Bug 1733509 - Use TryInferEnclosingResolution for event retargeting. r=botond

Differential Revision: https://phabricator.services.mozilla.com/D205378

gfx/layers/LayersTypes.cpp

@@ -91,5 +91,17 @@ GpuProcessQueryId GpuProcessQueryId::GetNext() {
   return GpuProcessQueryId{++sCounter};
 }
 
+std::ostream& operator<<(std::ostream& os, ScrollDirection aDirection) {
+  switch (aDirection) {
+    case ScrollDirection::eHorizontal:
+      os << "horizontal";
+      break;
+    case ScrollDirection::eVertical:
+      os << "vertical";
+      break;
+  }
+  return os;
+}
+
 }  // namespace layers
 }  // namespace mozilla

gfx/layers/LayersTypes.h

@@ -463,6 +463,8 @@ MOZ_DEFINE_ENUM_CLASS_WITH_BASE(ScrollDirection, uint8_t, (
   eHorizontal
 ));
 
+std::ostream& operator<<(std::ostream& os, ScrollDirection aDirection);
+
 using ScrollDirections = EnumSet<ScrollDirection, uint8_t>;
 
 constexpr ScrollDirections EitherScrollDirection(ScrollDirection::eVertical,ScrollDirection::eHorizontal);

layout/base/PositionedEventTargeting.cpp

@@ -6,6 +6,7 @@
 
 #include "PositionedEventTargeting.h"
 
+#include "Units.h"
 #include "mozilla/EventListenerManager.h"
 #include "mozilla/MouseEvents.h"
 #include "mozilla/Preferences.h"
@@ -13,18 +14,23 @@
 #include "mozilla/StaticPrefs_dom.h"
 #include "mozilla/StaticPrefs_ui.h"
 #include "mozilla/ToString.h"
+#include "mozilla/ViewportUtils.h"
 #include "mozilla/dom/MouseEventBinding.h"
+#include "mozilla/gfx/Matrix.h"
+#include "mozilla/layers/LayersTypes.h"
 #include "nsContainerFrame.h"
+#include "nsCoord.h"
 #include "nsFrameList.h"  // for DEBUG_FRAME_DUMP
 #include "nsHTMLParts.h"
 #include "nsLayoutUtils.h"
 #include "nsGkAtoms.h"
 #include "nsFontMetrics.h"
+#include "nsIContentInlines.h"
+#include "nsPresContext.h"
 #include "nsPrintfCString.h"
 #include "mozilla/dom/Element.h"
 #include "nsRegion.h"
 #include "nsDeviceContext.h"
-#include "nsIContentInlines.h"
 #include "nsIFrame.h"
 #include <algorithm>
 
@@ -276,15 +282,40 @@ static nsIContent* GetClickableAncestor(
   return nullptr;
 }
 
-static nscoord AppUnitsFromMM(RelativeTo aFrame, uint32_t aMM) {
-  nsPresContext* pc = aFrame.mFrame->PresContext();
-  float result = float(aMM) * (pc->DeviceContext()->AppUnitsPerPhysicalInch() /
-                               MM_PER_INCH_FLOAT);
-  if (aFrame.mViewportType == ViewportType::Layout) {
-    PresShell* presShell = pc->PresShell();
-    result = result / presShell->GetResolution();
+static Scale2D AppUnitsToMMScale(RelativeTo aFrame) {
+  nsPresContext* presContext = aFrame.mFrame->PresContext();
+
+  const int32_t appUnitsPerInch =
+      presContext->DeviceContext()->AppUnitsPerPhysicalInch();
+  const float appUnits =
+      static_cast<float>(appUnitsPerInch) / MM_PER_INCH_FLOAT;
+
+  // Visual coordinates are only used for quantities relative to the
+  // cross-process root content document's root frame. There should
+  // not be an enclosing resolution or transform scale above that.
+  if (aFrame.mViewportType != ViewportType::Layout) {
+    const nscoord scale = NSToCoordRound(appUnits);
+    return Scale2D{static_cast<float>(scale), static_cast<float>(scale)};
   }
-  return NSToCoordRound(result);
+
+  Scale2D localResolution{1.0f, 1.0f};
+  Scale2D enclosingResolution{1.0f, 1.0f};
+
+  if (auto* pc = presContext->GetInProcessRootContentDocumentPresContext()) {
+    PresShell* presShell = pc->PresShell();
+    localResolution = {presShell->GetResolution(), presShell->GetResolution()};
+    enclosingResolution = ViewportUtils::TryInferEnclosingResolution(presShell);
+  }
+
+  const gfx::MatrixScales parentScale =
+      nsLayoutUtils::GetTransformToAncestorScale(aFrame.mFrame);
+  const Scale2D resolution =
+      localResolution * parentScale * enclosingResolution;
+
+  const nscoord scaleX = NSToCoordRound(appUnits / resolution.xScale);
+  const nscoord scaleY = NSToCoordRound(appUnits / resolution.yScale);
+
+  return {static_cast<float>(scaleX), static_cast<float>(scaleY)};
 }
 
 /**
@@ -303,10 +334,11 @@ static nsRect GetTargetRect(RelativeTo aRootFrame,
                             const nsPoint& aPointRelativeToRootFrame,
                             const nsIFrame* aRestrictToDescendants,
                             const EventRadiusPrefs& aPrefs, uint32_t aFlags) {
-  nsMargin m(AppUnitsFromMM(aRootFrame, aPrefs.mRadiusTopmm),
-             AppUnitsFromMM(aRootFrame, aPrefs.mRadiusRightmm),
-             AppUnitsFromMM(aRootFrame, aPrefs.mRadiusBottommm),
-             AppUnitsFromMM(aRootFrame, aPrefs.mRadiusLeftmm));
+  const Scale2D scale = AppUnitsToMMScale(aRootFrame);
+  nsMargin m(aPrefs.mRadiusTopmm * scale.yScale,
+             aPrefs.mRadiusRightmm * scale.xScale,
+             aPrefs.mRadiusBottommm * scale.yScale,
+             aPrefs.mRadiusLeftmm * scale.xScale);
   nsRect r(aPointRelativeToRootFrame, nsSize(0, 0));
   r.Inflate(m);
   if (!(aFlags & INPUT_IGNORE_ROOT_SCROLL_FRAME)) {

layout/base/ViewportUtils.cpp

@@ -260,6 +260,9 @@ const nsIFrame* ViewportUtils::IsZoomedContentRoot(const nsIFrame* aFrame) {
 }
 
 Scale2D ViewportUtils::TryInferEnclosingResolution(PresShell* aShell) {
+  if (!XRE_IsContentProcess()) {
+    return {1.0f, 1.0f};
+  }
   MOZ_ASSERT(aShell && aShell->GetPresContext());
   MOZ_ASSERT(!aShell->GetPresContext()->GetParentPresContext(),
              "TryInferEnclosingResolution can only be called for a root pres "

layout/base/tests/helper_bug1733509.html

@@ -0,0 +1,30 @@
+<html>
+<script src="/tests/SimpleTest/EventUtils.js"></script>
+<script src="/tests/SimpleTest/paint_listener.js"></script>
+<script src="/tests/SimpleTest/SimpleTest.js"></script>
+<script type="text/javascript" src="/tests/gfx/layers/apz/test/mochitest/apz_test_utils.js"></script>
+<style>
+    body {
+        margin: 0;
+        padding: 20;
+        background-color: blueviolet;
+    }
+
+    button {
+        margin: 0;
+    }
+</style>
+
+<body>
+    <button id="btn">Click me</button>
+</body>
+
+<script>
+    // Silence SimpleTest warning about missing assertions by having it wait
+    // indefinitely. We don't need to give it an explicit finish because the
+    // entire window this test runs in will be closed after the main browser test
+    // finished.
+    SimpleTest.waitForExplicitFinish();
+</script>
+
+</html>

layout/base/tests/mochitest.toml

@@ -247,6 +247,7 @@ support-files = ["file_dynamic_toolbar_max_height.html"]
 ["test_emulate_color_scheme.html"]
 
 ["test_event_target_radius.html"]
+support-files = ["helper_bug1733509.html"]
 skip-if = ["xorigin"] # JavaScript error: resource://specialpowers/SpecialPowersChild.sys.mjs, line 73: SecurityError: Permission denied to access property "windowUtils" on cross-origin object
 
 ["test_frame_reconstruction_body_table.html"]

layout/base/tests/test_event_target_radius.html

@@ -2,14 +2,19 @@
 <html id="html" style="height:100%">
 <!--
 https://bugzilla.mozilla.org/show_bug.cgi?id=780847
+https://bugzilla.mozilla.org/show_bug.cgi?id=1733509
 -->
 <head>
   <title>Test radii for mouse events</title>
-  <script src="/tests/SimpleTest/SimpleTest.js"></script>
   <script src="/tests/SimpleTest/EventUtils.js"></script>
+  <script src="/tests/SimpleTest/paint_listener.js"></script>
+  <script src="/tests/SimpleTest/SimpleTest.js"></script>
+  <script type="text/javascript" src="/tests/gfx/layers/apz/test/mochitest/apz_test_utils.js"></script>
   <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
   <style>
   .target { position:absolute; left:100px; top:100px; width:100px; height:100px; background:blue; }
+  .scaled { background: green; transform: scale(0.5); }
+  iframe { margin:0; padding:0; width:50; height:50; border:1px solid black; background:yellowgreen; }
   </style>
 </head>
 <body id="body" onload="setTimeout(startTest, 0)" style="margin:0; width:100%; height:100%; overflow:hidden">
@@ -73,6 +78,10 @@ https://bugzilla.mozilla.org/show_bug.cgi?id=780847
    <div id="t13_touchlistener" style="width: 50px; height: 50px; background:red" ontouchend="x=1"></div>
    <div id="t13_notouchlistener" style="width: 50px; height: 50px; background:green"></div>
   </div>
+
+  <div id="t14" class="target scaled" hidden>
+    <iframe id="t14iframe"></iframe>
+  </div>
 </div>
 <pre id="test">
 <script type="application/javascript">
@@ -414,7 +423,50 @@ function testTouchable() {
   testTouch("t13", 10, 50 - (2*mm), "t13_touchlistener", "touch inside t13_touchlistener bottom edge");
   setShowing("t13", false);
 
-  endTest();
+  test4();
+}
+
+// https://bugzilla.mozilla.org/show_bug.cgi?id=1733509
+function test4() {
+  // Skip non-Fission for now because of bug 1890522
+  if (SpecialPowers.Services.appinfo.fissionAutostart) {
+    waitUntilApzStable().then(async () => doTest4()).then(endTest);
+  } else {
+    endTest();
+  }
+}
+
+async function doTest4() {
+  setShowing("t14", true);
+
+  let iframeURL = SimpleTest.getTestFileURL("helper_bug1733509.html");
+  // todo: Also perform this test for an in-process iframe
+  // once bug 1890522 is fixed.
+  const iframe = document.querySelector("#t14iframe");
+  iframeURL = iframeURL.replace(window.location.origin, "https://example.com");
+  await setupIframe(iframe, iframeURL);
+
+  var result = await SpecialPowers.spawn(iframe, [], async () => {
+    await content.wrappedJSObject.waitUntilApzStable();
+    var iframeEventTarget = null;
+    content.window.onmousedown = function (event) { iframeEventTarget = event.target; };
+    content.wrappedJSObject.synthesizeMouse(content.document.documentElement, 2, 2, {});
+    return iframeEventTarget && iframeEventTarget.id === "btn";
+  });
+
+  ok(result, "Failed to target button inside iframe");
+  setShowing("t14", false);
+}
+
+async function setupIframe(aIFrame, aURL) {
+  const iframeLoadPromise = promiseOneEvent(aIFrame, "load", null);
+  aIFrame.src = aURL;
+  await iframeLoadPromise;
+
+  await SpecialPowers.spawn(aIFrame, [], async () => {
+    await content.wrappedJSObject.waitUntilApzStable();
+    await SpecialPowers.contentTransformsReceived(content);
+  });
 }
 </script>
 </pre>