text: /*
   * Copyright (C) 2006, 2007, 2008, 2010 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 COMPUTER, 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 COMPUTER, INC. OR
   * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   * 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 "ImageDocument.h"
  
  #include "CachedImage.h"
  #include "DocumentLoader.h"
  #include "EventListener.h"
  #include "EventNames.h"
  #include "Frame.h"
  #include "FrameLoaderClient.h"
  #include "FrameView.h"
  #include "HTMLHtmlElement.h"
  #include "HTMLImageElement.h"
  #include "HTMLNames.h"
  #include "LocalizedStrings.h"
  #include "MouseEvent.h"
  #include "NotImplemented.h"
  #include "Page.h"
  #include "RawDataDocumentParser.h"
  #include "Settings.h"
  
  using std::min;
  
  namespace WebCore {
  
  using namespace HTMLNames;
  
  class ImageEventListener : public EventListener {
  public:
      static PassRefPtr<ImageEventListener> create(ImageDocument* document) { return adoptRef(new ImageEventListener(document)); }
      static const ImageEventListener* cast(const EventListener* listener)
      {
          return listener->type() == ImageEventListenerType
              ? static_cast<const ImageEventListener*>(listener)
              : 0;
      }
  
      virtual bool operator==(const EventListener& other);
  
  private:
      ImageEventListener(ImageDocument* document)
          : EventListener(ImageEventListenerType)
          , m_doc(document)
      {
      }
  
      virtual void handleEvent(ScriptExecutionContext*, Event*);
  
      ImageDocument* m_doc;
  };
      
  class ImageDocumentParser : public RawDataDocumentParser {
  public:
      static PassRefPtr<ImageDocumentParser> create(ImageDocument* document)
      {
          return adoptRef(new ImageDocumentParser(document));
      }
  
      ImageDocument* document() const
      {
          return static_cast<ImageDocument*>(RawDataDocumentParser::document());
      }
      
  private:
      ImageDocumentParser(ImageDocument* document)
          : RawDataDocumentParser(document)
      {
      }
  
      virtual void appendBytes(DocumentWriter*, const char*, size_t);
      virtual void finish();
  };
  
  class ImageDocumentElement : public HTMLImageElement {
  public:
      static PassRefPtr<ImageDocumentElement> create(ImageDocument*);
  
  private:
      ImageDocumentElement(ImageDocument* document)
          : HTMLImageElement(imgTag, document)
          , m_imageDocument(document)
      {
      }
  
      virtual ~ImageDocumentElement();
      virtual void didMoveToNewDocument(Document* oldDocument) OVERRIDE;
  
      ImageDocument* m_imageDocument;
  };
  
  inline PassRefPtr<ImageDocumentElement> ImageDocumentElement::create(ImageDocument* document)
  {
      return adoptRef(new ImageDocumentElement(document));
  }
  
  // --------
  
  static float pageZoomFactor(const Document* document)
  {
      Frame* frame = document->frame();
      return frame ? frame->pageZoomFactor() : 1;
  }
  
  void ImageDocumentParser::appendBytes(DocumentWriter*, const char*, size_t)
  {
      Frame* frame = document()->frame();
      Settings* settings = frame->settings();
      if (!frame->loader()->client()->allowImage(!settings || settings->areImagesEnabled(), document()->url()))
          return;
  
      CachedImage* cachedImage = document()->cachedImage();
      cachedImage->data(frame->loader()->documentLoader()->mainResourceData(), false);
  
      document()->imageUpdated();
  }
  
  void ImageDocumentParser::finish()
  {
      if (!isStopped() && document()->imageElement()) {
          CachedImage* cachedImage = document()->cachedImage();
          RefPtr<SharedBuffer> data = document()->frame()->loader()->documentLoader()->mainResourceData();
  
          // If this is a multipart image, make a copy of the current part, since the resource data
          // will be overwritten by the next part.
          if (document()->frame()->loader()->documentLoader()->isLoadingMultipartContent())
              data = data->copy();
  
          cachedImage->data(data.release(), true);
          cachedImage->finish();
  
          cachedImage->setResponse(document()->frame()->loader()->documentLoader()->response());
  
          // Report the natural image size in the page title, regardless of zoom
          // level.
          LayoutSize size = cachedImage->imageSizeForRenderer(document()->imageElement()->renderer(), 1.0f);
          if (size.width()) {
              // Compute the title, we use the decoded filename of the resource, falling
              // back on the (decoded) hostname if there is no path.
              String fileName = decodeURLEscapeSequences(document()->url().lastPathComponent());
              if (fileName.isEmpty())
                  fileName = document()->url().host();
              document()->setTitle(imageTitle(fileName, size));
          }
  
          document()->imageUpdated();
      }
  
      document()->finishedParsing();
  }
      
  // --------
  
  ImageDocument::ImageDocument(Frame* frame, const KURL& url)
      : HTMLDocument(frame, url)
      , m_imageElement(0)
      , m_imageSizeIsKnown(false)
      , m_didShrinkImage(false)
      , m_shouldShrinkImage(shouldShrinkToFit())
  {
      setCompatibilityMode(QuirksMode);
      lockCompatibilityMode();
  }
      
  PassRefPtr<DocumentParser> ImageDocument::createParser()
  {
      return ImageDocumentParser::create(this);
  }
  
  void ImageDocument::createDocumentStructure()
  {
      ExceptionCode ec;
      
      RefPtr<Element> rootElement = Document::createElement(htmlTag, false);
      appendChild(rootElement, ec);
      static_cast<HTMLHtmlElement*>(rootElement.get())->insertedByParser();
  
      if (frame() && frame()->loader())
          frame()->loader()->dispatchDocumentElementAvailable();
      
      RefPtr<Element> body = Document::createElement(bodyTag, false);
      body->setAttribute(styleAttr, "margin: 0px;");
      
      rootElement->appendChild(body, ec);
      
      RefPtr<ImageDocumentElement> imageElement = ImageDocumentElement::create(this);
      
      imageElement->setAttribute(styleAttr, "-webkit-user-select: none");        
      imageElement->setLoadManually(true);
      imageElement->setSrc(url().string());
      
      body->appendChild(imageElement, ec);
      
      if (shouldShrinkToFit()) {
          // Add event listeners
          RefPtr<EventListener> listener = ImageEventListener::create(this);
          if (DOMWindow* domWindow = this->domWindow())
              domWindow->addEventListener("resize", listener, false);
          imageElement->addEventListener("click", listener.release(), false);
      }
  
      m_imageElement = imageElement.get();
  }
  
  float ImageDocument::scale() const
  {
      if (!m_imageElement)
          return 1.0f;
  
      FrameView* view = frame()->view();
      if (!view)
          return 1;
  
      LayoutSize imageSize = m_imageElement->cachedImage()->imageSizeForRenderer(m_imageElement->renderer(), pageZoomFactor(this));
      LayoutSize windowSize = LayoutSize(view->width(), view->height());
      
      float widthScale = (float)windowSize.width() / imageSize.width();
      float heightScale = (float)windowSize.height() / imageSize.height();
  
      return min(widthScale, heightScale);
  }
  
  void ImageDocument::resizeImageToFit()
  {
      if (!m_imageElement)
          return;
  
      LayoutSize imageSize = m_imageElement->cachedImage()->imageSizeForRenderer(m_imageElement->renderer(), pageZoomFactor(this));
  
      float scale = this->scale();
      m_imageElement->setWidth(static_cast<int>(imageSize.width() * scale));
      m_imageElement->setHeight(static_cast<int>(imageSize.height() * scale));
      
      ExceptionCode ec;
      m_imageElement->style()->setProperty(CSSPropertyCursor, "-webkit-zoom-in", false, ec);
  }
  
  void ImageDocument::imageClicked(int x, int y)
  {
      if (!m_imageSizeIsKnown || imageFitsInWindow())
          return;
  
      m_shouldShrinkImage = !m_shouldShrinkImage;
      
      if (m_shouldShrinkImage)
          windowSizeChanged();
      else {
          restoreImageSize();
          
          updateLayout();
          
          float scale = this->scale();
          
          int scrollX = static_cast<int>(x / scale - (float)frame()->view()->width() / 2);
          int scrollY = static_cast<int>(y / scale - (float)frame()->view()->height() / 2);
          
          frame()->view()->setScrollPosition(IntPoint(scrollX, scrollY));
      }
  }
  
  void ImageDocument::imageUpdated()
  {
      ASSERT(m_imageElement);
      
      if (m_imageSizeIsKnown)
          return;
  
      if (m_imageElement->cachedImage()->imageSizeForRenderer(m_imageElement->renderer(), pageZoomFactor(this)).isEmpty())
          return;
      
      m_imageSizeIsKnown = true;
      
      if (shouldShrinkToFit()) {
          // Force resizing of the image
          windowSizeChanged();
      }
  }
  
  void ImageDocument::restoreImageSize()
  {
      if (!m_imageElement || !m_imageSizeIsKnown)
          return;
      
      LayoutSize imageSize = m_imageElement->cachedImage()->imageSizeForRenderer(m_imageElement->renderer(), pageZoomFactor(this));
      m_imageElement->setWidth(imageSize.width());
      m_imageElement->setHeight(imageSize.height());
      
      ExceptionCode ec;
      if (imageFitsInWindow())
          m_imageElement->style()->removeProperty(CSSPropertyCursor, ec);
      else
          m_imageElement->style()->setProperty(CSSPropertyCursor, "-webkit-zoom-out", false, ec);
          
      m_didShrinkImage = false;
  }
  
  bool ImageDocument::imageFitsInWindow() const
  {
      if (!m_imageElement)
          return true;
  
      FrameView* view = frame()->view();
      if (!view)
          return true;
  
      LayoutSize imageSize = m_imageElement->cachedImage()->imageSizeForRenderer(m_imageElement->renderer(), pageZoomFactor(this));
      LayoutSize windowSize = LayoutSize(view->width(), view->height());
      
      return imageSize.width() <= windowSize.width() && imageSize.height() <= windowSize.height();    
  }
  
  void ImageDocument::windowSizeChanged()
  {
      if (!m_imageElement || !m_imageSizeIsKnown)
          return;
  
      bool fitsInWindow = imageFitsInWindow();
      
      // If the image has been explicitly zoomed in, restore the cursor if the image fits
      // and set it to a zoom out cursor if the image doesn't fit
      if (!m_shouldShrinkImage) {
          ExceptionCode ec;
          
          if (fitsInWindow)
              m_imageElement->style()->removeProperty(CSSPropertyCursor, ec);
          else
              m_imageElement->style()->setProperty(CSSPropertyCursor, "-webkit-zoom-out", false, ec);
          return;
      }
      
      if (m_didShrinkImage) {
          // If the window has been resized so that the image fits, restore the image size
          // otherwise update the restored image size.
          if (fitsInWindow)
              restoreImageSize();
          else
              resizeImageToFit();
      } else {
          // If the image isn't resized but needs to be, then resize it.
          if (!fitsInWindow) {
              resizeImageToFit();
              m_didShrinkImage = true;
          }
      }
  }
  
  CachedImage* ImageDocument::cachedImage()
  { 
      if (!m_imageElement)
          createDocumentStructure();
      
      return m_imageElement->cachedImage();
  }
  
  bool ImageDocument::shouldShrinkToFit() const
  {
      return frame()->page()->settings()->shrinksStandaloneImagesToFit() &&
          frame()->page()->mainFrame() == frame();
  }
  
  // --------
  
  void ImageEventListener::handleEvent(ScriptExecutionContext*, Event* event)
  {
      if (event->type() == eventNames().resizeEvent)
          m_doc->windowSizeChanged();
      else if (event->type() == eventNames().clickEvent && event->isMouseEvent()) {
          MouseEvent* mouseEvent = static_cast<MouseEvent*>(event);
          m_doc->imageClicked(mouseEvent->x(), mouseEvent->y());
      }
  }
  
  bool ImageEventListener::operator==(const EventListener& listener)
  {
      if (const ImageEventListener* imageEventListener = ImageEventListener::cast(&listener))
          return m_doc == imageEventListener->m_doc;
      return false;
  }
  
  // --------
  
  ImageDocumentElement::~ImageDocumentElement()
  {
      if (m_imageDocument)
          m_imageDocument->disconnectImageElement();
  }
  
  void ImageDocumentElement::didMoveToNewDocument(Document* oldDocument)
  {
      if (m_imageDocument) {
          m_imageDocument->disconnectImageElement();
          m_imageDocument = 0;
      }
      HTMLImageElement::didMoveToNewDocument(oldDocument);
  }
  
  }
  