ColorDialog & FontDialog: use widgets as a fallback

This makes these dialogs available on Windows and KDE. One more reason
to keep the module experimental. In the long run, platforms should
implement QPA dialogs so that we can remove the undesired dependency.

Also simple instance creation tests are included to make sure it
won't crash with non-QApplication apps.

Change-Id: Ib4dabe7b656a1aa1f114052a3f57c9b1232ff27f
Reviewed-by: J-P Nurmi <jpnurmi@qt.io>

7 files changed, 483 insertions, 0 deletions

diff --git a/src/imports/platform/widgets/qwidgetplatformcolordialog.cpp b/src/imports/platform/widgets/qwidgetplatformcolordialog.cpp
new file mode 100644
index 00000000..4dd0895d
--- /dev/null
+++ b/src/imports/platform/widgets/qwidgetplatformcolordialog.cpp
@@ -0,0 +1,98 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt Labs Platform module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qwidgetplatformcolordialog_p.h"
+#include "qwidgetplatformdialog_p.h"
+#include "qwidgetplatform_p.h"
+
+#include <QtWidgets/qcolordialog.h>
+
+QT_BEGIN_NAMESPACE
+
+QWidgetPlatformColorDialog::QWidgetPlatformColorDialog(QObject *parent)
+{
+    setParent(parent);
+
+    static bool available = QWidgetPlatform::isAvailable("color dialog");
+    if (available) {
+        m_dialog.reset(new QColorDialog);
+        connect(m_dialog.data(), &QColorDialog::accepted, this, &QPlatformDialogHelper::accept);
+        connect(m_dialog.data(), &QColorDialog::rejected, this, &QPlatformDialogHelper::reject);
+        connect(m_dialog.data(), &QColorDialog::colorSelected, this, &QPlatformColorDialogHelper::colorSelected);
+        connect(m_dialog.data(), &QColorDialog::currentColorChanged, this, &QPlatformColorDialogHelper::currentColorChanged);
+    }
+}
+
+QWidgetPlatformColorDialog::~QWidgetPlatformColorDialog()
+{
+}
+
+QColor QWidgetPlatformColorDialog::currentColor() const
+{
+    return m_dialog ? m_dialog->currentColor() : QColor();
+}
+
+void QWidgetPlatformColorDialog::setCurrentColor(const QColor &color)
+{
+    if (m_dialog)
+        m_dialog->setCurrentColor(color);
+}
+
+void QWidgetPlatformColorDialog::exec()
+{
+    if (m_dialog)
+        m_dialog->exec();
+}
+
+bool QWidgetPlatformColorDialog::show(Qt::WindowFlags flags, Qt::WindowModality modality, QWindow *parent)
+{
+    if (!m_dialog)
+        return false;
+
+    QSharedPointer<QColorDialogOptions> options = QPlatformColorDialogHelper::options();
+    m_dialog->setWindowTitle(options->windowTitle());
+    m_dialog->setOptions(static_cast<QColorDialog::ColorDialogOptions>(int(options->options())));
+
+    return QWidgetPlatformDialog::show(m_dialog.data(), flags, modality, parent);
+}
+
+void QWidgetPlatformColorDialog::hide()
+{
+    if (m_dialog)
+        m_dialog->hide();
+}
+
+QT_END_NAMESPACE
diff --git a/src/imports/platform/widgets/qwidgetplatformcolordialog_p.h b/src/imports/platform/widgets/qwidgetplatformcolordialog_p.h
new file mode 100644
index 00000000..14bbcd1f
--- /dev/null
+++ b/src/imports/platform/widgets/qwidgetplatformcolordialog_p.h
@@ -0,0 +1,78 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt Labs Platform module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QWIDGETPLATFORMCOLORDIALOG_P_H
+#define QWIDGETPLATFORMCOLORDIALOG_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtGui/qpa/qplatformdialoghelper.h>
+
+QT_BEGIN_NAMESPACE
+
+class QColorDialog;
+
+class QWidgetPlatformColorDialog : public QPlatformColorDialogHelper
+{
+    Q_OBJECT
+
+public:
+    explicit QWidgetPlatformColorDialog(QObject *parent = nullptr);
+    ~QWidgetPlatformColorDialog();
+
+    QColor currentColor() const override;
+    void setCurrentColor(const QColor &color) override;
+
+    void exec() override;
+    bool show(Qt::WindowFlags flags, Qt::WindowModality modality, QWindow *parent) override;
+    void hide() override;
+
+private:
+    QScopedPointer<QColorDialog> m_dialog;
+};
+
+QT_END_NAMESPACE
+
+#endif // QWIDGETPLATFORMCOLORDIALOG_P_H
diff --git a/src/imports/platform/widgets/qwidgetplatformdialog.cpp b/src/imports/platform/widgets/qwidgetplatformdialog.cpp
new file mode 100644
index 00000000..ebca7ea8
--- /dev/null
+++ b/src/imports/platform/widgets/qwidgetplatformdialog.cpp
@@ -0,0 +1,58 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt Labs Platform module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qwidgetplatformdialog_p.h"
+
+#include <QtGui/qwindow.h>
+#include <QtWidgets/qdialog.h>
+
+QT_BEGIN_NAMESPACE
+
+bool QWidgetPlatformDialog::show(QDialog *dialog, Qt::WindowFlags flags, Qt::WindowModality modality, QWindow *parent)
+{
+    dialog->setWindowFlags(flags);
+    dialog->setWindowModality(modality);
+
+    dialog->createWinId();
+    QWindow *handle = dialog->windowHandle();
+    Q_ASSERT(handle);
+    handle->setTransientParent(const_cast<QWindow *>(parent));
+
+    dialog->show();
+    return true;
+}
+
+QT_END_NAMESPACE
diff --git a/src/imports/platform/widgets/qwidgetplatformdialog_p.h b/src/imports/platform/widgets/qwidgetplatformdialog_p.h
new file mode 100644
index 00000000..efc99b85
--- /dev/null
+++ b/src/imports/platform/widgets/qwidgetplatformdialog_p.h
@@ -0,0 +1,66 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt Labs Platform module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QWIDGETPLATFORMDIALOG_P_H
+#define QWIDGETPLATFORMDIALOG_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtCore/qnamespace.h>
+
+QT_BEGIN_NAMESPACE
+
+class QDialog;
+class QWindow;
+
+class QWidgetPlatformDialog
+{
+public:
+    static bool show(QDialog *dialog, Qt::WindowFlags flags, Qt::WindowModality modality, QWindow *parent);
+};
+
+QT_END_NAMESPACE
+
+#endif // QWIDGETPLATFORMDIALOG_P_H
diff --git a/src/imports/platform/widgets/qwidgetplatformfontdialog.cpp b/src/imports/platform/widgets/qwidgetplatformfontdialog.cpp
new file mode 100644
index 00000000..af335b03
--- /dev/null
+++ b/src/imports/platform/widgets/qwidgetplatformfontdialog.cpp
@@ -0,0 +1,98 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt Labs Platform module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qwidgetplatformfontdialog_p.h"
+#include "qwidgetplatformdialog_p.h"
+#include "qwidgetplatform_p.h"
+
+#include <QtWidgets/qfontdialog.h>
+
+QT_BEGIN_NAMESPACE
+
+QWidgetPlatformFontDialog::QWidgetPlatformFontDialog(QObject *parent)
+{
+    setParent(parent);
+
+    static bool available = QWidgetPlatform::isAvailable("font dialog");
+    if (available) {
+        m_dialog.reset(new QFontDialog);
+        connect(m_dialog.data(), &QFontDialog::accepted, this, &QPlatformDialogHelper::accept);
+        connect(m_dialog.data(), &QFontDialog::rejected, this, &QPlatformDialogHelper::reject);
+        connect(m_dialog.data(), &QFontDialog::fontSelected, this, &QPlatformFontDialogHelper::fontSelected);
+        connect(m_dialog.data(), &QFontDialog::currentFontChanged, this, &QPlatformFontDialogHelper::currentFontChanged);
+    }
+}
+
+QWidgetPlatformFontDialog::~QWidgetPlatformFontDialog()
+{
+}
+
+QFont QWidgetPlatformFontDialog::currentFont() const
+{
+    return m_dialog ? m_dialog->currentFont() : QFont();
+}
+
+void QWidgetPlatformFontDialog::setCurrentFont(const QFont &font)
+{
+    if (m_dialog)
+        m_dialog->setCurrentFont(font);
+}
+
+void QWidgetPlatformFontDialog::exec()
+{
+    if (m_dialog)
+        m_dialog->exec();
+}
+
+bool QWidgetPlatformFontDialog::show(Qt::WindowFlags flags, Qt::WindowModality modality, QWindow *parent)
+{
+    if (!m_dialog)
+        return false;
+
+    QSharedPointer<QFontDialogOptions> options = QPlatformFontDialogHelper::options();
+    m_dialog->setWindowTitle(options->windowTitle());
+    m_dialog->setOptions(static_cast<QFontDialog::FontDialogOptions>(int(options->options())));
+
+    return QWidgetPlatformDialog::show(m_dialog.data(), flags, modality, parent);
+}
+
+void QWidgetPlatformFontDialog::hide()
+{
+    if (m_dialog)
+        m_dialog->hide();
+}
+
+QT_END_NAMESPACE
diff --git a/src/imports/platform/widgets/qwidgetplatformfontdialog_p.h b/src/imports/platform/widgets/qwidgetplatformfontdialog_p.h
new file mode 100644
index 00000000..97d5463d
--- /dev/null
+++ b/src/imports/platform/widgets/qwidgetplatformfontdialog_p.h
@@ -0,0 +1,78 @@
+/****************************************************************************
+**
+** Copyright (C) 2016 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt Labs Platform module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL3$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see http://www.qt.io/terms-conditions. For further
+** information use the contact form at http://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPLv3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or later as published by the Free
+** Software Foundation and appearing in the file LICENSE.GPL included in
+** the packaging of this file. Please review the following information to
+** ensure the GNU General Public License version 2.0 requirements will be
+** met: http://www.gnu.org/licenses/gpl-2.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#ifndef QWIDGETPLATFORMFONTDIALOG_P_H
+#define QWIDGETPLATFORMFONTDIALOG_P_H
+
+//
+//  W A R N I N G
+//  -------------
+//
+// This file is not part of the Qt API.  It exists purely as an
+// implementation detail.  This header file may change from version to
+// version without notice, or even be removed.
+//
+// We mean it.
+//
+
+#include <QtGui/qpa/qplatformdialoghelper.h>
+
+QT_BEGIN_NAMESPACE
+
+class QFontDialog;
+
+class QWidgetPlatformFontDialog : public QPlatformFontDialogHelper
+{
+    Q_OBJECT
+
+public:
+    explicit QWidgetPlatformFontDialog(QObject *parent = nullptr);
+    ~QWidgetPlatformFontDialog();
+
+    QFont currentFont() const override;
+    void setCurrentFont(const QFont &font) override;
+
+    void exec() override;
+    bool show(Qt::WindowFlags windowFlags, Qt::WindowModality windowModality, QWindow *parent) override;
+    void hide() override;
+
+private:
+    QScopedPointer<QFontDialog> m_dialog;
+};
+
+QT_END_NAMESPACE
+
+#endif // QWIDGETPLATFORMFONTDIALOG_P_H
diff --git a/src/imports/platform/widgets/widgets.pri b/src/imports/platform/widgets/widgets.pri
index a816d487..a9e5d42b 100644
--- a/src/imports/platform/widgets/widgets.pri
+++ b/src/imports/platform/widgets/widgets.pri
@@ -1,12 +1,19 @@
 QT += widgets
+DEPENDPATH += $$PWD
 
 HEADERS += \
     $$PWD/qwidgetplatform_p.h \
+    $$PWD/qwidgetplatformcolordialog_p.h \
+    $$PWD/qwidgetplatformdialog_p.h \
+    $$PWD/qwidgetplatformfontdialog_p.h \
     $$PWD/qwidgetplatformmenu_p.h \
     $$PWD/qwidgetplatformmenuitem_p.h \
     $$PWD/qwidgetplatformsystemtrayicon_p.h
 
 SOURCES += \
+    $$PWD/qwidgetplatformcolordialog.cpp \
+    $$PWD/qwidgetplatformdialog.cpp \
+    $$PWD/qwidgetplatformfontdialog.cpp \
     $$PWD/qwidgetplatformmenu.cpp \
     $$PWD/qwidgetplatformmenuitem.cpp \
     $$PWD/qwidgetplatformsystemtrayicon.cpp