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<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="sec-buildapp-opening-files"></a>Opening files</h2></div></div></div>
<p>
In this step, we make our application show the contents of all the files that it is
given on the commandline.
</p>
<p>
To this end, we add a data member to our application window and keep a pointer to the
<code class="classname">Gtk::Stack</code> there. We get the pointer with a call to
<code class="methodname">Gtk::Builder::get_widget()</code> in the application window's constructor.
</p>
<p>
Now we revisit the <code class="methodname">ExampleAppWindow::open_file_view()</code> method
that is called for each commandline argument, and construct a <code class="classname">Gtk::TextView</code>
that we then add as a page to the stack.
</p>
<p>
Note that we do not have to touch the stack switcher at all. It gets all its information
from the stack that it belongs to. Here, we are passing the label to show for each file
as the last argument to the <code class="methodname">Gtk::Stack::add()</code> method.
</p>
<p>
Our application is beginning to take shape:
</p>
<div class="figure">
<a name="figure-buildapp-opening-files"></a><p class="title"><b>Figure 31.3. Opening files</b></p>
<div class="figure-contents"><div class="screenshot"><div><img src="figures/buildapp_opening_files.png" alt="Opening files"></div></div></div>
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<br class="figure-break"><p><a class="ulink" href="http://git.gnome.org/browse/gtkmm-documentation/tree/examples/book/buildapp/step3?h=gtkmm-3-24" target="_top">Source Code</a></p>
<p>File: <code class="filename">exampleappwindow.h</code> (For use with gtkmm 3, not gtkmm 2)
</p>
<pre class="programlisting">
#ifndef GTKMM_EXAMPLEAPPWINDOW_H_
#define GTKMM_EXAMPLEAPPWINDOW_H_
#include <gtkmm.h>
class ExampleAppWindow : public Gtk::ApplicationWindow
{
public:
ExampleAppWindow(BaseObjectType* cobject,
const Glib::RefPtr<Gtk::Builder>& refBuilder);
static ExampleAppWindow* create();
void open_file_view(const Glib::RefPtr<Gio::File>& file);
protected:
Glib::RefPtr<Gtk::Builder> m_refBuilder;
Gtk::Stack* m_stack;
};
#endif /* GTKMM_EXAMPLEAPPWINDOW_H */
</pre>
<p>File: <code class="filename">exampleapplication.h</code> (For use with gtkmm 3, not gtkmm 2)
</p>
<pre class="programlisting">
#include "../step1/exampleapplication.h"
// Equal to the corresponding file in step1
</pre>
<p>File: <code class="filename">exampleapplication.cc</code> (For use with gtkmm 3, not gtkmm 2)
</p>
<pre class="programlisting">
#include "../step2/exampleapplication.cc"
// Equal to the corresponding file in step2
</pre>
<p>File: <code class="filename">main.cc</code> (For use with gtkmm 3, not gtkmm 2)
</p>
<pre class="programlisting">
#include "../step1/main.cc"
// Equal to the corresponding file in step1
</pre>
<p>File: <code class="filename">exampleappwindow.cc</code> (For use with gtkmm 3, not gtkmm 2)
</p>
<pre class="programlisting">
#include "exampleappwindow.h"
#include <iostream>
#include <stdexcept>
ExampleAppWindow::ExampleAppWindow(BaseObjectType* cobject,
const Glib::RefPtr<Gtk::Builder>& refBuilder)
: Gtk::ApplicationWindow(cobject),
m_refBuilder(refBuilder),
m_stack(nullptr)
{
m_refBuilder->get_widget("stack", m_stack);
if (!m_stack)
throw std::runtime_error("No \"stack\" object in window.ui");
}
//static
ExampleAppWindow* ExampleAppWindow::create()
{
// Load the Builder file and instantiate its widgets.
auto refBuilder = Gtk::Builder::create_from_resource("/org/gtkmm/exampleapp/window.ui");
ExampleAppWindow* window = nullptr;
refBuilder->get_widget_derived("app_window", window);
if (!window)
throw std::runtime_error("No \"app_window\" object in window.ui");
return window;
}
void ExampleAppWindow::open_file_view(const Glib::RefPtr<Gio::File>& file)
{
const auto basename = file->get_basename();
auto scrolled = Gtk::make_managed<Gtk::ScrolledWindow>();
scrolled->set_hexpand(true);
scrolled->set_vexpand(true);
scrolled->show();
auto view = Gtk::make_managed<Gtk::TextView>();
view->set_editable(false);
view->set_cursor_visible(false);
view->show();
scrolled->add(*view);
m_stack->add(*scrolled, basename, basename);
try
{
char* contents = nullptr;
gsize length = 0;
file->load_contents(contents, length);
view->get_buffer()->set_text(contents, contents+length);
g_free(contents);
}
catch (const Glib::Error& ex)
{
std::cout << "ExampleAppWindow::open_file_view(\"" << file->get_parse_name()
<< "\"):\n " << ex.what() << std::endl;
}
}
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