Improved the support for input methods in Graphics View.

This patch improves the graphics view support for input
methods in several ways:

  * A new ItemAcceptsInputMethod flag is introduced to serve
    the same purpose for graphics items as WA_InputMethodEnabled
    does for widgets: Input method support can be controlled
    individually for each item.
  * The input method sensitivity of a view (i.e. the value of
    the WA_InputMethodEnabled flag) is updated dynamically
    whenever the input method support of the current focus
    item may change.
  * Input contexts are reset whenever an item that supports
    input methods loses focus.

Reviewed-by: janarve
Task-number: 254492

9 files changed, 90 insertions, 10 deletions

diff --git a/src/gui/graphicsview/qgraphicsitem.cpp b/src/gui/graphicsview/qgraphicsitem.cpp
index c82c2e5..a5ee7e6 100644
--- a/src/gui/graphicsview/qgraphicsitem.cpp
+++ b/src/gui/graphicsview/qgraphicsitem.cpp
@@ -323,6 +323,10 @@
     performance reasons, these notifications are disabled by default. You must
     enable this flag to receive notifications for position and transform
     changes. This flag was introduced in Qt 4.6.
+
+    \value ItemAcceptsInputMethod The item supports input methods typically
+    used for Asian languages.
+    This flag was introduced in Qt 4.6.
 */
 
 /*!
@@ -1486,6 +1490,12 @@ void QGraphicsItem::setFlags(GraphicsItemFlags flags)
             d_ptr->scene->d_func()->needSortTopLevelItems = 1;
     }
 
+    if ((flags & ItemAcceptsInputMethod) != (oldFlags & ItemAcceptsInputMethod)) {
+        // Update input method sensitivity in any views.
+        if (d_ptr->scene)
+            d_ptr->scene->d_func()->updateInputMethodSensitivityInViews();
+    }
+
     if (d_ptr->scene) {
         d_ptr->scene->d_func()->markDirty(this, QRectF(),
                                           /*invalidateChildren=*/true,
@@ -9840,6 +9850,9 @@ QDebug operator<<(QDebug debug, QGraphicsItem::GraphicsItemFlag flag)
     case QGraphicsItem::ItemSendsGeometryChanges:
         str = "ItemSendsGeometryChanges";
         break;
+    case QGraphicsItem::ItemAcceptsInputMethod:
+        str = "ItemAcceptsInputMethod";
+        break;
     }
     debug << str;
     return debug;
diff --git a/src/gui/graphicsview/qgraphicsitem.h b/src/gui/graphicsview/qgraphicsitem.h
index b0571c2..d26110a 100644
--- a/src/gui/graphicsview/qgraphicsitem.h
+++ b/src/gui/graphicsview/qgraphicsitem.h
@@ -98,7 +98,8 @@ public:
         ItemStacksBehindParent = 0x100,
         ItemUsesExtendedStyleOption = 0x200,
         ItemHasNoContents = 0x400,
-        ItemSendsGeometryChanges = 0x800
+        ItemSendsGeometryChanges = 0x800,
+        ItemAcceptsInputMethod = 0x1000
         // NB! Don't forget to increase the d_ptr->flags bit field by 1 when adding a new flag.
     };
     Q_DECLARE_FLAGS(GraphicsItemFlags, GraphicsItemFlag)
diff --git a/src/gui/graphicsview/qgraphicsitem_p.h b/src/gui/graphicsview/qgraphicsitem_p.h
index a977e1e..46ec6fe 100644
--- a/src/gui/graphicsview/qgraphicsitem_p.h
+++ b/src/gui/graphicsview/qgraphicsitem_p.h
@@ -415,7 +415,7 @@ public:
     quint32 fullUpdatePending : 1;
 
     // New 32 bits
-    quint32 flags : 12;
+    quint32 flags : 13;
     quint32 dirtyChildrenBoundingRect : 1;
     quint32 paintedViewBoundingRectsNeedRepaint : 1;
     quint32 dirtySceneTransform  : 1;
@@ -426,7 +426,7 @@ public:
     quint32 ignoreOpacity : 1;
     quint32 acceptTouchEvents : 1;
     quint32 acceptedTouchBeginEvent : 1;
-    quint32 unused : 10; // feel free to use
+    quint32 unused : 9; // feel free to use
 
     // Optional stacking order
     int globalStackingOrder;
diff --git a/src/gui/graphicsview/qgraphicsproxywidget.cpp b/src/gui/graphicsview/qgraphicsproxywidget.cpp
index 0b421ad..5fac6cf 100644
--- a/src/gui/graphicsview/qgraphicsproxywidget.cpp
+++ b/src/gui/graphicsview/qgraphicsproxywidget.cpp
@@ -451,6 +451,22 @@ void QGraphicsProxyWidgetPrivate::updateProxyGeometryFromWidget()
 
 /*!
     \internal
+*/
+void QGraphicsProxyWidgetPrivate::updateProxyInputMethodAcceptanceFromWidget()
+{
+    Q_Q(QGraphicsProxyWidget);
+    if (!widget)
+        return;
+
+    QWidget *focusWidget = widget->focusWidget();
+    if (!focusWidget)
+        focusWidget = widget;
+    q->setFlag(QGraphicsItem::ItemAcceptsInputMethod,
+               focusWidget->testAttribute(Qt::WA_InputMethodEnabled));
+}
+
+/*!
+    \internal
 
     Embeds \a subWin as a subwindow of this proxy widget. \a subWin must be a top-level
     widget and a descendant of the widget managed by this proxy. A separate subproxy
@@ -690,6 +706,8 @@ void QGraphicsProxyWidgetPrivate::setWidget_helper(QWidget *newWidget, bool auto
 
     updateProxyGeometryFromWidget();
 
+    updateProxyInputMethodAcceptanceFromWidget();
+
     // Hook up the event filter to keep the state up to date.
     newWidget->installEventFilter(q);
     QObject::connect(newWidget, SIGNAL(destroyed()), q, SLOT(_q_removeWidgetSlot()));
@@ -1303,8 +1321,8 @@ void QGraphicsProxyWidget::focusInEvent(QFocusEvent *event)
 	if (d->widget && d->widget->focusWidget()) {
 	    d->widget->focusWidget()->setFocus(event->reason());
 	    return;
-	}
-	break;
+        }
+        break;
     }
 }
 
diff --git a/src/gui/graphicsview/qgraphicsproxywidget_p.h b/src/gui/graphicsview/qgraphicsproxywidget_p.h
index ec5400a..fbc9f6c 100644
--- a/src/gui/graphicsview/qgraphicsproxywidget_p.h
+++ b/src/gui/graphicsview/qgraphicsproxywidget_p.h
@@ -102,6 +102,8 @@ public:
     void updateWidgetGeometryFromProxy();
     void updateProxyGeometryFromWidget();
 
+    void updateProxyInputMethodAcceptanceFromWidget();
+
     QPointF mapToReceiver(const QPointF &pos, const QWidget *receiver) const;
 
     enum ChangeMode {
diff --git a/src/gui/graphicsview/qgraphicsscene.cpp b/src/gui/graphicsview/qgraphicsscene.cpp
index c3f72e6..0c3abd4 100644
--- a/src/gui/graphicsview/qgraphicsscene.cpp
+++ b/src/gui/graphicsview/qgraphicsscene.cpp
@@ -242,6 +242,7 @@
 #include <QtGui/qtooltip.h>
 #include <QtGui/qtransform.h>
 #include <QtGui/qgesture.h>
+#include <QtGui/qinputcontext.h>
 #include <private/qapplication_p.h>
 #include <private/qobject_p.h>
 #ifdef Q_WS_X11
@@ -3175,6 +3176,8 @@ void QGraphicsScene::addItem(QGraphicsItem *item)
 
     // Deliver post-change notification
     item->itemChange(QGraphicsItem::ItemSceneHasChanged, newSceneVariant);
+
+    d->updateInputMethodSensitivityInViews();
 }
 
 /*!
@@ -3450,6 +3453,8 @@ void QGraphicsScene::removeItem(QGraphicsItem *item)
 
     // Deliver post-change notification
     item->itemChange(QGraphicsItem::ItemSceneHasChanged, newSceneVariant);
+
+    d->updateInputMethodSensitivityInViews();
 }
 
 /*!
@@ -3504,6 +3509,17 @@ void QGraphicsScene::setFocusItem(QGraphicsItem *item, Qt::FocusReason focusReas
         d->lastFocusItem = d->focusItem;
         d->focusItem = 0;
         d->sendEvent(d->lastFocusItem, &event);
+
+        if (d->lastFocusItem
+            && (d->lastFocusItem->flags() & QGraphicsItem::ItemAcceptsInputMethod)) {
+            // Reset any visible preedit text
+            QInputMethodEvent imEvent;
+            d->sendEvent(d->lastFocusItem, &imEvent);
+
+            // Close any external input method panel
+            for (int i = 0; i < d->views.size(); ++i)
+                d->views.at(i)->inputContext()->reset();
+        }
     }
 
     if (item) {
@@ -3516,6 +3532,8 @@ void QGraphicsScene::setFocusItem(QGraphicsItem *item, Qt::FocusReason focusReas
         QFocusEvent event(QEvent::FocusIn, focusReason);
         d->sendEvent(item, &event);
     }
+
+    d->updateInputMethodSensitivityInViews();
 }
 
 /*!
@@ -3699,7 +3717,7 @@ void QGraphicsScene::setForegroundBrush(const QBrush &brush)
 QVariant QGraphicsScene::inputMethodQuery(Qt::InputMethodQuery query) const
 {
     Q_D(const QGraphicsScene);
-    if (!d->focusItem)
+    if (!d->focusItem || !(d->focusItem->flags() & QGraphicsItem::ItemAcceptsInputMethod))
         return QVariant();
     const QTransform matrix = d->focusItem->sceneTransform();
     QVariant value = d->focusItem->inputMethodQuery(query);
@@ -4662,16 +4680,16 @@ void QGraphicsScene::wheelEvent(QGraphicsSceneWheelEvent *wheelEvent)
     subclass to receive input method events for the scene.
 
     The default implementation forwards the event to the focusItem().
-    If no item currently has focus, this function does nothing.
+    If no item currently has focus or the current focus item does not
+    accept input methods, this function does nothing.
 
     \sa QGraphicsItem::inputMethodEvent()
 */
 void QGraphicsScene::inputMethodEvent(QInputMethodEvent *event)
 {
     Q_D(QGraphicsScene);
-    if (!d->focusItem)
-        return;
-    d->sendEvent(d->focusItem, event);
+    if (d->focusItem && (d->focusItem->flags() & QGraphicsItem::ItemAcceptsInputMethod))
+        d->sendEvent(d->focusItem, event);
 }
 
 /*!
@@ -6128,6 +6146,11 @@ void QGraphicsScenePrivate::enableTouchEventsOnViews()
         view->viewport()->setAttribute(Qt::WA_AcceptTouchEvents, true);
 }
 
+void QGraphicsScenePrivate::updateInputMethodSensitivityInViews()
+{
+    for (int i = 0; i < views.size(); ++i)
+        views.at(i)->d_func()->updateInputMethodSensitivity();
+}
 
 QT_END_NAMESPACE
 
diff --git a/src/gui/graphicsview/qgraphicsscene_p.h b/src/gui/graphicsview/qgraphicsscene_p.h
index d2d603a..dc720a7 100644
--- a/src/gui/graphicsview/qgraphicsscene_p.h
+++ b/src/gui/graphicsview/qgraphicsscene_p.h
@@ -316,6 +316,8 @@ public:
     bool sendTouchBeginEvent(QGraphicsItem *item, QTouchEvent *touchEvent);
     bool allItemsIgnoreTouchEvents;
     void enableTouchEventsOnViews();
+
+    void updateInputMethodSensitivityInViews();
 };
 
 QT_END_NAMESPACE
diff --git a/src/gui/graphicsview/qgraphicsview.cpp b/src/gui/graphicsview/qgraphicsview.cpp
index 56a69f7..3b29552 100644
--- a/src/gui/graphicsview/qgraphicsview.cpp
+++ b/src/gui/graphicsview/qgraphicsview.cpp
@@ -280,6 +280,7 @@ static const int QGRAPHICSVIEW_PREALLOC_STYLE_OPTIONS = 503; // largest prime <
 #include <QtGui/qpainter.h>
 #include <QtGui/qscrollbar.h>
 #include <QtGui/qstyleoption.h>
+#include <QtGui/qinputcontext.h>
 #ifdef Q_WS_X11
 #include <private/qt_x11_p.h>
 #endif
@@ -1017,6 +1018,22 @@ QList<QGraphicsItem *> QGraphicsViewPrivate::findItems(const QRegion &exposedReg
 }
 
 /*!
+    \internal
+
+    Enables input methods for the view if and only if the current focus item of
+    the scene accepts input methods. Call function whenever that condition has
+    potentially changed.
+*/
+void QGraphicsViewPrivate::updateInputMethodSensitivity()
+{
+    Q_Q(QGraphicsView);
+    q->setAttribute(
+        Qt::WA_InputMethodEnabled,
+        scene && scene->focusItem()
+        && scene->focusItem()->flags() & QGraphicsItem::ItemAcceptsInputMethod);
+}
+
+/*!
     Constructs a QGraphicsView. \a parent is passed to QWidget's constructor.
 */
 QGraphicsView::QGraphicsView(QWidget *parent)
@@ -1538,6 +1555,8 @@ void QGraphicsView::setScene(QGraphicsScene *scene)
     } else {
         d->recalculateContentSize();
     }
+
+    d->updateInputMethodSensitivity();
 }
 
 /*!
@@ -2929,6 +2948,7 @@ void QGraphicsView::dragMoveEvent(QDragMoveEvent *event)
 void QGraphicsView::focusInEvent(QFocusEvent *event)
 {
     Q_D(QGraphicsView);
+    d->updateInputMethodSensitivity();
     QAbstractScrollArea::focusInEvent(event);
     if (d->scene)
         QApplication::sendEvent(d->scene, event);
diff --git a/src/gui/graphicsview/qgraphicsview_p.h b/src/gui/graphicsview/qgraphicsview_p.h
index 8c62f73..09d842d 100644
--- a/src/gui/graphicsview/qgraphicsview_p.h
+++ b/src/gui/graphicsview/qgraphicsview_p.h
@@ -181,6 +181,7 @@ public:
     QPointF mapToScene(const QPointF &point) const;
     QRectF mapToScene(const QRectF &rect) const;
     static void translateTouchEvent(QGraphicsViewPrivate *d, QTouchEvent *touchEvent);
+    void updateInputMethodSensitivity();
 };
 
 QT_END_NAMESPACE