Classes
struct	cvui_block_t

struct	cvui_context_t

struct	cvui_input_t

struct	cvui_label_t

struct	cvui_mouse_btn_t

struct	cvui_mouse_t

Functions
void	beginColumn (cv::Mat &theWhere, int theX, int theY, int theWidth=-1, int theHeight=-1, int thePadding=0)
	Start a new column. More...

void	beginColumn (int theWidth=-1, int theHeight=-1, int thePadding=0)
	Start a column. More...

void	beginRow (cv::Mat &theWhere, int theX, int theY, int theWidth=-1, int theHeight=-1, int thePadding=0)
	Start a new row. More...

void	beginRow (int theWidth=-1, int theHeight=-1, int thePadding=0)
	Start a row. More...

bool	button (const cv::String &theLabel)
	Display a button within a `begin()` and `end()` block. More...

bool	button (cv::Mat &theIdle, cv::Mat &theOver, cv::Mat &theDown)
	Display a button whose graphics are images (cv::Mat). More...

bool	button (cv::Mat &theWhere, int theX, int theY, const cv::String &theLabel)
	Display a button. More...

bool	button (cv::Mat &theWhere, int theX, int theY, cv::Mat &theIdle, cv::Mat &theOver, cv::Mat &theDown)
	Display a button whose graphics are images (cv::Mat). More...

bool	button (cv::Mat &theWhere, int theX, int theY, int theWidth, int theHeight, const cv::String &theLabel)
	Display a button. More...

bool	button (int theWidth, int theHeight, const cv::String &theLabel)
	Display a button within a `begin()` and `end()` block. More...

bool	checkbox (const cv::String &theLabel, bool *theState, unsigned int theColor=0xCECECE)
	Display a checkbox within a `begin()` and `end()` block. More...

bool	checkbox (cv::Mat &theWhere, int theX, int theY, const cv::String &theLabel, bool *theState, unsigned int theColor=0xCECECE)
	Display a checkbox. More...

void	context (const cv::String &theWindowName)
	Inform cvui that all subsequent component calls belong to a window in particular. More...

double	counter (cv::Mat &theWhere, int theX, int theY, double theValue, double theStep=0.5, const char theFormat="%.2f")
	Display a counter for float values that the user can increase/descrease by clicking the up and down arrows. More...

int	counter (cv::Mat &theWhere, int theX, int theY, int theValue, int theStep=1, const char theFormat="%d")
	Display a counter for integer values that the user can increase/descrease by clicking the up and down arrows. More...

double	counter (double theValue, double theStep=0.5, const char theFormat="%.2f")
	Display a counter for float values that the user can increase/descrease by clicking the up and down arrows. More...

int	counter (int theValue, int theStep=1, const char theFormat="%d")
	Display a counter for integer values that the user can increase/descrease by clicking the up and down arrows. More...

void	endColumn ()
	End a column. More...

void	endRow ()
	Ends a row. More...

void	handleMouse (int theEvent, int theX, int theY, int theFlags, void *theData)

bool	headless ()
	Inform if cvui is running in headless more. More...

void	headless (bool theValue)
	Enable/disable headless more. More...

int	iarea (int theX, int theY, int theWidth, int theHeight)
	Create an interaction area that reports activity with the mouse cursor. More...

void	image (cv::Mat &theImage)
	Display an image (cv::Mat) within a `begin()` and `end()` block. More...

void	image (cv::Mat &theWhere, int theX, int theY, cv::Mat &theImage)
	Display an image (cv::Mat). More...

void	imshow (const cv::String &theWindowName, cv::InputArray theFrame)
	Display an image in the specified window and update the internal structures of cvui. More...

void	init (const cv::String &theWindowName, int theDelayWaitKey=-1, bool theCreateNamedWindow=true, bool theHeadlessMode=false)
	Initializes cvui. More...

void	init (const cv::String theWindowNames[], size_t theHowManyWindows, int theDelayWaitKey=-1, bool theCreateNamedWindows=true, bool theHeadlessMode=false)
	Initialize cvui using a list of names of windows where components will be added. More...

int	input (cv::Mat &theWhere, int theX, int theY, int theWidth, const cv::String theName, cv::String &theValue, double theFontScale=0.5)
	Display an inputtext. More...

int	lastKeyPressed ()
	Return the last key that was pressed. More...

bool	mouse (const cv::String &theWindowName, int theButton, int theQuery)
	Query the mouse for events in a particular button in a particular window. More...

bool	mouse (const cv::String &theWindowName, int theQuery)
	Query the mouse for events in a particular window. More...

cv::Point	mouse (const cv::String &theWindowName="")
	Return the last position of the mouse. More...

bool	mouse (int theButton, int theQuery)
	Query the mouse for events in a particular button. More...

bool	mouse (int theQuery)
	Query the mouse for events, e.g. More...

void	printf (const char *theFmt,...)
	Display a piece of text that can be formated using `stdio's printf()` style. More...

void	printf (cv::Mat &theWhere, int theX, int theY, const char *theFmt,...)
	Display a piece of text that can be formated using `stdio's printf()` style. More...

void	printf (cv::Mat &theWhere, int theX, int theY, double theFontScale, unsigned int theColor, const char *theFmt,...)
	Display a piece of text that can be formated using `stdio's printf()` style. More...

void	printf (double theFontScale, unsigned int theColor, const char *theFmt,...)
	Display a piece of text within a `begin()` and `end()` block. More...

void	rect (cv::Mat &theWhere, int theX, int theY, int theWidth, int theHeight, unsigned int theBorderColor, unsigned int theFillingColor=0xff000000)
	Display a filled rectangle. More...

void	rect (int theWidth, int theHeight, unsigned int theBorderColor, unsigned int theFillingColor=0xff000000)
	Display a rectangle within a `begin()` and `end()` block. More...

void	space (int theValue=5)
	Add an arbitrary amount of space between components within a `begin()` and `end()` block. More...

void	sparkline (cv::Mat &theWhere, std::vector< double > &theValues, int theX, int theY, int theWidth, int theHeight, unsigned int theColor=0x00FF00)
	Display the values of a vector as a sparkline. More...

void	sparkline (std::vector< double > &theValues, int theWidth, int theHeight, unsigned int theColor=0x00FF00)
	Display the values of a vector as a sparkline within a `begin()` and `end()` block. More...

void	text (const cv::String &theText, double theFontScale=0.4, unsigned int theColor=0xCECECE)
	Display a piece of text within a `begin()` and `end()` block. More...

void	text (cv::Mat &theWhere, int theX, int theY, const cv::String &theText, double theFontScale=0.4, unsigned int theColor=0xCECECE)
	Display a piece of text. More...

template<typename num_type >
bool	trackbar (cv::Mat &theWhere, int theX, int theY, int theWidth, num_type theValue, num_type theMin, num_type theMax, int theSegments, const char theLabelFormat, unsigned int theOptions, num_type theDiscreteStep)

template<typename T >
bool	trackbar (cv::Mat &theWhere, int theX, int theY, int theWidth, T theValue, T theMin, T theMax, int theSegments=1, const char theLabelFormat="%.1Lf", unsigned int theOptions=0, T theDiscreteStep=1)
	Display a trackbar for numeric values that the user can increase/decrease by clicking and/or dragging the marker right or left. More...

template<typename num_type >
bool	trackbar (int theWidth, num_type theValue, num_type theMin, num_type theMax, int theSegments, const char theLabelFormat, unsigned int theOptions, num_type theDiscreteStep)

template<typename T >
bool	trackbar (int theWidth, T theValue, T theMin, T theMax, int theSegments=1, const char theLabelFormat="%.1Lf", unsigned int theOptions=0, T theDiscreteStep=1)
	Display a trackbar for numeric values that the user can increase/decrease by clicking and/or dragging the marker right or left. More...

void	update (const cv::String &theWindowName="")
	Update the library internal things. More...

void	watch (const cv::String &theWindowName, bool theCreateNamedWindow=true)
	Track UI interactions of a particular window. More...

void	window (cv::Mat &theWhere, int theX, int theY, int theWidth, int theHeight, const cv::String &theTitle)
	Display a window (a block with a title and a body). More...

void	window (int theWidth, int theHeight, const cv::String &theTitle)
	Display a window (a block with a title and a body) within a `begin()` and `end()` block. More...

Variables
const int	CLICK = 3

const int	COLUMN = 1

const int	DOWN = 2

const unsigned int	INTPUT_CURSOR_BLINK_SLOWNESS = 10

const int	IS_DOWN = 7

const unsigned int	KEY_ARROW_DOWN = 2621440

const unsigned int	KEY_ARROW_LEFT = 2424832

const unsigned int	KEY_ARROW_RIGHT = 2555904

const unsigned int	KEY_ARROW_UP = 2490368

const unsigned int	KEY_BACKSPACE = 8

const unsigned int	KEY_DELETE = 3014656

const unsigned int	KEY_END = 2293760

const unsigned int	KEY_ENTER = 13

const unsigned int	KEY_HOME = 2359296

const unsigned int	KEY_NONE = -1

const unsigned int	KEY_TAB = 9

const int	LEFT_BUTTON = 0

const int	MIDDLE_BUTTON = 1

const int	OUT = 5

const int	OVER = 4

const int	RIGHT_BUTTON = 2

const int	ROW = 0

const unsigned int	TRACKBAR_DISCRETE = 4

const unsigned int	TRACKBAR_HIDE_LABELS = 32

const unsigned int	TRACKBAR_HIDE_MIN_MAX_LABELS = 8

const unsigned int	TRACKBAR_HIDE_SEGMENT_LABELS = 1

const unsigned int	TRACKBAR_HIDE_STEP_SCALE = 2

const unsigned int	TRACKBAR_HIDE_VALUE_LABEL = 16

const int	UP = 6

Function Documentation

◆ beginColumn() [1/2]

void cvui::beginColumn	(	cv::Mat &	theWhere,
		int	theX,
		int	theY,
		int	theWidth = `-1`,
		int	theHeight = `-1`,
		int	thePadding = `0`
	)

Start a new column.

One of the most annoying tasks when building UI is to calculate where each component should be placed on the screen. cvui has a set of methods that abstract the process of positioning components, so you don't have to think about assigning a X and Y coordinate. Instead you just add components and cvui will place them as you go.

You use beginColumn() to start a group of elements. After beginColumn() has been called, all subsequent component calls don't have to specify the frame where the component should be rendered nor its position. The position of the component will be automatically calculated by cvui based on the components within the group. All components are placed below each other, from the top of the screen towards the bottom.

E.g.

beginColumn(frame, x, y, width, height);
 text("test");
 button("btn");
endColumn();

Rows and columns can be nested, so you can create columns/rows within columns/rows as much as you want. It's important to notice that any component within beginColumn() and endColumn() do not specify the position where the component is rendered, which is also true for beginColumn(). As a consequence, be sure you are calling beginColumn(width, height) when the call is nested instead of beginColumn(x, y, width, height), otherwise cvui will throw an error.

E.g.

beginColumn(frame, x, y, width, height);
 text("test");
 button("btn");
 
 beginRow();      // no frame nor x,y parameters here!
  text("column1");
  text("column2");
 endRow();
endColumn();

Don't forget to call endColumn() to finish the column, otherwise cvui will throw an error.

Parameters

theWhere	image/frame where the components within this block should be rendered.
theX	position X where the row should be placed.
theY	position Y where the row should be placed.
theWidth	width of the column. If a negative value is specified, the width of the column will be automatically calculated based on the content of the block.
theHeight	height of the column. If a negative value is specified, the height of the column will be automatically calculated based on the content of the block.
thePadding	space, in pixels, among the components of the block.

See also: beginRow(); endColumn(); endRow()

Referenced by EnhancedWindow::begin(), and main().

◆ beginColumn() [2/2]

void cvui::beginColumn	(	int	theWidth = `-1`,
		int	theHeight = `-1`,
		int	thePadding = `0`
	)

Start a column.

This function behaves in the same way as beginColumn(frame, x, y, width, height), however it is suposed to be used within begin*()/end*() blocks since they require components not to inform frame nor x,y coordinates.

IMPORTANT: this function can only be used within a begin*()/end*() block, otherwise it does nothing.

Parameters

theWidth	width of the column. If a negative value is specified, the width of the column will be automatically calculated based on the content of the block.
theHeight	height of the column. If a negative value is specified, the height of the column will be automatically calculated based on the content of the block.
thePadding	space, in pixels, among the components of the block.

See also: beginColumn(); endRow(); endColumn()

Referenced by EnhancedWindow.EnhancedWindow::begin(), multiple-windows-complex::main(), nested-rows-columns::main(), on-image::main(), trackbar-complex::main(), row-column::main(), and multiple-windows-complex-dynamic::main().

◆ beginRow() [1/2]

void cvui::beginRow	(	cv::Mat &	theWhere,
		int	theX,
		int	theY,
		int	theWidth = `-1`,
		int	theHeight = `-1`,
		int	thePadding = `0`
	)

Start a new row.

One of the most annoying tasks when building UI is to calculate where each component should be placed on the screen. cvui has a set of methods that abstract the process of positioning components, so you don't have to think about assigning a X and Y coordinate. Instead you just add components and cvui will place them as you go.

You use beginRow() to start a group of elements. After beginRow() has been called, all subsequent component calls don't have to specify the frame where the component should be rendered nor its position. The position of the component will be automatically calculated by cvui based on the components within the group. All components are placed side by side, from left to right.

E.g.

beginRow(frame, x, y, width, height);
 text("test");
 button("btn");
endRow();

Rows and columns can be nested, so you can create columns/rows within columns/rows as much as you want. It's important to notice that any component within beginRow() and endRow() do not specify the position where the component is rendered, which is also true for beginRow(). As a consequence, be sure you are calling beginRow(width, height) when the call is nested instead of beginRow(x, y, width, height), otherwise cvui will throw an error.

E.g.

beginRow(frame, x, y, width, height);
 text("test");
 button("btn");
 
 beginColumn();      // no frame nor x,y parameters here!
  text("column1");
  text("column2");
 endColumn();
endRow();

Don't forget to call endRow() to finish the row, otherwise cvui will throw an error.

Parameters

theWhere	image/frame where the components within this block should be rendered.
theX	position X where the row should be placed.
theY	position Y where the row should be placed.
theWidth	width of the row. If a negative value is specified, the width of the row will be automatically calculated based on the content of the block.
theHeight	height of the row. If a negative value is specified, the height of the row will be automatically calculated based on the content of the block.
thePadding	space, in pixels, among the components of the block.

See also: beginColumn(); endRow(); endColumn()

Referenced by EnhancedWindow::begin(), and main().

◆ beginRow() [2/2]

void cvui::beginRow	(	int	theWidth = `-1`,
		int	theHeight = `-1`,
		int	thePadding = `0`
	)

Start a row.

This function behaves in the same way as beginRow(frame, x, y, width, height), however it is suposed to be used within begin*()/end*() blocks since they require components not to inform frame nor x,y coordinates.

IMPORTANT: this function can only be used within a begin*()/end*() block, otherwise it does nothing.

Parameters

theWidth	width of the row. If a negative value is specified, the width of the row will be automatically calculated based on the content of the block.
theHeight	height of the row. If a negative value is specified, the height of the row will be automatically calculated based on the content of the block.
thePadding	space, in pixels, among the components of the block.

See also: beginColumn(); endRow(); endColumn()

Referenced by EnhancedWindow.EnhancedWindow::begin(), multiple-windows-complex::main(), nested-rows-columns::main(), trackbar-sparkline::main(), and row-column::main().

◆ button() [1/6]

bool cvui::button ( const cv::String & theLabel )

Display a button within a begin*() and end*() block.

The size of the button will be automatically adjusted to properly house the label content.

IMPORTANT: this function can only be used within a begin*()/end*() block, otherwise it does nothing.

Parameters

theLabel text displayed inside the button. You can set shortcuts by pre-pending them with "&"

Returns: true everytime the user clicks the button.

See also: beginColumn(); beginRow(); endRow(); endColumn()

◆ button() [2/6]

bool cvui::button	(	cv::Mat &	theIdle,
		cv::Mat &	theOver,
		cv::Mat &	theDown
	)

Display a button whose graphics are images (cv::Mat).

IMPORTANT: this function can only be used within a begin*()/end*() block, otherwise it does nothing.

The button accepts three images to describe its states, which are idle (no mouse interaction), over (mouse is over the button) and down (mouse clicked the button). The button size will be defined by the width and height of the images.

Parameters

theIdle	image that will be rendered when the button is not interacting with the mouse cursor.
theOver	image that will be rendered when the mouse cursor is over the button.
theDown	image that will be rendered when the mouse cursor clicked the button (or is clicking).

Returns: true everytime the user clicks the button.

See also: button(); image(); iarea(); beginColumn(); beginRow(); endRow(); endColumn()

Referenced by EnhancedWindow.EnhancedWindow::begin(), multiple-windows::compact(), input-change-counter::main(), input-react-key::main(), input-sizes::main(), image-button::main(), main-app::main(), input-detect-key::main(), input-multiple::main(), hello-world::main(), input::main(), multiple-windows-complex::main(), nested-rows-columns::main(), button-shortcut::main(), trackbar-complex::main(), on-image::main(), trackbar-sparkline::main(), row-column::main(), multiple-windows-complex-dynamic::main(), and multiple-windows::window().

◆ button() [3/6]

bool cvui::button	(	cv::Mat &	theWhere,
		int	theX,
		int	theY,
		const cv::String &	theLabel
	)

Display a button.

The size of the button will be automatically adjusted to properly house the label content.

Parameters

theWhere	image/frame where the component should be rendered.
theX	position X where the component should be placed.
theY	position Y where the component should be placed.
theLabel	text displayed inside the button.

Returns: true everytime the user clicks the button.

Referenced by EnhancedWindow::begin(), compact(), main(), and window().

◆ button() [4/6]

bool cvui::button	(	cv::Mat &	theWhere,
		int	theX,
		int	theY,
		cv::Mat &	theIdle,
		cv::Mat &	theOver,
		cv::Mat &	theDown
	)

Display a button whose graphics are images (cv::Mat).

The button accepts three images to describe its states, which are idle (no mouse interaction), over (mouse is over the button) and down (mouse clicked the button). The button size will be defined by the width and height of the images.

Parameters

theWhere	image/frame where the component should be rendered.
theX	position X where the component should be placed.
theY	position Y where the component should be placed.
theIdle	an image that will be rendered when the button is not interacting with the mouse cursor.
theOver	an image that will be rendered when the mouse cursor is over the button.
theDown	an image that will be rendered when the mouse cursor clicked the button (or is clicking).

Returns: true everytime the user clicks the button.

See also: button(); image(); iarea()

◆ button() [5/6]

bool cvui::button	(	cv::Mat &	theWhere,
		int	theX,
		int	theY,
		int	theWidth,
		int	theHeight,
		const cv::String &	theLabel
	)

Display a button.

The button size will be defined by the width and height parameters, no matter the content of the label.

Parameters

theWhere	image/frame where the component should be rendered.
theX	position X where the component should be placed.
theY	position Y where the component should be placed.
theWidth	width of the button.
theHeight	height of the button.
theLabel	text displayed inside the button.

Returns: true everytime the user clicks the button.

◆ button() [6/6]

bool cvui::button	(	int	theWidth,
		int	theHeight,
		const cv::String &	theLabel
	)

Display a button within a begin*() and end*() block.

The button size will be defined by the width and height parameters, no matter the content of the label.

IMPORTANT: this function can only be used within a begin*()/end*() block, otherwise it does nothing.

Parameters

theWidth	width of the button.
theHeight	height of the button.
theLabel	text displayed inside the button. You can set shortcuts by pre-pending them with "&"

Returns: true everytime the user clicks the button.

See also: beginColumn(); beginRow(); endRow(); endColumn()

◆ checkbox() [1/2]

bool cvui::checkbox	(	const cv::String &	theLabel,
		bool *	theState,
		unsigned int	theColor = `0xCECECE`
	)

Display a checkbox within a begin*() and end*() block.

You can use the state parameter to monitor if the checkbox is checked or not.

IMPORTANT: this function can only be used within a begin*()/end*() block, otherwise it does nothing.

Parameters

theLabel	text displayed besides the clickable checkbox square.
theState	describes the current state of the checkbox: `true` means the checkbox is checked.
theColor	color of the label in the format `0xRRGGBB`, e.g. `0xff0000` for red.

Returns: a boolean value that indicates the current state of the checkbox, true if it is checked.

See also: beginColumn(); beginRow(); endRow(); endColumn()

Referenced by headless::main(), main-app::main(), canny::main(), multiple-windows-complex::main(), ui-enhanced-canny::main(), row-column::main(), and Class1.Class1::renderInfo().

◆ checkbox() [2/2]

bool cvui::checkbox	(	cv::Mat &	theWhere,
		int	theX,
		int	theY,
		const cv::String &	theLabel,
		bool *	theState,
		unsigned int	theColor = `0xCECECE`
	)

Display a checkbox.

You can use the state parameter to monitor if the checkbox is checked or not.

Parameters

theWhere	image/frame where the component should be rendered.
theX	position X where the component should be placed.
theY	position Y where the component should be placed.
theLabel	text displayed besides the clickable checkbox square.
theState	describes the current state of the checkbox: `true` means the checkbox is checked.
theColor	color of the label in the format `0xRRGGBB`, e.g. `0xff0000` for red.

Returns: a boolean value that indicates the current state of the checkbox, true if it is checked.

Referenced by main(), and Class1::renderInfo().

◆ context()

void cvui::context ( const cv::String & theWindowName )

Inform cvui that all subsequent component calls belong to a window in particular.

When using cvui with multiple OpenCV windows, you must call cvui component calls between cvui::contex(NAME) and cvui::update(NAME), where NAME is the name of the window. That way, cvui knows which window you are using (NAME in this case), so it can track mouse events, for instance.

E.g.

// Code for window "window1".
cvui::context("window1");
cvui::text(frame, ...);
cvui::button(frame, ...);
cvui::update("window1");
 
 
// somewhere else, code for "window2"
cvui::context("window2");
cvui::printf(frame, ...);
cvui::printf(frame, ...);
cvui::update("window2");
 
// Show everything in a window
cv::imshow(frame);

Pay attention to the pair cvui::context(NAME) and cvui::update(NAME), which encloses the component calls for that window. You need such pair for each window of your application.

After calling cvui::update(), you can show the result in a window using cv::imshow(). If you want to save some typing, you can use cvui::imshow(), which calls cvui::update() for you and then shows the frame in a window.

E.g.:

// Code for window "window1".
cvui::context("window1");
cvui::text(frame, ...);
cvui::button(frame, ...);
cvui::imshow("window1");
 
// somewhere else, code for "window2"
cvui::context("window2");
cvui::printf(frame, ...);
cvui::printf(frame, ...);
cvui::imshow("window2");

In that case, you don't have to bother calling cvui::update() yourself, since cvui::imshow() will do it for you.

Parameters

theWindowName name of the window that will receive components from all subsequent cvui calls.

See also: init(); watch()

Referenced by multiple-windows::compact(), compact(), main(), multiple-windows-complex::main(), multiple-windows-complex-mouse::main(), multiple-windows-complex-dynamic::main(), multiple-windows::window(), and window().

◆ counter() [1/4]

double cvui::counter	(	cv::Mat &	theWhere,
		int	theX,
		int	theY,
		double *	theValue,
		double	theStep = `0.5`,
		const char *	theFormat = `"%.2f"`
	)

Display a counter for float values that the user can increase/descrease by clicking the up and down arrows.

Parameters

theWhere	image/frame where the component should be rendered.
theX	position X where the component should be placed.
theY	position Y where the component should be placed.
theValue	the current value of the counter.
theStep	the amount that should be increased/decreased when the user interacts with the counter buttons
theFormat	how the value of the counter should be presented, as it was printed by `stdio's printf()`. E.g. `"%f"` means the value will be displayed as a regular float, `"%.2f"` float with two digits after the point, etc.

Returns: a float that corresponds to the current value of the counter.

◆ counter() [2/4]

int cvui::counter	(	cv::Mat &	theWhere,
		int	theX,
		int	theY,
		int *	theValue,
		int	theStep = `1`,
		const char *	theFormat = `"%d"`
	)

Display a counter for integer values that the user can increase/descrease by clicking the up and down arrows.

Parameters

theWhere	image/frame where the component should be rendered.
theX	position X where the component should be placed.
theY	position Y where the component should be placed.
theValue	the current value of the counter.
theStep	the amount that should be increased/decreased when the user interacts with the counter buttons
theFormat	how the value of the counter should be presented, as it was printed by `stdio's printf()`. E.g. `"%d"` means the value will be displayed as an integer, `"%0d"` integer with one leading zero, etc.

Returns: integer that corresponds to the current value of the counter.

Referenced by main().

◆ counter() [3/4]

double cvui::counter	(	double *	theValue,
		double	theStep = `0.5`,
		const char *	theFormat = `"%.2f"`
	)

Display a counter for float values that the user can increase/descrease by clicking the up and down arrows.

IMPORTANT: this function can only be used within a begin*()/end*() block, otherwise it does nothing.

Parameters

theValue	the current value of the counter.
theStep	the amount that should be increased/decreased when the user interacts with the counter buttons.
theFormat	how the value of the counter should be presented, as it was printed by `stdio's printf()`. E.g. `"%d"` means the value will be displayed as an integer, `"%0d"` integer with one leading zero, etc.

Returns: an float that corresponds to the current value of the counter.

See also: printf(); beginColumn(); beginRow(); endRow(); endColumn()

Referenced by input-change-counter::main(), main-app::main(), multiple-windows-complex::main(), and row-column::main().

◆ counter() [4/4]

int cvui::counter	(	int *	theValue,
		int	theStep = `1`,
		const char *	theFormat = `"%d"`
	)

Display a counter for integer values that the user can increase/descrease by clicking the up and down arrows.

IMPORTANT: this function can only be used within a begin*()/end*() block, otherwise it does nothing.

Parameters

theValue	the current value of the counter.
theStep	the amount that should be increased/decreased when the user interacts with the counter buttons.
theFormat	how the value of the counter should be presented, as it was printed by `stdio's printf()`. E.g. `"%d"` means the value will be displayed as an integer, `"%0d"` integer with one leading zero, etc.

Returns: integer that corresponds to the current value of the counter.

See also: printf(); beginColumn(); beginRow(); endRow(); endColumn()

◆ endColumn()

void cvui::endColumn ( )

End a column.

You must call this function only if you have previously called its counter part, i.e. beginColumn().

See also: beginColumn(); beginRow(); endRow()

Referenced by EnhancedWindow.EnhancedWindow::end(), EnhancedWindow::end(), multiple-windows-complex::main(), main(), nested-rows-columns::main(), trackbar-complex::main(), on-image::main(), row-column::main(), and multiple-windows-complex-dynamic::main().

◆ endRow()

void cvui::endRow ( )

Ends a row.

You must call this function only if you have previously called its counter part, the beginRow() function.

See also: beginRow(); beginColumn(); endColumn()

Referenced by EnhancedWindow.EnhancedWindow::end(), EnhancedWindow::end(), multiple-windows-complex::main(), main(), nested-rows-columns::main(), trackbar-sparkline::main(), and row-column::main().

◆ handleMouse()

void cvui::handleMouse	(	int	theEvent,
		int	theX,
		int	theY,
		int	theFlags,
		void *	theData
	)

◆ headless() [1/2]

bool cvui::headless ( )

Inform if cvui is running in headless more.

Returns: true if running in headless mode, or false otherwise.

See also: init()

◆ headless() [2/2]

void cvui::headless ( bool theValue )

Enable/disable headless more.

When running in headless mode, cvui will not render anything to the screen and it will not process interactions such as mouse clicks. This mode is useful to test apps in CI/CD.

Parameters

theValue true if cvui should run in headless more, false otherwise.

See also: init()

◆ iarea()

int cvui::iarea	(	int	theX,
		int	theY,
		int	theWidth,
		int	theHeight
	)

Create an interaction area that reports activity with the mouse cursor.

The tracked interactions are returned by the function and they are:

OUT when the cursor is not over the iarea. OVER when the cursor is over the iarea. DOWN when the cursor is pressed over the iarea, but not released yet. CLICK when the cursor clicked (pressed and released) within the iarea.

This function creates no visual output on the screen. It is intended to be used as an auxiliary tool to create interactions.

Parameters

theX	position X where the interactive area should be placed.
theY	position Y where the interactive area should be placed.
theWidth	width of the interactive area.
theHeight	height of the interactive area.

Returns: integer value representing the current state of interaction with the mouse cursor. It can be OUT (cursor is not over the area), OVER (cursor is over the area), DOWN (cursor is pressed over the area, but not released yet) and CLICK (cursor clicked, i.e. pressed and released, within the area).

See also: button(); image()

Referenced by interaction-area::main(), and main().

◆ image() [1/2]

void cvui::image ( cv::Mat & theImage )

Display an image (cv::Mat) within a begin*() and end*() block.

IMPORTANT: this function can only be used within a begin*()/end*() block, otherwise it does nothing.

Parameters

theImage image to be rendered in the specified destination.

See also: button(); iarea(); beginColumn(); beginRow(); endRow(); endColumn()

Referenced by multiple-windows-complex::main(), and row-column::main().

◆ image() [2/2]

void cvui::image	(	cv::Mat &	theWhere,
		int	theX,
		int	theY,
		cv::Mat &	theImage
	)

Display an image (cv::Mat).

Parameters

theWhere	image/frame where the provded image should be rendered.
theX	position X where the image should be placed.
theY	position Y where the image should be placed.
theImage	image to be rendered in the specified destination.

See also: button(); iarea()

Referenced by main().

◆ imshow()

void cvui::imshow	(	const cv::String &	theWindowName,
		cv::InputArray	theFrame
	)

Display an image in the specified window and update the internal structures of cvui.

This function can be used as a replacement for cv::imshow(). If you want to use cv::imshow() instead ofcvui::imshow(), you must ensure you callcvui::update() after* all component calls and *before*cv::imshow()`, so cvui can update its internal structures.

In general, it is easier to call cvui::imshow() alone instead of calling ‘cvui::update()’ immediately followed by cv::imshow().

Parameters

theWindowName	name of the window that will be shown.
theFrame	image, i.e. `cv::Mat`, to be shown in the window.

See also: update(); context(); watch()

Referenced by multiple-windows::compact(), compact(), headless::main(), hello-world::main(), mouse::main(), main(), multiple-windows-complex-mouse::main(), ui-enhanced-window-component::main(), multiple-windows::window(), and window().

◆ init() [1/2]

void cvui::init	(	const cv::String &	theWindowName,
		int	theDelayWaitKey = `-1`,
		bool	theCreateNamedWindow = `true`,
		bool	theHeadlessMode = `false`
	)

Initializes cvui.

You must provide the name of the window where components will be added. It is also possible to tell cvui to handle OpenCV's event queue automatically (by informing a value greater than zero in the theDelayWaitKey parameter of the function). In that case, cvui will automatically call cv::waitKey() within cvui::update(), so you don't have to worry about it. The value passed to theDelayWaitKey will be used as the delay for cv::waitKey().

Parameters

theWindowName	name of the window where the components will be added.
theDelayWaitKey	delay value passed to `cv::waitKey()`. If a negative value is informed (default is `-1`), cvui will not automatically call `cv::waitKey()` within `cvui::update()`, which will disable keyboard shortcuts for all components. If you want to enable keyboard shortcut for components (e.g. using & in a button label), you must specify a positive value for this param.
theCreateNamedWindow	if an OpenCV window named `theWindowName` should be created during the initialization. Windows are created using `cv::namedWindow()`. If this parameter is `false`, ensure you call `cv::namedWindow(WINDOW_NAME)` before initializing cvui, otherwise it will not be able to track UI interactions.
theHeadlessMode	if cvui should run in headless more (no rendering or processing of interactions, useful for CI testing).

See also: watch(); context()

Referenced by main().

◆ init() [2/2]

void cvui::init	(	const cv::String	theWindowNames[],
		size_t	theHowManyWindows,
		int	theDelayWaitKey = `-1`,
		bool	theCreateNamedWindows = `true`,
		bool	theHeadlessMode = `false`
	)

Initialize cvui using a list of names of windows where components will be added.

It is also possible to tell cvui to handle OpenCV's event queue automatically (by informing a value greater than zero in the theDelayWaitKey parameter of the function). In that case, cvui will automatically call cv::waitKey() within cvui::update(), so you don't have to worry about it. The value passed to theDelayWaitKey will be used as the delay for cv::waitKey().

Parameters

theWindowNames	array containing the name of the windows where components will be added. Those windows will be automatically if `theCreateNamedWindows` is `true`.
theHowManyWindows	how many window names exist in the `theWindowNames` array.
theDelayWaitKey	delay value passed to `cv::waitKey()`. If a negative value is informed (default is `-1`), cvui will not automatically call `cv::waitKey()` within `cvui::update()`, which will disable keyboard shortcuts for all components. If you want to enable keyboard shortcut for components (e.g. using & in a button label), you must specify a positive value for this param.
theCreateNamedWindows	if OpenCV windows named according to `theWindowNames` should be created during the initialization. Windows are created using `cv::namedWindow()`. If this parameter is `false`, ensure you call `cv::namedWindow(WINDOW_NAME)` for all windows before initializing cvui, otherwise it will not be able to track UI interactions.
theHeadlessMode	if cvui should run in headless more (no rendering or processing of interactions, useful for CI testing).

See also: watch(); context()

Referenced by input-change-counter::main(), input-detect-key::main(), input-multiple::main(), input-react-key::main(), input-sizes::main(), headless::main(), image-button::main(), main-app::main(), mouse::main(), canny::main(), hello-world::main(), mouse-complex::main(), multiple-windows-complex::main(), input::main(), interaction-area::main(), multiple-windows-complex-mouse::main(), nested-rows-columns::main(), mouse-complex-buttons::main(), multiple-files::main(), button-shortcut::main(), trackbar-sparkline::main(), trackbar::main(), on-image::main(), trackbar-complex::main(), ui-enhanced-window-component::main(), ui-enhanced-canny::main(), row-column::main(), sparkline::main(), multiple-windows-complex-dynamic::main(), complex-layout::main(), and multiple-windows::main().

◆ input()

int cvui::input	(	cv::Mat &	theWhere,
		int	theX,
		int	theY,
		int	theWidth,
		const cv::String	theName,
		cv::String &	theValue,
		double	theFontScale = `0.5`
	)

Display an inputtext.

Parameters

theWhere	image/frame where the provided input should be rendered.
theX	position X where the input should be placed.
theY	position Y where the input should be placed.
theWidth	size, in pixels, of the input.
theName	unique name of the input. It will be used to control focus.
theValue	content of the input.
theFontScale	size of the text.

See also: button(); counter()

Referenced by input-change-counter::main(), input-detect-key::main(), input-react-key::main(), input-sizes::main(), input-multiple::main(), input::main(), and main().

◆ lastKeyPressed()

int cvui::lastKeyPressed ( )

Return the last key that was pressed.

This function will only work if a value greater than zero was passed to cvui::init() as the delay waitkey parameter.

See also: init()

◆ mouse() [1/5]

bool cvui::mouse	(	const cv::String &	theWindowName,
		int	theButton,
		int	theQuery
	)

Query the mouse for events in a particular button in a particular window.

This function behave exactly like cvui::mouse(int theButton, int theQuery), with the difference that queries are targeted at a particular mouse button in a particular window instead.

Parameters

theWindowName	name of the window that will be queried.
theButton	integer describing the mouse button to be queried. Possible values are `cvui::LEFT_BUTTON`, `cvui::MIDDLE_BUTTON` and `cvui::LEFT_BUTTON`.
theQuery	integer describing the intended mouse query. Available queries are `cvui::DOWN`, `cvui::UP`, `cvui::CLICK`, and `cvui::IS_DOWN`.

Referenced by EnhancedWindow.EnhancedWindow::begin(), mouse::main(), interaction-area::main(), mouse-complex::main(), multiple-windows-complex-mouse::main(), and mouse-complex-buttons::main().

◆ mouse() [2/5]

bool cvui::mouse	(	const cv::String &	theWindowName,
		int	theQuery
	)

Query the mouse for events in a particular window.

This function behave exactly like cvui::mouse(int theQuery) with the difference that queries are targeted at a particular window.

Parameters

theWindowName	name of the window that will be queried.
theQuery	integer describing the intended mouse query. Available queries are `cvui::DOWN`, `cvui::UP`, `cvui::CLICK`, and `cvui::IS_DOWN`.

See also: mouse(const cv::String&); mouse(const cv::String&, int, int); mouse(int, int); mouse(int)

◆ mouse() [3/5]

cv::Point cvui::mouse ( const cv::String & theWindowName = "" )

Return the last position of the mouse.

Parameters

theWindowName name of the window whose mouse cursor will be used. If nothing is informed (default), the function will return the position of the mouse cursor for the default window (the one informed in cvui::init()).

Returns: a point containing the position of the mouse cursor in the speficied window.

Referenced by EnhancedWindow::begin(), and main().

◆ mouse() [4/5]

bool cvui::mouse	(	int	theButton,
		int	theQuery
	)

Query the mouse for events in a particular button.

This function behave exactly like cvui::mouse(int theQuery), with the difference that queries are targeted at a particular mouse button instead.

Parameters

theButton	integer describing the mouse button to be queried. Possible values are `cvui::LEFT_BUTTON`, `cvui::MIDDLE_BUTTON` and `cvui::LEFT_BUTTON`.
theQuery	integer describing the intended mouse query. Available queries are `cvui::DOWN`, `cvui::UP`, `cvui::CLICK`, and `cvui::IS_DOWN`.

See also: mouse(const cv::String&); mouse(const cv::String&, int, int); mouse(int)

◆ mouse() [5/5]

bool cvui::mouse ( int theQuery )

Query the mouse for events, e.g.

"is any button down now?". Available queries are:

cvui::DOWN: any mouse button was pressed. cvui::mouse() returns true for a single frame only. cvui::UP: any mouse button was released. cvui::mouse() returns true for a single frame only. cvui::CLICK: any mouse button was clicked (went down then up, no matter the amount of frames in between). cvui::mouse() returns true for a single frame only. cvui::IS_DOWN: any mouse button is currently pressed. cvui::mouse() returns true for as long as the button is down/pressed.

It is easier to think of this function as the answer to a questions. For instance, asking if any mouse button went down:

if (cvui::mouse(cvui::DOWN)) {
  // Any mouse button just went down.
}

The window whose mouse will be queried depends on the context. If cvui::mouse(query) is being called after cvui::context(), the window informed in the context will be queried. If no context is available, the default window (informed in cvui::init()) will be used.

Parameters

theQuery integer describing the intended mouse query. Available queries are cvui::DOWN, cvui::UP, cvui::CLICK, and cvui::IS_DOWN.

See also: mouse(const cv::String&); mouse(const cv::String&, int); mouse(const cv::String&, int, int); mouse(int, int)

◆ printf() [1/4]

void cvui::printf	(	const char *	theFmt,
			...
	)

Display a piece of text that can be formated using stdio's printf() style.

IMPORTANT: this function can only be used within a begin*()/end*() block, otherwise it does nothing.

For instance if you want to display text mixed with numbers, you can use:

printf(frame, 10, 15, 0.4, 0xff0000, "Text: %d and %f", 7, 3.1415);

The size and color of the text will be based on cvui's default values.

Parameters

theFmt formating string as it would be supplied for stdio's printf(), e.g. "Text: %d and %f", 7, 3.1415.

See also: text(); beginColumn(); beginRow(); endRow(); endColumn()

Referenced by multiple-windows::compact(), input-change-counter::main(), input-react-key::main(), input-detect-key::main(), main-app::main(), hello-world::main(), mouse::main(), multiple-windows-complex::main(), mouse-complex::main(), interaction-area::main(), multiple-windows-complex-mouse::main(), mouse-complex-buttons::main(), on-image::main(), row-column::main(), and multiple-windows::window().

◆ printf() [2/4]

void cvui::printf	(	cv::Mat &	theWhere,
		int	theX,
		int	theY,
		const char *	theFmt,
			...
	)

Display a piece of text that can be formated using stdio's printf() style.

For instance if you want to display text mixed with numbers, you can use:

printf(frame, 10, 15, 0.4, 0xff0000, "Text: %d and %f", 7, 3.1415);

The size and color of the text will be based on cvui's default values.

Parameters

theWhere	image/frame where the component should be rendered.
theX	position X where the component should be placed.
theY	position Y where the component should be placed.
theFmt	formating string as it would be supplied for `stdio's printf()`, e.g. `"Text: %d and %f", 7, 3.1415`.

See also: text()

◆ printf() [3/4]

void cvui::printf	(	cv::Mat &	theWhere,
		int	theX,
		int	theY,
		double	theFontScale,
		unsigned int	theColor,
		const char *	theFmt,
			...
	)

Display a piece of text that can be formated using stdio's printf() style.

For instance if you want to display text mixed with numbers, you can use:

printf(frame, 10, 15, 0.4, 0xff0000, "Text: %d and %f", 7, 3.1415);

Parameters

theWhere	image/frame where the component should be rendered.
theX	position X where the component should be placed.
theY	position Y where the component should be placed.
theFontScale	size of the text.
theColor	color of the text in the format `0xRRGGBB`, e.g. `0xff0000` for red.
theFmt	formating string as it would be supplied for `stdio's printf()`, e.g. `"Text: %d and %f", 7, 3.1415`.

See also: text()

Referenced by compact(), main(), and window().

◆ printf() [4/4]

void cvui::printf	(	double	theFontScale,
		unsigned int	theColor,
		const char *	theFmt,
			...
	)

Display a piece of text within a begin*() and end*() block.

IMPORTANT: this function can only be used within a begin*()/end*() block, otherwise it does nothing.

The text can be formated using stdio's printf() style. For instance if you want to display text mixed with numbers, you can use:

printf(0.4, 0xff0000, "Text: %d and %f", 7, 3.1415);

Parameters

theFontScale	size of the text.
theColor	color of the text in the format `0xRRGGBB`, e.g. `0xff0000` for red.
theFmt	formating string as it would be supplied for `stdio's printf()`, e.g. `"Text: %d and %f", 7, 3.1415`.

See also: text(); beginColumn(); beginRow(); endRow(); endColumn()

◆ rect() [1/2]

void cvui::rect	(	cv::Mat &	theWhere,
		int	theX,
		int	theY,
		int	theWidth,
		int	theHeight,
		unsigned int	theBorderColor,
		unsigned int	theFillingColor = `0xff000000`
	)

Display a filled rectangle.

Parameters

theWhere	image/frame where the component should be rendered.
theX	position X where the component should be placed.
theY	position Y where the component should be placed.
theWidth	width of the rectangle.
theHeight	height of the rectangle.
theBorderColor	color of rectangle's border in the format `0xRRGGBB`, e.g. `0xff0000` for red.
theFillingColor	color of rectangle's filling in the format `0xAARRGGBB`, e.g. `0x00ff0000` for red, `0xff000000` for transparent filling.

See also: image()

Referenced by group(), and main().

◆ rect() [2/2]

void cvui::rect	(	int	theWidth,
		int	theHeight,
		unsigned int	theBorderColor,
		unsigned int	theFillingColor = `0xff000000`
	)

Display a rectangle within a begin*() and end*() block.

IMPORTANT: this function can only be used within a begin*()/end*() block, otherwise it does nothing.

Parameters

theWidth	width of the rectangle.
theHeight	height of the rectangle.
theBorderColor	color of rectangle's border in the format `0xRRGGBB`, e.g. `0xff0000` for red.
theFillingColor	color of rectangle's filling in the format `0xAARRGGBB`, e.g. `0x00ff0000` for red, `0xff000000` for transparent filling.

See also: window(); beginColumn(); beginRow(); endRow(); endColumn()

Referenced by complex-layout::group(), mouse::main(), mouse-complex::main(), interaction-area::main(), multiple-windows-complex::main(), mouse-complex-buttons::main(), and row-column::main().

◆ space()

void cvui::space ( int theValue = 5 )

Add an arbitrary amount of space between components within a begin*() and end*() block.

The function is aware of context, so if it is used within a beginColumn() and endColumn() block, the space will be vertical. If it is used within a beginRow() and endRow() block, space will be horizontal.

IMPORTANT: this function can only be used within a begin*()/end*() block, otherwise it does nothing.

Parameters

theValue the amount of space to be added.

See also: beginColumn(); beginRow(); endRow(); endColumn()

Referenced by main(), multiple-windows-complex::main(), nested-rows-columns::main(), on-image::main(), trackbar-complex::main(), ui-enhanced-window-component::main(), ui-enhanced-canny::main(), and row-column::main().

◆ sparkline() [1/2]

void cvui::sparkline	(	cv::Mat &	theWhere,
		std::vector< double > &	theValues,
		int	theX,
		int	theY,
		int	theWidth,
		int	theHeight,
		unsigned int	theColor = `0x00FF00`
	)

Display the values of a vector as a sparkline.

Parameters

theWhere	image/frame where the component should be rendered.
theValues	a vector containing the values to be used in the sparkline.
theX	position X where the component should be placed.
theY	position Y where the component should be placed.
theWidth	width of the sparkline.
theHeight	height of the sparkline.
theColor	color of sparkline in the format `0xRRGGBB`, e.g. `0xff0000` for red.

See also: trackbar()

Referenced by main().

◆ sparkline() [2/2]

void cvui::sparkline	(	std::vector< double > &	theValues,
		int	theWidth,
		int	theHeight,
		unsigned int	theColor = `0x00FF00`
	)

Display the values of a vector as a sparkline within a begin*() and end*() block.

IMPORTANT: this function can only be used within a begin*()/end*() block, otherwise it does nothing.

Parameters

theValues	vector with the values that will be rendered as a sparkline.
theWidth	width of the sparkline.
theHeight	height of the sparkline.
theColor	color of sparkline in the format `0xRRGGBB`, e.g. `0xff0000` for red.

See also: beginColumn(); beginRow(); endRow(); endColumn()

Referenced by multiple-windows-complex::main(), trackbar-sparkline::main(), row-column::main(), and sparkline::main().

◆ text() [1/2]

void cvui::text	(	const cv::String &	theText,
		double	theFontScale = `0.4`,
		unsigned int	theColor = `0xCECECE`
	)

Display a piece of text within a begin*() and end*() block.

IMPORTANT: this function can only be used within a begin*()/end*() block, otherwise it does nothing.

Parameters

theText	text content.
theFontScale	size of the text.
theColor	color of the text in the format `0xRRGGBB`, e.g. `0xff0000` for red.

See also: printf(); beginColumn(); beginRow(); endRow(); endColumn()

Referenced by complex-layout::group(), headless::main(), main-app::main(), image-button::main(), input-multiple::main(), input-sizes::main(), mouse::main(), input::main(), mouse-complex::main(), multiple-windows-complex::main(), mouse-complex-buttons::main(), nested-rows-columns::main(), trackbar::main(), trackbar-complex::main(), trackbar-sparkline::main(), button-shortcut::main(), ui-enhanced-window-component::main(), ui-enhanced-canny::main(), row-column::main(), multiple-windows-complex-dynamic::main(), and Class2.Class2::renderMessage().

◆ text() [2/2]

void cvui::text	(	cv::Mat &	theWhere,
		int	theX,
		int	theY,
		const cv::String &	theText,
		double	theFontScale = `0.4`,
		unsigned int	theColor = `0xCECECE`
	)

Display a piece of text.

Parameters

theWhere	image/frame where the component should be rendered.
theX	position X where the component should be placed.
theY	position Y where the component should be placed.
theText	the text content.
theFontScale	size of the text.
theColor	color of the text in the format `0xRRGGBB`, e.g. `0xff0000` for red.

See also: printf()

Referenced by group(), main(), and Class2::renderMessage().

◆ trackbar() [1/4]

template<typename num_type >

bool cvui::trackbar	(	cv::Mat &	theWhere,
		int	theX,
		int	theY,
		int	theWidth,
		num_type *	theValue,
		num_type	theMin,
		num_type	theMax,
		int	theSegments,
		const char *	theLabelFormat,
		unsigned int	theOptions,
		num_type	theDiscreteStep
	)

◆ trackbar() [2/4]

template<typename T >

bool cvui::trackbar	(	cv::Mat &	theWhere,
		int	theX,
		int	theY,
		int	theWidth,
		T *	theValue,
		T	theMin,
		T	theMax,
		int	theSegments = `1`,
		const char *	theLabelFormat = `"%.1Lf"`,
		unsigned int	theOptions = `0`,
		T	theDiscreteStep = `1`
	)

Display a trackbar for numeric values that the user can increase/decrease by clicking and/or dragging the marker right or left.

This component uses templates so it is imperative that you make it very explicit the type of theValue, theMin, theMax and theStep, otherwise you might end up with weird compilation errors.

Example:

// using double
trackbar(where, x, y, width, &doubleValue, 0.0, 50.0);
 
// using float
trackbar(where, x, y, width, &floatValue, 0.0f, 50.0f);
 
// using char
trackbar(where, x, y, width, &charValue, (char)1, (char)10);

Parameters

theWhere	image/frame where the component should be rendered.
theX	position X where the component should be placed.
theY	position Y where the component should be placed.
theWidth	the width of the trackbar.
theValue	the current value of the trackbar. It will be modified when the user interacts with the trackbar. Any numeric type can be used, e.g. float, double, long double, int, char, uchar.
theMin	minimum value allowed for the trackbar.
theMax	maximum value allowed for the trackbar.
theSegments	number of segments the trackbar will have (default is 1). Segments can be seen as groups of numbers in the scale of the trackbar. For example, 1 segment means a single groups of values (no extra labels along the scale), 2 segments mean the trackbar values will be divided in two groups and a label will be placed at the middle of the scale.
theLabelFormat	formating string that will be used to render the labels, e.g. `%.2Lf` (Lf not lf). No matter the type of the `theValue` param, internally trackbar stores it as a `long double`, so the formating string will always* receive a `long double` value to format. If you are using a trackbar with integers values, for instance, you can supress decimals using a formating string such as `%.0Lf` to format your labels.
theOptions	options to customize the behavior/appearance of the trackbar, expressed as a bitset. Available options are defined as `TRACKBAR_` constants and they can be combined using the bitwise `\|` operand. Available options are: `TRACKBAR_HIDE_SEGMENT_LABELS` (do not render segment labels, but do render min/max labels), `TRACKBAR_HIDE_STEP_SCALE` (do not render the small lines indicating values in the scale), `TRACKBAR_DISCRETE` (changes of the trackbar value are multiples of theDiscreteStep param), `TRACKBAR_HIDE_MIN_MAX_LABELS` (do not render min/max labels), `TRACKBAR_HIDE_VALUE_LABEL` (do not render the current value of the trackbar below the moving marker), `TRACKBAR_HIDE_LABELS` (do not render labels at all).
theDiscreteStep	amount that the trackbar marker will increase/decrease when the marker is dragged right/left (if option TRACKBAR_DISCRETE is ON)

Returns: true when the value of the trackbar changed.

See also: counter()

Referenced by main().

◆ trackbar() [3/4]

template<typename num_type >

bool cvui::trackbar	(	int	theWidth,
		num_type *	theValue,
		num_type	theMin,
		num_type	theMax,
		int	theSegments,
		const char *	theLabelFormat,
		unsigned int	theOptions,
		num_type	theDiscreteStep
	)

Referenced by main-app::main(), canny::main(), multiple-windows-complex::main(), trackbar::main(), on-image::main(), trackbar-complex::main(), trackbar-sparkline::main(), ui-enhanced-window-component::main(), and ui-enhanced-canny::main().

◆ trackbar() [4/4]

template<typename T >

bool cvui::trackbar	(	int	theWidth,
		T *	theValue,
		T	theMin,
		T	theMax,
		int	theSegments = `1`,
		const char *	theLabelFormat = `"%.1Lf"`,
		unsigned int	theOptions = `0`,
		T	theDiscreteStep = `1`
	)

Display a trackbar for numeric values that the user can increase/decrease by clicking and/or dragging the marker right or left.

IMPORTANT: this function can only be used within a begin*()/end*() block, otherwise it does nothing.

This component uses templates so it is imperative that you make it very explicit the type of theValue, theMin, theMax and theStep, otherwise you might end up with weird compilation errors.

Example:

// using double
trackbar(width, &doubleValue, 0.0, 50.0);
 
// using float
trackbar(width, &floatValue, 0.0f, 50.0f);
 
// using char
trackbar(width, &charValue, (char)1, (char)10);

Parameters

theWidth	the width of the trackbar.
theValue	the current value of the trackbar. It will be modified when the user interacts with the trackbar. Any numeric type can be used, e.g. float, double, long double, int, char, uchar.
theMin	minimum value allowed for the trackbar.
theMax	maximum value allowed for the trackbar.
theSegments	number of segments the trackbar will have (default is 1). Segments can be seen as groups of numbers in the scale of the trackbar. For example, 1 segment means a single groups of values (no extra labels along the scale), 2 segments mean the trackbar values will be divided in two groups and a label will be placed at the middle of the scale.
theLabelFormat	formating string that will be used to render the labels, e.g. `%.2Lf`. No matter the type of the `theValue` param, internally trackbar stores it as a `long double`, so the formating string will always receive a `long double` value to format. If you are using a trackbar with integers values, for instance, you can supress decimals using a formating string as `%.0Lf` to format your labels.
theOptions	options to customize the behavior/appearance of the trackbar, expressed as a bitset. Available options are defined as `TRACKBAR_` constants and they can be combined using the bitwise `\|` operand. Available options are: `TRACKBAR_HIDE_SEGMENT_LABELS` (do not render segment labels, but do render min/max labels), `TRACKBAR_HIDE_STEP_SCALE` (do not render the small lines indicating values in the scale), `TRACKBAR_DISCRETE` (changes of the trackbar value are multiples of informed step param), `TRACKBAR_HIDE_MIN_MAX_LABELS` (do not render min/max labels), `TRACKBAR_HIDE_VALUE_LABEL` (do not render the current value of the trackbar below the moving marker), `TRACKBAR_HIDE_LABELS` (do not render labels at all).
theDiscreteStep	the amount that the trackbar marker will increase/decrease when the marker is dragged right/left (if option TRACKBAR_DISCRETE is ON)

Returns: true when the value of the trackbar changed.

See also: counter(); beginColumn(); beginRow(); endRow(); endColumn()

◆ update()

void cvui::update ( const cv::String & theWindowName = "" )

Update the library internal things.

You need to call this function AFTER you are done adding/manipulating UI elements in order for them to react to mouse interactions.

Parameters

theWindowName name of the window whose components are being updated. If no window name is provided, cvui uses the default window.

See also: init(); watch(); context()

Referenced by input-change-counter::main(), image-button::main(), input-react-key::main(), input-sizes::main(), input-detect-key::main(), main-app::main(), input-multiple::main(), canny::main(), mouse-complex::main(), multiple-windows-complex::main(), input::main(), interaction-area::main(), main(), nested-rows-columns::main(), mouse-complex-buttons::main(), multiple-files::main(), button-shortcut::main(), trackbar-sparkline::main(), on-image::main(), trackbar-complex::main(), trackbar::main(), ui-enhanced-canny::main(), row-column::main(), sparkline::main(), multiple-windows-complex-dynamic::main(), complex-layout::main(), multiple-windows::window(), and window().

◆ watch()

void cvui::watch	(	const cv::String &	theWindowName,
		bool	theCreateNamedWindow = `true`
	)

Track UI interactions of a particular window.

This function must be invoked for any window that will receive cvui components. cvui automatically calls cvui::watch() for any window informed in cvui::init(), so generally you don't have to watch them yourself. If you initialized cvui and told it not to create windows automatically, you need to call cvui::watch() on those windows yourself. cvui::watch() can automatically create a window before watching it, if it does not exist.

Parameters

theWindowName	name of the window whose UI interactions will be tracked.
theCreateNamedWindow	if an OpenCV window named `theWindowName` should be created before it is watched. Windows are created using `cv::namedWindow()`. If this parameter is `false`, ensure you have called `cv::namedWindow(WINDOW_NAME)` to create the window, otherwise cvui will not be able to track its UI interactions.

See also: init(); context()

Referenced by main(), multiple-windows-complex::main(), multiple-windows-complex-dynamic::main(), multiple-windows-complex-dynamic::openWindow(), and openWindow().

◆ window() [1/2]

void cvui::window	(	cv::Mat &	theWhere,
		int	theX,
		int	theY,
		int	theWidth,
		int	theHeight,
		const cv::String &	theTitle
	)

Display a window (a block with a title and a body).

Parameters

theWhere	image/frame where the component should be rendered.
theX	position X where the component should be placed.
theY	position Y where the component should be placed.
theWidth	width of the window.
theHeight	height of the window.
theTitle	text displayed as the title of the window.

See also: rect()

Referenced by EnhancedWindow::begin(), group(), main(), and Class1::renderInfo().

◆ window() [2/2]

void cvui::window	(	int	theWidth,
		int	theHeight,
		const cv::String &	theTitle
	)

Display a window (a block with a title and a body) within a begin*() and end*() block.

IMPORTANT: this function can only be used within a begin*()/end*() block, otherwise it does nothing.

Parameters

theWidth	width of the window.
theHeight	height of the window.
theTitle	text displayed as the title of the window.

See also: rect(); beginColumn(); beginRow(); endRow(); endColumn()

Referenced by EnhancedWindow.EnhancedWindow::begin(), complex-layout::group(), main-app::main(), canny::main(), multiple-windows-complex::main(), on-image::main(), row-column::main(), and Class1.Class1::renderInfo().

Variable Documentation

◆ CLICK

const int cvui::CLICK = 3

Referenced by main().

◆ COLUMN

const int cvui::COLUMN = 1

◆ DOWN

const int cvui::DOWN = 2

Referenced by EnhancedWindow::begin(), and main().

◆ INTPUT_CURSOR_BLINK_SLOWNESS

const unsigned int cvui::INTPUT_CURSOR_BLINK_SLOWNESS = 10

◆ IS_DOWN

const int cvui::IS_DOWN = 7

Referenced by EnhancedWindow::begin(), and main().

◆ KEY_ARROW_DOWN

const unsigned int cvui::KEY_ARROW_DOWN = 2621440

◆ KEY_ARROW_LEFT

const unsigned int cvui::KEY_ARROW_LEFT = 2424832

◆ KEY_ARROW_RIGHT

const unsigned int cvui::KEY_ARROW_RIGHT = 2555904

◆ KEY_ARROW_UP

const unsigned int cvui::KEY_ARROW_UP = 2490368

◆ KEY_BACKSPACE

const unsigned int cvui::KEY_BACKSPACE = 8

◆ KEY_DELETE

const unsigned int cvui::KEY_DELETE = 3014656

◆ KEY_END

const unsigned int cvui::KEY_END = 2293760

◆ KEY_ENTER

const unsigned int cvui::KEY_ENTER = 13

Referenced by main().

◆ KEY_HOME

const unsigned int cvui::KEY_HOME = 2359296

◆ KEY_NONE

const unsigned int cvui::KEY_NONE = -1

◆ KEY_TAB

const unsigned int cvui::KEY_TAB = 9

◆ LEFT_BUTTON

const int cvui::LEFT_BUTTON = 0

Referenced by main().

◆ MIDDLE_BUTTON

const int cvui::MIDDLE_BUTTON = 1

◆ OUT

const int cvui::OUT = 5

Referenced by main().

◆ OVER

const int cvui::OVER = 4

Referenced by main().

◆ RIGHT_BUTTON

const int cvui::RIGHT_BUTTON = 2

Referenced by main().

◆ ROW

const int cvui::ROW = 0

◆ TRACKBAR_DISCRETE

const unsigned int cvui::TRACKBAR_DISCRETE = 4

Referenced by main().

◆ TRACKBAR_HIDE_LABELS

const unsigned int cvui::TRACKBAR_HIDE_LABELS = 32

◆ TRACKBAR_HIDE_MIN_MAX_LABELS

const unsigned int cvui::TRACKBAR_HIDE_MIN_MAX_LABELS = 8

◆ TRACKBAR_HIDE_SEGMENT_LABELS

const unsigned int cvui::TRACKBAR_HIDE_SEGMENT_LABELS = 1

Referenced by main().

◆ TRACKBAR_HIDE_STEP_SCALE

const unsigned int cvui::TRACKBAR_HIDE_STEP_SCALE = 2

◆ TRACKBAR_HIDE_VALUE_LABEL

const unsigned int cvui::TRACKBAR_HIDE_VALUE_LABEL = 16

◆ UP

const int cvui::UP = 6

Referenced by main().

Classes

Functions

Variables

Function Documentation

◆ beginColumn() [1/2]

◆ beginColumn() [2/2]

◆ beginRow() [1/2]

◆ beginRow() [2/2]

◆ button() [1/6]

◆ button() [2/6]

◆ button() [3/6]

◆ button() [4/6]

◆ button() [5/6]

◆ button() [6/6]

◆ checkbox() [1/2]

◆ checkbox() [2/2]

◆ context()

◆ counter() [1/4]

◆ counter() [2/4]

◆ counter() [3/4]

◆ counter() [4/4]

◆ endColumn()

◆ endRow()

◆ handleMouse()

◆ headless() [1/2]

◆ headless() [2/2]

◆ iarea()

◆ image() [1/2]

◆ image() [2/2]

◆ imshow()

◆ init() [1/2]

◆ init() [2/2]

◆ input()

◆ lastKeyPressed()

◆ mouse() [1/5]

◆ mouse() [2/5]

◆ mouse() [3/5]

◆ mouse() [4/5]

◆ mouse() [5/5]

◆ printf() [1/4]

◆ printf() [2/4]

◆ printf() [3/4]

◆ printf() [4/4]

◆ rect() [1/2]

◆ rect() [2/2]

◆ space()

◆ sparkline() [1/2]

◆ sparkline() [2/2]

◆ text() [1/2]

◆ text() [2/2]

◆ trackbar() [1/4]

◆ trackbar() [2/4]

◆ trackbar() [3/4]

◆ trackbar() [4/4]

◆ update()

◆ watch()

◆ window() [1/2]

◆ window() [2/2]

Variable Documentation

◆ CLICK

◆ COLUMN

◆ DOWN

◆ INTPUT_CURSOR_BLINK_SLOWNESS

◆ IS_DOWN

◆ KEY_ARROW_DOWN

◆ KEY_ARROW_LEFT

◆ KEY_ARROW_RIGHT

◆ KEY_ARROW_UP

◆ KEY_BACKSPACE

◆ KEY_DELETE

◆ KEY_END

◆ KEY_ENTER

◆ KEY_HOME

◆ KEY_NONE

◆ KEY_TAB

◆ LEFT_BUTTON

◆ MIDDLE_BUTTON

◆ OUT

◆ OVER

◆ RIGHT_BUTTON