在ubuntu下生成precise.xml桌面图片切换(Desktop Slideshow)

create_precise_xml.py

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

from xml.dom.minidom import Document
import os, glob, random

DOC = Document()  #创建DOM文档对象

def createTime(fnode):
    '''生成starttime节点'''
    starttime = DOC.createElement('starttime')
    addDictNode(starttime, {
        'year': '2009',
        'month': '08',
        'day': '04',
        'hour': '00',
        'minute': '00',
        'second': '00'
    })
    fnode.appendChild(starttime)

def createImgSwap(fnode, paths):
    '''创建图片切换节点'''
    plen = len(paths)
    for i in range(plen):
        if i == plen - 1: inext = 0
        else: inext = i + 1
        
        static = DOC.createElement('static')
        addDictNode(static, {
            'duration': '1795.0',
            'file': paths[i]
        })
        fnode.appendChild(static)

        transition = DOC.createElement('transition')
        addDictNode(transition, {
            'duration': '5.0',
            'from': paths[i],
            'to': paths[inext]
        })
        fnode.appendChild(transition)

def addDictNode(fnode, tagDicts):
    '''通过字典添加多个文本节点'''
    for tagKey in tagDicts.keys():
        tNode = DOC.createElement(tagKey)
        tText = DOC.createTextNode(tagDicts[tagKey])
        tNode.appendChild(tText)
        fnode.appendChild(tNode)
    return fnode

def createPrecise(*filenames):
    '''创建precise的xml文件'''
    background = DOC.createElement('background')
    createTime(background)
    cwd = os.getcwd()
    paths = []
    for filename in filenames:
        paths.extend(glob.glob(filename))
    random.shuffle(paths)
    for i in range(len(paths)):
        paths[i] = cwd + '/' + paths[i]
    createImgSwap(background, paths)
    DOC.appendChild(background)


'''
生成ubuntu所用的precise.xml文件.
利用当前目录下的图片文件
'''

if __name__ == '__main__':
    # 创建并生成precise.xml文件
    createPrecise('*.jpg', '*.png', '*.gif')
    f = open('precise.xml','w')
    f.write(DOC.toprettyxml(indent = ''))
    f.close()
    print('输入密码,替换系统原有的precise.xml')
    os.system('sudo mv -f precise.xml /usr/share/backgrounds/contest/precise.xml')
    raw_input('结束')