This section discusses a few remaining minor widgets. These are widgets which are useful, but have a single function. They are simple widgets much like the ones already discussed. These are grouped together in a single section because they are similar in complexity and functionality to widgets discussed previously.
The label widget does exactly what you would expect; it is used to insert a short text string into the interface. Here is a simple example:
f := frame(f,side='left')
l := label(f,'Options:')
b1 := button(f,'continue')
b2 := button(f,'quit')
whenever b2->press do
exit
This dialog is shown in Figure 10.7.
The label is simply placed in the frame first, and then the buttons which it describes are added to the frame. Table 10.8 show the other parameters which can be specified during the creation of a label.
Parameter Default Values Description parent F widget parent of the label text 'label' string label text justify 'left' 'center' 'left' 'right' justification of text padx 4 dimension horizontal padding pady 2 dimension vertical padding font '' X font text font width 0 integer width in character units relief 'flat' 'flat' 'ridge' 'raised' 'sunken' 'groove' border relief borderwidth 2 dimension border width foreground 'black' X color color of text background 'lightgrey' X color background color fill 'none' 'x' 'y' 'both' 'none' how to expand when resized
Table 10.9 shows the events which labels accept, and as you can
Event I/O Values Description background 
X color change background color bind <X> <G> associate Xevent <X> with Glish event <G> borderwidth dimension change border width font X font set text font foreground X color change foreground color justify 'center' 'left' 'right' set text justification padx dimension set horizontal padding pady dimension set vertical padding relief 'flat' 'ridge' 'raised' 'sunken' 'groove' change border relief text string set label text width integer set width (in character units)
see from the table, labels do not generate any events.
The scale widget allows the user to pick a number out of a range. In other toolkits, this has been called a slider. Here is an example of the creation of a scale:
f := frame(side='left')
v := scale(f,0,110,text='Volume')
t := scale(f,0,110,text='Treble')
b := scale(f,0,110,text='Bass')
The interface which this example creates is shown in Figure 10.8.
The value of the slider is posted with the value event. Here is an example,
whenever v->value do
print "Volume:",$value
This whenever will print out a message each time the volume is changed. Note
however if you just want to get the last value of the slider, it is accessible as
a member of the agent, in this case v.value. This is because the last
value of each event name is retained in the agent. As a result, whenever
statements are often not needed with scales. Table 10.10 lists the
other construction parameters for scales, and Table 10.11 lists
the scale events.
Parameter Default Values Description parent widget parent of the scale start 0 integer starting integer for scale end 100 integer ending integer for scale length 110 integer length of scale text '' string optional label for scale resolution 1 float resolution of the scale orient 'horizontal' 'horizontal' 'vertical orientation of scale width '15' width/height of the thumb font '' X font text font relief 'flat' 'flat' 'ridge' 'raised' 'sunken' 'groove' edge relief borderwidth 2 dimension border width foreground 'black' X color color of text background 'lightgrey' X color background color fill '' 'x' 'y' 'both' 'none' how to expand when resized; default: expand with orient
Event I/O Values Description background X color change background color bind <X> <G> associate Xevent <X> with Glish event <G> borderwidth dimension change border width end integer change ending value font X font set text font foreground X color change foreground color length integer change length of scale orient 'horizontal' 'vertical change orientation relief 'flat' 'ridge' 'raised' 'sunken' 'groove' change border relief resolution float change resolution of scale start integer change starting value text string set scale label value 
integer value changed by user width integer change width/height of scale
The message widget can be viewed as a multi-line label. It is essentially a scratch pad for displaying several word messages to the user. For long messages, the text widget is a better choice.
Here is an example of the message widget in use:
f := frame(side='left')
b := button(f,'time')
m := message(f,shell('date'))
whenever b->press do
m->text(shell('date'))
This simple example updates the time display in the message widget whenever
the button is pressed. This would look like Figure 10.9.
In general, the text event is the primary event for the message widget. The other construction parameters are shown on Table 10.12. The message widget itself does not generate any event, but the events which it accepts are shown in Table 10.13.
Parameter Default Values Description parent widget parent of the message text 'message' string text for message width 180 dimension width of message justify 'center' 'center' 'left' 'right' justification of text font '' X font font of text padx 7 dimension horizontal padding pady 3 dimension vertical padding relief 'raised' 'flat' 'ridge' 'raised' 'sunken' 'groove' edge relief borderwidth 2 dimension border width foreground 'black' X color color of text background 'lightgrey' X color background color fill 'none' 'x' 'y' 'both' 'none' how to expand when resized
Event I/O Values Description background X color change background color bind <X> <G> associate Xevent <X> with Glish event <G> borderwidth dimension change border width font X font set font for text foreground X color change foreground color justify 'center' 'left' 'right' set justification for text padx dimension set horizontal padding around text pady dimension set vertical padding around text relief 'flat' 'ridge' 'raised' 'sunken' 'groove' change border relief text string set text width integer set width (in character units)
The entry provides slots where the user can type in text. The script can then retrieve this text when it is needed. Here is a more complex example:
f := frame()
ef := frame(f,side='left')
b := button(ef,'ls')
en := entry(ef)
lbf := frame(f,side='left') # **
lb := listbox(lbf,width=32) # **
sb := scrollbar(lbf) # **
whenever b->press, en->return do
{
lb->delete("start","end")
dir := en->get()
files := shell('if [ -r',dir,'];then ls -1F',dir,';else exit 1;fi')
if ( ! files::status )
lb->insert(files)
else
en->insert('*BAD DIRECTORY* ','start')
}
whenever sb->scroll do # **
lb->view($value) # **
whenever lb->yscroll do # **
sb->view($value) # **
In this example, first note that the lines tagged with ** are nearly
identical to the listbox plus scrollbar example in
§ 10.4.2. The remaining lines setup a button and an entry
widget. Next the listbox plus scrollbar dialog from the
previous example is used. In this dialog, the user will enter a directory in the
entry widget, and the contents of the directory will show up in the
listbox (see Figure 10.10).
The mechanics of this are controlled by the first
whenever. Whenever the user presses the button or hits the
<return> key in the entry widget, the listbox is cleared, the string
from the entry widget is retrieved, an ls is done on the directory, and if it
succeeds, the output is used to fill the listbox otherwise an error is
indicated in the entry widget. The complicated shell() command which
actually does the ls just checks to see if the directory exists, and if
it does exist, the ls is done, otherwise the shell command exits with a
non-zero status.
This example shows three of the entry widget events, get,
insert, and return. get simply returns the contents of the
entry widget. insert is used to insert text into the entry widget.
The second parameter to insert is optional, and it specifies where to
insert the string. By default, the string is inserted at the end. The return
event is generated when the user hits the <return> key in the entry
widget. Table 10.14 list all of the parameters to entry(), and
Table 10.15 lists the entry widget events.
Parameter Default Values Description parent widget parent of the entry width 0 integer width in character units justify 'center' 'center' 'left' 'right' justification of text font '' X font font of text relief 'raised' 'flat' 'ridge' 'raised' 'sunken' 'groove' edge relief borderwidth 2 dimension border width foreground 'black' X color color of text background 'lightgrey' X color background color disabled F boolean is inactivated? show T boolean show typed characters? exportselection F boolean export to X clipboard? fill 'x 'x' 'y' 'both' 'none' how to expand when resized
Event I/O Values Description background X color change background color bind <X> <G> associate Xevent <X> with Glish event <G> borderwidth dimension change border width delete string delete indicated character, use 2 strings to delete range disable disable widget, must be balanced by enable disabled boolean set state, disable (T) or enable (F) enable enable widget, must be balanced by disable exportselection boolean export selection to X clipboard? font X font change text font foreground X color change foreground color get 
get current contents insert string insert item, optional 2nd param insert index justify 'center' 'left' 'right' set justification for text relief 'flat' 'ridge' 'raised' 'sunken' 'groove' change border relief return string generated when user hits return, returns contents show boolean show typed characters? view record scrollbar update event width integer entry width in character units xscroll double information for horizontal scrollbar update
Notice in Table 10.15 that the entry widget generates the events necessary to connect a horizontal scrollbar to the entry widget. This is done in a way analogous to connecting a vertical scrollbar to the listbox, i.e. change yscroll to xscroll.
