Move Default style out into its own plugin

In upcoming patches, we start registering C++ types declaratively.
A condition of doing so requires that each .pro corresponds to one
QML module. This conflicts with the QtQuick.Controls import, which
currently does quite a lot:

- Registers (and selects) QML files for the style that was set
- Registers private C++ utility types (such as IconLabel) that are
  useful for all styles under the QtQuick.Controls.impl import
- Registers private C++ types that are only useful for the Default
  style (such as BusyIndicatorImpl).

The reason it does so much can probably be explained by the
intended usage of Qt Quick Controls 2; when you do

    import QtQuick.Controls 2.0

you get access to the QML types (e.g. Button) that the style
you're using provides. So if you're using the Material style,
you'll get a Material style button. API-wise, the button is
identical to any other button, because the types in
QtQuick.Templates are what we advertise as the public API.

If we didn't have this functionality, users would need to
import specific style imports to use controls, and the
convenience of being able to simply start the application
with a different style by e.g. passing an application argument
would be lost.

To support declarative registration of types while also supporting
the existing use cases, we split out the Default-style-specific
stuff into a QtQuick.Controls.Default import.

Task-number: QTBUG-82922
Change-Id: Ib4f1620cae78d7acdc13d9ac0752a020bc22f3ea
Reviewed-by: Ulf Hermann <ulf.hermann@qt.io>

1 files changed, 280 insertions, 0 deletions

diff --git a/src/imports/controls/default/qquickdefaultprogressbar.cpp b/src/imports/controls/default/qquickdefaultprogressbar.cpp
new file mode 100644
index 00000000..f44065e4
--- /dev/null
+++ b/src/imports/controls/default/qquickdefaultprogressbar.cpp
@@ -0,0 +1,280 @@
+/****************************************************************************
+**
+** 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 "qquickdefaultprogressbar_p.h"
+
+#include <QtCore/qeasingcurve.h>
+#include <QtQuick/private/qquickitem_p.h>
+#include <QtQuick/private/qsgadaptationlayer_p.h>
+#include <QtQuickControls2/private/qquickanimatednode_p.h>
+
+QT_BEGIN_NAMESPACE
+
+static const int Blocks = 4;
+static const int BlockWidth = 16;
+static const int BlockRestingSpacing = 4;
+static const int BlockMovingSpacing = 48;
+static const int BlockSpan = Blocks * (BlockWidth + BlockRestingSpacing) - BlockRestingSpacing;
+static const int TotalDuration = 4000;
+static const int SecondPhaseStart = TotalDuration * 0.4;
+static const int ThirdPhaseStart = TotalDuration * 0.6;
+
+static inline qreal blockStartX(int blockIndex)
+{
+    return ((blockIndex + 1) * -BlockWidth) - (blockIndex * BlockMovingSpacing);
+}
+
+static inline qreal blockRestX(int blockIndex, qreal availableWidth)
+{
+    const qreal spanRightEdgePos = availableWidth / 2 + BlockSpan / 2.0;
+    return spanRightEdgePos - (blockIndex + 1) * BlockWidth - (blockIndex * BlockRestingSpacing);
+}
+
+static inline qreal blockEndX(int blockIndex, qreal availableWidth)
+{
+    return availableWidth - blockStartX(Blocks - 1 - blockIndex) - BlockWidth;
+}
+
+class QQuickDefaultProgressBarNode : public QQuickAnimatedNode
+{
+public:
+    QQuickDefaultProgressBarNode(QQuickDefaultProgressBar *item);
+
+    void updateCurrentTime(int time) override;
+    void sync(QQuickItem *item) override;
+
+private:
+    bool m_indeterminate = false;
+    qreal m_pixelsPerSecond = 0;
+};
+
+QQuickDefaultProgressBarNode::QQuickDefaultProgressBarNode(QQuickDefaultProgressBar *item)
+    : QQuickAnimatedNode(item),
+      m_pixelsPerSecond(item->width())
+{
+    setLoopCount(Infinite);
+    setDuration(TotalDuration);
+}
+
+void QQuickDefaultProgressBarNode::updateCurrentTime(int time)
+{
+    QSGTransformNode *transformNode = static_cast<QSGTransformNode*>(firstChild());
+    for (int i = 0; i < Blocks; ++i) {
+        Q_ASSERT(transformNode->type() == QSGNode::TransformNodeType);
+
+        QMatrix4x4 m;
+        const qreal restX = blockRestX(i, m_pixelsPerSecond);
+        const qreal timeInSeconds = time / 1000.0;
+
+        if (time < SecondPhaseStart) {
+            // Move into the resting position for the first phase.
+            QEasingCurve easingCurve(QEasingCurve::InQuad);
+            const qreal easedCompletion = easingCurve.valueForProgress(time / qreal(SecondPhaseStart));
+            const qreal distance = m_pixelsPerSecond * (easedCompletion * (SecondPhaseStart / 1000.0));
+            const qreal position = blockStartX(i) + distance;
+            const qreal destination = restX;
+            m.translate(qMin(position, destination), 0);
+        } else if (time < ThirdPhaseStart) {
+            // Stay in the same position for the second phase.
+            m.translate(restX, 0);
+        } else {
+            // Move out of view for the third phase.
+            const int thirdPhaseSubKickoff = (BlockMovingSpacing / m_pixelsPerSecond) * 1000;
+            const int subphase = (time - ThirdPhaseStart) / thirdPhaseSubKickoff;
+            // If we're not at this subphase yet, don't try to animate movement,
+            // because it will be incorrect.
+            if (subphase < i)
+                return;
+
+            const qreal timeSinceSecondPhase = timeInSeconds - (ThirdPhaseStart / 1000.0);
+            // We only want to start keeping track of time once our subphase has started,
+            // otherwise we move too much because we account for time that has already elapsed.
+            // For example, if we were 60 milliseconds into the third subphase:
+            //
+            //      0 ..... 1 ..... 2 ...
+            //         100     100     60
+            //
+            // i == 0, timeSinceOurKickoff == 260
+            // i == 1, timeSinceOurKickoff == 160
+            // i == 2, timeSinceOurKickoff ==  60
+            const qreal timeSinceOurKickoff = timeSinceSecondPhase - (thirdPhaseSubKickoff / 1000.0 * i);
+            const qreal position = restX + (m_pixelsPerSecond * (timeSinceOurKickoff));
+            const qreal destination = blockEndX(i, m_pixelsPerSecond);
+            m.translate(qMin(position, destination), 0);
+        }
+
+        transformNode->setMatrix(m);
+
+        transformNode = static_cast<QSGTransformNode*>(transformNode->nextSibling());
+    }
+}
+
+void QQuickDefaultProgressBarNode::sync(QQuickItem *item)
+{
+    QQuickDefaultProgressBar *bar = static_cast<QQuickDefaultProgressBar *>(item);
+    if (m_indeterminate != bar->isIndeterminate()) {
+        m_indeterminate = bar->isIndeterminate();
+        if (m_indeterminate)
+            start();
+        else
+            stop();
+    }
+    m_pixelsPerSecond = item->width();
+
+    QQuickItemPrivate *d = QQuickItemPrivate::get(item);
+
+    QMatrix4x4 m;
+    m.translate(0, (item->height() - item->implicitHeight()) / 2);
+    setMatrix(m);
+
+    if (m_indeterminate) {
+        if (childCount() != Blocks) {
+            // This was previously a regular progress bar; remove the old nodes.
+            removeAllChildNodes();
+        }
+
+        QSGTransformNode *transformNode = static_cast<QSGTransformNode*>(firstChild());
+        for (int i = 0; i < Blocks; ++i) {
+            if (!transformNode) {
+                transformNode = new QSGTransformNode;
+                appendChildNode(transformNode);
+            }
+
+            QSGInternalRectangleNode *rectNode = static_cast<QSGInternalRectangleNode*>(transformNode->firstChild());
+            if (!rectNode) {
+                rectNode = d->sceneGraphContext()->createInternalRectangleNode();
+                rectNode->setColor(bar->color());
+                transformNode->appendChildNode(rectNode);
+            }
+
+            QMatrix4x4 m;
+            m.translate(blockStartX(i), 0);
+            transformNode->setMatrix(m);
+
+            rectNode->setRect(QRectF(QPointF(0, 0), QSizeF(BlockWidth, item->implicitHeight())));
+            rectNode->update();
+
+            transformNode = static_cast<QSGTransformNode *>(transformNode->nextSibling());
+        }
+    } else {
+        if (childCount() > 1) {
+            // This was previously an indeterminate progress bar; remove the old nodes.
+            removeAllChildNodes();
+        }
+
+        QSGInternalRectangleNode *rectNode = static_cast<QSGInternalRectangleNode *>(firstChild());
+        if (!rectNode) {
+            rectNode = d->sceneGraphContext()->createInternalRectangleNode();
+            rectNode->setColor(bar->color());
+            appendChildNode(rectNode);
+        }
+
+        rectNode->setRect(QRectF(QPointF(0, 0), QSizeF(bar->progress() * item->width(), item->implicitHeight())));
+        rectNode->update();
+    }
+}
+
+QQuickDefaultProgressBar::QQuickDefaultProgressBar(QQuickItem *parent) :
+    QQuickItem(parent)
+{
+    setFlag(ItemHasContents);
+}
+
+qreal QQuickDefaultProgressBar::progress() const
+{
+    return m_progress;
+}
+
+void QQuickDefaultProgressBar::setProgress(qreal progress)
+{
+    if (progress == m_progress)
+        return;
+
+    m_progress = progress;
+    update();
+}
+
+bool QQuickDefaultProgressBar::isIndeterminate() const
+{
+    return m_indeterminate;
+}
+
+void QQuickDefaultProgressBar::setIndeterminate(bool indeterminate)
+{
+    if (indeterminate == m_indeterminate)
+        return;
+
+    m_indeterminate = indeterminate;
+    setClip(m_indeterminate);
+    update();
+}
+
+QColor QQuickDefaultProgressBar::color() const
+{
+    return m_color;
+}
+
+void QQuickDefaultProgressBar::setColor(const QColor &color)
+{
+    if (color == m_color)
+        return;
+
+    m_color = color;
+    update();
+}
+
+void QQuickDefaultProgressBar::itemChange(QQuickItem::ItemChange change, const QQuickItem::ItemChangeData &data)
+{
+    QQuickItem::itemChange(change, data);
+    if (change == ItemVisibleHasChanged)
+        update();
+}
+
+QSGNode *QQuickDefaultProgressBar::updatePaintNode(QSGNode *oldNode, QQuickItem::UpdatePaintNodeData *)
+{
+    QQuickDefaultProgressBarNode *node = static_cast<QQuickDefaultProgressBarNode *>(oldNode);
+    if (isVisible() && width() > 0 && height() > 0) {
+        if (!node)
+            node = new QQuickDefaultProgressBarNode(this);
+        node->sync(this);
+    } else {
+        delete node;
+        node = nullptr;
+    }
+    return node;
+}
+
+QT_END_NAMESPACE