iOS: Add logging category for input method debugging

Change-Id: If1505b3b5f6ceb18fc8972192d637fc42530f993
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>

src/plugins/platforms/ios/qiosglobal.h

@@ -41,6 +41,16 @@
 
 QT_BEGIN_NAMESPACE
 
+Q_DECLARE_LOGGING_CATEGORY(lcQpaInputMethods);
+
+#if !defined(QT_NO_DEBUG)
+#define qImDebug(...) \
+    for (bool qt_category_enabled = lcQpaInputMethods().isDebugEnabled(); qt_category_enabled; qt_category_enabled = false) \
+        QMessageLogger(QT_MESSAGELOG_FILE, QT_MESSAGELOG_LINE, QT_MESSAGELOG_FUNC, lcQpaInputMethods().categoryName()).debug(__VA_ARGS__)
+#else
+#define qImDebug() QT_NO_QDEBUG_MACRO()
+#endif
+
 class QPlatformScreen;
 
 bool isQtApplication();

src/plugins/platforms/ios/qiosglobal.mm

@@ -46,6 +46,8 @@
 
 QT_BEGIN_NAMESPACE
 
+Q_LOGGING_CATEGORY(lcQpaInputMethods, "qt.qpa.input.methods");
+
 bool isQtApplication()
 {
     // Returns \c true if the plugin is in full control of the whole application. This means