[evolution] [ESpellEntry] Do not touch entry when its IM is in the preedit mode

[Milan Crha <mcrha src gnome org>]

commit 3deb64b7cadf2f329ecef9c6bae92d0ea9f5e8d8
Author: Milan Crha <mcrha redhat com>
Date:   Tue Aug 11 12:15:53 2015 +0200

    [ESpellEntry] Do not touch entry when its IM is in the preedit mode
    
    When a user enters text with a preedit involved, the ESpellEntry
    should not touch the attributes of the entry, because it breaks
    the preedit buffer reset logic. It's not visible with the first word,
    but entering the second without a delimiter shows garbage. The attribute
    change also garbled the preedit highlighting in the entry.

 e-util/e-spell-entry.c |   26 ++++++++++++++++++++++----
 1 files changed, 22 insertions(+), 4 deletions(-)
---
diff --git a/e-util/e-spell-entry.c b/e-util/e-spell-entry.c
index 559b372..adebbd8 100644
--- a/e-util/e-spell-entry.c
+++ b/e-util/e-spell-entry.c
@@ -44,6 +44,8 @@ struct _ESpellEntryPrivate {
 
        ESpellChecker *spell_checker;
        guint active_languages_handler_id;
+
+       gboolean im_in_preedit;
 };
 
 enum {
@@ -711,6 +713,16 @@ spell_entry_active_languages_cb (ESpellChecker *spell_checker,
 }
 
 static void
+spell_entry_preedit_changed_cb (ESpellEntry *spell_entry,
+                               const gchar *preedit_text,
+                               gpointer user_data)
+{
+       g_return_if_fail (E_IS_SPELL_ENTRY (spell_entry));
+
+       spell_entry->priv->im_in_preedit = preedit_text && *preedit_text;
+}
+
+static void
 spell_entry_set_property (GObject *object,
                           guint property_id,
                           const GValue *value,
@@ -809,6 +821,8 @@ spell_entry_constructed (GObject *object)
        /* Chain up to parent's constructed() method. */
        G_OBJECT_CLASS (e_spell_entry_parent_class)->constructed (object);
 
+       g_signal_connect (spell_entry, "preedit-changed", G_CALLBACK (spell_entry_preedit_changed_cb), NULL);
+
        /* Install a default spell checker if there is not one already. */
        spell_checker = e_spell_entry_get_spell_checker (spell_entry);
        if (spell_checker == NULL) {
@@ -825,11 +839,14 @@ spell_entry_draw (GtkWidget *widget,
                   cairo_t *cr)
 {
        ESpellEntry *spell_entry = E_SPELL_ENTRY (widget);
-       GtkEntry *entry = GTK_ENTRY (widget);
-       PangoLayout *layout;
 
-       layout = gtk_entry_get_layout (entry);
-       pango_layout_set_attributes (layout, spell_entry->priv->attr_list);
+       if (!spell_entry->priv->im_in_preedit) {
+               GtkEntry *entry = GTK_ENTRY (widget);
+               PangoLayout *layout;
+
+               layout = gtk_entry_get_layout (entry);
+               pango_layout_set_attributes (layout, spell_entry->priv->attr_list);
+       }
 
        /* Chain up to parent's draw() method. */
        return GTK_WIDGET_CLASS (e_spell_entry_parent_class)->
@@ -898,6 +915,7 @@ e_spell_entry_init (ESpellEntry *spell_entry)
        spell_entry->priv = E_SPELL_ENTRY_GET_PRIVATE (spell_entry);
        spell_entry->priv->attr_list = pango_attr_list_new ();
        spell_entry->priv->checking_enabled = TRUE;
+       spell_entry->priv->im_in_preedit = FALSE;
 
        g_signal_connect (
                spell_entry, "popup-menu",