#### 15.3.3.16 Uicontrol Properties ¶

Properties of `uicontrol` objects (see uicontrol):

#### Categories: ¶

Appearance | Callback Execution | Control Options | Creation/Deletion | Display | Mouse Interaction | Object Identification | Object Position | Parent/Children | Text Appearance

#### Appearance ¶

`backgroundcolor`: colorspec, def. `[0.9400 0.9400 0.9400]` ¶

  The color value of the background of this control object.

`cdata`: array, def. `[](0x0)` ¶

  Image data used to represent the control object, stored as a M x N x 3 RGB array.

`extent` (read-only): four-element vector ¶

  Size of the text string associated to the uicontrol returned in the form `[0 0 width height]` (the two first elements are always zero).

  For multi-line strings the returned `width` and `height` indicate the size of the rectangle enclosing all lines.

`foregroundcolor`: colorspec, def. `[0 0 0]` ¶

  The color value of the text for this control object. See colorspec.

`style`: `"checkbox"` | `"edit"` | `"frame"` | `"listbox"` | `"popupmenu"` | {`"pushbutton"`} | `"radiobutton"` | `"slider"` | `"text"` | `"togglebutton"` ¶

  The type of control object created. For a complete description of available control styles, see the `"uicontrol"` function

#### Callback Execution ¶

`busyaction`: `"cancel"` | {`"queue"`} ¶

  Define how Octave handles the execution of this object’s callback properties when it is unable to interrupt another object’s executing callback. This is only relevant when the currently executing callback object has its `interruptible` property set to `"off"`. The `busyaction` property of the interrupting callback object indicates whether the interrupting callback is queued (`"queue"` (default)) or discarded (`"cancel"`). See Callbacks section.

`callback`: string, def. `[](0x0)` ¶

  A string consisting of a valid Octave expression that will be executed whenever this control is activated.

`interruptible`: `"off"` | {`"on"`} ¶

  Specify whether this object’s callback functions may be interrupted by other callbacks. By default `interruptible` is `"on"` and callbacks that make use of `drawnow`, `figure`, `waitfor`, `getframe` or `pause` functions are eventually interrupted. See Callbacks section.

`keypressfcn`: string | function handle, def. `[](0x0)` ¶

  Callback function executed when a key is pressed while the uicontrol object has focus. The first argument to the function is the handle of the calling uicontrol. The second argument holds an event structure which has the following members:

  `Character:`

    The ASCII value of the key

  `Modifier:`

    A cell array containing strings representing the modifiers pressed with the key.

  `Key:`

    Lowercase description of the key

  `Source:`

    Graphics handle of the object executing the callback function

  `EventName:`

    "KeyPress"

  For information on how to write graphics listener functions, see Callbacks section.

#### Control Options ¶

`enable`: `"inactive"` | `"off"` | {`"on"`} ¶

  Sets whether this control object is active or is grayed out.

`listboxtop`: scalar, def. `1` ¶

  The index of the string option that will appear at the top of "listbox" controls

`max`: scalar, def. `1` ¶

  The maximum control value, whose effect on the control is dependent on the control type. For `"checkbox"`, `"togglebutton"`, and `"radiobutton"` controls, the `"max"` value is assigned to the `"value"` property when the control object is selected. For `"slider"` controls, `"max"` defines the maximum value of the slider. For `"edit"` and `"listbox"` controls, if `Max - Min > 1`, then the control will permit multiple line entries or list item selections, respectively.

`min`: scalar, def. `0` ¶

  The minimum control value, whose effect on the control is dependent on the control type. For `"checkbox"`, `"togglebutton"`, and `"radiobutton"` controls, the `"min"` value is assigned to the `"value"` property when the control object is not selected. For `"slider"` controls, `"min"` defines the minimum value of the slider. For `"edit"` and `"listbox"` controls, if `Max - Min > 1`, then the control will permit multiple line entries or list item selections, respectively.

`sliderstep`: two-element vector, def. `[0.010000 0.100000]` ¶

  The fractional step size, measured relative to the `Min - Max` span of the slider, that the slider moves when the user clicks on the object. `"sliderstep"` is specified as a two-element vector consisting of `[minor major]`, where `"minor"` is the step size for clicking on the slider arrows, and `"major"` is the step size for clicking within the slider bar.

`value`: scalar, def. `0` ¶

  A numerical value associated with the current state of the control object, with the meaning of the value dependent on the "style" of the control object.

#### Creation/Deletion ¶

`beingdeleted`: {`"off"`} | `"on"` ¶

  Property indicating that a function has initiated deletion of the object. `beingdeleted` is set to true until the object no longer exists.

`createfcn`: string | function handle, def. `[](0x0)` ¶

  Callback function executed immediately after uicontrol has been created. Function is set by using default property on root object, e.g., `set (groot, "defaultuicontrolcreatefcn", 'disp ("uicontrol created!")')`.

  For information on how to write graphics listener functions, see Callbacks section.

`deletefcn`: string | function handle, def. `[](0x0)` ¶

  Callback function executed immediately before uicontrol is deleted.

  For information on how to write graphics listener functions, see Callbacks section.

#### Display ¶

`clipping`: `"off"` | {`"on"`} ¶

  If `clipping` is `"on"`, the uicontrol is clipped in its parent axes limits.

`visible`: `"off"` | {`"on"`} ¶

  If `visible` is `"off"`, the uicontrol is not rendered on screen.

#### Mouse Interaction ¶

`buttondownfcn`: string | function handle, def. `[](0x0)` ¶

  For information on how to write graphics listener functions, see Callbacks section.

`contextmenu`: graphics handle, def. `[](0x0)` ¶

  Graphics handle of the uicontextmenu object that is currently associated to this uicontrol object.

`hittest`: `"off"` | {`"on"`} ¶

  Specify whether uicontrol processes mouse events or passes them to ancestors of the object. When enabled, the object may respond to mouse clicks by evaluating the `"buttondownfcn"`, showing the uicontextmenu, and eventually becoming the root `"currentobject"`. This property is only relevant when the object can accept mouse clicks which is determined by the `"pickableparts"` property. See pickableparts property.

`pickableparts`: `"all"` | `"none"` | {`"visible"`} ¶

  Specify whether uicontrol will accept mouse clicks. By default, `pickableparts` is `"visible"` and only visible parts of the uicontrol or its children may react to mouse clicks. When `pickableparts` is `"all"` both visible and invisible parts (or children) may react to mouse clicks. When `pickableparts` is `"none"` mouse clicks on the object are ignored and transmitted to any objects underneath this one. When an object is configured to accept mouse clicks the `"hittest"` property will determine how they are processed. See hittest property.

`selected`: {`"off"`} | `"on"` ¶

  Property indicates whether this uicontrol is selected.

`selectionhighlight`: `"off"` | {`"on"`} ¶

  If `selectionhighlight` is `"on"`, then the uicontrol’s selection state is visually highlighted.

`tooltipstring`: string, def. `""` ¶

  A text string that appears in a tooltip when the mouse pointer hovers over the control object.

#### Object Identification ¶

`tag`: string, def. `""` ¶

  A user-defined string to label the graphics object.

`type` (read-only): string ¶

  Class name of the graphics object. `type` is always `"uicontrol"`.

`userdata`: Any Octave data, def. `[](0x0)` ¶

  User-defined data to associate with the graphics object.

#### Object Position ¶

`position`: four-element vector, def. `[0 0 80 30]` ¶

  Size of the control object represented as the four-element vector [left, bottom, width, height].

`units`: `"centimeters"` | `"characters"` | `"inches"` | `"normalized"` | {`"pixels"`} | `"points"` ¶

  Unit of measurement used to interpret the `"position"` property.

#### Parent/Children ¶

`children` (read-only): vector of graphics handles, def. `[](0x0)` ¶

  Graphics handles of the uicontrol’s children.

`handlevisibility`: `"callback"` | `"off"` | {`"on"`} ¶

  If `handlevisibility` is `"off"`, the uicontrol’s handle is not visible in its parent’s `"children"` property.

`parent`: graphics handle ¶

  Handle of the parent graphics object.

#### Text Appearance ¶

`fontangle`: `"italic"` | {`"normal"`} ¶

  Control whether the font is italic or normal.

`fontname`: string, def. `"*"` ¶

  Name of font used for text rendering. When setting this property, the text rendering engine will search for a matching font in your system. If none is found then text is rendered using a default sans serif font (same as the default `"*"` value).

  Programming Note: On systems that don’t use FontConfig natively (all but Linux), the font cache is built when Octave is installed. You will need to run `system ("fc-cache -fv")` manually after installing new fonts.

`fontsize`: scalar, def. `10` ¶

  Size of the font used for text rendering. See fontunits property.

`fontunits`: `"centimeters"` | `"inches"` | `"normalized"` | `"pixels"` | {`"points"`} ¶

  Units used to interpret the `"fontsize"` property.

`fontweight`: `"bold"` | {`"normal"`} ¶

  Control the variant of the base font used for text rendering.

`horizontalalignment`: {`"center"`} | `"left"` | `"right"` ¶

  Specifies the horizontal justification of the text within the uicontrol object.

`string`: string, def. `""` ¶

  The text appearing with the control object.

`verticalalignment`: `"bottom"` | {`"middle"`} | `"top"` ¶

  Specifies the vertical position of the text in the uicontrol object.