Make Fl_String and Fl_Int_Vector private (#789)

- add CMake option 'OPTION_USE_STD'
- add configure option '--enable-use_std'
- move FL/Fl_String.H to src/Fl_String.H
- move FL/Fl_Int_Vector.H to src/Fl_Int_Vector.H
- remove Fl_String from demo program examples/callbacks.cxx
- remove Fl_Int_Vector from public header FL/Fl_Table.H
- some methods of Fl_Table are no longer inline
- add CMake option OPTION_USE_STD to allow std::string in some
  selected functions and methods

Experimental, may be removed before release:

- use either Fl_Int_Vector or std::vector in Fl_Table depending
  on CMake OPTION_USE_STD or configure --enable-use_std

Move all fl_filename* functions that use Fl_String to fluid

Main changes in fluid:
 - add fluid_filename.h and .cxx
 - include "fluid_filename.h" rather than <FL/filename.H>

Update fl_input(), fl_password() and test/ask

- add maxchar parameter to fl_input() and fl_password()
- fl_input_str() and fl_password_str() are optional and return
  std::string if enabled (FLTK_USE_STD)

1 files changed, 12 insertions, 3 deletions

diff --git a/src/Fl_Message.cxx b/src/Fl_Message.cxx
index 246835d6c..ee3f61cd3 100644
--- a/src/Fl_Message.cxx
+++ b/src/Fl_Message.cxx
@@ -445,9 +445,18 @@ Fl_Box *Fl_Message::message_icon() {
 /**
   Does all Fl_Message window internals for messages with a text input field.
 
+  \param[in] fmt      printf style format used in the user function call
+  \param[in] ap       argument list provided by the user function call
+  \param[in] defstr   default string given by the user
+  \param[in] type     either FL_NORMAL_INPUT or FL_SECRET_INPUT (password)
+  \param[in] maxchar  max. number of allowed characters (not bytes)
+  \param[in] str      true: return type is string, false: internal buffer
+
+  \returns    pointer to string or NULL if cancel or escape were hit
+
   \see innards()
 */
-const char *Fl_Message::input_innards(const char *fmt, va_list ap, const char *defstr, uchar type, int maxchar) {
+const char *Fl_Message::input_innards(const char *fmt, va_list ap, const char *defstr, uchar type, int maxchar, bool str) {
   message_->position(60, 10);
   input_->type(type);
   input_->show();
@@ -465,7 +474,7 @@ const char *Fl_Message::input_innards(const char *fmt, va_list ap, const char *d
 
     int size = input_->size() + 1;
 
-    if (maxchar < 0) { // need to store the value in pre-allocated buffer
+    if (!str) { // need to store the value in pre-allocated buffer
 
       // The allocated input buffer starts with size 0 and is allocated
       // in multiples of 128 bytes >= size. If both the size and the pointer
@@ -485,7 +494,7 @@ const char *Fl_Message::input_innards(const char *fmt, va_list ap, const char *d
       input_buffer_[input_->size()] = '\0';
       return (input_buffer_);
 
-    } else { // new version: return value() which will be copied
+    } else { // string version: return value() which will be copied
 
       return input_->value();
     }