Add capabilities to QPlatformInputContext.

Add a capability enumeration to QPlatformInputContext and
use that to turn off input methods for hidden text depending
on platform support. Disable on Windows.

Task-number: QTBUG-40691
Change-Id: I9909005de1f21316ec8f64e2729f1fffcd37c7c3
Reviewed-by: Lars Knoll <lars.knoll@digia.com>
Reviewed-by: Björn Breitmeyer <bjoern.breitmeyer@kdab.com>
Reviewed-by: Liang Qi <liang.qi@theqtcompany.com>

1 files changed, 9 insertions, 3 deletions

diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index fe92ead846..8983a6fbb2 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -3400,15 +3400,21 @@ void QGuiApplicationPrivate::_q_updateFocusObject(QObject *object)
 {
     Q_Q(QGuiApplication);
 
+    QPlatformInputContext *inputContext = platformIntegration()->inputContext();
     bool enabled = false;
-    if (object) {
-        QInputMethodQueryEvent query(Qt::ImEnabled);
+    if (object && inputContext) {
+        QInputMethodQueryEvent query(Qt::ImEnabled | Qt::ImHints);
         QGuiApplication::sendEvent(object, &query);
         enabled = query.value(Qt::ImEnabled).toBool();
+        if (enabled) {
+            static const bool supportsHiddenText = inputContext->hasCapability(QPlatformInputContext::HiddenTextCapability);
+            const Qt::InputMethodHints hints = static_cast<Qt::InputMethodHints>(query.value(Qt::ImHints).toInt());
+            if ((hints & Qt::ImhHiddenText) && !supportsHiddenText)
+                enabled = false;
+        }
     }
 
     QPlatformInputContextPrivate::setInputMethodAccepted(enabled);
-    QPlatformInputContext *inputContext = platformIntegration()->inputContext();
     if (inputContext)
         inputContext->setFocusObject(object);
     emit q->focusObjectChanged(object);