class Iup::Widget

This class provides shared functionality across all widgets in the IUP library.

Every widget has a handle, which is often a C pointer:

p Iup::Button.new.handle
# => #<FFI::Pointer address=0x0000647e530e6a80>

The Widget class provides attributes supporting appearance, including whether the widget is active, its size, font and color, and its position in the z-order list (where widgets are overlapping, and the top one is visible).

Some common callbacks are also found in this class, responding to:

map/unmap, where the native interface elements are created. Some child widgets require their parent to be mapped first.
focus events.
keyboard/mouse events.

The following code creates a button with large red text, which reports when the mouse moves over the button and any key is pressed:

Iup::mainloop do
  btn = Iup::Button.new("hello") do
    it.fgcolor = "255 0 0"
    it.font = "Times, Bold 18"
    it.enterwindow_cb = ->{ puts "on button" }
    it.leavewindow_cb = ->{ puts "off button" }
    it.k_any = ->(k){ puts "Key #{k.chr}" }
  end

  Iup::Dialog.new(btn).show
end

Attributes

active [RW]

Enables or prevents user interaction. Typically, a widget will appear greyed-out when inactive. Values ‘yes’ / ‘no’.

bgcolor [RW]

Specify RGB values for background color, as “r g b”.

fgcolor [RW]

Specify RGB values for foreground color, as “r g b”.

font [RW]

Sets the widget’s font, using a font description as “<font face>, <font styles> <font size>”, e.g. “Times, Bold 14”. For portability, the fonts Courier, Helvetica and Times are always mapped to appropriate native system fonts.

handle [RW]

Unique reference to widget.

maxsize [RW]

Maximum size of widget, value as “widthxheight”.

minsize [RW]

Minimum size of widget, value as “widthxheight”.

size [RW]

Size of the widget, in character units, value as “widthxheight”.

visible [RW]

Shows or hides the widget. Values ‘yes’ / ‘no’.

wid [R]

Native widget identifier.

zorder [W]

Alters z-order, values as ‘top’ / ‘bottom’.

Public Instance Methods

assign_handle (name)

Source

# File lib/wrapped/widget.rb, line 47
def assign_handle name
  IupLib.IupSetHandle(name, @handle)
end

Sets the internal handle name for this widget.

destroy ()

Source

# File lib/wrapped/widget.rb, line 120
def destroy
  IupLib.IupDestroy @handle
end

When no longer required, call destroy to have the C backend reclaim the widget.

open_controls ()

Source

# File lib/wrapped/widget.rb, line 54
def open_controls
  unless @@controlslib
    ControlsLib.IupControlsOpen
    @@controlslib = true
  end
end

Ensure the controls library is opened

Callbacks

Attributes

enterwindow_cb [W]

Action generated when the mouse enters the widget. Callback must respond to call and take no arguments.

getfocus_cb [W]

Action generated when a widget is given keyboard focus. Callback must respond to call and take no arguments.

help_cb [W]

Action generated when the user presses F1 at a control. Callback must respond to call and take no arguments.

k_any [W]

Action generated when a keyboard event occurs. Callback must respond to call and takes 1-argument: (key)

key - the character that is pressed, see Key definitions.

killfocus_cb [W]

Action generated when a widget loses keyboard focus. Callback must respond to call and take no arguments.

leavewindow_cb [W]

Action generated when the mouse leaves the widget. Callback must respond to call and take no arguments.

map_cb [W]

Called right after a widget is mapped and its layout updated. Callback must respond to call and take no arguments.

unmap_cb [W]

Called right before a widget is unmapped. Callback must respond to call and take no arguments.

class Iup::Widget

Example