I am generally new to Ruby and more specifically FXRuby. I come from a
Java background, but have been recently looking at SmallTalk and Ruby
and I wanted to compare and contrast the languages. I have a library in
Java that will allow me to bind a class attribute directly to a GUI
control. It uses JavaBean technology and the PropertyChangeEvent
signals that are sent every time the value changes. SmallTalk provides
this support as part of the core language. My question is how do I do
that with Ruby?
For example, I have a BankAccount class (yes I know its a toy app, but
it will help me understand what to do) with a "balance" attribute.
The
BankAccount class works wonderfully by itself. I have a method to
deposit and a method to withdraw funds from this BankAccount class. I
want to be able to set up a button like this:
FXButton.new(window, "&Deposit").connect(SEL_COMMAND) {
@account.deposit
200 }
And as a result of that action have the FXTextField automatically update
itself with the new balance. I don''t see a lot of examples of this
type
of thing, and I am not even sure if it is possible (it must be). Has
anyone had any luck with this?
Berin Loritsch wrote:> I am generally new to Ruby and more specifically FXRuby. I come from a > Java background, but have been recently looking at SmallTalk and Ruby > and I wanted to compare and contrast the languages. I have a library in > Java that will allow me to bind a class attribute directly to a GUI > control. It uses JavaBean technology and the PropertyChangeEvent > signals that are sent every time the value changes. SmallTalk provides > this support as part of the core language. My question is how do I do > that with Ruby? > > For example, I have a BankAccount class (yes I know its a toy app, but > it will help me understand what to do) with a "balance" attribute. The > BankAccount class works wonderfully by itself. I have a method to > deposit and a method to withdraw funds from this BankAccount class. I > want to be able to set up a button like this: > > FXButton.new(window, "&Deposit").connect(SEL_COMMAND) { @account.deposit > 200 } > > And as a result of that action have the FXTextField automatically update > itself with the new balance. I don''t see a lot of examples of this type > of thing, and I am not even sure if it is possible (it must be). Has > anyone had any luck with this?Berin, There are two ways I know of doing this. Fox itself provides one way, FXDataTargets. There is an example in the FXRuby distribution. Another way is to use two libraries I have developed: FoxTails and Observable, available at http://raa.ruby-lang.org. Briefly, Observable lets you designate an attribute as "observable", in which case various parts of your app can register to be informed when the value changes. FoxTails uses this to wire up widgets like text fields, sliders, scroll bars, etc. (There are some other things in FoxTails, too.) Your example might look something like this: --------------------------------- require ''foxtails'' include Fox include FoxTails class Account extend Observable observable :balance def deposit amt self.balance += amt # Don''t use @balance, or observers not notified. end end class AccountWindow < FXMainWindow def initialize(*args) super @account = Account.new @account.balance = 0 FXButton.new(self, "&Deposit").connect(SEL_COMMAND) { @account.deposit 200 } int_field = FTIntegerField.new(self, 10, @account, :balance, FRAME_SUNKEN) end def create super show end end class AccountApp < FTApp def initialize super("Account", "TEST") FoxTails.get_standard_icons AccountWindow.new(self, "Account") end end AccountApp.new.run --------------------------------- You can also register for notification from non-gui code, using "when_" clauses: some_account.when_balance CHANGES do |new_bal, old_bal| ... end The CHANGES thingy is just something that matches the new value, using ruby''s === matching. CHANGES is actually the class Object, which matches everything. (Because === is =~ for strings, you can use regexes to match strings. Also, you can extend it as you wish by defining === in your classes.) This is documented in the observable project. FoxTails is currently for Fox 1.0, but I have a "shim" file you can include to get most of it to work with 1.2. I apologize in advance for the state of the documentation, but at least there are examples, and the FT*Field classes have almost the same api as the FX*Field classes. Btw, the current version of FoxTails has a nice way of generating text fields, check/radio buttons, option menus, and static text using a syntax much like good ol'' printf. The fields are automatically wired up to the observable attrs that you specify. See examples/fields.rb.
Joel VanderWerf wrote:> Berin Loritsch wrote: > >> I am generally new to Ruby and more specifically FXRuby. I come from >> a Java background, but have been recently looking at SmallTalk and >> Ruby and I wanted to compare and contrast the languages. I have a >> library in Java that will allow me to bind a class attribute directly >> to a GUI control. It uses JavaBean technology and the >> PropertyChangeEvent signals that are sent every time the value >> changes. SmallTalk provides this support as part of the core >> language. My question is how do I do that with Ruby? >> >> For example, I have a BankAccount class (yes I know its a toy app, >> but it will help me understand what to do) with a "balance" >> attribute. The BankAccount class works wonderfully by itself. I >> have a method to deposit and a method to withdraw funds from this >> BankAccount class. I want to be able to set up a button like this: >> >> FXButton.new(window, "&Deposit").connect(SEL_COMMAND) { >> @account.deposit 200 } >> >> And as a result of that action have the FXTextField automatically >> update itself with the new balance. I don''t see a lot of examples of >> this type of thing, and I am not even sure if it is possible (it must >> be). Has anyone had any luck with this? > > > Berin, > > There are two ways I know of doing this. Fox itself provides one way, > FXDataTargets. There is an example in the FXRuby distribution. > > Another way is to use two libraries I have developed: FoxTails and > Observable, available at http://raa.ruby-lang.org. Briefly, Observable > lets you designate an attribute as "observable", in which case various > parts of your app can register to be informed when the value changes. > FoxTails uses this to wire up widgets like text fields, sliders, > scroll bars, etc. (There are some other things in FoxTails, too.)Thank you. Are FoxTails and Observable gems? Or do I have to download and install them separately?> > Your example might look something like this: > > --------------------------------- > require ''foxtails'' > > include Fox > include FoxTails > > class Account > extend Observable > > observable :balance > def deposit amt > self.balance += amt > # Don''t use @balance, or observers not notified. > end > end > > class AccountWindow < FXMainWindow > def initialize(*args) > super > > @account = Account.new > @account.balance = 0 > > FXButton.new(self, "&Deposit").connect(SEL_COMMAND) { > @account.deposit 200 > } > > int_field = FTIntegerField.new(self, 10, @account, :balance, > FRAME_SUNKEN) > end > > def create > super > show > end > end > > class AccountApp < FTApp > def initialize > super("Account", "TEST") > FoxTails.get_standard_icons > AccountWindow.new(self, "Account") > end > end > > AccountApp.new.run > --------------------------------- > > You can also register for notification from non-gui code, using > "when_" clauses: > > some_account.when_balance CHANGES do |new_bal, old_bal| > ... > end > > The CHANGES thingy is just something that matches the new value, using > ruby''s === matching. CHANGES is actually the class Object, which > matches everything. (Because === is =~ for strings, you can use > regexes to match strings. Also, you can extend it as you wish by > defining === in your classes.) This is documented in the observable > project. > > FoxTails is currently for Fox 1.0, but I have a "shim" file you can > include to get most of it to work with 1.2. I apologize in advance for > the state of the documentation, but at least there are examples, and > the FT*Field classes have almost the same api as the FX*Field classes. > > Btw, the current version of FoxTails has a nice way of generating text > fields, check/radio buttons, option menus, and static text using a > syntax much like good ol'' printf. The fields are automatically wired > up to the observable attrs that you specify. See examples/fields.rb. > _______________________________________________ > fxruby-users mailing list > fxruby-users@rubyforge.org > http://rubyforge.org/mailman/listinfo/fxruby-users >