/*
 * Copyright (C) 2008-2011 Robert Ancell
 *
 * 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. See http://www.gnu.org/copyleft/gpl.html the full text of the
 * license.
 */

#include <glib/gi18n.h>

#include "math-buttons.h"
#include "math-converter.h"
#include "math-variable-popup.h"
#include "financial.h"
#include "mp-serializer.h"
#include "utility.h"

enum {
    PROP_0,
    PROP_EQUATION,
    PROP_MODE,
    PROP_PROGRAMMING_BASE
};

static GType button_mode_type;

#define MAXBITS 64      /* Bit panel: number of bit fields. */

struct MathButtonsPrivate
{
    MathEquation *equation;

    ButtonMode mode;
    gint programming_base;

    MathConverter *converter;

    GtkBuilder *basic_ui, *advanced_ui, *financial_ui, *programming_ui;

    GtkWidget *bas_panel, *adv_panel, *fin_panel, *prog_panel;
    GtkWidget *active_panel;

    GtkWidget *shift_left_menu, *shift_right_menu;

    GtkWidget *function_menu;
    GtkWidget *const_menu;

    GList *superscript_toggles;
    GList *subscript_toggles;

    GtkWidget *base_combo;
    GtkWidget *base_label;
    GtkWidget *bit_panel;
    GtkWidget *bit_labels[MAXBITS];

    GtkWidget *character_code_dialog;
    GtkWidget *character_code_entry;
};

G_DEFINE_TYPE_WITH_PRIVATE (MathButtons, math_buttons, GTK_TYPE_BOX);

#define UI_BASIC_RESOURCE_PATH       "/org/mate/calculator/ui/buttons-basic.ui"
#define UI_ADVANCED_RESOURCE_PATH    "/org/mate/calculator/ui/buttons-advanced.ui"
#define UI_FINANCIAL_RESOURCE_PATH   "/org/mate/calculator/ui/buttons-financial.ui"
#define UI_PROGRAMMING_RESOURCE_PATH "/org/mate/calculator/ui/buttons-programming.ui"

#define GET_WIDGET(ui, name) \
          GTK_WIDGET(gtk_builder_get_object((ui), (name)))

#define WM_WIDTH_FACTOR  10
#define WM_HEIGHT_FACTOR 30

typedef enum
{
    NUMBER,
    NUMBER_BOLD,
    OPERATOR,
    FUNCTION,
    MEMORY,
    GROUP,
    ACTION
} ButtonClass;

typedef struct {
    const char *widget_name;
    const char *data;
    ButtonClass class;
    const char *tooltip;
} ButtonData;

static ButtonData button_data[] = {
    {"pi",                 "π", NUMBER,
      /* Tooltip for the Pi button */
      N_("Pi [Ctrl+P]")},
    {"eulers_number",      "e", NUMBER,
      /* Tooltip for the Euler's Number button */
      N_("Euler’s Number")},
    {"imaginary",          "i", NUMBER, NULL},
    {"numeric_point", NULL, NUMBER, NULL},
    {"subscript", NULL, NUMBER_BOLD,
      /* Tooltip for the subscript button */
      N_("Subscript mode [Alt]")},
    {"superscript", NULL, NUMBER_BOLD,
      /* Tooltip for the superscript button */
      N_("Superscript mode [Ctrl]")},
    {"exponential", NULL, NUMBER_BOLD,
      /* Tooltip for the scientific exponent button */
      N_("Scientific exponent [Ctrl+E]")},
    {"add",                "+", OPERATOR,
      /* Tooltip for the add button */
      N_("Add [+]")},
    {"subtract",           "−", OPERATOR,
      /* Tooltip for the subtract button */
      N_("Subtract [-]")},
    {"multiply",           "×", OPERATOR,
      /* Tooltip for the multiply button */
      N_("Multiply [*]")},
    {"divide",             "÷", OPERATOR,
      /* Tooltip for the divide button */
      N_("Divide [/]")},
    {"modulus_divide",     " mod ", OPERATOR,
      /* Tooltip for the modulus divide button */
      N_("Modulus divide")},
    {"function",           NULL, FUNCTION,
      /* Tooltip for the additional functions button */
      N_("Additional Functions")},
    {"const",           NULL, FUNCTION,
      /* Tooltip for the additional constant button */
      N_("Additional constants")},
    {"x_pow_y",            "^", FUNCTION,
      /* Tooltip for the exponent button */
      N_("Exponent [^ or **]")},
    {"x_squared",          "²", FUNCTION,
      /* Tooltip for the square button */
      N_("Square [Ctrl+2]")},
    {"percentage",         "%", NUMBER,
      /* Tooltip for the percentage button */
      N_("Percentage [%]")},
    {"factorial",          "!", FUNCTION,
      /* Tooltip for the factorial button */
      N_("Factorial [!]")},
    {"abs",                "|", FUNCTION,
      /* Tooltip for the absolute value button */
      N_("Absolute value [|]")},
    {"arg",                "Arg ", FUNCTION,
      /* Tooltip for the complex argument component button */
      N_("Complex argument")},
    {"conjugate",          "conj ", FUNCTION,
      /* Tooltip for the complex conjugate button */
      N_("Complex conjugate")},
    {"root",               "√", FUNCTION,
      /* Tooltip for the root button */
      N_("Root [Ctrl+R]")},
    {"square_root",        "√", FUNCTION,
      /* Tooltip for the square root button */
      N_("Square root [Ctrl+R]")},
    {"logarithm",          "log ", FUNCTION,
      /* Tooltip for the logarithm button */
      N_("Logarithm")},
    {"natural_logarithm",  "ln ", FUNCTION,
      /* Tooltip for the natural logarithm button */
      N_("Natural Logarithm")},
    {"sine",               "sin ", FUNCTION,
      /* Tooltip for the sine button */
      N_("Sine")},
    {"cosine",             "cos ", FUNCTION,
      /* Tooltip for the cosine button */
      N_("Cosine")},
    {"tangent",            "tan ", FUNCTION,
      /* Tooltip for the tangent button */
      N_("Tangent")},
    {"hyperbolic_sine",    "sinh ", FUNCTION,
      /* Tooltip for the hyperbolic sine button */
      N_("Hyperbolic Sine")},
    {"hyperbolic_cosine",  "cosh ", FUNCTION,
      /* Tooltip for the hyperbolic cosine button */
      N_("Hyperbolic Cosine")},
    {"hyperbolic_tangent", "tanh ", FUNCTION,
      /* Tooltip for the hyperbolic tangent button */
      N_("Hyperbolic Tangent")},
    {"inverse_sine", "asin", FUNCTION,
      /* Tooltip for the inverse sine button */
      N_("Inverse Sine")},
    {"inverse_cosine", "acos", FUNCTION,
      /* Tooltip for the inverse cosine button */
      N_("Inverse Cosine")},
    {"inverse_tangent", "atan", FUNCTION,
      /* Tooltip for the inverse tangent button */
      N_("Inverse Tangent")},
    {"inverse",            "⁻¹", FUNCTION,
      /* Tooltip for the inverse button */
      N_("Inverse [Ctrl+I]")},
    {"and",                "∧", OPERATOR,
      /* Tooltip for the boolean AND button */
      N_("Boolean AND")},
    {"or",                 "∨", OPERATOR,
      /* Tooltip for the boolean OR button */
      N_("Boolean OR")},
    {"xor",                "⊻", OPERATOR,
      /* Tooltip for the exclusive OR button */
      N_("Boolean Exclusive OR")},
    {"not",                "¬", FUNCTION,
      /* Tooltip for the boolean NOT button */
      N_("Boolean NOT")},
    {"integer_portion",    "int ", FUNCTION,
      /* Tooltip for the integer component button */
      N_("Integer Component")},
    {"fractional_portion", "frac ", FUNCTION,
      /* Tooltip for the fractional component button */
      N_("Fractional Component")},
    {"real_portion",       "Re ", FUNCTION,
      /* Tooltip for the real component button */
      N_("Real Component")},
    {"imaginary_portion",  "Im ", FUNCTION,
      /* Tooltip for the imaginary component button */
      N_("Imaginary Component")},
    {"ones_complement",    "ones ", FUNCTION,
      /* Tooltip for the ones' complement button */
      N_("Ones' Complement")},
    {"twos_complement",    "twos ", FUNCTION,
      /* Tooltip for the two's complement button */
      N_("Two's Complement")},
    {"trunc",              "trunc ", FUNCTION,
      /* Tooltip for the truncate button */
      N_("Truncate")},
    {"start_group",        "(", GROUP,
      /* Tooltip for the start group button */
      N_("Start Group [(]")},
    {"end_group",          ")", GROUP,
      /* Tooltip for the end group button */
      N_("End Group [)]")},
    {"memory", NULL, MEMORY,
      /* Tooltip for the memory button */
      N_("Memory")},
    {"character", NULL, MEMORY,
      /* Tooltip for the insert character code button */
      N_("Insert Character Code")},
    {"result", NULL, ACTION,
      /* Tooltip for the solve button */
      N_("Calculate Result")},
    {"factor", NULL, ACTION,
      /* Tooltip for the factor button */
      N_("Factorize [Ctrl+F]")},
    {"clear", NULL, GROUP,
      /* Tooltip for the clear button */
      N_("Clear Display [Escape]")},
    {"undo", NULL, GROUP,
      /* Tooltip for the undo button */
      N_("Undo [Ctrl+Z]")},
    {"shift_left", NULL, ACTION,
      /* Tooltip for the shift left button */
      N_("Shift Left [<<]")},
    {"shift_right", NULL, ACTION,
      /* Tooltip for the shift right button */
      N_("Shift Right [>>]")},
    {"finc_compounding_term", NULL, FUNCTION,
      /* Tooltip for the compounding term button */
      N_("Compounding Term")},
    {"finc_double_declining_depreciation", NULL, FUNCTION,
      /* Tooltip for the double declining depreciation button */
      N_("Double Declining Depreciation")},
    {"finc_future_value", NULL, FUNCTION,
      /* Tooltip for the future value button */
      N_("Future Value")},
    {"finc_term", NULL, FUNCTION,
      /* Tooltip for the financial term button */
      N_("Financial Term")},
    {"finc_sum_of_the_years_digits_depreciation", NULL, FUNCTION,
      /* Tooltip for the sum of the years digits depreciation button */
      N_("Sum of the Years Digits Depreciation")},
    {"finc_straight_line_depreciation", NULL, FUNCTION,
      /* Tooltip for the straight line depreciation button */
      N_("Straight Line Depreciation")},
    {"finc_periodic_interest_rate", NULL, FUNCTION,
      /* Tooltip for the periodic interest rate button */
      N_("Periodic Interest Rate")},
    {"finc_present_value", NULL, FUNCTION,
      /* Tooltip for the present value button */
      N_("Present Value")},
    {"finc_periodic_payment", NULL, FUNCTION,
      /* Tooltip for the periodic payment button */
      N_("Periodic Payment")},
    {"finc_gross_profit_margin", NULL, FUNCTION,
      /* Tooltip for the gross profit margin button */
      N_("Gross Profit Margin")},
    {NULL, NULL, 0, NULL}
};

/* The names of each field in the dialogs for the financial functions */
static char *finc_dialog_fields[][5] = {
    {"ctrm_pint", "ctrm_fv",     "ctrm_pv",    NULL,         NULL},
    {"ddb_cost",  "ddb_life",    "ddb_period", NULL,         NULL},
    {"fv_pmt",    "fv_pint",     "fv_n",       NULL,         NULL},
    {"gpm_cost",  "gpm_margin",  NULL,         NULL,         NULL},
    {"pmt_prin",  "pmt_pint",    "pmt_n",      NULL,         NULL},
    {"pv_pmt",    "pv_pint",     "pv_n",       NULL,         NULL},
    {"rate_fv",   "rate_pv",     "rate_n",     NULL,         NULL},
    {"sln_cost",  "sln_salvage", "sln_life",   NULL,         NULL},
    {"syd_cost",  "syd_salvage", "syd_life",   "syd_period", NULL},
    {"term_pmt",  "term_fv",     "term_pint",  NULL,         NULL},
    {NULL,        NULL,          NULL,         NULL,         NULL}
};


MathButtons *
math_buttons_new(MathEquation *equation)
{
    return g_object_new(math_buttons_get_type(), "equation", equation, NULL);
}

static void
set_data(GtkBuilder *ui, const gchar *object_name, const gchar *name, const char *value)
{
    GObject *object;
    object = gtk_builder_get_object(ui, object_name);
    if (object)
        g_object_set_data(object, name, GINT_TO_POINTER(value));
}


static void
set_int_data(GtkBuilder *ui, const gchar *object_name, const gchar *name, gint value)
{
    GObject *object;
    object = gtk_builder_get_object(ui, object_name);
    if (object)
        g_object_set_data(object, name, GINT_TO_POINTER(value));
}


static void
load_finc_dialogs(MathButtons *buttons)
{
    int i, j;

    set_int_data(buttons->priv->financial_ui, "ctrm_dialog", "finc_dialog", FINC_CTRM_DIALOG);
    set_int_data(buttons->priv->financial_ui, "ddb_dialog", "finc_dialog", FINC_DDB_DIALOG);
    set_int_data(buttons->priv->financial_ui, "fv_dialog", "finc_dialog", FINC_FV_DIALOG);
    set_int_data(buttons->priv->financial_ui, "gpm_dialog", "finc_dialog", FINC_GPM_DIALOG);
    set_int_data(buttons->priv->financial_ui, "pmt_dialog", "finc_dialog", FINC_PMT_DIALOG);
    set_int_data(buttons->priv->financial_ui, "pv_dialog", "finc_dialog", FINC_PV_DIALOG);
    set_int_data(buttons->priv->financial_ui, "rate_dialog", "finc_dialog", FINC_RATE_DIALOG);
    set_int_data(buttons->priv->financial_ui, "sln_dialog", "finc_dialog", FINC_SLN_DIALOG);
    set_int_data(buttons->priv->financial_ui, "syd_dialog", "finc_dialog", FINC_SYD_DIALOG);
    set_int_data(buttons->priv->financial_ui, "term_dialog", "finc_dialog", FINC_TERM_DIALOG);

    for (i = 0; finc_dialog_fields[i][0] != NULL; i++) {
        for (j = 0; finc_dialog_fields[i][j]; j++) {
            GObject *o;
            o = gtk_builder_get_object (buttons->priv->financial_ui, finc_dialog_fields[i][j]);
            g_object_set_data(o, "finc_field", GINT_TO_POINTER(j));
            g_object_set_data(o, "finc_dialog", GINT_TO_POINTER(i));
        }
    }
}


static void
update_bit_panel(MathButtons *buttons)
{
    MPNumber x;
    gboolean enabled;
    guint64 bits;
    int i;
    GString *label;
    gint base;

    if (!buttons->priv->bit_panel)
        return;

    enabled = math_equation_get_number(buttons->priv->equation, &x);

    if (enabled) {
        MPNumber max, fraction;

        mp_set_from_unsigned_integer(G_MAXUINT64, &max);
        mp_fractional_part(&x, &fraction);
        if (mp_is_negative(&x) || mp_is_greater_than(&x, &max) || !mp_is_zero(&fraction))
            enabled = FALSE;
        else
            bits = mp_cast_to_unsigned_int(&x);
    }

    gtk_widget_set_sensitive(buttons->priv->bit_panel, enabled);
    gtk_widget_set_sensitive(buttons->priv->base_label, enabled);

    if (!enabled)
        return;

    for (i = 0; i < MAXBITS; i++) {
        const gchar *label;

        if (bits & (1LLU << (MAXBITS-i-1)))
            label = " 1";
        else
            label = " 0";
        gtk_label_set_text(GTK_LABEL(buttons->priv->bit_labels[i]), label);
    }

    base = math_equation_get_base(buttons->priv->equation);
    label = g_string_new("");
    if (base != 8) {
        if (label->len != 0)
            g_string_append(label, " = ");
        g_string_append_printf(label, "%" G_GINT64_MODIFIER "o", bits);
        g_string_append(label, "₈");
    }
    if (base != 10) {
        if (label->len != 0)
            g_string_append(label, " = ");
        g_string_append_printf(label, "%" G_GINT64_MODIFIER "u", bits);
        g_string_append(label, "₁₀");
    }
    if (base != 16) {
        if (label->len != 0)
            g_string_append(label, " = ");
        g_string_append_printf(label, "%" G_GINT64_MODIFIER "X", bits);
        g_string_append(label, "₁₆");
    }

    gtk_label_set_text(GTK_LABEL(buttons->priv->base_label), label->str);
    g_string_free(label, TRUE);
}


static void
display_changed_cb(MathEquation *equation, GParamSpec *spec, MathButtons *buttons)
{
    update_bit_panel(buttons);
}


static void
base_combobox_changed_cb(GtkWidget *combo, MathButtons *buttons)
{
    gint value;
    GtkTreeModel *model;
    GtkTreeIter iter;

    model = gtk_combo_box_get_model(GTK_COMBO_BOX(combo));
    gtk_combo_box_get_active_iter(GTK_COMBO_BOX(combo), &iter);
    gtk_tree_model_get(model, &iter, 1, &value, -1);

    math_buttons_set_programming_base(buttons, value);
}


static void
base_changed_cb(MathEquation *equation, GParamSpec *spec, MathButtons *buttons)
{
    GtkTreeModel *model;
    GtkTreeIter iter;
    gboolean valid;

    if (buttons->priv->mode != PROGRAMMING)
        return;

    model = gtk_combo_box_get_model(GTK_COMBO_BOX(buttons->priv->base_combo));
    valid = gtk_tree_model_get_iter_first(model, &iter);
    buttons->priv->programming_base = math_equation_get_base(buttons->priv->equation);

    while (valid) {
        gint v;

        gtk_tree_model_get(model, &iter, 1, &v, -1);
        if (v == buttons->priv->programming_base)
            break;
        valid = gtk_tree_model_iter_next(model, &iter);
    }
    if (!valid)
        valid = gtk_tree_model_get_iter_first(model, &iter);

    gtk_combo_box_set_active_iter(GTK_COMBO_BOX(buttons->priv->base_combo), &iter);
}


static GtkWidget *
load_mode(MathButtons *buttons, ButtonMode mode)
{
    GtkBuilder *builder, **builder_ptr;
    gint i;
    gchar *name;
    const gchar *path;
    static gchar *objects[] = { "button_panel", "character_code_dialog", "currency_dialog",
                                "ctrm_dialog", "ddb_dialog", "fv_dialog", "gpm_dialog",
                                "pmt_dialog", "pv_dialog", "rate_dialog", "sln_dialog",
                                "syd_dialog", "term_dialog", "adjustment1", "adjustment2", NULL };
    GtkWidget *widget, **panel;
    GError *error = NULL;

    switch (mode) {
    default:
    case BASIC:
        builder_ptr = &buttons->priv->basic_ui;
        path = UI_BASIC_RESOURCE_PATH;
        panel = &buttons->priv->bas_panel;
        break;
    case ADVANCED:
        builder_ptr = &buttons->priv->advanced_ui;
        path = UI_ADVANCED_RESOURCE_PATH;
        panel = &buttons->priv->adv_panel;
        break;
    case FINANCIAL:
        builder_ptr = &buttons->priv->financial_ui;
        path = UI_FINANCIAL_RESOURCE_PATH;
        panel = &buttons->priv->fin_panel;
        break;
    case PROGRAMMING:
        builder_ptr = &buttons->priv->programming_ui;
        path = UI_PROGRAMMING_RESOURCE_PATH;
        panel = &buttons->priv->prog_panel;
        break;
    }

    if (*panel)
        goto out;

    builder = *builder_ptr = gtk_builder_new();
    // FIXME: Show dialog if failed to load
    gtk_builder_add_objects_from_resource(builder, path, objects, &error);
    if (error) {
        g_warning("Error loading button UI: %s", error->message);
        g_clear_error(&error);
    }
    *panel = GET_WIDGET(builder, "button_panel");
    gtk_box_pack_end(GTK_BOX(buttons), *panel, TRUE, TRUE, 0);

    /* Configure buttons */
    for (i = 0; button_data[i].widget_name != NULL; i++) {
        GObject *object;
        GtkWidget *button;

        name = g_strdup_printf("calc_%s_button", button_data[i].widget_name);
        object = gtk_builder_get_object(*builder_ptr, name);
        g_free(name);

        if (!object)
            continue;
        button = GTK_WIDGET(object);
        if (button_data[i].data)
            g_object_set_data(object, "calc_text", (gpointer) button_data[i].data);

        if (button_data[i].tooltip)
            gtk_widget_set_tooltip_text(button, _(button_data[i].tooltip));

        atk_object_set_name(gtk_widget_get_accessible(button), button_data[i].widget_name);
    }

    /* Set special button data */
    for (i = 0; i < 16; i++) {
        GtkWidget *button;

        name = g_strdup_printf("calc_%d_button", i);
        button = GET_WIDGET(builder, name);
        if (button) {
            gchar buffer[7];
            gint len;

            g_object_set_data(G_OBJECT(button), "calc_digit", GINT_TO_POINTER(i));
            len = g_unichar_to_utf8(math_equation_get_digit_text(buttons->priv->equation, i), buffer);
            buffer[len] = '\0';
            gtk_button_set_label(GTK_BUTTON(button), buffer);
        }
        g_free(name);
    }
    widget = GET_WIDGET(builder, "calc_numeric_point_button");
    if (widget) {
        MpSerializer *serializer = math_equation_get_serializer(buttons->priv->equation);
        gchar buffer[7];
        gint len;
        len = g_unichar_to_utf8(mp_serializer_get_radix(serializer), buffer);
        buffer[len] = '\0';
        gtk_button_set_label(GTK_BUTTON(widget), buffer);
    }

    widget = GET_WIDGET(builder, "calc_superscript_button");
    if (widget) {
        buttons->priv->superscript_toggles = g_list_append(buttons->priv->superscript_toggles, widget);
        if (math_equation_get_number_mode(buttons->priv->equation) == SUPERSCRIPT)
            gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(widget), TRUE);
    }
    widget = GET_WIDGET(builder, "calc_subscript_button");
    if (widget) {
        buttons->priv->subscript_toggles = g_list_append(buttons->priv->subscript_toggles, widget);
        if (math_equation_get_number_mode(buttons->priv->equation) == SUBSCRIPT)
            gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(widget), TRUE);
    }

    /* put the icon name "process-stop" in the buttons
       button1, button3, button5, button7, button9,
       button11, button13, button15, button17, button19
       taken from buttons-financial.ui */
    for (i = 1; i < 20; i++) {
        if (i % 2) {
            widget = GET_WIDGET (builder, g_strdup_printf ("button%d",i));
            if (GTK_IS_BUTTON(widget))
                gtk_button_set_image (GTK_BUTTON (widget),
                                      gtk_image_new_from_icon_name ("process-stop", GTK_ICON_SIZE_BUTTON));
        }
    }

    if (mode == PROGRAMMING) {
        GtkListStore *model;
        GtkTreeIter iter;
        GtkCellRenderer *renderer;

        buttons->priv->base_label = GET_WIDGET(builder, "base_label");
        buttons->priv->character_code_dialog = GET_WIDGET(builder, "character_code_dialog");
        buttons->priv->character_code_entry = GET_WIDGET(builder, "character_code_entry");

        buttons->priv->bit_panel = GET_WIDGET(builder, "bit_table");
        for (i = 0; i < MAXBITS; i++) {
            name = g_strdup_printf("bit_label_%d", i);
            buttons->priv->bit_labels[i] = GET_WIDGET(builder, name);
            g_free(name);
            name = g_strdup_printf("bit_eventbox_%d", i);
            set_int_data(builder, name, "bit_index", i);
        }

        buttons->priv->base_combo = GET_WIDGET(builder, "base_combo");
        model = gtk_list_store_new(2, G_TYPE_STRING, G_TYPE_INT, G_TYPE_INT);
        gtk_combo_box_set_model(GTK_COMBO_BOX(buttons->priv->base_combo), GTK_TREE_MODEL(model));
        gtk_list_store_append(GTK_LIST_STORE(model), &iter);
        gtk_list_store_set(GTK_LIST_STORE(model), &iter, 0,
                           /* Number display mode combo: Binary, e.g. 10011010010₂ */
                           _("Binary"), 1, 2, -1);
        gtk_list_store_append(GTK_LIST_STORE(model), &iter);
        gtk_list_store_set(GTK_LIST_STORE(model), &iter, 0,
                           /* Number display mode combo: Octal, e.g. 2322₈ */
                           _("Octal"), 1, 8, -1);
        gtk_list_store_append(GTK_LIST_STORE(model), &iter);
        gtk_list_store_set(GTK_LIST_STORE(model), &iter, 0,
                           /* Number display mode combo: Decimal, e.g. 1234 */
                           _("Decimal"), 1, 10, -1);
        gtk_list_store_append(GTK_LIST_STORE(model), &iter);
        gtk_list_store_set(GTK_LIST_STORE(model), &iter, 0,
                           /* Number display mode combo: Hexadecimal, e.g. 4D2₁₆ */
                           _("Hexadecimal"), 1, 16, -1);
        renderer = gtk_cell_renderer_text_new();
        gtk_cell_layout_pack_start(GTK_CELL_LAYOUT(buttons->priv->base_combo), renderer, TRUE);
        gtk_cell_layout_add_attribute(GTK_CELL_LAYOUT(buttons->priv->base_combo), renderer, "text", 0);

        g_signal_connect(buttons->priv->base_combo, "changed", G_CALLBACK(base_combobox_changed_cb), buttons);
        g_signal_connect(buttons->priv->equation, "notify::base", G_CALLBACK(base_changed_cb), buttons);
        base_changed_cb(buttons->priv->equation, NULL, buttons);
    }

    /* Setup financial functions */
    if (mode == FINANCIAL) {
        load_finc_dialogs(buttons);

        set_data(builder, "calc_finc_compounding_term_button", "finc_dialog", "ctrm_dialog");
        set_data(builder, "calc_finc_double_declining_depreciation_button", "finc_dialog", "ddb_dialog");
        set_data(builder, "calc_finc_future_value_button", "finc_dialog", "fv_dialog");
        set_data(builder, "calc_finc_gross_profit_margin_button", "finc_dialog", "gpm_dialog");
        set_data(builder, "calc_finc_periodic_payment_button", "finc_dialog", "pmt_dialog");
        set_data(builder, "calc_finc_present_value_button", "finc_dialog", "pv_dialog");
        set_data(builder, "calc_finc_periodic_interest_rate_button", "finc_dialog", "rate_dialog");
        set_data(builder, "calc_finc_straight_line_depreciation_button", "finc_dialog", "sln_dialog");
        set_data(builder, "calc_finc_sum_of_the_years_digits_depreciation_button", "finc_dialog", "syd_dialog");
        set_data(builder, "calc_finc_term_button", "finc_dialog", "term_dialog");
    }

    gtk_builder_connect_signals(builder, buttons);

    display_changed_cb(buttons->priv->equation, NULL, buttons);

out:
    return *panel;
}


static void
converter_changed_cb(MathConverter *converter, MathButtons *buttons)
{
    Unit *from_unit, *to_unit;

    math_converter_get_conversion(converter, &from_unit, &to_unit);
    if (buttons->priv->mode == FINANCIAL) {
        math_equation_set_source_currency(buttons->priv->equation, unit_get_name(from_unit));
        math_equation_set_target_currency(buttons->priv->equation, unit_get_name(to_unit));
    }
    else {
        math_equation_set_source_units(buttons->priv->equation, unit_get_name(from_unit));
        math_equation_set_target_units(buttons->priv->equation, unit_get_name(to_unit));
    }

    g_object_unref(from_unit);
    g_object_unref(to_unit);
}


static void
load_buttons(MathButtons *buttons)
{
    GtkWidget *panel;

    if (!gtk_widget_get_visible(GTK_WIDGET(buttons)))
        return;

    if (!buttons->priv->converter) {
        buttons->priv->converter = math_converter_new(buttons->priv->equation);
        g_signal_connect(buttons->priv->converter, "changed", G_CALLBACK(converter_changed_cb), buttons);
        gtk_box_pack_start(GTK_BOX(buttons), GTK_WIDGET(buttons->priv->converter), FALSE, TRUE, 0);
    }

    panel = load_mode(buttons, buttons->priv->mode);
    if (buttons->priv->active_panel == panel)
        return;

    /* Hide old buttons */
    if (buttons->priv->active_panel)
        gtk_widget_hide(buttons->priv->active_panel);

    /* Load and display new buttons */
    buttons->priv->active_panel = panel;
    if (panel)
        gtk_widget_show(panel);
}


void
math_buttons_set_mode(MathButtons *buttons, ButtonMode mode)
{
    g_return_if_fail(buttons != NULL);

    if (buttons->priv->mode == mode)
        return;

    buttons->priv->mode = mode;

    if (mode == PROGRAMMING)
        math_equation_set_base(buttons->priv->equation, buttons->priv->programming_base);
    else
        math_equation_set_base(buttons->priv->equation, 10);

    load_buttons(buttons);

    gtk_widget_set_visible(GTK_WIDGET(buttons->priv->converter), mode == ADVANCED || mode == FINANCIAL);
    if (mode == ADVANCED) {
        math_converter_set_category(buttons->priv->converter, NULL);
        math_converter_set_conversion(buttons->priv->converter,
                                      math_equation_get_source_units(buttons->priv->equation),
                                      math_equation_get_target_units(buttons->priv->equation));
    }
    else if (mode == FINANCIAL) {
        math_converter_set_category(buttons->priv->converter, "currency");
        math_converter_set_conversion(buttons->priv->converter,
                                      math_equation_get_source_currency(buttons->priv->equation),
                                      math_equation_get_target_currency(buttons->priv->equation));
    }

    g_object_notify(G_OBJECT(buttons), "mode");
}


ButtonMode
math_buttons_get_mode(MathButtons *buttons)
{
    return buttons->priv->mode;
}


void
math_buttons_set_programming_base(MathButtons *buttons, gint base)
{
    g_return_if_fail(buttons != NULL);

    if (base == buttons->priv->programming_base)
        return;

    buttons->priv->programming_base = base;

    g_settings_set_int(g_settings_var, "base", math_buttons_get_programming_base(buttons));

    if (buttons->priv->mode == PROGRAMMING)
        math_equation_set_base(buttons->priv->equation, base);
}


gint
math_buttons_get_programming_base(MathButtons *buttons)
{
    g_return_val_if_fail(buttons != NULL, 10);
    return buttons->priv->programming_base;
}


void exponent_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
exponent_cb(GtkWidget *widget, MathButtons *buttons)
{
    math_equation_insert_exponent(buttons->priv->equation);
}


void subtract_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
subtract_cb(GtkWidget *widget, MathButtons *buttons)
{
    math_equation_insert_subtract(buttons->priv->equation);
}


void button_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
button_cb(GtkWidget *widget, MathButtons *buttons)
{
    math_equation_insert(buttons->priv->equation, g_object_get_data(G_OBJECT(widget), "calc_text"));
}


void solve_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
solve_cb(GtkWidget *widget, MathButtons *buttons)
{
    math_equation_solve(buttons->priv->equation);
}


void clear_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
clear_cb(GtkWidget *widget, MathButtons *buttons)
{
    math_equation_clear(buttons->priv->equation);
}


void delete_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
delete_cb(GtkWidget *widget, MathButtons *buttons)
{
    math_equation_delete(buttons->priv->equation);
}


void undo_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
undo_cb(GtkWidget *widget, MathButtons *buttons)
{
    math_equation_undo(buttons->priv->equation);
}


static void
shift_cb(GtkWidget *widget, MathButtons *buttons)
{
    math_equation_shift(buttons->priv->equation, GPOINTER_TO_INT(g_object_get_data(G_OBJECT(widget), "shiftcount")));
}

static void
popup_button_menu(GtkWidget *widget, GtkMenu *menu)
{
    gtk_menu_popup_at_widget (menu,
                              widget,
                              GDK_GRAVITY_SOUTH_WEST,
                              GDK_GRAVITY_NORTH_WEST,
                              NULL);
}


void memory_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
memory_cb(GtkWidget *widget, MathButtons *buttons)
{
    MathVariablePopup *popup;
    GtkAllocation allocation;
    gint x, y;

    popup = math_variable_popup_new(buttons->priv->equation);
    gtk_window_set_transient_for(GTK_WINDOW(popup), GTK_WINDOW(gtk_widget_get_toplevel(widget)));

    gtk_widget_get_allocation(widget, &allocation);
    gdk_window_get_root_coords(gtk_widget_get_window(widget), allocation.x, allocation.y, &x, &y);
    gtk_window_move(GTK_WINDOW(popup), x, y);
    gtk_widget_show(GTK_WIDGET(popup));
}


void shift_left_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
shift_left_cb(GtkWidget *widget, MathButtons *buttons)
{
    if (!buttons->priv->shift_left_menu) {
        gint i;
        GtkWidget *menu;

        menu = buttons->priv->shift_left_menu = gtk_menu_new();
        gtk_menu_set_reserve_toggle_size(GTK_MENU(menu), FALSE);

        for (i = 1; i < 16; i++) {
            GtkWidget *item, *label;
            gchar *format, *text;

            if (i < 10) {
                /* Left Shift Popup: Menu item to shift left by n places (n < 10) */
                format = ngettext("_%d place", "_%d places", i);
            }
            else {
                /* Left Shift Popup: Menu item to shift left by n places (n >= 10) */
                format = ngettext("%d place", "%d places", i);
            }
            text = g_strdup_printf(format, i);
            label = gtk_label_new_with_mnemonic(text);

            item = gtk_menu_item_new();
            g_object_set_data(G_OBJECT(item), "shiftcount", GINT_TO_POINTER(i));
            gtk_container_add(GTK_CONTAINER(item), label);
            gtk_menu_shell_append(GTK_MENU_SHELL(menu), item);
            g_signal_connect(item, "activate", G_CALLBACK(shift_cb), buttons);

            gtk_widget_show(label);
            gtk_widget_show(item);
            g_free(text);
        }
    }

    popup_button_menu(widget, GTK_MENU(buttons->priv->shift_left_menu));
}


void shift_right_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
shift_right_cb(GtkWidget *widget, MathButtons *buttons)
{
    if (!buttons->priv->shift_right_menu) {
        gint i;
        GtkWidget *menu;

        menu = buttons->priv->shift_right_menu = gtk_menu_new();
        gtk_menu_set_reserve_toggle_size(GTK_MENU(menu), FALSE);

        for (i = 1; i < 16; i++) {
            GtkWidget *item, *label;
            gchar *format, *text;

            if (i < 10) {
                /* Right Shift Popup: Menu item to shift right by n places (n < 10) */
                format = ngettext("_%d place", "_%d places", i);
            }
            else {
                /* Right Shift Popup: Menu item to shift right by n places (n >= 10) */
                format = ngettext("%d place", "%d places", i);
            }
            text = g_strdup_printf(format, i);
            label = gtk_label_new_with_mnemonic(text);

            item = gtk_menu_item_new();
            g_object_set_data(G_OBJECT(item), "shiftcount", GINT_TO_POINTER(-i));
            gtk_container_add(GTK_CONTAINER(item), label);
            gtk_menu_shell_append(GTK_MENU_SHELL(menu), item);
            g_signal_connect(item, "activate", G_CALLBACK(shift_cb), buttons);

            gtk_widget_show(label);
            gtk_widget_show(item);
            g_free(text);
        }
    }

    popup_button_menu(widget, GTK_MENU(buttons->priv->shift_right_menu));
}


static void
insert_function_cb(GtkWidget *widget, MathButtons *buttons)
{
    math_equation_insert(buttons->priv->equation, g_object_get_data(G_OBJECT(widget), "function"));
}


void function_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
function_cb(GtkWidget *widget, MathButtons *buttons)
{
    if (!buttons->priv->function_menu) {
        gint i;
        GtkWidget *menu;
        struct
        {
            gchar *name, *function;
        } functions[] =
        {
            { /* Tooltip for the integer component button */
              N_("Integer Component"), "int " },
            { /* Tooltip for the fractional component button */
              N_("Fractional Component"), "frac " },
            { /* Tooltip for the round button */
              N_("Round"), "round " },
            { /* Tooltip for the floor button */
              N_("Floor"), "floor " },
            { /* Tooltip for the ceiling button */
              N_("Ceiling"), "ceil " },
            { /* Tooltip for the ceiling button */
              N_("Sign"), "sgn " },
            { NULL, NULL }
        };

        menu = buttons->priv->function_menu = gtk_menu_new();
        gtk_menu_set_reserve_toggle_size(GTK_MENU(menu), FALSE);

        for (i = 0; functions[i].name != NULL; i++) {
            GtkWidget *item;

            item = gtk_menu_item_new_with_label(_(functions[i].name));
            g_object_set_data(G_OBJECT(item), "function", g_strdup(functions[i].function));
            gtk_menu_shell_append(GTK_MENU_SHELL(menu), item);
            g_signal_connect(item, "activate", G_CALLBACK(insert_function_cb), buttons);
            gtk_widget_show(item);
        }
    }

    popup_button_menu(widget, GTK_MENU(buttons->priv->function_menu));
}

static void
insert_const_cb(GtkWidget *widget, MathButtons *buttons)
{
    math_equation_insert(buttons->priv->equation, g_object_get_data(G_OBJECT(widget), "const"));
}


void const_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
const_cb(GtkWidget *widget, MathButtons *buttons)
{
    if (!buttons->priv->const_menu) {
        gint i;
        GtkWidget *menu;
        struct
        {
            gchar *name, *constant, *tooltip;
        } constants[] =
        {
            { /* Tooltip for the c₀ component button */
              N_("Velocity of Light"), "c₀", N_("299,792,458 m/s") },
            { /* Tooltip for the μ₀ component button */
              N_("Magnetic constant"), "μ₀", N_("1.2566370614×10⁻⁶ N/A²") },
            { /* Tooltip for the ε₀ button */
              N_("Electric constant"), "ε₀", N_("8.85418782×10⁻¹² s⁴A²/m³kg") },
            { /* Tooltip for the G button */
              N_("Newtonian constant of gravitation"), "G",  N_("6.67408×10⁻¹¹ m³/(s²kg)") },
            { /* Tooltip for the h button */
              N_("Planck constant"), "h", N_("6.62607004×10⁻³⁴ m²kg/s") },
            { /* Tooltip for the ｅ button */
              N_("Elementary charge"), "ｅ", N_("1.6021766208(98)×10⁻¹⁹ C") },
            { /* Tooltip for the mₑ button */
              N_("Electron mass"), "mₑ", N_("9.10938356×10⁻³¹ kg") },
            { /* Tooltip for the mₚ button */
              N_("Proton mass"), "mₚ", N_("1.672621898(21)×10⁻²⁷ kg") },
            { /* Tooltip for the Nₐ button */
              N_("Avogrado constant"), "Nₐ", N_("6.02214086×10²³ mol⁻¹") },
            { NULL, NULL, NULL }
        };

        menu = buttons->priv->const_menu = gtk_menu_new();
        gtk_menu_set_reserve_toggle_size(GTK_MENU(menu), FALSE);

        for (i = 0; constants[i].name != NULL; i++) {
            GtkWidget *item;

            item = gtk_menu_item_new_with_label(_(constants[i].name));
            gtk_widget_set_tooltip_text(item, _(constants[i].tooltip));
            g_object_set_data(G_OBJECT(item), "const", g_strdup(constants[i].constant));
            gtk_menu_shell_append(GTK_MENU_SHELL(menu), item);
            g_signal_connect(item, "activate", G_CALLBACK(insert_const_cb), buttons);
            gtk_widget_show(item);
        }
    }

    popup_button_menu(widget, GTK_MENU(buttons->priv->const_menu));
}

void factorize_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
factorize_cb(GtkWidget *widget, MathButtons *buttons)
{
    math_equation_factorize(buttons->priv->equation);
}


void digit_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
digit_cb(GtkWidget *widget, MathButtons *buttons)
{
    math_equation_insert_digit(buttons->priv->equation, GPOINTER_TO_INT(g_object_get_data(G_OBJECT(widget), "calc_digit")));
}


void numeric_point_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
numeric_point_cb(GtkWidget *widget, MathButtons *buttons)
{
    math_equation_insert_numeric_point(buttons->priv->equation);
}



void finc_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
finc_cb(GtkWidget *widget, MathButtons *buttons)
{
    gchar *name;

    name = g_object_get_data(G_OBJECT(widget), "finc_dialog");
    gtk_dialog_run(GTK_DIALOG(GET_WIDGET(buttons->priv->financial_ui, name)));
    gtk_widget_hide(GTK_WIDGET(GET_WIDGET(buttons->priv->financial_ui, name)));
}


void insert_character_code_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
insert_character_code_cb(GtkWidget *widget, MathButtons *buttons)
{
    gtk_window_present(GTK_WINDOW(buttons->priv->character_code_dialog));
}


void finc_activate_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
finc_activate_cb(GtkWidget *widget, MathButtons *buttons)
{
    gint dialog, field;

    dialog = GPOINTER_TO_INT(g_object_get_data(G_OBJECT(widget), "finc_dialog"));
    field = GPOINTER_TO_INT(g_object_get_data(G_OBJECT(widget), "finc_field"));

    if (finc_dialog_fields[dialog][field+1] == NULL) {
        GtkWidget *dialog_widget;
        dialog_widget = gtk_widget_get_toplevel(widget);
        if (gtk_widget_is_toplevel(dialog_widget)) {
            gtk_dialog_response(GTK_DIALOG(dialog_widget),
                                GTK_RESPONSE_OK);
            return;
        }
    }
    else {
        GtkWidget *next_widget;
        next_widget = GET_WIDGET(buttons->priv->financial_ui, finc_dialog_fields[dialog][field+1]);
        gtk_widget_grab_focus(next_widget);
    }
}


void finc_response_cb(GtkWidget *widget, gint response_id, MathButtons *buttons);
G_MODULE_EXPORT
void
finc_response_cb(GtkWidget *widget, gint response_id, MathButtons *buttons)
{
    int dialog;
    int i;
    MPNumber arg[4];
    GtkWidget *entry;

    if (response_id != GTK_RESPONSE_OK)
        return;

    dialog = GPOINTER_TO_INT(g_object_get_data(G_OBJECT(widget), "finc_dialog"));

    for (i = 0; i < 4; i++) {
        if (finc_dialog_fields[dialog][i] == NULL) {
            continue;
        }
        entry = GET_WIDGET(buttons->priv->financial_ui, finc_dialog_fields[dialog][i]);
        mp_set_from_string(gtk_entry_get_text(GTK_ENTRY(entry)), 10, &arg[i]);
        gtk_entry_set_text(GTK_ENTRY(entry), "0");
    }
    gtk_widget_grab_focus(GET_WIDGET(buttons->priv->financial_ui, finc_dialog_fields[dialog][0]));

    do_finc_expression(buttons->priv->equation, dialog, &arg[0], &arg[1], &arg[2], &arg[3]);
}


void character_code_dialog_response_cb(GtkWidget *dialog, gint response_id, MathButtons *buttons);
G_MODULE_EXPORT
void
character_code_dialog_response_cb(GtkWidget *dialog, gint response_id, MathButtons *buttons)
{
    const gchar *text;

    text = gtk_entry_get_text(GTK_ENTRY(buttons->priv->character_code_entry));

    if (response_id == GTK_RESPONSE_OK) {
        MPNumber x;
        int i = 0;

        mp_set_from_integer(0, &x);
        while (TRUE) {
            mp_add_integer(&x, text[i], &x);
            if (text[i+1]) {
                 mp_shift(&x, 8, &x);
                 i++;
            }
            else
                break;
        }

        math_equation_insert_number(buttons->priv->equation, &x);
    }

    gtk_widget_hide(dialog);
}


void character_code_dialog_activate_cb(GtkWidget *entry, MathButtons *buttons);
G_MODULE_EXPORT
void
character_code_dialog_activate_cb(GtkWidget *entry, MathButtons *buttons)
{
    character_code_dialog_response_cb(buttons->priv->character_code_dialog, GTK_RESPONSE_OK, buttons);
}


gboolean character_code_dialog_delete_cb(GtkWidget *dialog, GdkEvent *event, MathButtons *buttons);
G_MODULE_EXPORT
gboolean
character_code_dialog_delete_cb(GtkWidget *dialog, GdkEvent *event, MathButtons *buttons)
{
    character_code_dialog_response_cb(dialog, GTK_RESPONSE_CANCEL, buttons);
    return TRUE;
}


gboolean bit_toggle_cb(GtkWidget *event_box, GdkEventButton *event, MathButtons *buttons);
G_MODULE_EXPORT
gboolean
bit_toggle_cb(GtkWidget *event_box, GdkEventButton *event, MathButtons *buttons)
{
    math_equation_toggle_bit(buttons->priv->equation, GPOINTER_TO_INT(g_object_get_data(G_OBJECT(event_box), "bit_index")));
    return TRUE;
}


static void
remove_trailing_spaces(MathButtons *buttons)
{
    GtkTextMark *insert_mark;
    GtkTextIter start, end;
    insert_mark = gtk_text_buffer_get_insert (GTK_TEXT_BUFFER(buttons->priv->equation));
    gtk_text_buffer_get_iter_at_mark(GTK_TEXT_BUFFER(buttons->priv->equation), &end, insert_mark);
    start = end;
    while (gtk_text_iter_backward_char(&start)) {
        if (!g_unichar_isspace(gtk_text_iter_get_char(&start)))
            break;
        gtk_text_buffer_delete(GTK_TEXT_BUFFER(buttons->priv->equation), &start, &end);
    }
}


void set_superscript_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
set_superscript_cb(GtkWidget *widget, MathButtons *buttons)
{
    if (gtk_toggle_button_get_active(GTK_TOGGLE_BUTTON(widget))) {
        math_equation_set_number_mode(buttons->priv->equation, SUPERSCRIPT);
        if (!gtk_text_buffer_get_has_selection(GTK_TEXT_BUFFER(buttons->priv->equation))) {
            remove_trailing_spaces(buttons);
        }
    }
    else if (math_equation_get_number_mode(buttons->priv->equation) == SUPERSCRIPT)
        math_equation_set_number_mode(buttons->priv->equation, NORMAL);
}


void set_subscript_cb(GtkWidget *widget, MathButtons *buttons);
G_MODULE_EXPORT
void
set_subscript_cb(GtkWidget *widget, MathButtons *buttons)
{
    if (gtk_toggle_button_get_active(GTK_TOGGLE_BUTTON(widget))) {
        math_equation_set_number_mode(buttons->priv->equation, SUBSCRIPT);
        if (!gtk_text_buffer_get_has_selection(GTK_TEXT_BUFFER(buttons->priv->equation))) {
            remove_trailing_spaces(buttons);
        }
    }
    else if (math_equation_get_number_mode(buttons->priv->equation) == SUBSCRIPT)
        math_equation_set_number_mode(buttons->priv->equation, NORMAL);
}


static void
number_mode_changed_cb(MathEquation *equation, GParamSpec *spec, MathButtons *buttons)
{
    GList *i;
    NumberMode mode;

    mode = math_equation_get_number_mode(equation);

    for (i = buttons->priv->superscript_toggles; i; i = i->next) {
        GtkWidget *widget = i->data;
        gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(widget), mode == SUPERSCRIPT);
    }
    for (i = buttons->priv->subscript_toggles; i; i = i->next) {
        GtkWidget *widget = i->data;
        gtk_toggle_button_set_active(GTK_TOGGLE_BUTTON(widget), mode == SUBSCRIPT);
    }
}


static void
math_buttons_set_property(GObject      *object,
                          guint         prop_id,
                          const GValue *value,
                          GParamSpec   *pspec)
{
    MathButtons *self;

    self = MATH_BUTTONS(object);

    switch (prop_id) {
    case PROP_EQUATION:
        self->priv->equation = g_value_get_object(value);
        math_buttons_set_mode(self, self->priv->mode);
        g_signal_connect(self->priv->equation, "notify::display", G_CALLBACK(display_changed_cb), self);
        g_signal_connect(self->priv->equation, "notify::number-mode", G_CALLBACK(number_mode_changed_cb), self);
        g_signal_connect(self->priv->equation, "notify::angle-units", G_CALLBACK(display_changed_cb), self);
        g_signal_connect(self->priv->equation, "notify::number-format", G_CALLBACK(display_changed_cb), self);
        number_mode_changed_cb(self->priv->equation, NULL, self);
        display_changed_cb(self->priv->equation, NULL, self);
        break;
    case PROP_MODE:
        math_buttons_set_mode(self, g_value_get_int(value));
        break;
    case PROP_PROGRAMMING_BASE:
        math_buttons_set_programming_base(self, g_value_get_int(value));
        break;
    default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
        break;
    }
}


static void
math_buttons_get_property(GObject    *object,
                          guint       prop_id,
                          GValue     *value,
                          GParamSpec *pspec)
{
    MathButtons *self;

    self = MATH_BUTTONS(object);

    switch (prop_id) {
    case PROP_EQUATION:
        g_value_set_object(value, self->priv->equation);
        break;
    case PROP_MODE:
        g_value_set_int(value, self->priv->mode);
        break;
    case PROP_PROGRAMMING_BASE:
        g_value_set_int(value, math_buttons_get_programming_base(self));
        break;
    default:
        G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
        break;
    }
}


static void
math_buttons_class_init(MathButtonsClass *klass)
{
    static GEnumValue button_mode_values[] =
    {
      {BASIC,       "basic",       "basic"},
      {ADVANCED,    "advanced",    "advanced"},
      {FINANCIAL,   "financial",   "financial"},
      {PROGRAMMING, "programming", "programming"},
      {0, NULL, NULL}
    };
    GObjectClass *object_class = G_OBJECT_CLASS(klass);

    object_class->get_property = math_buttons_get_property;
    object_class->set_property = math_buttons_set_property;

    button_mode_type = g_enum_register_static("ButtonMode", button_mode_values);

    g_object_class_install_property(object_class,
                                    PROP_EQUATION,
                                    g_param_spec_object("equation",
                                                        "equation",
                                                        "Equation being controlled",
                                                        math_equation_get_type(),
                                                        G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY));
    g_object_class_install_property(object_class,
                                    PROP_MODE,
                                    g_param_spec_enum("mode",
                                                      "mode",
                                                      "Button mode",
                                                      button_mode_type,
                                                      BASIC,
                                                      G_PARAM_READWRITE));
    g_object_class_install_property(object_class,
                                    PROP_PROGRAMMING_BASE,
                                    g_param_spec_int("programming-base",
                                                     "programming-base",
                                                     "Base to use in programming mode",
                                                     2, 16, 10,
                                                     G_PARAM_READWRITE));
}


static void
math_buttons_init(MathButtons *buttons)
{
    buttons->priv = math_buttons_get_instance_private (buttons);
    gtk_box_set_spacing(GTK_BOX(buttons), 6);
    gtk_orientable_set_orientation (GTK_ORIENTABLE (buttons),
                                    GTK_ORIENTATION_VERTICAL);
    buttons->priv->programming_base = 10;
    g_signal_connect(G_OBJECT(buttons), "show", G_CALLBACK(load_buttons), NULL);
}