#!/usr/bin/python
# -*- coding: utf-8 -*-

# Urwid SàT extensions
# Copyright (C) 2009, 2010, 2011, 2012, 2013  Jérôme Poisson (goffi@goffi.org)
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation, either version 3 of the License, 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 Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import urwid
from logging import debug, info, warning, error
import encodings
utf8decode = lambda s: encodings.codecs.utf_8_decode(s)[0]

from urwid.util import is_mouse_press #XXX: is_mouse_press is not included in urwid in 1.0.0


class AdvancedEdit(urwid.Edit):
    """Edit box with some custom improvments
    new chars:
              - C-a: like 'home'
              - C-e: like 'end'
              - C-k: remove everything on the right of the cursor
              - C-w: remove the word on the back
    new behaviour: emit a 'click' signal when enter is pressed"""
    signals = urwid.Edit.signals + ['click']

    def setCompletionMethod(self, callback):
        """Define method called when completion is asked
        @callback: method with 2 arguments:
                    - the text to complete
                    - if there was already a completion, a dict with
                        - 'completed':last completion
                        - 'completion_pos': cursor position where the completion starts
                        - 'position': last completion cursor position
                      this dict must be used (and can be filled) to find next completion)
                   and which return the full text completed"""
        self.completion_cb = callback
        self.completion_data = {}

    def keypress(self, size, key):
        #TODO: insert mode is not managed yet
        if key == 'ctrl a':
            key = 'home'
        elif key == 'ctrl e':
            key = 'end'
        elif key == 'ctrl k':
            self._delete_highlighted()
            self.set_edit_text(self.edit_text[:self.edit_pos])
        elif key == 'ctrl w':
            before = self.edit_text[:self.edit_pos]
            pos = before.rstrip().rfind(" ")+1
            self.set_edit_text(before[:pos] + self.edit_text[self.edit_pos:])
            self.set_edit_pos(pos)
        elif key == 'enter':
            self._emit('click')
        elif key == 'shift tab':
            try:
                before = self.edit_text[:self.edit_pos]
                if self.completion_data:
                    if (not self.completion_data['completed']
                        or self.completion_data['position'] != self.edit_pos
                        or not before.endswith(self.completion_data['completed'])):
                        self.completion_data.clear()
                    else:
                        before = before[:-len(self.completion_data['completed'])]
                complet = self.completion_cb(before, self.completion_data)
                self.completion_data['completed'] = complet[len(before):]
                self.set_edit_text(complet+self.edit_text[self.edit_pos:])
                self.set_edit_pos(len(complet))
                self.completion_data['position'] = self.edit_pos
                return
            except AttributeError:
                #No completion method defined
                pass
        return super(AdvancedEdit, self).keypress(size, key)

class Password(AdvancedEdit):
    """Edit box which doesn't show what is entered (show '*' or other char instead)"""

    def __init__(self, *args, **kwargs):
        """Same args than Edit.__init__ with an additional keyword arg 'hidden_char'
        @param hidden_char: char to show instead of what is actually entered: default '*'
        """
        self.hidden_char=kwargs['hidden_char'] if kwargs.has_key('hidden_char') else '*'
        self.__real_text=''
        super(Password, self).__init__(*args, **kwargs)

    def set_edit_text(self, text):
        self.__real_text = text
        hidden_txt = len(text)*'*'
        super(Password, self).set_edit_text(hidden_txt)

    def get_edit_text(self):
        return self.__real_text

    def insert_text(self, text):
        self._edit_text = self.__real_text
        super(Password,self).insert_text(text)

    def render(self, size, focus=False):
        return super(Password, self).render(size, focus)

class ModalEdit(AdvancedEdit):
    """AdvancedEdit with vi-like mode management
    - there is a new 'mode' property which can be changed with properties
    specified during init
    - completion callback received a new 'mode' argument
    """

    def __init__(self, modes, *args, **kwargs):
        """ first argument is "modes", others are the same paramaters as AdvancedEdit
        @param modes: dictionnary in the form:
                      'key_to_change_mode': ('Mode', caption)
                      e.g.: 'i': ('INSERTION', '> ')
                      There *MUST* be a None key (for NORMAL mode)"""
        assert(isinstance(modes, dict) and None in modes)
        self._modes = modes
        super(ModalEdit, self).__init__(*args, **kwargs)
        self.mode = self._modes[None][0]

    @property
    def mode(self):
        return self._mode

    @mode.setter
    def mode(self, value):
        mode_key = None
        for key in self._modes:
            if self._modes[key][0] == value:
                mode_key = key
                break

        mode, caption = self._modes[mode_key]
        self._mode = mode
        self.set_caption(caption)
        if not mode_key: #we are in NORMAL mode
            self.set_edit_text('')

    def setCompletionMethod(self, callback):
        """ Same as AdvancedEdit.setCompletionMethod, but with a third argument: current mode"""
        super(ModalEdit, self).setCompletionMethod(lambda text,data: callback(text, data, self._mode))

    def keypress(self, size, key):
        if key == 'esc':
            self.mode = "NORMAL"
            return
        if self._mode == 'NORMAL' and key in self._modes:
            self.mode = self._modes[key][0]
            return
        return super(ModalEdit, self).keypress(size, key)

class SurroundedText(urwid.Widget):
    """Text centered on a repeated character (like a Divider, but with a text in the center)"""
    _sizing = frozenset(['flow'])

    def __init__(self,text,car=utf8decode('─')):
        self.text=text
        self.car=car

    def rows(self,size,focus=False):
        return self.display_widget(size, focus).rows(size, focus)

    def render(self, size, focus=False):
        return self.display_widget(size, focus).render(size, focus)

    def display_widget(self, size, focus):
        (maxcol,) = size
        middle = (maxcol-len(self.text))/2
        render_text = middle * self.car + self.text + (maxcol - len(self.text) - middle) * self.car
        return urwid.Text(render_text)

class SelectableText(urwid.WidgetWrap):
    """Text which can be selected with space"""
    signals = ['change']

    def __init__(self, text, align='left', header='', focus_attr='default_focus', selected_text=None, selected=False, data=None):
        """@param text: same as urwid.Text's text parameter
        @param align: same as urwid.Text's align parameter
        @select_attr: attrbute to use when selected
        @param selected: is the text selected ?"""
        self.focus_attr = focus_attr
        self.__selected = False
        self.__was_focused = False
        self.header = self.__valid_text(header)
        self.default_txt = self.__valid_text(text)
        urwid.WidgetWrap.__init__(self, urwid.Text("",align=align))
        self.setSelectedText(selected_text)
        self.setState(selected)

    def __valid_text(self, text):
        """Tmp method needed until dbus and urwid are more friends"""
        if isinstance(text, ListOption):
            return text
        if isinstance(text,basestring):
            return unicode(text)
        elif isinstance(text,tuple):
            return (unicode(text[0]),text[1])
        elif isinstance(text,list):
            for idx in range(len(text)):
                elem = text[idx]
                if isinstance(elem,basestring):
                    text[idx] = unicode(elem)
                if isinstance(elem,tuple):
                    text[idx] = (unicode(elem[0]),elem[1])
        else:
            warning (_('WARNING: unknown text type'))
        return text

    def getValue(self):
        if isinstance(self.default_txt,basestring):
            return self.default_txt
        list_attr = self.default_txt if isinstance(self.default_txt, list) else [self.default_txt]
        txt = ""
        for attr in list_attr:
            if isinstance(attr,tuple):
                txt+=attr[1]
            else:
                txt+=attr
        return txt

    def get_text(self):
        """for compatibility with urwid.Text"""
        return self.getValue()

    def set_text(self, text):
        """/!\ set_text doesn't change self.selected_txt !"""
        self.default_txt = self.__valid_text(text)
        self.setState(self.__selected,invisible=True)

    def setSelectedText(self, text=None):
        """Text to display when selected
        @text: text as in urwid.Text or None for default value"""
        if text == None:
            text = ('selected',self.getValue())
        self.selected_txt = self.__valid_text(text)
        if self.__selected:
            self.setState(self.__selected)


    def __set_txt(self):
        txt_list = [self.header]
        txt = self.selected_txt if self.__selected else self.default_txt
        if isinstance(txt,list):
            txt_list.extend(txt)
        else:
            txt_list.append(txt)
        self._w.base_widget.set_text(txt_list)


    def setState(self, selected, invisible=False):
        """Change state
        @param selected: boolean state value
        @param invisible: don't emit change signal if True"""
        assert(type(selected)==bool)
        self.__selected=selected
        self.__set_txt()
        self.__was_focused = False
        self._invalidate()
        if not invisible:
            self._emit("change", self.__selected)

    def getState(self):
        return self.__selected

    def selectable(self):
        return True

    def keypress(self, size, key):
        if key==' ' or key=='enter':
            self.setState(not self.__selected)
        else:
            return key

    def mouse_event(self, size, event, button, x, y, focus):
        if is_mouse_press(event) and button == 1:
            self.setState(not self.__selected)
            return True

        return False

    def render(self, size, focus=False):
        attr_list = self._w.base_widget._attrib
        if not focus:
            if self.__was_focused:
                self.__set_txt()
                self.__was_focused = False
        else:
            if not self.__was_focused:
                if not attr_list:
                    attr_list.append((self.focus_attr,len(self._w.base_widget.text)))
                else:
                    for idx in range(len(attr_list)):
                        attr,attr_len = attr_list[idx]
                        if attr == None:
                            attr = self.focus_attr
                            attr_list[idx] = (attr,attr_len)
                        else:
                            if not attr.endswith('_focus'):
                                attr+="_focus"
                                attr_list[idx] = (attr,attr_len)
                self._w.base_widget._invalidate()
                self.__was_focused = True #bloody ugly hack :)
        return self._w.render(size, focus)

class ClickableText(SelectableText):
    signals = SelectableText.signals + ['click']

    def setState(self, selected, invisible=False):
        super(ClickableText,self).setState(False,True)
        if not invisible:
            self._emit('click')

class CustomButton(ClickableText):

    def __init__(self, label, on_press=None, user_data=None, left_border = "[ ", right_border = " ]"):
        self.label = label
        self.left_border = left_border
        self.right_border = right_border
        super(CustomButton, self).__init__([left_border, label, right_border])
        self.size = len(self.get_text())
        if on_press:
            urwid.connect_signal(self, 'click', on_press, user_data)

    def getSize(self):
        """Return representation size of the button"""
        return self.size

    def get_label(self):
        return self.label[1] if isinstance(self.label,tuple) else self.label

    def set_label(self, label):
        self.label = label
        self.set_text([self.left_border, label, self.right_border])

class ListOption(unicode):
    """ Class similar to unicode, but which make the difference between value and label
    label is show when use as unicode, the .value attribute contain the actual value
    Can be initialised with:
        - basestring (label = value = given string)
        - a tuple with (value, label)
    XXX: comparaison is made again value, not the label which is the one displayed

    """

    def __new__(cls, option):
        if (isinstance(option, cls)):
            return option
        elif isinstance(option, basestring):
            value = label = option
        elif (isinstance(option, tuple) and len(option) == 2):
            value, label = option
        else:
            raise NotImplementedError
        if not value:
            raise ValueError("value can't be empty")
        if not label:
            label = value
        instance = super(ListOption, cls).__new__(cls, label)
        instance._value = value
        return instance

    def __eq__(self, other):
        # XXX: try to compare values, if other has no value
        #      (e.g. unicode string) try to compare to other itself
        try:
            return self._value == other._value
        except AttributeError:
            return self._value == other

    def __ne__(self, other):
        # XXX: see __eq__
        try:
            return self._value != other._value
        except AttributeError:
            return self._value != other

    @property
    def value(self):
        """ return option value """
        return self._value

    @value.setter
    def value(self, value):
        self._value = value

    @staticmethod
    def fromOptions(options):
        """ convert a list of string/tuple options to a list of listOption
        @param options: list of managed option type (basestring, tuple)
        return: list of ListOption
        """
        return [(ListOption(option)) for option in options]


class GenericList(urwid.WidgetWrap):
    signals = ['click','change']

    def __init__(self, options, style=[], align='left', option_type = SelectableText, on_click=None, on_change=None, user_data=None):
        """
        Widget managing list of string and their selection
        @param options: list of strings used for options
        @param style: list of string:
            - 'single' if only one must be selected
            - 'no_first_select' nothing selected when list is first displayed
            - 'can_select_none' if we can select nothing
        @param align: alignement of text inside the list
        @param on_click: method called when click signal is emited
        @param user_data: data sent to the callback for click signal
        """
        self.single = 'single' in style
        self.no_first_select = 'no_first_select' in style
        self.can_select_none = 'can_select_none' in style
        self.align = align
        self.option_type = option_type
        self.first_display = True

        if on_click:
            urwid.connect_signal(self, 'click', on_click, user_data)

        if on_change:
            urwid.connect_signal(self, 'change', on_change, user_data)

        self.content = urwid.SimpleListWalker([])
        self.list_box = urwid.ListBox(self.content)
        urwid.WidgetWrap.__init__(self, self.list_box)
        self.changeValues(options)

    def __onStateChange(self, widget, selected):
        if self.single:
            if not selected and not self.can_select_none:
                #if in single mode, it's forbidden to unselect a value
                widget.setState(True, invisible=True)
                return
            if selected:
                self.unselectAll(invisible=True)
                widget.setState(True, invisible=True)
        self._emit("change")

    def __onClick(self, widget):
        self._emit("click", widget)

    def unselectAll(self, invisible=False):
        for widget in self.content:
            if widget.getState():
                widget.setState(False, invisible)
                widget._invalidate()

    def deleteValue(self, value):
        """Delete the first value equal to the param given"""
        for widget in self.content:
            if widget.getValue() == value:
                self.content.remove(widget)
                self._emit('change')
                return
        raise ValueError("%s ==> %s" %  (str(value),str(self.content)))

    def getSelectedValue(self):
        """Convenience method to get the value selected as a string in single mode, or None"""
        values = self.getSelectedValues()
        return values[0] if values else None

    def getAllValues(self):
        """Return values of all items"""
        return [widget.getValue() for widget in self.content]

    def getSelectedValues(self):
        """Return values of selected items"""
        result = []
        for widget in self.content:
            if widget.getState():
                result.append(widget.getValue())
        return result

    def getDisplayWidget(self):
        return self.list_box

    def changeValues(self, new_values):
        """Change all values in one shot"""
        new_values = ListOption.fromOptions(new_values)
        if not self.first_display:
            old_selected = self.getSelectedValues()
        widgets = []
        for option in new_values:
            widget = self.option_type(option, self.align)
            if not self.first_display and option in old_selected:
                widget.setState(True)
            widgets.append(widget)
            for signal, callback in (('change', self.__onStateChange), ('click', self.__onClick)):
                try:
                    urwid.connect_signal(widget, signal, callback)
                except NameError:
                    pass #the widget given doesn't support the signal
        self.content[:] = widgets
        if self.first_display and self.single and new_values and not self.no_first_select:
            self.content[0].setState(True)
        display_widget = self.getDisplayWidget()
        self._set_w(display_widget)
        self._emit('change')
        self.first_display = False

    def selectValue(self, value):
        """Select the first item which has the given value"""
        self.unselectAll()
        idx = 0
        for widget in self.content:
            if widget.getValue() == value:
                widget.setState(True)
                self.list_box.set_focus(idx)
                return
            idx+=1

class List(urwid.Widget):
    """FlowWidget list, same arguments as GenericList, with an additional one 'max_height'"""
    signals = ['click','change']
    _sizing = frozenset(['flow'])

    def __init__(self, options, style=[], max_height=5, align='left', option_type = SelectableText, on_click=None, on_change=None, user_data=None):
        self.genericList = GenericList(options, style, align, option_type, on_click, on_change, user_data)
        self.max_height = max_height

    def selectable(self):
        return True

    def keypress(self, size, key):
        return self.displayWidget(size,True).keypress(size, key)

    def unselectAll(self, invisible=False):
        return self.genericList.unselectAll(invisible)

    def deleteValue(self, value):
        return self.genericList.deleteValue(value)

    def getSelectedValue(self):
        return self.genericList.getSelectedValue()

    def getAllValues(self):
        return self.genericList.getAllValues()

    def getSelectedValues(self):
        return self.genericList.getSelectedValues()

    def changeValues(self, new_values):
        return self.genericList.changeValues(new_values)

    def selectValue(self, value):
        return self.genericList.selectValue(value)

    def render(self, size, focus=False):
        return self.displayWidget(size, focus).render(size, focus)

    def rows(self, size, focus=False):
        return self.displayWidget(size, focus).rows(size, focus)

    def displayWidget(self, size, focus):
        list_size = sum([wid.rows(size, focus) for wid in self.genericList.content])
        height = min(list_size,self.max_height) or 1
        return urwid.BoxAdapter(self.genericList, height)

## MISC ##

class NotificationBar(urwid.WidgetWrap):
    """Bar used to show misc information to user"""
    signals = ['change']

    def __init__(self):
        self.waitNotifs = urwid.Text('')
        self.message = ClickableText('')
        urwid.connect_signal(self.message, 'click', lambda wid: self.showNext())
        self.progress = ClickableText('')
        self.columns = urwid.Columns([('fixed',6,self.waitNotifs),self.message,('fixed',4,self.progress)])
        urwid.WidgetWrap.__init__(self, urwid.AttrMap(self.columns,'notifs'))
        self.notifs = []

    def __modQueue(self):
        """must be called each time the notifications queue is changed"""
        self.waitNotifs.set_text(('notifs',"(%i)" % len(self.notifs) if self.notifs else ''))
        self._emit('change')

    def setProgress(self,percentage):
        """Define the progression to show on the right side of the bar"""
        if percentage == None:
            self.progress.set_text('')
        else:
            self.progress.set_text(('notifs','%02i%%' % percentage))
        self._emit('change')

    def addPopUp(self, pop_up_widget):
        """Add a popup to the waiting queue"""
        self.notifs.append(('popup',pop_up_widget))
        self.__modQueue()

    def addMessage(self, message):
        "Add a message to the notificatio bar"
        if not self.message.get_text():
            self.message.set_text(('notifs',message))
            self._invalidate()
            self._emit('change')
        else:
            self.notifs.append(('message',message))
            self.__modQueue()

    def showNext(self):
        """Show next message if any, else delete current message"""
        found = None
        for notif in self.notifs:
            if notif[0] == "message":
                found = notif
                break
        if found:
            self.notifs.remove(found)
            self.message.set_text(('notifs',found[1]))
            self.__modQueue()
        else:
            self.message.set_text('')
            self._emit('change')

    def getNextPopup(self):
        """Return next pop-up and remove it from the queue
        @return: pop-up or None if there is no more in the queue"""
        ret = None
        for notif in self.notifs:
            if notif[0] == 'popup':
                ret = notif[1]
                break
        if ret:
            self.notifs.remove(notif)
            self.__modQueue()
        return ret

    def isQueueEmpty(self):
        return not bool(self.notifs)

    def canHide(self):
        """Return True if there is now important information to show"""
        return self.isQueueEmpty() and not self.message.get_text() and not self.progress.get_text()


class MenuBox(urwid.WidgetWrap):
    """Show menu items of a category in a box"""
    signals = ['click']

    def __init__(self,parent,items):
        self.parent = parent
        self.selected = None
        content = urwid.SimpleListWalker([ClickableText(('menuitem',text)) for text in items])
        for wid in content:
            urwid.connect_signal(wid, 'click', self.onClick)

        self.listBox = urwid.ListBox(content)
        menubox = urwid.LineBox(urwid.BoxAdapter(self.listBox,len(items)))
        urwid.WidgetWrap.__init__(self,menubox)

    def getValue(self):
        return self.selected

    def keypress(self, size, key):
        if key=='up':
            if self.listBox.get_focus()[1] == 0:
                self.parent.keypress(size, key)
        elif key=='left' or key=='right':
            self.parent.keypress(size,'up')
            self.parent.keypress(size,key)
        return super(MenuBox,self).keypress(size,key)

    def mouse_event(self, size, event, button, x, y, focus):
        if button == 3:
            self.parent.keypress(size,'up')
            return True
        return super(MenuBox,self).mouse_event(size, event, button, x, y, focus)

    def onClick(self, wid):
        self.selected = wid.getValue()
        self._emit('click')

class Menu(urwid.WidgetWrap):

    def __init__(self,loop, x_orig=0):
        """Menu widget
        @param loop: main loop of urwid
        @param x_orig: absolute start of the abscissa
        """
        self.loop = loop
        self.menu_keys = []
        self.menu = {}
        self.x_orig = x_orig
        self.shortcuts = {} #keyboard shortcuts
        self.save_bottom = None
        col_rol = ColumnsRoller()
        urwid.WidgetWrap.__init__(self, urwid.AttrMap(col_rol,'menubar'))

    def selectable(self):
        return True

    def getMenuSize(self):
        """return the current number of categories in this menu"""
        return len(self.menu_keys)

    def setOrigX(self, orig_x):
        self.x_orig = orig_x

    def __buildOverlay(self,menu_key,columns):
        """Build the overlay menu which show menuitems
        @param menu_key: name of the category
        @colums: column number where the menubox must be displayed"""
        max_len = 0
        for item in self.menu[menu_key]:
            if len(item[0]) > max_len:
                max_len = len(item[0])

        self.save_bottom = self.loop.widget
        menu_box = MenuBox(self,[item[0] for item in self.menu[menu_key]])
        urwid.connect_signal(menu_box, 'click', self.onItemClick)

        self.loop.widget = urwid.Overlay(urwid.AttrMap(menu_box,'menubar'),self.save_bottom,('fixed left', columns),max_len+2,('fixed top',1),None)

    def keypress(self, size, key):
        if key == 'down':
            key = 'enter'
        elif key == 'up':
            if  self.save_bottom:
                self.loop.widget = self.save_bottom
                self.save_bottom = None

        return self._w.base_widget.keypress(size, key)

    def checkShortcuts(self, key):
        for shortcut in self.shortcuts.keys():
            if key == shortcut:
                category, item, callback = self.shortcuts[shortcut]
                callback((category, item))
        return key

    def addMenu(self, category, item, callback, shortcut=None):
        """Add a menu item, create the category if new
        @param category: category of the menu (e.g. File/Edit)
        @param item: menu item (e.g. new/close/about)
        @callback: method to call when item is selected"""
        if not category in self.menu.keys():
            self.menu_keys.append(category)
            self.menu[category] = []
            button = CustomButton(('menubar',category), self.onCategoryClick,
                                   left_border = ('menubar',"[ "),
                                   right_border = ('menubar'," ]"))
            self._w.base_widget.addWidget(button,button.getSize())
        self.menu[category].append((item, callback))
        if shortcut:
            assert(shortcut not in self.shortcuts.keys())
            self.shortcuts[shortcut] = (category, item, callback)

    def onItemClick(self, widget):
        category = self._w.base_widget.getSelected().get_label()
        item = widget.getValue()
        callback = None
        for menu_item in self.menu[category]:
            if item == menu_item[0]:
                callback = menu_item[1]
                break
        if callback:
            self.keypress(None,'up')
            callback((category, item))

    def onCategoryClick(self, button):
        self.__buildOverlay(button.get_label(),
                            self.x_orig + self._w.base_widget.getStartCol(button))


class MenuRoller(urwid.WidgetWrap):

    def __init__(self,menus_list):
        """Create a MenuRoller
        @param menus_list: list of tuple with (name, Menu_instance), name can be None
        """
        assert (menus_list)
        self.selected = 0
        self.name_list = []
        self.menus = {}

        self.columns = urwid.Columns([urwid.Text(''),urwid.Text('')])
        urwid.WidgetWrap.__init__(self, self.columns)

        for menu_tuple in menus_list:
            name,menu = menu_tuple
            self.addMenu(name, menu)

    def __showSelected(self):
        """show menu selected"""
        name_txt = u'\u21c9 '+self.name_list[self.selected]+u' \u21c7 '
        current_name = ClickableText(name_txt)
        name_len = len(name_txt)
        current_menu = self.menus[self.name_list[self.selected]]
        current_menu.setOrigX(name_len)
        self.columns.contents[0] = (current_name, ('given', name_len, False))
        self.columns.contents[1] = (current_menu, ('weight', 1, False))

    def keypress(self, size, key):
        if key=='up':
            if self.columns.get_focus_column()==0 and self.selected > 0:
                self.selected -= 1
                self.__showSelected()
        elif key=='down':
            if self.columns.get_focus_column()==0 and self.selected < len(self.name_list)-1:
                self.selected += 1
                self.__showSelected()
        elif key=='right':
            if self.columns.get_focus_column()==0 and \
                (isinstance(self.columns.contents[1][0], urwid.Text) or \
                self.menus[self.name_list[self.selected]].getMenuSize()==0):
                return #if we have no menu or the menu is empty, we don't go the right column

        return super(MenuRoller, self).keypress(size, key)

    def addMenu(self, name_param, menu):
        name = name_param or ''
        if name not in self.name_list:
            self.name_list.append(name)
        self.menus[name] = menu
        if self.name_list[self.selected] == name:
            self.__showSelected() #if we are on the menu, we update it

    def removeMenu(self, name):
        if name in self.name_list:
            self.name_list.remove(name)
        if name in self.menus.keys():
            del self.menus[name]
        self.selected = 0
        self.__showSelected()

    def checkShortcuts(self, key):
        for menu in self.name_list:
            key = self.menus[menu].checkShortcuts(key)
        return key


## DIALOGS ##

class GenericDialog(urwid.WidgetWrap):

    def __init__(self, widgets_lst, title, style=[], **kwargs):
        frame_header = urwid.AttrMap(urwid.Text(title,'center'),'title')

        buttons = None

        if "OK/CANCEL" in style:
            cancel_arg = [kwargs['cancel_value']] if kwargs.has_key('cancel_value') else []
            ok_arg = [kwargs['ok_value']] if kwargs.has_key('ok_value') else []
            buttons = [urwid.Button(_("Cancel"), kwargs['cancel_cb'], *cancel_arg),
                      urwid.Button(_("Ok"), kwargs['ok_cb'], *ok_arg)]
        elif "YES/NO" in style:
            yes_arg = [kwargs['yes_value']] if kwargs.has_key('yes_value') else []
            no_arg = [kwargs['no_value']] if kwargs.has_key('no_value') else []
            buttons = [urwid.Button(_("Yes"), kwargs['yes_cb'], *yes_arg),
                      urwid.Button(_("No"), kwargs['no_cb'], *no_arg)]
        if "OK" in style:
            ok_arg = [kwargs['ok_value']] if kwargs.has_key('ok_value') else []
            buttons = [urwid.Button(_("Ok"), kwargs['ok_cb'], *ok_arg)]
        if buttons:
            buttons_flow = urwid.GridFlow(buttons, max([len(button.get_label()) for button in buttons])+4, 1, 1, 'center')
        body_content = urwid.SimpleListWalker(widgets_lst)
        frame_body = urwid.ListBox(body_content)
        frame = FocusFrame(frame_body, frame_header, buttons_flow if buttons else None, 'footer' if buttons else 'body')
        decorated_frame = urwid.LineBox(frame)
        urwid.WidgetWrap.__init__(self, decorated_frame)



class InputDialog(GenericDialog):
    """Dialog with an edit box"""

    def __init__(self, title, instrucions, style=['OK/CANCEL'], default_txt = '', **kwargs):
        instr_wid = urwid.Text(instrucions+':')
        edit_box = AdvancedEdit(edit_text=default_txt)
        GenericDialog.__init__(self, [instr_wid,edit_box], title, style, ok_value=edit_box, **kwargs)
        self._w.base_widget.set_focus('body')

class ConfirmDialog(GenericDialog):
    """Dialog with buttons for confirm or cancel an action"""

    def __init__(self, title, style=['YES/NO'], **kwargs):
        GenericDialog.__init__(self, [], title, style, **kwargs)

class Alert(GenericDialog):
    """Dialog with just a message and a OK button"""

    def __init__(self, title, message, style=['OK'], **kwargs):
        GenericDialog.__init__(self, [urwid.Text(message, 'center')], title, style, ok_value=None, **kwargs)

## CONTAINERS ##

class ColumnsRoller(urwid.Widget):
    _sizing = frozenset(['flow'])

    def __init__(self, widget_list = None, focus_column=0):
        self.widget_list = widget_list or []
        self.focus_column = focus_column
        self.__start = 0
        self.__next = False

    def addWidget(self, widget, width):
        self.widget_list.append((width,widget))
        if len(self.widget_list) == 1:
            self.set_focus(0)

    def getStartCol(self, widget):
        """Return the column of the left corner of the widget"""
        start_col = 0
        for wid in self.widget_list[self.__start:]:
            if wid[1] == widget:
                return start_col
            start_col+=wid[0]
        return None

    def selectable(self):
        try:
            return self.widget_list[self.focus_column][1].selectable()
        except IndexError:
            return False

    def keypress(self, size, key):
        if key=='left':
            if self.focus_column>0:
                self.focus_column-=1
                self._invalidate()
                return
        if key=='right':
            if self.focus_column<len(self.widget_list)-1:
                self.focus_column+=1
                self._invalidate()
                return
        if self.focus_column<len(self.widget_list):
            return self.widget_list[self.focus_column][1].keypress(size,key)
        return key

    def getSelected(self):
        """Return selected widget"""
        return self.widget_list[self.focus_column][1]

    def set_focus(self, idx):
        if idx>len(self.widget_list)-1:
            idx = len(self.widget_list)-1
        self.focus_column = idx

    def rows(self,size,focus=False):
        return 1

    def __calculate_limits(self, size):
        (maxcol,) = size
        _prev = _next = False
        start_wid = 0
        end_wid = len(self.widget_list)-1

        total_wid = sum([w[0] for w in self.widget_list])
        while total_wid > maxcol:
            if self.focus_column == end_wid:
                if not _prev:
                    total_wid+=1
                    _prev = True
                total_wid-=self.widget_list[start_wid][0]
                start_wid+=1
            else:
                if not _next:
                    total_wid+=1
                    _next = True
                total_wid-=self.widget_list[end_wid][0]
                end_wid-=1

        cols_left = maxcol - total_wid
        self.__start = start_wid #we need to keep it for getStartCol
        return _prev,_next,start_wid,end_wid,cols_left


    def mouse_event(self, size, event, button, x, y, focus):
        (maxcol,)=size

        if is_mouse_press(event) and button == 1:
            _prev,_next,start_wid,end_wid,cols_left = self.__calculate_limits(size)
            if x==0 and _prev:
                self.keypress(size,'left')
                return True
            if x==maxcol-1 and _next:
                self.keypress(size,'right')
                return True

            current_pos = 1 if _prev else 0
            idx = 0
            while current_pos<x and idx<len(self.widget_list):
                width,widget = self.widget_list[idx]
                if x<=current_pos+width:
                    self.focus_column = idx
                    self._invalidate()
                    if not hasattr(widget,'mouse_event'):
                        return False
                    return widget.mouse_event((width,0), event, button,
                        x-current_pos, 0, focus)

                current_pos+=self.widget_list[idx][0]
                idx+=1

        return False

    def render(self, size, focus=False):
        if not self.widget_list:
            return SolidCanvas(" ", size[0], 1)

        _prev,_next,start_wid,end_wid,cols_left = self.__calculate_limits(size)

        idx=start_wid
        render = []

        for width,widget in self.widget_list[start_wid:end_wid+1]:
            _focus = idx == self.focus_column and focus
            render.append((widget.render((width,),_focus),False,_focus,width))
            idx+=1
        if _prev:
            render.insert(0,(urwid.Text([u"◀"]).render((1,),False),False,False,1))
        if _next:
            render.append((urwid.Text([u"▶"],align='right').render((1+cols_left,),False),False,False,1+cols_left))
        else:
            render.append((urwid.SolidCanvas(" "*cols_left, size[0], 1),False,False,cols_left))

        return urwid.CanvasJoin(render)


class FocusFrame(urwid.Frame):
    """Frame which manage 'tab' key"""

    def keypress(self, size, key):
        ret = urwid.Frame.keypress(self, size, key)
        if not ret:
            return

        if key == 'tab':
            focus_list = ('header','body','footer')
            focus_idx = focus_list.index(self.focus_part)
            for i in range(2):
                focus_idx = (focus_idx + 1) % len(focus_list)
                focus_name = focus_list[focus_idx]
                widget = getattr(self,'_'+focus_name)
                if widget!=None and widget.selectable():
                    self.set_focus(focus_name)

        return ret

class TabsContainer(urwid.WidgetWrap):
    signals = ['click']

    def __init__(self):
        self._current_tab = None
        self._buttons_cont = ColumnsRoller()
        self.tabs = []
        self.__frame = FocusFrame(urwid.Filler(urwid.Text('')),urwid.Pile([self._buttons_cont,urwid.Divider(u"─")]))
        urwid.WidgetWrap.__init__(self, self.__frame)

    def keypress(self, size, key):
        if key=='tab':
            self._w.keypress(size,key)
            return
        return self._w.keypress(size,key)

    def __buttonClicked(self, button, invisible=False):
        """Called when a button on the tab is changed,
        change the page
        @param button: button clicked
        @param invisible: emit signal only if False"""
        tab_name = button.get_label()
        for tab in self.tabs:
            if tab[0] == tab_name:
                break
        if tab[0] != tab_name:
            error(_("INTERNAL ERROR: Tab not found"))
            assert(False)
        self.__frame.body = tab[1]
        button.set_label(('title',button.get_label()))
        if self._current_tab:
            self._current_tab.set_label(self._current_tab.get_label())
        self._current_tab = button
        if not invisible:
            self._emit('click')

    def __appendButton(self, name):
        """Append a button to the frame header,
        and link it to the page change method"""
        button = CustomButton(name, self.__buttonClicked, left_border = '', right_border=' | ')
        self._buttons_cont.addWidget(button, button.getSize())
        if len(self._buttons_cont.widget_list) == 1:
            #first button: we set the focus and the body
            self._buttons_cont.set_focus(0)
            self.__buttonClicked(button,True)

    def addTab(self,name,content=[]):
        """Add a page to the container
        @param name: name of the page (what appear on the tab)
        @param content: content of the page
        @return: ListBox (content of the page)"""
        listbox = urwid.ListBox(urwid.SimpleListWalker(content))
        self.tabs.append([name,listbox])
        self.__appendButton(name)
        return listbox

    def addFooter(self, widget):
        """Add a widget on the bottom of the tab (will be displayed on all pages)
        @param widget: FlowWidget"""
        self._w.footer = widget


## DECORATORS ##
class LabelLine(urwid.LineBox):
    """Like LineBox, but with a Label centered in the top line"""

    def __init__(self, original_widget, label_widget):
        urwid.LineBox.__init__(self, original_widget)
        top_columns = self._w.widget_list[0]
        top_columns.widget_list[1] = label_widget

class VerticalSeparator(urwid.WidgetDecoration, urwid.WidgetWrap):
    def __init__(self, original_widget, left_char = u"│", right_char = ''):
        """Draw a separator on left and/or right of original_widget."""

        widgets = [original_widget]
        if left_char:
            widgets.insert(0, ('fixed', 1, urwid.SolidFill(left_char)))
        if right_char:
            widgets.append(('fixed', 1, urwid.SolidFill(right_char)))
        columns = urwid.Columns(widgets, box_columns = [0,2], focus_column = 1)
        urwid.WidgetDecoration.__init__(self, original_widget)
        urwid.WidgetWrap.__init__(self, columns)