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Toshio Sekiya
Fixed typo in sec4.src.md.
03 дек 2025, 14:25
03 дек 2025, 14:25b3d5aaf
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<h1 id="functions-in-gtknotebook">Functions in GtkNotebook</h1>
<p>GtkNotebook is a very important object in the text file editor
<code>tfe</code>. It connects the application and TfeTextView objects. A
set of public functions are declared in <code>tfenotebook.h</code>. The
word “tfenotebook” is used only in filenames. There’s no “TfeNotebook”
object.</p>
<p>The source files are in the directory <code>src/tfe5</code>. You can
get them by downloading the <a
href="https://github.com/ToshioCP/Gtk4-tutorial">repository</a>.</p>
<div class="sourceCode" id="cb1"><pre
class="sourceCode numberSource C numberLines"><code class="sourceCode c"><span id="cb1-1"><a href="#cb1-1"></a><span class="dt">void</span></span>
<span id="cb1-2"><a href="#cb1-2"></a>notebook_page_save<span class="op">(</span>GtkNotebook <span class="op">*</span>nb<span class="op">);</span></span>
<span id="cb1-3"><a href="#cb1-3"></a></span>
<span id="cb1-4"><a href="#cb1-4"></a><span class="dt">void</span></span>
<span id="cb1-5"><a href="#cb1-5"></a>notebook_page_close <span class="op">(</span>GtkNotebook <span class="op">*</span>nb<span class="op">);</span></span>
<span id="cb1-6"><a href="#cb1-6"></a></span>
<span id="cb1-7"><a href="#cb1-7"></a><span class="dt">void</span></span>
<span id="cb1-8"><a href="#cb1-8"></a>notebook_page_open <span class="op">(</span>GtkNotebook <span class="op">*</span>nb<span class="op">);</span></span>
<span id="cb1-9"><a href="#cb1-9"></a></span>
<span id="cb1-10"><a href="#cb1-10"></a><span class="dt">void</span></span>
<span id="cb1-11"><a href="#cb1-11"></a>notebook_page_new_with_file <span class="op">(</span>GtkNotebook <span class="op">*</span>nb<span class="op">,</span> GFile <span class="op">*</span>file<span class="op">);</span></span>
<span id="cb1-12"><a href="#cb1-12"></a></span>
<span id="cb1-13"><a href="#cb1-13"></a><span class="dt">void</span></span>
<span id="cb1-14"><a href="#cb1-14"></a>notebook_page_new <span class="op">(</span>GtkNotebook <span class="op">*</span>nb<span class="op">);</span></span></code></pre></div>
<p>This header file describes the public functions in
<code>tfenotebook.c</code>.</p>
<ul>
<li>1-2: <code>notebook_page_save</code> saves the current page to the
file of which the name specified in the tab. If the name is
<code>untitled</code> or <code>untitled</code> followed by digits, a
file chooser dialog appears and a user can choose or specify a
filename.</li>
<li>4-5: <code>notebook_page_close</code> closes the current page.</li>
<li>7-8: <code>notebook_page_open</code> shows a file chooser dialog and
a user can choose a file. The contents of the file is inserted to a new
page.</li>
<li>10-11: <code>notebook_page_new_with_file</code> creates a new page
and a file given as an argument is read and inserted into the page.</li>
<li>13-14: <code>notebook_page_new</code> creates a new empty page.</li>
</ul>
<p>You probably find that the functions except
<code>notebook_page_close</code> are higher level functions of</p>
<ul>
<li><code>tfe_text_view_save</code></li>
<li><code>tef_text_view_open</code></li>
<li><code>tfe_text_view_new_with_file</code></li>
<li><code>tfe_text_view_new</code></li>
</ul>
<p>respectively.</p>
<p>There are two layers. One of them is <code>tfe_text_view ...</code>,
which is the lower level layer. The other is <code>notebook ...</code>,
which is the higher level layer.</p>
<p>Now let’s look at the program of each function.</p>
<h2 id="notebook_page_new">notebook_page_new</h2>
<div class="sourceCode" id="cb2"><pre
class="sourceCode numberSource C numberLines"><code class="sourceCode c"><span id="cb2-1"><a href="#cb2-1"></a><span class="dt">static</span> <span class="dt">char</span><span class="op">*</span></span>
<span id="cb2-2"><a href="#cb2-2"></a>get_untitled <span class="op">()</span> <span class="op">{</span></span>
<span id="cb2-3"><a href="#cb2-3"></a>  <span class="dt">static</span> <span class="dt">int</span> c <span class="op">=</span> <span class="op">-</span><span class="dv">1</span><span class="op">;</span></span>
<span id="cb2-4"><a href="#cb2-4"></a>  <span class="cf">if</span> <span class="op">(++</span>c <span class="op">==</span> <span class="dv">0</span><span class="op">)</span> </span>
<span id="cb2-5"><a href="#cb2-5"></a>    <span class="cf">return</span> g_strdup_printf<span class="op">(</span><span class="st">&quot;Untitled&quot;</span><span class="op">);</span></span>
<span id="cb2-6"><a href="#cb2-6"></a>  <span class="cf">else</span></span>
<span id="cb2-7"><a href="#cb2-7"></a>    <span class="cf">return</span> g_strdup_printf <span class="op">(</span><span class="st">&quot;Untitled</span><span class="sc">%u</span><span class="st">&quot;</span><span class="op">,</span> c<span class="op">);</span></span>
<span id="cb2-8"><a href="#cb2-8"></a><span class="op">}</span></span>
<span id="cb2-9"><a href="#cb2-9"></a></span>
<span id="cb2-10"><a href="#cb2-10"></a><span class="dt">static</span> <span class="dt">void</span></span>
<span id="cb2-11"><a href="#cb2-11"></a>notebook_page_build <span class="op">(</span>GtkNotebook <span class="op">*</span>nb<span class="op">,</span> GtkWidget <span class="op">*</span>tv<span class="op">,</span> <span class="dt">const</span> <span class="dt">char</span> <span class="op">*</span>filename<span class="op">)</span> <span class="op">{</span></span>
<span id="cb2-12"><a href="#cb2-12"></a>  GtkWidget <span class="op">*</span>scr <span class="op">=</span> gtk_scrolled_window_new <span class="op">();</span></span>
<span id="cb2-13"><a href="#cb2-13"></a>  GtkNotebookPage <span class="op">*</span>nbp<span class="op">;</span></span>
<span id="cb2-14"><a href="#cb2-14"></a>  GtkWidget <span class="op">*</span>lab<span class="op">;</span></span>
<span id="cb2-15"><a href="#cb2-15"></a>  <span class="dt">int</span> i<span class="op">;</span></span>
<span id="cb2-16"><a href="#cb2-16"></a></span>
<span id="cb2-17"><a href="#cb2-17"></a>  gtk_scrolled_window_set_child <span class="op">(</span>GTK_SCROLLED_WINDOW <span class="op">(</span>scr<span class="op">),</span> tv<span class="op">);</span></span>
<span id="cb2-18"><a href="#cb2-18"></a>  lab <span class="op">=</span> gtk_label_new <span class="op">(</span>filename<span class="op">);</span></span>
<span id="cb2-19"><a href="#cb2-19"></a>  i <span class="op">=</span> gtk_notebook_append_page <span class="op">(</span>nb<span class="op">,</span> scr<span class="op">,</span> lab<span class="op">);</span></span>
<span id="cb2-20"><a href="#cb2-20"></a>  nbp <span class="op">=</span> gtk_notebook_get_page <span class="op">(</span>nb<span class="op">,</span> scr<span class="op">);</span></span>
<span id="cb2-21"><a href="#cb2-21"></a>  g_object_set <span class="op">(</span>nbp<span class="op">,</span> <span class="st">&quot;tab-expand&quot;</span><span class="op">,</span> TRUE<span class="op">,</span> NULL<span class="op">);</span></span>
<span id="cb2-22"><a href="#cb2-22"></a>  gtk_notebook_set_current_page <span class="op">(</span>nb<span class="op">,</span> i<span class="op">);</span></span>
<span id="cb2-23"><a href="#cb2-23"></a>  g_signal_connect <span class="op">(</span>GTK_TEXT_VIEW <span class="op">(</span>tv<span class="op">),</span> <span class="st">&quot;change-file&quot;</span><span class="op">,</span> G_CALLBACK <span class="op">(</span>file_changed_cb<span class="op">),</span> nb<span class="op">);</span></span>
<span id="cb2-24"><a href="#cb2-24"></a><span class="op">}</span></span>
<span id="cb2-25"><a href="#cb2-25"></a></span>
<span id="cb2-26"><a href="#cb2-26"></a><span class="dt">void</span></span>
<span id="cb2-27"><a href="#cb2-27"></a>notebook_page_new <span class="op">(</span>GtkNotebook <span class="op">*</span>nb<span class="op">)</span> <span class="op">{</span></span>
<span id="cb2-28"><a href="#cb2-28"></a>  g_return_if_fail<span class="op">(</span>GTK_IS_NOTEBOOK <span class="op">(</span>nb<span class="op">));</span></span>
<span id="cb2-29"><a href="#cb2-29"></a></span>
<span id="cb2-30"><a href="#cb2-30"></a>  GtkWidget <span class="op">*</span>tv<span class="op">;</span></span>
<span id="cb2-31"><a href="#cb2-31"></a>  <span class="dt">char</span> <span class="op">*</span>filename<span class="op">;</span></span>
<span id="cb2-32"><a href="#cb2-32"></a></span>
<span id="cb2-33"><a href="#cb2-33"></a>  tv <span class="op">=</span> tfe_text_view_new <span class="op">();</span></span>
<span id="cb2-34"><a href="#cb2-34"></a>  filename <span class="op">=</span> get_untitled <span class="op">();</span></span>
<span id="cb2-35"><a href="#cb2-35"></a>  notebook_page_build <span class="op">(</span>nb<span class="op">,</span> tv<span class="op">,</span> filename<span class="op">);</span></span>
<span id="cb2-36"><a href="#cb2-36"></a>  g_free <span class="op">(</span>filename<span class="op">);</span></span>
<span id="cb2-37"><a href="#cb2-37"></a><span class="op">}</span></span></code></pre></div>
<ul>
<li>26-37: The function <code>notebook_page_new</code>.</li>
<li>28: The function <code>g_return_if_fail</code> checks the argument.
It’s necessary because the function is public.</li>
<li>33: Creates TfeTextView object.</li>
<li>34: Creates filename, which is “Untitled”, “Untitled1”, … .</li>
<li>1-8: The function <code>get_untitled</code>.</li>
<li>3: Static variable <code>c</code> is initialized at the first call
of this function. After that <code>c</code> keeps its value unless it is
changed explicitly.</li>
<li>4-7: Increases <code>c</code> by one and if it is zero, it returns
“Untitled”. If it is a positive integer, it returns “Untitled&lt;the
integer&gt;”, for example, “Untitled1”, “Untitled2”, and so on. The
function <code>g_strdup_printf</code> creates a string and it should be
freed by <code>g_free</code> when it becomes useless. The caller of
<code>get_untitled</code> is in charge of freeing the string.</li>
<li>36: Calls <code>notebook_page_build</code> to build a new page.</li>
<li>37: Frees <code>filename</code>.</li>
<li>10- 24: The function <code>notebook_page_build</code>. A parameter
with <code>const</code> qualifier doesn’t change in the function. It
means that the argument <code>filename</code> is owned by the caller.
The caller needs to free it when it becomes useless.</li>
<li>12: Creates GtkScrolledWindow.</li>
<li>17: Inserts <code>tv</code> to GtkScrolledWindow as a child.</li>
<li>18-19: Creates GtkLabel, then appends <code>scr</code> and
<code>lab</code> to the GtkNotebook instance <code>nb</code>.</li>
<li>20-21: Sets “tab-expand” property to TRUE. The function
<code>g_object_set</code> sets properties on an object. The object can
be any object derived from GObject. In many cases, an object has its own
function to set its properties, but sometimes doesn’t. In that case, use
<code>g_object_set</code> to set the property.</li>
<li>22: Sets the current page to the newly created page.</li>
<li>23: Connects “change-file” signal and the handler
<code>file_changed_cb</code>.</li>
</ul>
<h2 id="notebook_page_new_with_file">notebook_page_new_with_file</h2>
<div class="sourceCode" id="cb3"><pre
class="sourceCode numberSource C numberLines"><code class="sourceCode c"><span id="cb3-1"><a href="#cb3-1"></a><span class="dt">void</span></span>
<span id="cb3-2"><a href="#cb3-2"></a>notebook_page_new_with_file <span class="op">(</span>GtkNotebook <span class="op">*</span>nb<span class="op">,</span> GFile <span class="op">*</span>file<span class="op">)</span> <span class="op">{</span></span>
<span id="cb3-3"><a href="#cb3-3"></a>  g_return_if_fail<span class="op">(</span>GTK_IS_NOTEBOOK <span class="op">(</span>nb<span class="op">));</span></span>
<span id="cb3-4"><a href="#cb3-4"></a>  g_return_if_fail<span class="op">(</span>G_IS_FILE <span class="op">(</span>file<span class="op">));</span></span>
<span id="cb3-5"><a href="#cb3-5"></a></span>
<span id="cb3-6"><a href="#cb3-6"></a>  GtkWidget <span class="op">*</span>tv<span class="op">;</span></span>
<span id="cb3-7"><a href="#cb3-7"></a>  <span class="dt">char</span> <span class="op">*</span>filename<span class="op">;</span></span>
<span id="cb3-8"><a href="#cb3-8"></a></span>
<span id="cb3-9"><a href="#cb3-9"></a>  <span class="cf">if</span> <span class="op">((</span>tv <span class="op">=</span> tfe_text_view_new_with_file <span class="op">(</span>file<span class="op">))</span> <span class="op">==</span> NULL<span class="op">)</span></span>
<span id="cb3-10"><a href="#cb3-10"></a>    <span class="cf">return</span><span class="op">;</span> <span class="co">/* read error */</span></span>
<span id="cb3-11"><a href="#cb3-11"></a>  filename <span class="op">=</span> g_file_get_basename <span class="op">(</span>file<span class="op">);</span></span>
<span id="cb3-12"><a href="#cb3-12"></a>  notebook_page_build <span class="op">(</span>nb<span class="op">,</span> tv<span class="op">,</span> filename<span class="op">);</span></span>
<span id="cb3-13"><a href="#cb3-13"></a>  g_free <span class="op">(</span>filename<span class="op">);</span></span>
<span id="cb3-14"><a href="#cb3-14"></a><span class="op">}</span></span></code></pre></div>
<ul>
<li>9-10: Calls <code>tfe_text_view_new_with_file</code>. If the
function returns NULL, an error has happened. Then, it does nothing and
returns.</li>
<li>11-13: Gets the filename, builds a new page and frees
<code>filename</code>.</li>
</ul>
<h2 id="notebook_page_open">notebook_page_open</h2>
<div class="sourceCode" id="cb4"><pre
class="sourceCode numberSource C numberLines"><code class="sourceCode c"><span id="cb4-1"><a href="#cb4-1"></a><span class="dt">static</span> <span class="dt">void</span></span>
<span id="cb4-2"><a href="#cb4-2"></a>open_response_cb <span class="op">(</span>TfeTextView <span class="op">*</span>tv<span class="op">,</span> <span class="dt">int</span> response<span class="op">,</span> GtkNotebook <span class="op">*</span>nb<span class="op">)</span> <span class="op">{</span></span>
<span id="cb4-3"><a href="#cb4-3"></a>  GFile <span class="op">*</span>file<span class="op">;</span></span>
<span id="cb4-4"><a href="#cb4-4"></a>  <span class="dt">char</span> <span class="op">*</span>filename<span class="op">;</span></span>
<span id="cb4-5"><a href="#cb4-5"></a></span>
<span id="cb4-6"><a href="#cb4-6"></a>  <span class="cf">if</span> <span class="op">(</span>response <span class="op">!=</span> TFE_OPEN_RESPONSE_SUCCESS<span class="op">)</span> <span class="op">{</span></span>
<span id="cb4-7"><a href="#cb4-7"></a>    g_object_ref_sink <span class="op">(</span>tv<span class="op">);</span></span>
<span id="cb4-8"><a href="#cb4-8"></a>    g_object_unref <span class="op">(</span>tv<span class="op">);</span></span>
<span id="cb4-9"><a href="#cb4-9"></a>  <span class="op">}</span><span class="cf">else</span> <span class="op">{</span></span>
<span id="cb4-10"><a href="#cb4-10"></a>    file <span class="op">=</span> tfe_text_view_get_file <span class="op">(</span>tv<span class="op">);</span></span>
<span id="cb4-11"><a href="#cb4-11"></a>    filename <span class="op">=</span> g_file_get_basename <span class="op">(</span>file<span class="op">);</span></span>
<span id="cb4-12"><a href="#cb4-12"></a>    g_object_unref <span class="op">(</span>file<span class="op">);</span></span>
<span id="cb4-13"><a href="#cb4-13"></a>    notebook_page_build <span class="op">(</span>nb<span class="op">,</span> GTK_WIDGET <span class="op">(</span>tv<span class="op">),</span> filename<span class="op">);</span></span>
<span id="cb4-14"><a href="#cb4-14"></a>    g_free <span class="op">(</span>filename<span class="op">);</span></span>
<span id="cb4-15"><a href="#cb4-15"></a>  <span class="op">}</span></span>
<span id="cb4-16"><a href="#cb4-16"></a><span class="op">}</span></span>
<span id="cb4-17"><a href="#cb4-17"></a></span>
<span id="cb4-18"><a href="#cb4-18"></a><span class="dt">void</span></span>
<span id="cb4-19"><a href="#cb4-19"></a>notebook_page_open <span class="op">(</span>GtkNotebook <span class="op">*</span>nb<span class="op">)</span> <span class="op">{</span></span>
<span id="cb4-20"><a href="#cb4-20"></a>  g_return_if_fail<span class="op">(</span>GTK_IS_NOTEBOOK <span class="op">(</span>nb<span class="op">));</span></span>
<span id="cb4-21"><a href="#cb4-21"></a></span>
<span id="cb4-22"><a href="#cb4-22"></a>  GtkWidget <span class="op">*</span>tv<span class="op">;</span></span>
<span id="cb4-23"><a href="#cb4-23"></a></span>
<span id="cb4-24"><a href="#cb4-24"></a>  tv <span class="op">=</span> tfe_text_view_new <span class="op">();</span></span>
<span id="cb4-25"><a href="#cb4-25"></a>  g_signal_connect <span class="op">(</span>TFE_TEXT_VIEW <span class="op">(</span>tv<span class="op">),</span> <span class="st">&quot;open-response&quot;</span><span class="op">,</span> G_CALLBACK <span class="op">(</span>open_response_cb<span class="op">),</span> nb<span class="op">);</span></span>
<span id="cb4-26"><a href="#cb4-26"></a>  tfe_text_view_open <span class="op">(</span>TFE_TEXT_VIEW <span class="op">(</span>tv<span class="op">),</span> GTK_WINDOW <span class="op">(</span>gtk_widget_get_ancestor <span class="op">(</span>GTK_WIDGET <span class="op">(</span>nb<span class="op">),</span> GTK_TYPE_WINDOW<span class="op">)));</span></span>
<span id="cb4-27"><a href="#cb4-27"></a><span class="op">}</span></span></code></pre></div>
<ul>
<li>18-27: The function <code>notebook_page_open</code>.</li>
<li>24: Creates TfeTextView object.</li>
<li>25: Connects the signal “open-response” and the handler
<code>open_response_cb</code>.</li>
<li>26: Calls <code>tfe_text_view_open</code>. The “open-response”
signal will be emitted later in this function to inform the result.</li>
<li>1-16: The handler <code>open_response_cb</code>.</li>
<li>6-8: If the response code is not
<code>TFE_OPEN_RESPONSE_SUCCESS</code>, the instance <code>tv</code>
will be destroyed. It has floating reference, which will be explained
later. A floating reference needs to be converted into an ordinary
reference before releasing it. The function
<code>g_object_ref_sink</code> does that. After that, the function
<code>g_object_unref</code> releases <code>tv</code> and decreases the
reference count by one. Finally the reference count becomes zero and
<code>tv</code> is destroyed.</li>
<li>9-15: Otherwise, it builds a new page with <code>tv</code>.</li>
</ul>
<h2 id="floating-reference">Floating reference</h2>
<p>All the widgets are derived from GInitiallyUnowned. GObject and
GInitiallyUnowned are almost the same. The difference is like this. When
an instance of GInitiallyUnowned is created, the instance has a
“floating reference”. On the other hand, when an instance of GObject
(not GInitiallyUnowned) is created, it has “normal reference”. Their
descendants inherits them, so every widget has a floating reference just
after the creation. Non-widget class, for example, GtkTextBuffer is a
direct sub class of GObject and it has normal reference.</p>
<p>The function <code>g_object_ref_sink</code> converts the floating
reference into a normal reference. If the instance doesn’t have a
floating reference, <code>g_object_ref_sink</code> simply increases the
reference count by one. It is used when an widget is added to another
widget as a child.</p>
<pre><code>GtkTextView *tv = gtk_text_view_new (); // Floating reference
GtkScrolledWindow *scr = gtk_scrolled_window_new ();
gtk_scrolled_window_set_child (scr, tv); // Scrolled window sink the tv&#39;s floating reference and tv&#39;s reference count becomes one.</code></pre>
<p>When <code>tv</code> is added to <code>scr</code> as a child,
<code>g_object_ref_sink</code> is used.</p>
<pre><code>g_object_ref_sink (tv);</code></pre>
<p>So, the floating reference is converted into an ordinary reference.
That is to say, floating reference is removed, and the normal reference
count is one. Thanks to this, the caller doesn’t need to decrease tv’s
reference count. If an Object_A is not a descendant of
GInitiallyUnowned, the program is like this:</p>
<pre><code>Object_A *obj_a = object_a_new (); // reference count is one
GtkScrolledWindow *scr = gtk_scrolled_window_new ();
gtk_scrolled_window_set_child (scr, obj_a); // obj_a&#39;s reference count is two
// obj_a is referred by the caller (this program) and scrolled window
g_object_unref (obj_a); // obj_a&#39;s reference count is one because the caller no longer refers obj_a.</code></pre>
<p>This example tells us that the caller needs to unref
<code>obj_a</code>.</p>
<p>If you use <code>g_object_unref</code> to an instance that has a
floating reference, you need to convert the floating reference to a
normal reference in advance. See <a
href="https://docs.gtk.org/gobject/floating-refs.html">GObject API
reference</a> for further information.</p>
<h2 id="notebook_page_close">notebook_page_close</h2>
<div class="sourceCode" id="cb8"><pre
class="sourceCode numberSource C numberLines"><code class="sourceCode c"><span id="cb8-1"><a href="#cb8-1"></a><span class="dt">void</span></span>
<span id="cb8-2"><a href="#cb8-2"></a>notebook_page_close <span class="op">(</span>GtkNotebook <span class="op">*</span>nb<span class="op">)</span> <span class="op">{</span></span>
<span id="cb8-3"><a href="#cb8-3"></a>  g_return_if_fail<span class="op">(</span>GTK_IS_NOTEBOOK <span class="op">(</span>nb<span class="op">));</span></span>
<span id="cb8-4"><a href="#cb8-4"></a></span>
<span id="cb8-5"><a href="#cb8-5"></a>  GtkWidget <span class="op">*</span>win<span class="op">;</span></span>
<span id="cb8-6"><a href="#cb8-6"></a>  <span class="dt">int</span> i<span class="op">;</span></span>
<span id="cb8-7"><a href="#cb8-7"></a></span>
<span id="cb8-8"><a href="#cb8-8"></a>  <span class="cf">if</span> <span class="op">(</span>gtk_notebook_get_n_pages <span class="op">(</span>nb<span class="op">)</span> <span class="op">==</span> <span class="dv">1</span><span class="op">)</span> <span class="op">{</span></span>
<span id="cb8-9"><a href="#cb8-9"></a>    win <span class="op">=</span> gtk_widget_get_ancestor <span class="op">(</span>GTK_WIDGET <span class="op">(</span>nb<span class="op">),</span> GTK_TYPE_WINDOW<span class="op">);</span></span>
<span id="cb8-10"><a href="#cb8-10"></a>    gtk_window_destroy<span class="op">(</span>GTK_WINDOW <span class="op">(</span>win<span class="op">));</span></span>
<span id="cb8-11"><a href="#cb8-11"></a>  <span class="op">}</span> <span class="cf">else</span> <span class="op">{</span></span>
<span id="cb8-12"><a href="#cb8-12"></a>    i <span class="op">=</span> gtk_notebook_get_current_page <span class="op">(</span>nb<span class="op">);</span></span>
<span id="cb8-13"><a href="#cb8-13"></a>    gtk_notebook_remove_page <span class="op">(</span>GTK_NOTEBOOK <span class="op">(</span>nb<span class="op">),</span> i<span class="op">);</span></span>
<span id="cb8-14"><a href="#cb8-14"></a>  <span class="op">}</span></span>
<span id="cb8-15"><a href="#cb8-15"></a><span class="op">}</span></span></code></pre></div>
<p>This function closes the current page. If the page is the only page
the notebook has, then the function destroys the top-level window and
quits the application.</p>
<ul>
<li>8-10: If the page is the only page the notebook has, it calls
<code>gtk_window_destroy</code> to destroy the top-level window.</li>
<li>11-13: Otherwise, removes the current page. The child widget
(TfeTextView) is also destroyed.</li>
</ul>
<h2 id="notebook_page_save">notebook_page_save</h2>
<div class="sourceCode" id="cb9"><pre
class="sourceCode numberSource C numberLines"><code class="sourceCode c"><span id="cb9-1"><a href="#cb9-1"></a><span class="dt">static</span> TfeTextView <span class="op">*</span></span>
<span id="cb9-2"><a href="#cb9-2"></a>get_current_textview <span class="op">(</span>GtkNotebook <span class="op">*</span>nb<span class="op">)</span> <span class="op">{</span></span>
<span id="cb9-3"><a href="#cb9-3"></a>  <span class="dt">int</span> i<span class="op">;</span></span>
<span id="cb9-4"><a href="#cb9-4"></a>  GtkWidget <span class="op">*</span>scr<span class="op">;</span></span>
<span id="cb9-5"><a href="#cb9-5"></a>  GtkWidget <span class="op">*</span>tv<span class="op">;</span></span>
<span id="cb9-6"><a href="#cb9-6"></a></span>
<span id="cb9-7"><a href="#cb9-7"></a>  i <span class="op">=</span> gtk_notebook_get_current_page <span class="op">(</span>nb<span class="op">);</span></span>
<span id="cb9-8"><a href="#cb9-8"></a>  scr <span class="op">=</span> gtk_notebook_get_nth_page <span class="op">(</span>nb<span class="op">,</span> i<span class="op">);</span></span>
<span id="cb9-9"><a href="#cb9-9"></a>  tv <span class="op">=</span> gtk_scrolled_window_get_child <span class="op">(</span>GTK_SCROLLED_WINDOW <span class="op">(</span>scr<span class="op">));</span></span>
<span id="cb9-10"><a href="#cb9-10"></a>  <span class="cf">return</span> TFE_TEXT_VIEW <span class="op">(</span>tv<span class="op">);</span></span>
<span id="cb9-11"><a href="#cb9-11"></a><span class="op">}</span></span>
<span id="cb9-12"><a href="#cb9-12"></a></span>
<span id="cb9-13"><a href="#cb9-13"></a><span class="dt">void</span></span>
<span id="cb9-14"><a href="#cb9-14"></a>notebook_page_save <span class="op">(</span>GtkNotebook <span class="op">*</span>nb<span class="op">)</span> <span class="op">{</span></span>
<span id="cb9-15"><a href="#cb9-15"></a>  g_return_if_fail<span class="op">(</span>GTK_IS_NOTEBOOK <span class="op">(</span>nb<span class="op">));</span></span>
<span id="cb9-16"><a href="#cb9-16"></a></span>
<span id="cb9-17"><a href="#cb9-17"></a>  TfeTextView <span class="op">*</span>tv<span class="op">;</span></span>
<span id="cb9-18"><a href="#cb9-18"></a></span>
<span id="cb9-19"><a href="#cb9-19"></a>  tv <span class="op">=</span> get_current_textview <span class="op">(</span>nb<span class="op">);</span></span>
<span id="cb9-20"><a href="#cb9-20"></a>  tfe_text_view_save <span class="op">(</span>tv<span class="op">);</span></span>
<span id="cb9-21"><a href="#cb9-21"></a><span class="op">}</span></span></code></pre></div>
<ul>
<li>13-21: <code>notebook_page_save</code>.</li>
<li>19: Gets the TfeTextView instance belongs to the current page. The
caller doesn’t have the ownership of <code>tv</code> so you don’t need
to care about freeing it.</li>
<li>20: Calls <code>tfe_text_view_save</code>.</li>
<li>1-11: <code>get_current_textview</code>. This function gets the
TfeTextView object belongs to the current page.</li>
<li>7: Gets the page number of the current page.</li>
<li>8: Gets the child widget <code>scr</code>, which is a
GtkScrolledWindow instance, of the current page. The object
<code>scr</code> is owned by the notebook <code>nb</code>. So, the
caller doesn’t need to free it.</li>
<li>9-10: Gets the child widget of <code>scr</code>, which is a
TfeTextView instance, and returns it. The returned instance is owned by
<code>scr</code> and the caller of <code>get_cuurent_textview</code>
doesn’t need to care about freeing it.</li>
</ul>
<h2 id="file_changed_cb-handler">file_changed_cb handler</h2>
<p>The function <code>file_changed_cb</code> is a handler connected to
“change-file” signal. If a file in a TfeTextView instance is changed,
the instance emits this signal. This handler changes the label of the
GtkNotebookPage.</p>
<div class="sourceCode" id="cb10"><pre
class="sourceCode numberSource C numberLines"><code class="sourceCode c"><span id="cb10-1"><a href="#cb10-1"></a><span class="dt">static</span> <span class="dt">void</span></span>
<span id="cb10-2"><a href="#cb10-2"></a>file_changed_cb <span class="op">(</span>TfeTextView <span class="op">*</span>tv<span class="op">,</span> GtkNotebook <span class="op">*</span>nb<span class="op">)</span> <span class="op">{</span></span>
<span id="cb10-3"><a href="#cb10-3"></a>  GtkWidget <span class="op">*</span>scr<span class="op">;</span></span>
<span id="cb10-4"><a href="#cb10-4"></a>  GtkWidget <span class="op">*</span>label<span class="op">;</span></span>
<span id="cb10-5"><a href="#cb10-5"></a>  GFile <span class="op">*</span>file<span class="op">;</span></span>
<span id="cb10-6"><a href="#cb10-6"></a>  <span class="dt">char</span> <span class="op">*</span>filename<span class="op">;</span></span>
<span id="cb10-7"><a href="#cb10-7"></a></span>
<span id="cb10-8"><a href="#cb10-8"></a>  file <span class="op">=</span> tfe_text_view_get_file <span class="op">(</span>tv<span class="op">);</span></span>
<span id="cb10-9"><a href="#cb10-9"></a>  scr <span class="op">=</span> gtk_widget_get_parent <span class="op">(</span>GTK_WIDGET <span class="op">(</span>tv<span class="op">));</span></span>
<span id="cb10-10"><a href="#cb10-10"></a>  <span class="cf">if</span> <span class="op">(</span>G_IS_FILE <span class="op">(</span>file<span class="op">))</span> <span class="op">{</span></span>
<span id="cb10-11"><a href="#cb10-11"></a>    filename <span class="op">=</span> g_file_get_basename <span class="op">(</span>file<span class="op">);</span></span>
<span id="cb10-12"><a href="#cb10-12"></a>    g_object_unref <span class="op">(</span>file<span class="op">);</span></span>
<span id="cb10-13"><a href="#cb10-13"></a>  <span class="op">}</span> <span class="cf">else</span></span>
<span id="cb10-14"><a href="#cb10-14"></a>    filename <span class="op">=</span> get_untitled <span class="op">();</span></span>
<span id="cb10-15"><a href="#cb10-15"></a>  label <span class="op">=</span> gtk_label_new <span class="op">(</span>filename<span class="op">);</span></span>
<span id="cb10-16"><a href="#cb10-16"></a>  g_free <span class="op">(</span>filename<span class="op">);</span></span>
<span id="cb10-17"><a href="#cb10-17"></a>  gtk_notebook_set_tab_label <span class="op">(</span>nb<span class="op">,</span> scr<span class="op">,</span> label<span class="op">);</span></span>
<span id="cb10-18"><a href="#cb10-18"></a><span class="op">}</span></span></code></pre></div>
<ul>
<li>8: Gets the GFile instance from <code>tv</code>.</li>
<li>9: Gets the GkScrolledWindow instance which is the parent widget of
<code>tv</code>.</li>
<li>10-12: If <code>file</code> points a GFile instance, the filename of
the GFile is assigned to <code>filename</code>. Then, unref the GFile
object <code>file</code>.</li>
<li>13-14: Otherwise (file is NULL), a string
<code>Untitled(number)</code> is assigned to <code>filename</code>.</li>
<li>15-17: Creates a GtkLabel instance <code>label</code> with the
filename and set the label of the GtkNotebookPage with
<code>label</code>.</li>
</ul>
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