Adding QPlatformMessageDialogHelper and QMessageDialogOptions

We plan to add support for native message/alert dialogs on Android
and iOS because it's otherwise impossible to have a true popup window.
Then we might as well have native message/alert dialogs on other
platforms too.  It will become an alternative implementation behind
QMessageBox and perhaps QErrorMessage.

Task-number: QTBUG-30883
Task-number: QTBUG-29462
Change-Id: I73dcfc6438e696189b6d37091874c7ad69b4ec68
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@digia.com>
Reviewed-by: Richard Moe Gustavsen <richard.gustavsen@digia.com>

src/gui/kernel/qplatformdialoghelper.cpp

@@ -596,4 +596,121 @@ QStringList QPlatformFileDialogHelper::cleanFilterList(const QString &filter)
     return f.split(QLatin1Char(' '), QString::SkipEmptyParts);
 }
 
+// Message dialog
+
+class QMessageDialogOptionsPrivate : public QSharedData
+{
+public:
+    QMessageDialogOptionsPrivate() :
+        icon(QMessageDialogOptions::NoIcon),
+        buttons(QMessageDialogOptions::Ok)
+    {}
+
+    QString windowTitle;
+    QMessageDialogOptions::Icon icon;
+    QString text;
+    QString informativeText;
+    QString detailedText;
+    QMessageDialogOptions::StandardButtons buttons;
+};
+
+QMessageDialogOptions::QMessageDialogOptions() : d(new QMessageDialogOptionsPrivate)
+{
+}
+
+QMessageDialogOptions::QMessageDialogOptions(const QMessageDialogOptions &rhs) : d(rhs.d)
+{
+}
+
+QMessageDialogOptions &QMessageDialogOptions::operator=(const QMessageDialogOptions &rhs)
+{
+    if (this != &rhs)
+        d = rhs.d;
+    return *this;
+}
+
+QMessageDialogOptions::~QMessageDialogOptions()
+{
+}
+
+QString QMessageDialogOptions::windowTitle() const
+{
+    return d->windowTitle;
+}
+
+void QMessageDialogOptions::setWindowTitle(const QString &title)
+{
+    d->windowTitle = title;
+}
+
+QMessageDialogOptions::Icon QMessageDialogOptions::icon() const
+{
+    return d->icon;
+}
+
+void QMessageDialogOptions::setIcon(Icon icon)
+{
+    d->icon = icon;
+}
+
+QString QMessageDialogOptions::text() const
+{
+    return d->text;
+}
+
+void QMessageDialogOptions::setText(const QString &text)
+{
+    d->text = text;
+}
+
+QString QMessageDialogOptions::informativeText() const
+{
+    return d->informativeText;
+}
+
+void QMessageDialogOptions::setInformativeText(const QString &informativeText)
+{
+    d->informativeText = informativeText;
+}
+
+QString QMessageDialogOptions::detailedText() const
+{
+    return d->detailedText;
+}
+
+void QMessageDialogOptions::setDetailedText(const QString &detailedText)
+{
+    d->detailedText = detailedText;
+}
+
+void QMessageDialogOptions::setStandardButtons(StandardButtons buttons)
+{
+    d->buttons = buttons;
+}
+
+QMessageDialogOptions::StandardButtons QMessageDialogOptions::standardButtons() const
+{
+    return d->buttons;
+}
+
+
+/*!
+    \class QPlatformMessageDialogHelper
+    \since 5.0
+    \internal
+    \ingroup qpa
+
+    \brief The QPlatformMessageDialogHelper class allows for platform-specific customization of Message dialogs.
+
+*/
+const QSharedPointer<QMessageDialogOptions> &QPlatformMessageDialogHelper::options() const
+{
+    return m_options;
+}
+
+void QPlatformMessageDialogHelper::setOptions(const QSharedPointer<QMessageDialogOptions> &options)
+{
+    m_options = options;
+}
+
 QT_END_NAMESPACE

src/gui/kernel/qplatformdialoghelper.h

@@ -72,6 +72,7 @@ class QUrl;
 class QColorDialogOptionsPrivate;
 class QFontDialogOptionsPrivate;
 class QFileDialogOptionsPrivate;
+class QMessageDialogOptionsPrivate;
 
 class Q_GUI_EXPORT QPlatformDialogHelper : public QObject
 {
@@ -325,6 +326,86 @@ private:
     QSharedPointer<QFileDialogOptions> m_options;
 };
 
+class Q_GUI_EXPORT QMessageDialogOptions
+{
+public:
+    // Keep in sync with QMessageBox::Icon
+    enum Icon { NoIcon, Information, Warning, Critical, Question };
+
+    enum StandardButton {
+        // keep this in sync with QDialogButtonBox::StandardButton and QMessageBox::StandardButton
+        NoButton           = 0x00000000,
+        Ok                 = 0x00000400,
+        Save               = 0x00000800,
+        SaveAll            = 0x00001000,
+        Open               = 0x00002000,
+        Yes                = 0x00004000,
+        YesToAll           = 0x00008000,
+        No                 = 0x00010000,
+        NoToAll            = 0x00020000,
+        Abort              = 0x00040000,
+        Retry              = 0x00080000,
+        Ignore             = 0x00100000,
+        Close              = 0x00200000,
+        Cancel             = 0x00400000,
+        Discard            = 0x00800000,
+        Help               = 0x01000000,
+        Apply              = 0x02000000,
+        Reset              = 0x04000000,
+        RestoreDefaults    = 0x08000000,
+
+
+        FirstButton        = Ok,                // internal
+        LastButton         = RestoreDefaults    // internal
+    };
+
+    Q_DECLARE_FLAGS(StandardButtons, StandardButton)
+
+    QMessageDialogOptions();
+    QMessageDialogOptions(const QMessageDialogOptions &rhs);
+    QMessageDialogOptions &operator=(const QMessageDialogOptions &rhs);
+    ~QMessageDialogOptions();
+
+    void swap(QMessageDialogOptions &other) { qSwap(d, other.d); }
+
+    QString windowTitle() const;
+    void setWindowTitle(const QString &);
+
+    void setIcon(Icon icon);
+    Icon icon() const;
+
+    void setText(const QString &text);
+    QString text() const;
+
+    void setInformativeText(const QString &text);
+    QString informativeText() const;
+
+    void setDetailedText(const QString &text);
+    QString detailedText() const;
+
+    void setStandardButtons(StandardButtons buttons);
+    StandardButtons standardButtons() const;
+
+private:
+    QSharedDataPointer<QMessageDialogOptionsPrivate> d;
+};
+
+Q_DECLARE_SHARED(QMessageDialogOptions)
+
+class Q_GUI_EXPORT QPlatformMessageDialogHelper : public QPlatformDialogHelper
+{
+    Q_OBJECT
+public:
+    const QSharedPointer<QMessageDialogOptions> &options() const;
+    void setOptions(const QSharedPointer<QMessageDialogOptions> &options);
+
+Q_SIGNALS:
+    void clicked(QMessageDialogOptions::StandardButton button);
+
+private:
+    QSharedPointer<QMessageDialogOptions> m_options;
+};
+
 QT_END_NAMESPACE
 
 #endif // QPLATFORMDIALOGHELPER_H

src/gui/kernel/qplatformtheme.h

@@ -112,7 +112,8 @@ public:
     enum DialogType {
         FileDialog,
         ColorDialog,
-        FontDialog
+        FontDialog,
+        MessageDialog
     };
 
     enum Palette {

src/widgets/dialogs/qmessagebox.h

@@ -95,7 +95,7 @@ public:
     };
 
     enum StandardButton {
-        // keep this in sync with QDialogButtonBox::StandardButton
+        // keep this in sync with QDialogButtonBox::StandardButton and QMessageDialogOptions::StandardButton
         NoButton           = 0x00000000,
         Ok                 = 0x00000400,
         Save               = 0x00000800,