1Balloon(3) User Contributed Perl Documentation Balloon(3)
2
6 Tk::Balloon - pop up help balloons.
7
9 use Tk::Balloon;
10 ...
11 $b = $top->Balloon(-statusbar => $status_bar_widget);
12 # Normal Balloon:
14 $b->attach($widget,
15 -balloonmsg => "Balloon help message",
16 -statusmsg => "Status bar message");
17 # Balloon attached to entries in a menu widget:
19 $b->attach($menu, -state => 'status',
20 -msg => ['first menu entry',
21 'second menu entry',
22 ...
23 ],
24 );
25 # Balloon attached to individual items in a canvas widget:
27 $b->attach($canvas, -balloonposition => 'mouse',
28 -msg => {'item1' => 'msg1',
29 'tag2' => 'msg2',
30 ...
31 },
32 );
33 # Balloon attached to items in a listbox widget:
35 $b->attach($listbox, -balloonposition => 'mouse',
36 -msg => ['first listbox element',
37 '2nd listbox element',
38 ...
39 ],
40 );
41
43 Balloon provides the framework to create and attach help balloons to
44 various widgets so that when the mouse pauses over the widget for more
45 than a specified amount of time, a help balloon is popped up.
46 Balloons and Menus or Listboxes
48 If the balloon is attached to a Menu or Listbox widget and the message
49 arguments are array references, then each element in the array will be
50 the message corresponding to a menu entry or listbox element. The
51 balloon message will then be shown for the entry which the mouse pauses
52 over. Otherwise it is assumed that the balloon is to be attached to the
53 Menu or Listbox as a whole. You can have separate status and balloon
54 messages just like normal balloons.
55 Balloons and Canvases
57 If the balloon is attached to a Canvas widget and the message arguments
58 are hash references, then each hash key should correspond to a canvas
59 item ID or tag and the associated value will correspond to the message
60 for that canvas item. The balloon message will then be shown for the
61 current item (the one at the position of the mouse). Otherwise it is
62 assumed that the balloon is to be attached to the Canvas as a whole.
63 You can have separate status and balloon messages just like normal
64 balloons.
65 Balloons and HLists
67 If the balloon is attached to a HList widget and the message arguments
68 are hash references, then each hash key should correspond to a HList
69 path and the associated value will correspond to the message for that
70 HList item. The balloon message will then be shown for the current item
71 (the one at the position of the mouse). Otherwise it is assumed that
72 the balloon is to be attached to the HList as a whole. You can have
73 separate status and balloon messages just like normal balloons.
74 Balloon Position
76 By default, the balloon pops up at the lower right side of the client.
77 If it would extend outside the lower screen border, its positioned at
78 the upper right side. If it would extend outside the right screen
79 border it's shown on the lower left side of the client. If it would
80 extend outside both the lower and the right screen border, it's
81 positioned at the upper left side of the client. Thus, the little arrow
82 always points to the attached client.
83
85 Balloon accepts all of the options that the Frame widget accepts. In
86 addition, the following options are also recognized.
87 -initwait
89 Specifies the amount of time to wait without activity before
90 popping up a help balloon. Specified in milliseconds. Defaults to
91 350 milliseconds. This applies to both the popped up balloon and
92 the status bar message.
93 -state
95 Can be one of 'balloon', 'status', 'both' or 'none' indicating that
96 the help balloon, status bar help, both or none respectively should
97 be activated when the mouse pauses over the client widget. Default
98 is 'both'.
99 -statusbar
101 Specifies the widget used to display the status message. This
102 widget should accept the -text option and is typically a Label. If
103 the widget accepts the -textvariable option and that option is
104 defined then it is used instead of the -text option.
105 -balloonposition
107 Can be one of 'widget' or 'mouse'. It controls where the balloon
108 will popup. 'widget' makes the balloon appear at the lower right
109 corner of the widget it is attached to (default), and 'mouse' makes
110 the balloon appear below and to the right of the current mouse
111 position.
112 -postcommand
114 This option takes a CODE reference which will be executed before
115 the balloon and statusbar messages are displayed and should return
116 a true or false value to indicate whether you want the balloon to
117 be displayed or not. This also lets you control where the balloon
118 is positioned by returning a true value that looks like X,Y
119 (matches this regular expression: "/^(\d+),(\d+)$/"). If the
120 postcommand returns a value that matches that re then those
121 coordinates will be used as the position to post the balloon.
122 Warning: this subroutine should return quickly or the balloon
123 response will appear slow.
124 -cancelcommand
126 This option takes a CODE reference which will be executed before
127 the balloon and statusbar messages are canceled and should return a
128 true or false value to indicate whether you want the balloon to be
129 canceled or not. Warning: this subroutine should return quickly or
130 the balloon response will appear slow.
131 -motioncommand
133 This option takes a CODE reference which will be executed for any
134 motion event and should return a true or false value to indicate
135 whether the currently displayed balloon should be canceled
136 (deactivated). If it returns true then the balloon will definitely
137 be canceled, if it returns false then it may still be canceled
138 depending the internal rules. Note: a new balloon may be posted
139 after the -initwait time interval, use the -postcommand option to
140 control that behavior. Warning: the subroutine should be extremely
141 fast or the balloon response will appear slow and consume a lot of
142 CPU time (it is executed every time the mouse moves over the
143 widgets the balloon is attached to).
144 -numscreens
146 This option accepts an integer 1 or greater. This option should be
147 used to avoid disjointed balloons across multiple screens in single
148 logical sceen (SLS) mode. This only currently works in the
149 horizontal direction. Example: If you are running dual screens in
150 SLS mode then you would set this value to 2. Default value is 1.
151
153 The Balloon widget supports only three non-standard methods:
154 attach(widget, options)
156 Attaches the widget indicated by widget to the help system. The allowed
157 options are:
158 -statusmsg
160 The argument is the message to be shown on the status bar when the
161 mouse pauses over this client. If this is not specified, but -msg
162 is specified then the message displayed on the status bar is the
163 same as the argument for -msg. If you give it a scalar reference
164 then it is dereferenced before being displayed. Useful if the
165 postcommand is used to change the message.
166 -balloonmsg
168 The argument is the message to be displayed in the balloon that
169 will be popped up when the mouse pauses over this client. As with
170 -statusmsg if this is not specified, then it takes its value from
171 the -msg specification if any. If neither -balloonmsg nor -msg are
172 specified, or they are the empty string then no balloon is popped
173 up instead of an empty balloon. If you give it a scalar reference
174 then it is dereferenced before being displayed. Useful if the
175 postcommand is used to change the message.
176 -msg
178 The catch-all for -statusmsg and -balloonmsg. This is a convenient
179 way of specifying the same message to be displayed in both the
180 balloon and the status bar for the client.
181 -initwait
183 -state
184 -statusbar
185 -balloonposition
186 -postcommand
187 -cancelcommand
188 -motioncommand
189 These options allow you to override the balloon's default value for
190 those option for some of the widgets it is attached to. It accepts
191 the same values as above and will default to the Balloon's value.
192 detach(widget)
194 Detaches the specified widget from the help system.
195 destroy
197 Destroys the specified balloon.
198
200 The balloon label is advertised as "message".
201
203 See the balloon demo included with the widget demo script that came
204 with the distribution for examples on various ways to use balloons.
205
207 Because of the overhead associated with each balloon you create (from
208 tracking the mouse movement to know when to activate and deactivate
209 them) you will see the best performance (low CPU consumption) if you
210 create as few balloons as possible and attach them to as many widgets
211 as you can. In other words, don't create a balloon for each widget you
212 want to attach one to.
213
215 Pressing any button will deactivate (cancel) the current balloon, if
216 one exists. You can usually make the balloon reappear by moving the
217 mouse a little. Creative use of the 3 command options can help you out
218 also. If the mouse is over the balloon when a menu is unposted then the
219 balloon will remain until you move off of it.
220
222 If using balloons attached to listbox entries or canvas items in a
223 scrolled widget, then the subwidget have to be used:
224 $balloon->attach($w->Subwidget("scrolled"), -msg => ...);
226
228 Rajappa Iyer <rsi@earthling.net> did the original coding.
229 Jason A. Smith <smithj4@rpi.edu> added support for menus and made some
231 other enhancements.
232 Slaven Rezic <srezic@cpan.org> added support for canvas items.
234 Gerhard Petrowitsch <gerhard@petrowitsch.de> added intelligent
236 positioning
237 Jack Dunnigan <dunniganj@cpan.org> Made positioning more intelligent
239 and added support for multiple monitors under single logical screen.
240
242 The code and documentation was derived from Balloon.tcl from the Tix4.0
243 distribution by Ioi Lam and modified by the above mentioned authors.
244 This code may be redistributed under the same terms as Perl.
245perl v5.28.1 2019-02-12 Balloon(3)