[gcalctool] Reformat display for answer format and number bases

[Robert Ancell <rancell src gnome org>]

commit 8024d64ebb10747817270c73862d3cdc0adc5633
Author: Robert Ancell <robert ancell gmail com>
Date:   Thu Apr 22 21:56:22 2010 +1000

    Reformat display for answer format and number bases

 src/math-equation.c |  225 ++++++++++++++++++++++++++++++++++++++++++---------
 1 files changed, 188 insertions(+), 37 deletions(-)
---
diff --git a/src/math-equation.c b/src/math-equation.c
index 82bdb76..f87182e 100644
--- a/src/math-equation.c
+++ b/src/math-equation.c
@@ -138,51 +138,202 @@ get_ans_offsets(MathEquation *equation, gint *start, gint *end)
 
 
 static void
-reformat_display(MathEquation *equation, gint old_base)
+reformat_ans(MathEquation *equation)
 {
-    gchar *text;
+    if (!equation->priv->ans_start)
+        return;
 
-    text = math_equation_get_display(equation);
+    gchar *orig_ans_text;
+    gchar ans_text[MAX_DIGITS];
+    GtkTextIter ans_start, ans_end;
 
-    /* Reformat answer */
-    if (equation->priv->ans_start) {
-        gchar *orig_ans_text;
-        gchar ans_text[MAX_DIGITS];
-        GtkTextIter ans_start, ans_end;
-
-        gtk_text_buffer_get_iter_at_mark(GTK_TEXT_BUFFER(equation), &ans_start, equation->priv->ans_start);
-        gtk_text_buffer_get_iter_at_mark(GTK_TEXT_BUFFER(equation), &ans_end, equation->priv->ans_end);
-        orig_ans_text = gtk_text_buffer_get_text(GTK_TEXT_BUFFER(equation), &ans_start, &ans_end, FALSE);
-        display_make_number(equation, ans_text, MAX_DIGITS, &equation->priv->state.ans);
-        if (strcmp(orig_ans_text, ans_text) != 0) {
-            gint start;
-
-            equation->priv->in_undo_operation = TRUE;
-            equation->priv->in_reformat = TRUE;
-
-            start = gtk_text_iter_get_offset(&ans_start);
-            gtk_text_buffer_delete(GTK_TEXT_BUFFER(equation), &ans_start, &ans_end);
-            gtk_text_buffer_insert_with_tags(GTK_TEXT_BUFFER(equation), &ans_end, ans_text, -1, equation->priv->ans_tag, NULL);
-
-            /* There seems to be a bug in the marks as they alternate being the correct and incorrect ways.  Reset them */
-            gtk_text_buffer_get_iter_at_offset(GTK_TEXT_BUFFER(equation), &ans_start, start);
-            gtk_text_buffer_move_mark(GTK_TEXT_BUFFER(equation), equation->priv->ans_start, &ans_start);
-            gtk_text_buffer_move_mark(GTK_TEXT_BUFFER(equation), equation->priv->ans_end, &ans_end);
-
-            equation->priv->in_reformat = FALSE;
-            equation->priv->in_undo_operation = FALSE;
+    gtk_text_buffer_get_iter_at_mark(GTK_TEXT_BUFFER(equation), &ans_start, equation->priv->ans_start);
+    gtk_text_buffer_get_iter_at_mark(GTK_TEXT_BUFFER(equation), &ans_end, equation->priv->ans_end);
+    orig_ans_text = gtk_text_buffer_get_text(GTK_TEXT_BUFFER(equation), &ans_start, &ans_end, FALSE);
+    display_make_number(equation, ans_text, MAX_DIGITS, &equation->priv->state.ans);
+    if (strcmp(orig_ans_text, ans_text) != 0) {
+        gint start;
+
+        equation->priv->in_undo_operation = TRUE;
+        equation->priv->in_reformat = TRUE;
+
+        start = gtk_text_iter_get_offset(&ans_start);
+        gtk_text_buffer_delete(GTK_TEXT_BUFFER(equation), &ans_start, &ans_end);
+        gtk_text_buffer_insert_with_tags(GTK_TEXT_BUFFER(equation), &ans_end, ans_text, -1, equation->priv->ans_tag, NULL);
+
+        /* There seems to be a bug in the marks as they alternate being the correct and incorrect ways.  Reset them */
+        gtk_text_buffer_get_iter_at_offset(GTK_TEXT_BUFFER(equation), &ans_start, start);
+        gtk_text_buffer_move_mark(GTK_TEXT_BUFFER(equation), equation->priv->ans_start, &ans_start);
+        gtk_text_buffer_move_mark(GTK_TEXT_BUFFER(equation), equation->priv->ans_end, &ans_end);
+
+        equation->priv->in_reformat = FALSE;
+        equation->priv->in_undo_operation = FALSE;
+    }
+    gtk_text_buffer_get_iter_at_mark(GTK_TEXT_BUFFER(equation), &ans_start, equation->priv->ans_start);
+    gtk_text_buffer_get_iter_at_mark(GTK_TEXT_BUFFER(equation), &ans_end, equation->priv->ans_end);
+    g_free(orig_ans_text);
+}
+
+
+/* NOTE: Not efficent but easy to write */
+// FIXME: This is just a lexer - use the same lexer as the solver
+static void
+reformat_base(MathEquation *equation, gint old_base)
+{
+    gunichar sub_zero, sub_nine;
+    gchar *text, *read_iter;
+    gboolean in_number = FALSE, have_radix = FALSE;
+    gint offset = 0, offset_step = 0, max_digit = 0, base = -1, base_offset;
+    gint ans_start, ans_end;
+
+    if (equation->priv->base == old_base)
+        return;
+
+    sub_zero = g_utf8_get_char("â??");
+    sub_nine = g_utf8_get_char("â??");
+
+    read_iter = text = math_equation_get_display(equation);
+    get_ans_offsets(equation, &ans_start, &ans_end);
+    while (TRUE) {
+        gunichar c;
+        gint digit = -1, sub_digit = -1;
+
+        /* See what digit this character is */
+        c = g_utf8_get_char(read_iter);
+        if (c >= sub_zero && c <= sub_nine)
+            sub_digit = c - sub_zero;
+        else if (c >= 'a' && c <= 'z')
+            digit = c - 'a';
+        else if (c >= 'A' && c <= 'Z')
+            digit = c - 'A';
+        else
+            digit = g_unichar_digit_value(c);
+
+        /* Don't mess with ans */
+        if (offset >= ans_start && offset <= ans_end) {
+            digit = -1;
+            sub_digit = -1;
+        }
+
+        if (in_number && digit >= 0) {
+            if (digit > max_digit)
+                max_digit = digit;
+        }
+        else if (in_number && sub_digit >= 0) {
+            if (base < 0) {
+                base_offset = offset;
+                base = 0;
+            }
+
+            base = base * 10 + sub_digit;
+        }
+        else if (in_number) {
+            /* Allow one radix inside a number */
+            if (!have_radix && base < 0 && strncmp(read_iter, equation->priv->radix, strlen(equation->priv->radix)) == 0) {
+                have_radix = TRUE;
+                read_iter += strlen(equation->priv->radix);
+                offset += g_utf8_strlen(equation->priv->radix, -1);
+                continue;
+            }
+
+            /* If had no base then insert it */
+            if (base < 0) {
+                GtkTextIter iter;
+                gint multiplier = 1;
+                gint b = old_base;
+                const char *digits[] = {"â??", "â??", "â??", "â??", "â??", "â??", "â??", "â??", "â??", "â??"};
+
+                equation->priv->in_undo_operation = TRUE;
+                equation->priv->in_reformat = TRUE;
+
+                while (b / multiplier != 0)
+                    multiplier *= 10;
+                while (multiplier != 1) {
+                    int d;
+                    multiplier /= 10;
+                    d = b / multiplier;
+                    gtk_text_buffer_get_iter_at_offset(GTK_TEXT_BUFFER(equation), &iter, offset + offset_step);
+                    gtk_text_buffer_insert(GTK_TEXT_BUFFER(equation), &iter, digits[d], -1);
+                    offset_step++;
+                    b -= d * multiplier;
+                }
+
+                equation->priv->in_reformat = FALSE;
+                equation->priv->in_undo_operation = FALSE;
+            }
+            /* Remove the base if the current value */
+            else if (max_digit < base && base == equation->priv->base) {
+                GtkTextIter start, end;
+
+                equation->priv->in_undo_operation = TRUE;
+                equation->priv->in_reformat = TRUE;
+
+                gtk_text_buffer_get_iter_at_offset(GTK_TEXT_BUFFER(equation), &start, base_offset + offset_step);
+                gtk_text_buffer_get_iter_at_offset(GTK_TEXT_BUFFER(equation), &end, offset + offset_step);
+                gtk_text_buffer_delete(GTK_TEXT_BUFFER(equation), &start, &end);
+                offset_step -= offset - base_offset;
+
+                equation->priv->in_reformat = FALSE;
+                equation->priv->in_undo_operation = FALSE;
+            }
+
+            in_number = FALSE;
+        }
+        else if (digit >= 0) {
+            in_number = TRUE;
+            have_radix = FALSE;
+            base = -1;
+            max_digit = digit;
         }
-        gtk_text_buffer_get_iter_at_mark(GTK_TEXT_BUFFER(equation), &ans_start, equation->priv->ans_start);
-        gtk_text_buffer_get_iter_at_mark(GTK_TEXT_BUFFER(equation), &ans_end, equation->priv->ans_end);
-        g_free(orig_ans_text);
+
+        if (c == '\0')
+            break;
+               
+        read_iter = g_utf8_next_char(read_iter);
+        offset++;
     }
 
-    // FIXME: Need to know old base to do base changes
-    // FIXME: Need to keep cursor location correct
+    g_free(text);
+}
+
+
+static void
+reformat_separators(MathEquation *equation)
+{
+#if 0
+    gchar *text, *read_iter;
+    gboolean in_number = FALSE, in_fraction = FALSE;
+
+    text = math_equation_get_display(equation);
+
+    /* Find numbers in display, and modify if necessary */
+    read_iter = text;
+    while(*read_iter != '\0') {
+        gunichar c;
+      
+        c = g_utf8_get_char(read_iter);
+
+        if (strncmp(read_iter, equation->priv->tsep, strlen(equation->priv->tsep)) == 0)
+            ;
+        read_iter = g_utf8_next_char(read_iter);
+    }
 
-    /* Find numbers in display, format and then replace if changed */
-  
     g_free(text);
+#endif
+}
+
+
+static void
+reformat_display(MathEquation *equation, gint old_base)
+{
+    /* Change ans */
+    reformat_ans(equation);
+
+    /* Add/remove base suffixes if have changed base */
+    reformat_base(equation, old_base);
+
+    /* Add/remove thousands separators */
+    reformat_separators(equation);
 }