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