/*
 * Copyright (C) 2014 Google 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:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * 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.
 *     * Neither the name of Google Inc. nor the names of its
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "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 THE COPYRIGHT
 * OWNER 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.
 */

#include "config.h"
#include "web/WebFrameWidgetImpl.h"

#include "core/editing/Editor.h"
#include "core/editing/FrameSelection.h"
#include "core/editing/InputMethodController.h"
#include "core/editing/PlainTextRange.h"
#include "core/frame/FrameView.h"
#include "core/frame/RemoteFrame.h"
#include "core/frame/Settings.h"
#include "core/page/EventHandler.h"
#include "core/page/FocusController.h"
#include "core/page/Page.h"
#include "core/rendering/RenderView.h"
#include "core/rendering/compositing/RenderLayerCompositor.h"
#include "platform/KeyboardCodes.h"
#include "platform/NotImplemented.h"
#include "public/web/WebBeginFrameArgs.h"
#include "public/web/WebWidgetClient.h"
#include "web/WebInputEventConversion.h"
#include "web/WebLocalFrameImpl.h"
#include "web/WebPluginContainerImpl.h"
#include "web/WebRemoteFrameImpl.h"
#include "web/WebViewImpl.h"

namespace blink {

// WebFrameWidget ----------------------------------------------------------------

WebFrameWidget* WebFrameWidget::create(WebWidgetClient* client, WebLocalFrame* localRoot)
{
    // Pass the WebFrameWidget's self-reference to the caller.
    return WebFrameWidgetImpl::create(client, localRoot);
}

WebFrameWidgetImpl* WebFrameWidgetImpl::create(WebWidgetClient* client, WebLocalFrame* localRoot)
{
    // Pass the WebFrameWidgetImpl's self-reference to the caller.
    return adoptRef(new WebFrameWidgetImpl(client, localRoot)).leakRef();
}

WebFrameWidgetImpl::WebFrameWidgetImpl(WebWidgetClient* client, WebLocalFrame* localRoot)
    : m_client(client)
    , m_localRoot(toWebLocalFrameImpl(localRoot))
    , m_layerTreeView(nullptr)
    , m_rootLayer(nullptr)
    , m_rootGraphicsLayer(nullptr)
    , m_isAcceleratedCompositingActive(false)
    , m_layerTreeViewClosed(false)
    , m_webView(m_localRoot->viewImpl())
    , m_page(m_webView->page())
    , m_suppressNextKeypressEvent(false)
    , m_ignoreInputEvents(false)
{
    ASSERT(m_localRoot->frame()->isLocalRoot());
    initializeLayerTreeView();
    m_localRoot->setFrameWidget(this);
}

WebFrameWidgetImpl::~WebFrameWidgetImpl()
{
}

// WebWidget ------------------------------------------------------------------

void WebFrameWidgetImpl::close()
{
    // Reset the delegate to prevent notifications being sent as we're being
    // deleted.
    m_client = nullptr;

    deref(); // Balances ref() acquired in WebFrameWidget::create
}

WebSize WebFrameWidgetImpl::size()
{
    return m_size;
}

void WebFrameWidgetImpl::willStartLiveResize()
{
    if (m_localRoot->frameView())
        m_localRoot->frameView()->willStartLiveResize();

    LocalFrame* frame = m_localRoot->frame();
    WebPluginContainerImpl* pluginContainer = WebLocalFrameImpl::pluginContainerFromFrame(frame);
    if (pluginContainer)
        pluginContainer->willStartLiveResize();
}

void WebFrameWidgetImpl::resize(const WebSize& newSize)
{
    if (m_size == newSize)
        return;

    FrameView* view = m_localRoot->frameView();
    if (!view)
        return;

    m_size = newSize;

    updateMainFrameLayoutSize();

    view->resize(m_size);

    // FIXME: In WebViewImpl this layout was a precursor to setting the minimum scale limit.
    // It is not clear if this is necessary for frame-level widget resize.
    if (view->needsLayout())
        view->layout();

    // FIXME: Investigate whether this is needed; comment from eseidel suggests that this function
    // is flawed.
    sendResizeEventAndRepaint();
}

void WebFrameWidgetImpl::sendResizeEventAndRepaint()
{
    // FIXME: This is wrong. The FrameView is responsible sending a resizeEvent
    // as part of layout. Layout is also responsible for sending invalidations
    // to the embedder. This method and all callers may be wrong. -- eseidel.
    if (m_localRoot->frameView()) {
        // Enqueues the resize event.
        m_localRoot->frame()->document()->enqueueResizeEvent();
    }

    if (m_client) {
        if (isAcceleratedCompositingActive()) {
            updateLayerTreeViewport();
        } else {
            WebRect damagedRect(0, 0, m_size.width, m_size.height);
            m_client->didInvalidateRect(damagedRect);
        }
    }
}

void WebFrameWidgetImpl::resizePinchViewport(const WebSize& newSize)
{
    // FIXME: Implement pinch viewport for out-of-process iframes.
}

void WebFrameWidgetImpl::updateMainFrameLayoutSize()
{
    if (!m_localRoot)
        return;

    RefPtrWillBeRawPtr<FrameView> view = m_localRoot->frameView();
    if (!view)
        return;

    WebSize layoutSize = m_size;

    view->setLayoutSize(layoutSize);
}

void WebFrameWidgetImpl::willEndLiveResize()
{
    if (m_localRoot->frameView())
        m_localRoot->frameView()->willEndLiveResize();

    LocalFrame* frame = m_localRoot->frame();
    WebPluginContainerImpl* pluginContainer = WebLocalFrameImpl::pluginContainerFromFrame(frame);
    if (pluginContainer)
        pluginContainer->willEndLiveResize();
}

void WebFrameWidgetImpl::willEnterFullScreen()
{
    // FIXME: Implement full screen for out-of-process iframes.
}

void WebFrameWidgetImpl::didEnterFullScreen()
{
    // FIXME: Implement full screen for out-of-process iframes.
}

void WebFrameWidgetImpl::willExitFullScreen()
{
    // FIXME: Implement full screen for out-of-process iframes.
}

void WebFrameWidgetImpl::didExitFullScreen()
{
    // FIXME: Implement full screen for out-of-process iframes.
}

void WebFrameWidgetImpl::beginFrame(const WebBeginFrameArgs& frameTime)
{
    TRACE_EVENT0("blink", "WebFrameWidgetImpl::beginFrame");

    WebBeginFrameArgs validFrameTime(frameTime);
    if (!validFrameTime.lastFrameTimeMonotonic)
        validFrameTime.lastFrameTimeMonotonic = monotonicallyIncreasingTime();

    PageWidgetDelegate::animate(*m_page, validFrameTime.lastFrameTimeMonotonic, *m_localRoot->frame());
}

void WebFrameWidgetImpl::layout()
{
    TRACE_EVENT0("blink", "WebFrameWidgetImpl::layout");
    if (!m_localRoot)
        return;

    PageWidgetDelegate::layout(*m_page, *m_localRoot->frame());
    updateLayerTreeBackgroundColor();
}

void WebFrameWidgetImpl::paint(WebCanvas* canvas, const WebRect& rect)
{
    // Out-of-process iframes require compositing.
    ASSERT_NOT_REACHED();
}


void WebFrameWidgetImpl::updateLayerTreeViewport()
{
    if (!page() || !m_layerTreeView)
        return;

    // FIXME: We need access to page scale information from the WebView.
    m_layerTreeView->setPageScaleFactorAndLimits(1, 1, 1);
}

void WebFrameWidgetImpl::updateLayerTreeBackgroundColor()
{
    if (!m_layerTreeView)
        return;

    m_layerTreeView->setBackgroundColor(alphaChannel(m_webView->backgroundColorOverride()) ? m_webView->backgroundColorOverride() : m_webView->backgroundColor());
}

void WebFrameWidgetImpl::updateLayerTreeDeviceScaleFactor()
{
    ASSERT(page());
    ASSERT(m_layerTreeView);

    float deviceScaleFactor = page()->deviceScaleFactor();
    m_layerTreeView->setDeviceScaleFactor(deviceScaleFactor);
}

bool WebFrameWidgetImpl::isTransparent() const
{
    // FIXME: This might need to proxy to the WebView's isTransparent().
    return false;
}

void WebFrameWidgetImpl::compositeAndReadbackAsync(WebCompositeAndReadbackAsyncCallback* callback)
{
    m_layerTreeView->compositeAndReadbackAsync(callback);
}

bool WebFrameWidgetImpl::isTrackingRepaints() const
{
    return m_localRoot->frameView()->isTrackingPaintInvalidations();
}

void WebFrameWidgetImpl::themeChanged()
{
    FrameView* view = m_localRoot->frameView();

    WebRect damagedRect(0, 0, m_size.width, m_size.height);
    view->invalidateRect(damagedRect);
}

const WebInputEvent* WebFrameWidgetImpl::m_currentInputEvent = nullptr;

// FIXME: autogenerate this kind of code, and use it throughout Blink rather than
// the one-offs for subsets of these values.
static String inputTypeToName(WebInputEvent::Type type)
{
    switch (type) {
    case WebInputEvent::MouseDown:
        return EventTypeNames::mousedown;
    case WebInputEvent::MouseUp:
        return EventTypeNames::mouseup;
    case WebInputEvent::MouseMove:
        return EventTypeNames::mousemove;
    case WebInputEvent::MouseEnter:
        return EventTypeNames::mouseenter;
    case WebInputEvent::MouseLeave:
        return EventTypeNames::mouseleave;
    case WebInputEvent::ContextMenu:
        return EventTypeNames::contextmenu;
    case WebInputEvent::MouseWheel:
        return EventTypeNames::mousewheel;
    case WebInputEvent::KeyDown:
        return EventTypeNames::keydown;
    case WebInputEvent::KeyUp:
        return EventTypeNames::keyup;
    case WebInputEvent::GestureScrollBegin:
        return EventTypeNames::gesturescrollstart;
    case WebInputEvent::GestureScrollEnd:
        return EventTypeNames::gesturescrollend;
    case WebInputEvent::GestureScrollUpdate:
        return EventTypeNames::gesturescrollupdate;
    case WebInputEvent::GestureTapDown:
        return EventTypeNames::gesturetapdown;
    case WebInputEvent::GestureShowPress:
        return EventTypeNames::gestureshowpress;
    case WebInputEvent::GestureTap:
        return EventTypeNames::gesturetap;
    case WebInputEvent::GestureTapUnconfirmed:
        return EventTypeNames::gesturetapunconfirmed;
    case WebInputEvent::TouchStart:
        return EventTypeNames::touchstart;
    case WebInputEvent::TouchMove:
        return EventTypeNames::touchmove;
    case WebInputEvent::TouchEnd:
        return EventTypeNames::touchend;
    case WebInputEvent::TouchCancel:
        return EventTypeNames::touchcancel;
    default:
        return String("unknown");
    }
}

bool WebFrameWidgetImpl::handleInputEvent(const WebInputEvent& inputEvent)
{

    TRACE_EVENT1("input", "WebFrameWidgetImpl::handleInputEvent", "type", inputTypeToName(inputEvent.type).ascii());

    // Report the event to be NOT processed by WebKit, so that the browser can handle it appropriately.
    if (m_ignoreInputEvents)
        return false;

    TemporaryChange<const WebInputEvent*> currentEventChange(m_currentInputEvent, &inputEvent);

    if (m_mouseCaptureNode && WebInputEvent::isMouseEventType(inputEvent.type)) {
        TRACE_EVENT1("input", "captured mouse event", "type", inputEvent.type);
        // Save m_mouseCaptureNode since mouseCaptureLost() will clear it.
        RefPtrWillBeRawPtr<Node> node = m_mouseCaptureNode;

        // Not all platforms call mouseCaptureLost() directly.
        if (inputEvent.type == WebInputEvent::MouseUp)
            mouseCaptureLost();

        OwnPtr<UserGestureIndicator> gestureIndicator;

        AtomicString eventType;
        switch (inputEvent.type) {
        case WebInputEvent::MouseMove:
            eventType = EventTypeNames::mousemove;
            break;
        case WebInputEvent::MouseLeave:
            eventType = EventTypeNames::mouseout;
            break;
        case WebInputEvent::MouseDown:
            eventType = EventTypeNames::mousedown;
            gestureIndicator = adoptPtr(new UserGestureIndicator(DefinitelyProcessingNewUserGesture));
            m_mouseCaptureGestureToken = gestureIndicator->currentToken();
            break;
        case WebInputEvent::MouseUp:
            eventType = EventTypeNames::mouseup;
            gestureIndicator = adoptPtr(new UserGestureIndicator(m_mouseCaptureGestureToken.release()));
            break;
        default:
            ASSERT_NOT_REACHED();
        }

        node->dispatchMouseEvent(
            PlatformMouseEventBuilder(m_localRoot->frameView(), static_cast<const WebMouseEvent&>(inputEvent)),
            eventType, static_cast<const WebMouseEvent&>(inputEvent).clickCount);
        return true;
    }

    return PageWidgetDelegate::handleInputEvent(*this, inputEvent, m_localRoot->frame());
}

void WebFrameWidgetImpl::setCursorVisibilityState(bool isVisible)
{
    m_page->setIsCursorVisible(isVisible);
}

bool WebFrameWidgetImpl::hasTouchEventHandlersAt(const WebPoint& point)
{
    // FIXME: Implement this. Note that the point must be divided by pageScaleFactor.
    return true;
}

void WebFrameWidgetImpl::scheduleAnimation()
{
    if (m_layerTreeView) {
        m_layerTreeView->setNeedsAnimate();
        return;
    }
    if (m_client)
        m_client->scheduleAnimation();
}

void WebFrameWidgetImpl::applyViewportDeltas(
    const WebSize& pinchViewportDelta,
    const WebSize& mainFrameDelta,
    const WebFloatSize& elasticOverscrollDelta,
    float pageScaleDelta,
    float topControlsDelta)
{
    // FIXME: To be implemented.
}

void WebFrameWidgetImpl::applyViewportDeltas(const WebSize& scrollDelta, float pageScaleDelta, float topControlsDelta)
{
    // FIXME: To be implemented.
}

void WebFrameWidgetImpl::mouseCaptureLost()
{
    TRACE_EVENT_ASYNC_END0("input", "capturing mouse", this);
    m_mouseCaptureNode = nullptr;
}

void WebFrameWidgetImpl::setFocus(bool enable)
{
    m_page->focusController().setFocused(enable);
    if (enable) {
        m_page->focusController().setActive(true);
        RefPtrWillBeRawPtr<Frame> focusedFrame = m_page->focusController().focusedFrame();
        if (focusedFrame && focusedFrame->isLocalFrame()) {
            LocalFrame* localFrame = toLocalFrame(focusedFrame.get());
            Element* element = localFrame->document()->focusedElement();
            if (element && localFrame->selection().selection().isNone()) {
                // If the selection was cleared while the WebView was not
                // focused, then the focus element shows with a focus ring but
                // no caret and does respond to keyboard inputs.
                if (element->isTextFormControl()) {
                    element->updateFocusAppearance(true);
                } else if (element->isContentEditable()) {
                    // updateFocusAppearance() selects all the text of
                    // contentseditable DIVs. So we set the selection explicitly
                    // instead. Note that this has the side effect of moving the
                    // caret back to the beginning of the text.
                    Position position(element, 0, Position::PositionIsOffsetInAnchor);
                    localFrame->selection().setSelection(VisibleSelection(position, SEL_DEFAULT_AFFINITY));
                }
            }
        }
    }
}

bool WebFrameWidgetImpl::setComposition(
    const WebString& text,
    const WebVector<WebCompositionUnderline>& underlines,
    int selectionStart,
    int selectionEnd)
{
    // FIXME: To be implemented.
    return false;
}

bool WebFrameWidgetImpl::confirmComposition()
{
    // FIXME: To be implemented.
    return false;
}

bool WebFrameWidgetImpl::confirmComposition(ConfirmCompositionBehavior selectionBehavior)
{
    // FIXME: To be implemented.
    return false;
}

bool WebFrameWidgetImpl::confirmComposition(const WebString& text)
{
    // FIXME: To be implemented.
    return false;
}

bool WebFrameWidgetImpl::compositionRange(size_t* location, size_t* length)
{
    // FIXME: To be implemented.
    return false;
}

WebTextInputInfo WebFrameWidgetImpl::textInputInfo()
{
    WebTextInputInfo info;
    // FIXME: To be implemented.
    return info;
}

WebColor WebFrameWidgetImpl::backgroundColor() const
{
    if (isTransparent())
        return Color::transparent;
    if (!m_localRoot->frameView())
        return m_webView->backgroundColor();
    FrameView* view = m_localRoot->frameView();
    return view->documentBackgroundColor().rgb();
}

bool WebFrameWidgetImpl::selectionBounds(WebRect& anchor, WebRect& focus) const
{
    const Frame* frame = focusedCoreFrame();
    if (!frame || !frame->isLocalFrame())
        return false;

    const LocalFrame* localFrame = toLocalFrame(frame);
    if (!localFrame)
        return false;
    FrameSelection& selection = localFrame->selection();

    if (selection.isCaret()) {
        anchor = focus = selection.absoluteCaretBounds();
    } else {
        RefPtrWillBeRawPtr<Range> selectedRange = selection.toNormalizedRange();
        if (!selectedRange)
            return false;

        RefPtrWillBeRawPtr<Range> range(Range::create(selectedRange->startContainer()->document(),
            selectedRange->startContainer(),
            selectedRange->startOffset(),
            selectedRange->startContainer(),
            selectedRange->startOffset()));
        anchor = localFrame->editor().firstRectForRange(range.get());

        range = Range::create(selectedRange->endContainer()->document(),
            selectedRange->endContainer(),
            selectedRange->endOffset(),
            selectedRange->endContainer(),
            selectedRange->endOffset());
        focus = localFrame->editor().firstRectForRange(range.get());
    }

    IntRect scaledAnchor(localFrame->view()->contentsToWindow(anchor));
    IntRect scaledFocus(localFrame->view()->contentsToWindow(focus));

    anchor = scaledAnchor;
    focus = scaledFocus;

    if (!selection.selection().isBaseFirst())
        std::swap(anchor, focus);
    return true;
}

bool WebFrameWidgetImpl::selectionTextDirection(WebTextDirection& start, WebTextDirection& end) const
{
    if (!focusedCoreFrame()->isLocalFrame())
        return false;
    const LocalFrame* frame = toLocalFrame(focusedCoreFrame());
    if (!frame)
        return false;
    FrameSelection& selection = frame->selection();
    if (!selection.toNormalizedRange())
        return false;
    start = toWebTextDirection(selection.start().primaryDirection());
    end = toWebTextDirection(selection.end().primaryDirection());
    return true;
}

bool WebFrameWidgetImpl::isSelectionAnchorFirst() const
{
    if (!focusedCoreFrame()->isLocalFrame())
        return false;
    if (const LocalFrame* frame = toLocalFrame(focusedCoreFrame()))
        return frame->selection().selection().isBaseFirst();
    return false;
}

bool WebFrameWidgetImpl::caretOrSelectionRange(size_t* location, size_t* length)
{
    if (!focusedCoreFrame()->isLocalFrame())
        return false;
    const LocalFrame* focused = toLocalFrame(focusedCoreFrame());
    if (!focused)
        return false;

    PlainTextRange selectionOffsets = focused->inputMethodController().getSelectionOffsets();
    if (selectionOffsets.isNull())
        return false;

    *location = selectionOffsets.start();
    *length = selectionOffsets.length();
    return true;
}

void WebFrameWidgetImpl::setTextDirection(WebTextDirection direction)
{
    // The Editor::setBaseWritingDirection() function checks if we can change
    // the text direction of the selected node and updates its DOM "dir"
    // attribute and its CSS "direction" property.
    // So, we just call the function as Safari does.
    if (!focusedCoreFrame()->isLocalFrame())
        return;
    const LocalFrame* focused = toLocalFrame(focusedCoreFrame());
    if (!focused)
        return;

    Editor& editor = focused->editor();
    if (!editor.canEdit())
        return;

    switch (direction) {
    case WebTextDirectionDefault:
        editor.setBaseWritingDirection(NaturalWritingDirection);
        break;

    case WebTextDirectionLeftToRight:
        editor.setBaseWritingDirection(LeftToRightWritingDirection);
        break;

    case WebTextDirectionRightToLeft:
        editor.setBaseWritingDirection(RightToLeftWritingDirection);
        break;

    default:
        notImplemented();
        break;
    }
}

bool WebFrameWidgetImpl::isAcceleratedCompositingActive() const
{
    return m_isAcceleratedCompositingActive;
}

void WebFrameWidgetImpl::willCloseLayerTreeView()
{
    setIsAcceleratedCompositingActive(false);
    m_layerTreeView = nullptr;
    m_layerTreeViewClosed = true;
}

void WebFrameWidgetImpl::didChangeWindowResizerRect()
{
    if (m_localRoot->frameView())
        m_localRoot->frameView()->windowResizerRectChanged();
}

void WebFrameWidgetImpl::handleMouseLeave(LocalFrame& mainFrame, const WebMouseEvent& event)
{
    // FIXME: WebWidget doesn't have the method below.
    // m_client->setMouseOverURL(WebURL());
    PageWidgetEventHandler::handleMouseLeave(mainFrame, event);
}

void WebFrameWidgetImpl::handleMouseDown(LocalFrame& mainFrame, const WebMouseEvent& event)
{
    // Take capture on a mouse down on a plugin so we can send it mouse events.
    // If the hit node is a plugin but a scrollbar is over it don't start mouse
    // capture because it will interfere with the scrollbar receiving events.
    IntPoint point(event.x, event.y);
    if (event.button == WebMouseEvent::ButtonLeft) {
        point = m_localRoot->frameView()->windowToContents(point);
        HitTestResult result(m_localRoot->frame()->eventHandler().hitTestResultAtPoint(point));
        result.setToShadowHostIfInUserAgentShadowRoot();
        Node* hitNode = result.innerNonSharedNode();

        if (!result.scrollbar() && hitNode && hitNode->renderer() && hitNode->renderer()->isEmbeddedObject()) {
            m_mouseCaptureNode = hitNode;
            TRACE_EVENT_ASYNC_BEGIN0("input", "capturing mouse", this);
        }
    }

    PageWidgetEventHandler::handleMouseDown(mainFrame, event);

    if (event.button == WebMouseEvent::ButtonLeft && m_mouseCaptureNode)
        m_mouseCaptureGestureToken = mainFrame.eventHandler().takeLastMouseDownGestureToken();

    // FIXME: Add context menu support.
}

void WebFrameWidgetImpl::handleMouseUp(LocalFrame& mainFrame, const WebMouseEvent& event)
{
    PageWidgetEventHandler::handleMouseUp(mainFrame, event);

    // FIXME: Add context menu support (Windows).
}

bool WebFrameWidgetImpl::handleMouseWheel(LocalFrame& mainFrame, const WebMouseWheelEvent& event)
{
    return PageWidgetEventHandler::handleMouseWheel(mainFrame, event);
}

bool WebFrameWidgetImpl::handleGestureEvent(const WebGestureEvent& event)
{
    // FIXME: Add gesture support.
    return false;
}

bool WebFrameWidgetImpl::handleKeyEvent(const WebKeyboardEvent& event)
{
    ASSERT((event.type == WebInputEvent::RawKeyDown)
        || (event.type == WebInputEvent::KeyDown)
        || (event.type == WebInputEvent::KeyUp));

    // Please refer to the comments explaining the m_suppressNextKeypressEvent
    // member.
    // The m_suppressNextKeypressEvent is set if the KeyDown is handled by
    // Webkit. A keyDown event is typically associated with a keyPress(char)
    // event and a keyUp event. We reset this flag here as this is a new keyDown
    // event.
    m_suppressNextKeypressEvent = false;

    RefPtrWillBeRawPtr<Frame> focusedFrame = focusedCoreFrame();
    if (focusedFrame && focusedFrame->isRemoteFrame()) {
        WebRemoteFrameImpl* webFrame = WebRemoteFrameImpl::fromFrame(*toRemoteFrame(focusedFrame.get()));
        webFrame->client()->forwardInputEvent(&event);
        return true;
    }

    if (!focusedFrame || !focusedFrame->isLocalFrame())
        return false;

    RefPtrWillBeRawPtr<LocalFrame> frame = toLocalFrame(focusedFrame.get());

    PlatformKeyboardEventBuilder evt(event);

    if (frame->eventHandler().keyEvent(evt)) {
        if (WebInputEvent::RawKeyDown == event.type) {
            // Suppress the next keypress event unless the focused node is a plug-in node.
            // (Flash needs these keypress events to handle non-US keyboards.)
            Element* element = focusedElement();
            if (!element || !element->renderer() || !element->renderer()->isEmbeddedObject())
                m_suppressNextKeypressEvent = true;
        }
        return true;
    }

    return keyEventDefault(event);
}

bool WebFrameWidgetImpl::handleCharEvent(const WebKeyboardEvent& event)
{
    ASSERT(event.type == WebInputEvent::Char);

    // Please refer to the comments explaining the m_suppressNextKeypressEvent
    // member.  The m_suppressNextKeypressEvent is set if the KeyDown is
    // handled by Webkit. A keyDown event is typically associated with a
    // keyPress(char) event and a keyUp event. We reset this flag here as it
    // only applies to the current keyPress event.
    bool suppress = m_suppressNextKeypressEvent;
    m_suppressNextKeypressEvent = false;

    LocalFrame* frame = toLocalFrame(focusedCoreFrame());
    if (!frame)
        return suppress;

    EventHandler& handler = frame->eventHandler();

    PlatformKeyboardEventBuilder evt(event);
    if (!evt.isCharacterKey())
        return true;

    // Accesskeys are triggered by char events and can't be suppressed.
    if (handler.handleAccessKey(evt))
        return true;

    // Safari 3.1 does not pass off windows system key messages (WM_SYSCHAR) to
    // the eventHandler::keyEvent. We mimic this behavior on all platforms since
    // for now we are converting other platform's key events to windows key
    // events.
    if (evt.isSystemKey())
        return false;

    if (!suppress && !handler.keyEvent(evt))
        return keyEventDefault(event);

    return true;
}


bool WebFrameWidgetImpl::keyEventDefault(const WebKeyboardEvent& event)
{
    LocalFrame* frame = toLocalFrame(focusedCoreFrame());
    if (!frame)
        return false;

    switch (event.type) {
    case WebInputEvent::Char:
        if (event.windowsKeyCode == VKEY_SPACE) {
            int keyCode = ((event.modifiers & WebInputEvent::ShiftKey) ? VKEY_PRIOR : VKEY_NEXT);
            return scrollViewWithKeyboard(keyCode, event.modifiers);
        }
        break;
    case WebInputEvent::RawKeyDown:
        if (event.modifiers == WebInputEvent::ControlKey) {
            switch (event.windowsKeyCode) {
#if !OS(MACOSX)
            case 'A':
                WebFrame::fromFrame(focusedCoreFrame())->executeCommand(WebString::fromUTF8("SelectAll"));
                return true;
            case VKEY_INSERT:
            case 'C':
                WebFrame::fromFrame(focusedCoreFrame())->executeCommand(WebString::fromUTF8("Copy"));
                return true;
#endif
            // Match FF behavior in the sense that Ctrl+home/end are the only Ctrl
            // key combinations which affect scrolling. Safari is buggy in the
            // sense that it scrolls the page for all Ctrl+scrolling key
            // combinations. For e.g. Ctrl+pgup/pgdn/up/down, etc.
            case VKEY_HOME:
            case VKEY_END:
                break;
            default:
                return false;
            }
        }
        if (!event.isSystemKey && !(event.modifiers & WebInputEvent::ShiftKey))
            return scrollViewWithKeyboard(event.windowsKeyCode, event.modifiers);
        break;
    default:
        break;
    }
    return false;
}

bool WebFrameWidgetImpl::scrollViewWithKeyboard(int keyCode, int modifiers)
{
    ScrollDirection scrollDirection;
    ScrollGranularity scrollGranularity;
#if OS(MACOSX)
    // Control-Up/Down should be PageUp/Down on Mac.
    if (modifiers & WebMouseEvent::ControlKey) {
        if (keyCode == VKEY_UP)
            keyCode = VKEY_PRIOR;
        else if (keyCode == VKEY_DOWN)
            keyCode = VKEY_NEXT;
    }
#endif
    if (!mapKeyCodeForScroll(keyCode, &scrollDirection, &scrollGranularity))
        return false;

    if (LocalFrame* frame = toLocalFrame(focusedCoreFrame()))
        return frame->eventHandler().bubblingScroll(scrollDirection, scrollGranularity);
    return false;
}

bool WebFrameWidgetImpl::mapKeyCodeForScroll(
    int keyCode,
    ScrollDirection* scrollDirection,
    ScrollGranularity* scrollGranularity)
{
    switch (keyCode) {
    case VKEY_LEFT:
        *scrollDirection = ScrollLeft;
        *scrollGranularity = ScrollByLine;
        break;
    case VKEY_RIGHT:
        *scrollDirection = ScrollRight;
        *scrollGranularity = ScrollByLine;
        break;
    case VKEY_UP:
        *scrollDirection = ScrollUp;
        *scrollGranularity = ScrollByLine;
        break;
    case VKEY_DOWN:
        *scrollDirection = ScrollDown;
        *scrollGranularity = ScrollByLine;
        break;
    case VKEY_HOME:
        *scrollDirection = ScrollUp;
        *scrollGranularity = ScrollByDocument;
        break;
    case VKEY_END:
        *scrollDirection = ScrollDown;
        *scrollGranularity = ScrollByDocument;
        break;
    case VKEY_PRIOR: // page up
        *scrollDirection = ScrollUp;
        *scrollGranularity = ScrollByPage;
        break;
    case VKEY_NEXT: // page down
        *scrollDirection = ScrollDown;
        *scrollGranularity = ScrollByPage;
        break;
    default:
        return false;
    }

    return true;
}

Frame* WebFrameWidgetImpl::focusedCoreFrame() const
{
    return m_page ? m_page->focusController().focusedOrMainFrame() : nullptr;
}

Element* WebFrameWidgetImpl::focusedElement() const
{
    Frame* frame = m_page->focusController().focusedFrame();
    if (!frame || !frame->isLocalFrame())
        return nullptr;

    Document* document = toLocalFrame(frame)->document();
    if (!document)
        return nullptr;

    return document->focusedElement();
}

void WebFrameWidgetImpl::initializeLayerTreeView()
{
    if (m_client) {
        m_client->initializeLayerTreeView();
        m_layerTreeView = m_client->layerTreeView();
    }

    m_page->settings().setAcceleratedCompositingEnabled(m_layerTreeView);

    // FIXME: only unittests, click to play, Android priting, and printing (for headers and footers)
    // make this assert necessary. We should make them not hit this code and then delete allowsBrokenNullLayerTreeView.
    ASSERT(m_layerTreeView || !m_client || m_client->allowsBrokenNullLayerTreeView());
}

void WebFrameWidgetImpl::setIsAcceleratedCompositingActive(bool active)
{
    // In the middle of shutting down; don't try to spin back up a compositor.
    // FIXME: compositing startup/shutdown should be refactored so that it
    // turns on explicitly rather than lazily, which causes this awkwardness.
    if (m_layerTreeViewClosed)
        return;

    ASSERT(!active || m_layerTreeView);

    if (m_isAcceleratedCompositingActive == active)
        return;

    if (!m_client)
        return;

    if (active) {
        TRACE_EVENT0("blink", "WebViewImpl::setIsAcceleratedCompositingActive(true)");
        m_layerTreeView->setRootLayer(*m_rootLayer);

        bool visible = page()->visibilityState() == PageVisibilityStateVisible;
        m_layerTreeView->setVisible(visible);
        updateLayerTreeDeviceScaleFactor();
        updateLayerTreeBackgroundColor();
        m_layerTreeView->setHasTransparentBackground(isTransparent());
        updateLayerTreeViewport();
        m_isAcceleratedCompositingActive = true;
    }
    if (m_localRoot->frameView())
        m_localRoot->frameView()->setClipsRepaints(!m_isAcceleratedCompositingActive);
}

RenderLayerCompositor* WebFrameWidgetImpl::compositor() const
{
    LocalFrame* frame = toLocalFrame(toCoreFrame(m_localRoot));
    if (!frame || !frame->document() || !frame->document()->renderView())
        return nullptr;

    return frame->document()->renderView()->compositor();
}

void WebFrameWidgetImpl::suppressInvalidations(bool enable)
{
    if (m_client)
        m_client->suppressCompositorScheduling(enable);
}

void WebFrameWidgetImpl::setRootGraphicsLayer(GraphicsLayer* layer)
{
    suppressInvalidations(true);

    m_rootGraphicsLayer = layer;
    m_rootLayer = layer ? layer->platformLayer() : nullptr;

    setIsAcceleratedCompositingActive(layer);

    if (m_layerTreeView) {
        if (m_rootLayer) {
            m_layerTreeView->setRootLayer(*m_rootLayer);
            // We register viewport layers here since there may not be a layer
            // tree view prior to this point.
            GraphicsLayer* rootScrollLayer = compositor()->scrollLayer();
            ASSERT(rootScrollLayer);
            WebLayer* pageScaleLayer = rootScrollLayer->parent() ? rootScrollLayer->parent()->platformLayer() : nullptr;
            m_layerTreeView->registerViewportLayers(nullptr, pageScaleLayer, rootScrollLayer->platformLayer(), nullptr);
        } else {
            m_layerTreeView->clearRootLayer();
            m_layerTreeView->clearViewportLayers();
        }
    }

    suppressInvalidations(false);
}

} // namespace blink