Programming Forums > Application Development > Java

xavier · Jan 24th, 2005, 3:23 AM

I have to make a grafical aplication. It takes it's input from a file where i have a name on each line. It has to have 2 buttons : UP and DOWN, in order to show 3 names at a time. Example:
On pressing down it will show: first 3 names, If pressed again it will show the next 3.. if u press up .. the first three .. and so on.

I'm not sure how to do this . I tride to group 3 lines at a time in a string ... but i don't know how to make it stop printing. I press DOWN once ...it showld print the first 3 then to stop ... until i've pressed it again .... help

EdSalamander · Jan 24th, 2005, 9:37 AM

Show us your code, it'll help us help you.

xavier · Jan 24th, 2005, 11:52 AM

Well i'd post if there was something to post. I wrote an aplication that prints the contents of a file.... I need some ideeas on how to do the 3 line movement...3 lines up .. 3 lines down

Dizzutch · Jan 24th, 2005, 12:54 PM

stick all the lines in some data structure, and print the next three. doubly-linked list would work.

xavier · Jan 24th, 2005, 1:52 PM

how can i make it start printing from the 5-th line for example...?

EdSalamander · Jan 24th, 2005, 9:59 PM

One way you could do it...
First, have your program copy all the names into an array, one name/line per index, then you can reference any line/name with that index in the array minus 1. For example, if you wanted to display the 5th, 6th and 7th lines, you print out array[i-1], array[i] and array[i+1] where i = 5. Your up and down arrows then would decrease or increase i by three (respectively) and update/rewrite the display.

xavier · Jan 25th, 2005, 12:43 PM

Ok, .... how do i add them into an array ? what type of array? And ... after i press the down button, let's say it shows the first 3 names. after.. on pressing the button again it showld continue from where it was ... hmm ... i haven't tried anything yet .. but on the other hand i have no ideea on how to do that .

But first ... the array .....?

marcusami · Jan 25th, 2005, 5:50 PM

This is a bit brute forced and just somethign i wrote out, not exact code, but hopefully it will give u an idea. It first creates 9 Name cells, then u get names from user and it puts them n cells; then if a button is clicked up display the first three; if this is done again show next three, and if pushed down go down 3.
I hope this helps it might be confusing more than helping

String [] Name = new String[8];
for(int index=0; index<Name.length; index++){
Name[index] = userName;
}

int Num =0;
if(buttonClickedUp){

for(Num; Num <=2; Num++){
System.out.println(Name[Num]);

if(buttonClickUp){

for(Num=3; num<=5; num++);
System.out.println(Name[Num]);
}

if(buttonClickDown){

for(Num=2; num >=0; num--;
System.out.println(Name[Num]);
}
}

xavier · Jan 26th, 2005, 12:21 AM

(Toggle Plain Text)

String[] c=new String[300];
try{
			fr=new FileReader("name.txt");
			bfr=new BufferedReader(fr);
			int i=0;

			for(;;){

				String lCrt=bfr.readLine();
				if(lCrt==null)break;
				c[i]=lCrt;
				i++;
				System.out.println(c[i]); //test to see if it works
			
			}
			bfr.close();
			}catch(IOException e){
						System.out.println(e);
						System.exit(1);}

I keep getting "null".... i don't know why...

xavier · Jan 26th, 2005, 11:03 PM

....Help.... why do i keep getting "null"?

Jan 24th, 2005, 3:23 AM	#1
xavier Professional Programmer Join Date: Oct 2004 Location: .ro Posts: 383 Rep Power: 4	Grafical aplication I have to make a grafical aplication. It takes it's input from a file where i have a name on each line. It has to have 2 buttons : UP and DOWN, in order to show 3 names at a time. Example: On pressing down it will show: first 3 names, If pressed again it will show the next 3.. if u press up .. the first three .. and so on. I'm not sure how to do this . I tride to group 3 lines at a time in a string ... but i don't know how to make it stop printing. I press DOWN once ...it showld print the first 3 then to stop ... until i've pressed it again .... help __________________ Don't take life too seriously, it's not permanent !

Jan 24th, 2005, 9:37 AM	#2
EdSalamander Programmer Join Date: Dec 2004 Location: Tucson, AZ, USA Posts: 80 Rep Power: 4	Show us your code, it'll help us help you. __________________ I can pick my friends. And I can pick my nose. So, why can't I pick my friend's nose?

Jan 24th, 2005, 11:52 AM	#3
xavier Professional Programmer Join Date: Oct 2004 Location: .ro Posts: 383 Rep Power: 4	Well i'd post if there was something to post. I wrote an aplication that prints the contents of a file.... I need some ideeas on how to do the 3 line movement...3 lines up .. 3 lines down __________________ Don't take life too seriously, it's not permanent !

Jan 24th, 2005, 12:54 PM	#4
Dizzutch Professional Programmer Join Date: Dec 2004 Location: Worcester, MA Posts: 441 Rep Power: 4	stick all the lines in some data structure, and print the next three. doubly-linked list would work. __________________ naked pictures of you \| PFO F@H stats

Jan 24th, 2005, 1:52 PM	#5
xavier Professional Programmer Join Date: Oct 2004 Location: .ro Posts: 383 Rep Power: 4	how can i make it start printing from the 5-th line for example...? __________________ Don't take life too seriously, it's not permanent !

Jan 24th, 2005, 9:59 PM	#6
EdSalamander Programmer Join Date: Dec 2004 Location: Tucson, AZ, USA Posts: 80 Rep Power: 4	One way you could do it... First, have your program copy all the names into an array, one name/line per index, then you can reference any line/name with that index in the array minus 1. For example, if you wanted to display the 5th, 6th and 7th lines, you print out array[i-1], array[i] and array[i+1] where i = 5. Your up and down arrows then would decrease or increase i by three (respectively) and update/rewrite the display. __________________ I can pick my friends. And I can pick my nose. So, why can't I pick my friend's nose?

Jan 25th, 2005, 12:43 PM	#7
xavier Professional Programmer Join Date: Oct 2004 Location: .ro Posts: 383 Rep Power: 4	Ok, .... how do i add them into an array ? what type of array? And ... after i press the down button, let's say it shows the first 3 names. after.. on pressing the button again it showld continue from where it was ... hmm ... i haven't tried anything yet .. but on the other hand i have no ideea on how to do that . But first ... the array .....? __________________ Don't take life too seriously, it's not permanent !

Jan 25th, 2005, 5:50 PM	#8
marcusami Newbie Join Date: Jan 2005 Location: Ky Posts: 3 Rep Power: 0	This is a bit brute forced and just somethign i wrote out, not exact code, but hopefully it will give u an idea. It first creates 9 Name cells, then u get names from user and it puts them n cells; then if a button is clicked up display the first three; if this is done again show next three, and if pushed down go down 3. I hope this helps it might be confusing more than helping String [] Name = new String[8]; for(int index=0; index<Name.length; index++){ Name[index] = userName; } int Num =0; if(buttonClickedUp){ for(Num; Num <=2; Num++){ System.out.println(Name[Num]); if(buttonClickUp){ for(Num=3; num<=5; num++); System.out.println(Name[Num]); } if(buttonClickDown){ for(Num=2; num >=0; num--; System.out.println(Name[Num]); } } __________________ [color=DarkSlateGray] Marcus

Jan 26th, 2005, 12:21 AM	#9
xavier Professional Programmer Join Date: Oct 2004 Location: .ro Posts: 383 Rep Power: 4	(Toggle Plain Text) String[] c=new String[300]; try{ fr=new FileReader("name.txt"); bfr=new BufferedReader(fr); int i=0; for(;;){ String lCrt=bfr.readLine(); if(lCrt==null)break; c[i]=lCrt; i++; System.out.println(c[i]); //test to see if it works } bfr.close(); }catch(IOException e){ System.out.println(e); System.exit(1);} String[] c=new String[300]; try{ fr=new FileReader("name.txt"); bfr=new BufferedReader(fr); int i=0; for(;;){ String lCrt=bfr.readLine(); if(lCrt==null)break; c[i]=lCrt; i++; System.out.println(c[i]); //test to see if it works } bfr.close(); }catch(IOException e){ System.out.println(e); System.exit(1);} I keep getting "null".... i don't know why... __________________ Don't take life too seriously, it's not permanent !

Jan 26th, 2005, 11:03 PM	#10
xavier Professional Programmer Join Date: Oct 2004 Location: .ro Posts: 383 Rep Power: 4	....Help.... why do i keep getting "null"? __________________ Don't take life too seriously, it's not permanent !

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Programming Forums > Application Development > Java

Grafical aplication