lvppBase is the root of the C++ library LVGLPlusPlus. It strives to create consistent ways to manipulate a variety of LVGL-based widgets in a consistent manner - hiding the details away from the user where possible. More...

#include <lvppBase.h>

Inheritance diagram for lvppBase:

[legend]

Public Member Functions
	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.

Static Public Member Functions
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
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
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.

Protected Attributes
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.

Static Protected Attributes
static bool	bEventNamesInitComplete = false
	Status of the event names table to avoid re-processing.

Detailed Description

lvppBase is the root of the C++ library LVGLPlusPlus. It strives to create consistent ways to manipulate a variety of LVGL-based widgets in a consistent manner - hiding the details away from the user where possible.

The topmost concepts for lvppBase are:

Having a handle to an LVGL object 'obj' which gets created (and named) for each widget.
Event handling for each widget is handled by the class and callbacks are used to give the user the ability to take action on changes or events.
Lambda functions are used in some cases to allow users to utilize the widget class without having to derive their own class from it for the sole purpose of a callback.
A main 'label' is defined for all base widgets.
An options 'adjacent label' can be used to enable a separate label that acts (often) as a label for the item. Think of a dropdown list that needs a nearby label to tell the user what this dropdown is intended for.
Font setting
Background color setting
Size and location/alignment of the widget
Setting of text for the main label as well as ancillary labels.

Constructor & Destructor Documentation

◆ lvppBase()

lvppBase::lvppBase	(	const char *	fName,
		const char *	oType
	)

Construct a new lvpp Base object.

Parameters

fName	Internal object name. This is generally used in findObj() or lvppScreen
oType	The type of the object being created. This is primarily internal, but can be used to know the category/type of the object and can be obtained via getObjType() if needed.

◆ ~lvppBase()

lvppBase::~lvppBase ( )

Member Function Documentation

◆ align()

void lvppBase::align	(	lv_align_t	align,
		lv_coord_t	x_ofs,
		lv_coord_t	y_ofs
	)

Change the x/y location of the object.

Parameters

align	This is an LVGL notion of alignment type. It is a very rich concept of alignment that does not simply use x/y screen coordinates but uses the x/y as an offset from some other 'anchor'. In concrete terms, this is one of LV_ALIGN_CENTER, LV_ALIGN_TOP_MID, LV_ALIGN_BOTTON_RIGHT, etc.
x_ofs	The x offset from the align point.
y_ofs	The y offset from the align point.

◆ baseEventHandler()

void lvppBase::baseEventHandler ( lv_event_t * event )

protected

Main event handler loop for all events. This handler makes calls for onClicked() and onValueChanged()

Parameters

event LVGL lv_event_t type event to be handled.

◆ createObj()

void lvppBase::createObj ( lv_obj_t * o )

Create the handlers and store the newly created object.

The pattern here is that any derived widget type will, in its constructor, call createObj() with a pointer to the appropriate LVGL object type. For instance createObj(lv_dropdown_create(objParent)); This effectively make it the responsibility of the derived class to create the right type of object and pass it to createObj() so that the base class can hang on to that handle and then setup event callbacks for the object.

Parameters

o	The lv_obj_t pointer created by the derived class. Might this be better named storeNewObj() - but lots of refacotring to do if so.

◆ eventHandler()

virtual void lvppBase::eventHandler ( lv_event_t * event )

inlineprotectedvirtual

Any events not handled by baseEventHandler come here. Can be overridden by a derived class.

Parameters

event LVGL lv_event_t type event to be handled.

◆ getEventName()

const char * lvppBase::getEventName ( lv_event_code_t code )

static

Get the Event Name from a given event code. Translate it to text, essentially.

Parameters

code	An lv_event_code_t type from LVGL.

Returns: const char* Pointer to a string with the textual description of the code type.

◆ getFriendlyName()

std::string lvppBase::getFriendlyName ( )

inline

Get the Friendly Name of the object.

Returns: std::string of the internal friendly name of the object.

◆ getLabelObj()

lv_obj_t * lvppBase::getLabelObj ( void )

inline

Get the label object.

Returns: lv_obj_t* Returns the LVGL lv_obj_t for the actual label object. Great for more advanced users who may wish to manipulate the label more fully outside of the lvpp* class library.

◆ getObj()

lv_obj_t * lvppBase::getObj ( void )

inline

Get the Obj object.

Returns: lv_obj_t* Returns the LVGL lv_obj_t for the actual widget/object. Great for more advanced users who may wish to manipulate the object more fully outside of the lvpp* class library.

◆ getObjType()

std::string lvppBase::getObjType ( )

inline

Get the Obj Type.

Returns: std::string of the internal object type. This is what is given in the constructor as oType. It can be used to determine the type of an object without the need for RTTI library support and dynamic_cast<> or other such RTTI support methodologies.

◆ getText()

std::string lvppBase::getText ( )

Get the Text from the object/label and put it in a std::string.

Returns: std::string return the text into a string.

◆ initEventNames()

void lvppBase::initEventNames ( void )

staticprotected

One-time initialization of the event names array.

◆ internalOnClicked()

virtual void lvppBase::internalOnClicked ( )

inlinevirtual

Internal version of the onClicked() callback which is used for other derived internal objects in the library.

Reimplemented in lvppCycleButton.

◆ internalOnValueChanged()

virtual void lvppBase::internalOnValueChanged ( )

inlinevirtual

Internal version of the onValueChanged() callback which is used for other derived internal objects in the library.

Reimplemented in lvppBaseWithValue.

◆ isUnknownCode()

bool lvppBase::isUnknownCode ( lv_event_code_t code )

static

Check to see if an event code is valid or not. Utility function.

Parameters

code	Event code from LVGL

Returns: If the event code has a valid lookup, returns true.

◆ lvCallback()

void lvppBase::lvCallback ( lv_event_t * event )

staticprotected

Static member to handle all inbound callback events. Used to "route" event handling to the appropriate C++ object.

Parameters

event An LVGL lv_event_t event object pointer to be handled.

◆ onClicked()

virtual void lvppBase::onClicked ( )

inlinevirtual

Callback that derived objects can use to get notification when the object is clicked.

◆ onValueChanged()

virtual void lvppBase::onValueChanged ( )

inlinevirtual

Callback that derived objects can use to get notification when the value changes of an object.

Reimplemented in lvppFullImageToggleButton.

◆ setAdjBGColor()

void lvppBase::setAdjBGColor ( lv_color_t color )

set the background color for the adjacent text

Parameters

color lv_color_t to describe the background color.

◆ setAdjColorGradient()

void lvppBase::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.

Parameters

col1	First lv_color_t color in the gradient
col2	Second lv_color_t color in the gradient
direction	gradient color runs col1->col2 either LV_GRAD_DIR_VER (top to bottom) or LV_GRAD_DIR_HOR (left to right)

◆ setAdjFont()

void lvppBase::setAdjFont ( const lv_font_t * pF )

Set the Font to be used for the adjacent text.

Parameters

pF	A pointer to a valid lv_font_t to be used for the object.

◆ setAdjJustificationAlignment()

void lvppBase::setAdjJustificationAlignment ( lv_text_align_t _align )

Set the adjacent Label's text alignment (left/right/center)

Parameters

_align an lv_text_align_t like LV_TEXT_ALIGN_CENTER

◆ setAdjText()

void lvppBase::setAdjText	(	const char *	pText,
		lv_coord_t	x_ofs = `-10000`,
		lv_coord_t	y_ofs = `-10000`
	)

virtual

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.

Parameters

pText	Pointer to the text to use.
x_ofs	X offset from the center of the main object.
y_ofs	Y offset from the center of the main object.

◆ setAdjTextColor()

void lvppBase::setAdjTextColor ( lv_color_t newColor )

Set the Adjacent text color.

Parameters

newColor lv_color_t value for the new color of the adjacent text

◆ setBGColor()

void lvppBase::setBGColor ( lv_color_t color )

Set the background color of the object.

Parameters

color lv_color_t color to be used for the background.

Todo:: I think this add_style needs to go away and an 'invalidate' should be used instead.

◆ setCallbackOnClicked()

void lvppBase::setCallbackOnClicked ( std::function< void()> cbF )

inline

Uses a lambda callback for when an object is clicked.

This method allows users to instantiate most objects without deriving their own class from them. They can instantiate the object, set its font, size, alignment, and text all using the built in methods and they can receive a callback through the use of this lambda callback methodology.

Parameters

cbF	This is a std::function<> lambda defining the callback 'inline'.

◆ setCallbackOnValueChanged()

void lvppBase::setCallbackOnValueChanged ( std::function< void()> cbF )

inline

Uses a lambda callback for when an object value changes.

This method allows users to instantiate most objects without deriving their own class from them. They can instantiate the object, set its font, size, alignment, and text all using the built in methods and they can receive a callback through the use of this lambda callback methodology.

Parameters

cbF	This is a std::function<> lambda defining the callback 'inline'.

◆ setColorGradient()

void lvppBase::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.

Parameters

col1	First lv_color_t color in the gradient
col2	Second lv_color_t color in the gradient
direction	gradient color runs col1->col2 either LV_GRAD_DIR_VER (top to bottom) or LV_GRAD_DIR_HOR (left to right)

◆ setFont()

void lvppBase::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.

Parameters

pF	A pointer to a valid lv_font_t to be used for the object.

◆ setFontSize()

void lvppBase::setFontSize ( uint8_t points )

Set the Font Size for the object in simple 'points'.

NOTE: This makes easy work of changing font sizes, but its downfall is that the size can be given for font sizes that don't exist for several reasons. Be forewarned.

Parameters

points The desired point size for the object.

Todo:: Possibly return a bool for errant point values or for requests of point sizes that weren't compiled in?

◆ setFriendlyName()

void lvppBase::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.

Parameters

pName pointer to a new friendly name.

◆ setLabelColorizationEnabled()

void lvppBase::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.

Parameters

bEnable Turn on or off inline text colorization. Default is true.

◆ setLabelJustificationAlignment()

void lvppBase::setLabelJustificationAlignment ( lv_text_align_t _align )

Set the Label's text alignment (left/right/center)

Parameters

_align an lv_text_align_t like LV_TEXT_ALIGN_CENTER

◆ setNewParent()

void lvppBase::setNewParent ( lv_obj_t * pNewParent )

virtual

Changes the parent object on the fly. Used primarily for lvppScreen::addObject(). Sets parents of adjacent label, value label, and label appropriately.

Parameters

pNewParent pointer to the new parent.

Reimplemented in lvppBaseWithValue.

◆ setObjType()

void lvppBase::setObjType ( const char * pType )

inlineprotected

◆ setSize()

void lvppBase::setSize	(	lv_coord_t	width,
		lv_coord_t	height
	)

virtual

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.

Parameters

width	New width of the widget.
height	New height of the widget.

Reimplemented in lvppImage.

◆ setText()

void lvppBase::setText ( const char * pText )

virtual

Set the Text for the primary text label. For a button, for instance, this is the text on top of the button.

Parameters

pText char pointer to the text

Reimplemented in lvppLabel.

◆ setTextAlign()

void lvppBase::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.

Parameters

align	This is an LVGL notion of alignment type. It is a very rich concept of alignment that does not simply use x/y screen coordinates but uses the x/y as an offset from some other 'anchor'. In concrete terms, this is one of LV_ALIGN_CENTER, LV_ALIGN_TOP_MID, LV_ALIGN_BOTTON_RIGHT, etc.
xoff	The x offset from the align point.
yoff	The y offset from the align point.

◆ setTextColor()

void lvppBase::setTextColor ( lv_color_t newColor )

Set the Text Color of the primary label object.

Parameters

newColor An lv_color_t for the desired color to use.

◆ whoAmI()

const char * lvppBase::whoAmI ( void )

Utility useful for dumping the friendly name and object type if needed.

Returns: const char* returned friendlyName(objectType)

Member Data Documentation

◆ adjLabel

lv_obj_t* lvppBase::adjLabel

protected

For items that have a label 'nearby' (adjacent label)

◆ bEventNamesInitComplete

bool lvppBase::bEventNamesInitComplete = false

staticprotected

Status of the event names table to avoid re-processing.

Uncommenting the definition of LOG_EVENTS will make for a noisy logging of all events. This can be useful if things feel upside down when you're adding features or something.

◆ cbOnClicked

std::function<void()> lvppBase::cbOnClicked =nullptr

protected

Start without a lambda callback.

◆ cbOnValueChanged

std::function<void()> lvppBase::cbOnValueChanged =nullptr

protected

Start without a lambda callback.

◆ friendlyName

std::string lvppBase::friendlyName

protected

◆ label

lv_obj_t* lvppBase::label

protected

Primary label.

◆ obj

lv_obj_t* lvppBase::obj

protected

The LVGL object that was created for this widget.

◆ objParent

lv_obj_t* lvppBase::objParent

protected

Any parent object (following same principle as LVGL here)

◆ objType

std::string lvppBase::objType

protected

◆ style_obj

lv_style_t lvppBase::style_obj

protected

Main style object - unsure if I'm handling all of the style bit correctly.

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

src/lvppBase.h
src/lvppBase.cpp

Public Member Functions

Static Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Static Protected Attributes

Detailed Description

Constructor & Destructor Documentation

◆ lvppBase()

◆ ~lvppBase()

Member Function Documentation

◆ align()

◆ baseEventHandler()

◆ createObj()

◆ eventHandler()

◆ getEventName()

◆ getFriendlyName()

◆ getLabelObj()

◆ getObj()

◆ getObjType()

◆ getText()

◆ initEventNames()

◆ internalOnClicked()

◆ internalOnValueChanged()

◆ isUnknownCode()

◆ lvCallback()

◆ onClicked()

◆ onValueChanged()

◆ setAdjBGColor()

◆ setAdjColorGradient()

◆ setAdjFont()

◆ setAdjJustificationAlignment()

◆ setAdjText()

◆ setAdjTextColor()

◆ setBGColor()

◆ setCallbackOnClicked()

◆ setCallbackOnValueChanged()

◆ setColorGradient()

◆ setFont()

◆ setFontSize()

◆ setFriendlyName()

◆ setLabelColorizationEnabled()

◆ setLabelJustificationAlignment()

◆ setNewParent()

◆ setObjType()

◆ setSize()

◆ setText()

◆ setTextAlign()

◆ setTextColor()

◆ whoAmI()

Member Data Documentation

◆ adjLabel

◆ bEventNamesInitComplete

◆ cbOnClicked

◆ cbOnValueChanged

◆ friendlyName

◆ label

◆ obj

◆ objParent

◆ objType

◆ style_obj