1button(n) Tk Built-In Commands button(n)
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6
8 button - Create and manipulate button widgets
9
11 button pathName ?options?
12
14 -activebackground -font -relief
15 -activeforeground -foreground -repeatdelay
16 -anchor -highlightbackground -repeatinterval
17 -background -highlightcolor -takefocus
18 -bitmap -highlightthickness -text
19 -borderwidth -image -textvariable
20 -compound -justify -underline
21 -cursor -padx -wraplength
22 -disabledforeground -pady
23 See the options manual entry for details on the standard options.
25
27 [-command command] Specifies a Tcl command to associate with the but‐
28 ton. This command is typically invoked when mouse button 1 is released
29 over the button window. [-default default] Specifies one of three │
30 states for the default ring: normal, active, or disabled. In active │
31 state, the button is drawn with the platform specific appearance for a │
32 default button. In normal state, the button is drawn with the platform │
33 specific appearance for a non-default button, leaving enough space to │
34 draw the default button appearance. The normal and active states will │
35 result in buttons of the same size. In disabled state, the button is │
36 drawn with the non-default button appearance without leaving space for │
37 the default appearance. The disabled state may result in a smaller │
38 button than the active state. [-height height] Specifies a desired
39 height for the button. If an image or bitmap is being displayed in the
40 button then the value is in screen units (i.e. any of the forms accept‐
41 able to Tk_GetPixels); for text it is in lines of text. If this option
42 isn't specified, the button's desired height is computed from the size
43 of the image or bitmap or text being displayed in it. [-overre‐ │
44 lief overRelief] Specifies an alternative relief for the button, to be │
45 used when the mouse cursor is over the widget. This option can be used │
46 to make toolbar buttons, by configuring -relief flat -overrelief │
47 raised. If the value of this option is the empty string, then no │
48 alternative relief is used when the mouse cursor is over the button. │
49 The empty string is the default value. [-state state] Specifies one of
50 three states for the button: normal, active, or disabled. In normal
51 state the button is displayed using the foreground and background
52 options. The active state is typically used when the pointer is over
53 the button. In active state the button is displayed using the active‐
54 Foreground and activeBackground options. Disabled state means that the
55 button should be insensitive: the default bindings will refuse to
56 activate the widget and will ignore mouse button presses. In this
57 state the disabledForeground and background options determine how the
58 button is displayed. [-width width] Specifies a desired width for the
59 button. If an image or bitmap is being displayed in the button then
60 the value is in screen units (i.e. any of the forms acceptable to
61 Tk_GetPixels); for text it is in characters. If this option isn't
62 specified, the button's desired width is computed from the size of the
63 image or bitmap or text being displayed in it.
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65
68 The button command creates a new window (given by the pathName argu‐
69 ment) and makes it into a button widget. Additional options, described
70 above, may be specified on the command line or in the option database
71 to configure aspects of the button such as its colors, font, text, and
72 initial relief. The button command returns its pathName argument. At
73 the time this command is invoked, there must not exist a window named
74 pathName, but pathName's parent must exist.
75 A button is a widget that displays a textual string, bitmap or image.
77 If text is displayed, it must all be in a single font, but it can
78 occupy multiple lines on the screen (if it contains newlines or if
79 wrapping occurs because of the wrapLength option) and one of the char‐
80 acters may optionally be underlined using the underline option. It can
81 display itself in either of three different ways, according to the
82 state option; it can be made to appear raised, sunken, or flat; and it
83 can be made to flash. When a user invokes the button (by pressing
84 mouse button 1 with the cursor over the button), then the Tcl command
85 specified in the -command option is invoked.
86
89 The button command creates a new Tcl command whose name is pathName.
90 This command may be used to invoke various operations on the widget.
91 It has the following general form:
92 pathName option ?arg arg ...?
93 Option and the args determine the exact behavior of the command. The
94 following commands are possible for button widgets:
95 pathName cget option
97 Returns the current value of the configuration option given by
98 option. Option may have any of the values accepted by the but‐
99 ton command.
100 pathName configure ?option? ?value option value ...?
102 Query or modify the configuration options of the widget. If no
103 option is specified, returns a list describing all of the avail‐
104 able options for pathName (see Tk_ConfigureInfo for information
105 on the format of this list). If option is specified with no
106 value, then the command returns a list describing the one named
107 option (this list will be identical to the corresponding sublist
108 of the value returned if no option is specified). If one or
109 more option-value pairs are specified, then the command modifies
110 the given widget option(s) to have the given value(s); in this
111 case the command returns an empty string. Option may have any
112 of the values accepted by the button command.
113 pathName flash
115 Flash the button. This is accomplished by redisplaying the but‐
116 ton several times, alternating between active and normal colors.
117 At the end of the flash the button is left in the same nor‐
118 mal/active state as when the command was invoked. This command
119 is ignored if the button's state is disabled.
120 pathName invoke
122 Invoke the Tcl command associated with the button, if there is
123 one. The return value is the return value from the Tcl command,
124 or an empty string if there is no command associated with the
125 button. This command is ignored if the button's state is dis‐
126 abled.
127
130 Tk automatically creates class bindings for buttons that give them
131 default behavior:
132 [1] A button activates whenever the mouse passes over it and deacti‐
134 vates whenever the mouse leaves the button. Under Windows, this │
135 binding is only active when mouse button 1 has been pressed over │
136 the button.
137 [2] A button's relief is changed to sunken whenever mouse button 1
139 is pressed over the button, and the relief is restored to its
140 original value when button 1 is later released.
141 [3] If mouse button 1 is pressed over a button and later released
143 over the button, the button is invoked. However, if the mouse
144 is not over the button when button 1 is released, then no invo‐
145 cation occurs.
146 [4] When a button has the input focus, the space key causes the but‐
148 ton to be invoked.
149 If the button's state is disabled then none of the above actions occur:
151 the button is completely non-responsive.
152 The behavior of buttons can be changed by defining new bindings for
154 individual widgets or by redefining the class bindings.
155
158 button, widget
159Tk 4.4 button(n)