Changes: Disable panning while text magnifier is in use.

RevBy: Pekka Vuorela
Details: MTextMagnifier, or rather its overlay parent, grabs the
pan gesture and by consuming it the gesture never reaches pannable
widgets.

8 files changed, 286 insertions, 8 deletions

diff --git a/src/views/mtextmagnifier.cpp b/src/views/mtextmagnifier.cpp
index a49a82d4..5997ab86 100644
--- a/src/views/mtextmagnifier.cpp
+++ b/src/views/mtextmagnifier.cpp
@@ -26,11 +26,11 @@
 #include <QPainter>
 #include <QStyleOptionGraphicsItem>
 
+
 MTextMagnifier::MTextMagnifier(const QGraphicsItem &sourceItem)
     : MStylableWidget(0),
       sourceItem(sourceItem)
 {
-    overlay.setFlag(QGraphicsItem::ItemHasNoContents, true);
     setParentItem(&overlay);
 }
 
@@ -44,10 +44,12 @@ void MTextMagnifier::appear()
 {
     // Appear in the scene of the source item.
     overlay.appear(sourceItem.scene());
+    overlay.grabGesture(Qt::PanGesture);
 }
 
 void MTextMagnifier::disappear()
 {
+    overlay.ungrabGesture(Qt::PanGesture);
     overlay.disappear();
 }
 
@@ -58,7 +60,7 @@ void MTextMagnifier::setMagnifiedPosition(const QPointF &sourceItemPos)
 
 bool MTextMagnifier::isAppeared() const
 {
-    return (overlay.sceneWindowState() != MSceneWindow::Disappeared);
+    return overlay.isAppeared();
 }
 
 void MTextMagnifier::drawContents(QPainter *painter,
@@ -97,11 +99,14 @@ void MTextMagnifier::drawContents(QPainter *painter,
     const_cast<QGraphicsItem *>(&sourceItem)->paint(&offscreenPainter, &sourceItemOption);
 
     offscreenPainter.resetTransform();
-    offscreenPainter.setCompositionMode(QPainter::CompositionMode_DestinationIn);
-    offscreenPainter.drawPixmap(offscreenSurface->rect(), *style()->magnifierMask());
-
-    offscreenPainter.setCompositionMode(QPainter::CompositionMode_DestinationOver);
-    offscreenPainter.drawPixmap(offscreenSurface->rect(), *style()->magnifierFrame());
+    if (style()->magnifierMask()) {
+        offscreenPainter.setCompositionMode(QPainter::CompositionMode_DestinationIn);
+        offscreenPainter.drawPixmap(offscreenSurface->rect(), *style()->magnifierMask());
+    }
+    if (style()->magnifierFrame()) {
+        offscreenPainter.setCompositionMode(QPainter::CompositionMode_DestinationOver);
+        offscreenPainter.drawPixmap(offscreenSurface->rect(), *style()->magnifierFrame());
+    }
     offscreenPainter.end();
 
     // Paint the result to screen
@@ -115,6 +120,9 @@ void MTextMagnifier::drawContents(QPainter *painter,
 
 void MTextMagnifier::applyStyle()
 {
+    if (!style()->magnifierFrame()) {
+        return;
+    }
     // Update bounding rectangle.
     prepareGeometryChange();
     QSize magnifierSize(style()->magnifierFrame()->size());
@@ -144,3 +152,35 @@ void MTextMagnifier::prepareOffscreenSurface(const QSize &size)
     }
     offscreenSurface.reset(new QPixmap(size));
 }
+
+
+// Magnifier overlay widget
+
+MagnifierOverlay::MagnifierOverlay()
+{
+    setFlag(QGraphicsItem::ItemHasNoContents, true);
+
+    // Occupy whole screen to be able to catch panning gestures. The size does not really matter
+    // as long as it covers whole screen in portrait and landscape.
+    setManagedManually(true);
+    const QSizeF visibleSceneSize = sceneManager()->visibleSceneSize(M::Landscape);
+    const qreal size = qMax<qreal>(visibleSceneSize.width(), visibleSceneSize.height());
+    setPreferredSize(size, size);
+}
+
+bool MagnifierOverlay::isAppeared() const
+{
+    return sceneWindowState() != MSceneWindow::Disappeared;
+}
+
+void MagnifierOverlay::panGestureEvent(QGestureEvent *event, QPanGesture *panGesture)
+{
+    // Accept gesture if magnifier is appeared. This is done to prevent panning of
+    // application page but will of course prevent other uses of pan gestures as well.
+    if (panGesture->state() == Qt::GestureStarted
+        && isAppeared()) {
+        event->accept(panGesture);
+    } else {
+        event->ignore(panGesture);
+    }
+}
diff --git a/src/views/mtextmagnifier.h b/src/views/mtextmagnifier.h
index 1cfb9159..4a95c5cd 100644
--- a/src/views/mtextmagnifier.h
+++ b/src/views/mtextmagnifier.h
@@ -24,7 +24,24 @@
 
 #include <MOverlay>
 
+#include <MSceneManager>
+#include <QDebug>
+#include <QPanGesture>
+
 //! \internal
+
+//! Overlay widget to allow magnifier to stay on top of other widgets.
+class MagnifierOverlay : public MOverlay
+{
+public:
+    MagnifierOverlay();
+    bool isAppeared() const;
+
+protected:
+    virtual void panGestureEvent(QGestureEvent *event, QPanGesture *panGesture);
+    friend class Ut_MTextMagnifier;
+};
+
 /*! \brief Magnifier widget to magnify text.
  *
  *  The class magnifies contents of a certain source item.
@@ -74,10 +91,13 @@ private:
     QScopedPointer<QPixmap> offscreenSurface;
     QScopedPointer<QBitmap> mask;
 
-    MOverlay overlay;
+    MagnifierOverlay overlay;
 
     M_STYLABLE_WIDGET(MTextMagnifierStyle)
+
+    friend class Ut_MTextMagnifier;
 };
+
 //! \internal_end
 
 #endif
diff --git a/tests/tests.pro b/tests/tests.pro
index 4befe738..f8893d40 100644
--- a/tests/tests.pro
+++ b/tests/tests.pro
@@ -75,6 +75,7 @@ SUBDIRS     =  \
      ut_msliderview \
     ut_mtextedit \
     ut_mtexteditview \
+    ut_mtextmagnifier \
      ut_mthemedaemonprotocol \
     ut_mtheme \
     ut_mtoolbar \
diff --git a/tests/ut_mtextmagnifier/.gitignore b/tests/ut_mtextmagnifier/.gitignore
new file mode 100644
index 00000000..2f9f8340
--- /dev/null
+++ b/tests/ut_mtextmagnifier/.gitignore
@@ -0,0 +1,2 @@
+ut_mtextmagnifier
+
diff --git a/tests/ut_mtextmagnifier/mtextmagnifierstyle.h b/tests/ut_mtextmagnifier/mtextmagnifierstyle.h
new file mode 100644
index 00000000..3730b0d7
--- /dev/null
+++ b/tests/ut_mtextmagnifier/mtextmagnifierstyle.h
@@ -0,0 +1,31 @@
+#ifndef MTEXTMAGNIFIERSTYLE_H
+#define MTEXTMAGNIFIERSTYLE_H
+
+#include <MWidgetStyle>
+
+class QString;
+class MWidgetController;
+
+class MTextMagnifierStyle
+{
+public:
+    qreal magnification() const { return 0.0; }
+    QPixmap *magnifierMask() const { return 0; }
+    QPixmap *magnifierFrame() const { return 0; }
+    QPointF visualOffset() const { return QPointF(); }
+
+}static gMagnifierStyle;
+
+class MTextMagnifierStyleContainer : public MWidgetStyleContainer
+{
+public:
+    void initialize(const QString &, const QString &, const MWidgetController *){}
+    void setModeDefault() const {}
+    const MTextMagnifierStyle* operator->() const
+    {
+        return &gMagnifierStyle;
+    }
+};
+
+
+#endif // MTEXTMAGNIFIERSTYLE_H
diff --git a/tests/ut_mtextmagnifier/ut_mtextmagnifier.cpp b/tests/ut_mtextmagnifier/ut_mtextmagnifier.cpp
new file mode 100644
index 00000000..4e8a13c2
--- /dev/null
+++ b/tests/ut_mtextmagnifier/ut_mtextmagnifier.cpp
@@ -0,0 +1,117 @@
+/***************************************************************************
+**
+** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (directui@nokia.com)
+**
+** This file is part of libmeegotouch.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at directui@nokia.com.
+**
+** This library is free software; you can redistribute it and/or
+** modify it under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation
+** and appearing in the file LICENSE.LGPL included in the packaging
+** of this file.
+**
+****************************************************************************/
+
+#include "ut_mtextmagnifier.h"
+#include "views/mtextmagnifier.h"
+
+#include <QEvent>
+#include <QGraphicsWidget>
+#include <QMetaType>
+#include <QPainter>
+#include <QPanGesture>
+#include <QSignalSpy>
+
+#include <MApplication>
+#include <MApplicationWindow>
+#include <MCancelEvent>
+#include <MScene>
+
+namespace {
+    Qt::GestureState gGestureState = Qt::GestureStarted;
+}
+
+Qt::GestureState QGesture::state() const
+{
+    return gGestureState;
+}
+
+void Ut_MTextMagnifier::initTestCase()
+{
+    static int dummyArgc = 1;
+    static char *dummyArgv[1] = { (char *) "./ut_mtextmagnifier" };
+    MApplication::setLoadMInputContext(false);
+    m_app = new MApplication(dummyArgc, dummyArgv);
+    m_appWindow = new MApplicationWindow;
+
+    magnifiedWidget = new QGraphicsWidget;
+    m_appWindow->scene()->addItem(magnifiedWidget);
+}
+
+void Ut_MTextMagnifier::cleanupTestCase()
+{
+    delete magnifiedWidget;
+    magnifiedWidget = 0;
+    delete m_appWindow;
+    m_appWindow = 0;
+    delete m_app;
+    m_app = 0;
+}
+
+
+void Ut_MTextMagnifier::init()
+{
+    subject = new MTextMagnifier(*magnifiedWidget);
+}
+
+
+void Ut_MTextMagnifier::cleanup()
+{
+    delete subject;
+    subject = 0;
+}
+
+void Ut_MTextMagnifier::testMagnifierConsumesPanGesture_data()
+{
+    QTest::addColumn<Qt::GestureState>("gestureState");
+    QTest::addColumn<bool>("wasConsumed");
+
+    // This is needs to work to prevent panning while magnifier is shown.
+    QTest::newRow("gesture started") << Qt::GestureStarted << true;
+
+    // Other gesture states should be ignored.
+    QTest::newRow("gesture canceled") << Qt::GestureCanceled << false;
+    QTest::newRow("gesture updated") << Qt::GestureUpdated << false;
+    QTest::newRow("gesture finished") << Qt::GestureFinished << false;
+}
+
+void Ut_MTextMagnifier::testMagnifierConsumesPanGesture()
+{
+    QFETCH(Qt::GestureState, gestureState);
+    QFETCH(bool, wasConsumed);
+
+    subject->appear();
+    QVERIFY(subject->isAppeared());
+
+    // Create gesture object and put it inside an event.
+    QPanGesture panGesture;
+    gGestureState = gestureState;
+
+    QList<QGesture *> gestures;
+    gestures << &panGesture;
+    QGestureEvent event(gestures);
+    event.setAccepted(Qt::PanGesture, false);
+
+    // It is actually overlay who gets the event.
+    subject->overlay.gestureEvent(&event);
+
+    QCOMPARE(event.isAccepted(Qt::PanGesture), wasConsumed);
+}
+
+QTEST_APPLESS_MAIN(Ut_MTextMagnifier)
+
diff --git a/tests/ut_mtextmagnifier/ut_mtextmagnifier.h b/tests/ut_mtextmagnifier/ut_mtextmagnifier.h
new file mode 100644
index 00000000..d1c0acb8
--- /dev/null
+++ b/tests/ut_mtextmagnifier/ut_mtextmagnifier.h
@@ -0,0 +1,52 @@
+/***************************************************************************
+**
+** Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies).
+** All rights reserved.
+** Contact: Nokia Corporation (directui@nokia.com)
+**
+** This file is part of libmeegotouch.
+**
+** If you have questions regarding the use of this file, please contact
+** Nokia at directui@nokia.com.
+**
+** This library is free software; you can redistribute it and/or
+** modify it under the terms of the GNU Lesser General Public
+** License version 2.1 as published by the Free Software Foundation
+** and appearing in the file LICENSE.LGPL included in the packaging
+** of this file.
+**
+****************************************************************************/
+
+#ifndef UT_MTEXTMAGNIFIER_H
+#define UT_MTEXTMAGNIFIER_H
+
+#include <QObject>
+#include <QtTest/QtTest>
+
+class MApplication;
+class MApplicationWindow;
+class MTextMagnifier;
+class QGraphicsWidget;
+
+class Ut_MTextMagnifier : public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void init();
+    void cleanup();
+    void initTestCase();
+    void cleanupTestCase();
+
+    void testMagnifierConsumesPanGesture_data();
+    void testMagnifierConsumesPanGesture();
+
+private:
+    MApplication *m_app;
+    MApplicationWindow *m_appWindow;
+    MTextMagnifier *subject;
+    QGraphicsWidget *magnifiedWidget;
+};
+
+#endif
+
diff --git a/tests/ut_mtextmagnifier/ut_mtextmagnifier.pro b/tests/ut_mtextmagnifier/ut_mtextmagnifier.pro
new file mode 100644
index 00000000..c8cb03b4
--- /dev/null
+++ b/tests/ut_mtextmagnifier/ut_mtextmagnifier.pro
@@ -0,0 +1,15 @@
+include(../common_top.pri)
+TARGET = ut_mtextmagnifier
+
+INCLUDEPATH += $$MSRCDIR
+
+SOURCES += \
+    ut_mtextmagnifier.cpp \
+    $$MSRCDIR/views/mtextmagnifier.cpp
+
+HEADERS += \
+    ut_mtextmagnifier.h \
+    mtextmagnifierstyle.h \
+    $$MSRCDIR/views/mtextmagnifier.h
+
+include(../common_bot.pri)