| Re: IDLgrLegend geometry [message #23879] |
Mon, 26 February 2001 21:33  |
davidf
Messages: 2866
Registered: September 1996
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Senior Member |
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Mark Hadfield (m.hadfield@niwa.cri.nz) writes:
> In fact on my system legends do get resized as the size of the destination
> device changes! I wonder why they don't on yours, George. What version are
> you using? Do you have a line that looks like this in the CreateGlyphs
> method in idlgrlegend__define.pro?
>
> (*self.pTexts)[index] = OBJ_NEW('IDLgrText', $
> FONT = self.oFont, $
> COLOR = (*self.pText_Color), $
> STRINGS = (*self.pItem_Name)[index],$
> RECOMPUTE_DIMENSIONS = 2)
Speaking of the RECOMPUTE_DIMENSIONS keyword, I realized
in the last object class I taught that my understanding
of what this keyword does was exactly the opposite of
what it *actually* does. (I discovered this when some
overzealous student actually typed the commands I said
to type and discovered that the program did the opposite
of what I said it would do. I *hate* students like this.)
This whole question suddenly rang some bells with me,
and I spent some time this evening going through the
documentation very s-l-o-w-l-y, trying to understand
it.
Text characters are sized according to a text "box",
whose width and height are given in the "data" units
of your arbitrary coordinate system. (See the
CHAR_DIMENSIONS keyword.) What RECOMPUTE_DIMENSIONS
can do is tell you when to recompute the size of that
text box. For example, if you change the data range,
you will probably want to recompute your text box.
But, and here is the point I was confused about, if
you are just re-sizing the graphic there is no need
to recompute the text box, since the data range
doesn't change at all. In fact, in resizing windows
you explicitly do NOT want to recompute dimensions.
You can see this by downloading the Simple_Surface
program from my web page:
http://www.dfanning.com/programs/simple_surface.pro
In this program, I have RECOMPUTE_DIMENSIONS set to
2. Notice when you resize the window that the text
sizes remain the same size. (I still doesn't understand
why this should be so, and I am looking for enlightenment
on this point.) But if you change all the RECOMPUTE_DIMENSIONS=2
to RECOMPUTE_DIMENSIONS=0 you will find that the text
is size proportionally to the axes, the data, etc. This
is the behaviour I want.
So, (sorry for the stream of consciousness here, it is
late and I am very tired), why, if I don't change the
data coordinate system at all, simply resize the window
and then recompute the text box dimensions, does the
text *always* stay the same size? Is it because a 14
point font is a particular size regardless of the size
of the output window?
Mark!? Are you back from lunch yet? :-)
Cheers,
David
P.S. I think IDLgrLegend works correctly because the
author is calculating new text box sizes for each
draw. Thus, he *should* recompute the dimensions
before every draw. But this seems VERY low-level
to me. Is this really necessary?
--
David Fanning, Ph.D.
Fanning Software Consulting
Phone: 970-221-0438 E-Mail: davidf@dfanning.com
Coyote's Guide to IDL Programming: http://www.dfanning.com/
Toll-Free IDL Book Orders: 1-888-461-0155
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| Re: IDLgrLegend geometry [message #23880 is a reply to message #23879] |
Mon, 26 February 2001 20:26  |
George Constantinides
Messages: 16
Registered: July 2000
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Junior Member |
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Mark Hadfield wrote:
> "David Fanning" <davidf@dfanning.com> wrote in message
> news:MPG.150498b583111c38989d69@news.frii.com...
>> George Constantinides (gconstantinides@mhl.nsw.gov.au) writes:
>>
>>> I was resizing an IDLgrWindow object and noticed that objects such as
>>> IDLgrAxis, IDLgrPlot,IDLgrText resized correctly to fit the new
>>> dimensions, but IDLgrLegend did not.
>>> [...]
>>
>> Humm. It's pretty clear that the author of IDLgrLegend
>> was *trying* to solve this problem in the ComputeDimensions
>> method. Have you tried using this when you resize or change
>> to another destination device? It looks to me like this
>> would solve all your problems, although I confess I've
>> never used IDLgrLegend.
I tried calling ComputeDimensions explicitly but I was not making any sense
of the result so I gave up on this approach.
>
>
> From my reading of the IDLgrLegend code in version 5.4, ComputeDimensions is
> called every time the legend is re-drawn, so there should be no need to call
> it manually. ComputeDimensions recalculates the dimensions of the legend's
> atoms based on the character size of the legend text, and since the text
> objects are created with RECOMPUTE_DIMENSIONS = 2, the legend should be
> resized every time it is drawn.
>
> In fact on my system legends do get resized as the size of the destination
> device changes! I wonder why they don't on yours, George. What version are
> you using? Do you have a line that looks like this in the CreateGlyphs
> method in idlgrlegend__define.pro?
>
> (*self.pTexts)[index] = OBJ_NEW('IDLgrText', $
> FONT = self.oFont, $
> COLOR = (*self.pText_Color), $
> STRINGS = (*self.pItem_Name)[index],$
> RECOMPUTE_DIMENSIONS = 2)
>
> If you want to debug this you could put a break in ComputeDimensions and see
> what's happening. (Warning: you may be surprised how often a model's Draw
> method is called.)
>
I am using 5.4 on NT.
Now that I know it works for someone I'll go and have another look.
George Constantinides
Manly Hydraulics Laboratory
URL http://www.mhl.nsw.gov.au
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| Re: IDLgrLegend geometry [message #23887 is a reply to message #23880] |
Mon, 26 February 2001 16:17 |
Mark Hadfield
Messages: 783
Registered: May 1995
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Senior Member |
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"David Fanning" <davidf@dfanning.com> wrote in message
news:MPG.150498b583111c38989d69@news.frii.com...
> George Constantinides (gconstantinides@mhl.nsw.gov.au) writes:
>
>> I was resizing an IDLgrWindow object and noticed that objects such as
>> IDLgrAxis, IDLgrPlot,IDLgrText resized correctly to fit the new
>> dimensions, but IDLgrLegend did not.
>> [...]
>
> Humm. It's pretty clear that the author of IDLgrLegend
> was *trying* to solve this problem in the ComputeDimensions
> method. Have you tried using this when you resize or change
> to another destination device? It looks to me like this
> would solve all your problems, although I confess I've
> never used IDLgrLegend.
From my reading of the IDLgrLegend code in version 5.4, ComputeDimensions is
called every time the legend is re-drawn, so there should be no need to call
it manually. ComputeDimensions recalculates the dimensions of the legend's
atoms based on the character size of the legend text, and since the text
objects are created with RECOMPUTE_DIMENSIONS = 2, the legend should be
resized every time it is drawn.
In fact on my system legends do get resized as the size of the destination
device changes! I wonder why they don't on yours, George. What version are
you using? Do you have a line that looks like this in the CreateGlyphs
method in idlgrlegend__define.pro?
(*self.pTexts)[index] = OBJ_NEW('IDLgrText', $
FONT = self.oFont, $
COLOR = (*self.pText_Color), $
STRINGS = (*self.pItem_Name)[index],$
RECOMPUTE_DIMENSIONS = 2)
If you want to debug this you could put a break in ComputeDimensions and see
what's happening. (Warning: you may be surprised how often a model's Draw
method is called.)
---
Mark Hadfield
m.hadfield@niwa.cri.nz http://katipo.niwa.cri.nz/~hadfield
National Institute for Water and Atmospheric Research
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| Re: IDLgrLegend geometry [message #23969 is a reply to message #23879] |
Tue, 27 February 2001 12:29 |
Mark Hadfield
Messages: 783
Registered: May 1995
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Senior Member |
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"David Fanning" <davidf@dfanning.com> wrote in message
news:MPG.1504ea1077595651989d6a@news.frii.com...
> In this program, I have RECOMPUTE_DIMENSIONS set to
> 2. Notice when you resize the window that the text
> sizes remain the same size. (I still doesn't understand
> why this should be so, and I am looking for enlightenment
> on this point.) But if you change all the RECOMPUTE_DIMENSIONS=2
> to RECOMPUTE_DIMENSIONS=0 you will find that the text
> is size proportionally to the axes, the data, etc. This
> is the behaviour I want.
Oops. I am guilty (again) of not thinking and observing carefully enough
before I post. RECOMPUTE_DIMENSIONS does work exactly as you say and I think
that is the opposite of what I implied in my earlier message. However,
unlike you, David, I prefer my text to stay the same size when I resize my
windows so I tend to use RECOMPUTE_DIMENSIONS = 2.
BTW the legend test program I referred to earlier is mgh_example_legend, of
which there is a copy at
http://katipo.niwa.cri.nz/~hadfield/gust/software/idl/
but don't bothering downloading it right now because somebody told me it's
broken. I will fix it shortly.
Anyway, when I run mgh_example_legend (fixed version) and resize the window,
all the symbols (including the ones in the legend) scale with the window and
all the text (including the legend labels) keeps a constant size. This
behaviour seems reasonable to me.
Looking back at your original post, George, I am not sure what you mean by
"resize correctly to fit the new dimensions". Do you want the legend text to
scale with the window size? Perhaps you should try changing the IDLgrLegend
code so that text objects are created with RECOMPUTE_DIMENSIONS = 0.
This business of being an IDL guru is very hard, what with making yourself
look silly all the time and having people tell you your code is broken. I
think I'll take a breather. How do you manage it, David?
---
Mark Hadfield
m.hadfield@niwa.cri.nz http://katipo.niwa.cri.nz/~hadfield
National Institute for Water and Atmospheric Research
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| Re: IDLgrLegend geometry [message #23997 is a reply to message #23969] |
Thu, 01 March 2001 12:01 |
Pavel A. Romashkin
Messages: 531
Registered: November 2000
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Senior Member |
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Mark Hadfield wrote:
> This business of being an IDL guru is very hard, what with making yourself
> look silly all the time and having people tell you your code is broken. I
> think I'll take a breather. How do you manage it, David?
You can always jump to the lurkers category :-)
P
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