使用链接对象的Python菜单

2024-09-27 17:40:04 发布

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我使用Python在Raspberry Pi上显示一个菜单层次结构，用于延时摄影。我使用一个2行x 16字符的LCD和四个按钮<；（转到父菜单）、^（转到上一个同级）、v（转到下一个同级）>；（选择-ie转到第一个子项）。在

这是我第一次使用Python，所以有一堆东西我还不知道。到目前为止，我已经定义了一个menuItem类，其中包含添加和获取名称、父级和其他一些内容的方法。我的困难是知道如何收集儿童菜单集(self.getChildren)或者得到兄弟菜单项(self.get兄弟姐妹)，因此我可以派生层次结构中的下一个和前一个兄弟。到目前为止，层次结构仅由创建顺序和setParent方法暗示。在

我搜索了一下，发现可能有很多方法可以解决这个问题，比如链图？或者菜单课-毫无疑问有更多的方法。有谁能帮我选择一个高效且易于理解的方法吗。（请记住，我是新手，所以“易懂”至少对我来说比简洁复杂要好得多）

到目前为止我的代码（友好：o）

#####################################################################
# A menuItem chains to other menuItems
#####################################################################
class MenuItem: 
    def __init__(self):
        self.children = ''

    #setName: method to give a name to this menu item
    def setName(self, name):
        self.name = name

    #getName: method to report the name of this menu item
    def getName(self):
        return self.name

    #setParent: method to set the parent menu item for this menu item
    def setParent(self, parent):
        self.parent = parent

    #getParent: method to report the parent menu item for this menu item
    def getParent(self):
        return self.parent

    #setPrevious: method to set the previous sibling menu item
#   def setPrevious(self, previous):
#       self.previous = previous

    #getPrevious: method to report the previous sibling menu item
    def getPreviousSibling(self):
        return self.previousSibling

    #setNext: method to set the next sibling menu item
#   def setNext(self, nxt):
#       self.nxt = nxt

    #getNext: method to report the next sibling menu item
    def getNextSibling(self):
        return self.nextSibling

    #setChildren: method to append a new child menuItem
    # to be called from the point of instantiating the child menuItem
    def setChildren(self, appendMenuItem):
        self.children = self.children + ',' + appendMenuItem

    #getChildren: method to report the list of children manu items
    def getChildren(self):
        return self.children

    #getSiblings: method to report the sibling menu items
    def getSiblings(self):
        return self.siblings

    #setDisplayString: method to set the string that will be displayed on the LCD (max 16 characters)
    def setDisplayStringL1(self, displayStringL1):
        self.displayStringL1 = displayStringL1

    #setDisplayString: method to set the string that will be displayed on the LCD (max 16 characters)
    def setDisplayStringL2(self, displayStringL2):
        self.displayStringL2 = displayStringL2

    #getDisplayStringL1: method to report the first string that is displayed on the LCD for this menu item
    def getDisplayStringL1(self):
        return self.displayStringL1

    #getDisplayStringL2: method to report the second string that is displayed on the LCD for this menu item
    def getDisplayStringL2(self):
        return self.displayStringL2

    #setValidValues: method to set valid values (comma delimited)(need to think about how to do ranges or positive integers)
    def setValidValues(self, validValues):
        self.validValues = validValues

    #stringUpdateChars: method to update a section of the display string
    def stringUpdateChars(self,LineNum, startChar, endChar, ValString):
        if LineNum == 1: 
            for i in range (0,(endChar-startChar),1): #there must be a better way to do this!
                self.displayStringL1[startChar+i] = ValString[i]
        elif LineNum == 2:
            for i in range (0,(endChar-startChar),1):
                self.displayStringL2[startChar+i] = ValString[i]


def InitialiseMenu():
    menuitem1 = MenuItem()
    menuitem1.setName('applications')
    menuitem1.setDisplayStringL1('Applications')
    menuitem1.setDisplayStringL2('')
    menuitem1.setParent('none')

    menuitem2 = MenuItem()
    menuitem2.setName('timeLapse')
    menuitem2.setDisplayStringL1('Time Lapse')
    menuitem2.setDisplayStringL2('')
    menuitem2.setParent(menuitem1)

    menuitem3 = MenuItem()
    menuitem3.setName('bulb')
    menuitem3.setDisplayStringL1("Man. Set 'bulb'")
    menuitem3.setDisplayStringL2('')
    menuitem3.setParent(menuitem2)

    menuitem4 = MenuItem()
    menuitem4.setName('exposure')
    menuitem4.setDisplayStringL1("Exp:00 s")
    menuitem4.setDisplayStringL2("E00s")
    menuitem4.setValidValues(1,2,3,4,5,6,7,8,9,10,12,14,16,18,20,25,30,35,40,45,50,60)
    menuitem4.setParent(menuitem3)

    menuitem5 = MenuItem()
    menuitem5.setName('expUnits')
    menuitem5.setDisplayStringL1("Exp:00 s")
    menuitem5.setDisplayStringL2("E00s")
    menuitem5.setValidValues('s','m')
    menuitem5.setParent(menuitem4)

    menuitem6 = MenuItem()
    menuitem6.setName('delay')
    menuitem6.setDisplayStringL1("Delay:00 s")
    menuitem6.setDisplayStringL2("E00s D00s")
    menuitem6.setValidValues(1,2,3,4,5,6,7,8,9,10,12,14,16,18,20,25,30,35,40,45,50,60)
    menuitem6.setParent(menuitem5)

    menuitem7 = MenuItem()
    menuitem7.setName('delayUnits')
    menuitem7.setDisplayStringL1("Delay:00 s")
    menuitem7.setDisplayStringL2("E00s D00s")
    menuitem7.setValidValues('s','m')
    menuitem7.setParent(menuitem6)

    menuitem8 = MenuItem()
    menuitem8.setName('frames')
    menuitem8.setDisplayStringL1("Frames:00000")
    menuitem8.setDisplayStringL2("E00s D00s F0000")
    menuitem8.setParent(menuitem7)

    #--------------------------      

    menuitem9 = MenuItem()
    menuitem9.setName('clipLength')
    menuitem9.setDisplayStringL1("Clip length")
    menuitem9.setDisplayStringL2('')
    menuitem9.setParent(menuitem2)

    menuitem10 = MenuItem()
    menuitem10.setName('clipLengthPeriod')
    menuitem10.getDisplayStringL1("Len:00 s")
    menuitem10.getDisplayStringL2("L:00s")
    menuitem10.setParent(menuitem9)

    menuitem11 = MenuItem()
    menuitem11.setName('clipLengthPeriodUnits')
    menuitem11.getDisplayStringL1("Len:00 s")
    menuitem11.getDisplayStringL2("L:00s")
    menuitem11.setParent(menuitem10)

    menuitem12 = MenuItem()
    menuitem12.setName('fps')
    menuitem12.getDisplayStringL1("FPS:00/s")
    menuitem12.getDisplayStringL2("F:00s fps:00")
    menuitem12.setValidValues(20,21,22,23,24,25,26,27,28,29,30)
    menuitem12.setParent(menuitem11)      

    #--------------------------      
    menuitem13 = MenuItem()
    menuitem13.setName('realTime')
    menuitem13.getDisplayStringL1("Real-time")
    menuitem13.setDisplayStringL2('')
    menuitem13.setParent(menuitem2)

    menuitem14 = MenuItem()
    menuitem14.setName('realTimePeriod')
    menuitem14.getDisplayStringL1("Per:00 s")
    menuitem14.getDisplayStringL2("P:00s")
    menuitem14.setParent(menuitem13)

    menuitem15 = MenuItem()
    menuitem15.setName('realTimePerioddUnits')
    menuitem15.getDisplayStringL1("Per:00 s")
    menuitem15.getDisplayStringL2("P:00s")
    menuitem15.setParent(menuitem14)

    menuitem16 = MenuItem()
    menuitem16.setName('realTimefps')
    menuitem16.getDisplayStringL1("FPS:00/s")
    menuitem16.getDisplayStringL2("f:00s fps:00")
    menuitem16.setValidValues(20,21,22,23,24,25,26,27,28,29,30)
    menuitem16.setParent(menuitem15)      

    menuitem16 = MenuItem()
    menuitem16.setName('startPauseStop')
    menuitem16.setDisplayStringL1("Start")
    menuitem16.setDisplayStringL2("press > to start")
    menuitem16.setParent(menuitem2)      

userInput = 'yes'
#when the other navigation is enabled, I'll set this to menuItem1
currentMenuItem = menuitem8  #<-this is in error - indent problem?
#type 'no' to exit or use <|^|v|> to navigate
#I'm expecting this to keep asking for input. Each time < is pressed it'll print out the name of the parent menuItem up to the root item
while userInput != "no":
    userInput = raw_input("< ^ v >  ")
    #up tree
    if userInput == "<":
        if currentMenuItem.getParent().getName()  != "none":
            currentMenuItem = currentMenuItem.getParent()
            print "current menu item: " + currentMenuItem.getName()
        else:
            print "current menu item: " + currentMenuItem.getName()
#     #previous sibling
#     elif userInput == "^":
#         if currentMenuItem.getParent() != "none":
#             currentMenuItem = currentMenuItem.getParent()
#             print currentMenuItem.getName()
#     #next sibling
#     elif userInput == "v":
#         if currentMenuItem.getParent() != "none":
#             currentMenuItem = currentMenuItem.getParent()
#             print currentMenuItem.getName()
#     #select - first child
#     elif userInput == ">":
#         if currentMenuItem.getParent() != "none":
#             currentMenuItem = currentMenuItem.getParent()
#             print currentMenuItem.getName()
print "Finished!"

Tags： thetoselfdefthisitemmethodmenu
1条回答
网友
1楼 · 发布于 2024-09-27 17:40:04

一种方法是使用一个类属性来保存所有MenuItem实例，然后使用此字典的键（项的名称）在它们之间移动：

class MenuItem(object):

    items = {}

    def __init__(self, name, parent):
        self.name = name
        self._parent = parent
        MenuItem.items[name] = self      

    @property
    def parent(self):
        return MenuItem.items[self._parent]

    @parent.setter
    def set_parent(self, parent):
        if parent in MenuItem.items:
            self._parent = parent
        else:
            raise ValueError

注意使用^{}，它比get和{}更像Python。在

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