# Orca
#
# Copyright 2010 Joanmarie Diggs.
#
# This library 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 2.1 of the License, or (at your option) any later version.
#
# This library 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 library; if not, write to the
# Free Software Foundation, Inc., Franklin Street, Fifth Floor,
# Boston MA  02110-1301 USA.

"""Commonly-required utility methods needed by -- and potentially
   customized by -- application and toolkit scripts. They have
   been pulled out from the scripts because certain scripts had
   gotten way too large as a result of including these methods."""

__id__ = "$Id$"
__version__   = "$Revision$"
__date__      = "$Date$"
__copyright__ = "Copyright (c) 2010 Joanmarie Diggs."
__license__   = "LGPL"

import pyatspi

import orca.debug as debug
import orca.script_utilities as script_utilities

#############################################################################
#                                                                           #
# Utilities                                                                 #
#                                                                           #
#############################################################################

class Utilities(script_utilities.Utilities):

    def __init__(self, script):
        """Creates an instance of the Utilities class.

        Arguments:
        - script: the script with which this instance is associated.
        """

        script_utilities.Utilities.__init__(self, script)

    #########################################################################
    #                                                                       #
    # Utilities for finding, identifying, and comparing accessibles         #
    #                                                                       #
    #########################################################################

    def childNodes(self, obj):
        """Gets all of the children that have RELATION_NODE_CHILD_OF pointing
        to this expanded table cell. Overridden here because the object
        which contains the relation is in a hidden column and thus doesn't
        have a column number (necessary for using getAccessibleAt()).

        Arguments:
        -obj: the Accessible Object

        Returns: a list of all the child nodes
        """

        if not self._script.chat.isInBuddyList(obj):
            return script_utilities.Utilities.childNodes(self, obj)

        try:
            table = obj.parent.queryTable()
        except:
            return []
        else:
            if not obj.getState().contains(pyatspi.STATE_EXPANDED):
                return []

        nodes = []        
        index = self.cellIndex(obj)
        row = table.getRowAtIndex(index)
        col = table.getColumnAtIndex(index + 1)
        nodeLevel = self.nodeLevel(obj)
        done = False

        # Candidates will be in the rows beneath the current row.
        # Only check in the current column and stop checking as
        # soon as the node level of a candidate is equal or less
        # than our current level.
        #
        for i in range(row+1, table.nRows):
            cell = table.getAccessibleAt(i, col)
            nodeCell = cell.parent[cell.getIndexInParent() - 1]
            relations = nodeCell.getRelationSet()
            for relation in relations:
                if relation.getRelationType() \
                       == pyatspi.RELATION_NODE_CHILD_OF:
                    nodeOf = relation.getTarget(0)
                    if self.isSameObject(obj, nodeOf):
                        nodes.append(cell)
                    else:
                        currentLevel = self.nodeLevel(nodeOf)
                        if currentLevel <= nodeLevel:
                            done = True
                    break
            if done:
                break

        return nodes

    def nodeLevel(self, obj):
        """Determines the node level of this object if it is in a tree
        relation, with 0 being the top level node.  If this object is
        not in a tree relation, then -1 will be returned. Overridden
        here because the accessible we need is in a hidden column.

        Arguments:
        -obj: the Accessible object
        """

        if not obj:
            return -1

        if not self._script.chat.isInBuddyList(obj):
            return script_utilities.Utilities.nodeLevel(self, obj)

        try:
            obj = obj.parent[obj.getIndexInParent() - 1]
        except:
            return -1

        try:
            table = obj.parent.queryTable()
        except:
            return -1

        nodes = []
        node = obj
        done = False
        while not done:
            relations = node.getRelationSet()
            node = None
            for relation in relations:
                if relation.getRelationType() \
                       == pyatspi.RELATION_NODE_CHILD_OF:
                    node = relation.getTarget(0)
                    break

            # We want to avoid situations where something gives us an
            # infinite cycle of nodes.  Bon Echo has been seen to do
            # this (see bug 351847).
            #
            if (len(nodes) > 100) or nodes.count(node):
                debug.println(debug.LEVEL_WARNING,
                              "pidgin.nodeLevel detected a cycle!!!")
                done = True
            elif node:
                nodes.append(node)
                debug.println(debug.LEVEL_FINEST,
                              "pidgin.nodeLevel %d" % len(nodes))
            else:
                done = True

        return len(nodes) - 1

    #########################################################################
    #                                                                       #
    # Utilities for working with the accessible text interface              #
    #                                                                       #
    #########################################################################



    #########################################################################
    #                                                                       #
    # Miscellaneous Utilities                                               #
    #                                                                       #
    #########################################################################