CacheableContainer

touchgfx/containers/CacheableContainer.hpp

A CacheableContainer can be seen as a regular Container, i.e. a Drawable that can have child nodes. The z-order of children is determined by the order in which Drawables are added to the container - the Drawable added last will be front-most on the screen.

The important difference is that a CacheableContainer can also render its content to a dynamic bitmap which can then be used as a texture in subsequent drawing operations, either as a simple Image or in a TextureMapper. If the bitmap format of the dynamic bitmap differs from the format of the current LCD, the LCD from drawing the bitmap must be setup using HAL::setAuxiliaryLCD().

See: Container, Bitmap, Image, TextureMapper

Inherits from: Container, Drawable

Public Functions

	CacheableContainer()
void	enableCachedMode(bool enable)
	Toggle cached mode on and off.
uint8_t	getAlpha() const
	Gets the current alpha value of the widget.
BitmapId	getCacheBitmap() const
	Get the dynamic bitmap used by the CacheableContainer.
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 subregion of this drawable is redrawn.
bool	isChildInvalidated() const
	Queries the CacheableContainer whether any child widget has been invalidated.
void	setAlpha(uint8_t newAlpha)
	Sets the opacity (alpha value).
void	setCacheBitmap(BitmapId bitmapId)
	Set the dynamic bitmap into which the container content will be rendered.
bool	setSolidRect(const Rect & solidRect) const
	Set the solid area on the dynamic bitmap assigned to the CacheableContainer.
void	updateCache()
	Render the container into the attached dynamic bitmap.
void	updateCache(const Rect & rect)
	Render the container into the attached dynamic bitmap.

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	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.
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

CacheableContainer

CacheableContainer	(			)

enableCachedMode

void enableCachedMode	(	bool	enable	)

Toggle cached mode on and off.

The CacheableContainer behaves just like a regular Container when cached mode is turned off.

Parameters:

enable	Enable or disable cached mode.

getAlpha

uint8_t getAlpha	(			)	const

Gets the current alpha value of the widget.

The alpha value is in range 255 (solid) to 0 (invisible).

Returns:

The current alpha value.

See also:

setAlpha

getCacheBitmap

BitmapId getCacheBitmap	(			)	const

Get the dynamic bitmap used by the CacheableContainer.

Returns:

the id of the assigned bitmap or BITMAP_INVALID if no bitmap has been assigned.

See also:

setCacheBitmap

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

invalidateRect

virtual void invalidateRect	(	Rect &	invalidatedArea	)

Request that a subregion of this drawable is redrawn.

Will recursively traverse the children. When this function returns, the specified invalidated area has been redrawn for all appropriate Drawables covering the region.

Parameters:

invalidatedArea	The area of this drawable to redraw expressed in coordinates relative to its parent (e.g. to request a complete redraw, invalidatedArea will be (0, 0, width, height).

Reimplements: touchgfx::Drawable::invalidateRect

isChildInvalidated

bool isChildInvalidated	(			)	const

Queries the CacheableContainer whether any child widget has been invalidated.

Returns:

True if a child widget has been invalidated and false otherwise.

setAlpha

void setAlpha	(	uint8_t	newAlpha	)

Sets the opacity (alpha value).

This can be used to fade it away by gradually decreasing the alpha value from 255 (solid) to 0 (invisible).

Parameters:

newAlpha	The new alpha value. 255=solid, 0=invisible.

Note

The user code must call invalidate() in order to update the display.The alpha is only applied when cached mode is enabled.

See also:

getAlpha enableCachedMode

setCacheBitmap

void setCacheBitmap	(	BitmapId	bitmapId	)

Set the dynamic bitmap into which the container content will be rendered.

The format of the bitmap must be the same as the current LCD or the same as the auxiliary LCD setup using HAL::setAuxiliaryLCD.

Parameters:

bitmapId	Id of the dynamic bitmap to serve as a render target.

See also:

updateCache, getCacheBitmap, HAL::setAuxiliaryLCD

setSolidRect

bool setSolidRect	(	const Rect &	solidRect	)

Set the solid area on the dynamic bitmap assigned to the CacheableContainer.

Parameters:

solidRect	The rectangle of th CacheableContainer that is solid.

Returns:

true if the operation succeeds, false otherwise.

updateCache

void updateCache	(			)

Render the container into the attached dynamic bitmap.

See also:

setCacheBitmap

updateCache

void updateCache	(	const Rect &	rect	)

Render the container into the attached dynamic bitmap.

Only the specified Rect region is updated.

Parameters:

rect	Region to update.

See also:

setCacheBitmap