Add minimal version of class Fl_String

This class will be used in fl_input_str() and fl_password_str().

Todo: add missing documentation ...

3 files changed, 161 insertions, 0 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 3c00f0da9..aa74b6c7d 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -78,6 +78,7 @@ set (CPPFILES
   Fl_Single_Window.cxx
   Fl_Slider.cxx
   Fl_Spinner.cxx
+  Fl_String.cxx
   Fl_Sys_Menu_Bar.cxx
   Fl_System_Driver.cxx
   Fl_Table.cxx
diff --git a/src/Fl_String.cxx b/src/Fl_String.cxx
new file mode 100644
index 000000000..c4417523c
--- /dev/null
+++ b/src/Fl_String.cxx
@@ -0,0 +1,159 @@
+//
+// Basic Fl_String class for the Fast Light Tool Kit (FLTK).
+//
+// Copyright 2021 by Bill Spitzak and others.
+//
+// This library is free software. Distribution and use rights are outlined in
+// the file "COPYING" which should have been included with this file.  If this
+// file is missing or damaged, see the license at:
+//
+//     https://www.fltk.org/COPYING.php
+//
+// Please see the following page on how to report bugs and issues:
+//
+//     https://www.fltk.org/bugs.php
+//
+
+#include <FL/Fl_String.H>
+
+#include <stdio.h>
+#include <string.h>
+
+/** \file src/Fl_String.cxx
+  Basic Fl_String class for FLTK.
+*/
+
+static int string_count;
+
+Fl_String::Fl_String() {
+  string_count++;
+  init();
+  // debug("created ()");
+}
+
+Fl_String::Fl_String(const char *str) {
+  string_count++;
+  init();
+  value(str);
+  // debug("created (str)");
+}
+
+Fl_String::Fl_String(const char *str, int size) {
+  string_count++;
+  init();
+  value(str, size);
+  // debug("created (str, size)");
+}
+
+void Fl_String::init() {
+  size_ = 0;
+  value_ = 0;
+  capacity_ = 0;
+}
+
+// copy constructor
+Fl_String::Fl_String(const Fl_String &in) {
+  string_count++;
+  init();
+  value(in.value(), in.size());
+  // debug("copied (c'tor)");
+}
+
+// copy assignment operator
+Fl_String& Fl_String::operator=(const Fl_String &in) {
+  if (this == &in)
+    return *this;
+  value(in.value(), in.size());
+  // debug("copy assigned");
+  return *this;
+}
+
+// assignment operator for 'const char *'
+Fl_String& Fl_String::operator=(const char *in) {
+  value(in);
+  // debug("*STRING* assigned");
+  return *this;
+}
+
+Fl_String::~Fl_String() {
+  string_count--;
+  // debug("~Fl_String()");
+  delete[] value_;
+}
+
+void Fl_String::alloc_buf(int size) {
+  if (size < 0)
+    return;
+  if (size > 0 && size <= capacity_)
+    return;
+  if (capacity_ > 0)
+    return;
+
+  int new_size = (size + 1 + 15) & (~15); // round upwards
+  char *new_value = new char[new_size];
+  capacity_ = new_size - 1;
+
+  size_ = 0;
+  delete[] value_;
+  value_ = new_value;
+}
+
+void Fl_String::value(const char *str) {
+  value(str, str ? strlen(str) : 0);
+}
+
+int Fl_String::slen() const {
+  if (!value_) return 0;
+  return (int)strlen(value_);
+}
+
+void Fl_String::value(const char *str, int len) {
+  if (str) {
+    alloc_buf(len);
+    size_ = len;
+    memcpy(value_, str, size_);
+    value_[size_] = '\0';
+  } else {            // str == NULL
+    size_ = 0;        // ignore len !
+    delete[] value_;  // free buffer
+    value_ = NULL;    // set null pointer (!)
+    capacity_ = 0;    // reset capacity
+  }
+}
+
+int Fl_String::capacity() const {
+  return capacity_; // > 0 ? capacity_ - 1 : capacity_;
+}
+
+void Fl_String::release() {
+  delete[] value_;
+  value_ = 0;
+  size_ = 0;
+  capacity_ = 0;
+}
+
+// =============================  DEBUG  =============================
+
+static const char fl_string_debug = 0;
+
+void Fl_String::debug(const char *info) const {
+  if (fl_string_debug) {
+    printf("Fl_String[%2d] '%-20s': %p, value = %p (%d/%d): '%s'.\n",
+          string_count, info, this, value_, size_, capacity_, value_);
+  }
+}
+
+void Fl_String::hexdump(const char *info) const {
+  if (fl_string_debug) {
+    debug(info);
+    for (int i = 0; i < size_; i++) {
+      if ((i & 15) == 0) {
+        if (i > 0) printf("\n");
+        printf("  [%04x %4d] ", i, i);
+      } else if ((i & 3) == 0)
+        printf(" ");
+      printf(" %02x", (unsigned char)value_[i]);
+    }
+    printf("\n");
+  }
+}
diff --git a/src/Makefile b/src/Makefile
index 0d27e8c61..a31788929 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -80,6 +80,7 @@ CPPFILES = \
 	Fl_Single_Window.cxx \
 	Fl_Slider.cxx \
 	Fl_Spinner.cxx \
+	Fl_String.cxx \
 	Fl_Sys_Menu_Bar.cxx \
 	Fl_System_Driver.cxx \
 	Fl_Table.cxx \