Thread: Writing a text editor

I wrote this
but i can't handle the entered strings.

Code:

#define LINE	        60
#define COL		100

class Editor
{
private:
	char buff[LINE][COL];
public:
	friend istream& operator >> (istream&, Editor&);
	friend ostream& operator << (ostream&, const Editor&);

};

istream& operator >> (istream& input, Editor& str)
{
	for (int i = 0; i < LINE; i++)
		for (int j = 0; j < COL; j++)
			input >> str.buff[i][j];

	return input;
}

ostream& operator << (ostream& output, const Editor& str)
{
	for (int i = 0; i < LINE; i++)
		for (int j = 0; j < COL; j++)
			output << str.buff[i][j];

	return output;
}

how could i control it that if user pressed enter, it goes to next line?

Look at the FAQ about "How do I input data without user hitting enter" - which despite the title is actually close to "doing to the right thing when the user hits enter" too.

--
Mats

I couldn't find any thing, it returns no result
---------------------------
I found it

but it doesn't help!

I need something that return the character that user is entered right the moment so I check it and if it was '\n' string will go to another line

-------------------------------------
hope you understand what I mean

I would also say that having a operator<< or operator>> on the "Editor" is probably not the right thing - you probably should decouple the basic editor and the CONTENT that is being edited - sure, the editor needs to have some sort of handle to get hold of the content, but you do not want to write the editor to the file, you want to write the content to a file.

Better to get your object design roughly right to begin with than to find out later that it doesn't work

[A good editor can edit multiple files, but I don't think you'd want two differnet Editor objects to do that - just two instances of content].

--
Mats

You need either a list or a vector. A double-linked list is quite practical, as you often need to find the line "up" from where you are, as well as being able to walk "down" the list.

A vector (or fixed array, as Salem suggests) is somewhat easier to implement, but has a drawback on large files when inserting new lines (because every line after the new line will have to be moved).

As I suggested earlier, you can also have a hybrid approach of "blocks of lines" in a linked list - so for example a block may be a maximum of 16 lines.

The best way is that you "hide" how the lines are actually stored inside a class - that way, you can change the actuals of the implementation as and when you have a "better idea", without having to change the entire rest of the code.

--
Mats

Originally Posted by behzad_shabani

I have a little knowledge of C++,
I have never worked with vectors and I don't know what it is!

That tells me that you do not know quite enough to solve the task - yet at least.

A vector is essentialy a dynamically sizing array - so you just add objects to it as you need, and in grows to accomodate the number of elements you have.

--
Mats

std::string line;
cin.getline(line);