[gnome-builder] spellcheck: allow dynamic enabling via begin/end calls

[Christian Hergert <chergert src gnome org>]

commit ab695fd5857c811f7670afd65ce50b8411338337
Author: Christian Hergert <chergert redhat com>
Date:   Sun Jul 16 13:46:13 2017 -0700

    spellcheck: allow dynamic enabling via begin/end calls
    
    This allows views to dynamically enable spellcheck features on
    a buffer by calling the begin/end pairs. This allows both full
    time enablement of spellcheck features as well as only enabling
    during spellcheck operations.

 plugins/spellcheck/gbp-spell-buffer-addin.c |  106 ++++++++++++++++++++++++---
 plugins/spellcheck/gbp-spell-buffer-addin.h |    4 +-
 2 files changed, 99 insertions(+), 11 deletions(-)
---
diff --git a/plugins/spellcheck/gbp-spell-buffer-addin.c b/plugins/spellcheck/gbp-spell-buffer-addin.c
index cb9f3f0..516d392 100644
--- a/plugins/spellcheck/gbp-spell-buffer-addin.c
+++ b/plugins/spellcheck/gbp-spell-buffer-addin.c
@@ -30,6 +30,14 @@ struct _GbpSpellBufferAddin
   /* Owned spellchecker instance */
   GspellChecker *spellchecker;
 
+  /* To allow for dynamic enabling of the inline spellcheck, we keep
+   * track of how many views need it. We will enable the feature in
+   * the buffer if it has manually been enabled (see @enabled) or if
+   * this value is >= 1.
+   */
+  gint count;
+
+  /* Manual enabling of inline checking */
   guint enabled : 1;
 };
 
@@ -39,6 +47,14 @@ enum {
   N_PROPS
 };
 
+static gboolean
+gbp_spell_buffer_addin_get_enabled (GbpSpellBufferAddin *self)
+{
+  g_assert (GBP_IS_SPELL_BUFFER_ADDIN (self));
+
+  return self->enabled || self->count > 0;
+}
+
 static void
 gbp_spell_buffer_addin_apply (GbpSpellBufferAddin *self)
 {
@@ -48,21 +64,28 @@ gbp_spell_buffer_addin_apply (GbpSpellBufferAddin *self)
 
   g_assert (GBP_IS_SPELL_BUFFER_ADDIN (self));
 
-  if (self->enabled == FALSE || self->buffer == NULL)
+  /* We might be disposed */
+  if (self->buffer == NULL)
+    return;
+
+  spell_buffer = gspell_text_buffer_get_from_gtk_text_buffer (GTK_TEXT_BUFFER (self->buffer));
+
+  if (!gbp_spell_buffer_addin_get_enabled (self))
     {
+      gspell_text_buffer_set_spell_checker (spell_buffer, NULL);
       g_clear_object (&self->spellchecker);
       return;
     }
 
-  /* The returned GspellTextBuffer is owned by self->buffer */
-  spell_buffer = gspell_text_buffer_get_from_gtk_text_buffer (GTK_TEXT_BUFFER (self->buffer));
-  g_assert (GSPELL_IS_TEXT_BUFFER (spell_buffer));
+  if (self->spellchecker == NULL)
+    {
 
-  /* Setup the spell checker for the buffer. We retrain the spellchecker
-   * instance so that we can add words/modify the dictionary at runtime.
-   */
-  self->spellchecker = gspell_checker_new (NULL);
-  gspell_text_buffer_set_spell_checker (spell_buffer, self->spellchecker);
+      /* Setup the spell checker for the buffer. We retrain the spellchecker
+       * instance so that we can add words/modify the dictionary at runtime.
+       */
+      self->spellchecker = gspell_checker_new (NULL);
+      gspell_text_buffer_set_spell_checker (spell_buffer, self->spellchecker);
+    }
 
   IDE_EXIT;
 }
@@ -126,7 +149,7 @@ gbp_spell_buffer_addin_get_property (GObject    *object,
   switch (prop_id)
     {
     case PROP_ENABLED:
-      g_value_set_boolean (value, self->enabled);
+      g_value_set_boolean (value, gbp_spell_buffer_addin_get_enabled (self));
       break;
 
     default:
@@ -195,3 +218,66 @@ gbp_spell_buffer_addin_get_checker (GbpSpellBufferAddin *self)
 
   return self->spellchecker;
 }
+
+/**
+ * gbp_spell_buffer_addin_begin_checking:
+ * @self: a #GbpSpellBufferAddin
+ *
+ * Views should call this function when they begin their spellchecking
+ * process. It dynamically enables various features on the buffer that
+ * are necessary for spellchecking.
+ *
+ * When done, the consumer MUST call gbp_spell_buffer_addin_end_checking()
+ * to complete the process. If no more views are active, spellchecking
+ * may be disabled on the buffer.
+ *
+ * Since: 3.26
+ */
+void
+gbp_spell_buffer_addin_begin_checking (GbpSpellBufferAddin *self)
+{
+  gboolean before_state;
+  gboolean after_state;
+
+  g_return_if_fail (GBP_IS_SPELL_BUFFER_ADDIN (self));
+  g_return_if_fail (self->count >= 0);
+
+  before_state = gbp_spell_buffer_addin_get_enabled (self);
+  self->count++;
+  after_state = gbp_spell_buffer_addin_get_enabled (self);
+
+  if (before_state != after_state)
+    {
+      gbp_spell_buffer_addin_apply (self);
+      g_object_notify_by_pspec (G_OBJECT (self), properties [PROP_ENABLED]);
+    }
+}
+
+/**
+ * gbp_spell_buffer_addin_end_checking:
+ * @self: a #GbpSpellBufferAddin
+ *
+ * Completes a spellcheck operation. The buffer will return to it's original
+ * state. Thay may mean inline checking is disabled.
+ *
+ * Returns:
+ */
+void
+gbp_spell_buffer_addin_end_checking (GbpSpellBufferAddin *self)
+{
+  gboolean before_state;
+  gboolean after_state;
+
+  g_return_if_fail (GBP_IS_SPELL_BUFFER_ADDIN (self));
+  g_return_if_fail (self->count >= 0);
+
+  before_state = gbp_spell_buffer_addin_get_enabled (self);
+  self->count--;
+  after_state = gbp_spell_buffer_addin_get_enabled (self);
+
+  if (before_state != after_state)
+    {
+      gbp_spell_buffer_addin_apply (self);
+      g_object_notify_by_pspec (G_OBJECT (self), properties [PROP_ENABLED]);
+    }
+}
diff --git a/plugins/spellcheck/gbp-spell-buffer-addin.h b/plugins/spellcheck/gbp-spell-buffer-addin.h
index 7251a6e..b5ed444 100644
--- a/plugins/spellcheck/gbp-spell-buffer-addin.h
+++ b/plugins/spellcheck/gbp-spell-buffer-addin.h
@@ -27,6 +27,8 @@ G_BEGIN_DECLS
 
 G_DECLARE_FINAL_TYPE (GbpSpellBufferAddin, gbp_spell_buffer_addin, GBP, SPELL_BUFFER_ADDIN, GObject)
 
-GspellChecker *gbp_spell_buffer_addin_get_checker (GbpSpellBufferAddin *self);
+GspellChecker *gbp_spell_buffer_addin_get_checker    (GbpSpellBufferAddin *self);
+void           gbp_spell_buffer_addin_begin_checking (GbpSpellBufferAddin *self);
+void           gbp_spell_buffer_addin_end_checking   (GbpSpellBufferAddin *self);
 
 G_END_DECLS