dialog-fincalc.c

/********************************************************************\
 * dialog-fincalc.c : dialog for a financial calculator             *
 * Copyright (C) 2000 Dave Peticolas <dave@krondo.com>              *
 * Copyright (c) 2006 David Hampton <hampton@employees.org>         *
 *                                                                  *
 * This program is free software; you can redistribute it and/or    *
 * modify it under the terms of the GNU General Public License as   *
 * published by the Free Software Foundation; either version 2 of   *
 * the License, or (at your option) any later version.              *
 *                                                                  *
 * This program is distributed in the hope that it will be useful,  *
 * but WITHOUT ANY WARRANTY; without even the implied warranty of   *
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the    *
 * GNU General Public License for more details.                     *
 *                                                                  *
 * You should have received a copy of the GNU General Public License*
 * along with this program; if not, contact:                        *
 *                                                                  *
 * Free Software Foundation           Voice:  +1-617-542-5942       *
 * 51 Franklin Street, Fifth Floor    Fax:    +1-617-542-2652       *
 * Boston, MA  02110-1301,  USA       gnu@gnu.org                   *
\********************************************************************/

#include "config.h"

#include <gtk/gtk.h>
#include <glib/gi18n.h>
#include <locale.h>
#include <time.h>

#include "dialog-fincalc.h"
#include "dialog-utils.h"
#include "finproto.h"
#include "finvar.h"
#include "gnc-amount-edit.h"
#include "gnc-commodity.h"
#include "gnc-component-manager.h"
#include "gnc-date-edit.h"
#include "gnc-engine.h"
#include "gnc-gui-query.h"


#define DIALOG_FINCALC_CM_CLASS "dialog-fincalc"
#define GCONF_SECTION "dialogs/fincalc"

typedef enum
{
  PAYMENT_PERIODS = 0,
  INTEREST_RATE,
  PRESENT_VALUE,
  PERIODIC_PAYMENT,
  FUTURE_VALUE,
  NUM_FIN_CALC_VALUES
} FinCalcValue;


struct _FinCalcDialog
{
  GladeXML *xml;
  GtkWidget *dialog;

  GtkWidget *amounts[NUM_FIN_CALC_VALUES];

  GtkWidget *calc_button;

  GtkWidget *compounding_combo;
  GtkWidget *payment_combo;

  GtkWidget *end_of_period_radio;
  GtkWidget *discrete_compounding_radio;

  GtkWidget *payment_total_label;

  financial_info financial_info;
};

static unsigned int periods[] =
{
    1, /* annual */
    2, /* semi-annual */
    3, /* tri-annual */
    4, /* quarterly */
    6, /* bi-monthly */
   12, /* monthly */
   24, /* semi-monthly */
   26, /* bi-weekly */
   52, /* weekly */
  360, /* daily (360) */
  365, /* daily (365) */
};

/* This static indicates the debugging module that this .o belongs to.  */
static QofLogModule log_module = GNC_MOD_GUI;


void fincalc_update_calc_button_cb(GtkWidget *unused, FinCalcDialog *fcd);
void fincalc_calc_clicked_cb(GtkButton *button, FinCalcDialog *fcd);
void fincalc_compounding_radio_toggled(GtkToggleButton *togglebutton, gpointer data);
void fincalc_amount_clear_clicked_cb(GtkButton *button, GNCAmountEdit *edit);
void fincalc_response_cb (GtkDialog *dialog, gint response, FinCalcDialog *fcd);

/* Ensure the given argument is one of the values in the periods array
 * above and return the index of the value. */
static int
normalize_period(unsigned int *period)
{
  int i;

  g_return_val_if_fail (period, 0);

  for (i = (sizeof(periods) / sizeof(unsigned int)) - 1; i >= 0; i--)
    if (*period >= periods[i])
    {
      *period = periods[i];
      return i;
    }

  *period = periods[0];

  return 0;
}

/* Copy the values in the financial_info structure to the GUI */
static void
fi_to_gui(FinCalcDialog *fcd)
{
  const gnc_commodity *commodity;
  static char string[64];
  gnc_numeric total;
  gnc_numeric npp;
  gnc_numeric pmt;
  int i;

  if (fcd == NULL)
    return;

  npp = gnc_numeric_create (fcd->financial_info.npp, 1);

  gnc_amount_edit_set_amount (GNC_AMOUNT_EDIT(fcd->amounts[PAYMENT_PERIODS]),
                              npp);
  gnc_amount_edit_set_damount (GNC_AMOUNT_EDIT(fcd->amounts[INTEREST_RATE]),
                               fcd->financial_info.ir);
  gnc_amount_edit_set_damount (GNC_AMOUNT_EDIT(fcd->amounts[PRESENT_VALUE]),
                               fcd->financial_info.pv);
  gnc_amount_edit_set_damount (GNC_AMOUNT_EDIT(fcd->amounts[PERIODIC_PAYMENT]),
                               fcd->financial_info.pmt);
  gnc_amount_edit_set_damount (GNC_AMOUNT_EDIT(fcd->amounts[FUTURE_VALUE]),
                               -fcd->financial_info.fv);

  pmt = double_to_gnc_numeric (fcd->financial_info.pmt, 100000, GNC_RND_ROUND);

  commodity = gnc_default_currency ();

  total = gnc_numeric_mul (npp, pmt, gnc_commodity_get_fraction (commodity),
                           GNC_RND_ROUND);

  xaccSPrintAmount (string, total, gnc_default_print_info (FALSE));
  gtk_label_set_text (GTK_LABEL(fcd->payment_total_label), string);

  i = normalize_period(&fcd->financial_info.CF);
  gtk_combo_box_set_active(GTK_COMBO_BOX(fcd->compounding_combo), i);

  i = normalize_period(&fcd->financial_info.PF);
  gtk_combo_box_set_active(GTK_COMBO_BOX(fcd->payment_combo), i);

  gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(fcd->end_of_period_radio),
                               !fcd->financial_info.bep);

  gtk_toggle_button_set_active
    (GTK_TOGGLE_BUTTON(fcd->discrete_compounding_radio),
     fcd->financial_info.disc);
}

/* Copy the values in the GUI to the financial_info structure */
static void
gui_to_fi(FinCalcDialog *fcd)
{
  GtkToggleButton *toggle;
  gnc_numeric npp;
  int i;

  if (fcd == NULL)
    return;

  npp =
    gnc_amount_edit_get_amount(GNC_AMOUNT_EDIT(fcd->amounts[PAYMENT_PERIODS]));
  fcd->financial_info.npp = npp.num;

  fcd->financial_info.ir =
    gnc_amount_edit_get_damount(GNC_AMOUNT_EDIT(fcd->amounts[INTEREST_RATE]));

  fcd->financial_info.pv =
    gnc_amount_edit_get_damount(GNC_AMOUNT_EDIT(fcd->amounts[PRESENT_VALUE]));

  fcd->financial_info.pmt =
    gnc_amount_edit_get_damount(GNC_AMOUNT_EDIT(fcd->amounts[PERIODIC_PAYMENT]));

  fcd->financial_info.fv =
    gnc_amount_edit_get_damount(GNC_AMOUNT_EDIT(fcd->amounts[FUTURE_VALUE]));
  fcd->financial_info.fv = -fcd->financial_info.fv;

  i = gtk_combo_box_get_active(GTK_COMBO_BOX(fcd->compounding_combo));
  fcd->financial_info.CF = periods[i];

  i = gtk_combo_box_get_active(GTK_COMBO_BOX(fcd->payment_combo));
  fcd->financial_info.PF = periods[i];

  toggle = GTK_TOGGLE_BUTTON(fcd->end_of_period_radio);
  fcd->financial_info.bep = !gtk_toggle_button_get_active(toggle);

  toggle = GTK_TOGGLE_BUTTON(fcd->discrete_compounding_radio);
  fcd->financial_info.disc = gtk_toggle_button_get_active(toggle);

  fcd->financial_info.prec = gnc_locale_decimal_places ();
}

/* Set the sensitivity of the calculation buttons based on the argument. */
void
fincalc_update_calc_button_cb(GtkWidget *unused, FinCalcDialog *fcd)
{
  const gchar *text;
  gint i;

  if (fcd == NULL)
    return;

  for (i = 0; i < NUM_FIN_CALC_VALUES; i++) {
    text = gtk_entry_get_text(GTK_ENTRY(fcd->amounts[i]));
    if ((text == NULL) || (*text == '\0')) {
      gtk_widget_set_sensitive(GTK_WIDGET(fcd->calc_button), TRUE);
      return;
    }
  }

  gtk_widget_set_sensitive(GTK_WIDGET(fcd->calc_button), FALSE);
}

/* Free the calc button list and free the FinCalcDialog structure. */
static void
fincalc_dialog_destroy(GtkObject *object, gpointer data)
{
  FinCalcDialog *fcd = data;

  if (fcd == NULL)
    return;

  gnc_unregister_gui_component_by_data (DIALOG_FINCALC_CM_CLASS, fcd);

  g_object_unref(fcd->xml);
  g_free(fcd);
}

void
fincalc_compounding_radio_toggled(GtkToggleButton *togglebutton, gpointer data)
{
  FinCalcDialog *fcd = data;
  gboolean sensitive;

  if (fcd == NULL)
    return;

  fincalc_update_calc_button_cb(GTK_WIDGET(togglebutton), fcd);

  sensitive = gtk_toggle_button_get_active (togglebutton);

  gtk_widget_set_sensitive (fcd->compounding_combo, sensitive);
}

void
fincalc_amount_clear_clicked_cb(GtkButton *button, GNCAmountEdit *edit)
{
  gtk_entry_set_text(GTK_ENTRY (edit), "");
}

static void
init_fi(FinCalcDialog *fcd)
{
  struct lconv *lc;

  if (fcd == NULL)
    return;

  lc = gnc_localeconv();

  fcd->financial_info.npp = 12;
  fcd->financial_info.ir = 8.5;
  fcd->financial_info.pv = 15000.0;
  fcd->financial_info.pmt = -400.0;
  fcd->financial_info.CF = 12;
  fcd->financial_info.PF = 12;
  fcd->financial_info.bep = FALSE;
  fcd->financial_info.disc = TRUE;
  fcd->financial_info.prec = lc->frac_digits;

  fi_calc_future_value(&fcd->financial_info);
}

/* Determine whether the value can be calculated. If it can, return
 * NULL. Otherwise, return a string describing the reason and the offending
 * entry in error_item. */
static const char *
can_calc_value(FinCalcDialog *fcd, FinCalcValue value, int *error_item)
{
  const char *missing = _("This program can only calculate one value at a time. "
                          "You must enter values for all but one quantity.");
  const char *bad_exp = _("GnuCash cannot determine the value in one of the fields. "
                          "You must enter a valid expression.");
  const char *string;
  gnc_numeric nvalue;
  unsigned int i;

  if (fcd == NULL)
    return NULL;

  /* Check for missing values */
  for (i = 0; i < NUM_FIN_CALC_VALUES; i++)
    if (i != value)
    {
      string = gtk_entry_get_text(GTK_ENTRY(fcd->amounts[i]));
      if ((string == NULL) || (*string == '\0'))
      {
        *error_item = i;
        return missing;
      }

      if (!gnc_amount_edit_evaluate (GNC_AMOUNT_EDIT (fcd->amounts[i])))
      {
        *error_item = i;
        return bad_exp;
      }
    }

  /* Check for zero interest */
  switch (value)
  {
    case PAYMENT_PERIODS:
    case PRESENT_VALUE:
    case PERIODIC_PAYMENT:
    case FUTURE_VALUE:
      nvalue = gnc_amount_edit_get_amount
        (GNC_AMOUNT_EDIT (fcd->amounts[INTEREST_RATE]));
      if (gnc_numeric_zero_p (nvalue))
      {
        *error_item = INTEREST_RATE;
        return _("The interest rate cannot be zero.");
      }
      break;
    default:
      break;
  }

  /* Check for zero payment periods */
  switch (value)
  {
    case INTEREST_RATE:
    case PRESENT_VALUE:
    case PERIODIC_PAYMENT:
    case FUTURE_VALUE:
      nvalue = gnc_amount_edit_get_amount
        (GNC_AMOUNT_EDIT(fcd->amounts[PAYMENT_PERIODS]));
      if (gnc_numeric_zero_p (nvalue))
      {
        *error_item = PAYMENT_PERIODS;
        return _("The number of payments cannot be zero.");
      }
      if (gnc_numeric_negative_p (nvalue))
      {
        *error_item = PAYMENT_PERIODS;
        return _("The number of payments cannot be negative.");
      }
      break;
    default:
      break;
  }

  return NULL;
}

static void
calc_value(FinCalcDialog *fcd, FinCalcValue value)
{
  const char *string;
  int error_item = 0;

  if (fcd == NULL)
    return;

  string = can_calc_value(fcd, value, &error_item);
  if (string != NULL)
  {
    GtkWidget *entry;

    gnc_error_dialog(fcd->dialog, "%s", string);
    if (error_item == 0)
      entry = fcd->amounts[0];
    else
      entry = fcd->amounts[error_item];
    gtk_widget_grab_focus (entry);
    return;
  }

  gui_to_fi(fcd);

  switch (value)
  {
    case PAYMENT_PERIODS:
      fi_calc_num_payments(&fcd->financial_info);
      break;
    case INTEREST_RATE:
      fi_calc_interest(&fcd->financial_info);
      break;
    case PRESENT_VALUE:
      fi_calc_present_value(&fcd->financial_info);
      break;
    case PERIODIC_PAYMENT:
      fi_calc_payment(&fcd->financial_info);
      break;
    case FUTURE_VALUE:
      fi_calc_future_value(&fcd->financial_info);
      break;
    default:
      PERR("Unknown financial variable");
      break;
  }

  fi_to_gui(fcd);

  gtk_widget_set_sensitive(GTK_WIDGET(fcd->calc_button), FALSE);
}

void
fincalc_calc_clicked_cb(GtkButton *button, FinCalcDialog *fcd)
{
  const gchar *text;
  gint i;

  for (i = 0; i < NUM_FIN_CALC_VALUES; i++) {
    text = gtk_entry_get_text(GTK_ENTRY(fcd->amounts[i]));
    if ((text != NULL) && (*text != '\0'))
      continue;
    calc_value(fcd, i);
    return;
  }
}

void fincalc_response_cb (GtkDialog *dialog,
                          gint response,
                          FinCalcDialog *fcd)
{
  switch (response) {
    case GTK_RESPONSE_OK:
      /* Do something here whenever the hidden schedule button is clicked. */
      /* Fall through */

    case GTK_RESPONSE_CLOSE:
      gnc_save_window_size(GCONF_SECTION, GTK_WINDOW(dialog));
      break;

    default:
      /* Cancel, destroy, etc.  Do nothing. */
      break;
  }

  gnc_close_gui_component_by_data (DIALOG_FINCALC_CM_CLASS, fcd);
}


static void
close_handler (gpointer user_data)
{
  FinCalcDialog *fcd = user_data;

  gtk_widget_destroy (fcd->dialog);
}

static gboolean
show_handler (const char *class, gint component_id,
              gpointer user_data, gpointer iter_data)
{
  FinCalcDialog *fcd = user_data;

  if (!fcd)
    return(FALSE);
  gtk_window_present (GTK_WINDOW(fcd->dialog));
  return(TRUE);
}


static void
fincalc_init_gae (GNCAmountEdit *edit,
                  gint min_places,
                  gint max_places,
                  gint fraction)
{
  GNCPrintAmountInfo print_info;

  print_info = gnc_integral_print_info ();
  print_info.min_decimal_places = min_places;
  print_info.max_decimal_places = max_places;

  gnc_amount_edit_set_print_info (edit, print_info);
  gnc_amount_edit_set_fraction (edit, fraction);
  gnc_amount_edit_set_evaluate_on_enter (edit, TRUE);
  gtk_entry_set_alignment (GTK_ENTRY(edit), 1.0);
}

static void
fincalc_init_commodity_gae (GNCAmountEdit *edit)
{
  GNCPrintAmountInfo print_info;
  gnc_commodity *commodity;
  gint fraction;

  commodity = gnc_default_currency();
  fraction = gnc_commodity_get_fraction(commodity);
  print_info = gnc_commodity_print_info (commodity, FALSE);

  gnc_amount_edit_set_print_info (edit, print_info);
  gnc_amount_edit_set_fraction (edit, fraction);
  gnc_amount_edit_set_evaluate_on_enter (edit, TRUE);
  gtk_entry_set_alignment (GTK_ENTRY(edit), 1.0);
}

void
gnc_ui_fincalc_dialog_create(void)
{
  FinCalcDialog *fcd;
  GtkWidget *button;
  GtkWidget *combo;
  GtkWidget *edit;
  GladeXML  *xml;

  if (gnc_forall_gui_components (DIALOG_FINCALC_CM_CLASS,
                                 show_handler, NULL))
      return;


  fcd = g_new0(FinCalcDialog, 1);

  xml = gnc_glade_xml_new ("fincalc.glade", "Financial Calculator Dialog");

  fcd->xml = xml;
  fcd->dialog = glade_xml_get_widget (xml, "Financial Calculator Dialog");

  gnc_register_gui_component (DIALOG_FINCALC_CM_CLASS,
                              NULL, close_handler, fcd);

  g_signal_connect (G_OBJECT (fcd->dialog), "destroy",
                    G_CALLBACK (fincalc_dialog_destroy), fcd);


  edit = glade_xml_get_widget (xml, "payment_periods_edit");
  fincalc_init_gae (GNC_AMOUNT_EDIT (edit), 0, 0, 1);
  fcd->amounts[PAYMENT_PERIODS] = edit;

  edit = glade_xml_get_widget (xml, "interest_rate_edit");
  fincalc_init_gae (GNC_AMOUNT_EDIT (edit), 2, 5, 100000);
  fcd->amounts[INTEREST_RATE] = edit;

  edit = glade_xml_get_widget (xml, "present_value_edit");
  fincalc_init_commodity_gae (GNC_AMOUNT_EDIT (edit));
  fcd->amounts[PRESENT_VALUE] = edit;

  edit = glade_xml_get_widget (xml, "period_payment_edit");
  fincalc_init_commodity_gae (GNC_AMOUNT_EDIT (edit));
  fcd->amounts[PERIODIC_PAYMENT] = edit;

  edit = glade_xml_get_widget (xml, "future_value_edit");
  fincalc_init_commodity_gae (GNC_AMOUNT_EDIT (edit));
  fcd->amounts[FUTURE_VALUE] = edit;


  fcd->calc_button = glade_xml_get_widget (xml, "calc_button");


  combo = glade_xml_get_widget (xml, "compounding_combo");
  fcd->compounding_combo = combo;
  g_signal_connect(fcd->compounding_combo, "changed",
                   G_CALLBACK (fincalc_update_calc_button_cb), fcd);

  combo = glade_xml_get_widget (xml, "payment_combo");
  fcd->payment_combo = combo;
  g_signal_connect(fcd->compounding_combo, "changed",
                   G_CALLBACK (fincalc_update_calc_button_cb), fcd);

  button = glade_xml_get_widget (xml, "period_payment_radio");
  fcd->end_of_period_radio = button;

  button = glade_xml_get_widget (xml, "discrete_compounding_radio");
  fcd->discrete_compounding_radio = button;

  fcd->payment_total_label = glade_xml_get_widget (xml, "payment_total_label");

  button = glade_xml_get_widget (xml, "schedule_button");
  gtk_widget_hide (button);

  init_fi(fcd);

  fi_to_gui(fcd);

  gtk_widget_grab_focus(fcd->amounts[PAYMENT_PERIODS]);

  /* Connect all signals specified in glade. */
  glade_xml_signal_autoconnect_full( xml,
                                     gnc_glade_autoconnect_full_func,
                                     fcd);

  gnc_restore_window_size(GCONF_SECTION, GTK_WINDOW(fcd->dialog));
  gtk_widget_show(fcd->dialog);
}

void
gnc_ui_fincalc_dialog_destroy(FinCalcDialog *fcd)
{
  if (fcd == NULL)
    return;

  gnc_close_gui_component_by_data (DIALOG_FINCALC_CM_CLASS, fcd);
}

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