Harmonize input context selection

Input context selection works differently across platforms. On some
platforms it is not possible to request a specific context at all
(e.g. Wayland). This will be unified, depending on the environment
variable "QT_IM_MODULE", you will get:
- null:  default (platform) context, if defined (otherwise no context)
- empty: no context
- set:   set one, if it exists and is valid (otherwise no context)

[ChangeLog][Platform Specific Changes] Haromnized input context selection.
QT_IM_MODULE environment variable will be taken into account.

Change-Id: Ic8f826fbc6ace25941cd19b9b086943e848fbe01
Reviewed-by: Lars Knoll <lars.knoll@theqtcompany.com>
Reviewed-by: Nedim Hadzic <nedim.hadzic@pelagicore.com>

1 files changed, 14 insertions, 30 deletions

diff --git a/src/gui/kernel/qplatforminputcontextfactory.cpp b/src/gui/kernel/qplatforminputcontextfactory.cpp
index a7660e76ae..9d55b778ce 100644
--- a/src/gui/kernel/qplatforminputcontextfactory.cpp
+++ b/src/gui/kernel/qplatforminputcontextfactory.cpp
@@ -56,48 +56,32 @@ QStringList QPlatformInputContextFactory::keys()
 #endif
 }
 
-QPlatformInputContext *QPlatformInputContextFactory::create(const QString& key)
+QString QPlatformInputContextFactory::requested()
 {
-    QStringList paramList = key.split(QLatin1Char(':'));
-    const QString platform = paramList.takeFirst().toLower();
-
-#if !defined(QT_NO_LIBRARY) && !defined(QT_NO_SETTINGS)
-    if (QPlatformInputContext *ret = qLoadPlugin1<QPlatformInputContext, QPlatformInputContextPlugin>(loader(), platform, paramList))
-        return ret;
-#endif
-    return 0;
+    QByteArray env = qgetenv("QT_IM_MODULE");
+    return env.isNull() ? QString() : QString::fromLocal8Bit(env);
 }
 
-QPlatformInputContext *QPlatformInputContextFactory::create()
+QPlatformInputContext *QPlatformInputContextFactory::create(const QString& key)
 {
-    QPlatformInputContext *ic = 0;
-
-    QString icString = QString::fromLatin1(qgetenv("QT_IM_MODULE"));
-
-    if (icString == QLatin1String("none"))
-        return 0;
+#if !defined(QT_NO_LIBRARY) && !defined(QT_NO_SETTINGS)
+    QStringList paramList = key.split(QLatin1Char(':'));
+    const QString platform = paramList.takeFirst().toLower();
 
-    ic = create(icString);
+    QPlatformInputContext *ic = qLoadPlugin1<QPlatformInputContext, QPlatformInputContextPlugin>
+                                             (loader(), platform, paramList);
     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;
-    }
-
+#endif
     return 0;
 }
 
+QPlatformInputContext *QPlatformInputContextFactory::create()
+{
+    return create(requested());
+}
 
 QT_END_NAMESPACE