lvppBar Class Reference

Create a 'bar' widget from LVGL and allow range and value to be used. More...

#include <lvpp.h>

Inheritance diagram for lvppBar:

Collaboration diagram for lvppBar:

Public Member Functions
	lvppBar (const char *fName, lv_obj_t *parent=nullptr)
	Construct a new lvpp Bar object in the same way as most widget creations.
void	setRange (int16_t range_min, int16_t range_max)
	Set the Range of your new bar widget.
Public Member Functions inherited from lvppBaseWithValue
	lvppBaseWithValue (const char *fName, const char *oType)
	Construct a new lvpp object based on lvppBase which has an associated value.
virtual void	setValue (int16_t value, bool animate=true)
	Set the Value associated with the object. This is a pure virtual function and must be overridden and implemented by the derived class. When implementing your own derived class, be sure to not only set curValue = value, but also to send an event to trigger the update notification via: lv_event_send(obj, LV_EVENT_VALUE_CHANGED, NULL);
int16_t	getValue (void)
	Get the Value from the object.
uint16_t	getValuePercentage (void)
	Get the 'percentage' Value from the object. This is the percentage represented from min to max of the current value. It is bounded by min/max and returned as 0-100 as an integer value.
void	enableValueLabel (lv_coord_t xoff, lv_coord_t yoff, lv_align_t alignment=LV_ALIGN_CENTER)
	In the case where a label is desired to be shown for the value, enable it and align it here.
void	setValueLabelFormat (const char *fmt)
	Set the Value Label Format. This 'format' allows the label to be more than simply a number. The format needs a 'd' in there somewhere (ala printf style) but this allows you to have text before the number and even a '' after - for instance "Completeness: %d%%". When the value changes, the class will automatically apply this format with the new value.
void	setValueLabelColor (lv_color_t newColor)
	Set the Value Label's text Color.
void	setValueLabelBGColor (lv_color_t newColor)
	Set the Value Label's background Color.
void	setValueLabelColorGradient (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	setValueLabelJustificationAlignment (lv_text_align_t _align)
	Set the value Label's text alignment (left/right/center)
void	setValueLabelFont (const lv_font_t *pF)
	Set the Value Label Font.
void	setValueRange (int16_t _min, int16_t _max)
	Set the Value Range allowed. NOTE: This enforcement needs to happen in the derived setValue() function.
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.
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 Member Functions
int16_t	baseGetter ()
	Implementation of getting the value from the widget.
void	baseSetter (int16_t nVal, bool animate=true)
	Implementation which sets the current value of the widget itself. This function generally gets called by setValue()
Protected Member Functions inherited from lvppBaseWithValue
virtual int16_t	baseGetter ()=0
	Derived classes must implement this pure virtual by getting the current value from the widget itself. This function generally gets called by getValue()
virtual void	baseSetter (int16_t nVal, bool animate=true)=0
	Derived classes must implement this pure virtual which sets the current value of the widget itself. This function generally gets called by setValue()
void	internalOnValueChanged ()
	Internal handler for value change. Does the formatting as well.
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.

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.
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.
Protected Attributes inherited from lvppBaseWithValue
int16_t	curValue
	The value we're keeping and handling in this class.
lv_obj_t *	valueLabel
	The label that receives the formatted value if the label is enabled.
std::string	valueLabelFormat
	The format to use when the value changes.
int16_t	min
int16_t	max
	The allowable range of the value.
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.
Static Protected Attributes inherited from lvppBase
static bool	bEventNamesInitComplete = false
	Status of the event names table to avoid re-processing.

Detailed Description

Create a 'bar' widget from LVGL and allow range and value to be used.

This is based not on lvppBase but on lvppBaseWithValue as are a few other widget types.

Constructor & Destructor Documentation

lvppBar()

lvppBar::lvppBar	(	const char *	fName,
		lv_obj_t *	parent = nullptr
	)

Construct a new lvpp Bar object in the same way as most widget creations.

Parameters

fName	Internal object name. This is generally used in findObj() or lvppScreen
parent	If provided, the parent of the object. This is a real LVGL lv_obj_t pointer

Member Function Documentation

baseGetter()

int16_t lvppBar::baseGetter ( )

protectedvirtual

Implementation of getting the value from the widget.

Returns

int16_t Current value coming from the widget.

Implements lvppBaseWithValue.

baseSetter()

void lvppBar::baseSetter ( int16_t  nVal, bool  animate = true  )

protectedvirtual

Implementation which sets the current value of the widget itself. This function generally gets called by setValue()

Parameters

nVal	int16_t which is the value the widget shall be set to at this time.
animate	If widget supports it, animation to value.

Implements lvppBaseWithValue.

setRange()

void lvppBar::setRange	(	int16_t	range_min,
		int16_t	range_max
	)

Set the Range of your new bar widget.

Parameters

range_min	Minimum value for the bar
range_max	Maximum value for the bar

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

• src/lvpp.h
• src/lvppBar.cpp