ScrollBase

touchgfx/containers/scrollers/ScrollBase.hpp

The ScrollBase class is an abstract class used for Widgets that needs to show (a lot of) elements in a DrawableList that can be scrolled. Due to memory limitations, this is implemented by re-using the Drawables in the DrawableList - once an element is moved off screen, it is filled with new content and moved to the other end and the of the scrolling list.

Lists can be horizontal or vertical and the can be circular (infinite scrolling).

See:

• ScrollList, ScrollWheel, ScrollWheelWithSelectionStyle
• ScrollWheelBase, DrawableList

Inherits from: Container, Drawable

Inherited by: ScrollList, ScrollWheelBase

Protected Types

enum	AnimationState { NO_ANIMATION, ANIMATING_GESTURE, ANIMATING_DRAG }
	Values that represent animation states.

Public Functions

void	allowHorizontalDrag(bool enable)
	Enables horizontal scrolling to be passed to the children in the list (in case a child widget is able to handle drag events).
void	allowVerticalDrag(bool enable)
	Enables the vertical scroll.
virtual void	animateToItem(int16_t itemIndex, int16_t animationSteps =-1)
	Go to a specific item, possibly with animation.
uint16_t	getAnimationSteps() const
	Gets animation steps as set in setAnimationSteps.
virtual bool	getCircular() const
	Gets the circular setting, previously set using setCircular().
uint16_t	getDragAcceleration() const
	Gets drag acceleration (times 10).
virtual int16_t	getDrawableMargin() const
	Gets drawable margin as set through the second parameter in most recent call to setDrawableSize().
virtual int16_t	getDrawableSize() const
	Gets drawable size as set through the first parameter in most recent call to setDrawableSize().
virtual bool	getHorizontal() const
	Gets the orientation of the drawables, previously set using setHorizontal().
bool	getIsPressed() const
	Gets if the container is currently pressed.
bool	getIsScrolling() const
	Gets if the containner is currently scrolled.
uint16_t	getMaxSwipeItems() const
	Gets maximum swipe items as set by setMaxSwipeItems.
virtual int16_t	getNumberOfItems() const
	Gets number of items in the DrawableList, as previously set using setNumberOfItems().
uint8_t	getOvershootPercentage() const
	Gets overshoot percentage, as previously set using setOvershootPercentage.
uint16_t	getSwipeAcceleration() const
	Gets swipe acceleration (times 10).
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	initialize()
	Removed all drawables and initializes the content of these items.
bool	isAnimating() const
	Query if an animation is ongoing.
virtual void	itemChanged(int itemIndex)
	Inform the scroll list that the contents of an item has changed and force all drawables with the given item index to be updated via the callback provided.
	ScrollBase()
void	setAnimationEndedCallback(GenericCallback<> & callback)
	Callback, called when the set animation ended.
void	setAnimationSteps(int16_t steps)
	Sets animation steps (in ticks) when moving to a new selected item.
virtual void	setCircular(bool circular)
	Sets whether the list is circular (infinite) or not.
void	setDragAcceleration(uint16_t acceleration)
	Sets drag acceleration times 10, so "10" means "1", "15" means "1.5".
virtual void	setDrawableSize(int16_t drawableSize, int16_t drawableMargin)
	Sets drawables size.
void	setEasingEquation(EasingEquation equation)
	Sets easing equation when changing the selected item, for example via swipe or AnimateTo.
virtual void	setHeight(int16_t height)
	Sets the height of this drawable.
virtual void	setHorizontal(bool horizontal)
	Sets a horizontal or vertical layout.
void	setItemPressedCallback(GenericCallback< int16_t > & callback)
	Set Callback which will be called when a item is pressed.
void	setItemSelectedCallback(GenericCallback< int16_t > & callback)
	Sets Callback which will be called when the selected item is clicked or dragged.
void	setMaxSwipeItems(uint16_t maxItems)
	Sets maximum swipe items.
virtual void	setNumberOfItems(int16_t numberOfItems)
	Sets number of items in the DrawableList.
void	setOvershootPercentage(uint8_t percentage)
	Sets overshoot percentage when dragging a non-circular list.
void	setSwipeAcceleration(uint16_t acceleration)
	Sets swipe acceleration (times 10).
virtual void	setWidth(int16_t width)
	Sets the width of this drawable.
void	stopAnimation()
	Stops an animation if one is ongoing.

Protected Functions

virtual void	animateToPosition(int32_t position, int16_t steps =-1)
	Animate to a new position/offset using the given number of steps.
virtual int32_t	getNearestAlignedOffset(int32_t offset) const
	Gets nearest offset aligned to a multiple of itemSize.
int	getNormalizedOffset(int offset) const
	Gets normalized offset from a given offset from 0 down to -numItems*itemSize.
virtual int32_t	getOffset() const
	Gets display offset of first item.
virtual int32_t	getPositionForItem(int16_t itemIndex) =0
	Get the position for an item.
virtual int32_t	keepOffsetInsideLimits(int32_t newOffset, int16_t overShoot) const =0
	Keep offset inside limits.
virtual void	setOffset(int32_t offset)
	Sets display offset of first item.

Protected Attributes

GenericCallback *	animationEndedCallback
	The animation ended callback.
AnimationState	currentAnimationState
	The current animation state.
uint16_t	defaultAnimationSteps
	The animation steps.
int16_t	distanceBeforeAlignedItem
	The distance before aligned item.
uint16_t	dragAcceleration
	The drag acceleration x10.
bool	draggableX
	Is the container draggable in the horizontal direction.
bool	draggableY
	Is the container draggable in the vertical direction.
EasingEquation	easingEquation
	The easing equation used for animation.
int	gestureEnd
	The gesture end.
int	gestureStart
	The gesture start.
int	gestureStep
	The current gesture step.
int	gestureStepsTotal
	The total gesture steps.
int32_t	initialSwipeOffset
	The initial swipe offset.
bool	isPressed
	Is the container currently pressed (maybe show scrollbars)
bool	isScrolling
	Is the container scrolling (i.e. has overcome the initial larger drag that is required to initiate a scroll).
GenericCallback *	itemLockedInCallback
	The item locked in callback.
GenericCallback< int16_t > *	itemPressedCallback
	The item pressed callback.
GenericCallback< int16_t > *	itemSelectedCallback
	The item selected callback.
int16_t	itemSize
	Size of the item (including margin)
DrawableList	list
	The list.
uint16_t	maxSwipeItems
	The maximum swipe items.
int16_t	numberOfDrawables
	Number of drawables.
uint8_t	overshootPercentage
	The overshoot percentage when dragging.
uint16_t	swipeAcceleration
	The swipe acceleration x10.
int16_t	xClick
	The x coordinate of a click.
int16_t	yClick
	The y coordinate of a click.

Additional inherited members

Public Functions inherited from Container

virtual void	add(Drawable & d)
	Adds a Drawable instance as child to this Container.
	Container()
virtual bool	contains(const Drawable & d)
	Query if a given Drawable has been added directly to this Container.
virtual void	draw(const Rect & invalidatedArea) const
	Draw this drawable.
virtual void	forEachChild(GenericCallback< Drawable & > * function)
	Executes the specified callback function for each child in the Container.
virtual Drawable *	getFirstChild()
	Obtain a pointer to the first child of this container.
virtual void	getLastChild(int16_t x, int16_t y, Drawable ** last)
	Gets the last child in the list of children in this Container.
virtual void	getLastChildNear(int16_t x, int16_t y, Drawable * last, int16_t fingerAdjustmentX, int16_t * fingerAdjustmentY)
	Works similar to getLastChild() but also considers the current set finger size in HAL.
virtual Rect	getSolidRect() const
	Get (the largest possible) rectangle that is guaranteed to be solid (opaque).
virtual void	insert(Drawable * previous, Drawable & d)
	Inserts a Drawable after a specific child node.
virtual void	remove(Drawable & d)
	Removes a Drawable from the container by removing it from the linked list of children.
virtual void	removeAll()
	Removes all children in the Container by resetting their parent and sibling pointers.
virtual void	unlink()
	Removes all children by unlinking the first child.

Protected Functions inherited from Container

virtual Rect	getContainedArea() const
	Gets a rectangle describing the total area covered by the children of this container.
virtual void	moveChildrenRelative(int16_t deltaX, int16_t deltaY)
	Calls moveRelative on all children.

Protected Attributes inherited from Container

Drawable *	firstChild
	Pointer to the first child of this container. Subsequent children can be found through firstChild's nextSibling.

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.
virtual void	draw(const Rect & invalidatedArea) const =0
	Draw this drawable.
	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	getSolidRect() const =0
	Get (the largest possible) rectangle that is guaranteed to be solid (opaque).
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	handleClickEvent(const ClickEvent & event)
	Defines the event handler interface for ClickEvents.
virtual void	invalidate() const
	Tell the framework that this entire Drawable needs to be redrawn.
virtual void	invalidateContent() const
	Tell the framework that the contents of the 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.
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.
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.

Protected Types Documentation

AnimationState

enum AnimationState

Values that represent animation states.

NO_ANIMATION	No animation.
ANIMATING_GESTURE	Animating a gesture.
ANIMATING_DRAG	Animating a drag.

Public Functions Documentation

allowHorizontalDrag

void allowHorizontalDrag	(	bool	enable	)

Enables horizontal scrolling to be passed to the children in the list (in case a child widget is able to handle drag events).

By default, scrolling in either direction is disabled. This function can be used to explicitly (dis)allow scrolling in the horizontal direction.

Parameters:

enable	If true, horizontal scrolling is enabled. If false (default), scrolling is disabled.

allowVerticalDrag

void allowVerticalDrag	(	bool	enable	)

Enables the vertical scroll.

Enables the vertical scroll to be passed to the children in the list (in case a child widget is able to handle drag events). By default, scrolling in either direction is disabled. This function can be used to explicitly (dis)allow scrolling in the vertical direction.

Parameters:

enable	If true, vertical scrolling is enabled. If false (default), scrolling is disabled.

animateToItem

virtual void animateToItem	(	int16_t	itemIndex ,
		int16_t	animationSteps =-1
		)

Go to a specific item, possibly with animation.

The given item index is scrolled into view. If animationSteps is omitted, the default number of animation steps is used. If animationSteps is 0 no animation will be used, otherwise the number of animation steps specified is used.

Parameters:

itemIndex	Zero-based index of the item.
animationSteps	(Optional) The steps to use for the animation. 0 means no animation. If omitted, default animation steps are used.

See also:

setAnimationSteps

getAnimationSteps

uint16_t getAnimationSteps	(			)	const

Gets animation steps as set in setAnimationSteps.

Returns:

The animation steps.

See also:

setAnimationSteps, setEasingEquation

getCircular

virtual bool getCircular	(			)	const

Gets the circular setting, previously set using setCircular().

Returns:

True if the list is circular (infinite), false if the list is not circular (finite).

See also:

DrawableList::getCircular, setCircular

getDragAcceleration

uint16_t getDragAcceleration	(			)	const

Gets drag acceleration (times 10).

Returns:

The drag acceleration.

Note

The reason for multiplying the acceleration by 10 is to avoid introducing floating point arithmetic.

See also:

setDragAcceleration

getDrawableMargin

virtual int16_t getDrawableMargin	(			)	const

Gets drawable margin as set through the second parameter in most recent call to setDrawableSize().

Returns:

The drawable margin.

See also:

setDrawableSize

getDrawableSize

virtual int16_t getDrawableSize	(			)	const

Gets drawable size as set through the first parameter in most recent call to setDrawableSize().

Returns:

The drawable size.

See also:

setDrawableSize

getHorizontal

virtual bool getHorizontal	(			)	const

Gets the orientation of the drawables, previously set using setHorizontal().

Returns:

True if it horizontal, false if it is vertical.

See also:

DrawableList::getHorizontal, setHorizontal

getIsPressed

bool getIsPressed	(			)	const

Gets if the container is currently pressed.

Returns:

if the container is currently pressed.

getIsScrolling

bool getIsScrolling	(			)	const

Gets if the containner is currently scrolled.

Returns:

if the containner is currently scrolled.

getMaxSwipeItems

uint16_t getMaxSwipeItems	(			)	const

Gets maximum swipe items as set by setMaxSwipeItems.

Returns:

The maximum swipe items, 0 means "no limit".

See also:

setMaxSwipeItems

getNumberOfItems

virtual int16_t getNumberOfItems	(			)	const

Gets number of items in the DrawableList, as previously set using setNumberOfItems().

Returns:

The number of items.

See also:

setNumberOfItems, DrawableList::getNumberOfItems

getOvershootPercentage

uint8_t getOvershootPercentage	(			)	const

Gets overshoot percentage, as previously set using setOvershootPercentage.

Returns:

The overshoot percentage.

See also:

setOvershootPercentage

getSwipeAcceleration

uint16_t getSwipeAcceleration	(			)	const

Gets swipe acceleration (times 10).

Returns:

The swipe acceleration.

Note

The reason for multiplying the acceleration by 10 is to avoid introducing floating point arithmetic.

See also:

setSwipeAcceleration

handleDragEvent

virtual void handleDragEvent	(	const DragEvent &	event	)

Defines the event handler interface for DragEvents.

The default implementation ignores the event. The event is only received if the drawable is touchable and visible.

Parameters:

event	The DragEvent received from the HAL.

Reimplements: touchgfx::Drawable::handleDragEvent

Reimplemented by: touchgfx::ScrollWheelBase::handleDragEvent

handleGestureEvent

virtual void handleGestureEvent	(	const GestureEvent &	event	)

Defines the event handler interface for GestureEvents.

The default implementation ignores the event. The event is only received if the Drawable is touchable and visible.

Parameters:

event	The GestureEvent received from the HAL.

Reimplements: touchgfx::Drawable::handleGestureEvent

Reimplemented by: touchgfx::ScrollWheelBase::handleGestureEvent

handleTickEvent

virtual void handleTickEvent	(			)

Called periodically by the framework if the Drawable instance has subscribed to timer ticks.

See also:

Application::registerTimerWidget

Reimplements: touchgfx::Drawable::handleTickEvent

initialize

virtual void initialize	(			)

Removed all drawables and initializes the content of these items.

Reimplemented by: touchgfx::ScrollWheelWithSelectionStyle::initialize

isAnimating

bool isAnimating	(			)	const

Query if an animation is ongoing.

This can be good to know if getSelectedItem() is called, as the result might not be as expected if isAnimating() returns true, since the display is not showing the selected item in the right place yet.

Returns:

true if animating, false if not.

itemChanged

virtual void itemChanged	(	int	itemIndex	)

Inform the scroll list that the contents of an item has changed and force all drawables with the given item index to be updated via the callback provided.

This is important as a circular list with very few items might display the same item more than once and all these items should be updated.

Parameters:

itemIndex	Zero-based index of the changed item.

Reimplemented by: touchgfx::ScrollWheelWithSelectionStyle::itemChanged

ScrollBase

ScrollBase	(			)

setAnimationEndedCallback

void setAnimationEndedCallback	(	GenericCallback<> &	callback	)

Callback, called when the set animation ended.

Parameters:

callback	The ended callback.

setAnimationSteps

void setAnimationSteps	(	int16_t	steps	)

Sets animation steps (in ticks) when moving to a new selected item.

The default value is 30.

Parameters:

steps	The animation steps.

See also:

setEasingEquation, getAnimationSteps

setCircular

virtual void setCircular	(	bool	circular	)

Sets whether the list is circular (infinite) or not.

A circular list is a list where the first drawable re-appears after the last item in the list - and the last item in the list appears before the first item in the list.

Parameters:

circular	True if the list should be circular, false if the list should not be circular.

See also:

DrawableList::setCircular, getCircular

Reimplemented by: touchgfx::ScrollWheelWithSelectionStyle::setCircular

setDragAcceleration

void setDragAcceleration	(	uint16_t	acceleration	)

Sets drag acceleration times 10, so "10" means "1", "15" means "1.5".

10 makes the containers follow the finger, higher values makes the containers move faster. This can often be useful if the list is very long.

Parameters:

acceleration	The drag acceleration.

Note

The reason for multiplying the acceleration by 10 is to avoid introducing floating point arithmetic.

See also:

getDragAcceleration

setDrawableSize

virtual void setDrawableSize	(	int16_t	drawableSize ,
		int16_t	drawableMargin
		)

Sets drawables size.

The drawable is is the size of each drawable in the list in the set direction of the list (this is enforced by the DrawableList class). The specified margin is added above and below each item for spacing. The entire size of an item is thus size + 2 * spacing.

For a horizontal list each element will be drawableSize high and have the same width as set using setWidth(). For a vertical list each element will be drawableSize wide and have the same height as set using setHeight().

Parameters:

drawableSize	The size of the drawable.
drawableMargin	The margin around drawables (margin before and margin after).

See also:

setWidth, setHeight, setHorizontal

Reimplemented by: touchgfx::ScrollList::setDrawableSize, touchgfx::ScrollWheelWithSelectionStyle::setDrawableSize

setEasingEquation

void setEasingEquation	(	EasingEquation	equation	)

Sets easing equation when changing the selected item, for example via swipe or AnimateTo.

Parameters:

equation	The equation.

See also:

setAnimationSteps, getAnimationSteps

setHeight

virtual void setHeight	(	int16_t	height	)

Sets the height of this drawable.

Parameters:

height	The new height.

Note

For most Drawable widgets, changing this does normally not automatically yield a redraw.Also sets the height of the children.

Reimplements: touchgfx::Drawable::setHeight

Reimplemented by: touchgfx::ScrollList::setHeight, touchgfx::ScrollWheelWithSelectionStyle::setHeight

setHorizontal

virtual void setHorizontal	(	bool	horizontal	)

Sets a horizontal or vertical layout.

If parameter horizontal is set true, all drawables are arranged side by side. If horizontal is set false, the drawables are arranged above and below each other (vertically).

Parameters:

horizontal	True to align drawables horizontal, false to align drawables vertically.

Note

Default value is false, i.e. vertical layout.

See also:

DrawableList::setHorizontal, getHorizontal

Reimplemented by: touchgfx::ScrollWheelWithSelectionStyle::setHorizontal

setItemPressedCallback

void setItemPressedCallback	(	GenericCallback< int16_t > &	callback	)

Set Callback which will be called when a item is pressed.

Parameters:

callback	The callback.

setItemSelectedCallback

void setItemSelectedCallback	(	GenericCallback< int16_t > &	callback	)

Sets Callback which will be called when the selected item is clicked or dragged.

Parameters:

callback	The callback.

setMaxSwipeItems

void setMaxSwipeItems	(	uint16_t	maxItems	)

Sets maximum swipe items.

Often useful when there are e.g. five visible items on the screen and a swipe action should at most swipe the next/previous five items into view to achieve sort of a paging effect.

Parameters:

maxItems	The maximum items, 0 means "no limit" (which is also the default).

See also:

getMaxSwipeItems

setNumberOfItems

virtual void setNumberOfItems	(	int16_t	numberOfItems	)

Sets number of items in the DrawableList.

This forces all drawables to be updated to ensure that the content is correct. For example a date selector might switch number of days between 28, 29, 30, and 31 depending on the month. A circular list might show 27-28-29-30-31 and might need to update this to show 27-28-1-2-3.

Parameters:

numberOfItems	Number of items.

Note

The DrawableList is refreshed to reflect the change.

Reimplemented by: touchgfx::ScrollWheelWithSelectionStyle::setNumberOfItems

setOvershootPercentage

void setOvershootPercentage	(	uint8_t	percentage	)

Sets overshoot percentage when dragging a non-circular list.

This is the size relative to an item that can be dragged further than the actual list. Setting this to 50, it is possible to drag the list to show an empty space half the size of an item. Setting this to 0 prevents dragging further than the actual elements in the list.

Parameters:

percentage	The overshoot percentage.

See also:

getOvershootPercentage

setSwipeAcceleration

void setSwipeAcceleration	(	uint16_t	acceleration	)

Sets swipe acceleration (times 10).

Default value, if not set, is 10, i.e. 1.0.

Parameters:

acceleration	The acceleration times 10, so "9" means "0.9" and "75" means "7.5".

Note

The reason for multiplying the acceleration by 10 is to avoid introducing floating point arithmetic.

See also:

getSwipeAcceleration

setWidth

virtual void setWidth	(	int16_t	width	)

Sets the width of this drawable.

Parameters:

width	The new width.

Note

For most Drawable widgets, changing this does normally not automatically yield a redraw.Also sets the width of the children.

Reimplements: touchgfx::Drawable::setWidth

Reimplemented by: touchgfx::ScrollList::setWidth, touchgfx::ScrollWheelWithSelectionStyle::setWidth

stopAnimation

void stopAnimation	(			)

Stops an animation if one is ongoing.

Immediately moves to the item which is being animated to.

Protected Functions Documentation

animateToPosition

virtual void animateToPosition	(	int32_t	position ,
		int16_t	steps =-1
		)

Animate to a new position/offset using the given number of steps.

Parameters:

position	The new position.
steps	(Optional) The steps.

Reimplemented by: touchgfx::ScrollWheelBase::animateToPosition

getNearestAlignedOffset

virtual int32_t getNearestAlignedOffset	(	int32_t	offset	)

Gets nearest offset aligned to a multiple of itemSize.

Parameters:

offset	The offset.

Returns:

The nearest aligned offset.

Reimplemented by: touchgfx::ScrollList::getNearestAlignedOffset

getNormalizedOffset

int getNormalizedOffset	(	int	offset	)

Gets normalized offset from a given offset from 0 down to -numItems*itemSize.

Parameters:

offset	The offset.

Returns:

The normalized offset.

getOffset

virtual int32_t getOffset	(			)	const

Gets display offset of first item.

Returns:

The offset.

getPositionForItem

virtual int32_t getPositionForItem	(	int16_t	itemIndex	)

Get the position for an item.

The position should ensure that the item is in view as defined by the semantics of the actual scroll class. If the item is already in view, the current offset is returned and not the offset of the given item.

Parameters:

itemIndex	Zero-based index of the item.

Returns:

The position for item.

Reimplemented by: touchgfx::ScrollList::getPositionForItem, touchgfx::ScrollWheelBase::getPositionForItem

keepOffsetInsideLimits

virtual int32_t keepOffsetInsideLimits	(	int32_t	newOffset ,		const =0
		int16_t	overShoot		const =0
		)	const =0

Keep offset inside limits.

Return the new offset that is inside the limits of the scroll list, with the overShoot value added at both ends of the list.

Parameters:

newOffset	The new offset.
overShoot	The over shoot.

Returns:

The new offset inside the limits.

Reimplemented by: touchgfx::ScrollList::keepOffsetInsideLimits, touchgfx::ScrollWheelBase::keepOffsetInsideLimits

setOffset

virtual void setOffset	(	int32_t	offset	)

Sets display offset of first item.

Parameters:

offset	The offset.

Reimplemented by: touchgfx::ScrollWheelWithSelectionStyle::setOffset

Protected Attributes Documentation

animationEndedCallback

GenericCallback * animationEndedCallback

The animation ended callback.

currentAnimationState

AnimationState currentAnimationState

The current animation state.

defaultAnimationSteps

uint16_t defaultAnimationSteps

The animation steps.

distanceBeforeAlignedItem

int16_t distanceBeforeAlignedItem

The distance before aligned item.

dragAcceleration

uint16_t dragAcceleration

The drag acceleration x10.

draggableX

bool draggableX

Is the container draggable in the horizontal direction.

draggableY

bool draggableY

Is the container draggable in the vertical direction.

easingEquation

EasingEquation easingEquation

The easing equation used for animation.

gestureEnd

int gestureEnd

The gesture end.

gestureStart

int gestureStart

The gesture start.

gestureStep

int gestureStep

The current gesture step.

gestureStepsTotal

int gestureStepsTotal

The total gesture steps.

initialSwipeOffset

int32_t initialSwipeOffset

The initial swipe offset.

isPressed

bool isPressed

Is the container currently pressed (maybe show scrollbars)

isScrolling

bool isScrolling

Is the container scrolling (i.e. has overcome the initial larger drag that is required to initiate a scroll).

itemLockedInCallback

GenericCallback * itemLockedInCallback

The item locked in callback.

itemPressedCallback

GenericCallback< int16_t > * itemPressedCallback

The item pressed callback.

itemSelectedCallback

GenericCallback< int16_t > * itemSelectedCallback

The item selected callback.

itemSize

int16_t itemSize

Size of the item (including margin)

list

DrawableList list

The list.

maxSwipeItems

uint16_t maxSwipeItems

The maximum swipe items.

numberOfDrawables

int16_t numberOfDrawables

Number of drawables.

overshootPercentage

uint8_t overshootPercentage

The overshoot percentage when dragging.

swipeAcceleration

uint16_t swipeAcceleration

The swipe acceleration x10.

xClick

int16_t xClick

The x coordinate of a click.

yClick

int16_t yClick

The y coordinate of a click.