# Copyright (C) 2007 - Nando Vieira
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2, or (at your option)
# any later version.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

import gedit
import gtk
import gtk.gdk
import os
import os.path
from gettext import gettext as _

def debug(text):
    if os.environ.has_key('TN_DEBUG') and os.environ['TN_DEBUG'] == '1':
        print "[tab_navigation] %s" % text

class TabNavigationPlugin(gedit.Plugin):
    def __init__(self):
        gedit.Plugin.__init__(self)
        self.instances = {}

    def activate(self, window):
        debug('activating plugin')
        self.instances[window] = TabNavigationWindowHelper(self, window)

    def deactivate(self, window):
        debug('deactivating plugin')
        self.instances[window].deactivate()
        del self.instances[window]

    def update_ui(self, window):
        debug('updating ui')
        self.instances[window].update_ui()

class TabNavigationWindowHelper:
    handlers = {}
    
    def __init__(self, plugin, window):
        self.window = window
        window.connect('key-press-event', self.on_key_press)
    
    def deactivate(self):
        debug('deactivate function called')
        
        self.window.disconnect_by_func(self.on_key_press)
        self.window = None
        self.plugin = None
    
    def update(self, text=None):
        pass
    
    def update_ui(self):
        pass
    
    def on_key_press(self, view, event):
        ctrl = False
        shift = False
        alt = False
        tab = False
        pgdown = False
        pgup = False
        left = False
        right = False
        
        if event.state & gtk.gdk.CONTROL_MASK:
            ctrl = True
        
        if event.state & gtk.gdk.SHIFT_MASK:
            shift = True
        
        if event.state & gtk.gdk.MOD1_MASK:
            alt = True
        
        if event.keyval == gtk.keysyms.Tab:
            tab = True
        
        if event.keyval == gtk.keysyms.Page_Down:
            pgdown = True
        
        if event.keyval == gtk.keysyms.Page_Up:
            pgup = True
        
        if event.keyval == gtk.keysyms.Left:
            left = True
        
        if event.keyval == gtk.keysyms.Right:
            right = True
        
        if(ctrl and shift and tab) or (ctrl and pgup) or (alt and left):
            self.go_to('previous')
            return True
        elif (ctrl and tab) or (ctrl and pgdown) or (alt and right):
            self.go_to('next')
            return True
        
        return False
    
    def go_to(self, way):
        debug('going to %s tab' % way)
        notebook = self.window.get_active_tab().get_parent()
        total_tabs = notebook.get_n_pages()
        current_tab = notebook.get_current_page()
        
        if total_tabs <= 1:
            debug('found just %d tab' % total_tabs)
            return
        
        if way == 'next':
            if current_tab == total_tabs-1:
                tab = 0
            else:
                tab = current_tab + 1
        else:
            if current_tab == 0:
                tab = total_tabs - 1
            else:
                tab = current_tab - 1
        
        debug('going to tab #%d' % tab)
        notebook.set_current_page(tab)