image/src/SVGDocumentWrapper.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 /* This class wraps an SVG document, for use by VectorImage objects. */
   7
   8 #ifndef mozilla_imagelib_SVGDocumentWrapper_h_
   9 #define mozilla_imagelib_SVGDocumentWrapper_h_
  10
  11 #include "mozilla/Attributes.h"
  12
  13 #include "nsCOMPtr.h"
  14 #include "nsIStreamListener.h"
  15 #include "nsIObserver.h"
  16 #include "nsIContentViewer.h"
  17 #include "nsWeakReference.h"
  18
  19 class nsIAtom;
  20 class nsIPresShell;
  21 class nsIRequest;
  22 class nsILoadGroup;
  23 class nsIFrame;
  24 struct nsIntSize;
  25
  26 #define OBSERVER_SVC_CID "@mozilla.org/observer-service;1"
  27
  28 // undef the GetCurrentTime macro defined in WinBase.h from the MS Platform SDK
  29 #undef GetCurrentTime
  30
  31 namespace mozilla {
  32 namespace dom {
  33 class SVGSVGElement;
  34 }
  35
  36 namespace image {
  37
  38 class SVGDocumentWrapper MOZ_FINAL : public nsIStreamListener,
  39                                      public nsIObserver,
  40                                      nsSupportsWeakReference
  41 {
  42 public:
  43   SVGDocumentWrapper();
  44   ~SVGDocumentWrapper();
  45
  46   NS_DECL_ISUPPORTS
  47   NS_DECL_NSISTREAMLISTENER
  48   NS_DECL_NSIREQUESTOBSERVER
  49   NS_DECL_NSIOBSERVER
  50
  51   enum Dimension {
  52     eWidth,
  53     eHeight
  54   };
  55
  56   /**
  57    * Looks up the value of the wrapped SVG document's |width| or |height|
  58    * attribute in CSS pixels, and returns it by reference.  If the document has
  59    * a percent value for the queried attribute, then this method fails
  60    * (returns false).
  61    *
  62    * @param aDimension    Indicates whether the width or height is desired.
  63    * @param[out] aResult  If this method succeeds, then this outparam will be
  64                           populated with the width or height in CSS pixels.
  65    * @return false to indicate failure, if the queried attribute has a
  66    *         percent value.  Otherwise, true.
  67    *
  68    */
  69   bool      GetWidthOrHeight(Dimension aDimension, int32_t& aResult);
  70
  71   /**
  72    * Returns the wrapped document, or nullptr on failure. (No AddRef.)
  73    */
  74   nsIDocument* GetDocument();
  75
  76   /**
  77    * Returns the root <svg> element for the wrapped document, or nullptr on
  78    * failure.
  79    */
  80   mozilla::dom::SVGSVGElement* GetRootSVGElem();
  81
  82   /**
  83    * Returns the root nsIFrame* for the wrapped document, or nullptr on failure.
  84    *
  85    * @return the root nsIFrame* for the wrapped document, or nullptr on failure.
  86    */
  87   nsIFrame* GetRootLayoutFrame();
  88
  89   /**
  90    * Returns (by reference) the nsIPresShell for the wrapped document.
  91    *
  92    * @param[out] aPresShell On success, this will be populated with a pointer
  93    *                        to the wrapped document's nsIPresShell.
  94    *
  95    * @return NS_OK on success, or an error code on failure.
  96    */
  97   inline nsresult  GetPresShell(nsIPresShell** aPresShell)
  98     { return mViewer->GetPresShell(aPresShell); }
  99
 100   /**
 101    * Modifier to update the viewport dimensions of the wrapped document. This
 102    * method performs a synchronous "Flush_Layout" on the wrapped document,
 103    * since a viewport-change affects layout.
 104    *
 105    * @param aViewportSize The new viewport dimensions.
 106    */
 107   void UpdateViewportBounds(const nsIntSize& aViewportSize);
 108
 109   /**
 110    * If an SVG image's helper document has a pending notification for an
 111    * override on the root node's "preserveAspectRatio" attribute, then this
 112    * method will flush that notification so that the image can paint correctly.
 113    * (First, though, it sets the mIgnoreInvalidation flag so that we won't
 114    * notify the image's observers and trigger unwanted repaint-requests.)
 115    */
 116   void FlushImageTransformInvalidation();
 117
 118   /**
 119    * Returns a bool indicating whether the document has any SMIL animations.
 120    *
 121    * @return true if the document has any SMIL animations. Else, false.
 122    */
 123   bool      IsAnimated();
 124
 125   /**
 126    * Indicates whether we should currently ignore rendering invalidations sent
 127    * from the wrapped SVG doc.
 128    *
 129    * @return true if we should ignore invalidations sent from this SVG doc.
 130    */
 131   bool ShouldIgnoreInvalidation() { return mIgnoreInvalidation; }
 132
 133   /**
 134    * Methods to control animation.
 135    */
 136   void StartAnimation();
 137   void StopAnimation();
 138   void ResetAnimation();
 139   float GetCurrentTime();
 140   void SetCurrentTime(float aTime);
 141
 142   /**
 143    * Force a layout flush of the underlying SVG document.
 144    */
 145   void FlushLayout();
 146
 147 private:
 148   nsresult SetupViewer(nsIRequest *aRequest,
 149                        nsIContentViewer** aViewer,
 150                        nsILoadGroup** aLoadGroup);
 151   void     DestroyViewer();
 152   void     RegisterForXPCOMShutdown();
 153   void     UnregisterForXPCOMShutdown();
 154
 155   nsCOMPtr<nsIContentViewer>  mViewer;
 156   nsCOMPtr<nsILoadGroup>      mLoadGroup;
 157   nsCOMPtr<nsIStreamListener> mListener;
 158   bool                        mIgnoreInvalidation;
 159   bool                        mRegisteredForXPCOMShutdown;
 160 };
 161
 162 } // namespace image
 163 } // namespace mozilla
 164
 165 #endif // mozilla_imagelib_SVGDocumentWrapper_h_