GraphElementHistogram

touchgfx/widgets/graph/GraphElements.hpp

The GraphElementHistogram is used to draw blocks from the x axis to the data point in the graph. If more graphs are placed on top of each other, the histogram can be moved slightly to the left/right.

Note: Historgram boxes are drawn using LCD::fillRect for higher performance.

Inherits from: AbstractGraphElementNoCWR, AbstractGraphElement, CanvasWidget, Widget, Drawable

Public Functions

virtual void	draw(const Rect & invalidatedArea) const
	Draws the given invalidated area.
FORCE_INLINE_FUNCTION int16_t	getBarOffset() const
	Gets bar offset (horizontally).
FORCE_INLINE_FUNCTION uint16_t	getBarWidth() const
	Gets bar width of the histogram columns.
FORCE_INLINE_FUNCTION float	getBaselineAsFloat() const
	Gets the base previously set using setBaseline.
FORCE_INLINE_FUNCTION int	getBaselineAsInt() const
	Gets the base previously set using setBaseline.
FORCE_INLINE_FUNCTION int	getBaselineScaled() const
	Gets the base previously set using setBaseline.
FORCE_INLINE_FUNCTION int	getScale() const
	Gets the scaling factor set using setScale.
	GraphElementHistogram()
virtual void	invalidateGraphPointAt(int16_t index)
	Invalidate the point at the given index.
FORCE_INLINE_FUNCTION void	setBarOffset(int16_t offset)
	Sets bar offset (horizontally) in pixels.
FORCE_INLINE_FUNCTION void	setBarWidth(uint16_t width)
	Sets bar width of each histogram column in pixels.
FORCE_INLINE_FUNCTION void	setBaseline(float baseline)
	Sets the base of the area drawn.
FORCE_INLINE_FUNCTION void	setBaseline(int baseline)
	Sets the base of the area drawn.
FORCE_INLINE_FUNCTION void	setBaselineScaled(int baseline)
	Sets the base of the area drawn.
FORCE_INLINE_FUNCTION void	setScale(int scale)
	Sets a scaling factor to be multiplied on the baseline.

Protected Attributes

int16_t	barOffset
	The horizontal bar offset.
uint16_t	barWidth
	Width of each bar.
int	dataScale
	The scaling factor.
int	yBaseline
	The baseline.

Additional inherited members

Public Functions inherited from AbstractGraphElementNoCWR

	AbstractGraphElementNoCWR()
virtual bool	drawCanvasWidget(const Rect & invalidatedArea) const
	Draw canvas widget for the given invalidated area.
virtual colortype	getColor() const
	Gets the color of the graph element.
virtual void	setColor(colortype newColor)
	Sets the color of the graph element.

Protected Functions inherited from AbstractGraphElementNoCWR

void	normalizeRect(Rect & r) const
	Normalize rectangle by changing a rectangle with negative width or height to a rectangle with positive width or height at the correct position.

Protected Attributes inherited from AbstractGraphElementNoCWR

colortype	color
	The currently assigned color.

Public Functions inherited from AbstractGraphElement

	AbstractGraphElement()
	Default constructor.

Protected Functions inherited from AbstractGraphElement

FORCE_INLINE_FUNCTION int	convertToGraphScaleX(const AbstractDataGraph * graph, int value, int scale) const
	Converts the value to the proper X scale of the graph.
FORCE_INLINE_FUNCTION int	convertToGraphScaleY(const AbstractDataGraph * graph, int value, int scale) const
	Converts the value to the proper Y scale of the graph.
FORCE_INLINE_FUNCTION AbstractDataGraph *	getGraph() const
	Gets a pointer to the the graph containing the GraphElement.
FORCE_INLINE_FUNCTION int	getIndexToXAxis(const AbstractDataGraph * graph, const int valueScaled, const int labelScaled) const
	Convert the given valueScaled (index) to x axis value.
FORCE_INLINE_FUNCTION CWRUtil::Q5	indexToScreenXQ5(const AbstractDataGraph * graph, int16_t index) const
	Gets screen x coordinate for a specific data point added to the graph.
FORCE_INLINE_FUNCTION CWRUtil::Q5	indexToScreenYQ5(const AbstractDataGraph * graph, int16_t index) const
	Gets screen y coordinate for a specific data point added to the graph.
bool	isCenterInvisible(const AbstractDataGraph * graph, int16_t index) const
	Query if the center of a given data point index is visible inside the graph area.
Rect	rectAround(CWRUtil::Q5 xQ5, CWRUtil::Q5 yQ5, CWRUtil::Q5 diameterQ5) const
	Find the screen rectangle around a given point with the specified diameter.
Rect	rectFromQ5Coordinates(CWRUtil::Q5 screenXminQ5, CWRUtil::Q5 screenYminQ5, CWRUtil::Q5 screenXmaxQ5, CWRUtil::Q5 screenYmaxQ5) const
	Find the screen rectangle containing the Q5 screen rectangle by rounding the coordinates up/down.
FORCE_INLINE_FUNCTION CWRUtil::Q5	roundQ5(CWRUtil::Q5 q5) const
	Round the given CWRUtil::Q5 to the nearest integer and return it as a CWRUtil::Q5 instead of an integer.
FORCE_INLINE_FUNCTION CWRUtil::Q5	valueToScreenXQ5(const AbstractDataGraph * graph, int x) const
	Gets graph screen x for x value.
FORCE_INLINE_FUNCTION CWRUtil::Q5	valueToScreenYQ5(const AbstractDataGraph * graph, int y) const
	Gets graph screen y for y value.
FORCE_INLINE_FUNCTION bool	xScreenRangeToIndexRange(const AbstractDataGraph * graph, int16_t xMin, int16_t xMax, int16_t & indexMin, int16_t & indexMax) const
	Gets graph element range for screen x coordinate range.

Public Functions inherited from CanvasWidget

	CanvasWidget()
virtual bool	drawCanvasWidget(const Rect & invalidatedArea) const =0
	Draw canvas widget for the given invalidated area.
virtual uint8_t	getAlpha() const
	Gets the current alpha value of the widget.
virtual Rect	getMinimalRect() const
	Gets minimal rectangle containing the shape drawn by this widget.
const AbstractPainter *	getPainter() const
	Gets the current painter for the CanvasWidget.
virtual Rect	getSolidRect() const
	Gets the largest solid (non-transparent) rectangle.
virtual void	invalidate() const
	Invalidates the area covered by this CanvasWidget.
virtual void	setAlpha(uint8_t newAlpha)
	Sets the opacity (alpha value).
void	setPainter(const AbstractPainter & painter)
	Sets a painter for the CanvasWidget.

Protected Attributes inherited from CanvasWidget

uint8_t	alpha
	The Alpha for this CanvasWidget.

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	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.
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.
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	)

Draws the given invalidated area.

If the underlying CanvasWidgetRenderer fail to render the widget (if the widget is too complex), the invalidated area is cut into smaller slices (horizontally) which are then drawn separately. If drawing a single raster line fails, that line is considered too complex and skipped (it is left blank/transparent) and drawing continues on the next raster line.

If drawing has failed at least once, which means that the number of horizontal lines draw has been reduced, the number of successfully drawn horizontal lines is remembered for the next invocation of draw(). A future call to draw() would then start off with the reduced number of horizontal lines to prevent potentially drawing the canvas widget in vain, as happened previously in draw().

Parameters:

invalidatedArea	The invalidated area.

Note

Subclasses of CanvasWidget should implement drawCanvasWidget(), not draw(). The term "too complex" means that the size of the buffer (assigned to CanvasWidgetRenderer using CanvasWidgetRenderer::setupBuffer()) is too small.

See also:

drawCanvasWidget

Reimplements: touchgfx::CanvasWidget::draw

getBarOffset

FORCE_INLINE_FUNCTION int16_t getBarOffset	(			)	const

Gets bar offset (horizontally).

Bar offset can be used when there are two different histogram graphs on top of each other to prevent one histogram from covering the other.

Returns:

The bar offset.

See also:

setBarOffset

getBarWidth

FORCE_INLINE_FUNCTION uint16_t getBarWidth	(			)	const

Gets bar width of the histogram columns.

Returns:

The bar width.

See also:

setBarWidth

getBaselineAsFloat

FORCE_INLINE_FUNCTION float getBaselineAsFloat	(			)	const

Gets the base previously set using setBaseline.

Returns:

The base value.

See also:

setBaseline

getBaselineAsInt

FORCE_INLINE_FUNCTION int getBaselineAsInt	(			)	const

Gets the base previously set using setBaseline.

Returns:

The base value.

See also:

setBaseline

getBaselineScaled

FORCE_INLINE_FUNCTION int getBaselineScaled	(			)	const

Gets the base previously set using setBaseline.

Returns:

The base value.

Note

The baseline returned here is left unscaled.

See also:

setBaseline

getScale

FORCE_INLINE_FUNCTION int getScale	(			)	const

Gets the scaling factor set using setScale.

Returns:

The scaling factor.

See also:

setScale

GraphElementHistogram

GraphElementHistogram	(			)

invalidateGraphPointAt

virtual void invalidateGraphPointAt	(	int16_t	index	)

Invalidate the point at the given index.

This allows a graph element to only invalidate the minimum rectangle required for the given index. The Graph will call this function before and after changing a point to ensure that both the old and the new area are redrawn (invalidated).

Parameters:

index	Zero-based index of the point.

Reimplements: touchgfx::AbstractGraphElement::invalidateGraphPointAt

setBarOffset

FORCE_INLINE_FUNCTION void setBarOffset	(	int16_t	offset	)

Sets bar offset (horizontally) in pixels.

This can be used when there are two different histogram graphs on top of each other to prevent one histogram from covering the other.

Parameters:

offset	The offset.

See also:

getBarOffset

setBarWidth

FORCE_INLINE_FUNCTION void setBarWidth	(	uint16_t	width	)

Sets bar width of each histogram column in pixels.

Parameters:

width	The width.

See also:

getBarWidth

setBaseline

FORCE_INLINE_FUNCTION void setBaseline	(	float	baseline	)

Sets the base of the area drawn.

Normally, the base is 0 which means that the area is drawn below positive y values and above negative y values. Setting the base to a very high number will cause the area above the graph to be drawn. Setting the base to a very low number will cause the area below the graph to be drawn (even for negative numbers, which are higher than the base value).

Parameters:

baseline	The base value.

See also:

getBaselineAsInt, getBaselineAsFloat

setBaseline

FORCE_INLINE_FUNCTION void setBaseline	(	int	baseline	)

Sets the base of the area drawn.

Normally, the base is 0 which means that the area is drawn below positive y values and above negative y values. Setting the base to a very high number will cause the area above the graph to be drawn. Setting the base to a very low number will cause the area below the graph to be drawn (even for negative numbers, which are higher than the base value).

Parameters:

baseline	The base value.

See also:

getBaselineAsInt, getBaselineAsFloat

setBaselineScaled

FORCE_INLINE_FUNCTION void setBaselineScaled	(	int	baseline	)

Sets the base of the area drawn.

Normally, the base is 0 which means that the area is drawn below positive y values and above negative y values. Setting the base to a very high number will cause the area above the graph to be drawn. Setting the base to a very low number will cause the area below the graph to be drawn (even for negative numbers, which are higher than the base value).

Parameters:

baseline	The base value.

Note

The baseline set here must already be scaled.

See also:

getBaselineAsInt, getBaselineAsFloat

setScale

FORCE_INLINE_FUNCTION void setScale	(	int	scale	)

Sets a scaling factor to be multiplied on the baseline.

Any already set baseline will be updated to the new correctly scaled value. To avoid this, use setBaselineScaled() after setting scale.

Parameters:

scale	The scaling factor.

See also:

getScale

Protected Attributes Documentation

barOffset

int16_t barOffset

The horizontal bar offset.

barWidth

uint16_t barWidth

Width of each bar.

dataScale

int dataScale

The scaling factor.

yBaseline

int yBaseline

The baseline.