text: Allow selectability without editability

Being able to select text and being able to edit text are two separate
capabilities, but ClutterText only allows the former with the latter.

The ClutterText:selectable property is set to TRUE by default, given
that it depends on the :editable property; this implies that all
ClutterText instances now are going to show a cursor as soon as they get
key focused. Obviously, this would make labels look a bit off — but if
you have a label then you would not give it key focus, either by
explicitly calling clutter_actor_grab_focus(), or by setting it as
reactive and allowing it to be clicked.

If this turns out to be a problem, we have various ways to avoid showing
a cursor — for instance, we could change the default value of the
selectable property, and ensure that setting the :editable property to
TRUE would also set the :selectable property as a side effect. Or we
could hide the cursor until the first button/touch press event. Finally,
we could always back this commit out if it proves to be too much of a
breakage for existing code bases.

https://bugzilla.gnome.org/show_bug.cgi?id=757470

clutter/clutter-text.c

@@ -309,6 +309,16 @@ clutter_text_queue_redraw (ClutterActor *self)
   clutter_actor_queue_redraw (self);
 }
 
+static gboolean
+clutter_text_should_draw_cursor (ClutterText *self)
+{
+  ClutterTextPrivate *priv = self->priv;
+
+  return priv->editable ||
+         priv->selectable ||
+         priv->cursor_visible;
+}
+
 #define clutter_actor_queue_redraw \
   Please_use_clutter_text_queue_redraw_instead
 
@@ -1602,18 +1612,15 @@ selection_paint (ClutterText *self)
   ClutterTextPrivate *priv = self->priv;
   ClutterActor *actor = CLUTTER_ACTOR (self);
   guint8 paint_opacity = clutter_actor_get_paint_opacity (actor);
+  const ClutterColor *color;
 
   if (!priv->has_focus)
     return;
 
-  if (priv->editable && priv->cursor_visible)
+  if (!clutter_text_should_draw_cursor (self))
-    {
+    return;
-      const ClutterColor *color;
-      gint position;
 
-      position = priv->position;
+  if (priv->position == priv->selection_bound)
-
-      if (position == priv->selection_bound)
     {
       /* No selection, just draw the cursor */
       if (priv->cursor_color_set)
@@ -1682,7 +1689,6 @@ selection_paint (ClutterText *self)
       cogl_framebuffer_pop_clip (fb);
     }
 }
-}
 
 static gint
 clutter_text_move_word_backward (ClutterText *self,
@@ -1852,7 +1858,7 @@ clutter_text_press (ClutterActor *actor,
   /* if a ClutterText is just used for display purposes, then we
    * should ignore the events we receive
    */
-  if (!priv->editable)
+  if (!(priv->editable || priv->selectable))
     return CLUTTER_EVENT_PROPAGATE;
 
   clutter_actor_grab_key_focus (actor);
@@ -2265,7 +2271,8 @@ clutter_text_paint (ClutterActor *self)
    * editable, in which case we want to paint at least the
    * cursor
    */
-  if (n_chars == 0 && (!priv->editable || !priv->cursor_visible))
+  if (n_chars == 0 &&
+      !clutter_text_should_draw_cursor (text))
     return;
 
   if (priv->editable && priv->single_line_mode)
@@ -2299,7 +2306,7 @@ clutter_text_paint (ClutterActor *self)
         }
     }
 
-  if (priv->editable && priv->cursor_visible)
+  if ((priv->editable || priv->selectable) && priv->cursor_visible)
     clutter_text_ensure_cursor_position (text);
 
   if (priv->editable && priv->single_line_mode)
@@ -2492,7 +2499,9 @@ clutter_text_get_paint_volume (ClutterActor       *self,
 
       /* If the cursor is visible then that will likely be drawn
          outside of the ink rectangle so we should merge that in */
-      if (priv->editable && priv->cursor_visible && priv->has_focus)
+      if ((priv->editable || priv->selectable) &&
+          priv->cursor_visible &&
+          priv->has_focus)
         {
           ClutterPaintVolume cursor_paint_volume;
 
@@ -2653,11 +2662,7 @@ clutter_text_allocate (ClutterActor           *self,
 static gboolean
 clutter_text_has_overlaps (ClutterActor *self)
 {
-  ClutterTextPrivate *priv = CLUTTER_TEXT (self)->priv;
+  return clutter_text_should_draw_cursor ((ClutterText *) self);
-
-  return priv->editable ||
-         priv->selectable ||
-         priv->cursor_visible;
 }
 
 static void