1Button(3) User Contributed Perl Documentation Button(3)
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6 Tk::Button - Create and manipulate Button widgets
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9 $button = $parent->Button(?options?);
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12 -activebackground -activeforeground -anchor -background -bitmap
13 -borderwidth -compound -cursor -disabledforeground -font -foreground
14 -highlightbackground -highlightcolor -highlightthickness -image
15 -justify -padx -pady -relief -repeatdelay -repeatinterval -takefocus
16 -text -textvariable -underline -wraplength
17 See Tk::options for details of the standard options.
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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
43 platform specific appearance for a default button. In normal
44 state, the button is drawn with the platform specific appearance
45 for a non-default button, leaving enough space to draw the default
46 button appearance. The normal and active states will result in
47 buttons of the same size. In disabled state, the button is drawn
48 with the non-default button appearance without leaving space for
49 the default appearance. The disabled state may result in a smaller
50 button than 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
70 button. 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
77 foreground and background options. The active state is typically
78 used when the pointer is over the button. In active state the
79 button is displayed using the activeForeground and activeBackground
80 options. Disabled state means that the button should be
81 insensitive: the default bindings will refuse to activate the
82 widget and will ignore mouse button presses. In this state the
83 disabledForeground and background options determine how the button
84 is displayed.
85 Name: width
87 Class: Width
88 Switch: -width
89 Specifies a desired width for the button. If an image or bitmap is
90 being displayed in the button then the value is in screen units
91 (i.e. any of the forms acceptable to Tk_GetPixels); for text it is
92 in characters. If this option isn't specified, the button's
93 desired width is computed from the size of the image or bitmap or
94 text being displayed in it.
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97 The Button method creates a new window (given by the $widget argument)
98 and makes it into a button widget. Additional options, described
99 above, may be specified on the command line or in the option database
100 to configure aspects of the button such as its colors, font, text, and
101 initial relief. The button command returns its $widget argument. At
102 the time this command is invoked, there must not exist a window named
103 $widget, but $widget's parent must exist.
104 A button is a widget that displays a textual string, bitmap or image.
106 If text is displayed, it must all be in a single font, but it can
107 occupy multiple lines on the screen (if it contains newlines or if
108 wrapping occurs because of the -wraplength option) and one of the
109 characters may optionally be underlined using the -underline option.
110 It can display itself in either of three different ways, according to
111 the -state option; it can be made to appear raised, sunken, or flat;
112 and it can be made to flash. When a user invokes the button (by
113 pressing mouse button 1 with the cursor over the button), then the
114 perl/Tk callback specified in the -command option is invoked.
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117 The Button method creates a widget object. This object supports the
118 configure and cget methods described in Tk::options which can be used
119 to enquire and modify the options described above. The widget also
120 inherits all the methods provided by the generic Tk::Widget class.
121 The following additional methods are available for button widgets:
123 $button->flash
125 Flash the button. This is accomplished by redisplaying the button
126 several times, alternating between active and normal colors. At
127 the end of the flash the button is left in the same normal/active
128 state as when the command was invoked. This command is ignored if
129 the button's state is disabled.
130 $button->invoke
132 Invoke the callback associated with the buttons -command option, if
133 there is one. The return value is the return value from the
134 callback, or the undefined value if there is no callback associated
135 with the button. This command is ignored if the button's state is
136 disabled.
137
139 Tk automatically creates class bindings for buttons that give them
140 default behavior:
141 [1] A button activates whenever the mouse passes over it and
143 deactivates whenever the mouse leaves the button. Under Windows,
144 this binding is only active when mouse button 1 has been pressed
145 over the button.
146 [2] A button's relief is changed to sunken whenever mouse button 1 is
148 pressed over the button, and the relief is restored to its original
149 value when button 1 is later released.
150 [3] If mouse button 1 is pressed over a button and later released over
152 the button, the button is invoked. However, if the mouse is not
153 over the button when button 1 is released, then no invocation
154 occurs.
155 [4] When a button has the input focus, the space key causes the button
157 to be invoked.
158 If the button's state is disabled then none of the above actions
160 occur: the button is completely non-responsive.
161 The behavior of buttons can be changed by defining new bindings for
163 individual widgets or by redefining the class bindings.
164
166 button, widget
167perl v5.30.1 2020-01-30 Button(3)