----- Original Message ----
From: Mathias Gaunard <mathias.gaunard@ens-lyon.org> To: boost@lists.boost.org Sent: Mon, June 20, 2011 12:09:50 PM Subject: Re: [boost] [gui] Help with a little experiment.
On 18/06/2011 16:55, Artyom Beilis wrote:
Making a GUI library is not about providing nice syntactic sugar for building layout.
Syntactic sugar is the last thing that should interest you.
Having a short and concise declarative definition of your GUI has several advantages. It's easier to validate it, it allows to avoid bugs, and you can really materialize the intent of what you want instead of coding its logic directly.
Moreover, writing GUIs is very tedious and uninteresting. It would be nice if it were possible to automate more things.
Few points. If you want an easy and fast declare GUI there are many RAD tools like QtCreator or Glade that do this job well. On the other hand. When I was programming some GUI tools the **easiest** part was to write a code that makes the layout and connects widgets... The hard part was to write the actions that should be done behind the widgets. Today when I write production code I think about users who are going to maintain it. And readability and clearness is very big concern. See: http://developer.qt.nokia.com/wiki/API_Design_Principles There are 6 primary points: * Be minimal * Be complete * Have clear and simple semantics * Be intuitive * Be easy to memorize * Lead to readable code Especially this one: An API is intuitive if a semi-experienced user gets away without reading the documentation, and if a programmer who doesn’t know the API can understand code written using it. IMHO The proposed API does not helps with all this and makes things very obscure for a programmer that is not fully familiar with the toolkit. If I show this code to average C++ programmer the vast majority of them would not know what happens there... The fact that you and 1 percentile of C++ programmers (that write Boost Libraries) understand the proposed code does not mean it is understandable to other. Consider: This
auto gui_definition = Window(title="Hello, world!") << VBox(expand=true) << HBox(expand=true) << Label(text="Name:") && Entry[SLOT(onEntryChanged)]) << End(HBox); << Button(text="hello")[SLOT(onButtonClick)]; << End(VBox) << End(Window);
Or this? class MyWindow : public Window { MyWindow { setTitle(tr("Hello, World!")); base_layout = new VBoxLayout(); setLayout(base_layout); base_layout->sizePolicy(Expand); top_layout = new HBoxLayout(); base_layout->addItem(top_layout); top_layout->sizePolicy(Expand); top_layout->addWdiget(new Label(tr("Name:"))); text = new TextEdit(); top_layour->addWidget(text); button = new PushBotton(tr("Hello")); layout->addWidget(button); connect(text,SIGNAL(valueChanged()),this,SLOT(onEntryChanged()); connect(button,SIGNAL(pressed()),this,SLOT(onButtonClick()); } void onEntryChanged() { std::cout <<text->getText() << std::endl; } void onButtonClick() { std::cout << "Button Pressed" << std::endl; } } The second is more verbose but it is much readable, clear, intuitive code for an average C++ programmer. My $0.02 Artyom Beilis -------------- CppCMS - C++ Web Framework: http://cppcms.sf.net/ CppDB - C++ SQL Connectivity: http://cppcms.sf.net/sql/cppdb/