== Introduction ==

Accelerator keys are often a more efficient way of interacting with a GUI that are mouse gestures. However, wxPython does not appear to offer a direct way of associating the label of a textbox, or of another control, with the control itself.

This recipe shows how to associate the accelerator keys implied by a collection of static labels with the appropriate controls in such a way that, when an accelerator key is pressed the associated control gains focus.

== What Objects are Involved ==

  * `wxStaticText`, for the control labels
  * `wxTextCtrl`, `wxComboBox` and `wxCheckBox`, as examples of controls that may be labelled with `wxStaticText`
  * `wxAcceleratorTable`, which is wxPython's container for information about accelerators and their associated controls.

== Process Overview ==

In the following example:

  * the series of controls, including a combo box, some edit boxes and so on, are created first
  * a class, called `AccumAcceleratorTable`, is instantiated that will
    * identify accelerator keys from label texts
    * accumulate information about the associations among accelerators, static labels and controls for later use
    * create appropriate event mappings
  * the series of static labels corresponding to the controls are created, and information about the associations accumulated using the aforementioned class instance
  * the accumulated information is made available for the duration of the script's execution.

Note that the method called focusHandler uses information that is accumulated in a dictionary to decide which control is to receive focus based on incoming menu event information.

== Special Concerns ==

My main concern is that I might have failed to notice machinery that is already available in wxPython for doing this.

== Code Sample ==

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

from re import compile,IGNORECASE

class mainWindow(wxFrame):
    def __init__(self,parent,id,title):
        wxFrame.__init__(self,parent,-1,title,size=(500,200),
                        style=wxDEFAULT_FRAME_STYLE | wxNO_FULL_REPAINT_ON_RESIZE)

        self.mainPanel=wxPanel(self,-1)

        # create controls to be subsequently associated with accelerator keys
        self.dateEdit=wxTextCtrl(self.mainPanel,wxNewId(),'',(100,20))
        self.comboBox=wxComboBox(self.mainPanel,wxNewId() ,'',(100,40),(-1,-1),[],wxCB_DROPDOWN)
        self.activityEdit=wxTextCtrl(self.mainPanel,wxNewId(),'',(100,60))
        self.hoursEdit=wxTextCtrl(self.mainPanel,wxNewId(),'',(100,80))
        self.visitedBox=wxCheckBox(self.mainPanel,wxNewId(),'',(100,100))

        # instance a class that accummulates information about controls and accelerators
        accumAcceleratorTable=self.AccumAcceleratorTable(self,self.focusHandler)

        # as each label is created associate appropriate accelerator key with a control
        dateEditLabel=wxStaticText(self.mainPanel,-1,accumAcceleratorTable ('&Date',self.dateEdit),(10,20))
        clientEditLabel=wxStaticText(self.mainPanel,-1,accumAcceleratorTable ('&Client',self.comboBox),(10,40))
        activityEditLabel=wxStaticText(self.mainPanel,-1,accumAcceleratorTable ('&Activity',self.activityEdit),(10,60))
        hoursEditLabel=wxStaticText(self.mainPanel,-1,accumAcceleratorTable ('&Hours',self.hoursEdit),(10,80))
        visitedEditLabel=wxStaticText(self.mainPanel,-1,accumAcceleratorTable ('&Visited',self.visitedBox),(10,100))

        # put the accummulated accelerator table and associations to use
        self.SetAcceleratorTable(wxAcceleratorTable(accumAcceleratorTable.acceleratorTable))
        self.idControlDict=accumAcceleratorTable.idControlDict

        self.Show(True)

    def focusHandler(self,event):
        self.idControlDict[event.GetId()].SetFocus()

    class AccumAcceleratorTable:
        def __init__(self,parent,focusHandler):
            self.acceleratorTable=[]
            self.idControlDict={ }
            self.patt=compile(r'&([a-z])',IGNORECASE)
            self.focusHandler=focusHandler
            self.parent=parent

        def __call__(self,labelText,controlToFocus):
            # find the accelerator key,if any,in the label
            result=self.patt.search(labelText)
            if result:
                anId=wxNewId()
                self.acceleratorTable.append(( wxACCEL_ALT,ord(result.group(1).upper()),anId))
                self.idControlDict[anId]=controlToFocus
                EVT_MENU(self.parent,anId,self.focusHandler)
            return labelText

class App(wxApp):
    def OnInit(self):
        frame=mainWindow(None,-1,"Associating labels with controls")
        self.SetTopWindow(frame)
        return True

if __name__=="__main__":
    app=App(0)
    app.MainLoop()


}}}

=== Comments ===

If you have comments or suggestions, please contact [[Bill Bell]].