# Ruby Tk and X/Y coordinates **URL:** \ **Category:** Ruby\ **Created:** [November 30, 2008, 4:37am UTC](https://www.ruby-forum.com/t/ruby-tk-and-x-y-coordinates/154469 "2008-11-30T04:37:28Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![newrubynewbie](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/e79b87/32.png) [@newrubynewbie](https://www.ruby-forum.com/u/newrubynewbie)\ **Post date:** [November 30, 2008, 4:37am UTC](https://www.ruby-forum.com/t/ruby-tk-and-x-y-coordinates/154469/1 "2008-11-30T04:37:28Z")
Hi everyone, I’m totally new to Ruby…I was wondering if anyone could help me out with a little problem I’m having. I want to be able to draw X/Y coordinates on my screen using Tk library. I tried to decipher the docs available online but I guess my skills aren’t where they need to be yet in order to understand them. Any help would be greatly appreciated (a simple example would be awesome). Thanks! ---
**Author:** ![newrubynewbie](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/e79b87/32.png) [@newrubynewbie](https://www.ruby-forum.com/u/newrubynewbie)\ **Post date:** [November 30, 2008, 5:32am UTC](https://www.ruby-forum.com/t/ruby-tk-and-x-y-coordinates/154469/2 "2008-11-30T05:32:28Z")
Johnny J. wrote: > Hi everyone, > > I’m totally new to Ruby…I was wondering if anyone could help me out > with a little problem I’m having. I want to be able to draw X/Y > coordinates on my screen using Tk library. I tried to decipher the docs > available online but I guess my skills aren’t where they need to be yet > in order to understand them. > > Any help would be greatly appreciated (a simple example would be > awesome). Thanks! Dig around in the tk samples dir in the ruby dsitribution… look for ones using tk canvas. It makes life pretty easy, but ask back here if you get stuck. ---
**Author:** ![newrubynewbie](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/e79b87/32.png) [@newrubynewbie](https://www.ruby-forum.com/u/newrubynewbie)\ **Post date:** [December 1, 2008, 3:25am UTC](https://www.ruby-forum.com/t/ruby-tk-and-x-y-coordinates/154469/3 "2008-12-01T03:25:56Z")
From: Johnny J. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Subject: Ruby Tk and X/Y coordinates Date: Sun, 30 Nov 2008 12:32:13 +0900 Message-ID: [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > with a little problem I’m having. I want to be able to draw X/Y > coordinates on my screen using Tk library. I tried to decipher the docs What do you mean with the word “screen” ? If you mean “draw lines or figures on the _application_ window”, a canvas widget can help you. Of course, you can convert screen (desktop) coordinates to window coordinates, and control (move) Ruby/Tk windows by screen coordinates. But, if you mean “draw on the desktop directry”, it is not Ruby/Tk’s business. ---
**Author:** ![newrubynewbie](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/e79b87/32.png) [@newrubynewbie](https://www.ruby-forum.com/u/newrubynewbie)\ **Post date:** [December 1, 2008, 5:51am UTC](https://www.ruby-forum.com/t/ruby-tk-and-x-y-coordinates/154469/4 "2008-12-01T05:51:09Z")
Hidetoshi NAGAI wrote: > From: Johnny J. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > Subject: Ruby Tk and X/Y coordinates > Date: Sun, 30 Nov 2008 12:32:13 +0900 > Message-ID: [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > > > with a little problem I’m having. I want to be able to draw X/Y > > coordinates on my screen using Tk library. I tried to decipher the docs > > What do you mean with the word “screen” ? > If you mean “draw lines or figures on the _application_ window”, > a canvas widget can help you. > Of course, you can convert screen (desktop) coordinates to > window coordinates, and control (move) Ruby/Tk windows by > screen coordinates. > But, if you mean “draw on the desktop directry”, > it is not Ruby/Tk’s business. What I’m trying to do is this: I have an array of x,y coordinates (example=[[0,0], [1,1], [2,2], [3,3], [50,50], etc]…I want my script to create an _application_ window the size of my screen (1024, 768) and draw dots (pixels) at the X/Y coordinates provided by my array. I know that with lines, “to create a line, the one piece of information you’ll need to specify is where the line should be. This is done by using the coordinates of the starting and ending point, expressed as a list of the form x0 y0 x1 y1.” I guess if I set the x1 y1 to x0 y0 then I should just get dots and not lines (I don’t know if that will even work but I’ll test it). Is there an easier way (something that’s specifically created for drawing x/y coordinates)? Thanks ---
**Author:** ![newrubynewbie](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/n/e79b87/32.png) [@newrubynewbie](https://www.ruby-forum.com/u/newrubynewbie)\ **Post date:** [December 1, 2008, 8:52am UTC](https://www.ruby-forum.com/t/ruby-tk-and-x-y-coordinates/154469/5 "2008-12-01T08:52:21Z")
From: Johnny J. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Subject: Re: Ruby Tk and X/Y coordinates Date: Mon, 1 Dec 2008 13:45:46 +0900 Message-ID: [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > What I’m trying to do is this: I have an array of x,y coordinates > (example=[[0,0], [1,1], [2,2], [3,3], [50,50], etc]…I want my script > to create an _application_ window the size of my screen (1024, 768) and > draw dots (pixels) at the X/Y coordinates provided by my array. To draw dots, please use an Oval item or a very short Line item. There are some ways to fill your screen; safe or danger, depend on OS/window-manager or not, and dened on Tcl/Tk version or not. ## One, which is safe and not depend on an environment, is ## root = Tk.root width, height = root.maxsize root.geometry “#{width}x#{height}+0+0” But, it sometimes fails to fill the screen because of a border given by a window-manager. If you use Windows or MacOS X, you can use “Tk.root.state(:zoomed)”. Or, if you use Ruby/Tk with Tcl/Tk8.5 on X Window System and your window-manager support ‘zoomed’, you can use “Tk.root.attributes(:zoomed=\>true)”. ## A danger one is, ## root = Tk.root root.bind(‘1’){exit} # for SAFE; Click the left button, and exit. width = root.winfo\_screenwidth height = root.winfo\_screenheight root.withdraw root.overrideredirect true # NOT controlled by a window-manager. root.deiconify root.geometry “#{width}x#{height}+0+0” This will fill your screen completely. The application is NOT under control of a window-manager. So, if you forget to make the way to exit the application, you may have to shutdown your window system. ## If you use Tcl/Tk8.5, another version of the danger one is, ## root = Tk.root root.bind(‘1’){exit} # for SAFE; Click the left button, and exit. root.attributes(:fullscreen=\>true) > I know that with lines, “to create a line, the one piece of information > you’ll need to specify is where the line should be. This is done by > using the coordinates of the starting and ending point, expressed as a > list of the form x0 y0 x1 y1.” I guess if I set the x1 y1 to x0 y0 then > I should just get dots and not lines (I don’t know if that will even > work but I’ll test it). Is there an easier way (something that’s > specifically created for drawing x/y coordinates)? Thanks If you want dashed lines instead of solid lines, “dash” option may be usefull. ## For example, require ‘tk’ c = TkCanvas.new(:width=\>200, :height=\>400).pack # put dots samples = [ [10,10], [15,15], [20,20], [25,25], [30,30], [35,35], [40,40], [45,45], [50,50], [55,55], [60,60], [65,65], [70,70], [75,75], [80,80], [85,85], [90,90], [95,95], [100,100], [105,105], [110,110], [115,115], [120,120], [125,125], [130,130], [135,135], [140,140], [145,145], [150,150] ] delta = 0.5 samples.each{|x,y| TkcOval.new(c, x, y, x, y, :fill=\>‘red’, :outline=\>‘red’) TkcOval.new(c, x - delta, y + 15 - delta, x + delta, y + 15 + delta, :fill=\>‘red’, :outline=\>‘red’) TkcOval.new(c, x - delta_3, y + 30 - delta_3, x + delta_3, y + 30 + delta_3, :fill=\>‘red’, :outline=\>‘red’) } # very short lines samples.each{|x,y| TkcLine.new(c, x+30, y, x+30+0.5, y+0.5, :fill=\>‘black’, :width=\>1) } # dash line coords = [[10, 80], [150, 220]] TkcLine.new(c, coords, :fill=\>‘red’, :width=\>1, :dash=\>‘.’) coords.map!{|x,y| [x, y+15]} TkcLine.new(c, coords, :fill=\>‘red’, :width=\>3, :dash=\>‘.’) coords.map!{|x,y| [x, y+15]} TkcLine.new(c, coords, :fill=\>‘red’, :width=\>1, :dash=\>‘-’) coords.map!{|x,y| [x, y+15]} TkcLine.new(c, coords, :fill=\>‘red’, :width=\>3, :dash=\>‘-’) coords.map!{|x,y| [x, y+15]} TkcLine.new(c, coords, :fill=\>‘red’, :width=\>1, :dash=\>‘-.’) coords.map!{|x,y| [x, y+15]} TkcLine.new(c, coords, :fill=\>‘red’, :width=\>3, :dash=\>‘-.’) coords.map!{|x,y| [x, y+15]} TkcLine.new(c, coords, :fill=\>‘red’, :width=\>1, :dash=\>[2,2]) coords.map!{|x,y| [x, y+15]} TkcLine.new(c, coords, :fill=\>‘red’, :width=\>3, :dash=\>[2,2]) coords.map!{|x,y| [x, y+15]} TkcLine.new(c, coords, :fill=\>‘red’, :width=\>1, :dash=\>[6,2,2,2]) coords.map!{|x,y| [x, y+15]} TkcLine.new(c, coords, :fill=\>‘red’, :width=\>3, :dash=\>[6,2,2,2]) coords.map!{|x,y| [x, y+15]} TkcLine.new(c, coords, :fill=\>‘red’, :width=\>3, :dash=\>[12,4,4,4]) Tk.mainloop