A menu is a popup (or pull down) list of items, one of which may be selected before the menu goes away (clicking elsewhere dismisses the menu). Menus may be used to construct either menu bars or popup menus.
A menu item has an integer ID associated with it which can be used to identify the selection, or to change the menu item in some way. A menu item with a special identifier -1 is a separator item and doesn't have an associated command but just makes a separator line appear in the menu.
NB: Please note that wxID_ABOUT and wxID_EXIT are predefined by wxWidgets and have a special meaning since entries using these IDs will be taken out of the normal menus under MacOS X and will be inserted into the system menu (following the appropriate MacOS X interface guideline). On PalmOS wxID_EXIT is disabled according to Palm OS Companion guidelines.
Menu items may be either normal items, check items or radio items. Normal items don't have any special properties while the check items have a boolean flag associated to them and they show a checkmark in the menu when the flag is set. wxWidgets automatically toggles the flag value when the item is clicked and its value may be retrieved using either IsChecked method of wxMenu or wxMenuBar itself or by using wxEvent::IsChecked when you get the menu notification for the item in question.
The radio items are similar to the check items except that all the other items in the same radio group are unchecked when a radio item is checked. The radio group is formed by a contiguous range of radio items, i.e. it starts at the first item of this kind and ends with the first item of a different kind (or the end of the menu). Notice that because the radio groups are defined in terms of the item positions inserting or removing the items in the menu containing the radio items risks to not work correctly. Finally note that radio items are not supported under Motif.
Allocation strategy
All menus except the popup ones must be created on the heap. All menus attached to a menubar or to another menu will be deleted by their parent when it is deleted. As the frame menubar is deleted by the frame itself, it means that normally all menus used are deleted automatically.
Derived from
Include files
<wx/menu.h>
Event handling
If the menu is part of a menubar, then wxMenuBar event processing is used.
With a popup menu, there is a variety of ways to handle a menu selection event (wxEVT_COMMAND_MENU_SELECTED).
See also
wxMenuBar, wxWindow::PopupMenu, Event handling overview, wxFileHistory (most recently used files menu)
Members
wxMenu::wxMenu
wxMenu::~wxMenu
wxMenu::Append
wxMenu::AppendCheckItem
wxMenu::AppendRadioItem
wxMenu::AppendSeparator
wxMenu::AppendSubMenu
wxMenu::Break
wxMenu::Check
wxMenu::Delete
wxMenu::Destroy
wxMenu::Enable
wxMenu::FindItem
wxMenu::FindItemByPosition
wxMenu::GetHelpString
wxMenu::GetLabel
wxMenu::GetMenuItemCount
wxMenu::GetMenuItems
wxMenu::GetTitle
wxMenu::Insert
wxMenu::InsertCheckItem
wxMenu::InsertRadioItem
wxMenu::InsertSeparator
wxMenu::IsChecked
wxMenu::IsEnabled
wxMenu::Prepend
wxMenu::PrependCheckItem
wxMenu::PrependRadioItem
wxMenu::PrependSeparator
wxMenu::Remove
wxMenu::SetHelpString
wxMenu::SetLabel
wxMenu::SetTitle
wxMenu::UpdateUI
wxMenu(const wxString& title = "", long style = 0)
Constructs a wxMenu object.
Parameters
title
style
wxMenu(long style)
Constructs a wxMenu object.
Parameters
style
~wxMenu()
Destructor, destroying the menu.
Note: under Motif, a popup menu must have a valid parent (the window it was last popped up on) when being destroyed. Therefore, make sure you delete or re-use the popup menu before destroying the parent window. Re-use in this context means popping up the menu on a different window from last time, which causes an implicit destruction and recreation of internal data structures.
wxMenuItem* Append(int id, const wxString& item = "", const wxString& helpString = "", wxItemKind kind = wxITEM_NORMAL)
Adds a string item to the end of the menu.
wxMenuItem* Append(int id, const wxString& item, wxMenu *subMenu, const wxString& helpString = "")
Adds a pull-right submenu to the end of the menu. Append the submenu to the parent menu after you have added your menu items, or accelerators may not be registered properly.
wxMenuItem* Append(wxMenuItem* menuItem)
Adds a menu item object. This is the most generic variant of Append() method because it may be used for both items (including separators) and submenus and because you can also specify various extra properties of a menu item this way, such as bitmaps and fonts.
Parameters
id
item
menu
kind
helpString
menuItem
Remarks
This command can be used after the menu has been shown, as well as on initial creation of a menu or menubar.
The item string for the normal menu items (not submenus or separators) may include the accelerator which can be used to activate the menu item from keyboard. The accelerator string follows the item label and is separated from it by a TAB character ('\t'). Its general syntax is any combination of "CTRL", "ALT" and "SHIFT" strings (case doesn't matter) separated by either '-' or '+' characters and followed by the accelerator itself. The accelerator may be any alphanumeric character, any function key (from F1 to F12) or one of the special characters listed in the table below (again, case doesn't matter):
| DEL or DELETE | Delete key |
| INS or INSERT | Insert key |
| ENTER or RETURN | Enter key |
| PGUP | PageUp key |
| PGDN | PageDown key |
| LEFT | Left cursor arrow key |
| RIGHT | Right cursor arrow key |
| UP | Up cursor arrow key |
| DOWN | Down cursor arrow key |
| HOME | Home key |
| END | End key |
| SPACE | Space |
| TAB | Tab key |
| ESC or ESCAPE | Escape key (Windows only) |
See also
wxMenu::AppendSeparator, wxMenu::AppendCheckItem, wxMenu::AppendRadioItem, wxMenu::AppendSubMenu, wxMenu::Insert, wxMenu::SetLabel, wxMenu::GetHelpString, wxMenu::SetHelpString, wxMenuItem
wxPython note: In place of a single overloaded method name, wxPython implements the following methods:
| Append(id, string, helpStr="", checkable=false) | |
| AppendMenu(id, string, aMenu, helpStr="") | |
| AppendItem(aMenuItem) |
wxMenuItem* AppendCheckItem(int id, const wxString& item, const wxString& helpString = "")
Adds a checkable item to the end of the menu.
See also
wxMenu::Append, wxMenu::InsertCheckItem
wxMenuItem* AppendRadioItem(int id, const wxString& item, const wxString& helpString = "")
Adds a radio item to the end of the menu. All consequent radio items form a group and when an item in the group is checked, all the others are automatically unchecked.
See also
wxMenu::Append, wxMenu::InsertRadioItem
wxMenuItem* AppendSeparator()
Adds a separator to the end of the menu.
See also
wxMenu::Append, wxMenu::InsertSeparator
wxMenuItem * AppendSubMenu(wxMenu *submenu, const wxString& text, const wxString& help = wxEmptyString)
Adds the given submenu to this menu. text is the text shown in the menu for it and help is the help string shown in the status bar when the submenu item is selected.
void Break()
Inserts a break in a menu, causing the next appended item to appear in a new column.
void Check(int id, const bool check)
Checks or unchecks the menu item.
Parameters
id
check
See also
void Delete(int id)
void Delete(wxMenuItem *item)
Deletes the menu item from the menu. If the item is a submenu, it will not be deleted. Use Destroy if you want to delete a submenu.
Parameters
id
item
See also
wxMenu::FindItem, wxMenu::Destroy, wxMenu::Remove
void Destroy(int id)
void Destroy(wxMenuItem *item)
Deletes the menu item from the menu. If the item is a submenu, it will be deleted. Use Remove if you want to keep the submenu (for example, to reuse it later).
Parameters
id
item
See also
wxMenu::FindItem, wxMenu::Deletes, wxMenu::Remove
void Enable(int id, const bool enable)
Enables or disables (greys out) a menu item.
Parameters
id
enable
See also
int FindItem(const wxString& itemString) const
Finds the menu item id for a menu item string.
wxMenuItem * FindItem(int id, wxMenu **menu = NULL) const
Finds the menu item object associated with the given menu item identifier and, optionally, the (sub)menu it belongs to.
Parameters
itemString
id
menu
Return value
First form: menu item identifier, or wxNOT_FOUND if none is found.
Second form: returns the menu item object, or NULL if it is not found.
Remarks
Any special menu codes are stripped out of source and target strings before matching.
wxPython note: The name of this method in wxPython is FindItemById and it does not support the second parameter.
wxMenuItem* FindItemByPosition(size_t position) const
Returns the wxMenuItem given a position in the menu.
wxString GetHelpString(int id) const
Returns the help string associated with a menu item.
Parameters
id
Return value
The help string, or the empty string if there is no help string or the item was not found.
See also
wxMenu::SetHelpString, wxMenu::Append
wxString GetLabel(int id) const
Returns a menu item label.
Parameters
id
Return value
The item label, or the empty string if the item was not found.
See also
size_t GetMenuItemCount() const
Returns the number of items in the menu.
wxMenuItemList& GetMenuItems() const
Returns the list of items in the menu. wxMenuItemList is a pseudo-template list class containing wxMenuItem pointers, see wxList.
wxString GetTitle() const
Returns the title of the menu.
Remarks
This is relevant only to popup menus, use wxMenuBar::GetLabelTop for the menus in the menubar.
See also
wxMenuItem* Insert(size_t pos, wxMenuItem *item)
wxMenuItem* Insert(size_t pos, int id, const wxString& item = "", const wxString& helpString = "", wxItemKind kind = wxITEM_NORMAL)
Inserts the given item before the position pos. Inserting the item at position GetMenuItemCount is the same as appending it.
See also
wxMenu::Append, wxMenu::Prepend
wxMenuItem* InsertCheckItem(size_t pos, int id, const wxString& item, const wxString& helpString = "")
Inserts a checkable item at the given position.
See also
wxMenu::Insert, wxMenu::AppendCheckItem
wxMenuItem* InsertRadioItem(size_t pos, int id, const wxString& item, const wxString& helpString = "")
Inserts a radio item at the given position.
See also
wxMenu::Insert, wxMenu::AppendRadioItem
wxMenuItem* InsertSeparator(size_t pos)
Inserts a separator at the given position.
See also
wxMenu::Insert, wxMenu::AppendSeparator
bool IsChecked(int id) const
Determines whether a menu item is checked.
Parameters
id
Return value
true if the menu item is checked, false otherwise.
See also
bool IsEnabled(int id) const
Determines whether a menu item is enabled.
Parameters
id
Return value
true if the menu item is enabled, false otherwise.
See also
wxMenuItem* Prepend(wxMenuItem *item)
wxMenuItem* Prepend(int id, const wxString& item = "", const wxString& helpString = "", wxItemKind kind = wxITEM_NORMAL)
Inserts the given item at position 0, i.e. before all the other existing items.
See also
wxMenu::Append, wxMenu::Insert
wxMenuItem* PrependCheckItem(int id, const wxString& item, const wxString& helpString = "")
Inserts a checkable item at position 0.
See also
wxMenu::Prepend, wxMenu::AppendCheckItem
wxMenuItem* PrependRadioItem(int id, const wxString& item, const wxString& helpString = "")
Inserts a radio item at position 0.
See also
wxMenu::Prepend, wxMenu::AppendRadioItem
wxMenuItem* PrependSeparator()
Inserts a separator at position 0.
See also
wxMenu::Prepend, wxMenu::AppendSeparator
wxMenuItem * Remove(int id)
wxMenuItem * Remove(wxMenuItem *item)
Removes the menu item from the menu but doesn't delete the associated C++ object. This allows to reuse the same item later by adding it back to the menu (especially useful with submenus).
Parameters
id
item
Return value
The item which was detached from the menu.
void SetHelpString(int id, const wxString& helpString)
Sets an item's help string.
Parameters
id
helpString
See also
void SetLabel(int id, const wxString& label)
Sets the label of a menu item.
Parameters
id
label
See also
wxMenu::Append, wxMenu::GetLabel
void SetTitle(const wxString& title)
Sets the title of the menu.
Parameters
title
Remarks
This is relevant only to popup menus, use wxMenuBar::SetLabelTop for the menus in the menubar.
See also
void UpdateUI(wxEvtHandler* source = NULL) const
Sends events to source (or owning window if NULL) to update the menu UI. This is called just before the menu is popped up with wxWindow::PopupMenu, but the application may call it at other times if required.
See also