# a sample graphical user interface using python-gtk

import pygtk
import gtk
import pango

# independent function to add new text to the end of a gtk.TextView:
def addtext(TV,text):
    buffer = TV.get_buffer()
    iter = buffer.get_iter_at_mark(buffer.get_insert())
    buffer.insert(iter,text)   # use "\n" for newlines
# addtext      

class gui1:
    # The init function will set up the graphical layout of the gui:
    def __init__(self,x,y):  # init with x,y position of window
        self.width, self.height = 200,100
        self.window = gtk.Window(gtk.WINDOW_TOPLEVEL)  # create window object
        self.window.set_title("gui1 window")
#        self.window.resize(self.width,self.height)  # best leave alone

        # The principal "box" containing gui elements
        self.mainbox = gtk.VBox(False,20) # 20 pixels between boxes
        self.window.add(self.mainbox)        # add box container to window

        # box to hold gui elements except menu bar
        self.box1 = gtk.HBox(False, 0)    # a verticle "box" of widgets

        # Create GUI elements:
        self.button1 = gtk.Button("OK")       # create button objects
        self.button2 = gtk.Button("Cancel")
        self.text1 = gtk.Entry(32)      # text entry field with max length
        self.check = gtk.CheckButton("Always trust contents from Prof. Liang")
        self.check.set_active(True)  # initially checked
        self.label1 = gtk.Label("this is a label:")
        
        # A multi-line text area must be first added to a scrollwindow:
        sw = gtk.ScrolledWindow()
        self.textarea = gtk.TextView()
        sw.add(self.textarea)
        sw.set_size_request(300,150)  # can use on any "widget"

        # create vertical box for the textview and the label
        self.box2 = gtk.VBox(False,0)
        self.box2.pack_start(self.label1,True,True,5)
        self.box2.pack_start(sw, True, True, 5)
        self.box2.pack_start(self.check,True,True,5)
        
        # "Pack" gui elements into the container "box":
        self.box1.pack_start(self.button1, True, True, 5)
        self.box1.pack_start(self.button2, True, True, 5)
        self.box1.pack_start(self.text1, True, True, 5)
        self.box1.pack_start(self.box2, True, True, 5)        
#        self.box1.pack_start(sw, True, True, 5)        

        # connect events with "callback" functions:
        self.button1.connect("clicked",self.handlerb1)
        self.button2.connect("clicked",self.handlerb2)
        self.check.connect("toggled",self.checkhandler)
        self.window.connect("destroy", lambda w: self.window.destroy())
#       self.window.connect("destroy", lambda w: gtk.main_quit())


        ##### Create a menu bar with "file" and "help" menus
        self.menubar = gtk.MenuBar()

        # Create separate menus
        self.fmenu = gtk.Menu()
        self.hmenu = gtk.Menu()

        #Menu items:
        self.saveitem = gtk.MenuItem("Save")
        self.quititem = gtk.MenuItem("Quit")
        self.infoitem = gtk.MenuItem("About")

        # Add menu items to menus:
        self.fmenu.append(self.saveitem)
        self.fmenu.append(self.quititem)
        self.hmenu.append(self.infoitem)

        # Add menus to menu bar:
        # But this also involves labeling the menus on the menubar:
        filelabel = gtk.MenuItem("File")
        helplabel = gtk.MenuItem("Help")
        filelabel.set_submenu(self.fmenu)
        helplabel.set_submenu(self.hmenu)
        self.menubar.append(filelabel)
        self.menubar.append(helplabel)
        # note that filelabel is a local var - this is ok, since it
        # won't be referred to outside of init

        # Add the entire menubar to the window's main box
        self.mainbox.pack_start(self.menubar,True,True,5)
        self.mainbox.pack_start(self.box1,True,True,5)

        # Connect menu items with callback event handlers
        self.saveitem.connect("activate",self.menuhandler,"save")
        self.quititem.connect("activate",self.menuhandler,"quit")
        self.infoitem.connect("activate",self.menuhandler,"info")
        ##### finally done with the menu!

        self.text1.modify_font(pango.FontDescription("Sans 12")) #set font
        self.text1.grab_focus() # set curor to this widget

        ######################### Show and move main window
        self.window.show_all()  # displays window and all components
        self.window.move(x,y)   # moves window to screen coordinates
                                # move must be called after show_all
        
    # init


    # event handler for the "OK" button:
    def handlerb1(self,widget): # first 2 params are required
        self.text1.set_text("No, it's not OK")
        addtext(self.textarea,"hello there!\n")
    # handlerb1

    def handlerb2(self,widget): # handler for the "cancel" button
        self.text1.set_text("Too late to cancel")
        # self.text1.get_text() will return text found in entry
    # handlerb2

    def checkhandler(self,widget):  # handler for the checkbox
        state = self.check.get_active()
        if state==False:
            addtext(self.textarea,"Boo!\n")
    #checkhandler
        
    def menuhandler(self,widget,source):  # handler for menu
        if source=="save":
            response = "You've done nothing worth saving.\n"
        if source=="quit":
            response = "Why would you want to quit such a nice program?\n"
        if source == "info":
            response = "This is a gui program, can't you tell!\n"
        addtext(self.textarea,response)
    #menuhandler

# gui1 class


# create instances of gui1 class
mygui = gui1(0,0)
yourgui = gui1(400,400)


# The following line starts the gtk "event loop"
gtk.main()