Altimeter Properties

Control altimeter appearance and behavior

Altimeters are components that represent an altimeter. Properties control the appearance and behavior of an altimeter. Use dot notation to refer to a particular object and property:

```f = uifigure; altimeter = uiaeroaltimeter(f); altimeter.Altitude = 100;```

The altimeter displays the altitude above sea level in feet, also known as the pressure altitude. It displays the altitude value with needles on a gauge and a numeric indicator.

• The gauge has 10 major ticks. Within each major tick are five minor ticks. This gauge has three needles. Using the needles, the altimeter can display accurately only altitudes between 0 and 100,000 feet.

• For the longest needle, an increment of a small tick represents 20 feet and a major tick represents 100 feet.

• For the second longest needle, a minor tick represents 200 feet and a major tick represents 1,000 feet.

• For the shortest needle a minor tick represents 2,000 feet and a major tick represents 10,000 feet.

• For the numeric display, the gauge shows values as numeric characters between 0 and 9,999 feet. When the numeric display value reaches 10,000 feet, the gauge displays the value as the remaining values below 10,000 feet. For example, 12,345 feet displays as 2,345 feet. When a value is less than 0 (below sea level), the gauge displays `0`. The needles show the appropriate value except for when the value is below sea level or over 100000 feet. Below sea level, the needles set to `0`, over 100,000, the needles stay set at 100,000.

Altimeter

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Altitude of the aircraft, specified as any finite and scalar numeric, in feet.

Example: `60`

Dependencies

Specifying this value changes the value of `Value`.

Data Types: `double`

Location of the aircraft altitude, specified as a finite and scalar numeric, in feet.

• Changing the value changes the direction of the heading in 5-degree increments.

Example: `60`

Dependencies

Specifying this value changes the value of the `Altitude` value.

Data Types: `double`

Interactivity

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Visibility of the altimeter, 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`. The `Visible` property determines whether the altimeter is displayed on the screen. If the `Visible` property is set to `'off'`, then the entire altimeter is hidden, but you can still specify and access its properties.

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

Operational state of altimeter, 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`.

• If you set this property to `'on'`, then the appearance of the altimeter indicates that the altimeter is operational.

• If you set this property to `'off'`, then the appearance of the altimeter appears dimmed, indicating that the altimeter is not operational.

Position

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Location and size of the altimeter relative to the parent container, specified as the vector, `[left bottom width height]`. This table describes each element in the vector.

ElementDescription
`left`Distance from the inner left edge of the parent container to the outer left edge of an imaginary box surrounding the altimeter
`bottom`Distance from the inner bottom edge of the parent container to the outer bottom edge of an imaginary box surrounding the altimeter
`width`Distance between the right and left outer edges of the altimeter
`height`Distance between the top and bottom outer edges of the altimeter

All measurements are in pixel units.

The `Position` values are relative to the drawable area of the parent container. The drawable area is the area inside the borders of the container and does not include the area occupied by decorations such as a menu bar or title.

Example: `[200 120 120 120]`

Inner location and size of the altimeter, specified as ```[left bottom width height]```. Position values are relative to the parent container. All measurements are in pixel units. This property value is identical to the `Position` property.

Outer location and size of the altimeter returned as ```[left bottom width height]```. Position values are relative to the parent container. All measurements are in pixel units. This property value is identical to the `Position` property.

Layout options, specified as a `GridLayoutOptions` object. This property specifies options for components that are children of grid layout containers. If the component is not a child of a grid layout container (for example, it is a child of a figure or panel), then this property is empty and has no effect. However, if the component is a child of a grid layout container, you can place the component in the desired row and column of the grid by setting the `Row` and `Column` properties on the `GridLayoutOptions` object.

For example, this code places an altimeter in the third row and second column of its parent grid.

```g = uigridlayout([4 3]); gauge = uiaeroaltimeter(g); gauge.Layout.Row = 3; gauge.Layout.Column = 2;```

To make the altimeter span multiple rows or columns, specify the `Row` or `Column` property as a two-element vector. For example, this altimeter spans columns `2` through `3`:

`gauge.Layout.Column = [2 3];`

Callbacks

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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 Callbacks in App Designer.

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.

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 Callbacks in App Designer.

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

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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.

MATLAB determines callback interruption behavior whenever it executes a command that processes the callback queue. These commands include `drawnow`, `figure`, `uifigure`, `getframe`, `waitfor`, and `pause`.

If the running callback does not contain one of these commands, then no interruption occurs. MATLAB first finishes executing the running callback, and later executes the interrupting callback.

If the running callback does contain one of these commands, then the `Interruptible` property of the object that owns the running callback determines if the interruption occurs:

• If the value of `Interruptible` is `'off'`, then no interruption occurs. Instead, the `BusyAction` property of the object that owns the interrupting callback determines if the interrupting callback is discarded or added to the callback queue.

• If the value of `Interruptible` is `'on'`, then the interruption occurs. The next time MATLAB processes the callback queue, it stops the execution of the running callback and executes the interrupting callback. After the interrupting callback completes, MATLAB then resumes executing the running callback.

Note

Callback interruption and execution behave differently in these situations:

• If the interrupting callback is a `DeleteFcn`, `CloseRequestFcn`, or `SizeChangedFcn` callback, then the interruption occurs regardless of the `Interruptible` property value.

• If the running callback is currently executing the `waitfor` function, then the interruption occurs regardless of the `Interruptible` property value.

• If the interrupting callback is owned by a `Timer` object, then the callback executes according to schedule regardless of the `Interruptible` property value.

Note

When an interruption occurs, MATLAB does not save the state of properties or the display. For example, the object returned by the `gca` or `gcf` command might change when another callback executes.

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.

The `BusyAction` property determines callback queuing behavior only when both of these conditions are met:

Under these conditions, the `BusyAction` property of the object that owns the interrupting callback determines how MATLAB handles the interrupting callback. 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.

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

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Visibility of the object handle, specified as `'on'`, `'callback'`, or `'off'`.

This property controls the visibility of the object in its parent's list of children. When an object is not visible in its parent's list of children, it is not returned by functions that obtain objects by searching the object hierarchy or querying properties. These functions include `get`, `findobj`, `clf`, and `close`. Objects are valid even if they are not visible. If you can access an object, you can set and get its properties, and pass it to any function that operates on objects.

HandleVisibility ValueDescription
`'on'`The object is always visible.
`'callback'`The object 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 allows callback functions to access it.
`'off'`The object is invisible at all times. This option is useful for preventing unintended changes to the UI by another function. Set the `HandleVisibility` to `'off'` to temporarily hide the object during the execution of that function.

Parent container, specified as a `Figure` object created using the `uifigure` function, or one of its child containers: `Tab`, `Panel`, `ButtonGroup`, or `GridLayout`. If no container is specified, MATLAB calls the `uifigure` function to create a new `Figure` object that serves as the parent container.

Identifiers

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Type of graphics object, returned as `'uiaeroaltimeter'`.

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.

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.

Version History

Introduced in R2018b