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>

src/gui/kernel/qplatforminputcontext_qpa.cpp

@@ -52,6 +52,11 @@ QPlatformInputContext::~QPlatformInputContext()
 {
 }
 
+bool QPlatformInputContext::isValid() const
+{
+    return false;
+}
+
 void QPlatformInputContext::reset()
 {
 }

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);

src/platformsupport/inputcontext/qplatforminputcontextfactory_qpa.cpp

@@ -46,14 +46,13 @@
 
 #include "qguiapplication.h"
 #include "qdebug.h"
+#include <stdlib.h>
 
 QT_BEGIN_NAMESPACE
 
 #if !defined(QT_NO_LIBRARY) && !defined(QT_NO_SETTINGS)
 Q_GLOBAL_STATIC_WITH_ARGS(QFactoryLoader, loader,
     (QPlatformInputContextFactoryInterface_iid, QLatin1String("/platforminputcontexts"), Qt::CaseInsensitive))
-Q_GLOBAL_STATIC_WITH_ARGS(QFactoryLoader, directLoader,
-                          (QPlatformInputContextFactoryInterface_iid, QLatin1String(""), Qt::CaseInsensitive))
 #endif
 
 QStringList QPlatformInputContextFactory::keys()
@@ -79,5 +78,33 @@ QPlatformInputContext *QPlatformInputContextFactory::create(const QString& key)
     return ret;
 }
 
+QPlatformInputContext *QPlatformInputContextFactory::create()
+{
+    QPlatformInputContext *ic = 0;
+
+    QString icString = QString::fromLatin1(getenv("QT_IM_MODULE"));
+    ic = create(icString);
+    qDebug() << ic << ic->isValid();
+    if (ic && ic->isValid())
+        return ic;
+
+    delete ic;
+    ic = 0;
+
+    QStringList k = keys();
+    for (int i = 0; i < k.size(); ++i) {
+        if (k.at(i) == icString)
+            continue;
+        ic = create(k.at(i));
+        if (ic && ic->isValid())
+            return ic;
+        delete ic;
+        ic = 0;
+    }
+
+    return 0;
+}
+
+
 QT_END_NAMESPACE
 

src/platformsupport/inputcontext/qplatforminputcontextfactory_qpa_p.h

@@ -68,6 +68,7 @@ class QPlatformInputContextFactory
 public:
     static QStringList keys();
     static QPlatformInputContext *create(const QString &key);
+    static QPlatformInputContext *create();
 };
 
 QT_END_NAMESPACE

src/plugins/platforminputcontexts/ibus/qibusplatforminputcontext.h

@@ -53,7 +53,7 @@ public:
     QIBusPlatformInputContext();
     ~QIBusPlatformInputContext();
 
-    Q_INVOKABLE bool isValid() const;
+    bool isValid() const;
 
     void invokeAction(QInputPanel::Action a, int x);
     void reset(void);

src/plugins/platforms/xcb/qxcbintegration.cpp

@@ -62,10 +62,8 @@
 #include <EGL/egl.h>
 #endif
 
-#if defined(XCB_USE_IBUS)
 #include <private/qplatforminputcontextfactory_qpa_p.h>
 #include <qplatforminputcontext_qpa.h>
-#endif
 
 #if defined(XCB_USE_GLX)
 #include "qglxintegration.h"
@@ -101,18 +99,7 @@ QXcbIntegration::QXcbIntegration(const QStringList &parameters)
     m_fontDatabase = new QGenericUnixFontDatabase();
     m_nativeInterface = new QXcbNativeInterface;
 
-    m_inputContext = 0;
-#if defined(XCB_USE_IBUS)
-    QPlatformInputContext *platformInputContext = QPlatformInputContextFactory::create("ibus");
-    if (platformInputContext) {
-        bool retval;
-        QMetaObject::invokeMethod(platformInputContext, "isValid", Qt::DirectConnection, Q_RETURN_ARG(bool, retval));
-        if (retval)
-            m_inputContext = platformInputContext;
-    }
-    if (platformInputContext && !m_inputContext)
-        delete platformInputContext;
-#endif
+    m_inputContext = QPlatformInputContextFactory::create();
 }
 
 QXcbIntegration::~QXcbIntegration()

src/plugins/platforms/xcb/qxcbkeyboard.cpp

@@ -49,9 +49,7 @@
 #include <private/qguiapplication_p.h>
 #include <stdio.h>
 
-#if defined(XCB_USE_IBUS)
 #include <qplatforminputcontext_qpa.h>
-#endif
 
 #ifndef XK_ISO_Left_Tab
 #define XK_ISO_Left_Tab         0xFE20
@@ -1030,7 +1028,6 @@ void QXcbKeyboard::handleKeyEvent(QWindow *window, QEvent::Type type, xcb_keycod
     xcb_keysym_t sym = lookupString(window, state, code, type, &chars);
 
 
-#if defined(XCB_USE_IBUS)
     if (QObject* inputContext = QGuiApplicationPrivate::platformIntegration()->inputContext()) {
         bool retval;
         QMetaObject::invokeMethod(inputContext, "x11FilterEvent", Qt::DirectConnection,
@@ -1042,7 +1039,6 @@ void QXcbKeyboard::handleKeyEvent(QWindow *window, QEvent::Type type, xcb_keycod
         if (retval)
             return;
     }
-#endif
 
     Qt::KeyboardModifiers modifiers;
     int qtcode = 0;