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Toshio Sekiya
Fixed typo in sec4.src.md.
03 дек 2025, 14:25
03 дек 2025, 14:25
b3d5aaf
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border: 1px solid;} img {display: block; margin-left: auto; margin-right: auto;} figcaption {text-align: center;} </style> </head> <body style="padding-top: 70px;"> <div class="container"> <nav class="navbar fixed-top navbar-expand-lg navbar-dark bg-primary"> <div class="container-fluid"> <span class="navbar-brand">Gtk4 tutorial</span> <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation"> <span class="navbar-toggler-icon"></span> </button> <div class="collapse navbar-collapse" id="navbarSupportedContent"> <ul class="navbar-nav me-auto mb-2 mb-lg-0"> <li class="nav-item"> <a class="nav-link" href="index.html">Home</a> </li> <li class="nav-item"> <a class="nav-link" href="sec19.html">Prev: section19</a> </li> <li class="nav-item"> <a class="nav-link" href="sec21.html">Next: section21</a> </li> </ul> </div> </div> </nav> <div class="row justify-content-center"> <div class="col-xl-10 col-xxl-9"> <h1 id="composite-widgets-and-alert-dialog">Composite widgets and alert dialog</h1> <p>The source files are in the <a href="https://github.com/ToshioCP/Gtk4-tutorial">Gtk4 tutorial GitHub repository</a>. Download it and see <code>src/tfe6</code> directory.</p> <h2 id="an-outline-of-new-tfe-text-editor">An outline of new Tfe text editor</h2> <p>Tfe text editor will be restructured. The program is divided into six parts.</p> <ul> <li>Main program: the C main function.</li> <li>TfeApplication object: It is like GtkApplication but keeps GSettings and CSS Provider.</li> <li>TfeWindow object: It is a window with buttons and a notebook.</li> <li>TfePref object: A preference dialog.</li> <li>TfeAlert object: An alert dialog.</li> <li>pdf2css.h and pdf2css.c: Font and CSS utility functions.</li> </ul> <p>This section describes TfeAlert. Others will be explained in the following sections.</p> <h2 id="composite-widgets">Composite widgets</h2> <p>The alert dialog is like this:</p> <figure> <img src="image/alert.png" alt="Alert dialog" /> <figcaption aria-hidden="true">Alert dialog</figcaption> </figure> <p>Tfe uses it when a user quits the application or closes a notebook without saving data to files.</p> <p>The dialog has a title, buttons, an icon and a message. Therefore, it consists of several widgets. Such dialog is called a composite widget.</p> <p>Composite widgets are defined with template XMLs. The class is built in the class initialization function and the instances are built and desposed by the following functions.</p> <ul> <li>gtk_widget_init_template</li> <li>gtk_widget_dispose_template</li> </ul> <p>TfeAlert is a good example to know composite widgets. It is defined with the three files.</p> <ul> <li>tfealert.ui: XML file</li> <li>tfealert.h: Header file</li> <li>tfealert.c: C program file</li> </ul> <h2 id="the-xml-file">The XML file</h2> <p>A template tag is used in a composite widget XML.</p> <div class="sourceCode" id="cb1"><pre class="sourceCode numberSource xml numberLines"><code class="sourceCode xml"><span id="cb1-1"><a href="#cb1-1"></a><span class="fu"><?xml</span><span class="ot"> version=</span><span class="st">"1.0"</span><span class="ot"> encoding=</span><span class="st">"UTF-8"</span><span class="fu">?></span></span> <span id="cb1-2"><a href="#cb1-2"></a><<span class="kw">interface</span>></span> <span id="cb1-3"><a href="#cb1-3"></a> <<span class="kw">template</span><span class="ot"> class=</span><span class="st">"TfeAlert"</span><span class="ot"> parent=</span><span class="st">"GtkWindow"</span>></span> <span id="cb1-4"><a href="#cb1-4"></a> <<span class="kw">property</span><span class="ot"> name=</span><span class="st">"resizable"</span>>FALSE</<span class="kw">property</span>></span> <span id="cb1-5"><a href="#cb1-5"></a> <<span class="kw">property</span><span class="ot"> name=</span><span class="st">"modal"</span>>TRUE</<span class="kw">property</span>></span> <span id="cb1-6"><a href="#cb1-6"></a> <<span class="kw">property</span><span class="ot"> name=</span><span class="st">"titlebar"</span>></span> <span id="cb1-7"><a href="#cb1-7"></a> <<span class="kw">object</span><span class="ot"> class=</span><span class="st">"GtkHeaderBar"</span>></span> <span id="cb1-8"><a href="#cb1-8"></a> <<span class="kw">property</span><span class="ot"> name=</span><span class="st">"show-title-buttons"</span>>FALSE</<span class="kw">property</span>></span> <span id="cb1-9"><a href="#cb1-9"></a> <<span class="kw">property</span><span class="ot"> name=</span><span class="st">"title-widget"</span>></span> <span id="cb1-10"><a href="#cb1-10"></a> <<span class="kw">object</span><span class="ot"> class=</span><span class="st">"GtkLabel"</span><span class="ot"> id=</span><span class="st">"lb_title"</span>></span> <span id="cb1-11"><a href="#cb1-11"></a> <<span class="kw">property</span><span class="ot"> name=</span><span class="st">"label"</span>>Are you sure?</<span class="kw">property</span>></span> <span id="cb1-12"><a href="#cb1-12"></a> <<span class="kw">property</span><span class="ot"> name=</span><span class="st">"single-line-mode"</span>>True</<span class="kw">property</span>></span> <span id="cb1-13"><a href="#cb1-13"></a> </<span class="kw">object</span>></span> <span id="cb1-14"><a href="#cb1-14"></a> </<span class="kw">property</span>></span> <span id="cb1-15"><a href="#cb1-15"></a> <<span class="kw">child</span><span class="ot"> type=</span><span class="st">"start"</span>></span> <span id="cb1-16"><a href="#cb1-16"></a> <<span class="kw">object</span><span class="ot"> class=</span><span class="st">"GtkButton"</span><span class="ot"> id=</span><span class="st">"btn_cancel"</span>></span> <span id="cb1-17"><a href="#cb1-17"></a> <<span class="kw">property</span><span class="ot"> name=</span><span class="st">"label"</span>>Cancel</<span class="kw">property</span>></span> <span id="cb1-18"><a href="#cb1-18"></a> <<span class="kw">style</span>></span> <span id="cb1-19"><a href="#cb1-19"></a> <<span class="kw">class</span><span class="ot"> name=</span><span class="st">"suggested-action"</span>/></span> <span id="cb1-20"><a href="#cb1-20"></a> </<span class="kw">style</span>></span> <span id="cb1-21"><a href="#cb1-21"></a> <<span class="kw">signal</span><span class="ot"> name=</span><span class="st">"clicked"</span><span class="ot"> handler=</span><span class="st">"cancel_cb"</span><span class="ot"> swapped=</span><span class="st">"TRUE"</span><span class="ot"> object=</span><span class="st">"TfeAlert"</span>></<span class="kw">signal</span>></span> <span id="cb1-22"><a href="#cb1-22"></a> </<span class="kw">object</span>></span> <span id="cb1-23"><a href="#cb1-23"></a> </<span class="kw">child</span>></span> <span id="cb1-24"><a href="#cb1-24"></a> <<span class="kw">child</span><span class="ot"> type=</span><span class="st">"end"</span>></span> <span id="cb1-25"><a href="#cb1-25"></a> <<span class="kw">object</span><span class="ot"> class=</span><span class="st">"GtkButton"</span><span class="ot"> id=</span><span class="st">"btn_accept"</span>></span> <span id="cb1-26"><a href="#cb1-26"></a> <<span class="kw">property</span><span class="ot"> name=</span><span class="st">"label"</span>>Close</<span class="kw">property</span>></span> <span id="cb1-27"><a href="#cb1-27"></a> <<span class="kw">style</span>></span> <span id="cb1-28"><a href="#cb1-28"></a> <<span class="kw">class</span><span class="ot"> name=</span><span class="st">"destructive-action"</span>/></span> <span id="cb1-29"><a href="#cb1-29"></a> </<span class="kw">style</span>></span> <span id="cb1-30"><a href="#cb1-30"></a> <<span class="kw">signal</span><span class="ot"> name=</span><span class="st">"clicked"</span><span class="ot"> handler=</span><span class="st">"accept_cb"</span><span class="ot"> swapped=</span><span class="st">"TRUE"</span><span class="ot"> object=</span><span class="st">"TfeAlert"</span>></<span class="kw">signal</span>></span> <span id="cb1-31"><a href="#cb1-31"></a> </<span class="kw">object</span>></span> <span id="cb1-32"><a href="#cb1-32"></a> </<span class="kw">child</span>></span> <span id="cb1-33"><a href="#cb1-33"></a> </<span class="kw">object</span>></span> <span id="cb1-34"><a href="#cb1-34"></a> </<span class="kw">property</span>></span> <span id="cb1-35"><a href="#cb1-35"></a> <<span class="kw">child</span>></span> <span id="cb1-36"><a href="#cb1-36"></a> <<span class="kw">object</span><span class="ot"> class=</span><span class="st">"GtkBox"</span>></span> <span id="cb1-37"><a href="#cb1-37"></a> <<span class="kw">property</span><span class="ot"> name=</span><span class="st">"orientation"</span>>GTK_ORIENTATION_HORIZONTAL</<span class="kw">property</span>></span> <span id="cb1-38"><a href="#cb1-38"></a> <<span class="kw">property</span><span class="ot"> name=</span><span class="st">"spacing"</span>>12</<span class="kw">property</span>></span> <span id="cb1-39"><a href="#cb1-39"></a> <<span class="kw">property</span><span class="ot"> name=</span><span class="st">"margin-top"</span>>12</<span class="kw">property</span>></span> <span id="cb1-40"><a href="#cb1-40"></a> <<span class="kw">property</span><span class="ot"> name=</span><span class="st">"margin-bottom"</span>>12</<span class="kw">property</span>></span> <span id="cb1-41"><a href="#cb1-41"></a> <<span class="kw">property</span><span class="ot"> name=</span><span class="st">"margin-start"</span>>12</<span class="kw">property</span>></span> <span id="cb1-42"><a href="#cb1-42"></a> <<span class="kw">property</span><span class="ot"> name=</span><span class="st">"margin-end"</span>>12</<span class="kw">property</span>></span> <span id="cb1-43"><a href="#cb1-43"></a> <<span class="kw">child</span>></span> <span id="cb1-44"><a href="#cb1-44"></a> <<span class="kw">object</span><span class="ot"> class=</span><span class="st">"GtkImage"</span>></span> <span id="cb1-45"><a href="#cb1-45"></a> <<span class="kw">property</span><span class="ot"> name=</span><span class="st">"icon-name"</span>>dialog-warning</<span class="kw">property</span>></span> <span id="cb1-46"><a href="#cb1-46"></a> <<span class="kw">property</span><span class="ot"> name=</span><span class="st">"icon-size"</span>>GTK_ICON_SIZE_LARGE</<span class="kw">property</span>></span> <span id="cb1-47"><a href="#cb1-47"></a> </<span class="kw">object</span>></span> <span id="cb1-48"><a href="#cb1-48"></a> </<span class="kw">child</span>></span> <span id="cb1-49"><a href="#cb1-49"></a> <<span class="kw">child</span>></span> <span id="cb1-50"><a href="#cb1-50"></a> <<span class="kw">object</span><span class="ot"> class=</span><span class="st">"GtkLabel"</span><span class="ot"> id=</span><span class="st">"lb_message"</span>></span> <span id="cb1-51"><a href="#cb1-51"></a> </<span class="kw">object</span>></span> <span id="cb1-52"><a href="#cb1-52"></a> </<span class="kw">child</span>></span> <span id="cb1-53"><a href="#cb1-53"></a> </<span class="kw">object</span>></span> <span id="cb1-54"><a href="#cb1-54"></a> </<span class="kw">child</span>></span> <span id="cb1-55"><a href="#cb1-55"></a> </<span class="kw">template</span>></span> <span id="cb1-56"><a href="#cb1-56"></a></<span class="kw">interface</span>></span></code></pre></div> <ul> <li>3: A template tag defines a composite widget. The class attribute tells the class name of the composite widget. The parent attribute tells the parent class of the composite widget. So, TfeAlert is a child class of GtkWindow. A parent attribute is an option and you can leave it out. But it is recommended to write it in the template tag.</li> <li>4-6: Its three properties are defined. These properties are inherited from GtkWindow. The titlebar property has a widget for a custom title bar. The typical widget is GtkHeaderBar.</li> <li>8: If the property “show-title-buttons” is TRUE, the title buttons like close, minimize and maximize are shown. Otherwise it is not shown. The TfeAlert object is not resizable. It is closed when either of the two buttons, cancel or accept, is clicked. Therefore the title buttons are not necessary and this property is set to FALSE.</li> <li>9-14: The bar has a title, which is a GtkLabel widget. The default title is “Are you sure?” but it can be replaced by an instance method.</li> <li>15-32: The bar has two buttons, cancel and accept. The cancel button is on the left so the child tag has <code>type="start"</code> attribute. The accept button is on the right so the child tag has <code>type="end"</code> attribute. The dialog is shown when the user clicked the close button or the quit menu without saving the data. Therefore, it is safer for the user to click on the cancel button of the alert dialog. So, the cancel button has a “suggested-action” CSS class. Ubuntu colors the button green but the color can be blue or other appropriate one defined by the system. In the same way the accept button has a “destructive-action” CSS class and is colored red. Two buttons have signals which are defined by the signal tags.</li> <li>35-54: A horizontal box has an image icon and a label.</li> <li>44-47: The GtkImage widget displays an image. The “icon-name” property is an icon name in the icon theme. The theme depends on your system. You can check it with an icon browser.</li> </ul> <pre><code>$ gtk4-icon-browser</code></pre> <p>The “dialog-warning” icon is something like this.</p> <figure> <img src="image/dialog_warning.png" alt="dialog-warning icon is like …" /> <figcaption aria-hidden="true">dialog-warning icon is like …</figcaption> </figure> <p>These are made by my hand. The real image on the alert dialog is nicer.</p> <p>It is possible to define the alert widget as a child of GtkDialog. But GtkDialog is deprecated since GTK version 4.10. And users should use GtkWindow instead of GtkDialog.</p> <h2 id="the-header-file">The header file</h2> <p>The header file is similar to the one of TfeTextView.</p> <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="pp">#pragma once</span></span> <span id="cb3-2"><a href="#cb3-2"></a></span> <span id="cb3-3"><a href="#cb3-3"></a><span class="pp">#include </span><span class="im"><gtk/gtk.h></span></span> <span id="cb3-4"><a href="#cb3-4"></a></span> <span id="cb3-5"><a href="#cb3-5"></a><span class="pp">#define TFE_TYPE_ALERT tfe_alert_get_type </span><span class="op">()</span></span> <span id="cb3-6"><a href="#cb3-6"></a>G_DECLARE_FINAL_TYPE <span class="op">(</span>TfeAlert<span class="op">,</span> tfe_alert<span class="op">,</span> TFE<span class="op">,</span> ALERT<span class="op">,</span> GtkWindow<span class="op">)</span></span> <span id="cb3-7"><a href="#cb3-7"></a></span> <span id="cb3-8"><a href="#cb3-8"></a><span class="co">/* "response" signal id */</span></span> <span id="cb3-9"><a href="#cb3-9"></a><span class="kw">enum</span> TfeAlertResponseType</span> <span id="cb3-10"><a href="#cb3-10"></a><span class="op">{</span></span> <span id="cb3-11"><a href="#cb3-11"></a> TFE_ALERT_RESPONSE_ACCEPT<span class="op">,</span></span> <span id="cb3-12"><a href="#cb3-12"></a> TFE_ALERT_RESPONSE_CANCEL</span> <span id="cb3-13"><a href="#cb3-13"></a><span class="op">};</span></span> <span id="cb3-14"><a href="#cb3-14"></a></span> <span id="cb3-15"><a href="#cb3-15"></a><span class="dt">const</span> <span class="dt">char</span> <span class="op">*</span></span> <span id="cb3-16"><a href="#cb3-16"></a>tfe_alert_get_title <span class="op">(</span>TfeAlert <span class="op">*</span>alert<span class="op">);</span></span> <span id="cb3-17"><a href="#cb3-17"></a></span> <span id="cb3-18"><a href="#cb3-18"></a><span class="dt">const</span> <span class="dt">char</span> <span class="op">*</span></span> <span id="cb3-19"><a href="#cb3-19"></a>tfe_alert_get_message <span class="op">(</span>TfeAlert <span class="op">*</span>alert<span class="op">);</span></span> <span id="cb3-20"><a href="#cb3-20"></a></span> <span id="cb3-21"><a href="#cb3-21"></a><span class="dt">const</span> <span class="dt">char</span> <span class="op">*</span></span> <span id="cb3-22"><a href="#cb3-22"></a>tfe_alert_get_button_label <span class="op">(</span>TfeAlert <span class="op">*</span>alert<span class="op">);</span></span> <span id="cb3-23"><a href="#cb3-23"></a></span> <span id="cb3-24"><a href="#cb3-24"></a><span class="dt">void</span></span> <span id="cb3-25"><a href="#cb3-25"></a>tfe_alert_set_title <span class="op">(</span>TfeAlert <span class="op">*</span>alert<span class="op">,</span> <span class="dt">const</span> <span class="dt">char</span> <span class="op">*</span>title<span class="op">);</span></span> <span id="cb3-26"><a href="#cb3-26"></a></span> <span id="cb3-27"><a href="#cb3-27"></a><span class="dt">void</span></span> <span id="cb3-28"><a href="#cb3-28"></a>tfe_alert_set_message <span class="op">(</span>TfeAlert <span class="op">*</span>alert<span class="op">,</span> <span class="dt">const</span> <span class="dt">char</span> <span class="op">*</span>message<span class="op">);</span></span> <span id="cb3-29"><a href="#cb3-29"></a></span> <span id="cb3-30"><a href="#cb3-30"></a><span class="dt">void</span></span> <span id="cb3-31"><a href="#cb3-31"></a>tfe_alert_set_button_label <span class="op">(</span>TfeAlert <span class="op">*</span>alert<span class="op">,</span> <span class="dt">const</span> <span class="dt">char</span> <span class="op">*</span>btn_label<span class="op">);</span></span> <span id="cb3-32"><a href="#cb3-32"></a></span> <span id="cb3-33"><a href="#cb3-33"></a>GtkWidget <span class="op">*</span></span> <span id="cb3-34"><a href="#cb3-34"></a>tfe_alert_new <span class="op">(</span><span class="dt">void</span><span class="op">);</span></span> <span id="cb3-35"><a href="#cb3-35"></a></span> <span id="cb3-36"><a href="#cb3-36"></a>GtkWidget <span class="op">*</span></span> <span id="cb3-37"><a href="#cb3-37"></a>tfe_alert_new_with_data <span class="op">(</span><span class="dt">const</span> <span class="dt">char</span> <span class="op">*</span>title<span class="op">,</span> <span class="dt">const</span> <span class="dt">char</span> <span class="op">*</span>message<span class="op">,</span> <span class="dt">const</span> <span class="dt">char</span><span class="op">*</span> btn_label<span class="op">);</span></span></code></pre></div> <ul> <li>5-6: These two lines are always needed to define a new object. <code>TFE_TYPE_ALERT</code> is the type of TfeAlert object and it is a macro expanded into <code>tfe_alert_get_type ()</code>. G_DECLARE_FINAL_TYPE macro is expanded into: <ul> <li>The declaration of the function <code>tfe_alert_get_type</code></li> <li><code>TfeAlert</code> is defined as a typedef of <code>struct _TfeAlert</code>, which is defined in the C file.</li> <li><code>TFE_ALERT</code> and <code>TFE_IS_ALERT</code> macro is defined as a cast and type check function.</li> <li><code>TfeAlertClass</code> structure is defined as a final class.</li> </ul></li> <li>8-13: The TfeAlert class has a “response” signal. It has a parameter and the parameter type is defined as a <code>TfeAlertResponseType</code> enumerative constant.</li> <li>15-31: Getter and setter methods.</li> <li>33-37: Functions to create a instance. The function <code>tfe_alert_new_with_data</code> is a convenience function, which creates an instance and sets data at once.</li> </ul> <h2 id="the-c-file">The C file</h2> <h3 id="functions-for-composite-widgets">Functions for composite widgets</h3> <p>The following codes are extracted from <code>tfealert.c</code>.</p> <div class="sourceCode" id="cb4"><pre class="sourceCode C"><code class="sourceCode c"><span id="cb4-1"><a href="#cb4-1" aria-hidden="true" tabindex="-1"></a><span class="pp">#include </span><span class="im"><gtk/gtk.h></span></span> <span id="cb4-2"><a href="#cb4-2" aria-hidden="true" tabindex="-1"></a><span class="pp">#include </span><span class="im">"tfealert.h"</span></span> <span id="cb4-3"><a href="#cb4-3" aria-hidden="true" tabindex="-1"></a></span> <span id="cb4-4"><a href="#cb4-4" aria-hidden="true" tabindex="-1"></a><span class="kw">struct</span> _TfeAlert <span class="op">{</span></span> <span id="cb4-5"><a href="#cb4-5" aria-hidden="true" tabindex="-1"></a> GtkWindow parent<span class="op">;</span></span> <span id="cb4-6"><a href="#cb4-6" aria-hidden="true" tabindex="-1"></a> GtkLabel <span class="op">*</span>lb_title<span class="op">;</span></span> <span id="cb4-7"><a href="#cb4-7" aria-hidden="true" tabindex="-1"></a> GtkLabel <span class="op">*</span>lb_message<span class="op">;</span></span> <span id="cb4-8"><a href="#cb4-8" aria-hidden="true" tabindex="-1"></a> GtkButton <span class="op">*</span>btn_accept<span class="op">;</span></span> <span id="cb4-9"><a href="#cb4-9" aria-hidden="true" tabindex="-1"></a> GtkButton <span class="op">*</span>btn_cancel<span class="op">;</span></span> <span id="cb4-10"><a href="#cb4-10" aria-hidden="true" tabindex="-1"></a><span class="op">};</span></span> <span id="cb4-11"><a href="#cb4-11" aria-hidden="true" tabindex="-1"></a></span> <span id="cb4-12"><a href="#cb4-12" aria-hidden="true" tabindex="-1"></a>G_DEFINE_FINAL_TYPE <span class="op">(</span>TfeAlert<span class="op">,</span> tfe_alert<span class="op">,</span> GTK_TYPE_WINDOW<span class="op">);</span></span> <span id="cb4-13"><a href="#cb4-13" aria-hidden="true" tabindex="-1"></a></span> <span id="cb4-14"><a href="#cb4-14" aria-hidden="true" tabindex="-1"></a><span class="dt">static</span> <span class="dt">void</span></span> <span id="cb4-15"><a href="#cb4-15" aria-hidden="true" tabindex="-1"></a>cancel_cb <span class="op">(</span>TfeAlert <span class="op">*</span>alert<span class="op">)</span> <span class="op">{</span></span> <span id="cb4-16"><a href="#cb4-16" aria-hidden="true" tabindex="-1"></a> <span class="op">...</span> <span class="op">...</span> <span class="op">...</span></span> <span id="cb4-17"><a href="#cb4-17" aria-hidden="true" tabindex="-1"></a><span class="op">}</span></span> <span id="cb4-18"><a href="#cb4-18" aria-hidden="true" tabindex="-1"></a></span> <span id="cb4-19"><a href="#cb4-19" aria-hidden="true" tabindex="-1"></a><span class="dt">static</span> <span class="dt">void</span></span> <span id="cb4-20"><a href="#cb4-20" aria-hidden="true" tabindex="-1"></a>accept_cb <span class="op">(</span>TfeAlert <span class="op">*</span>alert<span class="op">)</span> <span class="op">{</span></span> <span id="cb4-21"><a href="#cb4-21" aria-hidden="true" tabindex="-1"></a> <span class="op">...</span> <span class="op">...</span> <span class="op">...</span></span> <span id="cb4-22"><a href="#cb4-22" aria-hidden="true" tabindex="-1"></a><span class="op">}</span></span> <span id="cb4-23"><a href="#cb4-23" aria-hidden="true" tabindex="-1"></a></span> <span id="cb4-24"><a href="#cb4-24" aria-hidden="true" tabindex="-1"></a><span class="dt">static</span> <span class="dt">void</span></span> <span id="cb4-25"><a href="#cb4-25" aria-hidden="true" tabindex="-1"></a>tfe_alert_dispose <span class="op">(</span>GObject <span class="op">*</span>gobject<span class="op">)</span> <span class="op">{</span> <span class="co">// gobject is actually a TfeAlert instance.</span></span> <span id="cb4-26"><a href="#cb4-26" aria-hidden="true" tabindex="-1"></a> gtk_widget_dispose_template <span class="op">(</span>GTK_WIDGET <span class="op">(</span>gobject<span class="op">),</span> TFE_TYPE_ALERT<span class="op">);</span></span> <span id="cb4-27"><a href="#cb4-27" aria-hidden="true" tabindex="-1"></a> G_OBJECT_CLASS <span class="op">(</span>tfe_alert_parent_class<span class="op">)-></span>dispose <span class="op">(</span>gobject<span class="op">);</span></span> <span id="cb4-28"><a href="#cb4-28" aria-hidden="true" tabindex="-1"></a><span class="op">}</span></span> <span id="cb4-29"><a href="#cb4-29" aria-hidden="true" tabindex="-1"></a></span> <span id="cb4-30"><a href="#cb4-30" aria-hidden="true" tabindex="-1"></a><span class="dt">static</span> <span class="dt">void</span></span> <span id="cb4-31"><a href="#cb4-31" aria-hidden="true" tabindex="-1"></a>tfe_alert_init <span class="op">(</span>TfeAlert <span class="op">*</span>alert<span class="op">)</span> <span class="op">{</span></span> <span id="cb4-32"><a href="#cb4-32" aria-hidden="true" tabindex="-1"></a> gtk_widget_init_template <span class="op">(</span>GTK_WIDGET <span class="op">(</span>alert<span class="op">));</span></span> <span id="cb4-33"><a href="#cb4-33" aria-hidden="true" tabindex="-1"></a><span class="op">}</span></span> <span id="cb4-34"><a href="#cb4-34" aria-hidden="true" tabindex="-1"></a></span> <span id="cb4-35"><a href="#cb4-35" aria-hidden="true" tabindex="-1"></a><span class="dt">static</span> <span class="dt">void</span></span> <span id="cb4-36"><a href="#cb4-36" aria-hidden="true" tabindex="-1"></a>tfe_alert_class_init <span class="op">(</span>TfeAlertClass <span class="op">*</span>class<span class="op">)</span> <span class="op">{</span></span> <span id="cb4-37"><a href="#cb4-37" aria-hidden="true" tabindex="-1"></a> G_OBJECT_CLASS <span class="op">(</span>class<span class="op">)-></span>dispose <span class="op">=</span> tfe_alert_dispose<span class="op">;</span></span> <span id="cb4-38"><a href="#cb4-38" aria-hidden="true" tabindex="-1"></a> gtk_widget_class_set_template_from_resource <span class="op">(</span>GTK_WIDGET_CLASS <span class="op">(</span>class<span class="op">),</span> <span class="st">"/com/github/ToshioCP/tfe/tfealert.ui"</span><span class="op">);</span></span> <span id="cb4-39"><a href="#cb4-39" aria-hidden="true" tabindex="-1"></a> gtk_widget_class_bind_template_child <span class="op">(</span>GTK_WIDGET_CLASS <span class="op">(</span>class<span class="op">),</span> TfeAlert<span class="op">,</span> lb_title<span class="op">);</span></span> <span id="cb4-40"><a href="#cb4-40" aria-hidden="true" tabindex="-1"></a> gtk_widget_class_bind_template_child <span class="op">(</span>GTK_WIDGET_CLASS <span class="op">(</span>class<span class="op">),</span> TfeAlert<span class="op">,</span> lb_message<span class="op">);</span></span> <span id="cb4-41"><a href="#cb4-41" aria-hidden="true" tabindex="-1"></a> gtk_widget_class_bind_template_child <span class="op">(</span>GTK_WIDGET_CLASS <span class="op">(</span>class<span class="op">),</span> TfeAlert<span class="op">,</span> btn_accept<span class="op">);</span></span> <span id="cb4-42"><a href="#cb4-42" aria-hidden="true" tabindex="-1"></a> gtk_widget_class_bind_template_child <span class="op">(</span>GTK_WIDGET_CLASS <span class="op">(</span>class<span class="op">),</span> TfeAlert<span class="op">,</span> btn_cancel<span class="op">);</span></span> <span id="cb4-43"><a href="#cb4-43" aria-hidden="true" tabindex="-1"></a> gtk_widget_class_bind_template_callback <span class="op">(</span>GTK_WIDGET_CLASS <span class="op">(</span>class<span class="op">),</span> cancel_cb<span class="op">);</span></span> <span id="cb4-44"><a href="#cb4-44" aria-hidden="true" tabindex="-1"></a> gtk_widget_class_bind_template_callback <span class="op">(</span>GTK_WIDGET_CLASS <span class="op">(</span>class<span class="op">),</span> accept_cb<span class="op">);</span></span> <span id="cb4-45"><a href="#cb4-45" aria-hidden="true" tabindex="-1"></a> <span class="op">...</span> <span class="op">...</span> <span class="op">...</span></span> <span id="cb4-46"><a href="#cb4-46" aria-hidden="true" tabindex="-1"></a><span class="op">}</span></span> <span id="cb4-47"><a href="#cb4-47" aria-hidden="true" tabindex="-1"></a></span> <span id="cb4-48"><a href="#cb4-48" aria-hidden="true" tabindex="-1"></a>GtkWidget <span class="op">*</span></span> <span id="cb4-49"><a href="#cb4-49" aria-hidden="true" tabindex="-1"></a>tfe_alert_new <span class="op">(</span><span class="dt">void</span><span class="op">)</span> <span class="op">{</span></span> <span id="cb4-50"><a href="#cb4-50" aria-hidden="true" tabindex="-1"></a> <span class="cf">return</span> GTK_WIDGET <span class="op">(</span>g_object_new <span class="op">(</span>TFE_TYPE_ALERT<span class="op">,</span> NULL<span class="op">));</span></span> <span id="cb4-51"><a href="#cb4-51" aria-hidden="true" tabindex="-1"></a><span class="op">}</span></span></code></pre></div> <ul> <li>The macro <code>G_DEFINE_FINAL_TYPE</code> is available since GLib version 2.70. It is used only for a final type class. You can use <code>G_DEFINE_TYPE</code> macro instead. They are expanded into: <ul> <li>The declaration of the functions <code>tfe_alert_init</code> and <code>tfe_alert_class_init</code>. They are defined in the following part of the C program.</li> <li>The definition of the variable <code>tfe_alert_parent_class</code>.</li> <li>The definition of the function <code>tfe_alert_get_type</code>.</li> </ul></li> <li>The names of the members of <code>_TfeAlert</code>, which are <code>lb_title</code>, <code>lb_message</code>, <code>btn_accept</code> and <code>btn_cancel</code>, must be the same as the id attribute in the XML file <code>tfealert.ui</code>.</li> <li>The function <code>tfe_alert_class_init</code> initializes the composite widget class. <ul> <li>The function <code>gtk_widget_class_set_template_from_resource</code> sets the template of the class. The template is built from the XML resource “tfealert.ui”. At this moment no instance is created. It just makes the class recognize the structure of the object. That’s why the top level tag is not object but template in the XML file.</li> <li>The function macro <code>gtk_widget_class_bind_template_child</code> connects the member of TfeAlert and the object class in the template. So, for example, you can access to <code>lb_title</code> GtkLabel instance via <code>alert->lb_title</code> where <code>alert</code> is an instance of TfeAlert class.</li> <li>The function <code>gtk_widget_class_bind_template_callback</code> connects the callback function and the <code>handler</code> attribute of the signal tag in the XML. For example, the “clicked” signal on the cancel button has a handler named “cancel_cb” in the signal tag. And the function <code>cancel_cb</code> exists in the C file above. These two are connected so when the signal is emitted the function <code>cancel_cb</code> is called. You can add <code>static</code> storage class to the callback function thanks to this connection.</li> </ul></li> <li>The function <code>tfe_alert_init</code> initializes the newly created instance. You need to call <code>gtk_widget_init_template</code> to create and initialize the child widgets in the template.</li> <li>The function <code>tfe_alert_despose</code> releases objects. The function <code>gtk_widget_despose_template</code> clears the template children.</li> <li>The function <code>tfe_alert_new</code> creates the composite widget TfeAlert instance. It creates not only TfeAlert itself but also all the child widgets that the composite widget has.</li> </ul> <h3 id="other-functions">Other functions</h3> <p>The following is the full codes of <code>tfealert.c</code>.</p> <div class="sourceCode" id="cb5"><pre class="sourceCode numberSource C numberLines"><code class="sourceCode c"><span id="cb5-1"><a href="#cb5-1"></a><span class="pp">#include </span><span class="im"><gtk/gtk.h></span></span> <span id="cb5-2"><a href="#cb5-2"></a><span class="pp">#include </span><span class="im">"tfealert.h"</span></span> <span id="cb5-3"><a href="#cb5-3"></a></span> <span id="cb5-4"><a href="#cb5-4"></a><span class="kw">struct</span> _TfeAlert <span class="op">{</span></span> <span id="cb5-5"><a href="#cb5-5"></a> GtkWindow parent<span class="op">;</span></span> <span id="cb5-6"><a href="#cb5-6"></a> GtkLabel <span class="op">*</span>lb_title<span class="op">;</span></span> <span id="cb5-7"><a href="#cb5-7"></a> GtkLabel <span class="op">*</span>lb_message<span class="op">;</span></span> <span id="cb5-8"><a href="#cb5-8"></a> GtkButton <span class="op">*</span>btn_accept<span class="op">;</span></span> <span id="cb5-9"><a href="#cb5-9"></a> GtkButton <span class="op">*</span>btn_cancel<span class="op">;</span></span> <span id="cb5-10"><a href="#cb5-10"></a><span class="op">};</span></span> <span id="cb5-11"><a href="#cb5-11"></a></span> <span id="cb5-12"><a href="#cb5-12"></a>G_DEFINE_FINAL_TYPE <span class="op">(</span>TfeAlert<span class="op">,</span> tfe_alert<span class="op">,</span> GTK_TYPE_WINDOW<span class="op">);</span></span> <span id="cb5-13"><a href="#cb5-13"></a></span> <span id="cb5-14"><a href="#cb5-14"></a><span class="kw">enum</span> <span class="op">{</span></span> <span id="cb5-15"><a href="#cb5-15"></a> RESPONSE<span class="op">,</span></span> <span id="cb5-16"><a href="#cb5-16"></a> NUMBER_OF_SIGNALS</span> <span id="cb5-17"><a href="#cb5-17"></a><span class="op">};</span></span> <span id="cb5-18"><a href="#cb5-18"></a></span> <span id="cb5-19"><a href="#cb5-19"></a><span class="dt">static</span> guint tfe_alert_signals<span class="op">[</span>NUMBER_OF_SIGNALS<span class="op">];</span></span> <span id="cb5-20"><a href="#cb5-20"></a></span> <span id="cb5-21"><a href="#cb5-21"></a><span class="dt">static</span> <span class="dt">void</span></span> <span id="cb5-22"><a href="#cb5-22"></a>cancel_cb <span class="op">(</span>TfeAlert <span class="op">*</span>alert<span class="op">)</span> <span class="op">{</span></span> <span id="cb5-23"><a href="#cb5-23"></a> g_signal_emit <span class="op">(</span>alert<span class="op">,</span> tfe_alert_signals<span class="op">[</span>RESPONSE<span class="op">],</span> <span class="dv">0</span><span class="op">,</span> TFE_ALERT_RESPONSE_CANCEL<span class="op">);</span></span> <span id="cb5-24"><a href="#cb5-24"></a> gtk_window_destroy <span class="op">(</span>GTK_WINDOW <span class="op">(</span>alert<span class="op">));</span></span> <span id="cb5-25"><a href="#cb5-25"></a><span class="op">}</span></span> <span id="cb5-26"><a href="#cb5-26"></a></span> <span id="cb5-27"><a href="#cb5-27"></a><span class="dt">static</span> <span class="dt">void</span></span> <span id="cb5-28"><a href="#cb5-28"></a>accept_cb <span class="op">(</span>TfeAlert <span class="op">*</span>alert<span class="op">)</span> <span class="op">{</span></span> <span id="cb5-29"><a href="#cb5-29"></a> g_signal_emit <span class="op">(</span>alert<span class="op">,</span> tfe_alert_signals<span class="op">[</span>RESPONSE<span class="op">],</span> <span class="dv">0</span><span class="op">,</span> TFE_ALERT_RESPONSE_ACCEPT<span class="op">);</span></span> <span id="cb5-30"><a href="#cb5-30"></a> gtk_window_destroy <span class="op">(</span>GTK_WINDOW <span class="op">(</span>alert<span class="op">));</span></span> <span id="cb5-31"><a href="#cb5-31"></a><span class="op">}</span></span> <span id="cb5-32"><a href="#cb5-32"></a></span> <span id="cb5-33"><a href="#cb5-33"></a><span class="dt">const</span> <span class="dt">char</span> <span class="op">*</span></span> <span id="cb5-34"><a href="#cb5-34"></a>tfe_alert_get_title <span class="op">(</span>TfeAlert <span class="op">*</span>alert<span class="op">)</span> <span class="op">{</span></span> <span id="cb5-35"><a href="#cb5-35"></a> <span class="cf">return</span> gtk_label_get_text <span class="op">(</span>alert<span class="op">-></span>lb_title<span class="op">);</span></span> <span id="cb5-36"><a href="#cb5-36"></a><span class="op">}</span></span> <span id="cb5-37"><a href="#cb5-37"></a></span> <span id="cb5-38"><a href="#cb5-38"></a><span class="dt">const</span> <span class="dt">char</span> <span class="op">*</span></span> <span id="cb5-39"><a href="#cb5-39"></a>tfe_alert_get_message <span class="op">(</span>TfeAlert <span class="op">*</span>alert<span class="op">)</span> <span class="op">{</span></span> <span id="cb5-40"><a href="#cb5-40"></a> <span class="cf">return</span> gtk_label_get_text <span class="op">(</span>alert<span class="op">-></span>lb_message<span class="op">);</span></span> <span id="cb5-41"><a href="#cb5-41"></a><span class="op">}</span></span> <span id="cb5-42"><a href="#cb5-42"></a></span> <span id="cb5-43"><a href="#cb5-43"></a><span class="dt">const</span> <span class="dt">char</span> <span class="op">*</span></span> <span id="cb5-44"><a href="#cb5-44"></a>tfe_alert_get_button_label <span class="op">(</span>TfeAlert <span class="op">*</span>alert<span class="op">)</span> <span class="op">{</span></span> <span id="cb5-45"><a href="#cb5-45"></a> <span class="cf">return</span> gtk_button_get_label <span class="op">(</span>alert<span class="op">-></span>btn_accept<span class="op">);</span></span> <span id="cb5-46"><a href="#cb5-46"></a><span class="op">}</span></span> <span id="cb5-47"><a href="#cb5-47"></a></span> <span id="cb5-48"><a href="#cb5-48"></a><span class="dt">void</span></span> <span id="cb5-49"><a href="#cb5-49"></a>tfe_alert_set_title <span class="op">(</span>TfeAlert <span class="op">*</span>alert<span class="op">,</span> <span class="dt">const</span> <span class="dt">char</span> <span class="op">*</span>title<span class="op">)</span> <span class="op">{</span></span> <span id="cb5-50"><a href="#cb5-50"></a> gtk_label_set_text <span class="op">(</span>alert<span class="op">-></span>lb_title<span class="op">,</span> title<span class="op">);</span></span> <span id="cb5-51"><a href="#cb5-51"></a><span class="op">}</span></span> <span id="cb5-52"><a href="#cb5-52"></a></span> <span id="cb5-53"><a href="#cb5-53"></a><span class="dt">void</span></span> <span id="cb5-54"><a href="#cb5-54"></a>tfe_alert_set_message <span class="op">(</span>TfeAlert <span class="op">*</span>alert<span class="op">,</span> <span class="dt">const</span> <span class="dt">char</span> <span class="op">*</span>message<span class="op">)</span> <span class="op">{</span></span> <span id="cb5-55"><a href="#cb5-55"></a> gtk_label_set_text <span class="op">(</span>alert<span class="op">-></span>lb_message<span class="op">,</span> message<span class="op">);</span></span> <span id="cb5-56"><a href="#cb5-56"></a><span class="op">}</span></span> <span id="cb5-57"><a href="#cb5-57"></a></span> <span id="cb5-58"><a href="#cb5-58"></a><span class="dt">void</span></span> <span id="cb5-59"><a href="#cb5-59"></a>tfe_alert_set_button_label <span class="op">(</span>TfeAlert <span class="op">*</span>alert<span class="op">,</span> <span class="dt">const</span> <span class="dt">char</span> <span class="op">*</span>btn_label<span class="op">)</span> <span class="op">{</span></span> <span id="cb5-60"><a href="#cb5-60"></a> gtk_button_set_label <span class="op">(</span>alert<span class="op">-></span>btn_accept<span class="op">,</span> btn_label<span class="op">);</span></span> <span id="cb5-61"><a href="#cb5-61"></a><span class="op">}</span></span> <span id="cb5-62"><a href="#cb5-62"></a></span> <span id="cb5-63"><a href="#cb5-63"></a><span class="dt">static</span> <span class="dt">void</span></span> <span id="cb5-64"><a href="#cb5-64"></a>tfe_alert_dispose <span class="op">(</span>GObject <span class="op">*</span>gobject<span class="op">)</span> <span class="op">{</span> <span class="co">// gobject is actually a TfeAlert instance.</span></span> <span id="cb5-65"><a href="#cb5-65"></a> gtk_widget_dispose_template <span class="op">(</span>GTK_WIDGET <span class="op">(</span>gobject<span class="op">),</span> TFE_TYPE_ALERT<span class="op">);</span></span> <span id="cb5-66"><a href="#cb5-66"></a> G_OBJECT_CLASS <span class="op">(</span>tfe_alert_parent_class<span class="op">)-></span>dispose <span class="op">(</span>gobject<span class="op">);</span></span> <span id="cb5-67"><a href="#cb5-67"></a><span class="op">}</span></span> <span id="cb5-68"><a href="#cb5-68"></a></span> <span id="cb5-69"><a href="#cb5-69"></a><span class="dt">static</span> <span class="dt">void</span></span> <span id="cb5-70"><a href="#cb5-70"></a>tfe_alert_init <span class="op">(</span>TfeAlert <span class="op">*</span>alert<span class="op">)</span> <span class="op">{</span></span> <span id="cb5-71"><a href="#cb5-71"></a> gtk_widget_init_template <span class="op">(</span>GTK_WIDGET <span class="op">(</span>alert<span class="op">));</span></span> <span id="cb5-72"><a href="#cb5-72"></a><span class="op">}</span></span> <span id="cb5-73"><a href="#cb5-73"></a></span> <span id="cb5-74"><a href="#cb5-74"></a><span class="dt">static</span> <span class="dt">void</span></span> <span id="cb5-75"><a href="#cb5-75"></a>tfe_alert_class_init <span class="op">(</span>TfeAlertClass <span class="op">*</span>class<span class="op">)</span> <span class="op">{</span></span> <span id="cb5-76"><a href="#cb5-76"></a> G_OBJECT_CLASS <span class="op">(</span>class<span class="op">)-></span>dispose <span class="op">=</span> tfe_alert_dispose<span class="op">;</span></span> <span id="cb5-77"><a href="#cb5-77"></a> gtk_widget_class_set_template_from_resource <span class="op">(</span>GTK_WIDGET_CLASS <span class="op">(</span>class<span class="op">),</span> <span class="st">"/com/github/ToshioCP/tfe/tfealert.ui"</span><span class="op">);</span></span> <span id="cb5-78"><a href="#cb5-78"></a> gtk_widget_class_bind_template_child <span class="op">(</span>GTK_WIDGET_CLASS <span class="op">(</span>class<span class="op">),</span> TfeAlert<span class="op">,</span> lb_title<span class="op">);</span></span> <span id="cb5-79"><a href="#cb5-79"></a> gtk_widget_class_bind_template_child <span class="op">(</span>GTK_WIDGET_CLASS <span class="op">(</span>class<span class="op">),</span> TfeAlert<span class="op">,</span> lb_message<span class="op">);</span></span> <span id="cb5-80"><a href="#cb5-80"></a> gtk_widget_class_bind_template_child <span class="op">(</span>GTK_WIDGET_CLASS <span class="op">(</span>class<span class="op">),</span> TfeAlert<span class="op">,</span> btn_accept<span class="op">);</span></span> <span id="cb5-81"><a href="#cb5-81"></a> gtk_widget_class_bind_template_child <span class="op">(</span>GTK_WIDGET_CLASS <span class="op">(</span>class<span class="op">),</span> TfeAlert<span class="op">,</span> btn_cancel<span class="op">);</span></span> <span id="cb5-82"><a href="#cb5-82"></a> gtk_widget_class_bind_template_callback <span class="op">(</span>GTK_WIDGET_CLASS <span class="op">(</span>class<span class="op">),</span> cancel_cb<span class="op">);</span></span> <span id="cb5-83"><a href="#cb5-83"></a> gtk_widget_class_bind_template_callback <span class="op">(</span>GTK_WIDGET_CLASS <span class="op">(</span>class<span class="op">),</span> accept_cb<span class="op">);</span></span> <span id="cb5-84"><a href="#cb5-84"></a></span> <span id="cb5-85"><a href="#cb5-85"></a> tfe_alert_signals<span class="op">[</span>RESPONSE<span class="op">]</span> <span class="op">=</span> g_signal_new <span class="op">(</span><span class="st">"response"</span><span class="op">,</span></span> <span id="cb5-86"><a href="#cb5-86"></a> G_TYPE_FROM_CLASS <span class="op">(</span>class<span class="op">),</span></span> <span id="cb5-87"><a href="#cb5-87"></a> G_SIGNAL_RUN_LAST <span class="op">|</span> G_SIGNAL_NO_RECURSE <span class="op">|</span> G_SIGNAL_NO_HOOKS<span class="op">,</span></span> <span id="cb5-88"><a href="#cb5-88"></a> <span class="dv">0</span> <span class="co">/* class offset */</span><span class="op">,</span></span> <span id="cb5-89"><a href="#cb5-89"></a> NULL <span class="co">/* accumulator */</span><span class="op">,</span></span> <span id="cb5-90"><a href="#cb5-90"></a> NULL <span class="co">/* accumulator data */</span><span class="op">,</span></span> <span id="cb5-91"><a href="#cb5-91"></a> NULL <span class="co">/* C marshaller */</span><span class="op">,</span></span> <span id="cb5-92"><a href="#cb5-92"></a> G_TYPE_NONE <span class="co">/* return_type */</span><span class="op">,</span></span> <span id="cb5-93"><a href="#cb5-93"></a> <span class="dv">1</span> <span class="co">/* n_params */</span><span class="op">,</span></span> <span id="cb5-94"><a href="#cb5-94"></a> G_TYPE_INT</span> <span id="cb5-95"><a href="#cb5-95"></a> <span class="op">);</span></span> <span id="cb5-96"><a href="#cb5-96"></a><span class="op">}</span></span> <span id="cb5-97"><a href="#cb5-97"></a></span> <span id="cb5-98"><a href="#cb5-98"></a>GtkWidget <span class="op">*</span></span> <span id="cb5-99"><a href="#cb5-99"></a>tfe_alert_new <span class="op">(</span><span class="dt">void</span><span class="op">)</span> <span class="op">{</span></span> <span id="cb5-100"><a href="#cb5-100"></a> <span class="cf">return</span> GTK_WIDGET <span class="op">(</span>g_object_new <span class="op">(</span>TFE_TYPE_ALERT<span class="op">,</span> NULL<span class="op">));</span></span> <span id="cb5-101"><a href="#cb5-101"></a><span class="op">}</span></span> <span id="cb5-102"><a href="#cb5-102"></a></span> <span id="cb5-103"><a href="#cb5-103"></a>GtkWidget <span class="op">*</span></span> <span id="cb5-104"><a href="#cb5-104"></a>tfe_alert_new_with_data <span class="op">(</span><span class="dt">const</span> <span class="dt">char</span> <span class="op">*</span>title<span class="op">,</span> <span class="dt">const</span> <span class="dt">char</span> <span class="op">*</span>message<span class="op">,</span> <span class="dt">const</span> <span class="dt">char</span><span class="op">*</span> btn_label<span class="op">)</span> <span class="op">{</span></span> <span id="cb5-105"><a href="#cb5-105"></a> GtkWidget <span class="op">*</span>alert <span class="op">=</span> tfe_alert_new <span class="op">();</span></span> <span id="cb5-106"><a href="#cb5-106"></a> tfe_alert_set_title <span class="op">(</span>TFE_ALERT <span class="op">(</span>alert<span class="op">),</span> title<span class="op">);</span></span> <span id="cb5-107"><a href="#cb5-107"></a> tfe_alert_set_message <span class="op">(</span>TFE_ALERT <span class="op">(</span>alert<span class="op">),</span> message<span class="op">);</span></span> <span id="cb5-108"><a href="#cb5-108"></a> tfe_alert_set_button_label <span class="op">(</span>TFE_ALERT <span class="op">(</span>alert<span class="op">),</span> btn_label<span class="op">);</span></span> <span id="cb5-109"><a href="#cb5-109"></a> <span class="cf">return</span> alert<span class="op">;</span></span> <span id="cb5-110"><a href="#cb5-110"></a><span class="op">}</span></span></code></pre></div> <p>The function <code>tfe_alert_new_with_data</code> is used more often than <code>tfe_alert_new</code> to create a new instance. It creates the instance and sets three data at the same time. The following is the common process when you use the TfeAlert class.</p> <ul> <li>Call <code>tfe_alert_new_with_data</code> and create an instance.</li> <li>Call <code>gtk_window_set_transient_for</code> to set the transient parent window.</li> <li>Call <code>gtk_window_present</code> to show the TfeAlert dialog.</li> <li>Connect “response” signal and a handler.</li> <li>The user clicks on the cancel or accept button. Then the dialog emits the “response” signal and destroy itself.</li> <li>The user catches the signal and do something.</li> </ul> <p>The rest of the program is:</p> <ul> <li>14-19: An array for a signal id. You can use a variable instead of an array because the class has only one signal. But using an array is a common way.</li> <li>21-31: Signal handlers. They emits the “response” signal and destroy the instance itself.</li> <li>33-61: Getters and setters.</li> <li>85-95: Creates the “response” signal.</li> <li>103-110: A convenience function <code>tfe_alert_new_with_data</code> creates an instance and sets labels.</li> </ul> <h2 id="an-example">An example</h2> <p>There’s an example in the <code>src/tfe6/example</code> directory. It shows how to use TfeAlert. The program is <code>src/example/ex_alert.c</code>.</p> <div class="sourceCode" id="cb6"><pre class="sourceCode numberSource C numberLines"><code class="sourceCode c"><span id="cb6-1"><a href="#cb6-1"></a><span class="pp">#include </span><span class="im"><gtk/gtk.h></span></span> <span id="cb6-2"><a href="#cb6-2"></a><span class="pp">#include </span><span class="im">"../tfealert.h"</span></span> <span id="cb6-3"><a href="#cb6-3"></a></span> <span id="cb6-4"><a href="#cb6-4"></a><span class="dt">static</span> <span class="dt">void</span></span> <span id="cb6-5"><a href="#cb6-5"></a>alert_response_cb <span class="op">(</span>TfeAlert <span class="op">*</span>alert<span class="op">,</span> <span class="dt">int</span> response<span class="op">,</span> gpointer user_data<span class="op">)</span> <span class="op">{</span></span> <span id="cb6-6"><a href="#cb6-6"></a> <span class="cf">if</span> <span class="op">(</span>response <span class="op">==</span> TFE_ALERT_RESPONSE_ACCEPT<span class="op">)</span></span> <span id="cb6-7"><a href="#cb6-7"></a> g_print <span class="op">(</span><span class="st">"</span><span class="sc">%s\n</span><span class="st">"</span><span class="op">,</span> tfe_alert_get_button_label <span class="op">(</span>alert<span class="op">));</span></span> <span id="cb6-8"><a href="#cb6-8"></a> <span class="cf">else</span> <span class="cf">if</span> <span class="op">(</span>response <span class="op">==</span> TFE_ALERT_RESPONSE_CANCEL<span class="op">)</span></span> <span id="cb6-9"><a href="#cb6-9"></a> g_print <span class="op">(</span><span class="st">"Cancel</span><span class="sc">\n</span><span class="st">"</span><span class="op">);</span></span> <span id="cb6-10"><a href="#cb6-10"></a> <span class="cf">else</span></span> <span id="cb6-11"><a href="#cb6-11"></a> g_print <span class="op">(</span><span class="st">"Unexpected error</span><span class="sc">\n</span><span class="st">"</span><span class="op">);</span></span> <span id="cb6-12"><a href="#cb6-12"></a><span class="op">}</span></span> <span id="cb6-13"><a href="#cb6-13"></a></span> <span id="cb6-14"><a href="#cb6-14"></a><span class="dt">static</span> <span class="dt">void</span></span> <span id="cb6-15"><a href="#cb6-15"></a>app_activate <span class="op">(</span>GApplication <span class="op">*</span>application<span class="op">)</span> <span class="op">{</span></span> <span id="cb6-16"><a href="#cb6-16"></a> GtkWidget <span class="op">*</span>alert<span class="op">;</span></span> <span id="cb6-17"><a href="#cb6-17"></a> <span class="dt">char</span> <span class="op">*</span>title<span class="op">,</span> <span class="op">*</span>message<span class="op">,</span> <span class="op">*</span>btn_label<span class="op">;</span></span> <span id="cb6-18"><a href="#cb6-18"></a></span> <span id="cb6-19"><a href="#cb6-19"></a> title <span class="op">=</span> <span class="st">"Example for TfeAlert"</span><span class="op">;</span> message <span class="op">=</span> <span class="st">"Click on Cancel or Accept button"</span><span class="op">;</span> btn_label <span class="op">=</span> <span class="st">"Accept"</span><span class="op">;</span></span> <span id="cb6-20"><a href="#cb6-20"></a> alert <span class="op">=</span> tfe_alert_new_with_data <span class="op">(</span>title<span class="op">,</span> message<span class="op">,</span> btn_label<span class="op">);</span></span> <span id="cb6-21"><a href="#cb6-21"></a> g_signal_connect <span class="op">(</span>TFE_ALERT <span class="op">(</span>alert<span class="op">),</span> <span class="st">"response"</span><span class="op">,</span> G_CALLBACK <span class="op">(</span>alert_response_cb<span class="op">),</span> NULL<span class="op">);</span></span> <span id="cb6-22"><a href="#cb6-22"></a> gtk_window_set_application <span class="op">(</span>GTK_WINDOW <span class="op">(</span>alert<span class="op">),</span> GTK_APPLICATION <span class="op">(</span>application<span class="op">));</span></span> <span id="cb6-23"><a href="#cb6-23"></a> gtk_window_present <span class="op">(</span>GTK_WINDOW <span class="op">(</span>alert<span class="op">));</span></span> <span id="cb6-24"><a href="#cb6-24"></a><span class="op">}</span></span> <span id="cb6-25"><a href="#cb6-25"></a></span> <span id="cb6-26"><a href="#cb6-26"></a><span class="dt">static</span> <span class="dt">void</span></span> <span id="cb6-27"><a href="#cb6-27"></a>app_startup <span class="op">(</span>GApplication <span class="op">*</span>application<span class="op">)</span> <span class="op">{</span></span> <span id="cb6-28"><a href="#cb6-28"></a><span class="op">}</span></span> <span id="cb6-29"><a href="#cb6-29"></a></span> <span id="cb6-30"><a href="#cb6-30"></a><span class="pp">#define APPLICATION_ID </span><span class="st">"com.github.ToshioCP.example_tfe_alert"</span></span> <span id="cb6-31"><a href="#cb6-31"></a></span> <span id="cb6-32"><a href="#cb6-32"></a><span class="dt">int</span></span> <span id="cb6-33"><a href="#cb6-33"></a>main <span class="op">(</span><span class="dt">int</span> argc<span class="op">,</span> <span class="dt">char</span> <span class="op">**</span>argv<span class="op">)</span> <span class="op">{</span></span> <span id="cb6-34"><a href="#cb6-34"></a> GtkApplication <span class="op">*</span>app<span class="op">;</span></span> <span id="cb6-35"><a href="#cb6-35"></a> <span class="dt">int</span> stat<span class="op">;</span></span> <span id="cb6-36"><a href="#cb6-36"></a></span> <span id="cb6-37"><a href="#cb6-37"></a> app <span class="op">=</span> gtk_application_new <span class="op">(</span>APPLICATION_ID<span class="op">,</span> G_APPLICATION_DEFAULT_FLAGS<span class="op">);</span></span> <span id="cb6-38"><a href="#cb6-38"></a> g_signal_connect <span class="op">(</span>app<span class="op">,</span> <span class="st">"startup"</span><span class="op">,</span> G_CALLBACK <span class="op">(</span>app_startup<span class="op">),</span> NULL<span class="op">);</span></span> <span id="cb6-39"><a href="#cb6-39"></a> g_signal_connect <span class="op">(</span>app<span class="op">,</span> <span class="st">"activate"</span><span class="op">,</span> G_CALLBACK <span class="op">(</span>app_activate<span class="op">),</span> NULL<span class="op">);</span></span> <span id="cb6-40"><a href="#cb6-40"></a> stat <span class="op">=</span> g_application_run <span class="op">(</span>G_APPLICATION <span class="op">(</span>app<span class="op">),</span> argc<span class="op">,</span> argv<span class="op">);</span></span> <span id="cb6-41"><a href="#cb6-41"></a> g_object_unref <span class="op">(</span>app<span class="op">);</span></span> <span id="cb6-42"><a href="#cb6-42"></a> <span class="cf">return</span> stat<span class="op">;</span></span> <span id="cb6-43"><a href="#cb6-43"></a><span class="op">}</span></span></code></pre></div> <p>The “activate” signal handler <code>app_activate</code> initializes the alert dialog.</p> <ul> <li>A TfeAlert instance is created.</li> <li>Its “response” signal is connected to the handler <code>alert_response_cb</code>.</li> <li>TfeAlert class is a sub class of GtkWindow so it can be a top level window that is connected to an application instance. The function <code>gtk_window_set_application</code> does that.</li> <li>The dialog is shown.</li> </ul> <p>A user clicks on either the cancel button or the accept button. Then, the “response” signal is emitted and the dialog is destroyed. The signal handler <code>alert_response_cb</code> checks the response and prints “Accept” or “Cancel”. If an error happens, it prints “Unexpected error”.</p> <p>You can compile it with meson and ninja.</p> <pre><code>$ cd src/tfe6/example $ meson setup _build $ ninja -C _build $ _build/ex_alert Accept #<= if you clicked on the accept button</code></pre> </div> </div> </div> <script src="https://cdn.jsdelivr.net/npm/bootstrap@5.0.2/dist/js/bootstrap.bundle.min.js" integrity="sha384-MrcW6ZMFYlzcLA8Nl+NtUVF0sA7MsXsP1UyJoMp4YLEuNSfAP+JcXn/tWtIaxVXM" crossorigin="anonymous"></script> </body> </html>