GUIs - A Modest Proposal
in [Python]
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From: Stephen Hansen on 13 Jun 2010 02:35 On 6/12/10 8:22 PM, Gregory Ewing wrote: > Terry Reedy wrote: > >> Would it be possible to write a program that converts a module that >> uses ctypes to interface to a dll to a corresponding C extension >> program that would compile to a drop in replacement extension module? > > Probably, but I don't see how that could be done automatically > in a way that ensured the result would be any safer than the > original ctypes-using version. If you preserve the semantics of > the Python code, you also preserve any bugs it might have. I dunno. This is exactly what Cython does. I have exactly one extension module in Cython that uses it, and so very limited experience-- but it seems very solid and very safe, from my admittedly limited attempts at breaking it. True, Cython != Python. But its close enough that Python programmers can do it without knowing the pain of C, just following a certain limited Python subset. Its very doable, very accessible, and *seems* to address this very issue. -- Stephen Hansen ... Also: Ixokai ... Mail: me+list/python (AT) ixokai (DOT) io ... Blog: http://meh.ixokai.io/
From: Jeremy Sanders on 13 Jun 2010 05:01 lkcl wrote: > * in neither gtk nor qt does there exist an "auto-layout" widget > that's equivalent to putting some <span /> DOM objects into a <div />, > to "flow" widgets that wrap around. yes, you can put words into a > Label and get them to flow, but not _widgets_. I'm pretty sure in PyQt4 that you can derive your own layout class from QLayout to get what you want. No C++ is required. You can easily extend PyQt without using C++. There is even an example in the PyQt examples which does something similar to what you want: see examples/layouts/flowlayout.py Personally I find the Qt layout to be much better than anything provided by CSS and HTML. Personally I'd rather be writing complex C++ templates that those, though it does give you a feeling of achievement when you get what you want with CSS. Jeremy -- Jeremy Sanders http://www.jeremysanders.net/
From: lkcl on 13 Jun 2010 07:20 On Jun 13, 3:34 am, Gregory Ewing <greg.ew...(a)canterbury.ac.nz> wrote: > lkcl wrote: > > * in neither gtk nor qt does there exist an "auto-layout" widget > > that's equivalent to putting some <span /> DOM objects into a <div />, > > to "flow" widgets that wrap around. > > You essentially seem to be complaining here that pqyqt and > pygtk are not HTML. no, i'm not complaining - i'm pointing out that in my meandering experiences to pick suitable technology, i found, very simply, that both pyqt and pygtk didn't cut it. that's not a "complaint". so i'm stating/implying that from the experience that i had with both toolkits, pyqt and pygtk were not as easy to create layouts or widgets with (but caveat: jeremy kindly points out that in pyqt there is examples/layouts/flowlayout.py) another way to put that: i'm stating that, in my search for suitable technology to implement W3C-standards-like behaviour, such that i could map an existing widget set API on top of it, i found both pygtk and pyqt4's "bang per buck" as far as both extensibility and existing functionality was concerned to be below an acceptable threshold *for me*. statement of "personal experience". not "complaint". > They have their own auto-layout mechanisms > that do what they're designed to do well enough -- they just > happen to be based on a different model from HTML. one which turns out to be sufficiently different from HTML as to make it beyond my time and patience to implement one in terms of the other. again - that's not a "complaint", just a statement that i prefer to leverage technologies where the "bang per buck" or better "bang per line-of-code" is way above average. > I'm far from convinced that HTML and CSS are the One True Way > to design GUIs these days, if you have "HTML the fileformat" and "CSS the fileformat" in mind when saying that, i can tell you right now that they're not. fortunately, with the W3C DOM functions exposing properties and style attributes, it's possible to manipulate the exact same attributes that CSS and HTML "files" provide access to, using a declarative programming style. so with pyjamas you get the best of both worlds. (and i've found that the combination of the advanced features of python, and declarative DOM manipulation, is _definitely_ worthwhile exploring, and i definitely find it to be far more powerful than pyqt4 or pygtk programming). it's the exact same thing for SVG image file-format. i'm _definitely_ not convinced that "SVG the image fileformat" is The One True Way to design images - but i'm equally definitely convinced of the power of SVG manipulation libraries which allow for the creation SVG images using declarative programming. but, all that having been said, and returning to "HTML and CSS (the fileformats)", there's a lot to be said for convincing people who are stuck in those worlds of the benefits and freedom of declarative programming... _without_ having to get involved directly in javascript. > that web apps are about to take over > the world, etc. There is still a place for GUI toolkits that > are not based on the DOM, that there definitely are. > or whatever the W3C technology of the month is. :) don't underestimate how much time and money is going into the W3C standards! and remember, someone's got to implement them, so the actual proof of the pudding is not what the W3C thinks but whether the technology ends up actually in the hands of users and is successful _for users_. l.
From: lkcl on 13 Jun 2010 07:29 On Jun 13, 9:01 am, Jeremy Sanders <jeremy +complangpyt...(a)jeremysanders.net> wrote: > lkcl wrote: > > * in neither gtk nor qt does there exist an "auto-layout" widget > > that's equivalent to putting some <span /> DOM objects into a <div />, > > to "flow" widgets that wrap around. yes, you can put words into a > > Label and get them to flow, but not _widgets_. > > I'm pretty sure in PyQt4 that you can derive your own layout class from > QLayout to get what you want. No C++ is required. You can easily extend PyQt > without using C++. really? drat. i could have done with knowing that at the time. hmmm, perhaps i will return to the pyqt4 port after all. > There is even an example in the PyQt examples which does something similar > to what you want: see examples/layouts/flowlayout.py excellent! that actually makes it worthwhile carrying on. the only other thing that needs solving is that RichText is forced to have its width and height set. but it mayyy be possible to create an appropriate QLayout derivative: i'll have to see. > Personally I find the Qt layout to be much better than anything provided by > CSS and HTML. Personally I'd rather be writing complex C++ templates that > those, though it does give you a feeling of achievement when you get what > you want with CSS. i didn't point this out at the time (and have done so to graham's post, but it's worth reiterating briefly here): remember that you're not _entirely_ stuck with "CSS the file-format" - you _can_ do declarative DOM manipulation (from python): self.element.style.backgroundColor = "#ffcc00" that's python _not_ javascript :) so, now you can create **kwargs jobbies, you can store properties in xml fileformats, read them and then "apply" them using **kwargs to the stylesheets; you can create functions which set multiple CSS properties at once, based on some calculations and so on. so, yah - when you're "stuck" with "just CSS the fileformat", it's a complete dog. joy. lovely. you can set the width and the background. wow, big deal. but when you start combining it with python, you've opened up a completely new dimension. it's in fact how the entire pyjamas UI widget set is created, by doing nothing more than direct manipulation of bits of DOM and direct manipulation of the style properties. really really simple. l.
From: Stephen Hansen on 13 Jun 2010 10:34
On 6/13/10 4:29 AM, lkcl wrote: > it's in fact how the entire pyjamas UI widget set is created, by > doing nothing more than direct manipulation of bits of DOM and direct > manipulation of the style properties. really really simple. Did you just call DOM manipulation simple with a straight face? I don't think I've ever seen that before. HTML+CSS have some very strong advantages. Simplicity is not one of them. Precision web design these days is a dark art. (Go center an image vertically and horizontally in an arbitrary sized field!) -- Stephen Hansen ... Also: Ixokai ... Mail: me+list/python (AT) ixokai (DOT) io ... Blog: http://meh.ixokai.io/ |