huey: Internal maintenance specification

For gridding information, see Section 13, “class NamePicker: Select colors by name”.

# - - -   N a m e P i c k e r . _ _ c r e a t e W i d g e t s

    def __createWidgets ( self ):
        """Create all widgets."""

        #-- 1 --
        # [ self  :=  self with a new Label to label the color
        #             name entry field
        #   self.__entryLabel  :=  that Label ]
        self.__entryLabel  =  Label ( self,
            font=BUTTON_FONT, text="Type a color name:" )
        rowx  =  0
        self.__entryLabel.grid ( row=rowx, column=0, sticky=W )

The Entry field has an important event binding: if the user presses the Enter key (which is called Return in Tkinter), that means they have selected a color, so the callback must be called. The binding uses the handler method Section 13.3, “NamePicker.__entryHandler(): Handler for the Enter key”.

        #-- 2 --
        # [ self  :=  self with a new Entry whose control variable
        #       is self.__entryVar, and which calls self.__callback
        #       when the user presses the Enter key ]
        self.__entryVar  =  StringVar()
        self.__entry  =  Entry ( self, relief=SUNKEN,
            font=BUTTON_FONT,
            width=self.NAME_WIDTH,
            textvariable=self.__entryVar )
        rowx  +=  1
        self.__entry.grid ( row=rowx, column=0, sticky=W )
        self.__entry.bind ( "<Key-Return>", self.__entryHandler )

Placing the label for the color pick list is straightforward. However, creating the color pick list is pretty involved, so that logic is located in Section 14, “class PickList: The color names pick list”.

        #-- 3 --
        # [ self  :=  self with a Label added for the color pick list
        #   self.__pickLabel  :=  that Label ]
        self.__pickLabel  =  Label ( self,
            font=BUTTON_FONT,
            text="Or click on a name:" )
        rowx  +=  1
        self.__pickLabel.grid ( row=rowx, column=0, sticky=W )

        #-- 4 --
        # [ self  :=  self with a PickList added containing
        #       the color pick list, with bindings that will call
        #       self.__callback when a color is clicked
        #   self.__pickList  :=  that ScrolledList ]
        self.__pickList  =  PickList ( self, self.__pickListHandler )
        rowx  +=  1
        self.__pickList.grid ( row=rowx, column=0, sticky=W )