GtkCheckMenuItem、GtkRadioMenuItem與GtkTearoffMenuItem都是GtkMenuItem的子類,GtkCheckMenuItem可以產生一個核取方塊,GtkRadioMenuItem產生單選鈕,它們的使用上與 GtkCheckButton 與 GtkRadioButton 類似。
由於GtkRadioMenuItem是單選鈕,因此必須設定其群組,第一次產生GtkRadioMenuItem時群組可設定為NULL,第二次則使用 gtk_radio_menu_item_group()取得第一個GtkRadioMenuItem的群組(GSList),然後再用以產生第二個 GtkRadioMenuIte:
cutMenuItem = gtk_radio_menu_item_new_with_label(NULL, "Cut");
copyMenuItem = gtk_radio_menu_item_new_with_label(
gtk_radio_menu_item_group(GTK_RADIO_MENU_ITEM(cutMenuItem)),
"Copy");
copyMenuItem = gtk_radio_menu_item_new_with_label(
gtk_radio_menu_item_group(GTK_RADIO_MENU_ITEM(cutMenuItem)),
"Copy");
GtkTearoffMenuItem是個特殊的選項,外觀為一個虛線,按下後,會使得整個GtkMenu剝離(tear off)而成為浮動選單。
您可以改寫一下 GtkMenuBar、GtkMenu 與 GtkMenuItem 中的範例,新增一個函式:
...
GtkWidget* createEditMenuItem() {
GtkWidget *rootEditItem;
GtkWidget *editMenu;
GtkWidget *cutMenuItem;
GtkWidget *copyMenuItem;
GtkWidget *pasteMenuItem;
rootEditItem = gtk_menu_item_new_with_mnemonic("_Edit");
editMenu = gtk_menu_new();
cutMenuItem = gtk_radio_menu_item_new_with_label(NULL, "Cut");
copyMenuItem = gtk_radio_menu_item_new_with_label(
gtk_radio_menu_item_group(GTK_RADIO_MENU_ITEM(cutMenuItem)),
"Copy");
pasteMenuItem = gtk_check_menu_item_new_with_label("Paste");
gtk_menu_shell_append(GTK_MENU_SHELL(editMenu),
gtk_tearoff_menu_item_new());
gtk_menu_shell_append(GTK_MENU_SHELL(editMenu), cutMenuItem);
gtk_menu_shell_append(GTK_MENU_SHELL(editMenu), copyMenuItem);
gtk_menu_shell_append(GTK_MENU_SHELL(editMenu), pasteMenuItem);
gtk_menu_item_set_submenu(GTK_MENU_ITEM(rootEditItem), editMenu);
return rootEditItem;
}
...
然後改一下main()函式中附加GtkMenuBar選項Edit的部份:GtkWidget* createEditMenuItem() {
GtkWidget *rootEditItem;
GtkWidget *editMenu;
GtkWidget *cutMenuItem;
GtkWidget *copyMenuItem;
GtkWidget *pasteMenuItem;
rootEditItem = gtk_menu_item_new_with_mnemonic("_Edit");
editMenu = gtk_menu_new();
cutMenuItem = gtk_radio_menu_item_new_with_label(NULL, "Cut");
copyMenuItem = gtk_radio_menu_item_new_with_label(
gtk_radio_menu_item_group(GTK_RADIO_MENU_ITEM(cutMenuItem)),
"Copy");
pasteMenuItem = gtk_check_menu_item_new_with_label("Paste");
gtk_menu_shell_append(GTK_MENU_SHELL(editMenu),
gtk_tearoff_menu_item_new());
gtk_menu_shell_append(GTK_MENU_SHELL(editMenu), cutMenuItem);
gtk_menu_shell_append(GTK_MENU_SHELL(editMenu), copyMenuItem);
gtk_menu_shell_append(GTK_MENU_SHELL(editMenu), pasteMenuItem);
gtk_menu_item_set_submenu(GTK_MENU_ITEM(rootEditItem), editMenu);
return rootEditItem;
}
...
gtk_menu_bar_append(menubar, createEditMenuItem());
下圖為改寫後,Edit選單的畫面:
下圖為Edit選單成為浮動的一個畫面: