lvppCanvasFullColor Class Reference

Construct a canvas which uses FULL_COLOR rather than indexed color methods. More...

#include <lvpp.h>

Inheritance diagram for lvppCanvasFullColor:

Collaboration diagram for lvppCanvasFullColor:

Public Member Functions
	lvppCanvasFullColor (const char *fName, lv_coord_t x, lv_coord_t y, lv_coord_t w, lv_coord_t h, lv_color_t *providedBuffer=nullptr, lv_obj_t *parent=nullptr)
	Construct a new lvpp Canvas Full Color object.
virtual	~lvppCanvasFullColor ()
void	setbgColor (lv_color_t bgColor)
	Set the background color of the canvas.
void	drawPixel (lv_coord_t x, lv_coord_t y, lv_color_t color)
	Draw a single pixel on to the canvas.
void	drawRect (lv_coord_t x, lv_coord_t y, lv_coord_t w, lv_coord_t h, lv_coord_t borderThickness, lv_color_t borderColor, lv_color_t fillColor, uint16_t radius, lv_opa_t opa)
	Draw a rectangle on the canvas.
void	drawLine (lv_coord_t x1, lv_coord_t y1, lv_coord_t x2, lv_coord_t y2, lv_coord_t width, lv_color_t color)
	Draw a line on the canvas.
void	drawLabel (lv_coord_t x, lv_coord_t y, lv_coord_t maxW, lv_color_t color, const char *pText)
	Draw a text label onto the canvas.
Public Member Functions inherited from lvppBase
	lvppBase (const char *fName, const char *oType)
	Construct a new lvpp Base object.
	~lvppBase ()
void	createObj (lv_obj_t *o)
	Create the handlers and store the newly created object.
lv_obj_t *	getObj (void)
	Get the Obj object.
lv_obj_t *	getLabelObj (void)
	Get the label object.
virtual void	setSize (lv_coord_t width, lv_coord_t height)
	Set the Size object. Most of the time, LVGL does a great job of setting a sane size, but manipulation of things like the text or the font size can cause this to no longer be a good size. It is a common use pattern to instantiate a widget and then use setSize() and align() to place them in your user interface as needed.
void	align (lv_align_t align, lv_coord_t x_ofs, lv_coord_t y_ofs)
	Change the x/y location of the object.
void	setFontSize (uint8_t points)
	Set the Font Size for the object in simple 'points'.
void	setFont (const lv_font_t *pF)
	Set the Font to be used. This is a more complete/complex version of setFontSize(). The fact that the font pointer is required at least means the user knows the font exists.
void	setBGColor (lv_color_t color)
	Set the background color of the object.
void	setColorGradient (lv_color_t col1, lv_color_t col2, lv_grad_dir_t direction)
	Sets a Color Gradient from col1 to col2 in a vertical or horizontal direction. The gradient is place on the indicator for lvppBar, lvppSlider, and lvppArc. The graident is placed on the 'main' area of all other objects.
virtual void	setText (const char *pText)
	Set the Text for the primary text label. For a button, for instance, this is the text on top of the button.
std::string	getText ()
	Get the Text from the object/label and put it in a std::string.
void	setTextAlign (lv_align_t align, lv_coord_t xoff, lv_coord_t yoff)
	Set the Text Alignment. This allows the object's primary label to be moved from its 'center' position.
void	setTextColor (lv_color_t newColor)
	Set the Text Color of the primary label object.
void	setLabelJustificationAlignment (lv_text_align_t _align)
	Set the Label's text alignment (left/right/center)
void	setLabelColorizationEnabled (bool bEnable=true)
	Turn on or off inline text colorization. To use colors inline, simply use #RRGGBB in the text where the R, G, and B are hex values. Be sure to have a space before and after.
virtual void	setAdjText (const char *pText, lv_coord_t x_ofs=-10000, lv_coord_t y_ofs=-10000)
	Set the text for the adjacent text label. This label is not enabled by default. Setting this text will create and enable the adjacent label object. The label's position can be set, optionally, as well.
void	setAdjTextColor (lv_color_t newColor)
	Set the Adjacent text color.
void	setAdjBGColor (lv_color_t color)
	set the background color for the adjacent text
void	setAdjColorGradient (lv_color_t col1, lv_color_t col2, lv_grad_dir_t direction)
	Sets a Color Gradient from col1 to col2 in a vertical or horizontal direction.
void	setAdjFont (const lv_font_t *pF)
	Set the Font to be used for the adjacent text.
void	setAdjJustificationAlignment (lv_text_align_t _align)
	Set the adjacent Label's text alignment (left/right/center)
virtual void	onClicked ()
	Callback that derived objects can use to get notification when the object is clicked.
virtual void	internalOnClicked ()
	Internal version of the onClicked() callback which is used for other derived internal objects in the library.
virtual void	onValueChanged ()
	Callback that derived objects can use to get notification when the value changes of an object.
virtual void	internalOnValueChanged ()
	Internal version of the onValueChanged() callback which is used for other derived internal objects in the library.
void	setFriendlyName (const char *pName)
	Set the Friendly Name of the object. This is the name given in the constructor's fName parameter and is unlikely to be changed. However, it can be via this method.
std::string	getFriendlyName ()
	Get the Friendly Name of the object.
std::string	getObjType ()
	Get the Obj Type.
const char *	whoAmI (void)
	Utility useful for dumping the friendly name and object type if needed.
void	setCallbackOnClicked (std::function< void()> cbF)
	Uses a lambda callback for when an object is clicked.
void	setCallbackOnValueChanged (std::function< void()> cbF)
	Uses a lambda callback for when an object value changes.
virtual void	setNewParent (lv_obj_t *pNewParent)
	Changes the parent object on the fly. Used primarily for lvppScreen::addObject(). Sets parents of adjacent label, value label, and label appropriately.

Protected Attributes
lv_draw_rect_dsc_t *	pDscRect
lv_draw_line_dsc_t *	pDscLine
lv_draw_label_dsc_t *	pDscLabel
lv_point_t	twoPoints [2]
lv_color_t *	pBuffer
lv_coord_t	width
lv_coord_t	height
Protected Attributes inherited from lvppBase
lv_obj_t *	label
	Primary label.
lv_obj_t *	adjLabel
	For items that have a label 'nearby' (adjacent label)
std::function< void()>	cbOnClicked =nullptr
	Start without a lambda callback.
std::function< void()>	cbOnValueChanged =nullptr
	Start without a lambda callback.
lv_obj_t *	obj
	The LVGL object that was created for this widget.
lv_obj_t *	objParent
	Any parent object (following same principle as LVGL here)
std::string	objType
std::string	friendlyName
lv_style_t	style_obj
	Main style object - unsure if I'm handling all of the style bit correctly.

Additional Inherited Members
Static Public Member Functions inherited from lvppBase
static const char *	getEventName (lv_event_code_t code)
	Get the Event Name from a given event code. Translate it to text, essentially.
static bool	isUnknownCode (lv_event_code_t code)
	Check to see if an event code is valid or not. Utility function.
Protected Member Functions inherited from lvppBase
void	setObjType (const char *pType)
void	baseEventHandler (lv_event_t *event)
	Main event handler loop for all events. This handler makes calls for onClicked() and onValueChanged()
virtual void	eventHandler (lv_event_t *event)
	Any events not handled by baseEventHandler come here. Can be overridden by a derived class.
Static Protected Member Functions inherited from lvppBase
static void	lvCallback (lv_event_t *event)
	Static member to handle all inbound callback events. Used to "route" event handling to the appropriate C++ object.
static void	initEventNames (void)
	One-time initialization of the event names array.
Static Protected Attributes inherited from lvppBase
static bool	bEventNamesInitComplete = false
	Status of the event names table to avoid re-processing.

Detailed Description

Construct a canvas which uses FULL_COLOR rather than indexed color methods.

Canvas drawing is very powerful in LVGL, but only when a full color canvas is available. In many smaller CPUs, full color isn't an option due to the sheer size of needing to have a buffer which is width * height * 4-bytes plus a bit more. LVGL has some great facilities around drawing rectangles, lines, and labels with really nice options like rounded ends, line thicknesses, and other style attributes. Many of these functions simply do not work in the indexed color world. So, this class implements the full color functions while the lvppCanvasIndexed implements a stripped down version of these functions within the reduced color set. See lvppCanvasIndexed for more detail on what's provided and how it works.

Constructor & Destructor Documentation

lvppCanvasFullColor()

lvppCanvasFullColor::lvppCanvasFullColor	(	const char *	fName,
		lv_coord_t	x,
		lv_coord_t	y,
		lv_coord_t	w,
		lv_coord_t	h,
		lv_color_t *	providedBuffer = nullptr,
		lv_obj_t *	parent = nullptr
	)

Construct a new lvpp Canvas Full Color object.

Parameters

fName	Internal object name. This is generally used in findObj() or lvppScreen
x,y	Top-left starting point of the canvas on the display.
w,h	Width and height of the canvas referenced from x and y.
providedBuffer	If provided, a non-null value will cause the constructor to not allocate its own buffer. This is helpful when a series of screens intend to share a common canvas with no drawing changes between them.
parent	If provided, the parent of the object. This is a real LVGL lv_obj_t pointer

~lvppCanvasFullColor()

lvppCanvasFullColor::~lvppCanvasFullColor ( )

virtual

Member Function Documentation

drawLabel()

void lvppCanvasFullColor::drawLabel	(	lv_coord_t	x,
		lv_coord_t	y,
		lv_coord_t	maxW,
		lv_color_t	color,
		const char *	pText
	)

Draw a text label onto the canvas.

Parameters

x,y	Starting point for the drawing of the text
maxW	Maximum width in pixels of the drawing.
color	Color of the text to be drawn
pText	Text to be drawn

Todo:

This likely needs more thought. It takes no account for font sizes at a minimum. Not enough consideration has been given to how this would be used quite yet.

drawLine()

void lvppCanvasFullColor::drawLine	(	lv_coord_t	x1,
		lv_coord_t	y1,
		lv_coord_t	x2,
		lv_coord_t	y2,
		lv_coord_t	width,
		lv_color_t	color
	)

Draw a line on the canvas.

Parameters

x1,y1	Starting point of the line to be drawn.
x2,y2	Ending point of the line to be drawn.
width	Width of the line to be drawn in pixels.
color	Color of the line to be drawn.

drawPixel()

void lvppCanvasFullColor::drawPixel	(	lv_coord_t	x,
		lv_coord_t	y,
		lv_color_t	color
	)

Draw a single pixel on to the canvas.

Parameters

x	X location
y	Y location
color	Color to be drawn.

drawRect()

void lvppCanvasFullColor::drawRect	(	lv_coord_t	x,
		lv_coord_t	y,
		lv_coord_t	w,
		lv_coord_t	h,
		lv_coord_t	borderThickness,
		lv_color_t	borderColor,
		lv_color_t	fillColor,
		uint16_t	radius,
		lv_opa_t	opa
	)

Draw a rectangle on the canvas.

Parameters

x,y	Starting point of the rectangle
w,h	Width and height of the rectangle
borderThickness	Thickness of the rectangle in pixels.
borderColor	Color of the rectangle's border lines.
fillColor	Color to fill in the rectangle.
radius	The outside radius for a non-square set of corners.
opa	Opacity if opacity is enabled for your configuration.

setbgColor()

void lvppCanvasFullColor::setbgColor

(

lv_color_t

bgColor

)

Set the background color of the canvas.

Parameters

bgColor

The color to be used in painting the background. This is an lv_color_t from LVGL.

Member Data Documentation

height

lv_coord_t lvppCanvasFullColor::height

protected

pBuffer

lv_color_t* lvppCanvasFullColor::pBuffer

protected

pDscLabel

lv_draw_label_dsc_t* lvppCanvasFullColor::pDscLabel

protected

pDscLine

lv_draw_line_dsc_t* lvppCanvasFullColor::pDscLine

protected

pDscRect

lv_draw_rect_dsc_t* lvppCanvasFullColor::pDscRect

protected

twoPoints

lv_point_t lvppCanvasFullColor::twoPoints[2]

protected

width

lv_coord_t lvppCanvasFullColor::width

protected

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The documentation for this class was generated from the following files:

• src/lvpp.h
• src/lvppCanvas.cpp