Add Imagine style

The Imagine style is based on image assets. The style comes with a
default set of images, but the images can be easily changed by
providing a directory with images using a predefined naming convention.

[ChangeLog][Controls] Added the Imagine style, which is based on
image assets that can be provided using a predefined naming convention.

Task-number: QTPM-517
Change-Id: I550d7dac9a9686d60bec15655ac92dea9f36149c
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

1 files changed, 147 insertions, 0 deletions

diff --git a/src/imports/controls/imagine/qquickimaginestyle.cpp b/src/imports/controls/imagine/qquickimaginestyle.cpp
new file mode 100644
index 00000000..e103421e
--- /dev/null
+++ b/src/imports/controls/imagine/qquickimaginestyle.cpp
@@ -0,0 +1,147 @@
+/****************************************************************************
+**
+** Copyright (C) 2017 The Qt Company Ltd.
+** Contact: http://www.qt.io/licensing/
+**
+** This file is part of the Qt Quick Controls 2 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 "qquickimaginestyle_p.h"
+
+#include <QtCore/qsettings.h>
+#include <QtQuickControls2/private/qquickstyle_p.h>
+
+QT_BEGIN_NAMESPACE
+
+Q_GLOBAL_STATIC_WITH_ARGS(QString, GlobalPath, (QLatin1String("qrc:/qt-project.org/imports/QtQuick/Controls.2/Imagine/images/")))
+
+static const QString ensureSlash(const QString &path)
+{
+    const QChar slash = QLatin1Char('/');
+    return path.endsWith(slash) ? path : path + slash;
+}
+
+QQuickImagineStyle::QQuickImagineStyle(QObject *parent)
+    : QQuickAttachedObject(parent),
+      m_explicitPath(false),
+      m_path(*GlobalPath())
+{
+    init();
+}
+
+QQuickImagineStyle *QQuickImagineStyle::qmlAttachedProperties(QObject *object)
+{
+    return new QQuickImagineStyle(object);
+}
+
+QString QQuickImagineStyle::path() const
+{
+    return m_path; // ### TODO: url?
+}
+
+void QQuickImagineStyle::setPath(const QString &path)
+{
+    QString p = ensureSlash(path);
+    m_explicitPath = true;
+    if (m_path == p)
+        return;
+
+    m_path = p;
+    propagatePath();
+
+    emit pathChanged();
+}
+
+void QQuickImagineStyle::inheritPath(const QString &path)
+{
+    if (m_explicitPath || m_path == path)
+        return;
+
+    m_path = path;
+    propagatePath();
+    emit pathChanged();
+}
+
+void QQuickImagineStyle::propagatePath()
+{
+    const auto styles = attachedChildren();
+    for (QQuickAttachedObject *child : styles) {
+        QQuickImagineStyle *imagine = qobject_cast<QQuickImagineStyle *>(child);
+        if (imagine)
+            imagine->inheritPath(m_path);
+    }
+}
+
+void QQuickImagineStyle::resetPath()
+{
+    if (!m_explicitPath)
+        return;
+
+    m_explicitPath = false;
+    QQuickImagineStyle *imagine = qobject_cast<QQuickImagineStyle *>(attachedParent());
+    inheritPath(imagine ? imagine->path() : *GlobalPath());
+}
+
+void QQuickImagineStyle::attachedParentChange(QQuickAttachedObject *newParent, QQuickAttachedObject *oldParent)
+{
+    Q_UNUSED(oldParent);
+    QQuickImagineStyle *imagine = qobject_cast<QQuickImagineStyle *>(newParent);
+    if (imagine)
+        inheritPath(imagine->path());
+}
+
+static QByteArray resolveSetting(const QByteArray &env, const QSharedPointer<QSettings> &settings, const QString &name)
+{
+    QByteArray value = qgetenv(env);
+#if QT_CONFIG(settings)
+    if (value.isNull() && !settings.isNull())
+        value = settings->value(name).toByteArray();
+#endif
+    return value;
+}
+
+void QQuickImagineStyle::init()
+{
+    static bool globalsInitialized = false;
+    if (!globalsInitialized) {
+        QSharedPointer<QSettings> settings = QQuickStylePrivate::settings(QStringLiteral("Imagine"));
+
+        QString path = QString::fromUtf8(resolveSetting("QT_QUICK_CONTROLS_IMAGINE_PATH", settings, QStringLiteral("Path")));
+        if (!path.isEmpty())
+            *GlobalPath() = m_path = ensureSlash(path);
+
+        globalsInitialized = true;
+    }
+
+    QQuickAttachedObject::init(); // TODO: lazy init?
+}
+
+QT_END_NAMESPACE