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digitalmars.D.learn - Subclass method -distorted now put again

reply June <somewhere so.com> writes:
dwt.widget.Text has method
 
void setText  (char[] string); 
Sets the contents of the receiver to the given string. 

In my application I use many of these text boxes each with a name so I need a
function 

void setText(char[] name, char[] text){
   name.setText(text);}

How can  I bring this into my program ?
May 06 2008
parent reply Ary Borenszweig <ary esperanto.org.ar> writes:
June escribió:

 dwt.widget.Text has method
  
 void setText  (char[] string); 
 Sets the contents of the receiver to the given string.
 
 In my application I use many of these text boxes each with a name so I need a
function 
 
 void setText(char[] name, char[] text){
    name.setText(text);}



name.setText(text) ?

But name is of type char[]


 
 How can  I bring this into my program ?



Maybe you could show what you do now, and how you would like to have it 
if you were able to do what you want. I don't understand what you are 
trying to do. :(
May 07 2008
parent reply June <somewhere so.com> writes:
Ary Borenszweig Wrote:


 June escribió:

 dwt.widget.Text has method
  
 void setText  (char[] string); 
 Sets the contents of the receiver to the given string.
 
 In my application I use many of these text boxes each with a name so I need a
function 
 
 void setText(char[] name, char[] text){
    name.setText(text);}



 name.setText(text) ?
 
 But name is of type char[]
 

 
 How can  I bring this into my program ?



 Maybe you could show what you do now, and how you would like to have it 
 if you were able to do what you want. I don't understand what you are 
 trying to do. :(




In a class 'Room'
I make a text box called  "speaker', and another called 'radio' etc
Text speaker = new Text;

all blank atm

In another module  'town' I create instance of 'room' and 
now I want to set the text in each
speaker.setText("Wallplate");
radio.setText("Valves")

So Text class has  method  'setText(char[])

In 'town' I want to make another method like 
setText(name[],text[]);

different parameters to setText () in Text- I need to find out how to do it
please?
May 07 2008
next sibling parent BLS <nanali nospam-wanadoo.fr> writes:
June schrieb:

 Ary Borenszweig Wrote:
 

 June escribió:

 dwt.widget.Text has method
  
 void setText  (char[] string); 
 Sets the contents of the receiver to the given string.

 In my application I use many of these text boxes each with a name so I need a
function 

 void setText(char[] name, char[] text){
    name.setText(text);}




 But name is of type char[]


 How can  I bring this into my program ?



 if you were able to do what you want. I don't understand what you are 
 trying to do. :(



 
 In a class 'Room'
 I make a text box called  "speaker', and another called 'radio' etc
 Text speaker = new Text;
 
 all blank atm
 
 In another module  'town' I create instance of 'room' and 
 now I want to set the text in each
 speaker.setText("Wallplate");
 radio.setText("Valves")
 
 So Text class has  method  'setText(char[])
 
 In 'town' I want to make another method like 
 setText(name[],text[]);
 
 different parameters to setText () in Text- I need to find out how to do it
please?




Hi June,

class room
{
   void setText(char[] roomtext)
   {
    // print or whatever you wanna do with roomtext
   }
}

class town : room
{
  void setText(char[] roomtext, char[] towntext)
  {
   super.setText(roomtext); //  calls room.setText()
   // do something with towntext
  }
}

hth bjoern
May 07 2008
prev sibling parent reply BCS <BCS pathlink.com> writes:
June wrote:

 Ary Borenszweig Wrote:
 
 

June escribió:


dwt.widget.Text has method
 
void setText  (char[] string); 
Sets the contents of the receiver to the given string.

In my application I use many of these text boxes each with a name so I need a
function 

void setText(char[] name, char[] text){
   name.setText(text);}



name.setText(text) ?

But name is of type char[]



How can  I bring this into my program ?



Maybe you could show what you do now, and how you would like to have it 
if you were able to do what you want. I don't understand what you are 
trying to do. :(



 
 
 In a class 'Room'
 I make a text box called  "speaker', and another called 'radio' etc
 Text speaker = new Text;
 
 all blank atm
 
 In another module  'town' I create instance of 'room' and 
 now I want to set the text in each
 speaker.setText("Wallplate");
 radio.setText("Valves")
 
 So Text class has  method  'setText(char[])
 
 In 'town' I want to make another method like 
 setText(name[],text[]);
 
 different parameters to setText () in Text- I need to find out how to do it
please?




so "setText("speaker", "foo") would call speaker.setText("foo")?

D doesn't support this directly, however you could do it manually

void setText(char[] name, char[] text)
{
	switch(name)
	{
		case "speaker": speaker.setText(text); break;
		case "radio":     radio.setText(text); break;
		default: assert(false);
	}
}
May 07 2008
parent reply "Jarrett Billingsley" <kb3ctd2 yahoo.com> writes:
"BCS" <BCS pathlink.com> wrote in message 
news:fvsdh5$2hii$11 digitalmars.com...


 so "setText("speaker", "foo") would call speaker.setText("foo")?

 D doesn't support this directly, however you could do it manually

 void setText(char[] name, char[] text)
 {
 switch(name)
 {
 case "speaker": speaker.setText(text); break;
 case "radio":     radio.setText(text); break;
 default: assert(false);
 }
 }



In this case, it seems like keeping the controls in an AA would make a lot 
more sense.

class MyWindow
{
    Control[char[]] controls;

    this()
    {
        controls["speaker"] = new Slider();
        controls["radio"] = new Button();
    }

    void setText(char[] name, char[] text)
    {
        controls[name].setText(text);
    }
}
May 07 2008
parent reply June <somewhere so.com> writes:
Jarrett Billingsley Wrote:


 "BCS" <BCS pathlink.com> wrote in message 
 news:fvsdh5$2hii$11 digitalmars.com...
 

 so "setText("speaker", "foo") would call speaker.setText("foo")?






YES


 D doesn't support this directly, however you could do it manually

 void setText(char[] name, char[] text)
 {
 switch(name)
 {
 case "speaker": speaker.setText(text); break;  What is diff here? -none
 case "radio":     radio.setText(text); break;
 default: assert(false);
 }
 }



 In this case, it seems like keeping the controls in an AA would make a lot 
 more sense.
 
 class MyWindow
 {
     Control[char[]] controls;
 
     this()
     {
         controls["speaker"] = new Slider();
         controls["radio"] = new Button();
     }
 
     void setText(char[] name, char[] text)
     {
         controls[name].setText(text);
     }
 } 
 
 



I want to add a function to 'dwt.widgets.Text' that takes two char arrays and
alters the text in  an instance of dwt.widgets.Text' 

dwt.widgets.Text'  only has a function  that takes one char array ?  
setText(char[] text)

Sorry if confusing a womans perogative no?
May 07 2008
next sibling parent reply "Jarrett Billingsley" <kb3ctd2 yahoo.com> writes:
"June" <somewhere so.com> wrote in message 
news:fvtbau$p5q$1 digitalmars.com...


 Dont see how this applies .
 I want to add a function to 'dwt.widgets.Text' that takes two char arrays 
 and alters the text in  an instance of dwt.widgets.Text'

 dwt.widgets.Text'  only has a function  that takes one char array ? 
 setText(char[] text)



It applies because it's exactly what you want to do ;)

You have several Text objects, yes?  And each one has a name?  You can't 
just "add a method" to Text and have it "find" a text box of a given name, 
you have to store those text boxes and perform the name lookup yourself. 
Remember that a class method only operates on a single object; if you 
subclassed Text, you wouldn't be able to access other instances of Text 
besides 'this' unless you stored them somewhere.

So instead of doing something like

class MyWindow
{
    Text foo;
    Text bar;

    this()
    {
        foo = new Text("hi!");
        bar = new Text("bye!");
    }
}

You can instead store them in an associative array which maps from names to 
text boxes:

class MyWindow
{
    Text[char[]] textBoxes;

    this()
    {
        textBoxes["foo"] = new Text("hi!");
        textBoxes["bar"] = new Text("bye!");
    }
}

Then, you can add a method to MyWindow that will take a name and a string, 
and will set the text box with the given name to the given string:

// defined as a method of MyWindow
void setText(char[] name, char[] s)
{
    textBoxes[name].setText(s);
}

Keep in mind that D is a statically-compiled language, unlike languages like 
Python, and so dynamic (runtime) lookup of variables and members is, in 
general, not possible.  Which is why you have to store the mapping from 
names to controls yourself.
May 07 2008
parent reply June <somewhere so.com> writes:
Jarrett Billingsley Wrote:


 "June" <somewhere so.com> wrote in message 
 news:fvtbau$p5q$1 digitalmars.com...
 

 Dont see how this applies .
 I want to add a function to 'dwt.widgets.Text' that takes two char







 and alters the text in  an instance of dwt.widgets.Text'

 dwt.widgets.Text'  only has a function  that takes one char







 setText(char[] text)



 It applies because it's exactly what you want to do ;)
 
 You have several Text objects, yes?  And each one has a name?  You




 just "add a method" to Text and have it "find" a text box of a given




 you have to store those text boxes and perform the name lookup




 Remember that a class method only operates on a single object; if




 subclassed Text, you wouldn't be able to access other instances of




 besides 'this' unless you stored them somewhere.
 
 So instead of doing something like
 
 class MyWindow
 {
     Text foo;
     Text bar;
 
     this()
     {
         foo = new Text("hi!");
         bar = new Text("bye!");
     }
 }
 
 You can instead store them in an associative array which maps from




 text boxes:
 
 class MyWindow
 {
     Text[char[]] textBoxes;
 
     this()
     {
         textBoxes["foo"] = new Text("hi!");
         textBoxes["bar"] = new Text("bye!");
     }
 }
 
 Then, you can add a method to MyWindow that will take a name and a




 and will set the text box with the given name to the given string:
 
 // defined as a method of MyWindow
 void setText(char[] name, char[] s)
 {
     textBoxes[name].setText(s);
 }
 
 Keep in mind that D is a statically-compiled language, unlike




 Python, and so dynamic (runtime) lookup of variables and members is,




 general, not possible.  Which is why you have to store the mapping




 names to controls yourself. 
 
 



So much extraneous stuff


textBoxes["foo"] = new Text("hi!");  using 'dwt.widgets.Text' ,,this







I understand the need to  store the names point you are making but
surely I can override the 'dwt.widgets.Text's '  setText(text) 
function some way?
May 08 2008
parent reply Ary Borenszweig <ary esperanto.org.ar> writes:
June escribió:

 Jarrett Billingsley Wrote:
 

 "June" <somewhere so.com> wrote in message 
 news:fvtbau$p5q$1 digitalmars.com...


 Dont see how this applies .
 I want to add a function to 'dwt.widgets.Text' that takes two char







 and alters the text in  an instance of dwt.widgets.Text'

 dwt.widgets.Text'  only has a function  that takes one char







 setText(char[] text)




 You have several Text objects, yes?  And each one has a name?  You




 just "add a method" to Text and have it "find" a text box of a given




 you have to store those text boxes and perform the name lookup




 Remember that a class method only operates on a single object; if




 subclassed Text, you wouldn't be able to access other instances of




 besides 'this' unless you stored them somewhere.

 So instead of doing something like

 class MyWindow
 {
     Text foo;
     Text bar;

     this()
     {
         foo = new Text("hi!");
         bar = new Text("bye!");
     }
 }

 You can instead store them in an associative array which maps from




 text boxes:

 class MyWindow
 {
     Text[char[]] textBoxes;

     this()
     {
         textBoxes["foo"] = new Text("hi!");
         textBoxes["bar"] = new Text("bye!");
     }
 }

 Then, you can add a method to MyWindow that will take a name and a




 and will set the text box with the given name to the given string:

 // defined as a method of MyWindow
 void setText(char[] name, char[] s)
 {
     textBoxes[name].setText(s);
 }

 Keep in mind that D is a statically-compiled language, unlike




 Python, and so dynamic (runtime) lookup of variables and members is,




 general, not possible.  Which is why you have to store the mapping




 names to controls yourself. 



 So much extraneous stuff
 

 textBoxes["foo"] = new Text("hi!");  using 'dwt.widgets.Text' ,,this






 
 I understand the need to  store the names point you are making but
 surely I can override the 'dwt.widgets.Text's '  setText(text) 
 function some way?



You can override it by defining a method with the same name and signature:

class YourClass : Text {

   override void setText(char[] text) {
     // your code...
   }

}

However, if you define a method "void setText(char[] name, char[] text)" 
in YourClass, that's not an override: that's an overload. And I'm not 
sure, but in that case, if you still want to be able to use the old 
setText, you need to make an alias for it:

alias setText setText;
May 07 2008
parent June <somewhere so.com> writes:
Ary Borenszweig wrote:


 Completely lost now .
 So much extraneous stuff
 

 textBoxes["foo"] = new Text("hi!");  using 'dwt.widgets.Text'
 ,,this






 work
 
 I understand the need to  store the names point you are making but
 surely I can override the 'dwt.widgets.Text's '  setText(text)
 function some way?



 You can override it by defining a method with the same name and
 signature:
 
 class YourClass : Text {
 
    override void setText(char[] text) {
      // your code...
    }
 
 }
 
 However, if you define a method "void setText(char[] name, char[]
 text)" in YourClass, that's not an override: that's an overload. And
 I'm not sure, but in that case, if you still want to be able to use
 the old setText, you need to make an alias for it:
 
 alias setText setText;



Thanks thats what I am seeking to do .I will try it out
May 08 2008
prev sibling parent BCS <BCS pathlink.com> writes:
void setText(char[] name, char[] text)
{
switch(name)
{
case "speaker": speaker.setText(text); break;










  What is diff here? -none



I don't understand your question.


case "radio":     radio.setText(text); break;
default: assert(false);
}
}









duplicating much of Jarrett's comments:


In this case, it seems like keeping the controls in an AA would make a lot 
more sense.

class MyWindow
{
    Control[char[]] controls;

    this()
    {
        controls["speaker"] = new Slider();
        controls["radio"] = new Button();
    }

    void setText(char[] name, char[] text)
    {
        controls[name].setText(text);
    }
} 



 Dont see how this applies .



I think Jarrett is solving a more general problem that you are looking 
at. Replace 'Control', 'Slider' and 'Button' with 'Text' and it might be 
closer to what you want.

Independently:


 I want to add a function to 'dwt.widgets.Text' that takes two char
 arrays and alters the text in  an instance of dwt.widgets.Text'



Unless you are willing to alter the source code for 'dwt.widgets.Text' 
(and end up with a non-standard version) you can't add a function to 
'dwt.widgets.Text'. The best you can do is derive a new class from it 
and add your function to that.

Also, I don't think adding the function to Text will work anyway 
because, If I understand you correctly, you want to call setText on 
different instances of Text based on 'name'. For this to work the 
setText(name,text) function needs to be attached to whatever holds the 
reference to the Text instance.

Jumping back to the case you described befor this requiters that the new 
function be attached to the Room class because it has the 'radio' and 
'speaker' variables:

class Room
{
   Text speaker;
   Text radio;

   void setText(char[] name, char[] text)
   {
     switch(name)
     {
       case "speaker": speaker.setText(text); break;
       case "radio":     radio.setText(text); break;
       default: assert(false);
     }
   }

   ... // everything else
}
May 07 2008