ibus-ui-gtk3: Enable absolute path of engine icon in KDE5

plasma-workspace 5.2 supports the icon full path.
Now the build checks if qtbase-devel is 5.4 or later since
there is no way to check the version of plasma-workspace.

BUG=https://github.com/ibus/ibus/pull/17
TEST=ui/gtk3/ibus-ui-gtk3

Review URL: https://codereview.appspot.com/217310044

3 files changed, 31 insertions, 4 deletions

diff --git a/configure.ac b/configure.ac
index 39c9cad7..8eb6168f 100644
--- a/configure.ac
+++ b/configure.ac
@@ -270,9 +270,25 @@ else
     enable_wayland="no (disabled, use --enable-wayland to enable)"
 fi
 
+enable_appindicator_engine_icon="no"
 if test x"$enable_appindicator" = x"yes"; then
     enable_appindicator="yes (enabled, use --disable-appindicator to disable)"
+
+    # Need qt5-qtbase-devel package
+    # There is no way to check the version of KStatusNotifierItem and
+    # check the version of qtbase here.
+    AC_MSG_CHECKING([for KDE5 appindicator engine icon])
+    PKG_CHECK_EXISTS([Qt5Gui >= 5.4],
+        enable_appindicator_engine_icon="yes"
+    )
+    AC_MSG_RESULT([$enable_appindicator_engine_icon])
+
+fi
+if test x"$enable_appindicator_engine_icon" != x"yes" ; then
+    enable_appindicator_engine_icon="no (disabled, need qtbase-devel 5.4 or later)"
 fi
+AM_CONDITIONAL([ENABLE_APPINDICATOR_ENGINE_ICON],
+               [test x"$enable_appindicator_engine_icon" = x"yes"])
 
 # GObject introspection
 GOBJECT_INTROSPECTION_CHECK([0.6.8])
@@ -639,6 +655,7 @@ Build options:
   Build XIM agent server        $enable_xim
   Build wayland support         $enable_wayland
   Build appindicator support    $enable_appindicator
+  Build appindicator engine icon $enable_appindicator_engine_icon
   Build python library          $enable_python_library
   Build gconf modules           $enable_gconf
   Build memconf modules         $enable_memconf
diff --git a/ui/gtk3/Makefile.am b/ui/gtk3/Makefile.am
index 40cce117..2de227d6 100644
--- a/ui/gtk3/Makefile.am
+++ b/ui/gtk3/Makefile.am
@@ -98,6 +98,10 @@ if ENABLE_APPINDICATOR
 AM_VALAFLAGS += --define=INDICATOR
 endif
 
+if ENABLE_APPINDICATOR_ENGINE_ICON
+AM_VALAFLAGS += --define=INDICATOR_ENGINE_ICON
+endif
+
 libexec_PROGRAMS = ibus-ui-gtk3
 
 ibus_ui_gtk3_SOURCES = \
@@ -136,8 +140,8 @@ CLEANFILES = \
 # References:
 # libappindicator/src/notification-item.xml
 # libappindicator/src/notification-watcher.xml
-# knotifications/src/org.kde.StatusNotifierItem.xml
-# knotifications/src/org.kde.StatusNotifierWatcher.xml
+# kdelibs/kdeui/knotifications/src/org.kde.StatusNotifierItem.xml
+# kdelibs/kdeui/knotifications/src/org.kde.StatusNotifierWatcher.xml
 EXTRA_DIST = \
 	gtkpanel.xml.in \
 	notification-item.xml \
diff --git a/ui/gtk3/panel.vala b/ui/gtk3/panel.vala
index 13798608..c77bd2f7 100644
--- a/ui/gtk3/panel.vala
+++ b/ui/gtk3/panel.vala
@@ -1248,9 +1248,15 @@ class Panel : IBus.PanelService {
                 m_status_icon.set_from_file(icon_name);
             }
             else if (m_icon_type == IconType.INDICATOR) {
-                warning("appindicator requires an icon name in a theme " +
-                        "path instead of the full path: %s", icon_name);
+#if INDICATOR_ENGINE_ICON
+                m_indicator.set_icon_full(icon_name, "");
+#else
+                warning("plasma-workspace 5.2 or later is required to " +
+                        "show the absolute path icon %s. Currently check " +
+                        "qtbase 5.4 since there is no way to check " +
+                        "the version of plasma-workspace.", icon_name);
                 m_indicator.set_icon_full("ibus-engine", "");
+#endif
             }
         } else {
             string language = null;