<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<title>ComboBox with an Entry</title>
<link rel="stylesheet" type="text/css" href="style.css">
<meta name="generator" content="DocBook XSL Stylesheets V1.79.1">
<link rel="home" href="index.html" title="Programming with gtkmm 3">
<link rel="up" href="chapter-combobox.html" title="Chapter 10. Combo Boxes">
<link rel="prev" href="combobox-example-simple.html" title="Simple Text Example">
<link rel="next" href="chapter-textview.html" title="Chapter 11. TextView">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<div class="navheader">
<table width="100%" summary="Navigation header">
<tr><th colspan="3" align="center">ComboBox with an Entry</th></tr>
<tr>
<td width="20%" align="left">
<a accesskey="p" href="combobox-example-simple.html"><img src="icons/prev.png" alt="Prev"></a> </td>
<th width="60%" align="center">Chapter 10. Combo Boxes</th>
<td width="20%" align="right"> <a accesskey="n" href="chapter-textview.html"><img src="icons/next.png" alt="Next"></a>
</td>
</tr>
</table>
<hr>
</div>
<div class="sect1">
<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="sec-comboboxentry"></a>ComboBox with an Entry</h2></div></div></div>
<p>A <code class="classname">ComboBox</code> may contain an <code class="classname">Entry</code> widget for entering of arbitrary text, by specifying <code class="literal">true</code> for the constructor's <code class="literal">has_entry</code> parameter.</p>
<div class="sect2">
<div class="titlepage"><div><div><h3 class="title">
<a name="sec-comboboxentry-text-column"></a>The text column</h3></div></div></div>
<p>So that the <code class="classname">Entry</code> can interact with the drop-down list of choices, you must specify which of your model columns is the text column, with <code class="methodname">set_entry_text_column()</code>. For instance:
</p>
<pre class="programlisting">m_combo.set_entry_text_column(m_columns.m_col_name);</pre>
<p>
</p>
<p>
When you select a choice from the drop-down menu, the value from this column will be placed in the <code class="classname">Entry</code>.
</p>
</div>
<div class="sect2">
<div class="titlepage"><div><div><h3 class="title">
<a name="sec-comboboxentry-model"></a>The entry</h3></div></div></div>
<p>Because the user may enter arbitrary text, an active model row isn't enough to tell us what text the user has entered. Therefore, you should retrieve the <code class="classname">Entry</code> widget with the <code class="methodname">ComboBox::get_entry()</code> method and call <code class="methodname">get_text()</code> on that.
</p>
</div>
<div class="sect2">
<div class="titlepage"><div><div><h3 class="title">
<a name="sec-comboboxentry-changes"></a>Responding to changes</h3></div></div></div>
<p>
When the user enters arbitrary text, it may not be enough to connect to the
<code class="literal">changed</code> signal, which is emitted for every typed character.
It is not emitted when the user presses the Enter key. Pressing the Enter key or
moving the keyboard focus to another widget may signal that the user has finished
entering text. To be notified of these events, connect to the
<code class="classname">Entry</code>'s <code class="literal">activate</code> and
<code class="literal">focus_out_event</code> signals, like so
</p>
<pre class="programlisting">Gtk::Entry* entry = m_Combo.get_entry();
if (entry)
{
// The Entry shall receive focus-out events.
entry->add_events(Gdk::FOCUS_CHANGE_MASK);
// Alternatively you can connect to m_Combo.signal_changed().
entry->signal_changed().connect(sigc::mem_fun(*this,
&ExampleWindow::on_entry_changed) );
entry->signal_activate().connect(sigc::mem_fun(*this,
&ExampleWindow::on_entry_activate) );
entry->signal_focus_out_event().connect(sigc::mem_fun(*this,
&ExampleWindow::on_entry_focus_out_event) );
}</pre>
<p>
The <code class="literal">changed</code> signals of <code class="classname">ComboBox</code> and
<code class="classname">Entry</code> are both emitted for every change. It doesn't matter
which one you connect to. But only <code class="classname">Entry</code>'s
<code class="literal">focus_out_event</code> signal is useful here.
</p>
<p>
X events are described in more detail in the
<a class="link" href="sec-xeventsignals.html" title="X Event signals">X Event signals</a> section in the appendix.
</p>
</div>
<div class="sect2">
<div class="titlepage"><div><div><h3 class="title">
<a name="comboboxentry-example-full"></a>Full Example</h3></div></div></div>
<div class="figure">
<a name="figure-comboboxentry-complex"></a><p class="title"><b>Figure 10.3. ComboBox with Entry</b></p>
<div class="figure-contents"><div class="screenshot"><div><img src="figures/comboboxentry_complex.png" alt="ComboBox with Entry"></div></div></div>
</div>
<br class="figure-break"><p><a class="ulink" href="http://git.gnome.org/browse/gtkmm-documentation/tree/examples/book/combobox/entry_complex?h=gtkmm-3-24" target="_top">Source Code</a></p>
<p>File: <code class="filename">examplewindow.h</code> (For use with gtkmm 3, not gtkmm 2)
</p>
<pre class="programlisting">
#ifndef GTKMM_EXAMPLEWINDOW_H
#define GTKMM_EXAMPLEWINDOW_H
#include <gtkmm/window.h>
#include <gtkmm/combobox.h>
#include <gtkmm/liststore.h>
class ExampleWindow : public Gtk::Window
{
public:
ExampleWindow();
virtual ~ExampleWindow();
protected:
//Signal handlers:
void on_entry_changed();
void on_entry_activate();
bool on_entry_focus_out_event(GdkEventFocus* event);
//Signal connection:
sigc::connection m_ConnectionFocusOut;
//Tree model columns:
class ModelColumns : public Gtk::TreeModel::ColumnRecord
{
public:
ModelColumns()
{ add(m_col_id); add(m_col_name); }
Gtk::TreeModelColumn<Glib::ustring> m_col_id; //The data to choose - this must be text.
Gtk::TreeModelColumn<Glib::ustring> m_col_name;
};
ModelColumns m_Columns;
//Child widgets:
Gtk::ComboBox m_Combo;
Glib::RefPtr<Gtk::ListStore> m_refTreeModel;
};
#endif //GTKMM_EXAMPLEWINDOW_H
</pre>
<p>File: <code class="filename">main.cc</code> (For use with gtkmm 3, not gtkmm 2)
</p>
<pre class="programlisting">
#include "examplewindow.h"
#include <gtkmm/application.h>
int main(int argc, char *argv[])
{
auto app = Gtk::Application::create(argc, argv, "org.gtkmm.example");
ExampleWindow window;
//Shows the window and returns when it is closed.
return app->run(window);
}
</pre>
<p>File: <code class="filename">examplewindow.cc</code> (For use with gtkmm 3, not gtkmm 2)
</p>
<pre class="programlisting">
#include "examplewindow.h"
#include <iostream>
ExampleWindow::ExampleWindow()
: m_Combo(true /* has_entry */)
{
set_title("ComboBox example");
//Create the Tree model:
//m_refTreeModel = Gtk::TreeStore::create(m_Columns);
m_refTreeModel = Gtk::ListStore::create(m_Columns);
m_Combo.set_model(m_refTreeModel);
//Fill the ComboBox's Tree Model:
Gtk::TreeModel::Row row = *(m_refTreeModel->append());
row[m_Columns.m_col_id] = "1";
row[m_Columns.m_col_name] = "Billy Bob";
/*
Gtk::TreeModel::Row childrow = *(m_refTreeModel->append(row.children()));
childrow[m_Columns.m_col_id] = 11;
childrow[m_Columns.m_col_name] = "Billy Bob Junior";
childrow = *(m_refTreeModel->append(row.children()));
childrow[m_Columns.m_col_id] = 12;
childrow[m_Columns.m_col_name] = "Sue Bob";
*/
row = *(m_refTreeModel->append());
row[m_Columns.m_col_id] = "2";
row[m_Columns.m_col_name] = "Joey Jojo";
row = *(m_refTreeModel->append());
row[m_Columns.m_col_id] = "3";
row[m_Columns.m_col_name] = "Rob McRoberts";
/*
childrow = *(m_refTreeModel->append(row.children()));
childrow[m_Columns.m_col_id] = 31;
childrow[m_Columns.m_col_name] = "Xavier McRoberts";
*/
//Add the model columns to the Combo (which is a kind of view),
//rendering them in the default way:
//This is automatically rendered when we use set_entry_text_column().
//m_Combo.pack_start(m_Columns.m_col_id);
m_Combo.pack_start(m_Columns.m_col_name);
m_Combo.set_entry_text_column(m_Columns.m_col_id);
m_Combo.set_active(1);
//Add the ComboBox to the window.
add(m_Combo);
//Connect signal handlers:
auto entry = m_Combo.get_entry();
if (entry)
{
// The Entry shall receive focus-out events.
entry->add_events(Gdk::FOCUS_CHANGE_MASK);
// Alternatively you can connect to m_Combo.signal_changed().
entry->signal_changed().connect(sigc::mem_fun(*this,
&ExampleWindow::on_entry_changed) );
entry->signal_activate().connect(sigc::mem_fun(*this,
&ExampleWindow::on_entry_activate) );
m_ConnectionFocusOut = entry->signal_focus_out_event().
connect(sigc::mem_fun(*this, &ExampleWindow::on_entry_focus_out_event) );
}
else
std::cout << "No Entry ???" << std::endl;
show_all_children();
}
ExampleWindow::~ExampleWindow()
{
// The focus_out signal may be emitted while m_Combo is being destructed.
// The signal handler can generate critical messages, if it's called when
// m_Combo has been partly destructed.
m_ConnectionFocusOut.disconnect();
}
void ExampleWindow::on_entry_changed()
{
auto entry = m_Combo.get_entry();
if (entry)
{
std::cout << "on_entry_changed(): Row=" << m_Combo.get_active_row_number()
<< ", ID=" << entry->get_text() << std::endl;
}
}
void ExampleWindow::on_entry_activate()
{
auto entry = m_Combo.get_entry();
if (entry)
{
std::cout << "on_entry_activate(): Row=" << m_Combo.get_active_row_number()
<< ", ID=" << entry->get_text() << std::endl;
}
}
bool ExampleWindow::on_entry_focus_out_event(GdkEventFocus* /* event */)
{
auto entry = m_Combo.get_entry();
if (entry)
{
std::cout << "on_entry_focus_out_event(): Row=" << m_Combo.get_active_row_number()
<< ", ID=" << entry->get_text() << std::endl;
return true;
}
return false;
}
</pre>
</div>
<div class="sect2">
<div class="titlepage"><div><div><h3 class="title">
<a name="comboboxentry-example-simple"></a>Simple Text Example</h3></div></div></div>
<div class="figure">
<a name="figure-comboboxentry-text"></a><p class="title"><b>Figure 10.4. ComboBoxText with Entry</b></p>
<div class="figure-contents"><div class="screenshot"><div><img src="figures/comboboxentry_text.png" alt="ComboBoxText with Entry"></div></div></div>
</div>
<br class="figure-break"><p><a class="ulink" href="http://git.gnome.org/browse/gtkmm-documentation/tree/examples/book/combobox/entry_text?h=gtkmm-3-24" target="_top">Source Code</a></p>
<p>File: <code class="filename">examplewindow.h</code> (For use with gtkmm 3, not gtkmm 2)
</p>
<pre class="programlisting">
#ifndef GTKMM_EXAMPLEWINDOW_H
#define GTKMM_EXAMPLEWINDOW_H
#include <gtkmm/window.h>
#include <gtkmm/comboboxtext.h>
class ExampleWindow : public Gtk::Window
{
public:
ExampleWindow();
virtual ~ExampleWindow();
protected:
//Signal handlers:
void on_combo_changed();
void on_entry_activate();
bool on_entry_focus_out_event(GdkEventFocus* event);
//Signal connection:
sigc::connection m_ConnectionFocusOut;
//Child widgets:
Gtk::ComboBoxText m_Combo;
};
#endif //GTKMM_EXAMPLEWINDOW_H
</pre>
<p>File: <code class="filename">main.cc</code> (For use with gtkmm 3, not gtkmm 2)
</p>
<pre class="programlisting">
#include "examplewindow.h"
#include <gtkmm/application.h>
int main(int argc, char *argv[])
{
auto app = Gtk::Application::create(argc, argv, "org.gtkmm.example");
ExampleWindow window;
//Shows the window and returns when it is closed.
return app->run(window);
}
</pre>
<p>File: <code class="filename">examplewindow.cc</code> (For use with gtkmm 3, not gtkmm 2)
</p>
<pre class="programlisting">
#include "examplewindow.h"
#include <iostream>
ExampleWindow::ExampleWindow()
: m_Combo(true /* has_entry */)
{
set_title("ComboBoxText example");
//Fill the combo:
m_Combo.append("something");
m_Combo.append("something else");
m_Combo.append("something or other");
m_Combo.set_active(0);
add(m_Combo);
//Connect signal handlers:
auto entry = m_Combo.get_entry();
// Alternatively you can connect to entry->signal_changed().
m_Combo.signal_changed().connect(sigc::mem_fun(*this,
&ExampleWindow::on_combo_changed) );
if (entry)
{
// The Entry shall receive focus-out events.
entry->add_events(Gdk::FOCUS_CHANGE_MASK);
entry->signal_activate().connect(sigc::mem_fun(*this,
&ExampleWindow::on_entry_activate) );
m_ConnectionFocusOut = entry->signal_focus_out_event().
connect(sigc::mem_fun(*this, &ExampleWindow::on_entry_focus_out_event) );
}
else
std::cout << "No Entry ???" << std::endl;
m_Combo.property_has_frame() = false;
show_all_children();
}
ExampleWindow::~ExampleWindow()
{
// The focus_out signal may be emitted while m_Combo is being destructed.
// The signal handler can generate critical messages, if it's called when
// m_Combo has been partly destructed.
m_ConnectionFocusOut.disconnect();
}
void ExampleWindow::on_combo_changed()
{
std::cout << "on_combo_changed(): Row=" << m_Combo.get_active_row_number()
<< ", Text=" << m_Combo.get_active_text() << std::endl;
}
void ExampleWindow::on_entry_activate()
{
std::cout << "on_entry_activate(): Row=" << m_Combo.get_active_row_number()
<< ", Text=" << m_Combo.get_active_text() << std::endl;
}
bool ExampleWindow::on_entry_focus_out_event(GdkEventFocus* /* event */)
{
std::cout << "on_entry_focus_out_event(): Row=" << m_Combo.get_active_row_number()
<< ", Text=" << m_Combo.get_active_text() << std::endl;
return true;
}
</pre>
</div>
</div>
<div class="navfooter">
<hr>
<table width="100%" summary="Navigation footer">
<tr>
<td width="40%" align="left">
<a accesskey="p" href="combobox-example-simple.html"><img src="icons/prev.png" alt="Prev"></a> </td>
<td width="20%" align="center"><a accesskey="u" href="chapter-combobox.html"><img src="icons/up.png" alt="Up"></a></td>
<td width="40%" align="right"> <a accesskey="n" href="chapter-textview.html"><img src="icons/next.png" alt="Next"></a>
</td>
</tr>
<tr>
<td width="40%" align="left" valign="top">Simple Text Example </td>
<td width="20%" align="center"><a accesskey="h" href="index.html"><img src="icons/home.png" alt="Home"></a></td>
<td width="40%" align="right" valign="top"> Chapter 11. TextView</td>
</tr>
</table>
</div>
</body>
</html>
