/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "AccessibleCaret.h"

#include "AccessibleCaretLogger.h"

#include "mozilla/FloatingPoint.h"

#include "mozilla/StaticPrefs.h"

#include "mozilla/ToString.h"

#include "nsCanvasFrame.h"

#include "nsCaret.h"

#include "nsCSSFrameConstructor.h"

#include "nsDOMTokenList.h"

#include "nsIFrame.h"

#include "nsPlaceholderFrame.h"

namespace mozilla {

using namespace dom;

#undef AC_LOG

#define AC_LOG(message, ...)                                                   \

  AC_LOG_BASE("AccessibleCaret (%p): " message, this, ##__VA_ARGS__);

#undef AC_LOGV

#define AC_LOGV(message, ...)                                                  \

  AC_LOGV_BASE("AccessibleCaret (%p): " message, this, ##__VA_ARGS__);

NS_IMPL_ISUPPORTS(AccessibleCaret::DummyTouchListener, nsIDOMEventListener)

NS_NAMED_LITERAL_STRING(AccessibleCaret::sTextOverlayElementId, "text-overlay");

NS_NAMED_LITERAL_STRING(AccessibleCaret::sCaretImageElementId, "image");

#define AC_PROCESS_ENUM_TO_STREAM(e) case(e): aStream << #e; break;

std::ostream&

operator<<(std::ostream& aStream, const AccessibleCaret::Appearance& aAppearance)

{

  using Appearance = AccessibleCaret::Appearance;

  switch (aAppearance) {

    AC_PROCESS_ENUM_TO_STREAM(Appearance::None);

    AC_PROCESS_ENUM_TO_STREAM(Appearance::Normal);

    AC_PROCESS_ENUM_TO_STREAM(Appearance::NormalNotShown);

    AC_PROCESS_ENUM_TO_STREAM(Appearance::Left);

    AC_PROCESS_ENUM_TO_STREAM(Appearance::Right);

  }

  return aStream;

}

std::ostream&

operator<<(std::ostream& aStream,

           const AccessibleCaret::PositionChangedResult& aResult)

{

  using PositionChangedResult = AccessibleCaret::PositionChangedResult;

  switch (aResult) {

    AC_PROCESS_ENUM_TO_STREAM(PositionChangedResult::NotChanged);

    AC_PROCESS_ENUM_TO_STREAM(PositionChangedResult::Changed);

    AC_PROCESS_ENUM_TO_STREAM(PositionChangedResult::Invisible);

  }

  return aStream;

}

#undef AC_PROCESS_ENUM_TO_STREAM

// -----------------------------------------------------------------------------

// Implementation of AccessibleCaret methods

AccessibleCaret::AccessibleCaret(nsIPresShell* aPresShell)

  : mPresShell(aPresShell)

{

  // Check all resources required.

  if (mPresShell) {

    MOZ_ASSERT(RootFrame());

    MOZ_ASSERT(mPresShell->GetDocument());

    InjectCaretElement(mPresShell->GetDocument());

  }

}

AccessibleCaret::~AccessibleCaret()

{

  if (mPresShell) {

    RemoveCaretElement(mPresShell->GetDocument());

  }

}

void

AccessibleCaret::SetAppearance(Appearance aAppearance)

{

  if (mAppearance == aAppearance) {

    return;

  }

  ErrorResult rv;

  CaretElement().ClassList()->Remove(AppearanceString(mAppearance), rv);

  MOZ_ASSERT(!rv.Failed(), "Remove old appearance failed!");

  CaretElement().ClassList()->Add(AppearanceString(aAppearance), rv);

  MOZ_ASSERT(!rv.Failed(), "Add new appearance failed!");

  AC_LOG("%s: %s -> %s", __FUNCTION__, ToString(mAppearance).c_str(),

         ToString(aAppearance).c_str());

  mAppearance = aAppearance;

  // Need to reset rect since the cached rect will be compared in SetPosition.

  if (mAppearance == Appearance::None) {

    mImaginaryCaretRect = nsRect();

    mZoomLevel = 0.0f;

  }

}

/* static */ nsAutoString

AccessibleCaret::AppearanceString(Appearance aAppearance)

{

  nsAutoString string;

  switch (aAppearance) {

  case Appearance::None:

  case Appearance::NormalNotShown:

    string = NS_LITERAL_STRING("none");

    break;

  case Appearance::Normal:

    string = NS_LITERAL_STRING("normal");

    break;

  case Appearance::Right:

    string = NS_LITERAL_STRING("right");

    break;

  case Appearance::Left:

    string = NS_LITERAL_STRING("left");

    break;

  }

  return string;

}

bool

AccessibleCaret::Intersects(const AccessibleCaret& aCaret) const

{

  MOZ_ASSERT(mPresShell == aCaret.mPresShell);

  if (!IsVisuallyVisible() || !aCaret.IsVisuallyVisible()) {

    return false;

  }

  nsRect rect = nsLayoutUtils::GetRectRelativeToFrame(&CaretElement(), RootFrame());

  nsRect rhsRect = nsLayoutUtils::GetRectRelativeToFrame(&aCaret.CaretElement(), RootFrame());

  return rect.Intersects(rhsRect);

}

bool

AccessibleCaret::Contains(const nsPoint& aPoint, TouchArea aTouchArea) const

{

  if (!IsVisuallyVisible()) {

    return false;

  }

  nsRect textOverlayRect =

    nsLayoutUtils::GetRectRelativeToFrame(TextOverlayElement(), RootFrame());

  nsRect caretImageRect =

    nsLayoutUtils::GetRectRelativeToFrame(CaretImageElement(), RootFrame());

  if (aTouchArea == TouchArea::CaretImage) {

    return caretImageRect.Contains(aPoint);

  }

  MOZ_ASSERT(aTouchArea == TouchArea::Full, "Unexpected TouchArea type!");

  return textOverlayRect.Contains(aPoint) || caretImageRect.Contains(aPoint);

}

void

AccessibleCaret::EnsureApzAware()

{

  // If the caret element was cloned, the listener might have been lost. So

  // if that's the case we register a dummy listener if there isn't one on

  // the element already.

  if (!CaretElement().IsApzAware()) {

    // FIXME(emilio): Is this needed anymore?

    CaretElement().AddEventListener(NS_LITERAL_STRING("touchstart"),

                                    mDummyTouchListener, false);

  }

}

void

AccessibleCaret::InjectCaretElement(nsIDocument* aDocument)

{

  ErrorResult rv;

  RefPtr<Element> element = CreateCaretElement(aDocument);

  mCaretElementHolder = aDocument->InsertAnonymousContent(*element, rv);

  MOZ_ASSERT(!rv.Failed(), "Insert anonymous content should not fail!");

  MOZ_ASSERT(mCaretElementHolder, "We must have anonymous content!");

  // InsertAnonymousContent will clone the element to make an AnonymousContent.

  // Since event listeners are not being cloned when cloning a node, we need to

  // add the listener here.

  EnsureApzAware();

}

already_AddRefed<Element>

AccessibleCaret::CreateCaretElement(nsIDocument* aDocument) const

{

  // Content structure of AccessibleCaret

  // <div class="moz-accessiblecaret">  <- CaretElement()

  //   <div id="text-overlay"           <- TextOverlayElement()

  //   <div id="image">                 <- CaretImageElement()

  ErrorResult rv;

  RefPtr<Element> parent = aDocument->CreateHTMLElement(nsGkAtoms::div);

  parent->ClassList()->Add(NS_LITERAL_STRING("moz-accessiblecaret"), rv);

  parent->ClassList()->Add(NS_LITERAL_STRING("none"), rv);

  auto CreateAndAppendChildElement = [aDocument, &parent](

    const nsLiteralString& aElementId)

  {

    RefPtr<Element> child = aDocument->CreateHTMLElement(nsGkAtoms::div);

    child->SetAttr(kNameSpaceID_None, nsGkAtoms::id, aElementId, true);

    parent->AppendChildTo(child, false);

  };

  CreateAndAppendChildElement(sTextOverlayElementId);

  CreateAndAppendChildElement(sCaretImageElementId);

  return parent.forget();

}

void

AccessibleCaret::RemoveCaretElement(nsIDocument* aDocument)

{

  CaretElement().RemoveEventListener(NS_LITERAL_STRING("touchstart"),

                                     mDummyTouchListener, false);

  // FIXME(emilio): This shouldn't be needed and should be done by

  // ContentRemoved via RemoveAnonymousContent, but the current setup tears down

  // the accessible caret manager after the shell has stopped observing the

  // document, but before the frame tree has gone away. This could clearly be

  // better...

  if (nsIFrame* frame = CaretElement().GetPrimaryFrame()) {

    if (frame->HasAnyStateBits(NS_FRAME_OUT_OF_FLOW)) {

      frame = frame->GetPlaceholderFrame();

    }

    nsAutoScriptBlocker scriptBlocker;

    frame->GetParent()->RemoveFrame(nsIFrame::kPrincipalList, frame);

  }

  aDocument->RemoveAnonymousContent(*mCaretElementHolder, IgnoreErrors());

}

AccessibleCaret::PositionChangedResult

AccessibleCaret::SetPosition(nsIFrame* aFrame, int32_t aOffset)

{

  if (!CustomContentContainerFrame()) {

    return PositionChangedResult::NotChanged;

  }

  nsRect imaginaryCaretRectInFrame =

    nsCaret::GetGeometryForFrame(aFrame, aOffset, nullptr);

  imaginaryCaretRectInFrame =

    nsLayoutUtils::ClampRectToScrollFrames(aFrame, imaginaryCaretRectInFrame);

  if (imaginaryCaretRectInFrame.IsEmpty()) {

    // Don't bother to set the caret position since it's invisible.

    mImaginaryCaretRect = nsRect();

    mZoomLevel = 0.0f;

    return PositionChangedResult::Invisible;

  }

  nsRect imaginaryCaretRect = imaginaryCaretRectInFrame;

  nsLayoutUtils::TransformRect(aFrame, RootFrame(), imaginaryCaretRect);

  float zoomLevel = GetZoomLevel();

  if (imaginaryCaretRect.IsEqualEdges(mImaginaryCaretRect) &&

      FuzzyEqualsMultiplicative(zoomLevel, mZoomLevel)) {

    return PositionChangedResult::NotChanged;

  }

  mImaginaryCaretRect = imaginaryCaretRect;

  mZoomLevel = zoomLevel;

  // SetCaretElementStyle() requires the input rect relative to container frame.

  nsRect imaginaryCaretRectInContainerFrame = imaginaryCaretRectInFrame;

  nsLayoutUtils::TransformRect(aFrame, CustomContentContainerFrame(),

                               imaginaryCaretRectInContainerFrame);

  SetCaretElementStyle(imaginaryCaretRectInContainerFrame, mZoomLevel);

  return PositionChangedResult::Changed;

}

nsIFrame*

AccessibleCaret::CustomContentContainerFrame() const

{

  nsCanvasFrame* canvasFrame = mPresShell->GetCanvasFrame();

  Element* container = canvasFrame->GetCustomContentContainer();

  nsIFrame* containerFrame = container->GetPrimaryFrame();

  return containerFrame;

}

void

AccessibleCaret::SetCaretElementStyle(const nsRect& aRect, float aZoomLevel)

{

  nsPoint position = CaretElementPosition(aRect);

  nsAutoString styleStr;

  styleStr.AppendPrintf("left: %dpx; top: %dpx; "

                        "width: ",

                        nsPresContext::AppUnitsToIntCSSPixels(position.x),

                        nsPresContext::AppUnitsToIntCSSPixels(position.y));

  // We can't use AppendPrintf here, because it does locale-specific

  // formatting of floating-point values.

  styleStr.AppendFloat(StaticPrefs::layout_accessiblecaret_width() / aZoomLevel);

  styleStr.AppendLiteral("px; height: ");

  styleStr.AppendFloat(StaticPrefs::layout_accessiblecaret_height() / aZoomLevel);

  styleStr.AppendLiteral("px; margin-left: ");

  styleStr.AppendFloat(

    StaticPrefs::layout_accessiblecaret_margin_left() / aZoomLevel);

  styleStr.AppendLiteral("px");

  CaretElement().SetAttr(kNameSpaceID_None, nsGkAtoms::style, styleStr, true);

  AC_LOG("%s: %s", __FUNCTION__, NS_ConvertUTF16toUTF8(styleStr).get());

  // Set style string for children.

  SetTextOverlayElementStyle(aRect, aZoomLevel);

  SetCaretImageElementStyle(aRect, aZoomLevel);

}

void

AccessibleCaret::SetTextOverlayElementStyle(const nsRect& aRect,

                                            float aZoomLevel)

{

  nsAutoString styleStr;

  styleStr.AppendPrintf("height: %dpx;",

                        nsPresContext::AppUnitsToIntCSSPixels(aRect.height));

  TextOverlayElement()->SetAttr(kNameSpaceID_None, nsGkAtoms::style, styleStr,

                                true);

  AC_LOG("%s: %s", __FUNCTION__, NS_ConvertUTF16toUTF8(styleStr).get());

}

void

AccessibleCaret::SetCaretImageElementStyle(const nsRect& aRect,

                                           float aZoomLevel)

{

  nsAutoString styleStr;

  styleStr.AppendPrintf("margin-top: %dpx;",

                        nsPresContext::AppUnitsToIntCSSPixels(aRect.height));

  CaretImageElement()->SetAttr(kNameSpaceID_None, nsGkAtoms::style, styleStr,

                               true);

  AC_LOG("%s: %s", __FUNCTION__, NS_ConvertUTF16toUTF8(styleStr).get());

}

float

AccessibleCaret::GetZoomLevel()

{

  // Full zoom on desktop.

  float fullZoom = mPresShell->GetPresContext()->GetFullZoom();

  // Pinch-zoom on fennec.

  float resolution = mPresShell->GetCumulativeResolution();

  return fullZoom * resolution;

}

} // namespace mozilla