# Newbie question Canvas or frame **URL:** \ **Category:** Ruby\ **Created:** [October 10, 2006, 12:19pm UTC](https://www.ruby-forum.com/t/newbie-question-canvas-or-frame/71624 "2006-10-10T12:19:25Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![merrua](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/a698b9/32.png) [@merrua](https://www.ruby-forum.com/u/merrua)\ **Post date:** [October 10, 2006, 12:19pm UTC](https://www.ruby-forum.com/t/newbie-question-canvas-or-frame/71624/1 "2006-10-10T12:19:25Z")
In ruby-tk Do you need a canvas to show a picture or is it ok to show a picture on a frame? When should you use a canvas? ---
**Author:** ![merrua](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/a698b9/32.png) [@merrua](https://www.ruby-forum.com/u/merrua)\ **Post date:** [October 10, 2006, 12:46pm UTC](https://www.ruby-forum.com/t/newbie-question-canvas-or-frame/71624/2 "2006-10-10T12:46:39Z")
Mer G. wrote: > In ruby-tk > Do you need a canvas to show a picture or is it ok to > show a picture on a frame? > When should you use a canvas? Ok. canvas is needed to display picture. but i still would like to hear peoples comments about canvases and frames to understand them better. ---
**Author:** ![merrua](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/a698b9/32.png) [@merrua](https://www.ruby-forum.com/u/merrua)\ **Post date:** [October 10, 2006, 3:58pm UTC](https://www.ruby-forum.com/t/newbie-question-canvas-or-frame/71624/3 "2006-10-10T15:58:58Z")
From: Mer G. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Subject: Newbie question Canvas or frame Date: Tue, 10 Oct 2006 19:19:28 +0900 Message-ID: [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > In ruby-tk > Do you need a canvas to show a picture or is it ok to > show a picture on a frame? If you want to show a picture only, you don’t need a canvas widget. Please create a TkPhotoImage object and assign it to `image' option of a TkLabel object (or a widget which has `image’ option). Current standard Tcl/Tk suuports only GIF and PPM/PGM formats. If you want to treat other formats (JPEG, BMP, and so on), you need to use `TkImg’ extension (ActiveTcl package already includes it). Current Ruby/Tk supports TkImg extension. > When should you use a canvas? There are many cases. - When needs a drawing field (and save it by Postscrpt format). - When want to handle widgets or canvas items (Line, Oval, and so on) by coordinates. Please see the example “Ruby/Tk widget demo” which is included in Ruby source archive. - When want to assign bindings to some parts of a picture (e.g. a tree picture which has clickable branches). - When want to create a scrollable frame. Please see the example “ext/tk/sample/scrollframe.rb” on Ruby source tree. # On Ruby/TkORCA, a canvas widget takes place of a pseudo window # manager for slave Ruby/Tk applications. ---
**Author:** ![merrua](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/a698b9/32.png) [@merrua](https://www.ruby-forum.com/u/merrua)\ **Post date:** [October 10, 2006, 4:20pm UTC](https://www.ruby-forum.com/t/newbie-question-canvas-or-frame/71624/4 "2006-10-10T16:20:37Z")
Hidetoshi NAGAI wrote: > If you want to show a picture only, you don’t need a canvas widget. > Please create a TkPhotoImage object and assign it to `image' option of a TkLabel object (or a widget which has`image’ option). Ah. Im using TkPhotoImage with canvas and a frame. Is this ok ? And the `TkImg’ extension, do I add that with require “TKImg”. I have active tcl on the computer. ---
**Author:** ![merrua](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/a698b9/32.png) [@merrua](https://www.ruby-forum.com/u/merrua)\ **Post date:** [October 13, 2006, 3:36pm UTC](https://www.ruby-forum.com/t/newbie-question-canvas-or-frame/71624/5 "2006-10-13T15:36:18Z")
Thank You! ---
**Author:** ![merrua](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/m/a698b9/32.png) [@merrua](https://www.ruby-forum.com/u/merrua)\ **Post date:** [October 10, 2006, 6:13pm UTC](https://www.ruby-forum.com/t/newbie-question-canvas-or-frame/71624/6 "2006-10-10T18:13:56Z")
From: Mer G. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) Subject: Re: Newbie question Canvas or frame Date: Tue, 10 Oct 2006 23:20:40 +0900 Message-ID: [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) > Ah. Im using TkPhotoImage with canvas and a frame. Is this ok ? That is OK, if that is what you want. 🙂 > And the `TkImg’ extension, do I add that with require “TKImg”. > I have active tcl on the computer. Please use “require ‘tkextlib/tkimg’”. If your Ruby/Tk loads libraries of ActiveTcl, that will work.