#!/usr/bin/env python

#****************************************************************************
# recentfiles.py, class to handle recent file lists in menus
#
# Copyright (C) 2005, Douglas W. Bell
#
# This is free software; you can redistribute it and/or modify it under the
# terms of the GNU General Public License, Version 2.  This program is
# distributed in the hope that it will be useful, but WITTHOUT ANY WARRANTY.
#*****************************************************************************

import os.path
from qt import Qt, PYSIGNAL, SIGNAL, SLOT, QObject

class RecentFiles(QObject):
    """Tracks & loads menus with recently opened files"""
    def __init__(self, options, numEntries, maxEntryLen, parent=None, \
                 name=None):
        QObject.__init__(self, parent, name)
        self.options = options
        self.numEntries = numEntries
        self.maxEntryLen = maxEntryLen
        self.menu = None
        self.firstId = 0
        self.separatorId = 0

    def initMenu(self, menu, firstId):
        """load the entries into the menu"""
        self.menu = menu
        self.firstId = firstId
        self.separatorId = self.menu.idAt(self.menu.count() - 1)
        for text, i in zip(self.menuTextList(), range(self.numEntries)):
            self.menu.insertItem(text, self.firstId + i)
        self.connect(self.menu, SIGNAL('activated(int)'), self.openItem)

    def addEntry(self, fileName):
        """Add a new filename to the start of the list"""
        newPath = os.path.abspath(fileName)
        curPath = newPath
        for i in range(self.numEntries):
            tmpPath = self.recentFileName(i)
            self.options.changeData(self.optionTitle(i), curPath, 1)
            curPath = tmpPath
            if curPath == newPath:
                break           # eliminate duplicates
        self.options.writeChanges()
        self.updateMenu()
        self.emit(PYSIGNAL('listChanged'), (self.fileList(),))

    def removeEntry(self, filePath):
        """Remove a filename from the list"""
        allPaths = [self.recentFileName(i) for i in range(self.numEntries)]
        try:
            allPaths.remove(filePath)
        except ValueError:
            return
        allPaths = filter(None, allPaths)
        for i, path in map(None, range(self.numEntries), allPaths):
            self.options.changeData(self.optionTitle(i), path or '', 1)
        self.options.writeChanges()
        self.updateMenu()
        self.emit(PYSIGNAL('listChanged'), (self.fileList(),))

    def openItem(self, id):
        """Signal to main window to open an item"""
        if self.firstId <= id < self.firstId + self.numEntries:
            self.emit(PYSIGNAL('askOpen'), \
                      (self.recentFileName(id - self.firstId),))

    def firstPath(self):
        """Return the first valid path from the recent file list"""
        for num in range(self.numEntries):
            path = os.path.dirname(self.recentFileName(num))
            if os.path.exists(path):
                return path
        return ''

    def updateMenu(self):
        """Refresh menu items"""
        firstIndex = self.menu.indexOf(self.separatorId) + 1
        for text, i in map(None, self.menuTextList(), range(self.numEntries)):
            num = self.menu.indexOf(self.firstId + i)
            if text:
                if num >= 0:
                    self.menu.changeItem(self.firstId + i, text)
                else:
                    self.menu.insertItem(text, self.firstId + i, \
                                         firstIndex + i)
            elif num >= 0:
                self.menu.removeItem(self.firstId + i)

    def changeNumEntries(self, numEntries):
        """Modify number of available entries"""
        for i in range(numEntries, self.numEntries):
            num = self.menu.indexOf(self.firstId + i)
            if num >= 0:
                self.menu.removeItem(self.firstId + i)
            self.options.changeData(self.optionTitle(i), '', 1)
            self.options.changeData('TreeState%d' % (i + 1), '0:0:0:0', 1)
        for i in range(self.numEntries, numEntries):
            self.options.dfltDict[self.optionTitle(i)] = ''
            self.options.dfltDict['TreeState%d' % (i + 1)] = '0:0:0:0'
        self.numEntries = numEntries
        self.options.writeChanges()
        self.updateMenu()

    def optionTitle(self, num):
        """Return option key"""
        return 'RecentFile%d' % (num + 1)

    def recentFileName(self, num):
        """Return file name at num (0-max)"""
        return self.options.strData(self.optionTitle(num), 1)

    def menuTextList(self):
        """Return list of abbreviated path names"""
        return [self.abbreviatePath(path, i) for path, i in \
                zip(self.fileList(), range(self.numEntries)) if path]

    def abbreviatePath(self, path, num):
        """Return abbreviated and numbered path for menu use"""
        if len(path) > self.maxEntryLen:
            pos = path.find('/', len(path) - (self.maxEntryLen - 3))
            if pos < 0:
                pos = len(path) - (self.maxEntryLen - 3)
            path = '...' + path[pos:]
        return '&%d %s' % (num + 1, path)

    def fileList(self):
        """Return the recent files as a list of full paths"""
        return [self.recentFileName(i) for i in range(self.numEntries)]