Make inputcontext plugin loading a bit more generic

Add a create() method to the inputcontext factory that
takes no arguments.
Add a virtual isValid() to QPlatformInputContext to
determine whether it actually works.
Remove IBUS dependencies in the xcb code so that it
can also load other plugins.

Change-Id: I6345a845f48fd4b3cacf6d8652711b16835a235c
Reviewed-on: http://codereview.qt-project.org/4487
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Lars Knoll <lars.knoll@nokia.com>

2 files changed, 7 insertions, 0 deletions

diff --git a/src/gui/kernel/qplatforminputcontext_qpa.cpp b/src/gui/kernel/qplatforminputcontext_qpa.cpp
index 328d4f5b74..6482d4a34a 100644
--- a/src/gui/kernel/qplatforminputcontext_qpa.cpp
+++ b/src/gui/kernel/qplatforminputcontext_qpa.cpp
@@ -52,6 +52,11 @@ QPlatformInputContext::~QPlatformInputContext()
 {
 }
 
+bool QPlatformInputContext::isValid() const
+{
+    return false;
+}
+
 void QPlatformInputContext::reset()
 {
 }
diff --git a/src/gui/kernel/qplatforminputcontext_qpa.h b/src/gui/kernel/qplatforminputcontext_qpa.h
index 804200708a..35763edf13 100644
--- a/src/gui/kernel/qplatforminputcontext_qpa.h
+++ b/src/gui/kernel/qplatforminputcontext_qpa.h
@@ -60,6 +60,8 @@ public:
     QPlatformInputContext();
     virtual ~QPlatformInputContext();
 
+    virtual bool isValid() const;
+
     virtual void reset();
     virtual void commit();
     virtual void update(Qt::InputMethodQueries);