/*
 * Copyright (C) 2022 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include <WebCore/ScrollView.h>
#include <wtf/TZoneMalloc.h>

namespace WebCore {

class Frame;
class RenderElement;
enum class FrameOwnerElementAppearance : uint8_t;
enum class RenderAsTextFlag : uint16_t;

class FrameView : public ScrollView {
    WTF_MAKE_TZONE_ALLOCATED(FrameView);
    WTF_OVERRIDE_DELETE_FOR_CHECKED_PTR(FrameView);
public:
    enum class Type : bool { Local, Remote };
    virtual Type viewType() const = 0;
    virtual void writeRenderTreeAsText(TextStream&, OptionSet<RenderAsTextFlag>) = 0;
    virtual Frame& frame() const = 0;

    WEBCORE_EXPORT int headerHeight() const final;
    WEBCORE_EXPORT int footerHeight() const final;

    WEBCORE_EXPORT FloatBoxExtent obscuredContentInsets(InsetType = InsetType::WebCoreInset) const final;
    CornerRadii scrollbarAvoidanceCornerRadii() const override;

    float visibleContentScaleFactor() const final;

    HostWindow* hostWindow() const final;
    WEBCORE_EXPORT void invalidateRect(const IntRect&) final;
    bool isActive() const final;
    bool forceUpdateScrollbarsOnMainThreadForPerformanceTesting() const final;
    IntRect scrollableAreaBoundingBox(bool* = nullptr) const final;

    void scrollbarStyleChanged(ScrollbarStyle, bool forceUpdate) override;

    // Coordinate systems:
    //
    // "View"
    //     Top left is top left of the FrameView/ScrollView/Widget. Size is Widget::boundsRect().size().
    //
    // "TotalContents"
    //    Relative to ScrollView's scrolled contents, including headers and footers. Size is totalContentsSize().
    //
    // "Contents"
    //    Relative to ScrollView's scrolled contents, excluding headers and footers, so top left is top left of the scroll view's
    //    document, and size is contentsSize().
    //
    // "Absolute"
    //    Relative to the document's scroll origin (non-zero for RTL documents), but affected by page zoom and page scale. Mostly used
    //    in rendering code.
    //
    // "Document"
    //    Relative to the document's scroll origin, but not affected by page zoom or page scale. Size is equivalent to CSS pixel dimensions.
    //    FIXME: some uses are affected by page zoom (e.g. layout and visual viewports).
    //
    // "Client"
    //    Relative to the visible part of the document (or, more strictly, the layout viewport rect), and with the same scaling
    //    as Document coordinates, i.e. matching CSS pixels. Affected by scroll origin.
    //
    // "LayoutViewport"
    //    Similar to client coordinates, but affected by page zoom (but not page scale).
    //

    // Methods to convert points and rects between the coordinate space of the renderer, and this view.
    WEBCORE_EXPORT IntPoint convertFromRendererToContainingView(const RenderElement*, IntPoint) const;
    WEBCORE_EXPORT FloatPoint convertFromRendererToContainingView(const RenderElement*, FloatPoint) const;
    WEBCORE_EXPORT IntRect convertFromRendererToContainingView(const RenderElement*, const IntRect&) const;
    WEBCORE_EXPORT FloatRect convertFromRendererToContainingView(const RenderElement*, const FloatRect&) const;

    WEBCORE_EXPORT IntPoint convertFromContainingViewToRenderer(const RenderElement*, IntPoint) const;
    WEBCORE_EXPORT FloatPoint convertFromContainingViewToRenderer(const RenderElement*, FloatPoint) const;
    WEBCORE_EXPORT DoublePoint convertFromContainingViewToRenderer(const RenderElement*, DoublePoint) const;
    WEBCORE_EXPORT IntRect convertFromContainingViewToRenderer(const RenderElement*, const IntRect&) const;
    WEBCORE_EXPORT FloatRect convertFromContainingViewToRenderer(const RenderElement*, const FloatRect&) const;

    WEBCORE_EXPORT FloatPoint absoluteToLayoutViewportPoint(FloatPoint) const;
    FloatPoint layoutViewportToAbsolutePoint(FloatPoint) const;

    WEBCORE_EXPORT FloatRect absoluteToLayoutViewportRect(FloatRect) const;
    FloatRect layoutViewportToAbsoluteRect(FloatRect) const;

    // Override ScrollView methods to do point conversion via renderers, in order to take transforms into account.
    IntPoint convertToContainingView(IntPoint) const final;
    FloatPoint convertToContainingView(FloatPoint) const final;
    IntRect convertToContainingView(const IntRect&) const final;
    FloatRect convertToContainingView(const FloatRect&) const final;

    IntPoint convertFromContainingView(IntPoint) const final;
    FloatPoint convertFromContainingView(FloatPoint) const final;
    DoublePoint convertFromContainingView(DoublePoint) const final;
    IntRect convertFromContainingView(const IntRect&) const final;
    FloatRect convertFromContainingView(const FloatRect&) const final;

    WEBCORE_EXPORT virtual LayoutRect layoutViewportRect() const = 0;

    // Computes the visible area of a child frame in this frame as a rectangle.
    // std::nullopt is returned if the child frame is entirely invisible, or
    // the visible area is not computable. The given child frame must be a
    // direct child of this frame.
    virtual std::optional<LayoutRect> visibleRectOfChild(const Frame&) const = 0;

    // Returns the appearance info of the child frame's owner element (which is
    // in this frame). Note that this is _different_ from the child frame's
    // document's appearance, and they can be different (e.g the owner element
    // uses dark appearance, but the child frame's document is light).
    virtual OptionSet<FrameOwnerElementAppearance> appearanceOfOwnerElementOfChildFrame(const Frame&) const = 0;

    // Returns the offset of the content box of the child's frame owner content box
    // from its border box. This can be non-zero due to padding or border.
    virtual LayoutPoint childFrameOwnerContentBoxLocation(const Frame&) const = 0;

    // Return the transformation matrix to convert a point/rect from the coordinate
    // system of the child's frame owner to this FrameView's RenderView. Note this
    // does not correspond to the absolute coordinate of this FrameView, as it doesn't
    // include the page scale transform on the RenderView (if page is scaled).
    virtual TransformationMatrix childFrameOwnerToRootContentTransform(const Frame&) const = 0;

    // Returns the transformation matrix to project from this frame view's absolute coordinate
    // to a child frame's owner renderer's local coordinate.
    virtual TransformationMatrix absoluteToChildFrameOwnerLocalTransform(const Frame&) const = 0;

private:
    ScrollableArea* enclosingScrollableArea() const final;

    bool scrollAnimatorEnabled() const final;
#if ENABLE(FORM_CONTROL_REFRESH)
    bool formControlRefreshEnabled() const final;
#endif
};

}

SPECIALIZE_TYPE_TRAITS_BEGIN(WebCore::FrameView)
static bool isType(const WebCore::Widget& widget) { return widget.isLocalFrameView() || widget.isRemoteFrameView(); }
SPECIALIZE_TYPE_TRAITS_END()
