• 增加搜索条

    增加搜索条

    我们继续充实我们应用程序的功能。如今，我们添加搜索。GTK+在GtkSearchEntry和Gtksearchbar中支持这个功能。搜索条是一个可以嵌入顶端来展现搜索输入。

    我们在头栏增加一个开关按钮，他可以用来滑出头栏下的搜索条。

    1. <?xml version="1.0" encoding="UTF-8"?>
    2. <interface>
    3.   <!-- interface-requires gtk+ 3.8 -->
    4.   <template class="ExampleAppWindow" parent="GtkApplicationWindow">
    5.     <property name="title" translatable="yes">Example Application</property>
    6.     <property name="default-width">600</property>
    7.     <property name="default-height">400</property>
    8.     <child>
    9.       <object class="GtkBox" id="content_box">
    10.         <property name="visible">True</property>
    11.         <property name="orientation">vertical</property>
    12.         <child>
    13.           <object class="GtkHeaderBar" id="header">
    14.             <property name="visible">True</property>
    15.             <child type="title">
    16.               <object class="GtkStackSwitcher" id="tabs">
    17.                 <property name="visible">True</property>
    18.                 <property name="margin">6</property>
    19.                 <property name="stack">stack</property>
    20.               </object>
    21.             </child>
    22.             <child>
    23.               <object class="GtkToggleButton" id="search">
    24.                 <property name="visible">True</property>
    25.                 <property name="sensitive">False</property>
    26.                 <style>
    27.                   <class name="image-button"/>
    28.                 </style>
    29.                 <child>
    30.                   <object class="GtkImage" id="search-icon">
    31.                     <property name="visible">True</property>
    32.                     <property name="icon-name">edit-find-symbolic</property>
    33.                     <property name="icon-size">1</property>
    34.                   </object>
    35.                 </child>
    36.               </object>
    37.               <packing>
    38.                 <property name="pack-type">end</property>
    39.               </packing>
    40.             </child>
    41.           </object>
    42.         </child>
    43.         <child>
    44.           <object class="GtkSearchBar" id="searchbar">
    45.             <property name="visible">True</property>
    46.             <child>
    47.               <object class="GtkSearchEntry" id="searchentry">
    48.                 <signal name="search-changed" handler="search_text_changed"/>
    49.                 <property name="visible">True</property>
    50.               </object>
    51.             </child>
    52.           </object>
    53.         </child>
    54.         <child>
    55.           <object class="GtkStack" id="stack">
    56.             <signal name="notify::visible-child" handler="visible_child_changed"/>
    57.             <property name="visible">True</property>
    58.           </object>
    59.         </child>
    60.       </object>
    61.     </child>
    62.   </template>
    63. </interface>

    实现搜索条需要更改一点我们还没打算完成的代码。搜索实现的核心是一个监听搜索条文字变化的信号句柄。

    1. ...
    3. static void
    4. search_text_changed (GtkEntry         *entry,
    5.                      ExampleAppWindow *win)
    6. {
    7.   ExampleAppWindowPrivate *priv;
    8.   const gchar *text;
    9.   GtkWidget *tab;
    10.   GtkWidget *view;
    11.   GtkTextBuffer *buffer;
    12.   GtkTextIter start, match_start, match_end;
    14.   text = gtk_entry_get_text (entry);
    16.   if (text[0] == '\0')
    17.     return;
    19.   priv = example_app_window_get_instance_private (win);
    21.   tab = gtk_stack_get_visible_child (GTK_STACK (priv->stack));
    22.   view = gtk_bin_get_child (GTK_BIN (tab));
    23.   buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (view));
    25.   /* Very simple-minded search implementation */
    26.   gtk_text_buffer_get_start_iter (buffer, &start);
    27.   if (gtk_text_iter_forward_search (&start, text, GTK_TEXT_SEARCH_CASE_INSENSITIVE,
    28.                                     &match_start, &match_end, NULL))
    29.     {
    30.       gtk_text_buffer_select_range (buffer, &match_start, &match_end);
    31.       gtk_text_view_scroll_to_iter (GTK_TEXT_VIEW (view), &match_start,
    32.                                     0.0, FALSE, 0.0, 0.0);
    33.     }
    34. }
    36. static void
    37. example_app_window_init (ExampleAppWindow *win)
    38. {
    40. ...
    42.   gtk_widget_class_bind_template_callback (GTK_WIDGET_CLASS (class), search_text_changed);
    44. ...
    46. }
    48. ...

    (full source)

    加上了搜索条，我们的应用程序现在是这样的：

    getting-started-app7.png