1Button(3) User Contributed Perl Documentation Button(3)
2
6 Tk::Button - Create and manipulate Button widgets
7
9 $button = $parent->Button(?options?);
10
12 -activebackground -activeforeground -anchor -background -bitmap -bor‐
13 derwidth -compound -cursor -disabledforeground -font -foreground -high‐
14 lightbackground -highlightcolor -highlightthickness -image -justify
15 -padx -pady -relief -repeatdelay -repeatinterval -takefocus -text
16 -textvariable -underline -wraplength
17 See Tk::options for details of the standard options.
19
21 Name: command
22 Class: Command
23 Switch: -command
24 Specifies a Perl/Tk callback to associate with the button. This
25 command is typically invoked when mouse button 1 is released over
26 the button window.
27 Command-Line Name: -compound
29 Database Name: compound
30 Database Class: Compound
31 Specifies whether the button should display both an image and text,
32 and if so, where the image should be placed relative to the text.
33 Valid values for this option are bottom, center, left, none, right
34 and top. The default value is none, meaning that the button will
35 display either an image or text, depending on the values of the
36 -image and -bitmap options.
37 Name: default
39 Class: Default
40 Switch: -default
41 Specifies one of three states for the default ring: normal, active,
42 or disabled. In active state, the button is drawn with the plat‐
43 form specific appearance for a default button. In normal state,
44 the button is drawn with the platform specific appearance for a
45 non-default button, leaving enough space to draw the default button
46 appearance. The normal and active states will result in buttons of
47 the same size. In disabled state, the button is drawn with the
48 non-default button appearance without leaving space for the default
49 appearance. The disabled state may result in a smaller button than
50 the active state. ring.
51 Name: height
53 Class: Height
54 Switch: -height
55 Specifies a desired height for the button. If an image or bitmap
56 is being displayed in the button then the value is in screen units
57 (i.e. any of the forms acceptable to Tk_GetPixels); for text it is
58 in lines of text. If this option isn't specified, the button's
59 desired height is computed from the size of the image or bitmap or
60 text being displayed in it.
61 Command-Line Name: -overrelief
63 Database Name: overRelief
64 Database Class: OverRelief
65 Specifies an alternative relief for the button, to be used when
66 the mouse cursor is over the widget. This option can be used to
67 make toolbar buttons, by configuring -relief flat -overrelief
68 raised. If the value of this option is the empty string, then no
69 alternative relief is used when the mouse cursor is over the but‐
70 ton. The empty string is the default value.
71 Name: state
73 Class: State
74 Switch: -state
75 Specifies one of three states for the button: normal, active, or
76 disabled. In normal state the button is displayed using the fore‐
77 ground and background options. The active state is typically used
78 when the pointer is over the button. In active state the button is
79 displayed using the activeForeground and activeBackground options.
80 Disabled state means that the button should be insensitive: the
81 default bindings will refuse to activate the widget and will ignore
82 mouse button presses. In this state the disabledForeground and
83 background options determine how the button is displayed.
84 Name: width
86 Class: Width
87 Switch: -width
88 Specifies a desired width for the button. If an image or bitmap is
89 being displayed in the button then the value is in screen units
90 (i.e. any of the forms acceptable to Tk_GetPixels); for text it is
91 in characters. If this option isn't specified, the button's
92 desired width is computed from the size of the image or bitmap or
93 text being displayed in it.
94
96 The Button method creates a new window (given by the $widget argument)
97 and makes it into a button widget. Additional options, described
98 above, may be specified on the command line or in the option database
99 to configure aspects of the button such as its colors, font, text, and
100 initial relief. The button command returns its $widget argument. At
101 the time this command is invoked, there must not exist a window named
102 $widget, but $widget's parent must exist.
103 A button is a widget that displays a textual string, bitmap or image.
105 If text is displayed, it must all be in a single font, but it can
106 occupy multiple lines on the screen (if it contains newlines or if
107 wrapping occurs because of the -wraplength option) and one of the char‐
108 acters may optionally be underlined using the -underline option. It
109 can display itself in either of three different ways, according to the
110 -state option; it can be made to appear raised, sunken, or flat; and it
111 can be made to flash. When a user invokes the button (by pressing
112 mouse button 1 with the cursor over the button), then the perl/Tk call‐
113 back specified in the -command option is invoked.
114
116 The Button method creates a widget object. This object supports the
117 configure and cget methods described in Tk::options which can be used
118 to enquire and modify the options described above. The widget also
119 inherits all the methods provided by the generic Tk::Widget class.
120 The following additional methods are available for button widgets:
122 $button->flash
124 Flash the button. This is accomplished by redisplaying the button
125 several times, alternating between active and normal colors. At
126 the end of the flash the button is left in the same normal/active
127 state as when the command was invoked. This command is ignored if
128 the button's state is disabled.
129 $button->invoke
131 Invoke the callback associated with the buttons -command option, if
132 there is one. The return value is the return value from the call‐
133 back, or the undefined value if there is no callback associated
134 with the button. This command is ignored if the button's state is
135 disabled.
136
138 Tk automatically creates class bindings for buttons that give them
139 default behavior:
140 [1] A button activates whenever the mouse passes over it and deacti‐
142 vates whenever the mouse leaves the button. Under Windows, this
143 binding is only active when mouse button 1 has been pressed over
144 the button.
145 [2] A button's relief is changed to sunken whenever mouse button 1 is
147 pressed over the button, and the relief is restored to its original
148 value when button 1 is later released.
149 [3] If mouse button 1 is pressed over a button and later released over
151 the button, the button is invoked. However, if the mouse is not
152 over the button when button 1 is released, then no invocation
153 occurs.
154 [4] When a button has the input focus, the space key causes the button
156 to be invoked.
157 If the button's state is disabled then none of the above actions
159 occur: the button is completely non-responsive.
160 The behavior of buttons can be changed by defining new bindings for
162 individual widgets or by redefining the class bindings.
163
165 button, widget
166perl v5.8.8 2008-02-05 Button(3)