I want to show ten lines of 'test' label in one window, so I use the for-loop, but it only shows one line.
I guess the for-loop in my code is put the wrong place, but I don't know how to make it correct.
Here is the main code:
class Home(QMainWindow):
def __init__(self, parent = None):
super(Home, self).__init__(parent)
self.setGeometry(300,100,400,300)
self.scrollLayout = QFormLayout()
self.scrollWidget = QWidget()
self.scrollWidget.setLayout(self.scrollLayout)
self.scrollArea = QScrollArea()
self.scrollArea.setWidgetResizable(True)
self.scrollArea.setWidget(self.scrollWidget)
self.mainLayout = QVBoxLayout()
self.mainLayout.addWidget(self.scrollArea)
self.centralWidget = QWidget()
self.centralWidget.setLayout(self.mainLayout)
self.setCentralWidget(self.centralWidget)
self.Lbl = QLabel('test')
for i in range(20):### here, it only loops 1 time
self.scrollLayout.addRow(self.Lbl)
self.show()
this
1 self.Lbl = QLabel('test')
2 for i in range(20):### here, it only loops 1 time
3 self.scrollLayout.addRow(self.Lbl)
you need to put line 1 actually in the for-loop(line 2...line 3)
The problem is that you are creating only one label known inside your class. Any Widget type (QLabel), can be added only once to any "container". So you are adding the same label 20 times, when you add a label somewhere else or in the same place you remove the old one and add it to the new place, one label cannot be at two places at the same time.
Here is the thing, you have to create one new label each loop so you would have something like that:
for i in range(20):
lbl = QLabel("teste"+str(i)) # here you are creating one new label to each loop
self.scrollLayout.addRow(lbl)
But remember, in this way now you do not have an instance saved in a variable of each label, to access each one you will have to iterate in your scrollLayout and take one by one to modify them.
Another thing you can do is to have a list that you append each of your labels and can easily access them later on.
Related
I have a listctrl,
self.list = wx.ListCtrl(panel, -1, style=wx.LC_REPORT | wx.LC_NO_HEADER)
self.list.InsertColumn(col=0, heading='', format=wx.LIST_FORMAT_CENTER, width=150)
self.list.InsertColumn(col=1, heading='', format=wx.LIST_FORMAT_CENTER, width=450)
for person in people:
#this is the issue right here
index = self.list.InsertItem(0, person.age) #one line to insert an item and get the index, and the next line to update the item at that index... two lines to actually put a full entry in.
self.list.SetItem(index=index, column=1, label=person.name)
This works fine setting up the listctrl initially in the constructor, but what if I want to dynamically add/remove items in the listctrl at runtime?
I've come across wx.CallAfter, wx.CallLater, startWorker (from wx.lib.delayedresult), and wx.Timer
If you look at the example above the issue is that I've got one line that inserts the item, and another line that updates the item to have the correct name on the item that was just inserted. So if I've got threads that are taking turns removing and adding items to the listctrl, if I insert an item and another thread inserts an item at the same time, the index that I just got won't be relevant for updating. i.e. I need an atomic operation for inserting an item that includes inserting both the person's age and the person's name. So my first question is, is there a way to insert all information of a list item in one line?
If I cannot do that, then my next question is how could I accomplish the prescribed behavior? For example, suppose there are threads randomly coloring the top row, adding, and deleting:
self.color_timer = wx.Timer(self)
self.Bind(wx.EVT_TIMER, self.item_colorizer, self.color_timer)
self.red_shown = True
self.color_timer.Start(500)
self.delete_timer = wx.Timer(self)
self.Bind(wx.EVT_TIMER, self.item_deleter, self.delete_timer)
self.delete_timer.Start(500)
self.adder_timer = wx.Timer(self)
self.Bind(wx.EVT_TIMER, self.item_queuer, self.adder_timer)
self.adder_timer.Start(400)
Then here are my methods that are used to add people, delete people, and color the top row:
def item_queuer(self, event):
startWorker(consumer=self.item_adder,
workerFn=self.person_generator)
def person_generator(self):
return {'person':random.choice(people)}
def item_adder(self, result):
res = result.get()
person = res['person']
wx.CallAfter(self.list.InsertItem, 0, person.name) # this is the problem right here. If another thread does a color swap in between this line and the next, then this won't work.
wx.CallAfter(self.list.SetItem, index=0, column=1, label=person.name)
def item_deleter(self, event):
wx.CallAfter(self.list.DeleteItem, 0)
def item_colorizer(self, event):
if self.color_timer.IsRunning():
if not self.red_shown:
wx.CallAfter(self.list.SetItemBackgroundColour, 0, wx.RED)
wx.CallAfter(self.list.SetItemTextColour, 0, wx.WHITE)
self.red_shown = True
else:
wx.CallAfter(self.list.SetItemBackgroundColour, 0, wx.BLUE)
wx.CallAfter(self.list.SetItemTextColour, 0, wx.BLACK)
self.red_shown = False
What actually happens when I run this is that I end up having rows where the person is partially inserted (just the age), and the color changes before the name is inserted. I've noticed that the InsertItem method on the listctrl is overloaded and offers one signature where I can insert a ListItem, but I cannot get that to work either.
item1 = wx.ListItem()
item1.SetBackgroundColour(wx.GREEN)
item1.SetColumn(0)
item1.SetText(32)
item1.SetColumn(1)
item1.SetText('John')
self.list.InsertItem(item1)
wx._core.wxAssertionError: C++ assertion "rv != -1" failed at ....\src\msw\listctrl.cpp(1730) in wxListCtrl::InsertItem(): failed to insert an item in wxListCtrl
I am working on a project that involves creating many instances of Tkinter Labels and Entry widgets that will always be aligned next to one another. To try and save myself time, I created a custom class that I am showing below:
class labelEntry(Label,Entry):
def __init__(self,parent,label,row,column,bg_color):
Label.__init__(self,parent)
self['text']=label
self['justify']='right'
self['bg']=bg_color
self.grid(row=row,column=column, sticky=E)
Entry.__init__(self,parent)
self['width']="10"
self.grid(row=row,column=column+1)
This creates the configuration I want and is easy enough to arrange (I have them stored in a frame). The problem is I don't know how to access the Entry widgets that I have created as they are part of this new class.
I have a desire to read and delete the entries from the entry widgets. My best guess at clearing them was with this button that was being fed into the same frame:
class clearAllEntry(Button):
def clearAll(self,targetFrame):
targetFrame.labelEntry.Entry.delete(0,END)
def __init__(self,parent,targetFrame):
Button.__init__(self,parent,text='Clear All Entries',bg='black',fg='white')
self['command']= "clearAll(targetFrame)"
I have also looked at grid_slave as an approach but am having the same issue.
Any advice/help would be greatly appreciated.
First off, if you're creating a new class that contains two objects of different classes, you should not be using inheritance. Instead, use composition.
Second, to be able to access the entry widget, save it to an instance variable.
For example:
class LabelEntry():
def __init__(self, parent, label, row, column, bg_color):
self.label = Label(parent, text=label, justify='right', bg=bg_color)
self.entry = Entry(parent, width=10)
self.label.grid(row=row, column=column, sticky="e")
self.grid(row=row,column=column+1)
Later, you can reference these attributes like you can any other attribute:
le1 = LabelEntry(root)
...
print(le1.entry.get())
{Edit: the answer by Bryan Oakley in the suggested duplicate question enter link description here a) fires a response on change to the array variable (arrayvar.trace mode="w"), and I need it triggered on FocusOut, as described in my original question; b) works for Python 2, but I'm having trouble converting it to work in Python 3.5. I'm currently using his and pyfunc's answers as leads and trying to figure out a similar solution using a FocusOut event.}
I am working on a tkinter GUI that lets a user select a particular type of calculation, using a pair of radio button lists. Based on the selections, a tool bar is populated with multiple modular entry widgets, one for each variable the calculation requires. The goal is to have the numerical entry values passed to the model, which will return data to be graphed on a canvas or matplotlib widget.
My question is: what typical strategy is used for gathering and continually refreshing values from multiple widgets, in order to update displays and to pass them on to the model? The trick here is that there will be a large number of possible calculation types, each with their own toolbar. I'd like the active toolbar to be "aware" of its contents, and ping the model on every change to a widget entry.
I think the widgets and the toolbar would have to be classes, where the toolbar can query each widget for a fresh copy of its entry values when a change is detected, and store them as some collection that is passed to the model. I'm not entirely sure how it can track changes to the widgets. Using a "validate='focusout' " validation on the entry widget (e.g. as in
this validation reference )
suggests itself, but I already use "validate='key' " to limit all entries to numbers. I don't want to use "validate=all" and piggyback onto it because I don't want to continually ask the model to do a lengthy calculation on every keypress.
I'm new to GUI programming, however, so I may be barking up the wrong tree. I'm sure there must be a standard design pattern to address this, but I haven't found it.
Below is a screenshot of a mockup to illustrate what I want the GUI to do. The Task radiobutton controls which secondary button menu appears below. The selection in the second menu populates the top toolbar with the necessary entry widgets.
The following code does (mostly) what I want. The ToolBar frame objects will store the values from its contained widgets, and call the appropriate model as needed. The VarBox objects are Entry widgets with extra functionality. Hitting Tab or Return refreshes the data stored in the ToolBar dictionary, tells the ToolBar to send data to the model, and shifts focus to the next VarBox widget.
from tkinter import *
# Actual model would be imported. "Dummy" model for testing below.
def dummy_model(dic):
"""
A "dummy" model for testing the ability for a toolbar to ping the model.
Argument:
-dic: a dictionary whose values are numbers.
Result:
-prints the sum of dic's values.
"""
total = 0
for value in dic.values():
total += value
print('The total of the entries is: ', total)
class ToolBar(Frame):
"""
A frame object that contains entry widgets, a dictionary of
their current contents, and a function to call the appropriate model.
"""
def __init__(self, parent=None, **options):
Frame.__init__(self, parent, **options)
self.vars = {}
def call_model(self):
print('Sending to dummy_model: ', self.vars)
dummy_model(self.vars)
class VarBox(Frame):
"""
A customized Frame containing a numerical entry box
Arguments:
-name: Name of the variable; appears above the entry box
-default: default value in entry
"""
def __init__(self, parent=None, name='', default=0.00, **options):
Frame.__init__(self, parent, relief=RIDGE, borderwidth=1, **options)
Label(self, text=name).pack(side=TOP)
self.widgetName = name # will be key in dictionary
# Entries will be limited to numerical
ent = Entry(self, validate='key') # check for number on keypress
ent.pack(side=TOP, fill=X)
self.value = StringVar()
ent.config(textvariable=self.value)
self.value.set(str(default))
ent.bind('<Return>', lambda event: self.to_dict(event))
ent.bind('<FocusOut>', lambda event: self.to_dict(event))
# check on each keypress if new result will be a number
ent['validatecommand'] = (self.register(self.is_number), '%P')
# sound 'bell' if bad keypress
ent['invalidcommand'] = 'bell'
#staticmethod
def is_number(entry):
"""
tests to see if entry is acceptable (either empty, or able to be
converted to a float.)
"""
if not entry:
return True # Empty string: OK if entire entry deleted
try:
float(entry)
return True
except ValueError:
return False
def to_dict(self, event):
"""
On event: Records widget's status to the container's dictionary of
values, fills the entry with 0.00 if it was empty, tells the container
to send data to the model, and shifts focus to the next entry box (after
Return or Tab).
"""
if not self.value.get(): # if entry left blank,
self.value.set(0.00) # fill it with zero
# Add the widget's status to the container's dictionary
self.master.vars[self.widgetName] = float(self.value.get())
self.master.call_model()
event.widget.tk_focusNext().focus()
root = Tk() # create app window
BarParentFrame = ToolBar(root) # holds individual toolbar frames
BarParentFrame.pack(side=TOP)
BarParentFrame.widgetName = 'BarParentFrame'
# Pad out rest of window for visual effect
SpaceFiller = Canvas(root, width=800, height=600, bg='beige')
SpaceFiller.pack(expand=YES, fill=BOTH)
Label(BarParentFrame, text='placeholder').pack(expand=NO, fill=X)
A = VarBox(BarParentFrame, name='A', default=5.00)
A.pack(side=LEFT)
B = VarBox(BarParentFrame, name='B', default=3.00)
B.pack(side=LEFT)
root.mainloop()
I'm very new to threading am and still trying to get my head around how to code most of it. I am trying to make what is effectively a text editor-type input box and so, like every text editor I know, I need a cursor-bar thing to indicate the location at which the text is being typed to. Thus I also want to be able to flicker/blink the cursor, which i thought would also prove good practice for threading.
I have a class cursor that creates a rectangle on the canvas based on the bounding box of my canvas text, but I then need to change it's location as more characters are typed; stop the thread and instantaneously hide the cursor rectangle when the user clicks outside of the input box; and lastly restart the thread/a loop within the thread (once again, sharing a variable) - the idea here being that the cursor blinks 250 times and after then, disappears (though not necessary, I thought it would make a good learning exercise).
So assuming that I have captured the events needed to trigger these, what would be the best way to go about them? I have some code, but I really don't think it will work, and just keeps getting messier. My idea being that the blinking method itself was the thread. Would it be better to make the whole class a thread instead? Please don't feel restricted by the ideas in my code and feel free to improve it. I don't think that the stopping is working correctly because every time I alt+tab out of the window (which i have programmed to disengage from the input box) the Python shell and tkinter GUI stop responding.
from tkinter import *
import threading, time
class Cursor:
def __init__(self, parent, xy):
self.parent = parent
#xy is a tuple of 4 integers based on a text object's .bbox()
coords = [xy[2]] + list(xy[1:])
self.obj = self.parent.create_rectangle(coords)
self.parent.itemconfig(self.obj, state='hidden')
def blink(self):
blinks = 0
while not self.stop blinks <= 250:
self.parent.itemconfig(self.obj, state='normal')
for i in range(8):
time.sleep(0.1)
if self.stop: break
self.parent.itemconfig(self.obj, state='hidden')
time.sleep(0.2)
blinks += 1
self.parent.itemconfig(self.obj, state='hidden')
def startThread(self):
self.stop = False
self.blinking = threading.Thread(target=self.blink, args=[])
self.blinking.start()
def stopThread(self):
self.stop = True
self.blinking.join()
def adjustPos(self, xy):
#I am not overly sure if this will work because of the thread...
coords = [xy[2]] + list(xy[1:])
self.parent.coords(self.obj, coords)
#Below this comment, I have extracted relevant parts of classes to global
#and therefore, it may not be completely syntactically correct nor
#specifically how I initially wrote the code.
def keyPress(e):
text = canvas.itemcget(textObj, text)
if focused:
if '\\x' not in repr(e.char) and len(e.char)>0:
text += e.char
elif e.keysym == 'BackSpace':
text = text[:-1]
canvas.itemconfig(textObj, text=text)
cursor.adjustPos(canvas.bbox(textObj))
def toggle(e):
if cursor.blinking.isAlive(): #<< I'm not sure if that is right?
cursor.stopThread()
else:
cursor.startThread()
if __name__=="__main__":
root = Tk()
canvas = Canvas(root, width=600, height=400, borderwidth=0, hightlightthickness=0)
canvas.pack()
textObj = canvas.create_text(50, 50, text='', anchor=NW)
root.bind('<Key>', keyPress)
cursor = Cursor(canvas, canvas.bbox(textObj))
#Using left-click event to toggle thread start and stop
root.bind('<ButtonPress-1', toggle)
#Using right-click event to somehow restart thread or set blinks=0
#root.bind('<ButtonPress-3', cursor.dosomething_butimnotsurewhat)
root.mainloop()
If there is a better way to do something written above, please also tell me.
Thanks.
SO I am using Python 3.4 and tkinter.
And when I call a function again n again which contains a label, the label keeps on appearing in window but previous label doesn't go away?
How can I remove any printed label from GUI window as soon as function is called and then display new one?
Here is the code:-
#def prestart():
#here I check if number of match is okay, if not, user is redirected to setting else, I call start()
def start():
#CPU Choice
cpu_choice = Label(historyframe, text = "CPU Choosed: {}".format(dict['cpu_choice']))
#Played Match
#played_num_of_match = Label(scoreframe, text = "Number of Matches Played: {}".format(int(dict['match_played'])))
#Display Status
status_disp = Label(scoreframe, text = "Current Status: {}".format(dict['status']))
if(int(dict['match_played']) < int(dict['num_of_match'])):
playframe.grid(row = 1, column = 0)
historyframe.grid(row = 2, column = 1)
status_disp.pack(fill=X)
elif(int(dict['match_played']) == int(dict['num_of_match'])):
playframe.grid(row = 1, column = 0)
historyframe.grid(row = 2, column = 1)
status_disp.pack(fill=X)
cp = dict['cpu_point']
up = dict['user_point']
result(cp, up)
cpu_choice.pack(fill = X)
scoreframe.grid(row = 2, column = 0)
This function just updates the display!
def send_value(x):
#Here I run logic of game and change value of key in dictionary and call start() at end of change.
Now, the choice buttons are not in any definition as they don't need to be called again n again. I just make playframe disappear n appear!
Here is the code for them:-
#Display Question
question = Label(playframe, text = "Rock? Paper? Scissor?")
#Rock
rock = Button(playframe, text = "Rock!", command = lambda: send_value("ROCK"))
#Paper
paper = Button(playframe, text = "Paper!", command = lambda: send_value("PAPER"))
#Scissor
scissor = Button(playframe, text = "Scissor!", command = lambda: send_value("SCISSOR"))
So when user clicks Rock/Paper/Scissor, I just change key value in dictionary! But if I keep the label outside function, it doesn't get auto updated!
Everything else is working perfectly. I'll kind of now start to make code cleaner.
Try something like this instead of creating a new label every time:
import Tkinter as tk
class Window():
def __init__(self, root):
self.frame = tk.Frame(root)
self.frame.pack()
self.i = 0
self.labelVar = tk.StringVar()
self.labelVar.set("This is the first text: %d" %self.i)
self.label = tk.Label(self.frame, text = self.labelVar.get(), textvariable = self.labelVar)
self.label.pack(side = tk.LEFT)
self.button = tk.Button(self.frame, text = "Update", command = self.updateLabel)
self.button.pack(side = tk.RIGHT)
def updateLabel(self):
self.i += 1
self.labelVar.set("This is new text: %d" %self.i)
root = tk.Tk()
window = Window(root)
root.mainloop()
Important points:
1) A class is used, as it is much easier to pass values around when all Tkinter objects and variables are member variables, accessible from all of your GUI functions.
2) updateLabel does not create a new Label. It simply updates the StringVar() object to hold new text every time you call the function. This is accomplished with the textvariable = self.labelVar keyword when creating my Label widget.
PS: This is done in Python 2.5 so for this code to work for you, change Tkinter to tkinter
EDIT 06/19/2015:
If you want to implement something similar to what I have with your code, without using a class, you'll need to pass around references to your variables.
1) Change start:
Your Labels cpu_choice, status_disp, etc. should be created outside of the function; likely in the same location as question, rock, paper, scissors, etc. You will also pack them outside of the function as well. Same with all the calls to .grid inside of start; you shouldn't need to call pack or grid more than once: right when you create the widget.
The following lines:
playframe.grid(row = 1, column = 0)
historyframe.grid(row = 2, column = 1)
status_disp.pack(fill=X)
Can be done outside of the function as well; you execute these 3 statements under both the if and the elif conditions. This means they aren't really conditional statements; they are done regardless of the validity of the condition.
2) Create a StringVar for both cpu_choice & status_disp & edit the Labels as follows (remember, outside of the function):
cpu_choice_text = StringVar()
cpu_choice_text.set("Set this to whatever is shown at the start of the game")
cpu_choice = Label(historyframe, text = cpu_choice_text.get(), textvariable = cpu_choice_text)
cpu_choice.pack(fill = X)
# And do this same thing for status_disp
3) When you call start, you will now pass it cpu_choice_text & status_disp_text (or whatever they are called). Instead of trying to change the text field of the Label frame, you may now use a set call on the StringVar which is connected to the Label & the Label will automatically update. Example:
def start(cpu_choice_text, status_disp_text):
cpu_choice.set(text = "CPU Choice: {}".format(dict['cpu_choice']))
...
Alternatively, wrap it all in a class and make it much easier for yourself by using self on every Tkinter variable & widget. In this way you won't need to pass variables to your functions, just access member variables directly as I have with self.i, self.labelVar in my example.
Each time you call start you create new labels and use grid to place them in the same spot as the old labels. The best solution is to only create the labels once, but if you insist on creating new labels each time start is called, you need to delete the old labels first.
You can use the destroy() method of a label to destroy it, though for that to work you must keep a global reference of the label.