为gtktreeview视图区域增加拖拽效果

    在触摸设备上做软件开发很多时候需要界面实现拖拽效果，近期的电话软件开发中设计到了列表控件（gtktreeview实现），比如通讯录，铃音列表等，控件完成后也为其增加了拖拽效果，仅仅实现了y轴的拖拽效果，总结如下:


创建全局标识：

//是否处于拖拽状态
gboolean DRAG = FALSE;

gint drag_last_y;

创建好列表控件后为其连接信号：
g_signal_connect(G_OBJECT（pTreeView), "motion_notify_event",
             G_CALLBACK(mouse_motion_cb), NULL);
g_signal_connect(G_OBJECT(pTreeView), "button_press_event",
             G_CALLBACK(mouse_press_cb), NULL);
g_signal_connect(G_OBJECT(pTreeView), "button_release_event",
             G_CALLBACK(mouse_release_cb), NULL);

实现对应的回调函数：


static gint mouse_motion_cb(GtkWidget *widget, GdkEventButton *bevent, gpointer data)
{  
    if(DRAG)
    {  
        gint tx, ty;

        //获取当前binwindow（0，0）位置 对应的tree coordinates中的坐标

        gtk_tree_view_convert_bin_window_to_tree_coords(widget
                                                         0,
                                                         0,
                                                         &tx,
                                                         &ty);
        //拖拽过程中在y轴的位移
        gint moved = bevent->y - drag_last_y;

        drag_last_y = bevent->y;
       
        gtk_tree_view_scroll_to_point(pList->pTreeView, -1, ty -  moved);
       
    }

    return FALSE;
}



static gint mouse_press_cb(GtkWidget *widget, GdkEventButton *bevent, gpointer data)
{
    DRAG = TRUE;
    drag_last_y = bevent->y;
   
    return FALSE;
}

static gint mouse_release_cb(GtkWidget *widget, GdkEventButton *bevent, gpointer data)
{
    DRAG = FALSE;
   
    return FALSE;
}