Radiobutton(3pm)

📦
version 804.036 · 15 versions
, in debian trixie, ubuntu questing

🎀 Radiobutton — the whole vibe 🎀

Bestie. Come sit. 🍓 This is Tk::Radiobutton, straight out of the User Contributed Perl Documentation, and it's about making little circle-and-diamond buttons that know how to pick themselves. Group-chat energy only, no cap. 💅

✨ NAME ✨

Tk::Radiobutton — create and manipulate Radiobutton widgets. That's it, that's the whole job. 👑

🌸 SYNOPSIS 🌸

$radiobutton = $parent->Radiobutton(?options?);

One line. Iconic behavior, honestly. 🦋

🫶 STANDARD OPTIONS 🫶

The classics, the ones every well-behaved widget shows up with:

-activebackground -activeforeground -anchor -background -bitmap -borderwidth -compound -cursor -disabledforeground -font -foreground -highlightbackground -highlightcolor -highlightthickness -image -justify -padx -pady -relief -takefocus -text -textvariable -underline -wraplength

Want the tea on any of these? Go read Tk::options, it spills all the details. ☕ (iykyk)

💖 WIDGET-SPECIFIC OPTIONS 💖

Here's where the radiobutton gets its own personality, its main character energy:

  • Name: command · Class: Command · Switch: -command — This is the perl/Tk callback you're tying to the button. Typically it fires when mouse button 1 gets released over the button window. Heads up though: the button's global variable (that's the -variable option) gets updated before the command is invoked. Order matters, bestie. 🫡
  • Name: height · Class: Height · Switch: -height — How tall do you want it? If an image or bitmap is being displayed in the button, the value is in screen units (i.e. any of the forms acceptable to Tk_GetPixels); for text it's in lines of text. Don't set it and the button just computes its own desired height from the size of the image, bitmap, or text it's displaying in it. Self-sufficient king. ✨
  • Name: indicatorOn · Class: IndicatorOn · Switch: -indicatoron — Should the indicator be drawn or not? Must be a proper boolean value, no vibes-based answers accepted. If false, the relief option is ignored and the widget's relief is always sunken if the widget is selected and raised otherwise. The way it just overrides your relief like that. 💀
  • Command-Line Name: -offrelief · Database Name: offRelief · Database Class: OffRelief — The relief for the checkbutton when the indicator is not drawn and the checkbutton is off. Default value is raised. Now the cute trick: set this option to flat and set -indicatoron false and -overrelief raised, and you get the effect of a flat button that raises on mouse-over and which is depressed when activated. That is literally the behavior typically exhibited by the Bold, Italic, and Underline checkbuttons on the toolbar of a word-processor. You know the ones. 🖊️
  • Command-Line Name: -overrelief · Database Name: overRelief · Database Class: OverRelief — An alternative relief for the button, used when the mouse cursor is over the widget. Use it to make toolbar buttons, by configuring -relief flat -overrelief raised. If the value of this option is the empty string, then no alternative relief is used when the mouse cursor is over the button. And the empty string is the default value. 🎀
  • Name: selectColor · Class: Background · Switch: -selectcolor — A background color to use when the button is selected. If indicatorOn is true then the color applies to the indicator. Under Windows, this color is used as the background for the indicator regardless of the select state. If indicatorOn is false, this color is used as the background for the entire widget, in place of background or activeBackground, whenever the widget is selected. Specify it as an empty string and no special color is used for displaying when the widget is selected. 🌈
  • Name: selectImage · Class: SelectImage · Switch: -selectimage — An image to display (in place of the image option) when the radiobutton is selected. Lowkey important: this option is ignored unless the image option has been specified. Set image first, bestie. 🙈
  • Name: state · Class: State · Switch: -state — Pick one of three states: normal, active, or disabled.
    • In normal state the radiobutton is displayed using the foreground and background options.
    • The active state is typically used when the pointer is over the radiobutton; in it the radiobutton is displayed using the activeForeground and activeBackground options.
    • disabled means the radiobutton should be insensitive: the default bindings will refuse to activate the widget and will ignore mouse button presses. In this state the disabledForeground and background options determine how the radiobutton is displayed. Not me putting a widget in time-out. 😭
  • Name: value · Class: Value · Switch: -value — The value to store in the button's associated variable whenever this button is selected. That's the whole job. 🫶
  • Name: variable · Class: Variable · Switch: -variable — A reference to a variable to set whenever this button is selected. Changes in this variable also cause the button to select or deselect itself. Defaults to the value \$Tk::selectedButton. 👑
  • Name: width · Class: Width · Switch: -width — Desired width for the button. If an image or bitmap is being displayed in the button, the value is in screen units (any of the forms acceptable to Tk_GetPixels); for text it's in characters. Leave it unset and the button's desired width is computed from the size of the image, bitmap, or text being displayed in it. Self-computing icon. ⭐

🦋 DESCRIPTION 🦋

The Radiobutton method creates a new window (given by the $widget argument) and makes it into a radiobutton widget. Additional options, described above, may be specified on the command line or in the option database to configure aspects of the radiobutton such as its colors, font, text, and initial relief. The radiobutton command returns its $widget argument. And listen: at the time this command is invoked, there must not exist a window named $widget, but $widget's parent must exist. Rules are rules. 💅

So what even is a radiobutton? It's a widget that displays a textual string, bitmap, or image, plus a diamond or circle called an indicator. If text is displayed, it must all be in a single font, but it can occupy multiple lines on the screen (if it contains newlines, or if wrapping occurs because of the wrapLength option), and one of the characters may optionally be underlined using the underline option. A radiobutton has all of the behavior of a simple button: it can display itself in any of three different ways according to the state option; it can be made to appear raised, sunken, or flat; it can be made to flash; and it invokes a perl/Tk callback whenever mouse button 1 is clicked over the check button.

In addition, radiobuttons can be selected. If a radiobutton is selected, the indicator is normally drawn with a selected appearance, and a Tcl variable associated with the radiobutton is set to a particular value (normally 1). Under Unix, the indicator is drawn with a sunken relief and a special color. Under Windows, the indicator is drawn with a round mark inside. If the radiobutton is not selected, then the indicator is drawn with a deselected appearance, and the associated variable is set to a different value (typically 0). Under Unix, the indicator is drawn with a raised relief and no special color. Under Windows, the indicator is drawn without a round mark inside.

Typically, several radiobuttons share a single variable, and the value of that variable indicates which radiobutton is to be selected. When a radiobutton is selected it sets the value of the variable to indicate that fact; each radiobutton also monitors the value of the variable and automatically selects and deselects itself when the variable's value changes. By default the variable selectedButton is used; its contents give the name of the button that is selected, or the empty string if no button associated with that variable is selected. The name of the variable for a radiobutton, plus the variable to be stored into it, may be modified with options on the command line or in the option database. Configuration options may also be used to modify the way the indicator is displayed (or whether it's displayed at all). By default a radiobutton is configured to select itself on button clicks. Group chat behavior, honestly. ✨

🧚 WIDGET METHODS 🧚

The Radiobutton method creates a widget object. This object supports the configure and cget methods described in Tk::options, which you can use to enquire about and modify the options described above. The widget also inherits all the methods provided by the generic Tk::Widget class. Nepo baby but make it useful. 👑

The following additional methods are available for radiobutton widgets:

  • $radiobutton->deselect — Deselects the radiobutton and sets the associated variable to an empty string. If this radiobutton was not currently selected, the command has no effect. No harm, no foul. 💜
  • $radiobutton->flash — Flashes the radiobutton. How? By redisplaying the radiobutton several times, alternating between active and normal colors. At the end of the flash the radiobutton is left in the same normal/active state as when the command was invoked. This command is ignored if the radiobutton's state is disabled. So if it's disabled, no flash for you. 😭
  • $radiobutton->invoke — Does just what would have happened if the user invoked the radiobutton with the mouse: selects the button and invokes its associated Tcl command, if there is one. The return value is the return value from the Tcl command, or an empty string if there is no command associated with the radiobutton. This command is ignored if the radiobutton's state is disabled. 🫡
  • $radiobutton->select — Selects the radiobutton and sets the associated variable to the value corresponding to this widget. Simple. Slay. 💅

🔥 BINDINGS 🔥

Tk automatically creates class bindings for radiobuttons that give them the following default behavior:

  1. On Unix systems, a radiobutton activates whenever the mouse passes over it and deactivates whenever the mouse leaves the radiobutton. On Mac and Windows systems, when mouse button 1 is pressed over a radiobutton, the button activates whenever the mouse pointer is inside the button, and deactivates whenever the mouse pointer leaves the button. 🌸
  2. When mouse button 1 is pressed over a radiobutton it is invoked (it becomes selected and the command associated with the button is invoked, if there is one). ⭐
  3. When a radiobutton has the input focus, the space key causes the radiobutton to be invoked. 🎀
Careful bestie: if the radiobutton's state is disabled then none of the above actions occur — the radiobutton is completely non-responsive. Like a read receipt that never comes. 💀

The behavior of radiobuttons can be changed by defining new bindings for individual widgets or by redefining the class bindings. Customize away. 🦋

🌈 KEYWORDS 🌈

radiobutton, widget

And that's the whole page, fr fr. 💖 This one came out of the User Contributed Perl Documentation, from perl v5.40.1, dated 2025-04-13. Thanks for coming to my TED talk, bestie — now go make some buttons that actually know how to share a variable. 🫶✨💅

📦 where this page comes from