Legend Properties

Legend appearance and behavior

Legend properties control the appearance and behavior of a Legend object. By changing property values, you can modify certain aspects of the legend. Use dot notation to refer to a particular object and property:

plot(rand(3))
lgd = legend('a','b','c');
c = lgd.TextColor;
lgd.TextColor = 'red';

Position and Layout

Location — Location with respect to axes

'north' | 'south' | 'east' | 'west' | 'northeast' | ...

Location with respect to the axes, specified as one of the location values listed in this table.

Value	Description
'north'	Inside top of axes
'south'	Inside bottom of axes
'east'	Inside right of axes
'west'	Inside left of axes
'northeast'	Inside top-right of axes (default for 2-D axes)
'northwest'	Inside top-left of axes
'southeast'	Inside bottom-right of axes
'southwest'	Inside bottom-left of axes
'northoutside'	Above the axes
'southoutside'	Below the axes
'eastoutside'	To the right of the axes
'westoutside'	To the left of the axes
'northeastoutside'	Outside top-right corner of the axes (default for 3-D axes)
'northwestoutside'	Outside top-left corner of the axes
'southeastoutside'	Outside bottom-right corner of the axes
'southwestoutside'	Outside bottom-left corner of the axes
'best'	Inside axes where least conflict with data in plot
'bestoutside'	Outside top-right corner of the axes (when the legend has a vertical orientation) or below the axes (when the legend has a horizontal orientation)
'none'	Determined by Position property. Use the Position property to specify a custom location.

Example: legend('Location','northeastoutside')

Orientation — Orientation

'vertical' (default) | 'horizontal'

Orientation, specified as one of these values:

• 'vertical' — Stack the legend items vertically. If the legend has multiple columns, layout the items from top to bottom along each column.

• 'horizontal' — List the legend items side-by-side. If the legend has multiple columns, layout the items from left to right along each row.

Example: legend('Orientation','horizontal')

NumColumns — Number of columns

1 (default) | positive integer

Number of columns, specified as a positive integer. If there are not enough legend items to fill the specified number of columns, then the number of columns that appear might be fewer.

Use the Orientation property to control whether the legend items appear in order along each column or along each row.

Example: lgd.NumColumns = 3

NumColumnsMode — Selection mode for NumColumns

'auto' (default) | 'manual'

Selection mode for the NumColumns value, specified as one of these values:

• 'auto' — Automatically select the value.

• 'manual' — Use the manually specified value. To specify the value, set the NumColumns property.

Position — Custom location and size

four-element vector

Custom location and size, specified as a four-element vector of the form [left bottom width height]. The first two values, left and bottom, specify the distance from the lower left corner of the figure to the lower left corner of the legend. The last two values, width and height, specify the legend dimensions. The Units property determines the position units.

If you specify the Position property, then MATLAB^® automatically changes the Location property to 'none'.

Example: legend({'A','B'},'Position',[0.2 0.6 0.1 0.2])

Note

Setting this property has no effect when the parent container is a TiledChartLayout.

Units — Position units

'normalized' (default) | 'inches' | 'centimeters' | 'characters' | 'points' | 'pixels'

Position units, specified as one of the values in this table.

Units	Description
'normalized' (default)	Normalized with respect to the container, which is usually the figure. The lower-left corner of the figure maps to (0,0) and the upper-right corner maps to (1,1). Resizing the figure updates the values of the Position vector.
'inches'	Inches.
'centimeters'	Centimeters.
'characters'	Based on the default system font character size. Character width = width of letter x. Character height = distance between the baselines of two lines of text.
'points'	Points. One point equals 1/72 inch.
'pixels'	Pixels. Starting in R2015b, distances in pixels are independent of your system resolution on Windows® and Macintosh systems. On Windows systems, a pixel is 1/96th of an inch. On Macintosh systems, a pixel is 1/72nd of an inch. On Linux® systems, the size of a pixel is determined by your system resolution.

All units are measured from the lower-left corner of the container window.

This property affects the Position property. If you change the units, then it is good practice to return it to its default value after completing your computation to prevent affecting other functions that assume Units is the default value.

If you specify the Position and Units properties as Name,Value pairs when creating the object, then the order of specification matters. If you want to define the position with particular units, then you must set the Units property before the Position property.

Labels

AutoUpdate — Automatic update of legend items

'on' (default) | on/off logical value

Automatic update of legend items to reflect the current state of the axes, specified as 'on' or 'off', or as numeric or logical 1 (true) or 0 (false). A value of 'on' is equivalent to true, and 'off' is equivalent to false. Thus, you can use the value of this property as a logical value. The value is stored as an on/off logical value of type matlab.lang.OnOffSwitchState.

• 'on' — Automatically add legend items for new graphics objects added to the axes. Remove legend items for graphics objects deleted from the axes.

• 'off' — Do not automatically add or delete legend items.

Example: legend({'A','B'},'AutoUpdate','off')

String — Text for legend labels

cell array of character vectors | string array | categorical array

Text for legend labels, specified as a cell array of character vectors, string array, or categorical array. To include special characters or Greek letters in the labels, use TeX markup. For a table of options, see the Interpreter property.

Title — Legend title

legend text object

Legend title, returned as a legend text object. To add a legend title, set the String property of the legend text object. To change the title appearance, such as the font style or color, set legend text properties. For a list, see Text Properties.

plot(rand(3));
lgd = legend('line 1','line 2','line 3');
lgd.Title.String = 'My Legend Title';
lgd.Title.FontSize = 12;

Alternatively, use the title function to add a title and control the appearance.

plot(rand(3));
lgd = legend('line 1','line 2','line 3');
title(lgd,'My Legend Title','FontSize',12)

Interpreter — Text interpreter

'tex' (default) | 'latex' | 'none'

Text interpreter, specified as one of these values:

• 'tex' — Interpret characters using a subset of TeX markup.

• 'latex' — Interpret characters using LaTeX markup.

• 'none' — Display literal characters.

TeX Markup

By default, MATLAB supports a subset of TeX markup. Use TeX markup to add superscripts and subscripts, modify the font type and color, and include special characters in the text.

Modifiers remain in effect until the end of the text. Superscripts and subscripts are an exception because they modify only the next character or the characters within the curly braces. When you set the interpreter to 'tex', the supported modifiers are as follows.

Modifier	Description	Example
^{ }	Superscript	'text^{superscript}'
_{ }	Subscript	'text_{subscript}'
\bf	Bold font	'\bf text'
\it	Italic font	'\it text'
\sl	Oblique font (usually the same as italic font)	'\sl text'
\rm	Normal font	'\rm text'
\fontname{specifier}	Font name — Replace specifier with the name of a font family. You can use this in combination with other modifiers.	'\fontname{Courier} text'
\fontsize{specifier}	Font size —Replace specifier with a numeric scalar value in point units.	'\fontsize{15} text'
\color{specifier}	Font color — Replace specifier with one of these colors: red, green, yellow, magenta, blue, black, white, gray, darkGreen, orange, or lightBlue.	'\color{magenta} text'
\color[rgb]{specifier}	Custom font color — Replace specifier with a three-element RGB triplet.	'\color[rgb]{0,0.5,0.5} text'

This table lists the supported special characters for the 'tex' interpreter.

Character Sequence	Symbol	Character Sequence	Symbol	Character Sequence	Symbol
\alpha	α	\upsilon	υ	\sim	~
\angle	∠	\phi		\leq	≤
\ast	*	\chi	χ	\infty	∞
\beta	β	\psi	ψ	\clubsuit	♣
\gamma	γ	\omega	ω	\diamondsuit	♦
\delta	δ	\Gamma	Γ	\heartsuit	♥
\epsilon	ϵ	\Delta	Δ	\spadesuit	♠
\zeta	ζ	\Theta	Θ	\leftrightarrow	↔
\eta	η	\Lambda	Λ	\leftarrow	←
\theta	θ	\Xi	Ξ	\Leftarrow	⇐
\vartheta	ϑ	\Pi	Π	\uparrow	↑
\iota	ι	\Sigma	Σ	\rightarrow	→
\kappa	κ	\Upsilon	ϒ	\Rightarrow	⇒
\lambda	λ	\Phi	Φ	\downarrow	↓
\mu	µ	\Psi	Ψ	\circ	º
\nu	ν	\Omega	Ω	\pm	±
\xi	ξ	\forall	∀	\geq	≥
\pi	π	\exists	∃	\propto	∝
\rho	ρ	\ni	∍	\partial	∂
\sigma	σ	\cong	≅	\bullet	•
\varsigma	ς	\approx	≈	\div	÷
\tau	τ	\Re	ℜ	\neq	≠
\equiv	≡	\oplus	⊕	\aleph	ℵ
\Im	ℑ	\cup	∪	\wp	℘
\otimes	⊗	\subseteq	⊆	\oslash	∅
\cap	∩	\in	∈	\supseteq	⊇
\supset	⊃	\lceil	⌈	\subset	⊂
\int	∫	\cdot	·	\o	ο
\rfloor	⌋	\neg	¬	\nabla	∇
\lfloor	⌊	\times	x	\ldots	...
\perp	⊥	\surd	√	\prime	´
\wedge	∧	\varpi	ϖ	\0	∅
\rceil	⌉	\rangle	〉	\mid	|
\vee	∨	\langle	〈	\copyright	©

LaTeX Markup

To use LaTeX markup, set the interpreter to 'latex'. Use dollar symbols around the text, for example, use '$\int_1^{20} x^2 dx$' for inline mode or '$$\int_1^{20} x^2 dx$$' for display mode.

The displayed text uses the default LaTeX font style. The FontName, FontWeight, and FontAngle properties do not have an effect. To change the font style, use LaTeX markup.

The maximum size of the text that you can use with the LaTeX interpreter is 1200 characters. For multiline text, this reduces by about 10 characters per line.

For more information about the LaTeX system, see The LaTeX Project website at https://www.latex-project.org/.

Font

FontName — Font name

supported font name | 'FixedWidth'

Font name, specified as a supported font name or 'FixedWidth'. To display and print text properly, you must choose a font that your system supports. The default font depends on your operating system and locale.

To use a fixed-width font that looks good in any locale, use 'FixedWidth'. The fixed-width font relies on the root FixedWidthFontName property. Setting the root FixedWidthFontName property causes an immediate update of the display to use the new font.

FontSize — Font size

scalar value greater than zero

Font size, specified as a scalar value greater than zero in point units. The default font size depends on the specific operating system and locale.

If you change the axes font size, then MATLAB automatically sets the font size of the colorbar to 90% of the axes font size. If you manually set the font size of the colorbar, then changing the axes font size does not affect the colorbar font.

FontWeight — Character thickness

'normal' (default) | 'bold'

Character thickness, specified as 'normal' or 'bold'.

MATLAB uses the FontWeight property to select a font from those available on your system. Not all fonts have a bold weight. Therefore, specifying a bold font weight can still result in the normal font weight.

FontAngle — Character slant

'normal' (default) | 'italic'

Character slant, specified as 'normal' or 'italic'.

Not all fonts have both font styles. Therefore, the italic font might look the same as the normal font.

Color and Styling

TextColor — Text color

[0 0 0] (default) | RGB triplet | hexadecimal color code | 'r' | 'g' | 'b' | ...

Text color, specified as an RGB triplet, a hexadecimal color code, a color name, or a short name. The default color is black with a value of [0 0 0].

For a custom color, specify an RGB triplet or a hexadecimal color code.

• An RGB triplet is a three-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0,1]; for example, [0.4 0.6 0.7].

• A hexadecimal color code is a character vector or a string scalar that starts with a hash symbol (#) followed by three or six hexadecimal digits, which can range from 0 to F. The values are not case sensitive. Thus, the color codes '#FF8800', '#ff8800', '#F80', and '#f80' are equivalent.

Alternatively, you can specify some common colors by name. This table lists the named color options, the equivalent RGB triplets, and hexadecimal color codes.

Color Name	Short Name	RGB Triplet	Hexadecimal Color Code	Appearance
'red'	'r'	[1 0 0]	'#FF0000'
'green'	'g'	[0 1 0]	'#00FF00'
'blue'	'b'	[0 0 1]	'#0000FF'
'cyan'	'c'	[0 1 1]	'#00FFFF'
'magenta'	'm'	[1 0 1]	'#FF00FF'
'yellow'	'y'	[1 1 0]	'#FFFF00'
'black'	'k'	[0 0 0]	'#000000'
'white'	'w'	[1 1 1]	'#FFFFFF'
'none'	Not applicable	Not applicable	Not applicable	No color

Here are the RGB triplets and hexadecimal color codes for the default colors MATLAB uses in many types of plots.

RGB Triplet	Hexadecimal Color Code	Appearance
[0 0.4470 0.7410]	'#0072BD'
[0.8500 0.3250 0.0980]	'#D95319'
[0.9290 0.6940 0.1250]	'#EDB120'
[0.4940 0.1840 0.5560]	'#7E2F8E'
[0.4660 0.6740 0.1880]	'#77AC30'
[0.3010 0.7450 0.9330]	'#4DBEEE'
[0.6350 0.0780 0.1840]	'#A2142F'

Example: [0 0 1]

Example: 'blue'

Example: '#0000FF'

Color — Background color

[1 1 1] (default) | RGB triplet | hexadecimal color code | 'r' | 'g' | 'b' | ...

Background color, specified as an RGB triplet, a hexadecimal color code, a color name, or a short name. The default value of [1 1 1] corresponds to white.

For a custom color, specify an RGB triplet or a hexadecimal color code.

• An RGB triplet is a three-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0,1]; for example, [0.4 0.6 0.7].

• A hexadecimal color code is a character vector or a string scalar that starts with a hash symbol (#) followed by three or six hexadecimal digits, which can range from 0 to F. The values are not case sensitive. Thus, the color codes '#FF8800', '#ff8800', '#F80', and '#f80' are equivalent.

Alternatively, you can specify some common colors by name. This table lists the named color options, the equivalent RGB triplets, and hexadecimal color codes.

Color Name	Short Name	RGB Triplet	Hexadecimal Color Code	Appearance
'red'	'r'	[1 0 0]	'#FF0000'
'green'	'g'	[0 1 0]	'#00FF00'
'blue'	'b'	[0 0 1]	'#0000FF'
'cyan'	'c'	[0 1 1]	'#00FFFF'
'magenta'	'm'	[1 0 1]	'#FF00FF'
'yellow'	'y'	[1 1 0]	'#FFFF00'
'black'	'k'	[0 0 0]	'#000000'
'white'	'w'	[1 1 1]	'#FFFFFF'
'none'	Not applicable	Not applicable	Not applicable	No color

Here are the RGB triplets and hexadecimal color codes for the default colors MATLAB uses in many types of plots.

RGB Triplet	Hexadecimal Color Code	Appearance
[0 0.4470 0.7410]	'#0072BD'
[0.8500 0.3250 0.0980]	'#D95319'
[0.9290 0.6940 0.1250]	'#EDB120'
[0.4940 0.1840 0.5560]	'#7E2F8E'
[0.4660 0.6740 0.1880]	'#77AC30'
[0.3010 0.7450 0.9330]	'#4DBEEE'
[0.6350 0.0780 0.1840]	'#A2142F'

Example: legend({'A','B'},'Color','y')

Example: legend({'A','B'},'Color',[0.8 0.8 1])

Example: legend({'A','B'},'Color','#D9A2E9')

EdgeColor — Box outline color

[0.15 0.15 0.15] (default) | RGB triplet | hexadecimal color code | 'r' | 'g' | 'b' | ...

Box outline color, specified as an RGB triplet, a hexadecimal color code, a color name, or a short name. The default value of [0.15 0.15 0.15] corresponds to dark gray.

For a custom color, specify an RGB triplet or a hexadecimal color code.

• An RGB triplet is a three-element row vector whose elements specify the intensities of the red, green, and blue components of the color. The intensities must be in the range [0,1]; for example, [0.4 0.6 0.7].

• A hexadecimal color code is a character vector or a string scalar that starts with a hash symbol (#) followed by three or six hexadecimal digits, which can range from 0 to F. The values are not case sensitive. Thus, the color codes '#FF8800', '#ff8800', '#F80', and '#f80' are equivalent.

Alternatively, you can specify some common colors by name. This table lists the named color options, the equivalent RGB triplets, and hexadecimal color codes.

Color Name	Short Name	RGB Triplet	Hexadecimal Color Code	Appearance
'red'	'r'	[1 0 0]	'#FF0000'
'green'	'g'	[0 1 0]	'#00FF00'
'blue'	'b'	[0 0 1]	'#0000FF'
'cyan'	'c'	[0 1 1]	'#00FFFF'
'magenta'	'm'	[1 0 1]	'#FF00FF'
'yellow'	'y'	[1 1 0]	'#FFFF00'
'black'	'k'	[0 0 0]	'#000000'
'white'	'w'	[1 1 1]	'#FFFFFF'
'none'	Not applicable	Not applicable	Not applicable	No color

Here are the RGB triplets and hexadecimal color codes for the default colors MATLAB uses in many types of plots.

RGB Triplet	Hexadecimal Color Code	Appearance
[0 0.4470 0.7410]	'#0072BD'
[0.8500 0.3250 0.0980]	'#D95319'
[0.9290 0.6940 0.1250]	'#EDB120'
[0.4940 0.1840 0.5560]	'#7E2F8E'
[0.4660 0.6740 0.1880]	'#77AC30'
[0.3010 0.7450 0.9330]	'#4DBEEE'
[0.6350 0.0780 0.1840]	'#A2142F'

Example: legend({'A','B'},'EdgeColor',[0 1 0])

Box — Display of box outline

'on' (default) | on/off logical value

Display of box outline, specified as 'on' or 'off', or as numeric or logical 1 (true) or 0 (false). A value of 'on' is equivalent to true, and 'off' is equivalent to false. Thus, you can use the value of this property as a logical value. The value is stored as an on/off logical value of type matlab.lang.OnOffSwitchState.

• 'on' — Display the box around the legend.

• 'off' — Do not display the box around the legend.

Example: legend({'A','B'},'Box','off')

LineWidth — Width of box outline

0.5 (default) | positive value

Width of box outline, specified as a positive value in point units. One point equals 1/72 inch.

Example: 1.5

Interactivity

Visible — State of visibility

'on' (default) | on/off logical value

State of visibility, specified as 'on' or 'off', or as numeric or logical 1 (true) or 0 (false). A value of 'on' is equivalent to true, and 'off' is equivalent to false. Thus, you can use the value of this property as a logical value. The value is stored as an on/off logical value of type matlab.lang.OnOffSwitchState.

• 'on' — Display the object.

• 'off' — Hide the object without deleting it. You still can access the properties of an invisible object.

ContextMenu — Context menu

ContextMenu object (default)

Context menu, specified as a ContextMenu object. Use this property to display a context menu when you right-click the object. Create the context menu using the uicontextmenu function.

Note

If the PickableParts property is set to 'none' or if the HitTest property is set to 'off', then the context menu does not appear.

Selected — Selection state

'off' (default) | on/off logical value

Selection state, specified as 'on' or 'off', or as numeric or logical 1 (true) or 0 (false). A value of 'on' is equivalent to true, and 'off' is equivalent to false. Thus, you can use the value of this property as a logical value. The value is stored as an on/off logical value of type matlab.lang.OnOffSwitchState.

• 'on' — Selected. If you click the object when in plot edit mode, then MATLAB sets its Selected property to 'on'. If the SelectionHighlight property also is set to 'on', then MATLAB displays selection handles around the object.

• 'off' — Not selected.

SelectionHighlight — Display of selection handles

'on' (default) | on/off logical value

Display of selection handles when selected, specified as 'on' or 'off', or as numeric or logical 1 (true) or 0 (false). A value of 'on' is equivalent to true, and 'off' is equivalent to false. Thus, you can use the value of this property as a logical value. The value is stored as an on/off logical value of type matlab.lang.OnOffSwitchState.

• 'on' — Display selection handles when the Selected property is set to 'on'.

• 'off' — Never display selection handles, even when the Selected property is set to 'on'.

Callbacks

ItemHitFcn — Callback that executes when you click legend items

@defaultItemHitCallback (default) | function handle | cell array | character vector

Callback that executes when you click legend items, specified as one of these values:

• Function handle. For example, @myCallback.

• Cell array containing a function handle and additional arguments. For example, {@myCallback,arg3}.

• Character vector that is a valid MATLAB command or function, which is evaluated in the base workspace (not recommended).

If you specify this property using a function handle, then MATLAB passes the Legend object and an event data structure as the first and second input arguments to the function. This table describes the fields in the event data structure.

Event Data Structure Fields

Field	Description
Peer	Chart object associated with the clicked legend item.
Region	Region of legend item clicked, returned as either 'icon' or 'label'.
SelectionType	Type of click, returned as one of these values: 'normal' — Single-click left mouse button 'extend' — Shift + single-click left mouse button 'open' — Double-click any mouse button 'alt' — Single-click right mouse button, both mouse buttons (Windows and Mac), or middle mouse button (Mac and Linux). If the ContextMenu property contains a valid context menu (which is the default), then this type of click opens the context menu instead of triggering the ItemHitFcn callback.
Source	Legend object.
EventName	Event name, 'ItemHit'.

Note

If you set the ButtonDownFcn property, then the ItemHitFcn property is disabled.

Example

You can create interactive legends so that when you click an item in the legend, the associated chart updates in some way. For example, you can toggle the visibility of the chart or change its line width. Set the ItemHitFcn property of the legend to a callback function that controls how the charts change. This example shows how to toggle the visibility of a chart when you click the chart icon or label in a legend. It creates a callback function that changes the Visible property of the chart to either 'on' or 'off'.

Copy the following code to a new function file and save it as hitcallback_ex1.m either in the current folder or in a folder on the MATLAB search path. The two input arguments, src and evnt, are the legend object and an event data structure. MATLAB automatically passes these inputs to the callback function when you click an item in the legend. Use the Peer field of the event data structure to access properties of the chart object associated with the clicked legend item.

function hitcallback_ex1(src,evnt)

if strcmp(evnt.Peer.Visible,'on')
    evnt.Peer.Visible = 'off';
else 
    evnt.Peer.Visible = 'on';
end

end

Then, plot four lines, create a legend, and assign the legend object to a variable. Set the ItemHitFcn property of the legend object to the callback function. Click items in the legend to show or hide the associated chart. The legend label changes to gray when you hide a chart.

plot(rand(4));
l = legend('Line 1','Line 2','Line 3','Line 4');
l.ItemHitFcn = @hitcallback_ex1;

ButtonDownFcn — Mouse-click callback

@bdowncb (default) | function handle | cell array | character vector

Mouse-click callback, specified as one of these values:

• Function handle

• Cell array containing a function handle and additional arguments

• Character vector that is a valid MATLAB command or function, which is evaluated in the base workspace (not recommended)

Use this property to execute code when you click the object. If you specify this property using a function handle, then MATLAB passes two arguments to the callback function when executing the callback:

• Clicked object — Access properties of the clicked object from within the callback function.

• Event data — Empty argument. Replace it with the tilde character (~) in the function definition to indicate that this argument is not used.

For more information on how to use function handles to define callback functions, see Callback Definition.

Note

If the PickableParts property is set to 'none' or if the HitTest property is set to 'off', then this callback does not execute.

CreateFcn — Creation function

'' (default) | function handle | cell array | character vector

Object creation function, specified as one of these values:

• Function handle.

• Cell array in which the first element is a function handle. Subsequent elements in the cell array are the arguments to pass to the callback function.

• Character vector containing a valid MATLAB expression (not recommended). MATLAB evaluates this expression in the base workspace.

For more information about specifying a callback as a function handle, cell array, or character vector, see Callback Definition.

This property specifies a callback function to execute when MATLAB creates the object. MATLAB initializes all property values before executing the CreateFcn callback. If you do not specify the CreateFcn property, then MATLAB executes a default creation function.

Setting the CreateFcn property on an existing component has no effect.

If you specify this property as a function handle or cell array, you can access the object that is being created using the first argument of the callback function. Otherwise, use the gcbo function to access the object.

DeleteFcn — Deletion function

'' (default) | function handle | cell array | character vector

Object deletion function, specified as one of these values:

• Function handle.

• Cell array in which the first element is a function handle. Subsequent elements in the cell array are the arguments to pass to the callback function.

• Character vector containing a valid MATLAB expression (not recommended). MATLAB evaluates this expression in the base workspace.

For more information about specifying a callback as a function handle, cell array, or character vector, see Callback Definition.

This property specifies a callback function to execute when MATLAB deletes the object. MATLAB executes the DeleteFcn callback before destroying the properties of the object. If you do not specify the DeleteFcn property, then MATLAB executes a default deletion function.

If you specify this property as a function handle or cell array, you can access the object that is being deleted using the first argument of the callback function. Otherwise, use the gcbo function to access the object.

Callback Execution Control

Interruptible — Callback interruption

'off' (default) | on/off logical value

Callback interruption, specified as 'on' or 'off', or as numeric or logical 1 (true) or 0 (false). A value of 'on' is equivalent to true, and 'off' is equivalent to false. Thus, you can use the value of this property as a logical value. The value is stored as an on/off logical value of type matlab.lang.OnOffSwitchState.

This property determines if a running callback can be interrupted. There are two callback states to consider:

• The running callback is the currently executing callback.

• The interrupting callback is a callback that tries to interrupt the running callback.

Whenever MATLAB invokes a callback, that callback attempts to interrupt a running callback. The Interruptible property of the object owning the running callback determines if interruption is permitted. The Interruptible property has two possible values:

• A value of 'on' allows other callbacks to interrupt the object's callbacks. The interruption occurs at the next point where MATLAB processes the queue, such as when there is a drawnow, figure, uifigure, getframe, waitfor, or pause command.

  • If the running callback contains one of those commands, then MATLAB stops the execution of the callback at that point and executes the interrupting callback. MATLAB resumes executing the running callback when the interrupting callback completes.

  • If the running callback does not contain one of those commands, then MATLAB finishes executing the callback without interruption.

• A value of 'off' blocks all interruption attempts. The BusyAction property of the object owning the interrupting callback determines if the interrupting callback is discarded or put into a queue.

BusyAction — Callback queuing

'queue' (default) | 'cancel'

Callback queuing, specified as 'queue' or 'cancel'. The BusyAction property determines how MATLAB handles the execution of interrupting callbacks. There are two callback states to consider:

• The running callback is the currently executing callback.

• The interrupting callback is a callback that tries to interrupt the running callback.

Whenever MATLAB invokes a callback, that callback attempts to interrupt a running callback. The Interruptible property of the object owning the running callback determines if interruption is permitted. If interruption is not permitted, then the BusyAction property of the object owning the interrupting callback determines if it is discarded or put in the queue. These are possible values of the BusyAction property:

• 'queue' — Puts the interrupting callback in a queue to be processed after the running callback finishes execution.

• 'cancel' — Does not execute the interrupting callback.

PickableParts — Ability to capture mouse clicks

'visible' (default) | 'none'

Ability to capture mouse clicks, specified as one of these values:

• 'visible' — Capture mouse clicks when visible. The Visible property must be set to 'on' and you must click a part of the Legend object that has a defined color. You cannot click a part that has an associated color property set to 'none'. The HitTest property determines if the Legend object responds to the click or if an ancestor does.

• 'none' — Cannot capture mouse clicks. Clicking the Legend object passes the click to the object below it in the current view of the figure window. The HitTest property of the Legend object has no effect.

HitTest — Response to captured mouse clicks

'on' (default) | on/off logical value

Response to captured mouse clicks, specified as 'on' or 'off', or as numeric or logical 1 (true) or 0 (false). A value of 'on' is equivalent to true, and 'off' is equivalent to false. Thus, you can use the value of this property as a logical value. The value is stored as an on/off logical value of type matlab.lang.OnOffSwitchState.

• 'on' — Trigger the ButtonDownFcn callback of the Legend object. If you have defined the ContextMenu property, then invoke the context menu.

• 'off' — Trigger the callbacks for the nearest ancestor of the Legend object that has one of these:

  • HitTest property set to 'on'

  • PickableParts property set to a value that enables the ancestor to capture mouse clicks

Note

The PickableParts property determines if the Legend object can capture mouse clicks. If it cannot, then the HitTest property has no effect.

BeingDeleted — Deletion status

on/off logical value

This property is read-only.

Deletion status, returned as an on/off logical value of type matlab.lang.OnOffSwitchState.

MATLAB sets the BeingDeleted property to 'on' when the DeleteFcn callback begins execution. The BeingDeleted property remains set to 'on' until the component object no longer exists.

Check the value of the BeingDeleted property to verify that the object is not about to be deleted before querying or modifying it.

Parent/Child

Parent — Parent container

Figure object | Panel object | Tab object | TiledChartLayout object

Parent container, specified as a Figure object, Panel object, Tab object, or a TiledChartLayout object.

The Legend object must have the same parent as the associated axes. If you change the parent of the associated axes, then the Legend object automatically updates to use the same parent.

Children — Children

empty GraphicsPlaceholder array

The object has no children. You cannot set this property.

HandleVisibility — Visibility of object handle

'on' (default) | 'off' | 'callback'

Visibility of the object handle in the Children property of the parent, specified as one of these values:

• 'on' — Object handle is always visible.

• 'off' — Object handle is invisible at all times. This option is useful for preventing unintended changes by another function. Set the HandleVisibility to 'off' to temporarily hide the handle during the execution of that function.

• 'callback' — Object handle is visible from within callbacks or functions invoked by callbacks, but not from within functions invoked from the command line. This option blocks access to the object at the command line, but permits callback functions to access it.

If the object is not listed in the Children property of the parent, then functions that obtain object handles by searching the object hierarchy or querying handle properties cannot return it. Examples of such functions include the get, findobj, gca, gcf, gco, newplot, cla, clf, and close functions.

Hidden object handles are still valid. Set the root ShowHiddenHandles property to 'on' to list all object handles regardless of their HandleVisibility property setting.

Identifiers

Type — Type of graphics object

'legend' (default)

This property is read-only.

Type of graphics object, returned as 'legend'. Use this property to find all objects of a given type within a plotting hierarchy.

Tag — Object identifier

'' (default) | character vector | string scalar

Object identifier, specified as a character vector or string scalar. You can specify a unique Tag value to serve as an identifier for an object. When you need access to the object elsewhere in your code, you can use the findobj function to search for the object based on the Tag value.

UserData — User data

[] (default) | array

User data, specified as any MATLAB array. For example, you can specify a scalar, vector, matrix, cell array, character array, table, or structure. Use this property to store arbitrary data on an object.

If you are working in App Designer, create public or private properties in the app to share data instead of using the UserData property. For more information, see Share Data Within App Designer Apps.

Compatibility Considerations

The UIContextMenu property is not recommended

Not recommended starting in R2020a

Starting in R2020a, setting or getting UIContextMenu property is not recommended. Instead, use the ContextMenu property, which accepts the same type of input and behaves the same way as the UIContextMenu property.

There are no plans to remove the UIContextMenu property at this time, but it is no longer listed when you call the set, get, or properties functions on the Legend object.