Implement navigation through history stack equations using keyboard

5 files changed, 66 insertions, 2 deletions

diff --git a/src/math-history-entry.c b/src/math-history-entry.c
index 8a6b4ae..8277f88 100644
--- a/src/math-history-entry.c
+++ b/src/math-history-entry.c
@@ -88,6 +88,12 @@ math_history_entry_insert_entry(MathHistoryEntry *history_entry, const gchar *eq
     #undef get_widget
 }
 
+gchar *
+math_history_entry_get_equation(MathHistoryEntry *history_entry)
+{
+    return gtk_widget_get_tooltip_text(history_entry->priv->equation_label);
+}
+
 static void
 math_history_entry_class_init(MathHistoryEntryClass *klass)
 {
diff --git a/src/math-history-entry.h b/src/math-history-entry.h
index 53ccc88..2133ade 100644
--- a/src/math-history-entry.h
+++ b/src/math-history-entry.h
@@ -44,6 +44,9 @@ math_history_entry_new(MathEquation *equation);
 void
 math_history_entry_insert_entry(MathHistoryEntry *history_entry, const gchar *equation, const gchar *answer_four_digits, const gchar *answer_nine_digits);
 
+gchar *
+math_history_entry_get_equation(MathHistoryEntry *history_entry);
+
 G_END_DECLS
 
 #endif /* MATH_HISTORY_ENTRY_VIEW_H */
diff --git a/src/math-history.c b/src/math-history.c
index 49d63a2..403a04f 100644
--- a/src/math-history.c
+++ b/src/math-history.c
@@ -22,6 +22,7 @@ struct MathHistoryPrivate
 
     gchar *last_answer;
     gchar *last_equation;
+    int current; /* 0 is the first entry, rows-1 the most recent entry */
     int rows;
     GtkWidget *listbox;
 };
@@ -82,6 +83,7 @@ math_history_insert_entry (MathHistory *history, char *equation, MPNumber *answe
     history->priv->last_answer = g_strdup(answer_nine_digits);
     history->priv->last_equation = g_strdup(equation);
     history->priv->rows++;
+    history->priv->current = history->priv->rows;
     g_signal_emit_by_name(history, "row-added");
 
     g_free(answer_four_digits);
@@ -94,12 +96,33 @@ math_history_clear(MathHistory *history)
     GList *children, *iter;
 
     history->priv->rows = 0;
+    history->priv->current = 0;
     children = gtk_container_get_children(GTK_CONTAINER(history->priv->listbox));
     for (iter = children; iter != NULL; iter = g_list_next(iter))
           gtk_widget_destroy(GTK_WIDGET(iter->data));
     g_list_free(children);
 }
 
+gpointer
+math_history_get_entry_at(MathHistory *history, int index)
+{
+    if (index >= 0 && index < history->priv->rows)
+        return MATH_HISTORY_ENTRY(gtk_list_box_get_row_at_index(GTK_LIST_BOX(history->priv->listbox), index));
+    return NULL;
+}
+
+void
+math_history_set_current(MathHistory *history, int value)
+{
+    history->priv->current = CLAMP (history->priv->current + value, 0, history->priv->rows - 1);
+}
+
+int
+math_history_get_current(MathHistory *history)
+{
+    return history->priv->current;
+}
+
 static void
 math_history_class_init(MathHistoryClass *klass)
 {
@@ -124,6 +147,7 @@ math_history_init(MathHistory *history)
     gtk_scrolled_window_set_policy(GTK_SCROLLED_WINDOW(history), GTK_POLICY_NEVER, GTK_POLICY_AUTOMATIC);
     gtk_scrolled_window_set_placement(GTK_SCROLLED_WINDOW(history), GTK_CORNER_TOP_LEFT);
 
+    history->priv->current = 0;
     history->priv->rows = 0;
     history->priv->last_answer = g_strdup("");
     history->priv->last_equation = g_strdup("");
diff --git a/src/math-history.h b/src/math-history.h
index 7c7b079..87dab7a 100644
--- a/src/math-history.h
+++ b/src/math-history.h
@@ -45,6 +45,15 @@ math_history_new(MathEquation *equation);
 void
 math_history_insert_entry(MathHistory *history, char *equation, MPNumber *answer, int number_base);
 
+gpointer
+math_history_get_entry_at(MathHistory *history, int index);
+
+void
+math_history_set_current(MathHistory *history, int value);
+
+int
+math_history_get_current(MathHistory *history);
+
 void
 math_history_clear(MathHistory *history);
 
diff --git a/src/math-window.c b/src/math-window.c
index 08ac3e3..e872f4f 100644
--- a/src/math-window.c
+++ b/src/math-window.c
@@ -202,7 +202,29 @@ key_press_cb(MathWindow *window, GdkEventKey *event)
     gboolean result;
     g_signal_emit_by_name(window->priv->display, "key-press-event", event, &result);
 
-    if (math_buttons_get_mode (window->priv->buttons) == PROGRAMMING && (event->state & GDK_CONTROL_MASK) == GDK_CONTROL_MASK) {
+    /* Keyboard navigation for history */
+    if ((event->state & GDK_MOD1_MASK) == GDK_MOD1_MASK && (event->keyval == GDK_KEY_Up || event->keyval == GDK_KEY_Down))
+    {
+        switch (event->keyval)
+        {
+            case GDK_KEY_Up:
+                math_history_set_current(window->priv->history, -1);
+                break;
+            case GDK_KEY_Down:
+                math_history_set_current(window->priv->history, 1);
+                break;
+        }
+
+        MathHistoryEntry *entry = math_history_get_entry_at(window->priv->history, math_history_get_current(window->priv->history));
+        if (entry)
+        {
+            gchar *equation_string = math_history_entry_get_equation(entry);
+            math_equation_set(window->priv->equation, equation_string);
+            g_free(equation_string);
+        }
+        return TRUE;
+    }
+    else if (math_buttons_get_mode (window->priv->buttons) == PROGRAMMING && (event->state & GDK_CONTROL_MASK) == GDK_CONTROL_MASK) {
         switch(event->keyval)
         {
         /* Binary */
@@ -540,7 +562,7 @@ static void create_menu(MathWindow* window)
 
     menu = add_menu(window->priv->menu_bar, VIEW_MENU_LABEL);
     window->priv->view_history_menu_item = add_menu_item(menu, gtk_check_menu_item_new_with_mnemonic(VIEW_HISTORY_LABEL), G_CALLBACK(history_check_toggled_cb), window);
-    gtk_widget_add_accelerator(window->priv->view_history_menu_item, "activate", accel_group, GDK_KEY_H, GDK_CONTROL_MASK, GTK_ACCEL_VISIBLE);
+    gtk_widget_add_accelerator(window->priv->view_history_menu_item, "activate", accel_group, GDK_KEY_H, GDK_CONTROL_MASK | GDK_SHIFT_MASK, GTK_ACCEL_VISIBLE);
 
     menu = add_menu(window->priv->menu_bar, HELP_MENU_LABEL);
     menu_item = add_menu_item(menu, gtk_image_menu_item_new_from_icon("help-browser", HELP_CONTENTS_LABEL, accel_group), G_CALLBACK(help_cb), window);