestureEvent(const GestureEvent & event)
	Defines the event handler interface for GestureEvents.
virtual void	handleTickEvent()
	Called periodically by the framework if the Drawable instance has subscribed to timer ticks.
virtual void	invalidate() const
	Tell the framework that this entire Drawable needs to be redrawn.
virtual void	invalidateRect(Rect & invalidatedArea) const
	Request that a region of this drawable is redrawn.
bool	isTouchable() const
	Gets whether this Drawable receives touch events or not.
bool	isVisible() const
	Gets whether this Drawable is visible.
virtual void	moveRelative(int16_t x, int16_t y)
	Moves the drawable.
virtual void	moveTo(int16_t x, int16_t y)
	Moves the drawable.
virtual void	setHeight(int16_t height)
	Sets the height of this drawable.
void	setPosition(const Drawable & drawable)
	Sets the position of the Drawable to the same as the given Drawable.
void	setPosition(int16_t x, int16_t y, int16_t width, int16_t height)
	Sets the size and position of this Drawable, relative to its parent.
void	setTouchable(bool touch)
	Controls whether this Drawable receives touch events or not.
void	setVisible(bool vis)
	Controls whether this Drawable should be visible.
virtual void	setWidth(int16_t width)
	Sets the width of this drawable.
void	setWidthHeight(const Bitmap & bitmap)
	Sets the dimensions (width and height) of the Drawable without changing the x and y coordinates).
void	setWidthHeight(const Drawable & drawable)
	Sets the dimensions (width and height) of the Drawable without changing the x and y coordinates).
void	setWidthHeight(const Rect & other)
	Sets the dimensions (width and height) of the Drawable without changing the x and y coordinates).
void	setWidthHeight(int16_t width, int16_t height)
	Sets the dimensions (width and height) of the Drawable without changing the x and y coordinates).
virtual void	setX(int16_t x)
	Sets the x coordinate of this Drawable, relative to its parent.
void	setXY(const Drawable & drawable)
	Sets the x and y coordinates of this Drawable.
void	setXY(int16_t x, int16_t y)
	Sets the x and y coordinates of this Drawable, relative to its parent.
virtual void	setY(int16_t y)
	Sets the y coordinate of this Drawable, relative to its parent.
virtual void	translateRectToAbsolute(Rect & r) const
	Helper function for converting a region of this Drawable to absolute coordinates.
virtual	~Drawable()
	Finalizes an instance of the Drawable class.

Protected Attributes inherited from Drawable

Drawable *	nextSibling
	Pointer to the next Drawable.
Drawable *	parent
	Pointer to this drawable's parent.
Rect	rect
	The coordinates of this Drawable, relative to its parent.
bool	touchable
	True if this drawable should receive touch events.
bool	visible
	True if this drawable should be drawn.

Public Functions Documentation

draw

virtual void draw	(	const Rect &	invalidatedArea	)

Draw this drawable.

It is a requirement that the draw implementation does not draw outside the region specified by invalidatedArea.

Parameters:

invalidatedArea	The sub-region of this drawable that needs to be redrawn, expressed in coordinates relative to its parent (e.g. for a complete redraw, invalidatedArea will be (0, 0, width, height).

Reimplements: touchgfx::Drawable::draw

executeDeselectedAction

void executeDeselectedAction	(			)

Executes the previously set action.

See also:

setDeselectedAction

getAlpha

uint8_t getAlpha	(			)	const

Gets the current alpha value, as previously set using setAlpha.

The default alpha value (if the alpha value has not been changed using setAlpha) is 255=solid.

Returns:

The current alpha value ranging from 255=solid to 0=invisible.

See also:

setAlpha

getCurrentlyDisplayedBitmap

Bitmap getCurrentlyDisplayedBitmap	(			)	const

Gets currently displayed bitmap.

This depends on whether the RadioButton is currently selected or not and whether it is being pressed or not, i.e. it depends on the radio button's pressed and selected state.

Returns:

The bitmap currently displayed.

getDeselectionEnabled

bool getDeselectionEnabled	(			)	const

Gets the current deselectionEnabled state.

Returns:

The current deselectionEnabled state.

See also:

setDeselectionEnabled

getSelected

bool getSelected	(			)	const

Gets the current selected state.

Returns:

The current selected state.

getSolidRect

virtual Rect getSolidRect	(			)	const

Get (the largest possible) rectangle that is guaranteed to be solid (opaque).

This information is important, as any Drawable underneath the solid area does not need to be drawn.

Returns:

The solid rectangle part of the Drawable.

Note

The rectangle returned must be relative to upper left corner of the Drawable, meaning that a completely solid widget should return the full size Rect(0, 0, getWidth(), getHeight()). If no area can be guaranteed to be solid, an empty Rect must be returned. Failing to return the correct rectangle may result in errors on the display.

Reimplements: touchgfx::Drawable::getSolidRect

handleClickEvent

virtual void handleClickEvent	(	const ClickEvent &	event	)

Updates the current state of the button.

The state can be either pressed or released, and if the new state is different from the current state, the button is also invalidated to force a redraw.

If the button state is changed from ClickEvent::PRESSED to ClickEvent::RELEASED, the associated action (if any) is also executed.

Parameters:

event	Information about the click.

Reimplements: touchgfx::AbstractButton::handleClickEvent

invalidateContent

virtual void invalidateContent	(			)	const

Tell the framework that the contents of the Drawable needs to be redrawn.

If the Drawable is invisible, nothing happens. Subclasses of Drawable are encouraged to implement this function and invalidate as little as possible, i.e. the smallest rectangle covering the visual element(s) drawn by the widget.

Reimplements: touchgfx::Drawable::invalidateContent

RadioButton

RadioButton	(			)

setAlpha

void setAlpha	(	uint8_t	newAlpha	)

Sets the alpha channel for the RadioButton, i.e.

all the images used. The default alpha value on a RadioButton is 255.

Parameters:

newAlpha	The alpha value ranging from 255=solid to 0=invisible.

See also:

getAlpha

setBitmaps

virtual void setBitmaps	(	const Bitmap &	bmpUnselected ,
		const Bitmap &	bmpUnselectedPressed ,
		const Bitmap &	bmpSelected ,
		const Bitmap &	bmpSelectedPressed
		)

Sets the four bitmaps used by this button.

The first two bitmaps must show the unselected Button when it is released and pressed. The last two bitmaps must show the selected Button when it is released and pressed.

Parameters:

bmpUnselected	Bitmap to use when button is unselected and released.
bmpUnselectedPressed	Bitmap to use when button is unselected and pressed.
bmpSelected	Bitmap to use when button is selected and released.
bmpSelectedPressed	Bitmap to use when button is selected and pressed.

Note

It is not uncommon to have the same bitmap for released (normal) and pressed state.

setDeselectedAction

void setDeselectedAction	(	GenericCallback< const AbstractButton & > &	callback	)

Associates an action to be performed when the RadioButton is deselected.

Parameters:

callback	The callback to be executed. The callback will be given a reference to the AbstractButton.

Note

The action performed when the RadioButton is selected, is set using setAction().

setDeselectionEnabled

void setDeselectionEnabled	(	bool	state	)

Sets whether or not it is possible to deselect the RadioButton by clicking it.

By default it is not possible to deselect a RadioButton. The meaning of this is most clear when the RadioButton is used in a RadioButtonGroup where exactly one RadioButton should always be selected. Pressing the currently selected RadioButton should not deselect it, but rather select it again. This makes the button "sticky", i.e. a button can only be deselected by selecting another RadioButton in the same RadioButtonGroup.

Parameters:

state	true if it should be possible to deselect by click. Default is false.

See also:

getDeselectionEnabled

setSelected

void setSelected	(	bool	newSelected	)

Sets the radio buttons selected state.

Note that the associated action is also performed.

Parameters:

newSelected	The new selected state.

Note

If the RadioButton is part of a RadioButtonGroup, setting the selected state of individual RadioButtons is not recommended.

See also:

setAction, setDeselectedAction, RadioButtonGroup

Protected Attributes Documentation

alpha

uint8_t alpha

The current alpha value. 255=solid, 0=invisible.

bitmapSelected

Bitmap bitmapSelected

The image to display when radio button selected and released.

bitmapSelectedPressed

Bitmap bitmapSelectedPressed

The image to display when radio button selected and pressed.

bitmapUnselected

Bitmap bitmapUnselected

The image to display when radio button unselected and released.

bitmapUnselectedPressed

Bitmap bitmapUnselectedPressed

The image to display when radio button unselected and pressed.

deselectedAction

GenericCallback< const AbstractButton & > * deselectedAction

The callback to be executed when this AbstractButton is deselected.

deselectionEnabled

bool deselectionEnabled

Is it possible to deselect by pressing a selected RadioButton.

selected

bool selected

The current selected state.