gtk_tut-12.html

gtk 开发手册和参考文档。 包括gtk glib gdk等

    gtk_widget_show(scrolled_window);
    
    /* create the GtkList widget
     * connect the sigh_print_selection() signal handler
     * function to the "selection_changed" signal of the GtkList
     * to print out the selected items each time the selection
     * has changed */
    gtklist=gtk_list_new();
    gtk_container_add(GTK_CONTAINER(scrolled_window), gtklist);
    gtk_widget_show(gtklist);
    gtk_signal_connect(GTK_OBJECT(gtklist),
                       "selection_changed",
                       GTK_SIGNAL_FUNC(sigh_print_selection),
                       NULL);
    
    /* we create a "Prison" to put a list item in ;)
     */
    frame=gtk_frame_new("Prison");
    gtk_widget_set_usize(frame, 200, 50);
    gtk_container_border_width(GTK_CONTAINER(frame), 5);
    gtk_frame_set_shadow_type(GTK_FRAME(frame), GTK_SHADOW_OUT);
    gtk_container_add(GTK_CONTAINER(vbox), frame);
    gtk_widget_show(frame);
    
    /* connect the sigh_button_event() signal handler to the GtkList
     * wich will handle the "arresting" of list items
     */
    gtk_signal_connect(GTK_OBJECT(gtklist),
                       "button_release_event",
                       GTK_SIGNAL_FUNC(sigh_button_event),
                       frame);
    
    /* create a separator
     */
    separator=gtk_hseparator_new();
    gtk_container_add(GTK_CONTAINER(vbox), separator);
    gtk_widget_show(separator);
    
    /* finaly create a button and connect it愀 "clicked" signal
     * to the destroyment of the window
     */
    button=gtk_button_new_with_label("Close");
    gtk_container_add(GTK_CONTAINER(vbox), button);
    gtk_widget_show(button);
    gtk_signal_connect_object(GTK_OBJECT(button),
                              "clicked",
                              GTK_SIGNAL_FUNC(gtk_widget_destroy),
                              GTK_OBJECT(window));
    
    
    /* now we create 5 list items, each having it愀 own
     * label and add them to the GtkList using gtk_container_add()
     * also we query the text string from the label and
     * associate it with the list_item_data_key for each list item
     */
    for (i=0; i<5; i++) {
        GtkWidget       *label;
        gchar           *string;
        
        sprintf(buffer, "ListItemContainer with Label #%d", i);
        label=gtk_label_new(buffer);
        list_item=gtk_list_item_new();
        gtk_container_add(GTK_CONTAINER(list_item), label);
        gtk_widget_show(label);
        gtk_container_add(GTK_CONTAINER(gtklist), list_item);
        gtk_widget_show(list_item);
        gtk_label_get(GTK_LABEL(label), &string);
        gtk_object_set_data(GTK_OBJECT(list_item),
                            list_item_data_key,
                            string);
    }
    /* here, we are creating another 5 labels, this time
     * we use gtk_list_item_new_with_label() for the creation
     * we can憩 query the text string from the label because
     * we don憩 have the labels pointer and therefore
     * we just associate the list_item_data_key of each
     * list item with the same text string
     * for adding of the list items we put them all into a doubly
     * linked list (GList), and then add them by a single call to
     * gtk_list_append_items()
     * because we use g_list_prepend() to put the items into the
     * doubly linked list, their order will be descending (instead
     * of ascending when using g_list_append())
     */
    dlist=NULL;
    for (; i<10; i++) {
        sprintf(buffer, "List Item with Label %d", i);
        list_item=gtk_list_item_new_with_label(buffer);
        dlist=g_list_prepend(dlist, list_item);
        gtk_widget_show(list_item);
        gtk_object_set_data(GTK_OBJECT(list_item),
                            list_item_data_key,
                            "ListItem with integrated Label");
    }
    gtk_list_append_items(GTK_LIST(gtklist), dlist);
    
    /* finaly we want to see the window, don憩 we? ;)
     */
    gtk_widget_show(window);
    
    /* fire up the main event loop of gtk
     */
    gtk_main();
    
    /* we get here after gtk_main_quit() has been called which
     * happens if the main window gets destroyed
     */
    return 0;
}

/* this is the signal handler that got connected to button
 * press/release events of the GtkList
 */
void
sigh_button_event       (GtkWidget      *gtklist,
                         GdkEventButton *event,
                         GtkWidget      *frame)
{
    /* we only do something if the third (rightmost mouse button
     * was released
     */
    if (event->type==GDK_BUTTON_RELEASE &&
        event->button==3) {
        GList           *dlist, *free_list;
        GtkWidget       *new_prisoner;
        
        /* fetch the currently selected list item which
         * will be our next prisoner ;)
         */
        dlist=GTK_LIST(gtklist)->selection;
        if (dlist)
                new_prisoner=GTK_WIDGET(dlist->data);
        else
                new_prisoner=NULL;
        
        /* look for already prisoned list items, we
         * will put them back into the list
         * remember to free the doubly linked list that
         * gtk_container_children() returns
         */
        dlist=gtk_container_children(GTK_CONTAINER(frame));
        free_list=dlist;
        while (dlist) {
            GtkWidget       *list_item;
            
            list_item=dlist->data;
            
            gtk_widget_reparent(list_item, gtklist);
            
            dlist=dlist->next;
        }
        g_list_free(free_list);
        
        /* if we have a new prisoner, remove him from the
         * GtkList and put him into the frame "Prison"
         * we need to unselect the item before
         */
        if (new_prisoner) {
            GList   static_dlist;
            
            static_dlist.data=new_prisoner;
            static_dlist.next=NULL;
            static_dlist.prev=NULL;
            
            gtk_list_unselect_child(GTK_LIST(gtklist),
                                    new_prisoner);
            gtk_widget_reparent(new_prisoner, frame);
        }
    }
}

/* this is the signal handler that gets called if GtkList
 * emits the "selection_changed" signal
 */
void
sigh_print_selection    (GtkWidget      *gtklist,
                         gpointer       func_data)
{
    GList   *dlist;
    
    /* fetch the doubly linked list of selected items
     * of the GtkList, remember to treat this as read-only!
     */
    dlist=GTK_LIST(gtklist)->selection;
    
    /* if there are no selected items there is nothing more
     * to do than just telling the user so
     */
    if (!dlist) {
        g_print("Selection cleared\n");
        return;
    }
    /* ok, we got a selection and so we print it
     */
    g_print("The selection is a ");
    
    /* get the list item from the doubly linked list
     * and then query the data associated with list_item_data_key
     * we then just print it
     */
    while (dlist) {
        GtkObject       *list_item;
        gchar           *item_data_string;
        
        list_item=GTK_OBJECT(dlist->data);
        item_data_string=gtk_object_get_data(list_item,
                                             list_item_data_key);
        g_print("%s ", item_data_string);
        
        dlist=dlist->next;
    }
    g_print("\n");
}
</PRE>
</CODE></BLOCKQUOTE>
<P>
<H2><A NAME="ss12.4">12.4 List Item物件</A>
</H2>

<P>GtkListItem物件是设计用来做为container的子物件,
用来提供selection/deselection的功能.

<P>
GtkListItem有自己的视窗来接收事件并有其自身的背景颜色, 一般是白色的.

<P>
因为是由GtkItem而来的, 它也可以用GTK_ITEM(ListItem)巨集.
一般GtkListItem只有一个标签, 用来记录例如一个档名.
另外还有一个很好用的函数gtk_list_item_new_with_label().
若您不想加GtkLabel到GtkListItem,
也可以加GtkVBox或GtkArrow.
<P>
<H2><A NAME="ss12.5">12.5 信号</A>
</H2>

<P>
GtkListItem不产生自己的新的信号,
但它继承GtkItem的信号.

<P>
<P>
<H2><A NAME="ss12.6">12.6 函数</A>
</H2>

<P>
<P>
<BLOCKQUOTE><CODE>
<PRE>
guint gtk_list_item_get_type (void)
</PRE>
</CODE></BLOCKQUOTE>
<P>返回`GtkListItem' type identifier.
<P>
<BLOCKQUOTE><CODE>
<PRE>
GtkWidget* gtk_list_item_new (void)
</PRE>
</CODE></BLOCKQUOTE>
<P>
产生新的`GtkListItem' object.
新物件返回一个指标给`GtkWidget'物件. `NULL'表示错误.
<P>
<BLOCKQUOTE><CODE>
<PRE>
GtkWidget* gtk_list_item_new_with_label (gchar *LABEL)
</PRE>
</CODE></BLOCKQUOTE>
<P>
产生新的`GtkListItem'物件, 并带一个标签.

并返回一个`GtkWidget' object.
`NULL'表示错误.
<P>
<BLOCKQUOTE><CODE>
<PRE>
void gtk_list_item_select (GtkListItem *LIST_ITEM)
</PRE>
</CODE></BLOCKQUOTE>
<P>
这个函数基本上是将gtk_item_select (GTK_ITEM (list_item))包装起来.
它将会送GtkItem::select信号.
*Note GtkItem::, for more info.
<P>
<BLOCKQUOTE><CODE>
<PRE>
void gtk_list_item_deselect (GtkListItem *LIST_ITEM)
</PRE>
</CODE></BLOCKQUOTE>
<P>
这个函数基本上是将gtk_item_deselect (GTK_ITEM (list_item))包装起来.
它将会送GtkItem::deselect信号.
*Note GtkItem::, for more info.
<P>
<BLOCKQUOTE><CODE>
<PRE>
GtkListItem* GTK_LIST_ITEM (gpointer OBJ)
</PRE>
</CODE></BLOCKQUOTE>
<P>传一个generic pointer到`GtkListItem*'. 
*Note Standard Macros::, for more info.
<P>
<BLOCKQUOTE><CODE>
<PRE>
GtkListItemClass* GTK_LIST_ITEM_CLASS (gpointer CLASS)
</PRE>
</CODE></BLOCKQUOTE>
<P>传一个generic pointer到`GtkListItemClass*'. 
*Note Standard Macros::, for more info.
<P>
<BLOCKQUOTE><CODE>
<PRE>
gint GTK_IS_LIST_ITEM (gpointer OBJ)
</PRE>
</CODE></BLOCKQUOTE>
<P>
决定generic pointer是否对照到`GtkListItem' object.
*Note Standard Macros::, for more info.
<P>
<H2><A NAME="ss12.7">12.7 例子</A>
</H2>

<P>
Please see the GtkList example on this, which covers the usage of a
GtkListItem as well.
<P>
<hr>
译注: List物件这一篇本身比较不容易翻译, 因原文本身讲的并不太清楚.
此外, 其结构原本就比较繁琐.
若您在此糟遇问题, 可来信反应. 译者会想办法将其改善.
<br>
If you got stuck here, it's mostly not your problem.
Don't feel frustration.
The List Widget itself is pretty complicated.
You may drop me a word if you need. I will try to improve it.
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