Midway through making my program I realise there are some discrepancies between the height / width properties of objects.
For example in my document here, the main green frame has a width of 640 whereas the buttons are only a size of 3 yet they appear so much larger. How exactly is width and height calculated (is it always pixels)
Image
The width and height attributes don't always refer to pixels. For some widgets, the width and height is in characters. For example, `Label(root, text="Hello", width=10) will make a widget that is wide enough to hold 10 average sized characters in the default font.
Just about any widget that has text will measure width and height in characters (Text, Label, Button, etc). Widgets that do not have text as part of their normal appearance (Frame, Canvas, etc) are measured in pixels.
For some, the value of width and height depends on other options. For example, in a Button or Label, if the widget sets the image attribute then the values will be in pixels, and if the image attribute is not set then the values will be in characters.
The documentation for each widget will say what the width and height represents.
Ya, Height and Width is measured in pixels
Related
I put initial screensize for turtle, but it open with the same standard size and scrollbars. Do not open with total size. Have any way to start window with total size (without scollbars)?
Thank you!
import turtle as t
largura = 1200
altura = 800
t.screensize(canvwidth=largura, canvheight=altura, bg='lightgrey')
You can set the window's size using the setup() method or function. Don't use screensize() for this purpose. For details see this answer.
Any window 420 x 320, or larger, shouldn't get scrollbars by default. For details see this answer.
setup() function can be used.code snippet
turtle.setup(width=_CFG["width"], height=_CFG["height"], startx=_CFG["leftright"], starty=_CFG["topbottom"])
Set the size and position of the main window. Default values of arguments are stored in the configuration dictionary and can be changed via a turtle.cfg file.
Parameters
width – if an integer, a size in pixels, if a float, a fraction of the screen; default is 50% of screen
height – if an integer, the height in pixels, if a float, a fraction of the screen; default is 75% of screen
startx – if positive, starting position in pixels from the left edge of the screen, if negative from the right edge, if None, center window horizontally
starty – if positive, starting position in pixels from the top edge of the screen, if negative from the bottom edge, if None, center window vertically
screen.setup (width=200, height=200, startx=0, starty=0)
# sets window to 200x200 pixels, in upper left of screen
screen.setup(width=.75, height=0.5, startx=None, starty=None)
# sets window to 75% of screen by 50% of screen and centers
I cannot seem to get the scroll on this text to work. The text will scroll to a certain extent, but then not appear afterwards. I believe that the height of the text widget is not what I want. For instance, the image below shows only about a half of what the actual result is for 遺伝子 (which I can find out by attempting to drag from a piece of text in the middle of the frame to the bottom). The width also is not the same size of the frame I would like it to be: the number 23 was just something that appeared to work.
If I do
txt = tk.Text(self.SEARCH_RESULTS_TEXT_FRAME,width=self.SEARCH_RESULTS_FRAME_WIDTH,height=20,background='#d9d9d9',relief=RIDGE)
... the width becomes much too large. I would have thought that it would only take up the size of the frame, which is 240.
Note the SEARCH_RESULTS_TEXT_FRAME is the frame in red.
Relevant code:
#search text frame
self.SEARCH_RESULTS_FRAME_HEIGHT = 240 #240
self.SEARCH_RESULTS_FRAME_WIDTH = self.TITLE_FRAME_WIDTH - 23
self.SEARCH_RESULTS_TEXT_FRAME = Frame(self.SEARCH_RESULTS_FRAME,height=self.SEARCH_RESULTS_FRAME_HEIGHT,width=self.SEARCH_RESULTS_FRAME_WIDTH)
self.SEARCH_RESULTS_TEXT_FRAME.place(x=10,y=10,anchor = NW)
self.SEARCH_RESULTS_TEXT_FRAME.config(background ="#adadad")
def print_dict_to_frame(self,results_list):
txt = tk.Text(self.SEARCH_RESULTS_TEXT_FRAME,width=34,height=20,background='#d9d9d9',relief=RIDGE)
txt.place(x=0,y=0)
txt.tag_configure('header',justify = 'center',font=("Meiryo",12,'bold'))
txt.tag_configure('entry',font=('Meiryo',8))
for r_list in results_list:
header = r_list[0]
entry = r_list[1]
txt.insert(tk.END, "{}\n".format(header),'header')
for single_result in entry:
txt.insert(tk.END,single_result+"\n",'entry')
txt.configure(state=DISABLED)
How can I get the text widget to only take up the width of the frame and the height of the frame, allowing for scrolling?
If I do txt = tk.Text(self.SEARCH_RESULTS_TEXT_FRAME,width=self.SEARCH_RESULTS_FRAME_WIDTH,height=20,background='#d9d9d9',relief=RIDGE) ... the width becomes much too large. I would have thought that it would only take up the size of the frame, which is 240.
The width option specifies a width in the number of characters, not pixels. If you use the value 240, the width will be 240 multiplied times the width of an average character in the font you are using.
How can I get the text widget to only take up the width of the frame and the height of the frame, allowing for scrolling?
Give the text widget a width and height of 1, and then let the geometry manager (pack, place, or grid) be responsible for stretching it to fit the frame.
Since you're using place, you can use the relwidth and relheight options to make it the full size of the frame:
txt.place(x=0,y=0, anchor="nw", relwidth=1.0, relheight=1.0)
Personally, I recommend using pack or grid in almost all cases. It's much easier to create a responsive UI with them than it is with place.
I'm new to tkinter, trying to create a square botton but I can't.
from tkinter import *
root = Tk()
button1 = Button(text = "Cuadrado", height = 10, width = 10).pack()
root.mainloop()
The widht and the height are the same valor, but the button that create with the code is a rectangle.
Why does it happen?
The width and height of a button that has text but no image are in the number of characters (ie: height=10 means it should be 10 characters tall).
The average character in your font is almost certainly not a square -- fonts are typically taller than they are wide. Thus, 10 characters wide will likely be fewer pixels than 10 characters tall.
The height of the characters is about 2.3 times greater than the width. So, to draw a square button, you can use proportions like this:
Button(width=2, height=1)
Button(width=9, height=4)
Button(width=19, height=8)
Button(width=37, height=16)
I was looking through the tkinter widgets at https://effbot.org/tkinterbook/canvas.htm and noticed that the width configure option for the canvas defaults to '10c'
width=
Canvas width. Default value is ‘10c’. (width/Width)
What does that mean? What effect does that have on how its width is handled by pack and grid geometry?
Question: Canvas default width = '10c', What does that mean?
Reference:
width
Specifies a desired window width that the Canvas widget should request from its geometry manager. The value may be specified in any of the forms described in the COORDINATES section below.
COORDINATES
Coordinates and distances are specified in screen units, which are floating-point numbers optionally followed by one of several letters m|c|p.
If no letter is supplied then the distance is in pixels.
If it is c then the distance is in centimeters;
I apologize in advance if my question is a duplicate however I have not found an answer to this question.
I'm learning Tkinter and I'm struggling with understanding the relation between a label's font type, it's size and it's width and the length of the string in it.
Specifically, what my problem is:
I have created a widget: a 800x640 canvas on which I want to place other
widgets.
On this canvas I want to place a label with some text which has the following
attributes: font: Helvetica, font size: 20, text = "main application". I want
to place this label widget at the very most top left corner of the
widget(meaning at point 0,0 with respect to the canvas). I want the label to
be 200 in width meaning it's background to take almost 1/3 of the canvas's
size(after I manage to do this I plan to add 2 more labels as well). I guess
the height of the label is determined by the font size in this case 20. I
placed the label at coordinate y=20 and this coordinate seems to be ok.
I did some googling and found out that the width parameter of the label widget is not the actual width but something related to the font and size of the label's text: something like if I understood correctly: if the width is 6 than the label will be wide enough to contain 6 characters of, in my case verdana size 20. But I was not able to figure out what width and what x coordinate I should give my label so it starts at the x point of the canvas. Here is the code that I wrote:
from tkinter import *
from tkinter.ttk import *
from tkinter import messagebox
from tkinter import Menu
# Define the application class where we will implement our widgets
class Application(Frame):
def __init__(self, master):
super(Application, self).__init__(master)
# CANVAS COLOUR DEFAULTS TO THE COLOUR OF THE WORKING WINDOW
canvas = Canvas(master, width=800, height = 640, bg="gray") # IF YOU DO .PACK() HERE IT WILL RETURN NONE AND THEN YOU WILL HAVE PROBLEMS BECAUSE .PACK() RETURNS A 'NONE' TYPE OBJECT
canvas.place(relx=0.5, rely=0.5, anchor=CENTER)
# The 'menu' of the application. The selection labels
main_application_label = Label(master, text="main_application", font=("Helvetica", 20))
main_application_window = canvas.create_window(103,20, window=main_application_label)
main_application = Tk()
main_application.title("main_application")
app = Application(main_application)
app_width = 800
app_height = 640
screen_width = main_application.winfo_screenwidth()
screen_height = main_application.winfo_screenheight()
x_coord = (screen_width/2) - (app_width/2)
y_coord = (screen_height/2) - (app_height/2)
main_application.geometry("%dx%d+%d+%d" % (app_width, app_height, x_coord, y_coord))
main_application.mainloop()
I have managed to somehow get the label at around point 0,0(by giving more values till I got it right) but the actual width of the label is not 200 pixels(~1/3 of the canvas). Please help me understand what values to the width parameter I should give so that my label's background is 1/3 of the canvas's size and if possible explain the relation between character font and width parameter so I can do that for any widgets regardless of their text's length. Thank you for reading my post!
Edit: What I wanted to do was to place 3 widgets(labels in this case but it doesn't matter) on the canvas. I did not understand what the 'anchor' option does and that was confusing me because I was expecting the center of the widget to be placed at the given coordinates all times but as I was changing anchor the placement of the center of the widget was changing and that was confusing me. It's all clear now thanks to #Bryan Oakley. Thanks.
If you want the upper left corner of the text to be at (0,0), you don't have to adjust the coordinates based on the width. You can use the anchor option when creating the canvas object:
main_application_window = canvas.create_window(0, 0, anchor="nw",
window=main_application_label)
If you really need to compute the actual size of the string, you can create a Font object and then use the measure method to find the actual width of a string in the given font.
from tkinter.font import Font
font = Font(family="Helvetica", size=20)
string_width = font.measure("main_application")
string_height = font.metrics("linespace")
This gives you the size of the rendered string. If you're using a label widget you'll also need to take into account the amount of padding and borders that the widget uses.
When you create items on a canvas, you can specify the width and height. For example, this makes the widget 200 pixels wide:
main_application_window = canvas.create_window(0, 0, anchor="nw", width=200,
window=main_application_label, width=400)