/* -*- 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 "nsCOMPtr.h"
#include "nsTitleBarFrame.h"
#include "nsIContent.h"
#include "mozilla/dom/Document.h"
#include "nsGkAtoms.h"
#include "nsIWidget.h"
#include "nsMenuPopupFrame.h"
#include "nsPresContext.h"
#include "nsIDocShell.h"
#include "nsPIDOMWindow.h"
#include "nsDisplayList.h"
#include "nsContentUtils.h"
#include "mozilla/MouseEvents.h"
#include "mozilla/PresShell.h"
#include "mozilla/dom/MouseEventBinding.h"

using namespace mozilla;

//
// NS_NewTitleBarFrame
//
// Creates a new TitleBar frame and returns it
//
nsIFrame* NS_NewTitleBarFrame(PresShell* aPresShell, ComputedStyle* aStyle) {
  return new (aPresShell) nsTitleBarFrame(aStyle, aPresShell->GetPresContext());
}

NS_IMPL_FRAMEARENA_HELPERS(nsTitleBarFrame)

nsTitleBarFrame::nsTitleBarFrame(ComputedStyle* aStyle,
                                 nsPresContext* aPresContext, ClassID aID)
    : nsBoxFrame(aStyle, aPresContext, aID, false) {
  mTrackingMouseMove = false;
  UpdateMouseThrough();
}

void nsTitleBarFrame::BuildDisplayListForChildren(
    nsDisplayListBuilder* aBuilder, const nsDisplayListSet& aLists) {
  // override, since we don't want children to get events
  if (aBuilder->IsForEventDelivery()) {
    if (!mContent->AsElement()->AttrValueIs(kNameSpaceID_None,
                                            nsGkAtoms::allowevents,
                                            nsGkAtoms::_true, eCaseMatters))
      return;
  }
  nsBoxFrame::BuildDisplayListForChildren(aBuilder, aLists);
}

nsresult nsTitleBarFrame::HandleEvent(nsPresContext* aPresContext,
                                      WidgetGUIEvent* aEvent,
                                      nsEventStatus* aEventStatus) {
  NS_ENSURE_ARG_POINTER(aEventStatus);
  if (nsEventStatus_eConsumeNoDefault == *aEventStatus) {
    return NS_OK;
  }

  bool doDefault = true;

  switch (aEvent->mMessage) {
    case eMouseDown: {
      if (aEvent->AsMouseEvent()->mButton == MouseButton::eLeft) {
        // titlebar has no effect in non-chrome shells
        nsCOMPtr<nsIDocShellTreeItem> dsti = aPresContext->GetDocShell();
        if (dsti) {
          if (dsti->ItemType() == nsIDocShellTreeItem::typeChrome) {
            // we're tracking.
            mTrackingMouseMove = true;

            // start capture.
            PresShell::SetCapturingContent(GetContent(),
                                           CaptureFlags::IgnoreAllowedState);

            // remember current mouse coordinates.
            mLastPoint = aEvent->mRefPoint;
          }
        }

        *aEventStatus = nsEventStatus_eConsumeNoDefault;
        doDefault = false;
      }
    } break;

    case eMouseUp: {
      if (mTrackingMouseMove &&
          aEvent->AsMouseEvent()->mButton == MouseButton::eLeft) {
        // we're done tracking.
        mTrackingMouseMove = false;

        // end capture
        PresShell::ReleaseCapturingContent();

        *aEventStatus = nsEventStatus_eConsumeNoDefault;
        doDefault = false;
      }
    } break;

    case eMouseMove: {
      if (mTrackingMouseMove) {
        LayoutDeviceIntPoint nsMoveBy = aEvent->mRefPoint - mLastPoint;

        nsIFrame* parent = GetParent();
        while (parent) {
          nsMenuPopupFrame* popupFrame = do_QueryFrame(parent);
          if (popupFrame) break;
          parent = parent->GetParent();
        }

        // if the titlebar is in a popup, move the popup frame, otherwise
        // move the widget associated with the window
        if (parent) {
          nsMenuPopupFrame* menuPopupFrame =
              static_cast<nsMenuPopupFrame*>(parent);
          nsCOMPtr<nsIWidget> widget = menuPopupFrame->GetWidget();
          LayoutDeviceIntRect bounds = widget->GetScreenBounds();

          CSSPoint cssPos = (bounds.TopLeft() + nsMoveBy) /
                            aPresContext->CSSToDevPixelScale();
          menuPopupFrame->MoveTo(RoundedToInt(cssPos), false);
        } else {
          mozilla::PresShell* presShell = aPresContext->PresShell();
          nsPIDOMWindowOuter* window = presShell->GetDocument()->GetWindow();
          if (window) {
            window->MoveBy(nsMoveBy.x, nsMoveBy.y);
          }
        }

        *aEventStatus = nsEventStatus_eConsumeNoDefault;

        doDefault = false;
      }
    } break;

    case eMouseClick: {
      WidgetMouseEvent* mouseEvent = aEvent->AsMouseEvent();
      if (mouseEvent->IsLeftClickEvent()) {
        MouseClicked(mouseEvent);
      }
      break;
    }

    default:
      break;
  }

  if (doDefault)
    return nsBoxFrame::HandleEvent(aPresContext, aEvent, aEventStatus);
  else
    return NS_OK;
}

void nsTitleBarFrame::MouseClicked(WidgetMouseEvent* aEvent) {
  // Execute the oncommand event handler.
  nsCOMPtr<nsIContent> content = mContent;
  nsContentUtils::DispatchXULCommand(
      content, false, nullptr, nullptr, aEvent->IsControl(), aEvent->IsAlt(),
      aEvent->IsShift(), aEvent->IsMeta(), aEvent->mInputSource);
}