Bug 1744573: Apply single-level transforms in RemoteAccessibleBase::Bounds r=eeejay,Jamie,emilio

Differential Revision: https://phabricator.services.mozilla.com/D131554

accessible/generic/LocalAccessible.cpp

@@ -670,8 +670,8 @@ nsRect LocalAccessible::ParentRelativeBounds() {
     }
 
     nsIFrame* boundingFrame = FindNearestAccessibleAncestorFrame();
-    nsRect unionRect = nsLayoutUtils::GetAllInFlowRectsUnion(
+    nsRect unionRect =
-        frame, boundingFrame, nsLayoutUtils::RECTS_ACCOUNT_FOR_TRANSFORMS);
+        nsLayoutUtils::GetAllInFlowRectsUnion(frame, boundingFrame);
 
     if (unionRect.IsEmpty()) {
       // If we end up with a 0x0 rect from above (or one with negative
@@ -3377,7 +3377,6 @@ void LocalAccessible::MaybeQueueCacheUpdateForStyleChanges() {
 
   if (nsIFrame* frame = GetFrame()) {
     const ComputedStyle* newStyle = frame->Style();
-    MOZ_ASSERT(newStyle != mOldComputedStyle, "New style matches old style!");
 
     nsAutoCString oldVal, newVal;
     mOldComputedStyle->GetComputedPropertyValue(eCSSProperty_display, oldVal);

accessible/ipc/RemoteAccessibleBase.cpp

@@ -16,6 +16,7 @@
 #include "mozilla/dom/BrowserParent.h"
 #include "mozilla/dom/CanonicalBrowsingContext.h"
 #include "mozilla/dom/DocumentInlines.h"
+#include "mozilla/gfx/Matrix.h"
 #include "mozilla/Unused.h"
 #include "nsAccUtils.h"
 #include "nsTextEquivUtils.h"
@@ -313,13 +314,39 @@ Maybe<nsRect> RemoteAccessibleBase<Derived>::RetrieveCachedBounds() const {
   return Nothing();
 }
 
+template <class Derived>
+bool RemoteAccessibleBase<Derived>::ApplyTransform(nsRect& aBounds) const {
+  // First, attempt to retrieve the transform from the cache.
+  Maybe<const UniquePtr<gfx::Matrix4x4>&> maybeTransform =
+      mCachedFields->GetAttribute<UniquePtr<gfx::Matrix4x4>>(
+          nsGkAtoms::transform);
+  if (!maybeTransform) {
+    return false;
+  }
+  // The transform matrix we cache is meant to operate on rects
+  // within the coordinate space of the frame to which the
+  // transform is applied (self-relative rects). We cache bounds
+  // relative to some ancestor. Remove the relative offset before
+  // transforming. The transform matrix will add it back in.
+  aBounds.MoveTo(0, 0);
+  auto mtxInPixels = gfx::Matrix4x4Typed<CSSPixel, CSSPixel>::FromUnknownMatrix(
+      *(*maybeTransform));
+
+  // Our matrix is in CSS Pixels, so we need our rect to be in CSS
+  // Pixels too. Convert before applying.
+  auto boundsInPixels = CSSRect::FromAppUnits(aBounds);
+  boundsInPixels = mtxInPixels.TransformBounds(boundsInPixels);
+  aBounds = CSSRect::ToAppUnits(boundsInPixels);
+
+  return true;
+}
+
 template <class Derived>
 LayoutDeviceIntRect RemoteAccessibleBase<Derived>::Bounds() const {
   if (mCachedFields) {
     Maybe<nsRect> maybeBounds = RetrieveCachedBounds();
     if (maybeBounds) {
       nsRect bounds = *maybeBounds;
-      LayoutDeviceIntRect devPxBounds;
       dom::CanonicalBrowsingContext* cbc =
           static_cast<dom::BrowserParent*>(mDoc->Manager())
               ->GetBrowsingContext()
@@ -328,7 +355,11 @@ LayoutDeviceIntRect RemoteAccessibleBase<Derived>::Bounds() const {
       nsPresContext* presContext =
           bp->GetOwnerElement()->OwnerDoc()->GetPresContext();
 
+      Unused << ApplyTransform(bounds);
+
+      LayoutDeviceIntRect devPxBounds;
       const Accessible* acc = this;
+
       while (acc) {
         if (LocalAccessible* localAcc =
                 const_cast<Accessible*>(acc)->AsLocal()) {
@@ -349,7 +380,6 @@ LayoutDeviceIntRect RemoteAccessibleBase<Derived>::Bounds() const {
           // by GetFullZoom because LocalAccessible::Bounds already does
           // that.
           devPxBounds.MoveBy(localBounds.X(), localBounds.Y());
-
           break;
         }
 
@@ -360,6 +390,7 @@ LayoutDeviceIntRect RemoteAccessibleBase<Derived>::Bounds() const {
             (remoteAcc == this) ? Nothing() : remoteAcc->RetrieveCachedBounds();
 
         if (maybeRemoteBounds) {
+          nsRect remoteBounds = *maybeRemoteBounds;
           // We need to take into account a non-1 resolution set on the
           // presshell. This happens with async pinch zooming, among other
           // things. We can't reliably query this value in the parent process,
@@ -378,11 +409,10 @@ LayoutDeviceIntRect RemoteAccessibleBase<Derived>::Bounds() const {
             bounds.ScaleRoundOut(res.valueOr(1.0f));
           }
 
-          // Regardless of whether this is a doc, we should offset `bounds`
+          // We should offset `bounds` by the bounds retrieved above.
-          // by the bounds retrieved here. This is how we build screen
+          // This is how we build screen coordinates from relative coordinates.
-          // coordinates from relative coordinates.
-          nsRect remoteBounds = *maybeRemoteBounds;
           bounds.MoveBy(remoteBounds.X(), remoteBounds.Y());
+          Unused << remoteAcc->ApplyTransform(bounds);
         }
 
         acc = acc->Parent();

accessible/ipc/RemoteAccessibleBase.h

@@ -320,6 +320,7 @@ class RemoteAccessibleBase : public Accessible, public HyperTextAccessibleBase {
  protected:
   void SetParent(Derived* aParent);
   Maybe<nsRect> RetrieveCachedBounds() const;
+  bool ApplyTransform(nsRect& aBounds) const;
 
   virtual void ARIAGroupPosition(int32_t* aLevel, int32_t* aSetSize,
                                  int32_t* aPosInSet) const override;

accessible/tests/browser/bounds/browser.ini

@@ -17,3 +17,4 @@ https_first_disabled = true
 skip-if = e10s && os == 'win' # bug 1372296
 [browser_zero_area.js]
 [browser_test_display_contents.js]
+[browser_test_simple_transform.js]

accessible/tests/browser/bounds/browser_test_simple_transform.js

@@ -0,0 +1,110 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+async function finishContentPaint(browser) {
+  await SpecialPowers.spawn(browser, [], () => {
+    return new Promise(function(r) {
+      content.requestAnimationFrame(() => content.setTimeout(r));
+    });
+  });
+}
+
+async function testContentBoundsInIframe(iframeDocAcc, id, browser) {
+  const acc = findAccessibleChildByID(iframeDocAcc, id);
+  const x = {};
+  const y = {};
+  const width = {};
+  const height = {};
+  acc.getBounds(x, y, width, height);
+
+  await invokeContentTask(
+    browser,
+    [id, x.value, y.value, width.value, height.value],
+    (_id, _x, _y, _width, _height) => {
+      const { Layout: LayoutUtils } = ChromeUtils.import(
+        "chrome://mochitests/content/browser/accessible/tests/browser/Layout.jsm"
+      );
+
+      let [
+        expectedX,
+        expectedY,
+        expectedWidth,
+        expectedHeight,
+      ] = LayoutUtils.getBoundsForDOMElm(_id, content.document);
+
+      ok(
+        _x >= expectedX - 5 || _x <= expectedX + 5,
+        "Got " + _x + ", accurate x for " + _id
+      );
+      ok(
+        _y >= expectedY - 5 || _y <= expectedY + 5,
+        "Got " + _y + ", accurate y for " + _id
+      );
+      ok(
+        _width >= expectedWidth - 5 || _width <= expectedWidth + 5,
+        "Got " + _width + ", accurate width for " + _id
+      );
+      ok(
+        _height >= expectedHeight - 5 || _height <= expectedHeight + 5,
+        "Got " + _height + ", accurate height for " + _id
+      );
+    }
+  );
+}
+
+// test basic translation
+addAccessibleTask(
+  `<p id="translate">hello world</p>`,
+  async function(browser, iframeDocAcc, contentDocAcc) {
+    ok(iframeDocAcc, "IFRAME document accessible is present");
+    await testContentBoundsInIframe(iframeDocAcc, "translate", browser);
+
+    await invokeContentTask(browser, [], () => {
+      let p = content.document.getElementById("translate");
+      p.style = "transform: translate(100px, 100px);";
+    });
+
+    await finishContentPaint(browser);
+    await testContentBoundsInIframe(iframeDocAcc, "translate", browser);
+  },
+  { topLevel: true, iframe: true, remoteIframe: true }
+);
+
+// test basic rotation
+addAccessibleTask(
+  `<p id="rotate">hello world</p>`,
+  async function(browser, iframeDocAcc, contentDocAcc) {
+    ok(iframeDocAcc, "IFRAME document accessible is present");
+    await testContentBoundsInIframe(iframeDocAcc, "rotate", browser);
+
+    await invokeContentTask(browser, [], () => {
+      let p = content.document.getElementById("rotate");
+      p.style = "transform: rotate(-40deg);";
+    });
+
+    await finishContentPaint(browser);
+    await testContentBoundsInIframe(iframeDocAcc, "rotate", browser);
+  },
+  { topLevel: true, iframe: true, remoteIframe: true }
+);
+
+// test basic scale
+addAccessibleTask(
+  `<p id="scale">hello world</p>`,
+  async function(browser, iframeDocAcc, contentDocAcc) {
+    ok(iframeDocAcc, "IFRAME document accessible is present");
+    await testContentBoundsInIframe(iframeDocAcc, "scale", browser);
+
+    await invokeContentTask(browser, [], () => {
+      let p = content.document.getElementById("scale");
+      p.style = "transform: scale(2);";
+    });
+
+    await finishContentPaint(browser);
+    await testContentBoundsInIframe(iframeDocAcc, "scale", browser);
+  },
+  { topLevel: true, iframe: true, remoteIframe: true }
+);

layout/base/nsLayoutUtils.cpp

@@ -3680,7 +3680,11 @@ struct BoxToRect : public nsLayoutUtils::BoxCallback {
         nsLayoutUtils::TransformRect(outer, mRelativeTo, r);
       }
     } else {
-      r += outer->GetOffsetTo(mRelativeTo);
+      if (aFrame->PresContext() != mRelativeTo->PresContext()) {
+        r += outer->GetOffsetToCrossDoc(mRelativeTo);
+      } else {
+        r += outer->GetOffsetTo(mRelativeTo);
+      }
     }
     mCallback->AddRect(r);
   }