QLineEdit: Disable input methods for password unless IME supports hidden text

Move the checking logic from QGuiApplicationPrivate::_q_updateFocusObject()
to QInputMethodPrivate::objectAcceptsInputMethod(), which is also called
from QWidget::updateMicroFocus() via QInputMethod::update().

Fixes: QTBUG-56767
Change-Id: Ia4cce5e7e766008df891537048d5daf739c010ff
Reviewed-by: Alex Blasche <alexander.blasche@qt.io>

3 files changed, 19 insertions, 15 deletions

diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
index 9bf2a33e2a..34f453341f 100644
--- a/src/gui/kernel/qguiapplication.cpp
+++ b/src/gui/kernel/qguiapplication.cpp
@@ -84,6 +84,7 @@
 #include "private/qcursor_p.h"
 #include "private/qopenglcontext_p.h"
 #include "private/qinputdevicemanager_p.h"
+#include "private/qinputmethod_p.h"
 #include "private/qtouchdevice_p.h"
 
 #include <qpa/qplatformthemefactory_p.h>
@@ -4030,18 +4031,7 @@ void QGuiApplicationPrivate::_q_updateFocusObject(QObject *object)
     Q_Q(QGuiApplication);
 
     QPlatformInputContext *inputContext = platformIntegration()->inputContext();
-    bool enabled = false;
-    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;
-        }
-    }
+    const bool enabled = inputContext && QInputMethodPrivate::objectAcceptsInputMethod(object);
 
     QPlatformInputContextPrivate::setInputMethodAccepted(enabled);
     if (inputContext)
diff --git a/src/gui/kernel/qinputmethod.cpp b/src/gui/kernel/qinputmethod.cpp
index 365b088840..a319529442 100644
--- a/src/gui/kernel/qinputmethod.cpp
+++ b/src/gui/kernel/qinputmethod.cpp
@@ -390,15 +390,29 @@ void QInputMethod::invokeAction(Action a, int cursorPosition)
         ic->invokeAction(a, cursorPosition);
 }
 
+static inline bool platformSupportsHiddenText()
+{
+    const QPlatformInputContext *inputContext = QGuiApplicationPrivate::platformIntegration()->inputContext();
+    return inputContext && inputContext->hasCapability(QPlatformInputContext::HiddenTextCapability);
+}
+
 bool QInputMethodPrivate::objectAcceptsInputMethod(QObject *object)
 {
     bool enabled = false;
     if (object) {
-        QInputMethodQueryEvent query(Qt::ImEnabled);
+        // If the platform does not support hidden text, query the hints
+        // in addition and disable in case of ImhHiddenText.
+        static const bool supportsHiddenText = platformSupportsHiddenText();
+        QInputMethodQueryEvent query(supportsHiddenText
+                                     ? Qt::InputMethodQueries(Qt::ImEnabled)
+                                     : Qt::InputMethodQueries(Qt::ImEnabled | Qt::ImHints));
         QGuiApplication::sendEvent(object, &query);
         enabled = query.value(Qt::ImEnabled).toBool();
+        if (enabled && !supportsHiddenText
+            && Qt::InputMethodHints(query.value(Qt::ImHints).toInt()).testFlag(Qt::ImhHiddenText)) {
+            enabled = false;
+        }
     }
-
     return enabled;
 }
 
diff --git a/src/gui/kernel/qinputmethod_p.h b/src/gui/kernel/qinputmethod_p.h
index 81723bbe30..0c2b739d92 100644
--- a/src/gui/kernel/qinputmethod_p.h
+++ b/src/gui/kernel/qinputmethod_p.h
@@ -80,7 +80,7 @@ public:
 
     void _q_connectFocusObject();
     void _q_checkFocusObject(QObject *object);
-    bool objectAcceptsInputMethod(QObject *object);
+    static bool objectAcceptsInputMethod(QObject *object);
 
     QTransform inputItemTransform;
     QRectF inputRectangle;