Add a function to change non-client area rendering policy

Documentation and a manual test are added at the same time.

Change-Id: I1e70e9b01fb13d0e67559024531f9ad015849032
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>

10 files changed, 252 insertions, 15 deletions

diff --git a/src/imports/winextras/plugins.qmltypes b/src/imports/winextras/plugins.qmltypes
index 2c4c390..fff1181 100644
--- a/src/imports/winextras/plugins.qmltypes
+++ b/src/imports/winextras/plugins.qmltypes
@@ -26,6 +26,7 @@ Module {
         Property { name: "excludedFromPeek"; type: "bool" }
         Property { name: "peekDisallowed"; type: "bool" }
         Property { name: "flip3DPolicy"; type: "QQuickWin::WindowFlip3DPolicy" }
+        Property { name: "nonClientAreaRenderingPolicy"; type: "QQuickWin::WindowNonClientRenderingPolicy" }
     }
     Component {
         name: "QQuickJumpList"
@@ -144,6 +145,14 @@ Module {
                 "FlipExcludeAbove": 2
             }
         }
+        Enum {
+            name: "WindowNonClientRenderingPolicy"
+            values: {
+                "NonClientRenderingUseWindowStyle": 0,
+                "NonClientRenderingDisabled": 1,
+                "NonClientRenderingEnabled": 2
+            }
+        }
     }
     Component {
         name: "QWinTaskbarProgress"
diff --git a/src/imports/winextras/qquickdwmfeatures.cpp b/src/imports/winextras/qquickdwmfeatures.cpp
index a7ca158..124d957 100644
--- a/src/imports/winextras/qquickdwmfeatures.cpp
+++ b/src/imports/winextras/qquickdwmfeatures.cpp
@@ -293,6 +293,32 @@ void QQuickDwmFeatures::setFlip3DPolicy(QQuickWin::WindowFlip3DPolicy policy)
     emit flip3DPolicyChanged();
 }
 
+/*!
+    \qmlproperty QtWin::WindowNonClientRenderingPolicy DwmFeatures::nonClientAreaRenderingPolicy
+
+    The current non-client area rendering policy for the window.
+ */
+QQuickWin::WindowNonClientRenderingPolicy QQuickDwmFeatures::nonClientAreaRenderingPolicy() const
+{
+    Q_D(const QQuickDwmFeatures);
+    if (window())
+        return static_cast<QQuickWin::WindowNonClientRenderingPolicy>(QtWin::windowNonClientAreaRenderingPolicy(window()));
+    else
+        return d->nonClientRenderingPolicy;
+}
+
+void QQuickDwmFeatures::setNonClientAreaRenderingPolicy(QQuickWin::WindowNonClientRenderingPolicy policy)
+{
+    Q_D(QQuickDwmFeatures);
+    if (d->nonClientRenderingPolicy == policy)
+        return;
+
+    d->nonClientRenderingPolicy = policy;
+    if (window())
+        QtWin::setWindowNonClientAreaRenderingPolicy(window(), static_cast<QtWin::WindowNonClientRenderingPolicy>(d->nonClientRenderingPolicy));
+    emit nonClientAreaRenderingPolicyChanged();
+}
+
 bool QQuickDwmFeatures::eventFilter(QObject *object, QEvent *event)
 {
     Q_D(QQuickDwmFeatures);
@@ -349,6 +375,7 @@ void QQuickDwmFeaturesPrivate::updateAll()
         QtWin::setWindowExcludedFromPeek(w, peekExcluded);
         QtWin::setWindowDisallowPeek(w, peekDisallowed);
         QtWin::setWindowFlip3DPolicy(w, static_cast<QtWin::WindowFlip3DPolicy>(flipPolicy));
+        QtWin::setWindowNonClientAreaRenderingPolicy(w, static_cast<QtWin::WindowNonClientRenderingPolicy>(nonClientRenderingPolicy));
         if (blurBehindEnabled)
             QtWin::enableBlurBehindWindow(w);
         else
diff --git a/src/imports/winextras/qquickdwmfeatures_p.h b/src/imports/winextras/qquickdwmfeatures_p.h
index d98aa00..3887d24 100644
--- a/src/imports/winextras/qquickdwmfeatures_p.h
+++ b/src/imports/winextras/qquickdwmfeatures_p.h
@@ -77,6 +77,7 @@ class QQuickDwmFeatures : public QQuickItem
     Q_PROPERTY(bool excludedFromPeek READ isExcludedFromPeek WRITE setExcludedFromPeek NOTIFY excludedFromPeekChanged)
     Q_PROPERTY(bool peekDisallowed READ isPeekDisallowed WRITE setPeekDisallowed NOTIFY peekDisallowedChanged)
     Q_PROPERTY(QQuickWin::WindowFlip3DPolicy flip3DPolicy READ flip3DPolicy WRITE setFlip3DPolicy NOTIFY flip3DPolicyChanged)
+    Q_PROPERTY(QQuickWin::WindowNonClientRenderingPolicy nonClientAreaRenderingPolicy READ nonClientAreaRenderingPolicy WRITE setNonClientAreaRenderingPolicy NOTIFY nonClientAreaRenderingPolicyChanged)
 
 public:
     explicit QQuickDwmFeatures(QQuickItem *parent = nullptr);
@@ -105,6 +106,8 @@ public:
     void setPeekDisallowed(bool disallow);
     QQuickWin::WindowFlip3DPolicy flip3DPolicy() const;
     void setFlip3DPolicy(QQuickWin::WindowFlip3DPolicy policy);
+    QQuickWin::WindowNonClientRenderingPolicy nonClientAreaRenderingPolicy() const;
+    void setNonClientAreaRenderingPolicy(QQuickWin::WindowNonClientRenderingPolicy policy);
 
     bool eventFilter(QObject *, QEvent *) Q_DECL_OVERRIDE;
 
@@ -123,6 +126,7 @@ Q_SIGNALS:
     void excludedFromPeekChanged();
     void peekDisallowedChanged();
     void flip3DPolicyChanged();
+    void nonClientAreaRenderingPolicyChanged();
 
 protected:
     void itemChange(ItemChange, const ItemChangeData &) Q_DECL_OVERRIDE;
diff --git a/src/imports/winextras/qquickdwmfeatures_p_p.h b/src/imports/winextras/qquickdwmfeatures_p_p.h
index 4ec1244..acf9dd6 100644
--- a/src/imports/winextras/qquickdwmfeatures_p_p.h
+++ b/src/imports/winextras/qquickdwmfeatures_p_p.h
@@ -70,6 +70,7 @@ public:
     bool peekDisallowed = false;
     bool peekExcluded = false;
     QQuickWin::WindowFlip3DPolicy flipPolicy = QQuickWin::FlipDefault;
+    QQuickWin::WindowNonClientRenderingPolicy nonClientRenderingPolicy = QQuickWin::NonClientRenderingUseWindowStyle;
     QColor originalSurfaceColor;
 
     void updateAll();
diff --git a/src/imports/winextras/qquickwin_p.h b/src/imports/winextras/qquickwin_p.h
index 0f4e510..4ed9015 100644
--- a/src/imports/winextras/qquickwin_p.h
+++ b/src/imports/winextras/qquickwin_p.h
@@ -77,6 +77,14 @@ public:
         FlipExcludeAbove = QtWin::FlipExcludeAbove
     };
     Q_ENUM(WindowFlip3DPolicy)
+
+    enum WindowNonClientRenderingPolicy
+    {
+        NonClientRenderingUseWindowStyle = QtWin::NonClientRenderingUseWindowStyle,
+        NonClientRenderingDisabled = QtWin::NonClientRenderingDisabled,
+        NonClientRenderingEnabled = QtWin::NonClientRenderingEnabled
+    };
+    Q_ENUM(WindowNonClientRenderingPolicy)
 };
 
 QT_END_NAMESPACE
diff --git a/src/winextras/qwinfunctions.cpp b/src/winextras/qwinfunctions.cpp
index 4dcf8f0..68f2c99 100644
--- a/src/winextras/qwinfunctions.cpp
+++ b/src/winextras/qwinfunctions.cpp
@@ -1640,6 +1640,69 @@ QtWin::WindowFlip3DPolicy QtWin::windowFlip3DPolicy(QWindow *window)
     return policy;
 }
 
+/*!
+    \since 6.0
+
+    Sets the non-client area rendering policy \a policy for the specified \a window.
+
+    \note Disabling non-client area rendering will cause any previous calls to
+    QtWin::enableBlurBehindWindow() or to QtWin::extendFrameIntoClientArea() to be disabled.
+ */
+void QtWin::setWindowNonClientAreaRenderingPolicy(QWindow *window, QtWin::WindowNonClientRenderingPolicy policy)
+{
+    Q_ASSERT_X(window, Q_FUNC_INFO, "window is null");
+
+    HWND handle = reinterpret_cast<HWND>(window->winId());
+
+    DWORD value = DWMNCRP_USEWINDOWSTYLE;
+
+    switch (policy) {
+    default :
+    case NonClientRenderingUseWindowStyle :
+        break;
+    case NonClientRenderingDisabled :
+        value = DWMNCRP_DISABLED;
+        break;
+    case NonClientRenderingEnabled :
+        value = DWMNCRP_ENABLED;
+        break;
+    }
+
+    QtDwmApiDll::setWindowAttribute(handle, DWMWA_NCRENDERING_POLICY, value);
+}
+
+/*!
+    \fn QtWin::WindowNonClientRenderingPolicy QtWin::windowNonClientAreaRenderingPolicy(QWidget *window)
+    \since 6.0
+    \overload QtWin::windowNonClientAreaRenderingPolicy()
+ */
+
+/*!
+    \since 6.0
+
+    Returns the current non-client area rendering policy for the specified \a window.
+ */
+QtWin::WindowNonClientRenderingPolicy QtWin::windowNonClientAreaRenderingPolicy(QWindow *window)
+{
+    Q_ASSERT_X(window, Q_FUNC_INFO, "window is null");
+
+    const auto value =
+        QtDwmApiDll::windowAttribute<DWORD>(reinterpret_cast<HWND>(window->winId()),
+                                            DWMWA_NCRENDERING_POLICY, DWORD(DWMNCRP_USEWINDOWSTYLE));
+    WindowNonClientRenderingPolicy policy = NonClientRenderingUseWindowStyle;
+    switch (value) {
+    case DWMNCRP_DISABLED :
+        policy = NonClientRenderingDisabled;
+        break;
+    case DWMNCRP_ENABLED :
+        policy = NonClientRenderingEnabled;
+        break;
+    default :
+        break;
+    }
+    return policy;
+}
+
 void qt_ExtendFrameIntoClientArea(QWindow *window, int left, int top, int right, int bottom)
 {
     QWinEventFilter::setup();
@@ -1659,7 +1722,9 @@ void qt_ExtendFrameIntoClientArea(QWindow *window, int left, int top, int right,
     using the \a left, \a top, \a right, and \a bottom margin values.
 
     Pass -1 as values for any of the four margins to fully extend the frame,
-    creating a \e {sheet of glass} effect.
+    creating a \e {sheet of glass} effect. If it doesn't work, change
+    non-client area rendering policy to QtWin::NonClientRenderingEnabled and
+    try again.
 
     If you want the extended frame to act like a standard window border, you
     should handle that yourself.
@@ -1667,7 +1732,7 @@ void qt_ExtendFrameIntoClientArea(QWindow *window, int left, int top, int right,
     \note Qt::WA_NoSystemBackground must not be set on widgets for
     extendFrameIntoClientArea() to work.
 
-    \sa resetExtendedFrame()
+    \sa resetExtendedFrame(), setWindowNonClientAreaRenderingPolicy()
  */
 void QtWin::extendFrameIntoClientArea(QWindow *window, int left, int top, int right, int bottom)
 {
@@ -2041,4 +2106,32 @@ void QtWin::taskbarDeleteTab(QWindow *window)
     \sa setWindowFlip3DPolicy()
  */
 
+/*!
+    \enum QtWin::WindowNonClientRenderingPolicy
+
+    \since 6.0
+
+    This enum type specifies the non-client area rendering policy.
+
+    \value  NonClientRenderingUseWindowStyle
+            The non-client rendering area is rendered based on the window
+            style.
+
+    \value  NonClientRenderingDisabled
+            The non-client area rendering is disabled and the window style
+            is ignored.
+            Note that disabling non-client area rendering will cause any
+            previous calls to QtWin::enableBlurBehindWindow() or to
+            QtWin::extendFrameIntoClientArea() to be disabled.
+
+    \value  NonClientRenderingEnabled
+            The non-client area rendering is enabled and the window style
+            is ignored.
+            If you want to bring frame shadow back to a frameless window,
+            enable this policy and call QtWin::extendFrameIntoClientArea()
+            with a negative height.
+
+    \sa setWindowNonClientAreaRenderingPolicy()
+ */
+
 QT_END_NAMESPACE
diff --git a/src/winextras/qwinfunctions.h b/src/winextras/qwinfunctions.h
index ef2aece..8f27a6f 100644
--- a/src/winextras/qwinfunctions.h
+++ b/src/winextras/qwinfunctions.h
@@ -77,6 +77,13 @@ namespace QtWin
         FlipExcludeAbove
     };
 
+    enum WindowNonClientRenderingPolicy
+    {
+        NonClientRenderingUseWindowStyle,
+        NonClientRenderingDisabled,
+        NonClientRenderingEnabled
+    };
+
     Q_WINEXTRAS_EXPORT HBITMAP createMask(const QBitmap &bitmap);
     Q_WINEXTRAS_EXPORT HBITMAP toHBITMAP(const QPixmap &p, HBitmapFormat format = HBitmapNoAlpha);
     Q_WINEXTRAS_EXPORT QPixmap fromHBITMAP(HBITMAP bitmap, HBitmapFormat format = HBitmapNoAlpha);
@@ -100,6 +107,8 @@ namespace QtWin
     Q_WINEXTRAS_EXPORT bool isWindowPeekDisallowed(QWindow *window);
     Q_WINEXTRAS_EXPORT void setWindowFlip3DPolicy(QWindow *window, WindowFlip3DPolicy policy);
     Q_WINEXTRAS_EXPORT WindowFlip3DPolicy windowFlip3DPolicy(QWindow *);
+    Q_WINEXTRAS_EXPORT void setWindowNonClientAreaRenderingPolicy(QWindow *window, WindowNonClientRenderingPolicy policy);
+    Q_WINEXTRAS_EXPORT WindowNonClientRenderingPolicy windowNonClientAreaRenderingPolicy(QWindow *);
 
     Q_WINEXTRAS_EXPORT void extendFrameIntoClientArea(QWindow *window, int left, int top, int right, int bottom);
     Q_WINEXTRAS_EXPORT void extendFrameIntoClientArea(QWindow *window, const QMargins &margins);
@@ -155,10 +164,20 @@ namespace QtWin
 
     inline WindowFlip3DPolicy windowFlip3DPolicy(QWidget *window)
     {
-        if (!window->windowHandle())
-            return FlipDefault;
-        else
-            return windowFlip3DPolicy(window->windowHandle());
+        auto handle = window->windowHandle();
+        return handle ? windowFlip3DPolicy(handle) : FlipDefault;
+    }
+
+    inline void setWindowNonClientAreaRenderingPolicy(QWidget *window, WindowNonClientRenderingPolicy policy)
+    {
+        window->createWinId();
+        setWindowNonClientAreaRenderingPolicy(window->windowHandle(), policy);
+    }
+
+    inline WindowNonClientRenderingPolicy windowNonClientAreaRenderingPolicy(QWidget *window)
+    {
+        auto handle = window->windowHandle();
+        return handle ? windowNonClientAreaRenderingPolicy(handle) : NonClientRenderingUseWindowStyle;
     }
 
     inline void extendFrameIntoClientArea(QWidget *window, const QMargins &margins)
diff --git a/tests/manual/dwmfeatures/testwidget.cpp b/tests/manual/dwmfeatures/testwidget.cpp
index 09b25ac..e289946 100644
--- a/tests/manual/dwmfeatures/testwidget.cpp
+++ b/tests/manual/dwmfeatures/testwidget.cpp
@@ -40,11 +40,14 @@ TestWidget::TestWidget(QWidget *parent) :
 {
     ui->setupUi(this);
 
-    connect(ui->btnPeekDisallow,  &QAbstractButton::clicked, this, &TestWidget::onDisallowPeekClicked);
-    connect(ui->btnPeekExclude,   &QAbstractButton::clicked, this, &TestWidget::onExcludeFromPeekClicked);
-    connect(ui->radioFlipDefault, &QAbstractButton::clicked, this, &TestWidget::onFlip3DPolicyChanged);
-    connect(ui->radioFlipAbove,   &QAbstractButton::clicked, this, &TestWidget::onFlip3DPolicyChanged);
-    connect(ui->radioFlipBelow,   &QAbstractButton::clicked, this, &TestWidget::onFlip3DPolicyChanged);
+    connect(ui->btnPeekDisallow,         &QAbstractButton::clicked, this, &TestWidget::onDisallowPeekClicked);
+    connect(ui->btnPeekExclude,          &QAbstractButton::clicked, this, &TestWidget::onExcludeFromPeekClicked);
+    connect(ui->radioFlipDefault,        &QAbstractButton::clicked, this, &TestWidget::onFlip3DPolicyChanged);
+    connect(ui->radioFlipAbove,          &QAbstractButton::clicked, this, &TestWidget::onFlip3DPolicyChanged);
+    connect(ui->radioFlipBelow,          &QAbstractButton::clicked, this, &TestWidget::onFlip3DPolicyChanged);
+    connect(ui->radioNcrpUseWindowStyle, &QAbstractButton::clicked, this, &TestWidget::onNonClientAreaRenderingPolicyChanged);
+    connect(ui->radioNcrpDisable,        &QAbstractButton::clicked, this, &TestWidget::onNonClientAreaRenderingPolicyChanged);
+    connect(ui->radioNcrpEnable,         &QAbstractButton::clicked, this, &TestWidget::onNonClientAreaRenderingPolicyChanged);
     connect(ui->btnFrameReset,    &QAbstractButton::clicked, this, &TestWidget::onResetGlassFrameClicked);
     connect(ui->frameTop, QOverload<int>::of(&QSpinBox::valueChanged),
             this, &TestWidget::onGlassMarginsChanged);
@@ -106,6 +109,18 @@ void TestWidget::onFlip3DPolicyChanged()
     QtWin::setWindowFlip3DPolicy(this, policy);
 }
 
+void TestWidget::onNonClientAreaRenderingPolicyChanged()
+{
+    QtWin::WindowNonClientRenderingPolicy policy;
+    if (ui->radioNcrpDisable->isChecked())
+        policy = QtWin::NonClientRenderingDisabled;
+    else if (ui->radioNcrpEnable->isChecked())
+        policy = QtWin::NonClientRenderingEnabled;
+    else
+        policy = QtWin::NonClientRenderingUseWindowStyle;
+    QtWin::setWindowNonClientAreaRenderingPolicy(this, policy);
+}
+
 void TestWidget::onGlassMarginsChanged()
 {
     if (!QtWin::isCompositionEnabled())
diff --git a/tests/manual/dwmfeatures/testwidget.h b/tests/manual/dwmfeatures/testwidget.h
index 137e8ce..70c39c6 100644
--- a/tests/manual/dwmfeatures/testwidget.h
+++ b/tests/manual/dwmfeatures/testwidget.h
@@ -60,6 +60,7 @@ private slots:
     void onDisallowPeekClicked();
     void onExcludeFromPeekClicked();
     void onFlip3DPolicyChanged();
+    void onNonClientAreaRenderingPolicyChanged();
     void onGlassMarginsChanged();
     void onResetGlassFrameClicked();
 };
diff --git a/tests/manual/dwmfeatures/testwidget.ui b/tests/manual/dwmfeatures/testwidget.ui
index 329ba61..2ef17d8 100644
--- a/tests/manual/dwmfeatures/testwidget.ui
+++ b/tests/manual/dwmfeatures/testwidget.ui
@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>569</width>
-    <height>331</height>
+    <height>451</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -31,7 +31,16 @@
         <property name="spacing">
          <number>3</number>
         </property>
-        <property name="margin">
+        <property name="leftMargin">
+         <number>4</number>
+        </property>
+        <property name="topMargin">
+         <number>4</number>
+        </property>
+        <property name="rightMargin">
+         <number>4</number>
+        </property>
+        <property name="bottomMargin">
          <number>4</number>
         </property>
         <item>
@@ -155,7 +164,16 @@
         <property name="spacing">
          <number>3</number>
         </property>
-        <property name="margin">
+        <property name="leftMargin">
+         <number>4</number>
+        </property>
+        <property name="topMargin">
+         <number>4</number>
+        </property>
+        <property name="rightMargin">
+         <number>4</number>
+        </property>
+        <property name="bottomMargin">
          <number>4</number>
         </property>
         <item>
@@ -186,6 +204,39 @@
       </widget>
      </item>
      <item>
+      <widget class="QGroupBox" name="groupBox">
+       <property name="title">
+        <string>Non-client area rendering</string>
+       </property>
+       <layout class="QVBoxLayout" name="verticalLayout_3">
+        <item>
+         <widget class="QRadioButton" name="radioNcrpUseWindowStyle">
+          <property name="text">
+           <string>Use window style</string>
+          </property>
+          <property name="checked">
+           <bool>true</bool>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QRadioButton" name="radioNcrpDisable">
+          <property name="text">
+           <string>Disable</string>
+          </property>
+         </widget>
+        </item>
+        <item>
+         <widget class="QRadioButton" name="radioNcrpEnable">
+          <property name="text">
+           <string>Enable</string>
+          </property>
+         </widget>
+        </item>
+       </layout>
+      </widget>
+     </item>
+     <item>
       <widget class="QGroupBox" name="groupBox_3">
        <property name="title">
         <string>Glass frame</string>
@@ -197,7 +248,16 @@
         <property name="verticalSpacing">
          <number>3</number>
         </property>
-        <property name="margin">
+        <property name="leftMargin">
+         <number>4</number>
+        </property>
+        <property name="topMargin">
+         <number>4</number>
+        </property>
+        <property name="rightMargin">
+         <number>4</number>
+        </property>
+        <property name="bottomMargin">
          <number>4</number>
         </property>
         <item row="0" column="0">