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, 4 insertions, 3 deletions

diff --git a/src/plugins/platforms/cocoa/qcocoaintegration.mm b/src/plugins/platforms/cocoa/qcocoaintegration.mm
index 2e6bfc95db..051a1c8710 100644
--- a/src/plugins/platforms/cocoa/qcocoaintegration.mm
+++ b/src/plugins/platforms/cocoa/qcocoaintegration.mm
@@ -47,6 +47,7 @@
 #include "qcocoamimetypes.h"
 #include "qcocoaaccessibility.h"
 
+#include <qpa/qplatforminputcontextfactory_p.h>
 #include <qpa/qplatformaccessibility.h>
 #include <qpa/qplatforminputcontextfactory_p.h>
 #include <QtCore/qcoreapplication.h>
@@ -286,9 +287,9 @@ QCocoaIntegration::QCocoaIntegration(const QStringList &paramList)
         qWarning("Creating multiple Cocoa platform integrations is not supported");
     mInstance = this;
 
-    mInputContext.reset(QPlatformInputContextFactory::create());
-    if (mInputContext.isNull())
-        mInputContext.reset(new QCocoaInputContext());
+    QString icStr = QPlatformInputContextFactory::requested();
+    icStr.isNull() ? mInputContext.reset(new QCocoaInputContext)
+                   : mInputContext.reset(QPlatformInputContextFactory::create(icStr));
 
     initResources();
     QMacAutoReleasePool pool;