PixelDataWidget

touchgfx/widgets/PixelDataWidget.hpp

A widget for displaying a buffer of pixel data. This can also be though of as a dynamic bitmap where the dimensions of the bitmap is the same as the dimensions of the widget and the actual bitmap data can be set and updated dynamically. The size of the buffer must match the number of bytes required for the widget calculated as WIDTH x HEIGHT x BYTES_PER_PIXEL. If the LCD is 16 bit per pixel the buffer must hold 2 bytes for each pixel. If the LCD is 24 bit the buffer must hold 3 bytes for each pixel.

Inherits from: Widget, Drawable

Public Functions

virtual void	draw(const Rect & invalidatedArea) const
	Draw this drawable.
uint8_t	getAlpha() const
	Gets the current alpha value of the widget.
Bitmap::BitmapFormat	getBitmapFormat() const
	Get the format of the pixel data previously set using setBitmapFormat().
uint8_t *	getPixelData() const
	Get the pixel data memory pointer, previously set with setPixelData().
virtual Rect	getSolidRect() const
	Get (the largest possible) rectangle that is guaranteed to be solid (opaque).
virtual void	invalidateContent() const
	Tell the framework that the contents of the Drawable needs to be redrawn.
	PixelDataWidget()
void	setAlpha(uint8_t newAlpha)
	Sets the opacity (alpha value).
void	setBitmapFormat(Bitmap::BitmapFormat bitmapFormat)
	Set the format of the pixel data.
void	setPixelData(uint8_t *const data)
	Set the pixel data to display.

Protected Attributes

uint8_t	alpha
	The Alpha for this widget.
uint8_t *	buffer
	The buffer where the pixels are copied from.
Bitmap::BitmapFormat	format
	The pixel format for the data.

Additional inherited members

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	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.
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

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

getBitmapFormat

Bitmap::BitmapFormat getBitmapFormat	(			)	const

Get the format of the pixel data previously set using setBitmapFormat().

Returns:

The bitmap format.

See also:

setBitmapFormat

getPixelData

uint8_t * getPixelData	(			)	const

Get the pixel data memory pointer, previously set with setPixelData().

Returns:

The pixel data.

See also:

setPixelData, setBitmapFormat

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

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

PixelDataWidget

PixelDataWidget	(			)

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.

See also:

getAlpha

setBitmapFormat

void setBitmapFormat	(	Bitmap::BitmapFormat	bitmapFormat	)

Set the format of the pixel data.

The supported formats depend on the display type. For example grayscale displays do not support color images.

Parameters:

bitmapFormat	Describes the format to use when reading the pixel data.

See also:

getBitmapFormat

setPixelData

void setPixelData	(	uint8_t *const	data	)

Set the pixel data to display.

The given pointer must contain WIDTH x HEIGHT x BYTES_PER_PIXEL bytes of addressable image data.

Parameters:

data	Image data.

See also:

getPixelData, setBitmapFormat

Protected Attributes Documentation

alpha

uint8_t alpha

The Alpha for this widget.

buffer

uint8_t * buffer

The buffer where the pixels are copied from.

format

Bitmap::BitmapFormat format

The pixel format for the data.