== Introduction ==

Make a popup menu when you right-click something.

== What Objects are Involved ==

|| Source Component || Component that was clicked. ||
|| {1} Menu Launcher || Event handler, launches the menu. ||
|| {2} Menu || Popup menu itself. ||
|| {3} Menu Handlers || Menu responses to selection. ||

== Process Overview ==

 1. Register source's {{{EVT_}}}s to invoke {1} launcher.
 2.  {1} Launcher creates {2} {{{wxMenu}}}.
 3.  {1} Launcher packs {2} menu with {{{Append}}}.
 4.  {1} Launcher registers {3} menu handlers with {{{EVT_MENU}}}, on the {2} menu.
 5.  {1} Launcher displays {2} menu with call to {{{PopupMenu}}}, invoked on the source component, passing event's {{{GetPoint}}}.

The {{{GetPoint}}} tells {{{PopupMenu}}} ''where'' to place the {{{PopupMenu}}}. (That is: Where the user right-clicked, the popup menu should appear.)

== Special Concerns ==

In general:
  I don't know why {{{PopupMenu}}} isn't a global function.
  You ''must'' call it in the context of a wxWindow.

The code below:
  There may be a way to communicate the list item clicked on to the menu handler via the event object, rather than the App object. 

== Code Sample ==

{{{
#!python
from wxPython.wx import *



menu_titles = [ "Open",
                "Properties",
                "Rename",
                "Delete" ]

menu_title_by_id = {}
for title in menu_titles:
    menu_title_by_id[ wxNewId() ] = title



list_title = "files"
list_items = [ "binding.py",
               "clipboard.py",
               "config.py",
               "debug.py",
               "dialog.py",
               "dispatch.py",
               "error.py", ]



class App( wxPySimpleApp ):
    def OnInit( self ):
        # build frame
        frame = wxFrame(NULL, -1, "Hello from wxPython")
        self.frame = frame # we'll use in RightClickCb

        # build list
        list  = wxListCtrl( frame, -1, style=wxLC_REPORT )
        list.InsertColumn( 0, list_title )
        for x in list_items: list.InsertStringItem(0,x)

        ### 1. Register source's EVT_s to invoke launcher. ###
        EVT_LIST_ITEM_RIGHT_CLICK( list, -1, self.RightClickCb )

        # clear variables
        self.list_item_clicked = None

        # show & run
        frame.Show(1)
        return 1

    def RightClickCb( self, event ):
        # record what was clicked
        self.list_item_clicked = right_click_context = event.GetText()
        
        ### 2. Launcher creates wxMenu. ###
        menu = wxMenu()
        for (id,title) in menu_title_by_id.items():
            ### 3. Launcher packs menu with Append. ###
            menu.Append( id, title )
            ### 4. Launcher registers menu handlers with EVT_MENU, on the menu. ###
            EVT_MENU( menu, id, self.MenuSelectionCb )

        ### 5. Launcher displays menu with call to PopupMenu, invoked on the source component, passing event's GetPoint. ###
        self.frame.PopupMenu( menu, event.GetPoint() )
        menu.Destroy() # destroy to avoid mem leak
        
    def MenuSelectionCb( self, event ):
        # do something
        operation = menu_title_by_id[ event.GetId() ]
        target    = self.list_item_clicked
        print 'Perform "%(operation)s" on "%(target)s."' % vars()

app = App()
app.MainLoop()
}}}

=== Comments ===

Commit code improvements above, comment freely below. -- LionKimbro <<DateTime(2003-08-21T14:40:27)>>

Experiment with the icons {1} {2} {3}. Ideally, I'd get around to installing working Java on Mozilla, and then I could just diagram this process exactly like I want to... -- LionKimbro <<DateTime(2003-10-17T11:59:29)>>

The above code has some problem in wx 2.5.3.1, in right click callback a call to {{{event.GetText()}}} returns empty string. Same for 2.6.0.0, so I think it's some "backward incompatibility" with wx... ;). -- Jarek Zgoda

wx.Menu objects need to be explicitly destroyed (e.g. menu.Destroy()) in this situation.  Otherwise, they will rack up the USER Objects count on Windows; eventually crashing a program when USER Objects is maxed out. -- U. Artie Eoff <<DateTime(2008-10-06T12:02:00)>>