class Tk::Scrollbar
Public Class Methods
# File lib/ffi-tk/widget/scrollbar.rb, line 6 def self.tk_command 'scrollbar' end
Public Instance Methods
Marks the element indicated by element as active, which causes it to be displayed as specified by the activeBackground and activeRelief options. The only element values understood by this command are arrow1, slider, or arrow2. If any other value is specified then no element of the scrollbar will be active. If element is not specified, the command returns the name of the element that is currently active, or an empty string if no element is active.
# File lib/ffi-tk/widget/scrollbar.rb, line 18 def activate(element = None) execute(:activate, element).to_s? end
Returns a real number indicating the fractional change in the scrollbar setting that corresponds to a given change in slider position. For example, if the scrollbar is horizontal, the result indicates how much the scrollbar setting must change to move the slider deltaX pixels to the right (deltaY is ignored in this case). If the scrollbar is vertical, the result indicates how much the scrollbar setting must change to move the slider deltaY pixels down. The arguments and the result may be zero or negative.
# File lib/ffi-tk/widget/scrollbar.rb, line 30 def delta(delta_x, delta_y) execute(:delta, delta_x, delta_y) end
Returns a real number between 0 and 1 indicating where the point given by x and y lies in the trough area of the scrollbar. The value 0 corresponds to the top or left of the trough, the value 1 corresponds to the bottom or right, 0.5 corresponds to the middle, and so on. X and y must be pixel coordinates relative to the scrollbar widget. If x and y refer to a point outside the trough, the closest point in the trough is used.
# File lib/ffi-tk/widget/scrollbar.rb, line 41 def fraction(x, y) execute(:fraction, x, y) end
Returns the scrollbar settings in the form of a list whose elements are the arguments to the most recent set widget command.
# File lib/ffi-tk/widget/scrollbar.rb, line 47 def get execute(:get) end
Returns the name of the element under the point given by x and y (such as arrow1), or an empty string if the point does not lie in any element of the scrollbar. X and y must be pixel coordinates relative to the scrollbar widget.
# File lib/ffi-tk/widget/scrollbar.rb, line 55 def identify(x, y) execute(:identify, x, y) end
This command is invoked by the scrollbar's associated widget to tell the scrollbar about the current view in the widget. The command takes two arguments, each of which is a real fraction between 0 and 1. The fractions describe the range of the document that is visible in the associated widget. For example, if first is 0.2 and last is 0.4, it means that the first part of the document visible in the window is 20% of the way through the document, and the last visible part is 40% of the way through. Fraction is a real number between 0 and 1. The widget should adjust its view so that the point given by fraction appears at the beginning of the widget. If fraction is 0 it refers to the beginning of the document. 1.0 refers to the end of the document, 0.333 refers to a point one-third of the way through the document, and so on. The widget should adjust its view by number units. The units are defined in whatever way makes sense for the widget, such as characters or lines in a text widget. Number is either 1, which means one unit should scroll off the top or left of the window, or -1, which means that one unit should scroll off the bottom or right of the window. The widget should adjust its view by number pages. It is up to the widget to define the meaning of a page; typically it is slightly less than what fits in the window, so that there is a slight overlap between the old and new views. Number is either 1, which means the next page should become visible, or -1, which means that the previous page should become visible.
In this form the arguments are all integers. TotalUnits gives the total size of the object being displayed in the associated widget. The meaning of one unit depends on the associated widget; for example, in a text editor widget units might correspond to lines of text. WindowUnits indicates the total number of units that can fit in the associated window at one time. FirstUnit and lastUnit give the indices of the first and last units currently visible in the associated window (zero corresponds to the first unit of the object). Unit is an integer that indicates what should appear at the top or left of the associated widget's window. It has the same meaning as the firstUnit and lastUnit arguments to the set widget command. the action auto-repeats. held down, the action auto-repeats. the mouse button is released. held down, the action auto-repeats. the action auto-repeats. button 2 is pressed over one of the arrows, it causes the same behavior as pressing button 1. the view changes to the very bottom (right) of the document; if the mouse is anywhere else then the button press has no effect. toplevel .tl text .tl.t -yscrollcommand {.tl.s set} scrollbar .tl.s -command {.tl.t yview} grid .tl.t .tl.s -sticky nsew grid columnconfigure .tl 0 -weight 1 grid rowconfigure .tl 0 -weight 1
# File lib/ffi-tk/widget/scrollbar.rb, line 113 def set(first, second, third = None, fourth = None) execute(:set, first, second, third, fourth) end