From: Alex Fenton <alex@...>
Date: 2008-04-01T06:10:04+09:00
Subject: Re: Displaying gruff graphs

Victor Reyes wrote:

> I finally got this working with wx by hard-coding the file path.

That other first error looks like an ImageMagick problem. Sorry I can't 
help with that as I'm too lazy to install it; I just used wxRuby's own 
image file writing features to test it out quickly.

> The graphs
> (pie) is displayed, but now I have a small glitch, of course.
> The frame is a about 1/4 of what it needs to be, and so I have to resize it
> with the mouse.
> Perhaps I need to make the frame where the graph is displayed a bit larger.
> Is there anyway to make the size of the frame "dynamic" based on the size of
> the image to be displayed?

You can either constrain the frame to be a particular size, and prevent 
it being resized, or dynamically resize the graph image as the frame is 
resized by the user's use of the mouse.

For the former, when you call super in the GruffFrame constructor, add 
the argument :style => Wx::DEFAULT_FRAME_STYLE ^ Wx::RESIZE_BORDER

(i.e. use the default frame style, minus the mouse-draggable resize 
handle in the corner)

Then in the GruffFrame#initialize method, set the Frame's client_size to 
the size you want the image, e.g.

self.client_size = [480, 320]

(The "client size" is the space within the Frame that is available for 
drawing on - its total pixel size minus the window borders, title bar 
etc. This way of setting the frame size will given consistent results 
across Linux, Windows and OS X)

If you want the latter, a resizeable frame, on each refresh, tell Gruff 
  what size of PNG you want. According to the docs, you can pass the 
Gruff Graph constructor a size as a string. So call new like this:

graph = Gruff::Lines.new("#{client_size.width}x#{client_size.height}")

If you go down this route, you'll probably also want to refresh the 
graph if the Frame is resized; use evt_size in the frame constructor for 
this:

evt_size { | evt | refresh; evt.skip }

> In the mean time I will look in the wx documentation.

I expect you've found http://wxruby.rubyforge.org/doc/

If you've got further questions about wxRuby, there's a friendly mailing 
list which is a better place than c.l.r. for specifically wxRuby 
questions: http://rubyforge.org/mail/?group_id=35

alex