1 files changed, 199 insertions, 0 deletions
diff --git a/src/quick/items/qquickpalettecolorprovider.cpp b/src/quick/items/qquickpalettecolorprovider.cpp
new file mode 100644
index 0000000000..f01fa22bdd
--- /dev/null
+++ b/src/quick/items/qquickpalettecolorprovider.cpp
@@ -0,0 +1,199 @@
+// Copyright (C) 2020 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+#include "qquickpalettecolorprovider_p.h"
+
+#include <QtQuick/private/qquickabstractpaletteprovider_p.h>
+#include <QtGui/private/qpalette_p.h>
+
+QT_BEGIN_NAMESPACE
+
+static bool notEq(const QPalette &p1, const QPalette &p2)
+{
+    return p1.resolveMask() != p2.resolveMask() || p1 != p2;
+}
+
+static QPalette::ColorGroup adjustCg(QPalette::ColorGroup group)
+{
+    return group == QPalette::All ? QPalette::Active : group;
+}
+
+class DefaultPalettesProvider : public QQuickAbstractPaletteProvider
+{
+public:
+    QPalette defaultPalette() const override { static QPalette p; return p; }
+};
+
+static std::default_delete<const QQuickAbstractPaletteProvider> defaultDeleter() { return {}; }
+
+QQuickPaletteColorProvider::QQuickPaletteColorProvider()
+    : m_paletteProvider(ProviderPtr(new DefaultPalettesProvider, defaultDeleter()))
+{
+}
+
+const QColor &QQuickPaletteColorProvider::color(QPalette::ColorGroup group, QPalette::ColorRole role) const
+{
+    return m_resolvedPalette.color(adjustCg(group), role);
+}
+
+bool QQuickPaletteColorProvider::setColor(QPalette::ColorGroup g, QPalette::ColorRole r, QColor c)
+{
+    ensureRequestedPalette();
+    m_requestedPalette->setColor(g, r, c);
+
+    return updateInheritedPalette();
+}
+
+bool QQuickPaletteColorProvider::resetColor(QPalette::ColorGroup group, QPalette::ColorRole role)
+{
+    if (!m_requestedPalette.isAllocated())
+        return false;
+
+    QPalette::ResolveMask unsetResolveMask = 0;
+
+    if (group == QPalette::Current)
+        group = m_requestedPalette->currentColorGroup();
+
+    if (group == QPalette::All) {
+        for (int g = QPalette::Active; g < QPalette::NColorGroups; ++g)
+            unsetResolveMask |= (QPalette::ResolveMask(1) << QPalettePrivate::bitPosition(QPalette::ColorGroup(g), role));
+    } else {
+        unsetResolveMask = (QPalette::ResolveMask(1) << QPalettePrivate::bitPosition(group, role));
+    }
+
+    m_requestedPalette->setResolveMask(m_requestedPalette->resolveMask() & ~unsetResolveMask);
+
+    return updateInheritedPalette();
+}
+
+bool QQuickPaletteColorProvider::resetColor(QPalette::ColorGroup group)
+{
+    if (!m_requestedPalette.isAllocated())
+        return false;
+
+    QPalette::ResolveMask unsetResolveMask = 0;
+
+    auto getResolveMask = [] (QPalette::ColorGroup group) {
+        QPalette::ResolveMask mask = 0;
+        for (int roleIndex = QPalette::WindowText; roleIndex < QPalette::NColorRoles; ++roleIndex) {
+            const auto cr = QPalette::ColorRole(roleIndex);
+            mask |= (QPalette::ResolveMask(1) << QPalettePrivate::bitPosition(group, cr));
+        }
+        return mask;
+    };
+
+    if (group == QPalette::Current)
+        group = m_requestedPalette->currentColorGroup();
+
+    if (group == QPalette::All) {
+        for (int g = QPalette::Active; g < QPalette::NColorGroups; ++g)
+            unsetResolveMask |= getResolveMask(QPalette::ColorGroup(g));
+    } else {
+        unsetResolveMask = getResolveMask(group);
+    }
+
+    m_requestedPalette->setResolveMask(m_requestedPalette->resolveMask() & ~unsetResolveMask);
+
+    return updateInheritedPalette();
+}
+
+bool QQuickPaletteColorProvider::fromQPalette(QPalette p)
+{
+    m_requestedPalette.value() = std::move(p);
+    return updateInheritedPalette();
+}
+
+QPalette QQuickPaletteColorProvider::palette() const
+{
+    return m_resolvedPalette;
+}
+
+const QQuickAbstractPaletteProvider *QQuickPaletteColorProvider::paletteProvider() const
+{
+    Q_ASSERT(m_paletteProvider);
+    return m_paletteProvider.get();
+}
+
+void QQuickPaletteColorProvider::setPaletteProvider(const QQuickAbstractPaletteProvider *paletteProvider)
+{
+    static const auto emptyDeleter = [](auto &&){};
+    m_paletteProvider = ProviderPtr(paletteProvider, emptyDeleter);
+}
+
+bool QQuickPaletteColorProvider::copyColorGroup(QPalette::ColorGroup cg,
+                                                const QQuickPaletteColorProvider &p)
+{
+    ensureRequestedPalette();
+
+    auto srcPalette = p.palette();
+    for (int roleIndex = QPalette::WindowText; roleIndex < QPalette::NColorRoles; ++roleIndex) {
+        const auto cr = QPalette::ColorRole(roleIndex);
+        if (srcPalette.isBrushSet(cg, cr)) {
+            m_requestedPalette->setBrush(cg, cr, srcPalette.brush(cg, cr));
+        }
+    }
+
+    return updateInheritedPalette();
+}
+
+bool QQuickPaletteColorProvider::reset()
+{
+    return fromQPalette(QPalette());
+}
+
+/*! \internal
+    Merge the given \a palette with the existing requested palette, remember
+    that it is the inherited palette (in case updateInheritedPalette() is
+    called later), and update the stored palette (to be returned from
+    \l palette()) if the result is different. Returns whether the stored
+    palette got changed.
+*/
+bool QQuickPaletteColorProvider::inheritPalette(const QPalette &palette)
+{
+    m_lastInheritedPalette.value() = palette;
+    return doInheritPalette(palette);
+}
+
+/*! \internal
+    Merge the given \a palette with the existing requested palette, and update
+    the stored palette (to be returned from \l palette()) if the result is
+    different. Returns whether the stored palette got changed.
+*/
+bool QQuickPaletteColorProvider::doInheritPalette(const QPalette &palette)
+{
+    auto inheritedMask = m_requestedPalette.isAllocated() ? m_requestedPalette->resolveMask() | palette.resolveMask()
+                                                          : palette.resolveMask();
+    // If a palette was set on this item, it should always win over the palette to be inherited from.
+    QPalette parentPalette = m_requestedPalette.isAllocated() ? m_requestedPalette->resolve(palette) : palette;
+    parentPalette.setResolveMask(inheritedMask);
+
+    auto tmpResolvedPalette = parentPalette.resolve(paletteProvider()->defaultPalette());
+    tmpResolvedPalette.setResolveMask(tmpResolvedPalette.resolveMask() | inheritedMask);
+
+    bool changed = notEq(tmpResolvedPalette, m_resolvedPalette);
+    if (changed)
+        std::swap(tmpResolvedPalette, m_resolvedPalette);
+
+    return changed;
+}
+
+/*! \internal
+    Update the stored palette (to be returned from \l palette()) from the
+    parent palette. Returns whether the stored palette got changed.
+*/
+bool QQuickPaletteColorProvider::updateInheritedPalette()
+{
+    // Use last inherited palette as parentPalette's fallbackPalette: it's useful when parentPalette doesn't exist.
+    const QPalette &p = m_lastInheritedPalette.isAllocated() ? m_lastInheritedPalette.value()
+                                                             : paletteProvider()->defaultPalette();
+    return doInheritPalette(paletteProvider()->parentPalette(p));
+}
+
+void QQuickPaletteColorProvider::ensureRequestedPalette()
+{
+    if (m_requestedPalette.isAllocated())
+        return;
+
+    m_requestedPalette.value() = QPalette();
+}
+
+QT_END_NAMESPACE