Merge branch 'fix-infobar-gtk3'

Make wxInfoBar appear for GTK+ 3 version between 3.10 and 3.29.

Closes https://github.com/wxWidgets/wxWidgets/pull/855

docs/changes.txt

@@ -106,6 +106,7 @@ All (GUI):
 wxGTK:
 
 - Implement wxTextCtrl::HitTest() for single line controls.
+- Fix not showing wxInfoBar with GTK+ 3 < 3.22.29.
 - Fix the build with glib < 2.32 (e.g. CentOS 6).
 
 wxMSW:

samples/dialogs/dialogs.cpp

@@ -686,6 +686,7 @@ MyFrame::MyFrame(const wxString& title)
 
     // ... changing the colours and/or fonts
     m_infoBarAdvanced->SetOwnBackgroundColour(0xc8ffff);
+    m_infoBarAdvanced->SetForegroundColour(0x123312);
     m_infoBarAdvanced->SetFont(GetFont().Bold().Larger());
 
     // ... and changing the effect (only does anything under MSW currently)

src/gtk/infobar.cpp

@@ -145,6 +145,31 @@ bool wxInfoBar::Create(wxWindow *parent, wxWindowID winid)
     GTKConnectWidget("response", G_CALLBACK(wxgtk_infobar_response));
     GTKConnectWidget("close", G_CALLBACK(wxgtk_infobar_close));
 
+    // Work around GTK+ bug https://bugzilla.gnome.org/show_bug.cgi?id=710888
+    // by disabling the transition when showing it: without this, it's not
+    // shown at all.
+    //
+    // Compile-time check is needed because GtkRevealer is new in 3.10.
+#if GTK_CHECK_VERSION(3, 10, 0)
+    // Run-time check is needed because the bug was introduced in 3.10 and
+    // fixed in 3.22.29 (see 6b4d95e86dabfcdaa805fbf068a99e19736a39a4 and a
+    // couple of previous commits in GTK+ repository).
+    if ( gtk_check_version(3, 10, 0) == NULL &&
+            gtk_check_version(3, 22, 29) != NULL )
+    {
+        GObject* const
+            revealer = gtk_widget_get_template_child(GTK_WIDGET(m_widget),
+                                                     GTK_TYPE_INFO_BAR,
+                                                     "revealer");
+        if ( revealer )
+        {
+            gtk_revealer_set_transition_type(GTK_REVEALER (revealer),
+                                             GTK_REVEALER_TRANSITION_TYPE_NONE);
+            gtk_revealer_set_transition_duration(GTK_REVEALER (revealer), 0);
+        }
+    }
+#endif // GTK+ >= 3.10
+
     return true;
 }