1scrollbar(n) Tk Built-In Commands scrollbar(n)
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6
8 scrollbar - Create and manipulate 'scrollbar' scrolling control and
9 indicator widgets
10
12 scrollbar pathName ?options?
13
15 -activebackground -highlightcolor -repeatdelay
16 -background -highlightthickness -repeatinterval
17 -borderwidth -jump -takefocus
18 -cursor -orient -troughcolor
19 -highlightbackground -relief
20 See the options manual entry for details on the standard options.
22
24 Command-Line Name:-activerelief
25 Database Name: activeRelief
26 Database Class: ActiveRelief
27 Specifies the relief to use when displaying the element that is
29 active, if any. Elements other than the active element are
30 always displayed with a raised relief.
31 Command-Line Name:-command
33 Database Name: command
34 Database Class: Command
35 Specifies the prefix of a Tcl command to invoke to change the
37 view in the widget associated with the scrollbar. When a user
38 requests a view change by manipulating the scrollbar, a Tcl com‐
39 mand is invoked. The actual command consists of this option
40 followed by additional information as described later. This
41 option almost always has a value such as .t xview or .t yview,
42 consisting of the name of a widget and either xview (if the
43 scrollbar is for horizontal scrolling) or yview (for vertical
44 scrolling). All scrollable widgets have xview and yview com‐
45 mands that take exactly the additional arguments appended by the
46 scrollbar as described in SCROLLING COMMANDS below.
47 Command-Line Name:-elementborderwidth
49 Database Name: elementBorderWidth
50 Database Class: BorderWidth
51 Specifies the width of borders drawn around the internal ele‐
53 ments of the scrollbar (the two arrows and the slider). The
54 value may have any of the forms acceptable to Tk_GetPixels. If
55 this value is less than zero, the value of the -borderwidth
56 option is used in its place.
57 Command-Line Name:-width
59 Database Name: width
60 Database Class: Width
61 Specifies the desired narrow dimension of the scrollbar window,
63 not including 3-D border, if any. For vertical scrollbars this
64 will be the width and for horizontal scrollbars this will be the
65 height. The value may have any of the forms acceptable to
66 Tk_GetPixels.
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68
70 The scrollbar command creates a new window (given by the pathName argu‐
71 ment) and makes it into a scrollbar widget. Additional options,
72 described above, may be specified on the command line or in the option
73 database to configure aspects of the scrollbar such as its colors, ori‐
74 entation, and relief. The scrollbar command returns its pathName argu‐
75 ment. At the time this command is invoked, there must not exist a win‐
76 dow named pathName, but pathName's parent must exist.
77 A scrollbar is a widget that displays two arrows, one at each end of
79 the scrollbar, and a slider in the middle portion of the scrollbar. It
80 provides information about what is visible in an associated window that
81 displays a document of some sort (such as a file being edited or a
82 drawing). The position and size of the slider indicate which portion
83 of the document is visible in the associated window. For example, if
84 the slider in a vertical scrollbar covers the top third of the area
85 between the two arrows, it means that the associated window displays
86 the top third of its document.
87 Scrollbars can be used to adjust the view in the associated window by
89 clicking or dragging with the mouse. See the BINDINGS section below
90 for details.
91
93 A scrollbar displays five elements, which are referred to in the widget
94 commands for the scrollbar:
95 arrow1 The top or left arrow in the scrollbar.
97 trough1 The region between the slider and arrow1.
99 slider The rectangle that indicates what is visible in the associ‐
101 ated widget.
102 trough2 The region between the slider and arrow2.
104 arrow2 The bottom or right arrow in the scrollbar.
106
108 The scrollbar command creates a new Tcl command whose name is pathName.
109 This command may be used to invoke various operations on the widget.
110 It has the following general form:
111 pathName option ?arg arg ...?
112 Option and the args determine the exact behavior of the command. The
113 following commands are possible for scrollbar widgets:
114 pathName activate ?element?
116 Marks the element indicated by element as active, which causes
117 it to be displayed as specified by the -activebackground and
118 -activerelief options. The only element values understood by
119 this command are arrow1, slider, or arrow2. If any other value
120 is specified then no element of the scrollbar will be active.
121 If element is not specified, the command returns the name of the
122 element that is currently active, or an empty string if no ele‐
123 ment is active.
124 pathName cget option
126 Returns the current value of the configuration option given by
127 option. Option may have any of the values accepted by the
128 scrollbar command.
129 pathName configure ?option? ?value option value ...?
131 Query or modify the configuration options of the widget. If no
132 option is specified, returns a list describing all of the avail‐
133 able options for pathName (see Tk_ConfigureInfo for information
134 on the format of this list). If option is specified with no
135 value, then the command returns a list describing the one named
136 option (this list will be identical to the corresponding sublist
137 of the value returned if no option is specified). If one or
138 more option-value pairs are specified, then the command modifies
139 the given widget option(s) to have the given value(s); in this
140 case the command returns an empty string. Option may have any
141 of the values accepted by the scrollbar command.
142 pathName delta deltaX deltaY
144 Returns a real number indicating the fractional change in the
145 scrollbar setting that corresponds to a given change in slider
146 position. For example, if the scrollbar is horizontal, the
147 result indicates how much the scrollbar setting must change to
148 move the slider deltaX pixels to the right (deltaY is ignored in
149 this case). If the scrollbar is vertical, the result indicates
150 how much the scrollbar setting must change to move the slider
151 deltaY pixels down. The arguments and the result may be zero or
152 negative.
153 pathName fraction x y
155 Returns a real number between 0 and 1 indicating where the point
156 given by x and y lies in the trough area of the scrollbar. The
157 value 0 corresponds to the top or left of the trough, the value
158 1 corresponds to the bottom or right, 0.5 corresponds to the
159 middle, and so on. X and y must be pixel coordinates relative
160 to the scrollbar widget. If x and y refer to a point outside
161 the trough, the closest point in the trough is used.
162 pathName get
164 Returns the scrollbar settings in the form of a list whose ele‐
165 ments are the arguments to the most recent set widget command.
166 pathName identify x y
168 Returns the name of the element under the point given by x and y
169 (such as arrow1), or an empty string if the point does not lie
170 in any element of the scrollbar. X and y must be pixel coordi‐
171 nates relative to the scrollbar widget.
172 pathName set first last
174 This command is invoked by the scrollbar's associated widget to
175 tell the scrollbar about the current view in the widget. The
176 command takes two arguments, each of which is a real fraction
177 between 0 and 1. The fractions describe the range of the docu‐
178 ment that is visible in the associated widget. For example, if
179 first is 0.2 and last is 0.4, it means that the first part of
180 the document visible in the window is 20% of the way through the
181 document, and the last visible part is 40% of the way through.
182
184 When the user interacts with the scrollbar, for example by dragging the
185 slider, the scrollbar notifies the associated widget that it must
186 change its view. The scrollbar makes the notification by evaluating a
187 Tcl command generated from the scrollbar's -command option. The com‐
188 mand may take any of the following forms. In each case, prefix is the
189 contents of the -command option, which usually has a form like
190 “.t”yview
191 prefix moveto fraction
193 Fraction is a real number between 0 and 1. The widget should
194 adjust its view so that the point given by fraction appears at
195 the beginning of the widget. If fraction is 0 it refers to the
196 beginning of the document. 1.0 refers to the end of the docu‐
197 ment, 0.333 refers to a point one-third of the way through the
198 document, and so on.
199 prefix scroll number units
201 The widget should adjust its view by number units. The units
202 are defined in whatever way makes sense for the widget, such as
203 characters or lines in a text widget. Number is either 1, which
204 means one unit should scroll off the top or left of the window,
205 or -1, which means that one unit should scroll off the bottom or
206 right of the window.
207 prefix scroll number pages
209 The widget should adjust its view by number pages. It is up to
210 the widget to define the meaning of a page; typically it is
211 slightly less than what fits in the window, so that there is a
212 slight overlap between the old and new views. Number is either
213 1, which means the next page should become visible, or -1, which
214 means that the previous page should become visible.
215
217 In versions of Tk before 4.0, the set and get widget commands used a
218 different form. This form is still supported for backward compatibil‐
219 ity, but it is deprecated. In the old command syntax, the set widget
220 command has the following form:
221 pathName set totalUnits windowUnits firstUnit lastUnit
223 In this form the arguments are all integers. TotalUnits gives
224 the total size of the object being displayed in the associated
225 widget. The meaning of one unit depends on the associated wid‐
226 get; for example, in a text editor widget units might corre‐
227 spond to lines of text. WindowUnits indicates the total number
228 of units that can fit in the associated window at one time.
229 FirstUnit and lastUnit give the indices of the first and last
230 units currently visible in the associated window (zero corre‐
231 sponds to the first unit of the object).
232 Under the old syntax the get widget command returns a list of four
234 integers, consisting of the totalUnits, windowUnits, firstUnit, and
235 lastUnit values from the last set widget command.
236 The commands generated by scrollbars also have a different form when
238 the old syntax is being used:
239 prefix unit
241 Unit is an integer that indicates what should appear at the top
242 or left of the associated widget's window. It has the same
243 meaning as the firstUnit and lastUnit arguments to the set wid‐
244 get command.
245 The most recent set widget command determines whether or not to use the
247 old syntax. If it is given two real arguments then the new syntax will
248 be used in the future, and if it is given four integer arguments then
249 the old syntax will be used.
250
252 Tk automatically creates class bindings for scrollbars that give them
253 the following default behavior. If the behavior is different for ver‐
254 tical and horizontal scrollbars, the horizontal behavior is described
255 in parentheses.
256 [1] Pressing button 1 over arrow1 causes the view in the associated
258 widget to shift up (left) by one unit so that the document
259 appears to move down (right) one unit. If the button is held
260 down, the action auto-repeats.
261 [2] Pressing button 1 over trough1 causes the view in the associated
263 widget to shift up (left) by one screenful so that the document
264 appears to move down (right) one screenful. If the button is
265 held down, the action auto-repeats.
266 [3] Pressing button 1 over the slider and dragging causes the view
268 to drag with the slider. If the jump option is true, then the
269 view does not drag along with the slider; it changes only when
270 the mouse button is released.
271 [4] Pressing button 1 over trough2 causes the view in the associated
273 widget to shift down (right) by one screenful so that the docu‐
274 ment appears to move up (left) one screenful. If the button is
275 held down, the action auto-repeats.
276 [5] Pressing button 1 over arrow2 causes the view in the associated
278 widget to shift down (right) by one unit so that the document
279 appears to move up (left) one unit. If the button is held down,
280 the action auto-repeats.
281 [6] If button 2 is pressed over the trough or the slider, it sets
283 the view to correspond to the mouse position; dragging the
284 mouse with button 2 down causes the view to drag with the mouse.
285 If button 2 is pressed over one of the arrows, it causes the
286 same behavior as pressing button 1.
287 [7] If button 1 is pressed with the Control key down, then if the
289 mouse is over arrow1 or trough1 the view changes to the very top
290 (left) of the document; if the mouse is over arrow2 or trough2
291 the view changes to the very bottom (right) of the document; if
292 the mouse is anywhere else then the button press has no effect.
293 [8] In vertical scrollbars the Up and Down keys have the same behav‐
295 ior as mouse clicks over arrow1 and arrow2, respectively. In
296 horizontal scrollbars these keys have no effect.
297 [9] In vertical scrollbars Control-Up and Control-Down have the same
299 behavior as mouse clicks over trough1 and trough2, respectively.
300 In horizontal scrollbars these keys have no effect.
301 [10] In horizontal scrollbars the Up and Down keys have the same
303 behavior as mouse clicks over arrow1 and arrow2, respectively.
304 In vertical scrollbars these keys have no effect.
305 [11] In horizontal scrollbars Control-Up and Control-Down have the
307 same behavior as mouse clicks over trough1 and trough2, respec‐
308 tively. In vertical scrollbars these keys have no effect.
309 [12] The Prior and Next keys have the same behavior as mouse clicks
311 over trough1 and trough2, respectively.
312 [13] The Home key adjusts the view to the top (left edge) of the doc‐
314 ument.
315 [14] The End key adjusts the view to the bottom (right edge) of the
317 document.
318
320 Create a window with a scrollable text widget:
321 toplevel .tl
322 text .tl.t -yscrollcommand {.tl.s set}
323 scrollbar .tl.s -command {.tl.t yview}
324 grid .tl.t .tl.s -sticky nsew
325 grid columnconfigure .tl 0 -weight 1
326 grid rowconfigure .tl 0 -weight 1
327
329 ttk:scrollbar(n)
330
332 scrollbar, widget
333Tk 4.1 scrollbar(n)