class Fl_Input : public Fl_Input_

There are some subclasses with different behavior:

• Fl_Float_Input
• Fl_Int_Input
• Fl_Multiline_Input
• Fl_Secret_Input

Mouse button 1	Moves the cursor to this point. Drag selects characters. Double click selects words. Triple click selects all text. Shift+click extends the selection.
Mouse button 2	Insert the current X selection at the cursor (unlike Motif this does not move the insertion point to the mouse). If the widget does not have the input focus (and thus no cursor) it puts the cursor where clicked and inserts the selection there.
Mouse button 3	Currently acts like button 1.
Backspace	Deletes one character to the left, or deletes the selected region.
Enter	May cause the callback, see when().
^A or Home	Go to start of line.
^B or Left	Move left
^C	Copy the selection to the X selection
^D or Delete	Deletes one character to the right or deletes the selected region. Due to silly historical X problems, the Delete key will act like Backspace until you type a "real" backspace.
^E or End	Go to the end of line.
^F or Right	Move right
^K	Delete to the end of line (next \n character) or deletes a single \n character. These deletions are all concatenated into the X selection.
^N or Down	Move down (for Fl_Multiline_Input only, otherwise it moves to the next input field).
^P or Up	Move up (for Fl_Multiline_Input only, otherwise it moves to the previous input field).
^Q or RightCtrl or Compose	Start a compose-character sequence. The next one or two keys typed define the character to insert. This also can be used to "quote" control characters.
^U	Delete everything.
^V or ^Y	Paste the X selection
^X or ^W	Copy the region to the X selection and delete it.
^Z or ^_	Undo. This is a single-level undo mechanism, but all adjacent deletions and insertions are concatenated into a single "undo". Often this will undo a lot more than you expected.
Shift+move	Move the cursor but also extend the selection.

Fl_Input::Fl_Input(int,int,int,int,const char* = 0);

The constructor takes a position, size, and label. Normally the label is printed to the left. This is not the value of the text field. The initial value is "".

const char* Fl_Input::value() const;

Return the current value. This returns a pointer to the Fl_Input's storage and is valid only until the next event is handled.

int Fl_Input::value(const char*);
int Fl_Input::value(const char*, int);

Change the text, and set the mark and the point to the end of it. The string is copied to the Fl_Input's own storage. Passing null is the same as "". This returns non-zero if the new value is different than the current one. You can use the second version to directly set the length if you know it already or want to put nul's in the text.

int Fl_Input::static_value(const char*);
int Fl_Input::static_value(const char*, int);

Change the text, and set the mark and the point to the end of it. The string is not copied. If the user edits the string it is copied to local storage then. This can save a great deal of time and memory if your program is rapidly changing the values of text fields, but this will only work if the passed string remains unchanged until either the Fl_Input is destroyed or value() is called again.

int Fl_Input::size() const;

Returns the number of characters in value(). This may be greater than strlen(value()) if there are nul characters in it.

char Fl_Input::index(int) const;

Same as value()[n], but may be faster in plausible implementations. No bounds checking is done.

Fl_When Fl_Widget::when() const;
void Fl_Widget::when(Fl_When);

Controls when callbacks are done. The following values are useful, the default value is FL_WHEN_RELEASE:
• 0 : The callback is not done, but changed() is turned on.
• FL_WHEN_CHANGED : The callback is done each time the text is changed by the user.
• FL_WHEN_RELEASE : The callback will be done when this widget loses the focus, including when the window is unmapped. This is a useful value for text fields in a panel where doing the callback on every change is wasteful. However the callback will also happen if the mouse is moved out of the window, which means it should not do anything visible (like pop up an error message). You might do better setting this to zero, and scanning all the items for changed() when the OK button on a panel is pressed.
• FL_WHEN_ENTER_KEY : If the user types the Enter key, the entire text is selected, and the callback is done if the text has changed. Normally the Enter key will navigate to the next field (or insert a newline for a Fl_Mulitline_Input), this changes the behavior.
• FL_WHEN_ENTER_KEY|FL_WHEN_NOT_CHANGED: The Enter key will do the callback even if the text has not changed. Useful for command fields.

int Fl_Widget::changed() const;
void Fl_Widget::set_changed();
void Fl_Widget::clear_changed();

This value is true if the current value has been edited. It is turned off by value(x) and just before doing a callback (the callback can turn it back on if desired).

Fl_Font Fl_Input::textfont() const;
void Fl_Input::textfont(Fl_Font);
uchar Fl_Input::textsize() const;
void Fl_Input::textsize(uchar);
Fl_Color Fl_Input::textcolor() const;
void Fl_Input::textcolor(Fl_Color);

Get or set the font, font size, or color of the text. The default is normal-sized Helvetica and black.

Fl_Color Fl_Input::cursor_color() const;
void Fl_Input::cursor_color(Fl_Color);

Get or set the color of the cursor. This is black by default.

class Fl_Float_Input : public Fl_Input

You may want a Fl_Value_Input or Fl_Value_Output instead.

Fl_Float_Input::Fl_Float_Input(int x,int y,int w,int h,const char* l = 0);

class Fl_Int_Input : public Fl_Input

You may want a Fl_Value_Input or Fl_Value_Output instead, with the step() set to 1.

Fl_Int_Input::Fl_Int_Input(int x,int y,int w,int h,const char* l = 0);

class Fl_Multiline_Input : public Fl_Input

This is far from the nirvana of text editors, and is probably only good for small bits of text, 10 lines at most. I think fltk can be used to write a powerful text editor, but it is not going to be a built-in feature. Powerful text editors in a toolkit are a big source of bloat.

Fl_Multiline_Input::Fl_Multiline_Input(int x,int y,int w,int h,const char* l = 0);

class Fl_Secret_Input : public Fl_Input

Fl_Secret_Input::Fl_Secret_Input(int x,int y,int w,int h,const char* l = 0);

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