layout/svg/SVGViewportFrame.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 // Main header first:
   8 #include "SVGViewportFrame.h"
   9
  10 // Keep others in (case-insensitive) order:
  11 #include "gfx2DGlue.h"
  12 #include "gfxContext.h"
  13 #include "mozilla/ISVGDisplayableFrame.h"
  14 #include "mozilla/SVGContainerFrame.h"
  15 #include "mozilla/SVGUtils.h"
  16 #include "mozilla/dom/SVGViewportElement.h"
  17 #include "nsLayoutUtils.h"
  18
  19 using namespace mozilla::dom;
  20 using namespace mozilla::gfx;
  21 using namespace mozilla::image;
  22
  23 namespace mozilla {
  24
  25 //----------------------------------------------------------------------
  26 // ISVGDisplayableFrame methods
  27
  28 void SVGViewportFrame::PaintSVG(gfxContext& aContext,
  29                                 const gfxMatrix& aTransform,
  30                                 imgDrawingParams& aImgParams) {
  31   NS_ASSERTION(HasAnyStateBits(NS_FRAME_IS_NONDISPLAY),
  32                "Only painting of non-display SVG should take this code path");
  33
  34   gfxClipAutoSaveRestore autoSaveClip(&aContext);
  35
  36   if (StyleDisplay()->IsScrollableOverflow()) {
  37     float x, y, width, height;
  38     static_cast<SVGViewportElement*>(GetContent())
  39         ->GetAnimatedLengthValues(&x, &y, &width, &height, nullptr);
  40
  41     if (width <= 0 || height <= 0) {
  42       return;
  43     }
  44
  45     gfxRect clipRect = SVGUtils::GetClipRectForFrame(this, x, y, width, height);
  46     autoSaveClip.TransformedClip(aTransform, clipRect);
  47   }
  48
  49   SVGDisplayContainerFrame::PaintSVG(aContext, aTransform, aImgParams);
  50 }
  51
  52 void SVGViewportFrame::ReflowSVG() {
  53   // mRect must be set before FinishAndStoreOverflow is called in order
  54   // for our overflow areas to be clipped correctly.
  55   float x, y, width, height;
  56   static_cast<SVGViewportElement*>(GetContent())
  57       ->GetAnimatedLengthValues(&x, &y, &width, &height, nullptr);
  58   mRect = nsLayoutUtils::RoundGfxRectToAppRect(gfxRect(x, y, width, height),
  59                                                AppUnitsPerCSSPixel());
  60
  61   // If we have a filter, we need to invalidate ourselves because filter
  62   // output can change even if none of our descendants need repainting.
  63   if (StyleEffects()->HasFilters()) {
  64     InvalidateFrame();
  65   }
  66
  67   SVGDisplayContainerFrame::ReflowSVG();
  68 }
  69
  70 void SVGViewportFrame::NotifySVGChanged(uint32_t aFlags) {
  71   MOZ_ASSERT(aFlags & (TRANSFORM_CHANGED | COORD_CONTEXT_CHANGED),
  72              "Invalidation logic may need adjusting");
  73
  74   if (aFlags & COORD_CONTEXT_CHANGED) {
  75     SVGViewportElement* svg = static_cast<SVGViewportElement*>(GetContent());
  76
  77     bool xOrYIsPercentage =
  78         svg->mLengthAttributes[SVGViewportElement::ATTR_X].IsPercentage() ||
  79         svg->mLengthAttributes[SVGViewportElement::ATTR_Y].IsPercentage();
  80     bool widthOrHeightIsPercentage =
  81         svg->mLengthAttributes[SVGViewportElement::ATTR_WIDTH].IsPercentage() ||
  82         svg->mLengthAttributes[SVGViewportElement::ATTR_HEIGHT].IsPercentage();
  83
  84     if (xOrYIsPercentage || widthOrHeightIsPercentage) {
  85       // Ancestor changes can't affect how we render from the perspective of
  86       // any rendering observers that we may have, so we don't need to
  87       // invalidate them. We also don't need to invalidate ourself, since our
  88       // changed ancestor will have invalidated its entire area, which includes
  89       // our area.
  90       // For perf reasons we call this before calling NotifySVGChanged() below.
  91       SVGUtils::ScheduleReflowSVG(this);
  92     }
  93
  94     // Coordinate context changes affect mCanvasTM if we have a
  95     // percentage 'x' or 'y', or if we have a percentage 'width' or 'height' AND
  96     // a 'viewBox'.
  97
  98     if (!(aFlags & TRANSFORM_CHANGED) &&
  99         (xOrYIsPercentage ||
 100          (widthOrHeightIsPercentage && svg->HasViewBox()))) {
 101       aFlags |= TRANSFORM_CHANGED;
 102     }
 103
 104     if (svg->HasViewBox() || !widthOrHeightIsPercentage) {
 105       // Remove COORD_CONTEXT_CHANGED, since we establish the coordinate
 106       // context for our descendants and this notification won't change its
 107       // dimensions:
 108       aFlags &= ~COORD_CONTEXT_CHANGED;
 109
 110       if (!aFlags) {
 111         return;  // No notification flags left
 112       }
 113     }
 114   }
 115
 116   SVGDisplayContainerFrame::NotifySVGChanged(aFlags);
 117 }
 118
 119 SVGBBox SVGViewportFrame::GetBBoxContribution(const Matrix& aToBBoxUserspace,
 120                                               uint32_t aFlags) {
 121   // XXXjwatt It seems like authors would want the result to be clipped by the
 122   // viewport we establish if IsScrollableOverflow() is true.  We should
 123   // consider doing that.  See bug 1350755.
 124
 125   SVGBBox bbox;
 126
 127   if (aFlags & SVGUtils::eForGetClientRects) {
 128     // XXXjwatt For consistency with the old code this code includes the
 129     // viewport we establish in the result, but only includes the bounds of our
 130     // descendants if they are not clipped to that viewport.  However, this is
 131     // both inconsistent with Chrome and with the specs.  See bug 1350755.
 132     // Ideally getClientRects/getBoundingClientRect should be consistent with
 133     // getBBox.
 134     float x, y, w, h;
 135     static_cast<SVGViewportElement*>(GetContent())
 136         ->GetAnimatedLengthValues(&x, &y, &w, &h, nullptr);
 137     if (w < 0.0f) w = 0.0f;
 138     if (h < 0.0f) h = 0.0f;
 139     Rect viewport(x, y, w, h);
 140     bbox = aToBBoxUserspace.TransformBounds(viewport);
 141     if (StyleDisplay()->IsScrollableOverflow()) {
 142       return bbox;
 143     }
 144     // Else we're not clipping to our viewport so we fall through and include
 145     // the bounds of our children.
 146   }
 147
 148   SVGBBox descendantsBbox =
 149       SVGDisplayContainerFrame::GetBBoxContribution(aToBBoxUserspace, aFlags);
 150
 151   bbox.UnionEdges(descendantsBbox);
 152
 153   return bbox;
 154 }
 155
 156 nsresult SVGViewportFrame::AttributeChanged(int32_t aNameSpaceID,
 157                                             nsAtom* aAttribute,
 158                                             int32_t aModType) {
 159   if (aNameSpaceID == kNameSpaceID_None &&
 160       !HasAnyStateBits(NS_FRAME_IS_NONDISPLAY)) {
 161     SVGViewportElement* content =
 162         static_cast<SVGViewportElement*>(GetContent());
 163
 164     if (aAttribute == nsGkAtoms::width || aAttribute == nsGkAtoms::height) {
 165       nsLayoutUtils::PostRestyleEvent(
 166           mContent->AsElement(), RestyleHint{0},
 167           nsChangeHint_InvalidateRenderingObservers);
 168       SVGUtils::ScheduleReflowSVG(this);
 169
 170       if (content->HasViewBoxOrSyntheticViewBox()) {
 171         // make sure our cached transform matrix gets (lazily) updated
 172         mCanvasTM = nullptr;
 173         content->ChildrenOnlyTransformChanged();
 174         SVGUtils::NotifyChildrenOfSVGChange(this, TRANSFORM_CHANGED);
 175       } else {
 176         uint32_t flags = COORD_CONTEXT_CHANGED;
 177         if (mCanvasTM && mCanvasTM->IsSingular()) {
 178           mCanvasTM = nullptr;
 179           flags |= TRANSFORM_CHANGED;
 180         }
 181         SVGUtils::NotifyChildrenOfSVGChange(this, flags);
 182       }
 183
 184     } else if (aAttribute == nsGkAtoms::transform ||
 185                aAttribute == nsGkAtoms::preserveAspectRatio ||
 186                aAttribute == nsGkAtoms::viewBox || aAttribute == nsGkAtoms::x ||
 187                aAttribute == nsGkAtoms::y) {
 188       // make sure our cached transform matrix gets (lazily) updated
 189       mCanvasTM = nullptr;
 190
 191       SVGUtils::NotifyChildrenOfSVGChange(
 192           this, aAttribute == nsGkAtoms::viewBox
 193                     ? TRANSFORM_CHANGED | COORD_CONTEXT_CHANGED
 194                     : TRANSFORM_CHANGED);
 195
 196       // We don't invalidate for transform changes (the layers code does that).
 197       // Also note that SVGTransformableElement::GetAttributeChangeHint will
 198       // return nsChangeHint_UpdateOverflow for "transform" attribute changes
 199       // and cause DoApplyRenderingChangeToTree to make the SchedulePaint call.
 200
 201       if (aAttribute == nsGkAtoms::x || aAttribute == nsGkAtoms::y) {
 202         nsLayoutUtils::PostRestyleEvent(
 203             mContent->AsElement(), RestyleHint{0},
 204             nsChangeHint_InvalidateRenderingObservers);
 205         SVGUtils::ScheduleReflowSVG(this);
 206       } else if (aAttribute == nsGkAtoms::viewBox ||
 207                  (aAttribute == nsGkAtoms::preserveAspectRatio &&
 208                   content->HasViewBoxOrSyntheticViewBox())) {
 209         content->ChildrenOnlyTransformChanged();
 210         // SchedulePaint sets a global state flag so we only need to call it
 211         // once (on ourself is fine), not once on each child (despite bug
 212         // 828240).
 213         SchedulePaint();
 214       }
 215     }
 216   }
 217
 218   return NS_OK;
 219 }
 220
 221 nsIFrame* SVGViewportFrame::GetFrameForPoint(const gfxPoint& aPoint) {
 222   MOZ_ASSERT_UNREACHABLE("A clipPath cannot contain svg or symbol elements");
 223   return nullptr;
 224 }
 225
 226 //----------------------------------------------------------------------
 227 // ISVGSVGFrame methods:
 228
 229 void SVGViewportFrame::NotifyViewportOrTransformChanged(uint32_t aFlags) {
 230   // The dimensions of inner-<svg> frames are purely defined by their "width"
 231   // and "height" attributes, and transform changes can only occur as a result
 232   // of changes to their "width", "height", "viewBox" or "preserveAspectRatio"
 233   // attributes. Changes to all of these attributes are handled in
 234   // AttributeChanged(), so we should never be called.
 235   NS_ERROR("Not called for SVGViewportFrame");
 236 }
 237
 238 //----------------------------------------------------------------------
 239 // SVGContainerFrame methods:
 240
 241 bool SVGViewportFrame::HasChildrenOnlyTransform(gfx::Matrix* aTransform) const {
 242   SVGViewportElement* content = static_cast<SVGViewportElement*>(GetContent());
 243
 244   if (content->HasViewBoxOrSyntheticViewBox()) {
 245     // XXX Maybe return false if the transform is the identity transform?
 246     if (aTransform) {
 247       *aTransform = content->GetViewBoxTransform();
 248     }
 249     return true;
 250   }
 251   return false;
 252 }
 253
 254 }  // namespace mozilla