From ab4314f6af279a25e967635a9427b0c2267b7f93 Mon Sep 17 00:00:00 2001
From: Mirko Brodesser <mbrodesser@mozilla.com>
Date: Fri, 29 Jan 2021 09:46:09 +0000
Subject: [PATCH] Bug 1688832: part 6) Hide
 `AccessibleCaretManager::Carets::mFirst`, `mSecond`. r=smaug

Helps to see that they're never replaced with new instances.

Differential Revision: https://phabricator.services.mozilla.com/D103313
---
 layout/base/AccessibleCaretManager.cpp           | 25 +++++++++++++++---------
 layout/base/AccessibleCaretManager.h             | 21 +++++++++++++++++++-
 layout/base/gtest/TestAccessibleCaretManager.cpp | 20 +++++++++----------
 3 files changed, 46 insertions(+), 20 deletions(-)

diff --git a/layout/base/AccessibleCaretManager.cpp b/layout/base/AccessibleCaretManager.cpp
index df63c27ef30c..48aabc8986a9 100644
--- a/layout/base/AccessibleCaretManager.cpp
+++ b/layout/base/AccessibleCaretManager.cpp
@@ -6,6 +6,8 @@
 
 #include "AccessibleCaretManager.h"
 
+#include <utility>
+
 #include "AccessibleCaret.h"
 #include "AccessibleCaretEventHub.h"
 #include "AccessibleCaretLogger.h"
@@ -77,22 +79,22 @@ std::ostream& operator<<(
 #undef AC_PROCESS_ENUM_TO_STREAM
 
 AccessibleCaretManager::AccessibleCaretManager(PresShell* aPresShell)
-    : mPresShell(aPresShell) {
-  if (!mPresShell) {
-    return;
-  }
+    : AccessibleCaretManager{
+          aPresShell,
+          Carets{aPresShell ? MakeUnique<AccessibleCaret>(aPresShell) : nullptr,
+                 aPresShell ? MakeUnique<AccessibleCaret>(aPresShell)
+                            : nullptr}} {}
 
-  mCarets.mFirst = MakeUnique<AccessibleCaret>(mPresShell);
-  mCarets.mSecond = MakeUnique<AccessibleCaret>(mPresShell);
-}
+AccessibleCaretManager::AccessibleCaretManager(PresShell* aPresShell,
+                                               Carets aCarets)
+    : mPresShell{aPresShell}, mCarets{std::move(aCarets)} {}
 
 AccessibleCaretManager::LayoutFlusher::~LayoutFlusher() {
   MOZ_RELEASE_ASSERT(!mFlushing, "Going away in MaybeFlush? Bad!");
 }
 
 void AccessibleCaretManager::Terminate() {
-  mCarets.mFirst = nullptr;
-  mCarets.mSecond = nullptr;
+  mCarets.Terminate();
   mActiveCaret = nullptr;
   mPresShell = nullptr;
 }
@@ -1492,4 +1494,9 @@ void AccessibleCaretManager::DispatchCaretStateChangedEvent(
   (new AsyncEventDispatcher(doc, event))->PostDOMEvent();
 }
 
+AccessibleCaretManager::Carets::Carets(UniquePtr<AccessibleCaret> aFirst,
+           UniquePtr<AccessibleCaret> aSecond)
+        : mFirst{std::move(aFirst)}, mSecond{std::move(aSecond)} {}
+
+
 }  // namespace mozilla
diff --git a/layout/base/AccessibleCaretManager.h b/layout/base/AccessibleCaretManager.h
index 3986835d2c52..28e0df657967 100644
--- a/layout/base/AccessibleCaretManager.h
+++ b/layout/base/AccessibleCaretManager.h
@@ -127,6 +127,11 @@ class AccessibleCaretManager {
   bool ShouldDisableApz() const;
 
  protected:
+  class Carets;
+
+  // @param aPresShell may be nullptr for testing.
+  AccessibleCaretManager(PresShell* aPresShell, Carets aCarets);
+
   // This enum representing the number of AccessibleCarets on the screen.
   enum class CaretMode : uint8_t {
     // No caret on the screen.
@@ -314,7 +319,15 @@ class AccessibleCaretManager {
   // nullptr either we are in gtest or PresShell::IsDestroying() is true.
   PresShell* MOZ_NON_OWNING_REF mPresShell = nullptr;
 
-  struct Carets {
+  class Carets {
+   public:
+    Carets(UniquePtr<AccessibleCaret> aFirst,
+           UniquePtr<AccessibleCaret> aSecond);
+
+    Carets(Carets&&) = default;
+    Carets(const Carets&) = delete;
+    Carets& operator=(const Carets&) = delete;
+
     AccessibleCaret* GetFirst() const { return mFirst.get(); }
 
     AccessibleCaret* GetSecond() const { return mSecond.get(); }
@@ -327,6 +340,12 @@ class AccessibleCaretManager {
       return mFirst->IsVisuallyVisible() || mSecond->IsVisuallyVisible();
     }
 
+    void Terminate() {
+      mFirst = nullptr;
+      mSecond = nullptr;
+    }
+
+   private:
     // First caret is attached to nsCaret in cursor mode, and is attached to
     // selection highlight as the left caret in selection mode.
     UniquePtr<AccessibleCaret> mFirst;
diff --git a/layout/base/gtest/TestAccessibleCaretManager.cpp b/layout/base/gtest/TestAccessibleCaretManager.cpp
index 46eb004474cf..d23558a18294 100644
--- a/layout/base/gtest/TestAccessibleCaretManager.cpp
+++ b/layout/base/gtest/TestAccessibleCaretManager.cpp
@@ -63,17 +63,17 @@ class AccessibleCaretManagerTester : public ::testing::Test {
     using AccessibleCaretManager::HideCaretsAndDispatchCaretStateChangedEvent;
     using AccessibleCaretManager::UpdateCarets;
 
-    MockAccessibleCaretManager() : AccessibleCaretManager(nullptr) {
-      mCarets.mFirst = MakeUnique<MockAccessibleCaret>();
-      mCarets.mSecond = MakeUnique<MockAccessibleCaret>();
-    }
+    MockAccessibleCaretManager()
+        : AccessibleCaretManager(nullptr,
+                                 Carets{MakeUnique<MockAccessibleCaret>(),
+                                        MakeUnique<MockAccessibleCaret>()}) {}
 
     MockAccessibleCaret& FirstCaret() {
-      return static_cast<MockAccessibleCaret&>(*mCarets.mFirst);
+      return static_cast<MockAccessibleCaret&>(*mCarets.GetFirst());
     }
 
     MockAccessibleCaret& SecondCaret() {
-      return static_cast<MockAccessibleCaret&>(*mCarets.mSecond);
+      return static_cast<MockAccessibleCaret&>(*mCarets.GetSecond());
     }
 
     bool CompareTreePosition(nsIFrame* aStartFrame,
@@ -91,11 +91,11 @@ class AccessibleCaretManagerTester : public ::testing::Test {
 
     void UpdateCaretsForAlwaysTilt(const nsIFrame* aStartFrame,
                                    const nsIFrame* aEndFrame) override {
-      if (mCarets.mFirst->IsVisuallyVisible()) {
-        mCarets.mFirst->SetAppearance(Appearance::Left);
+      if (mCarets.GetFirst()->IsVisuallyVisible()) {
+        mCarets.GetFirst()->SetAppearance(Appearance::Left);
       }
-      if (mCarets.mSecond->IsVisuallyVisible()) {
-        mCarets.mSecond->SetAppearance(Appearance::Right);
+      if (mCarets.GetSecond()->IsVisuallyVisible()) {
+        mCarets.GetSecond()->SetAppearance(Appearance::Right);
       }
     }
 
-- 
2.11.4.GIT