Module: Tk::Focus

Defined in:
lib/ffi-tk/command/focus.rb

Overview

Utility methods for managing the input focus.

Class Method Summary collapse

Class Method Details

.focus(window = None, option = None) ⇒ Object 



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# File 'lib/ffi-tk/command/focus.rb', line 6

def focus(window = None, option = None)
  if window == None
    Tk.execute('focus')
  else
    case option
    when None
      Tk.execute('focus', window)
    when :displayof
      Tk.execute('focus', '-displayof', window)
    when :force
      Tk.execute_only('focus', '-force', window)
    when :lastfor
      Tk.execute('focus', '-lastfor', window)
    else
      raise ArgumentError, "option must be one of: None, :displayof, :force, :lastfor"
    end
  end
end

.follows_mouse ⇒ Object

This method changes the focus model for the application to an implicit one where the window under the mouse gets the focus. After this method is called, whenever the mouse enters a window Tk will automatically give it the input focus. The focus command may be used to move the focus to a window other than the one under the mouse, but as soon as the mouse moves into a new window the focus will jump to that window.

Note: at present there is no built-in support for returning the application to an explicit focus model; to do this you will have to write a script that deletes the bindings created by tk_focusFollowsMouse.



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# File 'lib/ffi-tk/command/focus.rb', line 36

def follows_mouse
  Tk.execute_only(:tk_focusFollowsMouse)
end

.next(window) ⇒ Object

A method used for keyboard traversal. It returns the “next” window after window in focus order.

The focus order is determined by the stacking order of windows and the structure of the window hierarchy. Among siblings, the focus order is the same as the stacking order, with the lowest window being first.

If a window has children, the window is visited first, followed by its children (recursively), followed by its next sibling.

Top-level windows other than window are skipped, so that it never returns a window in a different top-level from window.

After computing the next window, it examines the window’s :takefocus option to see whether it should be skipped.

If so, it continues on to the next window in the focus order, until it eventually finds a window that will accept the focus or returns back to window.



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# File 'lib/ffi-tk/command/focus.rb', line 60

def next(window)
  Tk.execute(:tk_focusNext, window)
end

.prev(window) ⇒ Object

Similar to [Focus.next], except that it returns the window just before window in the focus order.



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# File 'lib/ffi-tk/command/focus.rb', line 66

def prev(window)
  Tk.execute(:tk_focusPrev, window)
end