1scrollbar(n) Tk Built-In Commands scrollbar(n)
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8 scrollbar - Create and manipulate scrollbar widgets
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11 scrollbar pathName ?options?
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14 -activebackground -highlightcolor -repeatdelay
15 -background -highlightthickness -repeatinterval
16 -borderwidth -jump -takefocus
17 -cursor -orient -troughcolor
18 -highlightbackground -relief
19 See the options manual entry for details on the standard options.
21
23 [-activerelief activeRelief] Specifies the relief to use when display‐
24 ing the element that is active, if any. Elements other than the active
25 element are always displayed with a raised relief. [-command command]
26 Specifies the prefix of a Tcl command to invoke to change the view in
27 the widget associated with the scrollbar. When a user requests a view
28 change by manipulating the scrollbar, a Tcl command is invoked. The
29 actual command consists of this option followed by additional informa‐
30 tion as described later. This option almost always has a value such as
31 .t xview or .t yview, consisting of the name of a widget and either
32 xview (if the scrollbar is for horizontal scrolling) or yview (for ver‐
33 tical scrolling). All scrollable widgets have xview and yview commands
34 that take exactly the additional arguments appended by the scrollbar as
35 described in SCROLLING COMMANDS below. [-elementborderwidth element‐
36 BorderWidth] Specifies the width of borders drawn around the internal
37 elements of the scrollbar (the two arrows and the slider). The value
38 may have any of the forms acceptable to Tk_GetPixels. If this value is
39 less than zero, the value of the borderWidth option is used in its
40 place. [-width width] Specifies the desired narrow dimension of the
41 scrollbar window, not including 3-D border, if any. For vertical
42 scrollbars this will be the width and for horizontal scrollbars this
43 will be the height. The value may have any of the forms acceptable to
44 Tk_GetPixels.
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46
48 The scrollbar command creates a new window (given by the pathName argu‐
49 ment) and makes it into a scrollbar widget. Additional options,
50 described above, may be specified on the command line or in the option
51 database to configure aspects of the scrollbar such as its colors, ori‐
52 entation, and relief. The scrollbar command returns its pathName argu‐
53 ment. At the time this command is invoked, there must not exist a win‐
54 dow named pathName, but pathName's parent must exist.
55 A scrollbar is a widget that displays two arrows, one at each end of
57 the scrollbar, and a slider in the middle portion of the scrollbar. It
58 provides information about what is visible in an associated window that
59 displays a document of some sort (such as a file being edited or a
60 drawing). The position and size of the slider indicate which portion
61 of the document is visible in the associated window. For example, if
62 the slider in a vertical scrollbar covers the top third of the area
63 between the two arrows, it means that the associated window displays
64 the top third of its document.
65 Scrollbars can be used to adjust the view in the associated window by
67 clicking or dragging with the mouse. See the BINDINGS section below
68 for details.
69
71 A scrollbar displays five elements, which are referred to in the widget
72 commands for the scrollbar:
73 arrow1 The top or left arrow in the scrollbar.
75 trough1 The region between the slider and arrow1.
77 slider The rectangle that indicates what is visible in the associ‐
79 ated widget.
80 trough2 The region between the slider and arrow2.
82 arrow2 The bottom or right arrow in the scrollbar.
84
86 The scrollbar command creates a new Tcl command whose name is pathName.
87 This command may be used to invoke various operations on the widget.
88 It has the following general form:
89 pathName option ?arg arg ...?
90 Option and the args determine the exact behavior of the command. The
91 following commands are possible for scrollbar widgets:
92 pathName activate ?element?
94 Marks the element indicated by element as active, which causes
95 it to be displayed as specified by the activeBackground and
96 activeRelief options. The only element values understood by
97 this command are arrow1, slider, or arrow2. If any other value
98 is specified then no element of the scrollbar will be active.
99 If element is not specified, the command returns the name of the
100 element that is currently active, or an empty string if no ele‐
101 ment is active.
102 pathName cget option
104 Returns the current value of the configuration option given by
105 option. Option may have any of the values accepted by the
106 scrollbar command.
107 pathName configure ?option? ?value option value ...?
109 Query or modify the configuration options of the widget. If no
110 option is specified, returns a list describing all of the avail‐
111 able options for pathName (see Tk_ConfigureInfo for information
112 on the format of this list). If option is specified with no
113 value, then the command returns a list describing the one named
114 option (this list will be identical to the corresponding sublist
115 of the value returned if no option is specified). If one or
116 more option-value pairs are specified, then the command modifies
117 the given widget option(s) to have the given value(s); in this
118 case the command returns an empty string. Option may have any
119 of the values accepted by the scrollbar command.
120 pathName delta deltaX deltaY
122 Returns a real number indicating the fractional change in the
123 scrollbar setting that corresponds to a given change in slider
124 position. For example, if the scrollbar is horizontal, the
125 result indicates how much the scrollbar setting must change to
126 move the slider deltaX pixels to the right (deltaY is ignored in
127 this case). If the scrollbar is vertical, the result indicates
128 how much the scrollbar setting must change to move the slider
129 deltaY pixels down. The arguments and the result may be zero or
130 negative.
131 pathName fraction x y
133 Returns a real number between 0 and 1 indicating where the point
134 given by x and y lies in the trough area of the scrollbar. The
135 value 0 corresponds to the top or left of the trough, the value
136 1 corresponds to the bottom or right, 0.5 corresponds to the
137 middle, and so on. X and y must be pixel coordinates relative
138 to the scrollbar widget. If x and y refer to a point outside
139 the trough, the closest point in the trough is used.
140 pathName get
142 Returns the scrollbar settings in the form of a list whose ele‐
143 ments are the arguments to the most recent set widget command.
144 pathName identify x y
146 Returns the name of the element under the point given by x and y
147 (such as arrow1), or an empty string if the point does not lie
148 in any element of the scrollbar. X and y must be pixel coordi‐
149 nates relative to the scrollbar widget.
150 pathName set first last
152 This command is invoked by the scrollbar's associated widget to
153 tell the scrollbar about the current view in the widget. The
154 command takes two arguments, each of which is a real fraction
155 between 0 and 1. The fractions describe the range of the docu‐
156 ment that is visible in the associated widget. For example, if
157 first is 0.2 and last is 0.4, it means that the first part of
158 the document visible in the window is 20% of the way through the
159 document, and the last visible part is 40% of the way through.
160
162 When the user interacts with the scrollbar, for example by dragging the
163 slider, the scrollbar notifies the associated widget that it must
164 change its view. The scrollbar makes the notification by evaluating a
165 Tcl command generated from the scrollbar's -command option. The com‐
166 mand may take any of the following forms. In each case, prefix is the
167 contents of the -command option, which usually has a form like .t yview
168 prefix moveto fraction
170 Fraction is a real number between 0 and 1. The widget should
171 adjust its view so that the point given by fraction appears at
172 the beginning of the widget. If fraction is 0 it refers to the
173 beginning of the document. 1.0 refers to the end of the docu‐
174 ment, 0.333 refers to a point one-third of the way through the
175 document, and so on.
176 prefix scroll number units
178 The widget should adjust its view by number units. The units
179 are defined in whatever way makes sense for the widget, such as
180 characters or lines in a text widget. Number is either 1, which
181 means one unit should scroll off the top or left of the window,
182 or -1, which means that one unit should scroll off the bottom or
183 right of the window.
184 prefix scroll number pages
186 The widget should adjust its view by number pages. It is up to
187 the widget to define the meaning of a page; typically it is
188 slightly less than what fits in the window, so that there is a
189 slight overlap between the old and new views. Number is either
190 1, which means the next page should become visible, or -1, which
191 means that the previous page should become visible.
192
194 In versions of Tk before 4.0, the set and get widget commands used a
195 different form. This form is still supported for backward compatibil‐
196 ity, but it is deprecated. In the old command syntax, the set widget
197 command has the following form:
198 pathName set totalUnits windowUnits firstUnit lastUnit
200 In this form the arguments are all integers. TotalUnits gives
201 the total size of the object being displayed in the associated
202 widget. The meaning of one unit depends on the associated wid‐
203 get; for example, in a text editor widget units might corre‐
204 spond to lines of text. WindowUnits indicates the total number
205 of units that can fit in the associated window at one time.
206 FirstUnit and lastUnit give the indices of the first and last
207 units currently visible in the associated window (zero corre‐
208 sponds to the first unit of the object).
209 Under the old syntax the get widget command returns a list of four
211 integers, consisting of the totalUnits, windowUnits, firstUnit, and
212 lastUnit values from the last set widget command.
213 The commands generated by scrollbars also have a different form when
215 the old syntax is being used:
216 prefix unit
218 Unit is an integer that indicates what should appear at the top
219 or left of the associated widget's window. It has the same
220 meaning as the firstUnit and lastUnit arguments to the set wid‐
221 get command.
222 The most recent set widget command determines whether or not to use the
224 old syntax. If it is given two real arguments then the new syntax will
225 be used in the future, and if it is given four integer arguments then
226 the old syntax will be used.
227
229 Tk automatically creates class bindings for scrollbars that give them
230 the following default behavior. If the behavior is different for ver‐
231 tical and horizontal scrollbars, the horizontal behavior is described
232 in parentheses.
233 [1] Pressing button 1 over arrow1 causes the view in the associated
235 widget to shift up (left) by one unit so that the document
236 appears to move down (right) one unit. If the button is held
237 down, the action auto-repeats.
238 [2] Pressing button 1 over trough1 causes the view in the associated
240 widget to shift up (left) by one screenful so that the document
241 appears to move down (right) one screenful. If the button is
242 held down, the action auto-repeats.
243 [3] Pressing button 1 over the slider and dragging causes the view
245 to drag with the slider. If the jump option is true, then the
246 view does not drag along with the slider; it changes only when
247 the mouse button is released.
248 [4] Pressing button 1 over trough2 causes the view in the associated
250 widget to shift down (right) by one screenful so that the docu‐
251 ment appears to move up (left) one screenful. If the button is
252 held down, the action auto-repeats.
253 [5] Pressing button 1 over arrow2 causes the view in the associated
255 widget to shift down (right) by one unit so that the document
256 appears to move up (left) one unit. If the button is held down,
257 the action auto-repeats.
258 [6] If button 2 is pressed over the trough or the slider, it sets
260 the view to correspond to the mouse position; dragging the
261 mouse with button 2 down causes the view to drag with the mouse.
262 If button 2 is pressed over one of the arrows, it causes the
263 same behavior as pressing button 1.
264 [7] If button 1 is pressed with the Control key down, then if the
266 mouse is over arrow1 or trough1 the view changes to the very top
267 (left) of the document; if the mouse is over arrow2 or trough2
268 the view changes to the very bottom (right) of the document; if
269 the mouse is anywhere else then the button press has no effect.
270 [8] In vertical scrollbars the Up and Down keys have the same behav‐
272 ior as mouse clicks over arrow1 and arrow2, respectively. In
273 horizontal scrollbars these keys have no effect.
274 [9] In vertical scrollbars Control-Up and Control-Down have the same
276 behavior as mouse clicks over trough1 and trough2, respectively.
277 In horizontal scrollbars these keys have no effect.
278 [10] In horizontal scrollbars the Up and Down keys have the same
280 behavior as mouse clicks over arrow1 and arrow2, respectively.
281 In vertical scrollbars these keys have no effect.
282 [11] In horizontal scrollbars Control-Up and Control-Down have the
284 same behavior as mouse clicks over trough1 and trough2, respec‐
285 tively. In vertical scrollbars these keys have no effect.
286 [12] The Prior and Next keys have the same behavior as mouse clicks
288 over trough1 and trough2, respectively.
289 [13] The Home key adjusts the view to the top (left edge) of the doc‐
291 ument.
292 [14] The End key adjusts the view to the bottom (right edge) of the
294 document.
295
297 Create a window with a scrollable text widget:
298 toplevel .tl
299 text .tl.t -yscrollcommand {.tl.s set}
300 scrollbar .tl.s -command {.tl.t yview}
301 grid .tl.t .tl.s -sticky nsew
302 grid columnconfigure .tl 0 -weight 1
303 grid rowconfigure .tl 0 -weight 1
304
306 ttk:scrollbar(n)
307
309 scrollbar, widget
310Tk 4.1 scrollbar(n)