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, 3 insertions, 4 deletions

diff --git a/src/plugins/platforms/windows/qwindowsintegration.cpp b/src/plugins/platforms/windows/qwindowsintegration.cpp
index f97c23c207..bbb1f68a52 100644
--- a/src/plugins/platforms/windows/qwindowsintegration.cpp
+++ b/src/plugins/platforms/windows/qwindowsintegration.cpp
@@ -264,10 +264,9 @@ QWindowsIntegration::~QWindowsIntegration()
 
 void QWindowsIntegration::initialize()
 {
-    if (QPlatformInputContext *pluginContext = QPlatformInputContextFactory::create())
-        d->m_inputContext.reset(pluginContext);
-    else
-        d->m_inputContext.reset(new QWindowsInputContext);
+    QString icStr = QPlatformInputContextFactory::requested();
+    icStr.isNull() ? d->m_inputContext.reset(new QWindowsInputContext)
+                   : d->m_inputContext.reset(QPlatformInputContextFactory::create(icStr));
 }
 
 bool QWindowsIntegration::hasCapability(QPlatformIntegration::Capability cap) const