Add support for entering emoji by name

This commit adds some basic support for entering emoji by name
to GtkIMContextSimple. We respect the input-purpose property and
only support emoji in free-form fields.

To begin an emoji sequence, use Ctrl-Shift-e instead of Ctrl-Shift-u
that is used for hex input. Otherwise, the behavior is the same:
you can can let go of the modifier keys and end the sequence with
space or enter, or hold on to the modifier keys and end the sequence
by releasing them.

Only a limited, fixed set of names is supported:
:-)
8-)
<3
kiss
grin
joy
:-*
xD
like
dislike
up
v
ok
B-)
;-)
;-P
:-p
3(
:-(
;]
:'(
:_(
:((
:o
:|
3-)
>(
>((
O:)
;o
8|
8o
:X
}:)

gtk/gtkimcontextsimple.c

@@ -72,6 +72,7 @@ struct _GtkIMContextSimplePrivate
   gint           tentative_match_len;
 
   guint          in_hex_sequence : 1;
+  guint          in_emoji_sequence : 1;
   guint          modifiers_dropped : 1;
 };
 
@@ -295,9 +296,10 @@ gtk_im_context_simple_commit_char (GtkIMContext *context,
   len = g_unichar_to_utf8 (ch, buf);
   buf[len] = '\0';
 
-  if (priv->tentative_match || priv->in_hex_sequence)
+  if (priv->tentative_match || priv->in_hex_sequence || priv->in_emoji_sequence)
     {
       priv->in_hex_sequence = FALSE;
+      priv->in_emoji_sequence = FALSE;
       priv->tentative_match = 0;
       priv->tentative_match_len = 0;
       g_signal_emit_by_name (context_simple, "preedit-changed");
@@ -865,6 +867,104 @@ check_hex (GtkIMContextSimple *context_simple,
   return TRUE;
 }
 
+typedef struct {
+  const char *name;
+  gunichar ch;
+} EmojiItem;
+
+static EmojiItem emoji[] = {
+  { ":-)",     0x1f642 },
+  { "8-)",     0x1f60d },
+  { "<3",      0x02764 },
+  { "kiss",    0x1f48b },
+  { "grin",    0x1f601 },
+  { "joy",     0x1f602 },
+  { ":-*",     0x1f61a },
+  { "xD",      0x1f606 },
+  { "like",    0x1f44d },
+  { "dislike", 0x1f44e },
+  { "up",      0x1f446 },
+  { "v",       0x0270c },
+  { "ok",      0x1f44c },
+  { "B-)",     0x1f60e },
+  { ":-D",     0x1f603 },
+  { ";-)",     0x1f609 },
+  { ";-P",     0x1f61c },
+  { ":-p",     0x1f60b },
+  { "3(",      0x1f614 },
+  { ":-(",     0x1f61e },
+  { ":]",      0x1f60f },
+  { ":'(",     0x1f622 },
+  { ":_(",     0x1f62d },
+  { ":((",     0x1f629 },
+  { ":o",      0x1f628 },
+  { ":|",      0x1f610 },
+  { "3-)",     0x1f60c },
+  { ">(",      0x1f620 },
+  { ">((",     0x1f621 },
+  { "O:)",     0x1f607 },
+  { ";o",      0x1f630 },
+  { "8|",      0x1f633 },
+  { "8o",      0x1f632 },
+  { ":X",      0x1f637 },
+  { "}:)",     0x1f608 },
+  { NULL, 0 }
+};
+
+static gboolean
+check_emoji (GtkIMContextSimple *context_simple,
+             gint                n_compose)
+{
+  GtkIMContextSimplePrivate *priv = context_simple->priv;
+  GString *str;
+  gint i;
+  gchar buf[7];
+  char *lower;
+
+  priv->tentative_match = 0;
+  priv->tentative_match_len = 0;
+
+  str = g_string_new (NULL);
+
+  i = 0;
+  while (i < n_compose)
+    {
+      gunichar ch;
+
+      ch = gdk_keyval_to_unicode (priv->compose_buffer[i]);
+
+      if (ch == 0)
+        return FALSE;
+
+      if (priv->in_hex_sequence && !g_unichar_isxdigit (ch))
+        return FALSE;
+
+      buf[g_unichar_to_utf8 (ch, buf)] = '\0';
+
+      g_string_append (str, buf);
+
+      ++i;
+    }
+
+  lower = g_utf8_strdown (str->str, str->len);
+
+  for (i = 0; emoji[i].name; i++)
+    {
+      if (strcmp (str->str, emoji[i].name) == 0 ||
+          strcmp (lower, emoji[i].name) == 0)
+        {
+          priv->tentative_match = emoji[i].ch;
+          priv->tentative_match_len = n_compose;
+          break;
+        }
+    }
+
+  g_string_free (str, TRUE);
+  g_free (lower);
+
+  return priv->tentative_match != 0;
+}
+
 static void
 beep_window (GdkWindow *window)
 {
@@ -984,6 +1084,12 @@ canonical_hex_keyval (GdkEventKey *event)
     return 0;
 }
 
+static guint
+canonical_emoji_keyval (GdkEventKey *event)
+{
+  return event->keyval;
+}
+
 static gboolean
 gtk_im_context_simple_filter_keypress (GtkIMContext *context,
 				       GdkEventKey  *event)
@@ -996,32 +1102,36 @@ gtk_im_context_simple_filter_keypress (GtkIMContext *context,
   GdkModifierType hex_mod_mask;
   gboolean have_hex_mods;
   gboolean is_hex_start;
-  gboolean is_hex_end;
+  gboolean is_end;
+  gboolean is_emoji_start;
   gboolean is_backspace;
   gboolean is_escape;
   guint hex_keyval;
+  guint emoji_keyval;
   int i;
   gboolean compose_finish;
   gboolean compose_match;
   gunichar output_char;
+  GtkInputPurpose purpose;
 
   while (priv->compose_buffer[n_compose] != 0)
     n_compose++;
 
   if (event->type == GDK_KEY_RELEASE)
     {
-      if (priv->in_hex_sequence &&
-	  (event->keyval == GDK_KEY_Control_L || event->keyval == GDK_KEY_Control_R ||
+      if ((event->keyval == GDK_KEY_Control_L || event->keyval == GDK_KEY_Control_R ||
 	   event->keyval == GDK_KEY_Shift_L || event->keyval == GDK_KEY_Shift_R))
 	{
-	  if (priv->tentative_match &&
+          if ((priv->in_hex_sequence || priv->in_emoji_sequence) &&
+	      priv->tentative_match &&
 	      g_unichar_validate (priv->tentative_match))
 	    {
 	      gtk_im_context_simple_commit_char (context, priv->tentative_match);
 	      priv->compose_buffer[0] = 0;
 
 	    }
-	  else if (n_compose == 0)
+	  else if (priv->in_emoji_sequence ||
+                   (priv->in_hex_sequence && n_compose == 0))
 	    {
 	      priv->modifiers_dropped = TRUE;
 	    }
@@ -1032,6 +1142,7 @@ gtk_im_context_simple_filter_keypress (GtkIMContext *context,
 
 	      priv->tentative_match = 0;
 	      priv->in_hex_sequence = FALSE;
+	      priv->in_emoji_sequence = FALSE;
 	      priv->compose_buffer[0] = 0;
 
 	      g_signal_emit_by_name (context_simple, "preedit-changed");
@@ -1053,19 +1164,25 @@ gtk_im_context_simple_filter_keypress (GtkIMContext *context,
                                                GDK_MODIFIER_INTENT_PRIMARY_ACCELERATOR);
   hex_mod_mask |= GDK_SHIFT_MASK;
 
-  if (priv->in_hex_sequence && priv->modifiers_dropped)
+  if ((priv->in_hex_sequence || priv->in_emoji_sequence) && priv->modifiers_dropped)
     have_hex_mods = TRUE;
   else
     have_hex_mods = (event->state & (hex_mod_mask)) == hex_mod_mask;
   is_hex_start = event->keyval == GDK_KEY_U;
-  is_hex_end = (event->keyval == GDK_KEY_space ||
-		event->keyval == GDK_KEY_KP_Space ||
-		event->keyval == GDK_KEY_Return ||
-		event->keyval == GDK_KEY_ISO_Enter ||
-		event->keyval == GDK_KEY_KP_Enter);
+  g_object_get (context, "input-purpose", &purpose, NULL);
+  if (purpose == GTK_INPUT_PURPOSE_FREE_FORM)
+    is_emoji_start = event->keyval == GDK_KEY_E;
+  else
+    is_emoji_start = FALSE;
+  is_end = (event->keyval == GDK_KEY_space ||
+            event->keyval == GDK_KEY_KP_Space ||
+            event->keyval == GDK_KEY_Return ||
+	    event->keyval == GDK_KEY_ISO_Enter ||
+	    event->keyval == GDK_KEY_KP_Enter);
   is_backspace = event->keyval == GDK_KEY_BackSpace;
   is_escape = event->keyval == GDK_KEY_Escape;
   hex_keyval = canonical_hex_keyval (event);
+  emoji_keyval = canonical_emoji_keyval (event);
 
   /* If we are already in a non-hex sequence, or
    * this keystroke is not hex modifiers + hex digit, don't filter
@@ -1075,10 +1192,11 @@ gtk_im_context_simple_filter_keypress (GtkIMContext *context,
    * ISO_Level3_Switch.
    */
   if (!have_hex_mods ||
-      (n_compose > 0 && !priv->in_hex_sequence) ||
-      (n_compose == 0 && !priv->in_hex_sequence && !is_hex_start) ||
+      (n_compose > 0 && !priv->in_hex_sequence && !priv->in_emoji_sequence) ||
+      (n_compose == 0 && !priv->in_hex_sequence && !priv->in_emoji_sequence &&
+       !is_hex_start && !is_emoji_start) ||
       (priv->in_hex_sequence && !hex_keyval &&
-       !is_hex_start && !is_hex_end && !is_escape && !is_backspace))
+       !is_hex_start && !is_end && !is_escape && !is_backspace))
     {
       GdkModifierType no_text_input_mask;
 
@@ -1087,7 +1205,7 @@ gtk_im_context_simple_filter_keypress (GtkIMContext *context,
                                       GDK_MODIFIER_INTENT_NO_TEXT_INPUT);
 
       if (event->state & no_text_input_mask ||
-	  (priv->in_hex_sequence && priv->modifiers_dropped &&
+	  ((priv->in_hex_sequence || priv->in_emoji_sequence) && priv->modifiers_dropped &&
 	   (event->keyval == GDK_KEY_Return ||
 	    event->keyval == GDK_KEY_ISO_Enter ||
 	    event->keyval == GDK_KEY_KP_Enter)))
@@ -1097,17 +1215,21 @@ gtk_im_context_simple_filter_keypress (GtkIMContext *context,
     }
   
   /* Handle backspace */
-  if (priv->in_hex_sequence && have_hex_mods && is_backspace)
+  if ((priv->in_hex_sequence || priv->in_emoji_sequence) && have_hex_mods && is_backspace)
     {
       if (n_compose > 0)
 	{
 	  n_compose--;
 	  priv->compose_buffer[n_compose] = 0;
-          check_hex (context_simple, n_compose);
+          if (priv->in_hex_sequence)
+            check_hex (context_simple, n_compose);
+          else if (priv->in_emoji_sequence)
+            check_emoji (context_simple, n_compose);
 	}
       else
 	{
 	  priv->in_hex_sequence = FALSE;
+	  priv->in_emoji_sequence = FALSE;
 	}
 
       g_signal_emit_by_name (context_simple, "preedit-changed");
@@ -1153,6 +1275,20 @@ gtk_im_context_simple_filter_keypress (GtkIMContext *context,
       return TRUE;
     }
   
+  /* Check for emoji sequence start */
+  if (!priv->in_emoji_sequence && have_hex_mods && is_emoji_start)
+    {
+      priv->compose_buffer[0] = 0;
+      priv->in_emoji_sequence = TRUE;
+      priv->modifiers_dropped = FALSE;
+      priv->tentative_match = 0;
+
+      g_signal_emit_by_name (context_simple, "preedit-start");
+      g_signal_emit_by_name (context_simple, "preedit-changed");
+  
+      return TRUE;
+    }
+  
   /* Then, check for compose sequences */
   if (priv->in_hex_sequence)
     {
@@ -1161,29 +1297,42 @@ gtk_im_context_simple_filter_keypress (GtkIMContext *context,
       else if (is_escape)
 	{
 	  gtk_im_context_simple_reset (context);
-	  
 	  return TRUE;
 	}
-      else if (!is_hex_end)
+      else if (!is_end)
 	{
 	  /* non-hex character in hex sequence */
 	  beep_window (event->window);
-	  
 	  return TRUE;
 	}
     }
+  else if (priv->in_emoji_sequence)
+    {
+      if (emoji_keyval)
+        priv->compose_buffer[n_compose++] = emoji_keyval;
+      else if (is_escape)
+        {
+	  gtk_im_context_simple_reset (context);
+	  return TRUE;
+        }
+      else
+        {
+	  beep_window (event->window);
+	  return TRUE;
+        }
+    }
   else
     priv->compose_buffer[n_compose++] = event->keyval;
 
   priv->compose_buffer[n_compose] = 0;
 
-  if (priv->in_hex_sequence)
+  if (priv->in_hex_sequence || priv->in_emoji_sequence)
     {
       /* If the modifiers are still held down, consider the sequence again */
       if (have_hex_mods)
         {
           /* space or return ends the sequence, and we eat the key */
-          if (n_compose > 0 && is_hex_end)
+          if (n_compose > 0 && is_end)
             {
 	      if (priv->tentative_match &&
 		  g_unichar_validate (priv->tentative_match))
@@ -1198,15 +1347,17 @@ gtk_im_context_simple_filter_keypress (GtkIMContext *context,
 
 		  priv->tentative_match = 0;
 		  priv->in_hex_sequence = FALSE;
+		  priv->in_emoji_sequence = FALSE;
 		  priv->compose_buffer[0] = 0;
 		}
             }
-          else if (!check_hex (context_simple, n_compose))
+          else if ((priv->in_hex_sequence && !check_hex (context_simple, n_compose)) ||
+                   (priv->in_emoji_sequence && !check_emoji (context_simple, n_compose)))
 	    beep_window (event->window);
 
 	  g_signal_emit_by_name (context_simple, "preedit-changed");
 
-	  if (!priv->in_hex_sequence)
+	  if (!priv->in_hex_sequence && !priv->in_emoji_sequence)
 	    g_signal_emit_by_name (context_simple, "preedit-end");
 
 	  return TRUE;
@@ -1327,9 +1478,10 @@ gtk_im_context_simple_reset (GtkIMContext *context)
 
   priv->compose_buffer[0] = 0;
 
-  if (priv->tentative_match || priv->in_hex_sequence)
+  if (priv->tentative_match || priv->in_hex_sequence || priv->in_emoji_sequence)
     {
       priv->in_hex_sequence = FALSE;
+      priv->in_emoji_sequence = FALSE;
       priv->tentative_match = 0;
       priv->tentative_match_len = 0;
       g_signal_emit_by_name (context_simple, "preedit-changed");
@@ -1348,11 +1500,11 @@ gtk_im_context_simple_get_preedit_string (GtkIMContext   *context,
   char outbuf[37]; /* up to 6 hex digits */
   int len = 0;
 
-  if (priv->in_hex_sequence)
+  if (priv->in_hex_sequence || priv->in_emoji_sequence)
     {
       int hexchars = 0;
          
-      outbuf[0] = 'u';
+      outbuf[0] = priv->in_hex_sequence ? 'u' : 'e';
       len = 1;
 
       while (priv->compose_buffer[hexchars] != 0)