<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<HTML>
<HEAD>
<TITLE>Programming in XPCE/Prolog: Section 11.3</TITLE><LINK REL=home HREF="index.html">
<LINK REL=contents HREF="Contents.html">
<LINK REL=index HREF="DocIndex.html">
<LINK REL=summary HREF="summary.html">
<LINK REL=previous HREF="balloon.html">
<LINK REL=next HREF="toc.html">
<STYLE type="text/css">
/* Style sheet for SWI-Prolog latex2html
*/
dd.defbody
{ margin-bottom: 1em;
}
dt.pubdef
{ background-color: #c5e1ff;
}
pre.code
{ margin-left: 1.5em;
margin-right: 1.5em;
border: 1px dotted;
padding-top: 5px;
padding-left: 5px;
padding-bottom: 5px;
background-color: #f8f8f8;
}
div.navigate
{ text-align: center;
background-color: #f0f0f0;
border: 1px dotted;
padding: 5px;
}
div.title
{ text-align: center;
padding-bottom: 1em;
font-size: 200%;
font-weight: bold;
}
div.author
{ text-align: center;
font-style: italic;
}
div.abstract
{ margin-top: 2em;
background-color: #f0f0f0;
border: 1px dotted;
padding: 5px;
margin-left: 10%; margin-right:10%;
}
div.abstract-title
{ text-align: center;
padding: 5px;
font-size: 120%;
font-weight: bold;
}
div.toc-h1
{ font-size: 200%;
font-weight: bold;
}
div.toc-h2
{ font-size: 120%;
font-weight: bold;
margin-left: 2em;
}
div.toc-h3
{ font-size: 100%;
font-weight: bold;
margin-left: 4em;
}
div.toc-h4
{ font-size: 100%;
margin-left: 6em;
}
span.sec-nr
{
}
span.sec-title
{
}
span.pred-ext
{ font-weight: bold;
}
/* Footnotes */
sup.fn { color: blue; text-decoration: underline; }
span.fn-text: { display: none; }
sup.fn span {display: none;}
sup:hover span
{ display: block !important;
position: absolute; top: auto; left: auto; width: 80%;
color: #000; background: white;
border: 2px solid;
padding: 5px; margin: 10px; z-index: 100;
font-size: smaller;
}
</STYLE>
</HEAD>
<BODY BGCOLOR="white">
<DIV class="navigate"><A class="nav" href="index.html"><IMG SRC="home.gif" BORDER=0 ALT="Home"></A>
<A class="nav" href="Contents.html"><IMG SRC="index.gif" BORDER=0 ALT="Contents"></A>
<A class="nav" href="DocIndex.html"><IMG SRC="yellow_pages.gif" BORDER=0 ALT="Index"></A>
<A class="nav" href="summary.html"><IMG SRC="info.gif" BORDER=0 ALT="Summary"></A>
<A class="nav" href="balloon.html"><IMG SRC="prev.gif" BORDER=0 ALT="Previous"></A>
<A class="nav" href="toc.html"><IMG SRC="next.gif" BORDER=0 ALT="Next"></A>
</DIV>
<H2><A NAME="sec:11.3"><SPAN class="sec-nr">11.3</SPAN> <SPAN class="sec-title">Dialog
support libraries</SPAN></A></H2>
<A NAME="sec:libdia"></A>
<P>This section deals with a number of classes from the library to
simplify the creation of dialog windows.
<H3><A NAME="sec:11.3.1"><SPAN class="sec-nr">11.3.1</SPAN> <SPAN class="sec-title">Reporting
errors and warnings</SPAN></A></H3>
<P><A NAME="idx:messagesreporting:484"></A><A NAME="idx:errorsreporting:485"></A><A NAME="idx:reporting:486"></A>Error,
and warning and informational messages are raised using the
<B><CODE>-></CODE>report</B> or <B><CODE>-></CODE>error</B> method
defined on all <font size=-1>XPCE</font> objects. Basic error and
message handling is described in <A class="sec" href="errors.html">section
10.8</A>. The library
<CODE>library(pce_report)</CODE> defines the classes <B>reporter</B> and
<B>report_dialog</B>.
<P>
<UL>
<LI><I><B>reporter</B></I><BR>
This is a refinement of class <A class="" href="summary.html#class:label">label</A>,
displayed using the fashionable lowered 3D-style. In addition, it
redefines the <B><CODE>-></CODE>report</B> message to colour error
messages red.
<P>
<LI><I><B>report_dialog</B></I><BR>
This is a trivial subclass of <A class="" href="summary.html#class:dialog">dialog</A>,
displaying a
<B>reporter</B> and constraining this reporter to occupy the entire
window.
</UL>
<P>An example using these classes is in <A class="sec" href="libdia.html">section
11.3.2</A>.
<H3><A NAME="sec:11.3.2"><SPAN class="sec-nr">11.3.2</SPAN> <SPAN class="sec-title">Toolbar
support</SPAN></A></H3>
<A NAME="sec:toolbar"></A>
<P><A NAME="idx:buttonbar:487"></A>The library <CODE>library(toolbar)</CODE>
defines the classes <B>tool_bar</B>,
<B>tool_button</B> and <B>tool_status_button</B> to simplify the
definition of tool-bars.
<DL>
<DT><STRONG>tool_bar ->initialise:</STRONG> <VAR>Client:object*,
Orientation:[{horizontal,vertical}]</VAR></DT>
<DD class="defbody">
Create a <B>tool_bar</B> for which the buttons execute actions on
<VAR>Client</VAR> (see class <B>tool_button</B> for details). By default
the buttons are placed left-to-right, but using <CODE>vertical</CODE>
<VAR>Orientation</VAR> they can be stacked top-to-bottom.</DD>
<DT><STRONG>tool_bar ->append:</STRONG> <VAR>Button:tool_button<TT>|</TT>{gap}</VAR></DT>
<DD class="defbody">
Append a tool-button to the bar or, using the name <CODE>gap</CODE>,
make a small gap to separate logical groups of buttons.</DD>
<DT><STRONG>tool_bar ->activate:</STRONG> <VAR></VAR></DT>
<DD class="defbody">
Send <B><CODE>-></CODE>activate</B> to all member buttons, reflecting
whether they are ready to accept commands or `grayed-out'.</DD>
<DT><STRONG>tool_button ->initialise:</STRONG> <VAR></VAR></DT>
<DD class="defbody">
Define a button for <A NAME="idx:toolbarsendappend:488"></A>`<B>tool_bar<CODE>-></CODE>append</B>'. <VAR>Action</VAR>
is the action to execute. If this is a plain atom, this method without
arguments is invoked on the <A NAME="idx:toolbargetclient:489"></A>`<B>tool_bar<CODE><-</CODE>client</B>'.
If it is a code object this code is simply executed. <VAR>Label</VAR> is
the label. Normally for toolbars this will be an <A class="" href="summary.html#class:image">image</A>
object. <VAR>Balloon</VAR> defines the text for the popup-window if the
user rests the pointer long enough on the button. It it is a name, this
balloon is subject to
<A NAME="idx:namegetlabelname:490"></A>`<B>name<CODE><-</CODE>label_name</B>'
(see <A class="sec" href="mlingual.html">section 11.7</A>), otherwise it
is passed literally. Finally, if <VAR>Condition</VAR> is present it is
evaluated by
<B><CODE>-></CODE>activate</B> to determine the activation-state of
the button.</DD>
<DT><STRONG>tool_button ->activate:</STRONG> <VAR></VAR></DT>
<DD class="defbody">
If <B><CODE><-</CODE>condition</B> is present, evaluate it and send <B><CODE>-></CODE>active</B>.</DD>
<DT><STRONG>tool_button ->active:</STRONG> <VAR>Active:bool</VAR></DT>
<DD class="defbody">
If <A NAME="idx:off:491"></A><B>@off</B>, deactivate the button and
provide visual feedback for this.
</DD>
</DL>
<P>A <B>tool_status_button</B> is toggled between depressed state and
normal state on each click. If it has an atomic <B><CODE><-</CODE>action</B>
it will send <VAR>action</VAR>: <A NAME="idx:on:492"></A><B>@on</B> to
the client when going to depressed state and <VAR>action</VAR>:<A NAME="idx:off:493"></A><B>@off</B>
when returning to normal state. If the <B><CODE><-</CODE>action</B>
is a code object this boolean will for forwarded over the code object.
See <A class="sec" href="exeobjects.html">section 10.2</A>.
<H3><A NAME="sec:11.3.3"><SPAN class="sec-nr">11.3.3</SPAN> <SPAN class="sec-title">Example</SPAN></A></H3>
<P>The example below uses these classes as well as class <A class="" href="summary.html#class:menu_bar">menu_bar</A>
to arrive at a typical modern application layout.
<P><A NAME="fig:libdia"></A>
<CENTER>
<IMG SRC="libdia.gif">
</CENTER>
<TABLE ALIGN=center WIDTH="75%"><TR><TD>
<B>Figure 20 : </B>Simple application framework</TABLE>
<PRE class="code">
% Pull in the classes
:- pce_autoload(report_dialog, library(pce_report)).
:- pce_autoload(tool_bar, library(toolbar)).
:- pce_autoload(finder, library(find_file)).
:- pce_global(@finder, new(finder)).
% Define icons as program resources
resource(printer, image, image('16x16/print.xpm')).
resource(floppy, image, image('16x16/save.xpm')).
% Define the application as a subclass of frame.
:- pce_begin_class(myapp, frame,
"Frame representing the application").
initialise(MyApp) :->
send_super(MyApp, initialise, 'My application'),
send(MyApp, append, new(D, dialog)),
send(D, pen, 0),
send(D, gap, size(5, 5)),
send(D, append, new(menu_bar)),
send(D, append, new(tool_bar(MyApp))),
send(MyApp, fill_menu_bar),
send(MyApp, fill_tool_bar),
send(new(W, myapp_workspace), below, D),
send(new(report_dialog), below, W).
fill_menu_bar(F) :->
get(F, member, dialog, D),
get(D, member, menu_bar, MB),
send_list(MB, append,
[ new(File, popup(file)),
new(_Edit, popup(edit))
]),
send_list(File, append,
[ menu_item(load,
message(F, load),
end_group := @on),
menu_item(print,
message(F, print))
]).
fill_tool_bar(F) :->
get(F, member, dialog, D),
get(D, member, tool_bar, TB),
send_list(TB, append,
[ tool_button(load,
resource(floppy),
load),
gap, % skip a little
tool_button(print,
resource(printer),
print)
]).
print(MyApp) :->
"Print the document"::
send(MyApp, report, progress, 'Printing ...'),
get(MyApp, member, myapp_workspace, WS),
send(WS, print),
send(MyApp, report, progress, done).
load(MyApp) :->
"Ask a file and load it"::
get(@finder, file, @on, myp, File),
get(MyApp, member, myapp_workspace, WS),
send(WS, load, File).
:- pce_end_class(myapp).
% dummy class for the work-area of your application
:- pce_begin_class(myapp_workspace, window).
:- pce_end_class(myapp_workspace).</PRE>
<P></BODY></HTML>
