layout/base/GeometryUtils.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 #include "GeometryUtils.h"
   8
   9 #include "mozilla/PresShell.h"
  10 #include "mozilla/SVGUtils.h"
  11 #include "mozilla/dom/CharacterData.h"
  12 #include "mozilla/dom/DOMPointBinding.h"
  13 #include "mozilla/dom/GeometryUtilsBinding.h"
  14 #include "mozilla/dom/Element.h"
  15 #include "mozilla/dom/Text.h"
  16 #include "mozilla/dom/DocumentInlines.h"
  17 #include "mozilla/dom/DOMPoint.h"
  18 #include "mozilla/dom/DOMQuad.h"
  19 #include "mozilla/dom/DOMRect.h"
  20 #include "mozilla/dom/BrowserChild.h"
  21 #include "nsIFrame.h"
  22 #include "nsContainerFrame.h"
  23 #include "nsContentUtils.h"
  24 #include "nsCSSFrameConstructor.h"
  25 #include "nsLayoutUtils.h"
  26
  27 using namespace mozilla;
  28 using namespace mozilla::dom;
  29
  30 namespace mozilla {
  31
  32 enum GeometryNodeType {
  33   GEOMETRY_NODE_ELEMENT,
  34   GEOMETRY_NODE_TEXT,
  35   GEOMETRY_NODE_DOCUMENT
  36 };
  37
  38 static nsIFrame* GetFrameForNode(nsINode* aNode, GeometryNodeType aType,
  39                                  bool aCreateFramesForSuppressedWhitespace) {
  40   Document* doc = aNode->OwnerDoc();
  41   if (aType == GEOMETRY_NODE_TEXT && aCreateFramesForSuppressedWhitespace) {
  42     if (PresShell* presShell = doc->GetPresShell()) {
  43       presShell->FrameConstructor()->EnsureFrameForTextNodeIsCreatedAfterFlush(
  44           static_cast<CharacterData*>(aNode));
  45     }
  46   }
  47   doc->FlushPendingNotifications(FlushType::Layout);
  48
  49   switch (aType) {
  50     case GEOMETRY_NODE_TEXT:
  51     case GEOMETRY_NODE_ELEMENT:
  52       return aNode->AsContent()->GetPrimaryFrame();
  53     case GEOMETRY_NODE_DOCUMENT: {
  54       PresShell* presShell = doc->GetPresShell();
  55       return presShell ? presShell->GetRootFrame() : nullptr;
  56     }
  57     default:
  58       MOZ_ASSERT(false, "Unknown GeometryNodeType");
  59       return nullptr;
  60   }
  61 }
  62
  63 static nsIFrame* GetFrameForGeometryNode(
  64     const Optional<OwningGeometryNode>& aGeometryNode, nsINode* aDefaultNode,
  65     bool aCreateFramesForSuppressedWhitespace) {
  66   if (!aGeometryNode.WasPassed()) {
  67     return GetFrameForNode(aDefaultNode->OwnerDoc(), GEOMETRY_NODE_DOCUMENT,
  68                            aCreateFramesForSuppressedWhitespace);
  69   }
  70
  71   const OwningGeometryNode& value = aGeometryNode.Value();
  72   if (value.IsElement()) {
  73     return GetFrameForNode(value.GetAsElement(), GEOMETRY_NODE_ELEMENT,
  74                            aCreateFramesForSuppressedWhitespace);
  75   }
  76   if (value.IsDocument()) {
  77     return GetFrameForNode(value.GetAsDocument(), GEOMETRY_NODE_DOCUMENT,
  78                            aCreateFramesForSuppressedWhitespace);
  79   }
  80   return GetFrameForNode(value.GetAsText(), GEOMETRY_NODE_TEXT,
  81                          aCreateFramesForSuppressedWhitespace);
  82 }
  83
  84 static nsIFrame* GetFrameForGeometryNode(const GeometryNode& aGeometryNode) {
  85   // This will create frames for suppressed whitespace nodes.
  86   if (aGeometryNode.IsElement()) {
  87     return GetFrameForNode(&aGeometryNode.GetAsElement(), GEOMETRY_NODE_ELEMENT,
  88                            true);
  89   }
  90   if (aGeometryNode.IsDocument()) {
  91     return GetFrameForNode(&aGeometryNode.GetAsDocument(),
  92                            GEOMETRY_NODE_DOCUMENT, true);
  93   }
  94   return GetFrameForNode(&aGeometryNode.GetAsText(), GEOMETRY_NODE_TEXT, true);
  95 }
  96
  97 static nsIFrame* GetFrameForNode(nsINode* aNode,
  98                                  bool aCreateFramesForSuppressedWhitespace) {
  99   if (aNode->IsElement()) {
 100     return GetFrameForNode(aNode, GEOMETRY_NODE_ELEMENT,
 101                            aCreateFramesForSuppressedWhitespace);
 102   }
 103   if (aNode == aNode->OwnerDoc()) {
 104     return GetFrameForNode(aNode, GEOMETRY_NODE_DOCUMENT,
 105                            aCreateFramesForSuppressedWhitespace);
 106   }
 107   NS_ASSERTION(aNode->IsText(), "Unknown node type");
 108   return GetFrameForNode(aNode, GEOMETRY_NODE_TEXT,
 109                          aCreateFramesForSuppressedWhitespace);
 110 }
 111
 112 static nsIFrame* GetFirstNonAnonymousFrameForGeometryNode(
 113     const Optional<OwningGeometryNode>& aNode, nsINode* aDefaultNode,
 114     bool aCreateFramesForSuppressedWhitespace) {
 115   nsIFrame* f = GetFrameForGeometryNode(aNode, aDefaultNode,
 116                                         aCreateFramesForSuppressedWhitespace);
 117   if (f) {
 118     f = nsLayoutUtils::GetFirstNonAnonymousFrame(f);
 119   }
 120   return f;
 121 }
 122
 123 static nsIFrame* GetFirstNonAnonymousFrameForGeometryNode(
 124     const GeometryNode& aNode) {
 125   // This will create frames for suppressed whitespace nodes.
 126   nsIFrame* f = GetFrameForGeometryNode(aNode);
 127   if (f) {
 128     f = nsLayoutUtils::GetFirstNonAnonymousFrame(f);
 129   }
 130   return f;
 131 }
 132
 133 static nsIFrame* GetFirstNonAnonymousFrameForNode(nsINode* aNode) {
 134   // This will create frames for suppressed whitespace nodes.
 135   nsIFrame* f = GetFrameForNode(aNode, true);
 136   if (f) {
 137     f = nsLayoutUtils::GetFirstNonAnonymousFrame(f);
 138   }
 139   return f;
 140 }
 141
 142 /**
 143  * This can modify aFrame to point to a different frame. This is needed to
 144  * handle SVG, where SVG elements can only compute a rect that's valid with
 145  * respect to the "outer SVG" frame.
 146  */
 147 static nsRect GetBoxRectForFrame(nsIFrame** aFrame, CSSBoxType aType) {
 148   nsRect r;
 149   nsIFrame* f = SVGUtils::GetOuterSVGFrameAndCoveredRegion(*aFrame, &r);
 150   if (f && f != *aFrame) {
 151     // For non-outer SVG frames, the BoxType is ignored.
 152     *aFrame = f;
 153     return r;
 154   }
 155
 156   f = *aFrame;
 157   switch (aType) {
 158     case CSSBoxType::Content:
 159       r = f->GetContentRectRelativeToSelf();
 160       break;
 161     case CSSBoxType::Padding:
 162       r = f->GetPaddingRectRelativeToSelf();
 163       break;
 164     case CSSBoxType::Border:
 165       r = nsRect(nsPoint(0, 0), f->GetSize());
 166       break;
 167     case CSSBoxType::Margin:
 168       r = f->GetMarginRectRelativeToSelf();
 169       break;
 170     default:
 171       MOZ_ASSERT(false, "unknown box type");
 172       return r;
 173   }
 174
 175   return r;
 176 }
 177
 178 class AccumulateQuadCallback : public nsLayoutUtils::BoxCallback {
 179  public:
 180   AccumulateQuadCallback(Document* aParentObject,
 181                          nsTArray<RefPtr<DOMQuad> >& aResult,
 182                          nsIFrame* aRelativeToFrame,
 183                          const nsPoint& aRelativeToBoxTopLeft,
 184                          CSSBoxType aBoxType)
 185       : mParentObject(ToSupports(aParentObject)),
 186         mResult(aResult),
 187         mRelativeToFrame(aRelativeToFrame),
 188         mRelativeToBoxTopLeft(aRelativeToBoxTopLeft),
 189         mBoxType(aBoxType) {
 190     if (mBoxType == CSSBoxType::Margin) {
 191       // Don't include the caption margin when computing margins for a
 192       // table
 193       mIncludeCaptionBoxForTable = false;
 194     }
 195   }
 196
 197   void AddBox(nsIFrame* aFrame) override {
 198     nsIFrame* f = aFrame;
 199     if (mBoxType == CSSBoxType::Margin && f->IsTableFrame()) {
 200       // Margin boxes for table frames should be taken from the table wrapper
 201       // frame, since that has the margin.
 202       f = f->GetParent();
 203     }
 204     nsRect box = GetBoxRectForFrame(&f, mBoxType);
 205     nsPoint appUnits[4] = {box.TopLeft(), box.TopRight(), box.BottomRight(),
 206                            box.BottomLeft()};
 207     CSSPoint points[4];
 208     for (uint32_t i = 0; i < 4; ++i) {
 209       points[i] =
 210           CSSPoint(nsPresContext::AppUnitsToFloatCSSPixels(appUnits[i].x),
 211                    nsPresContext::AppUnitsToFloatCSSPixels(appUnits[i].y));
 212     }
 213     nsLayoutUtils::TransformResult rv = nsLayoutUtils::TransformPoints(
 214         RelativeTo{f}, RelativeTo{mRelativeToFrame}, 4, points);
 215     if (rv == nsLayoutUtils::TRANSFORM_SUCCEEDED) {
 216       CSSPoint delta(
 217           nsPresContext::AppUnitsToFloatCSSPixels(mRelativeToBoxTopLeft.x),
 218           nsPresContext::AppUnitsToFloatCSSPixels(mRelativeToBoxTopLeft.y));
 219       for (uint32_t i = 0; i < 4; ++i) {
 220         points[i] -= delta;
 221       }
 222     } else {
 223       PodArrayZero(points);
 224     }
 225     mResult.AppendElement(new DOMQuad(mParentObject, points));
 226   }
 227
 228   nsISupports* mParentObject;
 229   nsTArray<RefPtr<DOMQuad> >& mResult;
 230   nsIFrame* mRelativeToFrame;
 231   nsPoint mRelativeToBoxTopLeft;
 232   CSSBoxType mBoxType;
 233 };
 234
 235 static nsPresContext* FindTopLevelPresContext(nsPresContext* aPC) {
 236   bool isChrome = aPC->IsChrome();
 237   nsPresContext* pc = aPC;
 238   for (;;) {
 239     nsPresContext* parent = pc->GetParentPresContext();
 240     if (!parent || parent->IsChrome() != isChrome) {
 241       return pc;
 242     }
 243     pc = parent;
 244   }
 245 }
 246
 247 static bool CheckFramesInSameTopLevelBrowsingContext(nsIFrame* aFrame1,
 248                                                      nsIFrame* aFrame2,
 249                                                      CallerType aCallerType) {
 250   nsPresContext* pc1 = aFrame1->PresContext();
 251   nsPresContext* pc2 = aFrame2->PresContext();
 252   if (pc1 == pc2) {
 253     return true;
 254   }
 255   if (aCallerType == CallerType::System) {
 256     return true;
 257   }
 258   if (FindTopLevelPresContext(pc1) == FindTopLevelPresContext(pc2)) {
 259     return true;
 260   }
 261   return false;
 262 }
 263
 264 void GetBoxQuads(nsINode* aNode, const dom::BoxQuadOptions& aOptions,
 265                  nsTArray<RefPtr<DOMQuad> >& aResult, CallerType aCallerType,
 266                  ErrorResult& aRv) {
 267   nsIFrame* frame =
 268       GetFrameForNode(aNode, aOptions.mCreateFramesForSuppressedWhitespace);
 269   if (!frame) {
 270     // No boxes to return
 271     return;
 272   }
 273   AutoWeakFrame weakFrame(frame);
 274   Document* ownerDoc = aNode->OwnerDoc();
 275   nsIFrame* relativeToFrame = GetFirstNonAnonymousFrameForGeometryNode(
 276       aOptions.mRelativeTo, ownerDoc,
 277       aOptions.mCreateFramesForSuppressedWhitespace);
 278   // The first frame might be destroyed now if the above call lead to an
 279   // EnsureFrameForTextNode call.  We need to get the first frame again
 280   // when that happens and re-check it.
 281   if (!weakFrame.IsAlive()) {
 282     frame =
 283         GetFrameForNode(aNode, aOptions.mCreateFramesForSuppressedWhitespace);
 284     if (!frame) {
 285       // No boxes to return
 286       return;
 287     }
 288   }
 289   if (!relativeToFrame) {
 290     // XXXbz There's no spec for this.
 291     return aRv.ThrowNotFoundError("No box to get quads relative to");
 292   }
 293   if (!CheckFramesInSameTopLevelBrowsingContext(frame, relativeToFrame,
 294                                                 aCallerType)) {
 295     aRv.ThrowNotFoundError(
 296         "Can't get quads relative to a box in a different toplevel browsing "
 297         "context");
 298     return;
 299   }
 300   // GetBoxRectForFrame can modify relativeToFrame so call it first.
 301   nsPoint relativeToTopLeft =
 302       GetBoxRectForFrame(&relativeToFrame, CSSBoxType::Border).TopLeft();
 303   AccumulateQuadCallback callback(ownerDoc, aResult, relativeToFrame,
 304                                   relativeToTopLeft, aOptions.mBox);
 305
 306   // Bug 1624653: Refactor this to get boxes in layer pixels, which we will
 307   // then convert into CSS units.
 308   nsLayoutUtils::GetAllInFlowBoxes(frame, &callback);
 309 }
 310
 311 void GetBoxQuadsFromWindowOrigin(nsINode* aNode,
 312                                  const dom::BoxQuadOptions& aOptions,
 313                                  nsTArray<RefPtr<DOMQuad> >& aResult,
 314                                  ErrorResult& aRv) {
 315   // We want the quads relative to the window. To do this, we ignore the
 316   // provided aOptions.mRelativeTo and instead use the document node of
 317   // the top-most in-process document. Later, we'll check if there is a
 318   // browserChild associated with that document, and if so, transform the
 319   // calculated quads with the browserChild's to-parent matrix, which
 320   // will get us to top-level coordinates.
 321   if (aOptions.mRelativeTo.WasPassed()) {
 322     return aRv.ThrowNotSupportedError(
 323         "Can't request quads in window origin space relative to another "
 324         "node.");
 325   }
 326
 327   // We're going to call GetBoxQuads with our parameters, but we supply
 328   // a new BoxQuadOptions object that uses the top in-process document
 329   // as the relativeTo target.
 330   BoxQuadOptions bqo(aOptions);
 331
 332   RefPtr<Document> topInProcessDoc =
 333       nsContentUtils::GetInProcessSubtreeRootDocument(aNode->OwnerDoc());
 334
 335   OwningGeometryNode ogn;
 336   ogn.SetAsDocument() = topInProcessDoc;
 337   bqo.mRelativeTo.Construct(ogn);
 338
 339   // Bug 1624653: Refactor this to get boxes in layer pixels, which we can
 340   // transform directly with the GetChildToParentConversionMatrix below,
 341   // and convert to CSS units as a final step.
 342   GetBoxQuads(aNode, bqo, aResult, CallerType::System, aRv);
 343   if (aRv.Failed()) {
 344     return;
 345   }
 346
 347   // Now we have aResult filled with DOMQuads with values relative to the
 348   // top in-process document. See if topInProcessDoc is associated with a
 349   // BrowserChild, and if it is, get its transformation matrix and use that
 350   // to transform the DOMQuads in place to make them relative to the window
 351   // origin.
 352   nsIDocShell* docShell = topInProcessDoc->GetDocShell();
 353   if (!docShell) {
 354     return aRv.ThrowInvalidStateError(
 355         "Returning untranslated quads because top in process document has "
 356         "no docshell.");
 357   }
 358
 359   BrowserChild* browserChild = BrowserChild::GetFrom(docShell);
 360   if (!browserChild) {
 361     return;
 362   }
 363
 364   nsPresContext* presContext = docShell->GetPresContext();
 365   if (!presContext) {
 366     return;
 367   }
 368   int32_t appUnitsPerDevPixel = presContext->AppUnitsPerDevPixel();
 369
 370   LayoutDeviceToLayoutDeviceMatrix4x4 matrix =
 371       browserChild->GetChildToParentConversionMatrix();
 372
 373   // For each DOMQuad in aResult, change the css units into layer pixels,
 374   // then transform them by matrix, then change them back into css units
 375   // and overwrite the original points.
 376   LayoutDeviceToCSSScale ld2cScale((float)appUnitsPerDevPixel /
 377                                    (float)AppUnitsPerCSSPixel());
 378   CSSToLayoutDeviceScale c2ldScale = ld2cScale.Inverse();
 379
 380   for (auto& quad : aResult) {
 381     for (uint32_t i = 0; i < 4; i++) {
 382       DOMPoint* p = quad->Point(i);
 383       CSSPoint cp(p->X(), p->Y());
 384
 385       LayoutDevicePoint windowLdp = matrix.TransformPoint(cp * c2ldScale);
 386
 387       CSSPoint windowCp = windowLdp * ld2cScale;
 388       p->SetX(windowCp.x);
 389       p->SetY(windowCp.y);
 390     }
 391   }
 392 }
 393
 394 static void TransformPoints(nsINode* aTo, const GeometryNode& aFrom,
 395                             uint32_t aPointCount, CSSPoint* aPoints,
 396                             const ConvertCoordinateOptions& aOptions,
 397                             CallerType aCallerType, ErrorResult& aRv) {
 398   nsIFrame* fromFrame = GetFirstNonAnonymousFrameForGeometryNode(aFrom);
 399   AutoWeakFrame weakFrame(fromFrame);
 400   nsIFrame* toFrame = GetFirstNonAnonymousFrameForNode(aTo);
 401   // The first frame might be destroyed now if the above call lead to an
 402   // EnsureFrameForTextNode call.  We need to get the first frame again
 403   // when that happens.
 404   if (fromFrame && !weakFrame.IsAlive()) {
 405     fromFrame = GetFirstNonAnonymousFrameForGeometryNode(aFrom);
 406   }
 407   if (!fromFrame || !toFrame) {
 408     aRv.ThrowNotFoundError(
 409         "Can't transform coordinates between nonexistent boxes");
 410     return;
 411   }
 412   if (!CheckFramesInSameTopLevelBrowsingContext(fromFrame, toFrame,
 413                                                 aCallerType)) {
 414     aRv.ThrowNotFoundError(
 415         "Can't transform coordinates between boxes in different toplevel "
 416         "browsing contexts");
 417     return;
 418   }
 419
 420   nsPoint fromOffset =
 421       GetBoxRectForFrame(&fromFrame, aOptions.mFromBox).TopLeft();
 422   nsPoint toOffset = GetBoxRectForFrame(&toFrame, aOptions.mToBox).TopLeft();
 423   CSSPoint fromOffsetGfx(nsPresContext::AppUnitsToFloatCSSPixels(fromOffset.x),
 424                          nsPresContext::AppUnitsToFloatCSSPixels(fromOffset.y));
 425   for (uint32_t i = 0; i < aPointCount; ++i) {
 426     aPoints[i] += fromOffsetGfx;
 427   }
 428   nsLayoutUtils::TransformResult rv = nsLayoutUtils::TransformPoints(
 429       RelativeTo{fromFrame}, RelativeTo{toFrame}, aPointCount, aPoints);
 430   if (rv == nsLayoutUtils::TRANSFORM_SUCCEEDED) {
 431     CSSPoint toOffsetGfx(nsPresContext::AppUnitsToFloatCSSPixels(toOffset.x),
 432                          nsPresContext::AppUnitsToFloatCSSPixels(toOffset.y));
 433     for (uint32_t i = 0; i < aPointCount; ++i) {
 434       aPoints[i] -= toOffsetGfx;
 435     }
 436   } else {
 437     PodZero(aPoints, aPointCount);
 438   }
 439 }
 440
 441 already_AddRefed<DOMQuad> ConvertQuadFromNode(
 442     nsINode* aTo, dom::DOMQuad& aQuad, const GeometryNode& aFrom,
 443     const dom::ConvertCoordinateOptions& aOptions, CallerType aCallerType,
 444     ErrorResult& aRv) {
 445   CSSPoint points[4];
 446   for (uint32_t i = 0; i < 4; ++i) {
 447     DOMPoint* p = aQuad.Point(i);
 448     if (p->W() != 1.0 || p->Z() != 0.0) {
 449       aRv.ThrowInvalidStateError("Point is not 2d");
 450       return nullptr;
 451     }
 452     points[i] = CSSPoint(p->X(), p->Y());
 453   }
 454   TransformPoints(aTo, aFrom, 4, points, aOptions, aCallerType, aRv);
 455   if (aRv.Failed()) {
 456     return nullptr;
 457   }
 458   RefPtr<DOMQuad> result = new DOMQuad(aTo->GetParentObject().mObject, points);
 459   return result.forget();
 460 }
 461
 462 already_AddRefed<DOMQuad> ConvertRectFromNode(
 463     nsINode* aTo, dom::DOMRectReadOnly& aRect, const GeometryNode& aFrom,
 464     const dom::ConvertCoordinateOptions& aOptions, CallerType aCallerType,
 465     ErrorResult& aRv) {
 466   CSSPoint points[4];
 467   double x = aRect.X(), y = aRect.Y(), w = aRect.Width(), h = aRect.Height();
 468   points[0] = CSSPoint(x, y);
 469   points[1] = CSSPoint(x + w, y);
 470   points[2] = CSSPoint(x + w, y + h);
 471   points[3] = CSSPoint(x, y + h);
 472   TransformPoints(aTo, aFrom, 4, points, aOptions, aCallerType, aRv);
 473   if (aRv.Failed()) {
 474     return nullptr;
 475   }
 476   RefPtr<DOMQuad> result = new DOMQuad(aTo->GetParentObject().mObject, points);
 477   return result.forget();
 478 }
 479
 480 already_AddRefed<DOMPoint> ConvertPointFromNode(
 481     nsINode* aTo, const dom::DOMPointInit& aPoint, const GeometryNode& aFrom,
 482     const dom::ConvertCoordinateOptions& aOptions, CallerType aCallerType,
 483     ErrorResult& aRv) {
 484   if (aPoint.mW != 1.0 || aPoint.mZ != 0.0) {
 485     aRv.ThrowInvalidStateError("Point is not 2d");
 486     return nullptr;
 487   }
 488   CSSPoint point(aPoint.mX, aPoint.mY);
 489   TransformPoints(aTo, aFrom, 1, &point, aOptions, aCallerType, aRv);
 490   if (aRv.Failed()) {
 491     return nullptr;
 492   }
 493   RefPtr<DOMPoint> result =
 494       new DOMPoint(aTo->GetParentObject().mObject, point.x, point.y);
 495   return result.forget();
 496 }
 497
 498 }  // namespace mozilla