Bug 1786668 - Add a test case that MobileViewportManager is properly …

…updated when browser window moves from a HiDPI monitor to normal one. r=tnikkel Unfortunately this test doesn't run as expected on our CI since macs on our CI are running normal DPI mode. I tested this test works properly on my macbook, it fails without the fix in the previous commit and it passes with the fix. Differential Revision: https://phabricator.services.mozilla.com/D153688
dothq · Aug 26, 2022 · 4917d58 · 4917d58
1 parent 2f8576f
commit 4917d58
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diff --git a/dom/base/nsDOMWindowUtils.cpp b/dom/base/nsDOMWindowUtils.cpp
@@ -4809,3 +4809,19 @@ nsDOMWindowUtils::GetOrientationLock(uint32_t* aOrientationLock) {
   *aOrientationLock = static_cast<uint32_t>(bc->GetOrientationLock());
   return NS_OK;
 }
+
+NS_IMETHODIMP
+nsDOMWindowUtils::SetHiDPIMode(bool aHiDPI) {
+  nsCOMPtr<nsIWidget> widget = GetWidget();
+  if (!widget) return NS_ERROR_FAILURE;
+
+  return widget->SetHiDPIMode(aHiDPI);
+}
+
+NS_IMETHODIMP
+nsDOMWindowUtils::RestoreHiDPIMode() {
+  nsCOMPtr<nsIWidget> widget = GetWidget();
+  if (!widget) return NS_ERROR_FAILURE;
+
+  return widget->RestoreHiDPIMode();
+}
diff --git a/dom/interfaces/base/nsIDOMWindowUtils.idl b/dom/interfaces/base/nsIDOMWindowUtils.idl
@@ -2208,6 +2208,16 @@ interface nsIDOMWindowUtils : nsISupports {
 
   bool isCoepCredentialless();
 
+  /**
+   * Simulate enabling/disabling HiDPI mode. This function only works on
+   * environments where HiDPI mode is available by default.
+   */
+  void setHiDPIMode(in boolean aHiDPI);
+  /**
+   * Restore the simulated HiDPI mode.
+   */
+  void restoreHiDPIMode();
+
   /**
    * NOTE: Currently works only on GTK+.
    */

diff --git a/layout/base/tests/browser.ini b/layout/base/tests/browser.ini
@@ -9,6 +9,8 @@ support-files =
 [browser_bug1701027-2.js]
 support-files =
   helper_bug1701027-2.html
+[browser_bug1757410.js]
+run-if = (os == 'mac')
 [browser_disableDialogs_onbeforeunload.js]
 [browser_onbeforeunload_only_after_interaction.js]
 [browser_onbeforeunload_only_after_interaction_in_frame.js]

diff --git a/layout/base/tests/browser_bug1757410.js b/layout/base/tests/browser_bug1757410.js
@@ -0,0 +1,59 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+"use strict";
+
+const PAGECONTENT =
+  "<!DOCTYPE html>" +
+  "<html>" +
+  "<style>" +
+  "html { " +
+  "  height: 120vh;" +
+  "  overflow-y: scroll;" +
+  "}" +
+  "</style>" +
+  "</html>";
+
+const pageUrl = "data:text/html," + encodeURIComponent(PAGECONTENT);
+
+add_task(async function test() {
+  if (window.devicePixelRatio != 2) {
+    ok(
+      true,
+      "Skip this test since this test is supposed to run on HiDPI mode, " +
+        "the devixePixelRato on this machine is " +
+        window.devicePixelRatio
+    );
+    return;
+  }
+
+  const tab = await BrowserTestUtils.openNewForegroundTab(gBrowser, pageUrl);
+
+  // Scroll the content a bit.
+  const originalScrollPosition = await SpecialPowers.spawn(
+    tab.linkedBrowser,
+    [],
+    async () => {
+      content.document.scrollingElement.scrollTop = 100;
+      return content.document.scrollingElement.scrollTop;
+    }
+  );
+
+  // Disabling HiDPI mode and check the scroll position.
+  SpecialPowers.DOMWindowUtils.setHiDPIMode(false);
+  const scrollPosition = await SpecialPowers.spawn(
+    tab.linkedBrowser,
+    [],
+    async () => {
+      return content.document.scrollingElement.scrollTop;
+    }
+  );
+  is(
+    originalScrollPosition,
+    scrollPosition,
+    "The scroll position should be kept"
+  );
+  BrowserTestUtils.removeTab(tab);
+
+  SpecialPowers.DOMWindowUtils.restoreHiDPIMode();
+});
diff --git a/widget/cocoa/nsChildView.h b/widget/cocoa/nsChildView.h
@@ -507,6 +507,10 @@ class nsChildView final : public nsBaseWidget {
   // Called by nsCocoaWindow when the window's fullscreen state changes.
   void UpdateFullscreen(bool aFullscreen);
 
+  // test only.
+  virtual nsresult SetHiDPIMode(bool aHiDPI) override;
+  virtual nsresult RestoreHiDPIMode() override;
+
  protected:
   virtual ~nsChildView();
 

diff --git a/widget/cocoa/nsChildView.mm b/widget/cocoa/nsChildView.mm
@@ -4641,6 +4641,20 @@ - (void)pressureChangeWithEvent:(NSEvent*)event {
   NS_OBJC_END_TRY_BLOCK_RETURN(NS_ERROR_FAILURE);
 }
 
+nsresult nsChildView::SetHiDPIMode(bool aHiDPI) {
+  nsCocoaUtils::InvalidateHiDPIState();
+  Preferences::SetInt("gfx.hidpi.enabled", aHiDPI ? 1 : 0);
+  BackingScaleFactorChanged();
+  return NS_OK;
+}
+
+nsresult nsChildView::RestoreHiDPIMode() {
+  nsCocoaUtils::InvalidateHiDPIState();
+  Preferences::ClearUser("gfx.hidpi.enabled");
+  BackingScaleFactorChanged();
+  return NS_OK;
+}
+
 #pragma mark -
 
 #ifdef ACCESSIBILITY

diff --git a/widget/cocoa/nsCocoaUtils.h b/widget/cocoa/nsCocoaUtils.h
@@ -453,6 +453,8 @@ class nsCocoaUtils {
    */
   static nsresult MaybeRequestScreenCapturePermission();
 
+  static void InvalidateHiDPIState();
+
  private:
   /**
    * Completion handlers used as an argument to the macOS API to

diff --git a/widget/cocoa/nsCocoaUtils.mm b/widget/cocoa/nsCocoaUtils.mm
@@ -755,6 +755,9 @@ static bool ComputeIsEntirelyBlack(const DataSourceSurface::MappedSurface& aMap,
   return sHiDPIEnabled;
 }
 
+// static
+void nsCocoaUtils::InvalidateHiDPIState() { sHiDPIPrefInitialized = false; }
+
 void nsCocoaUtils::GetCommandsFromKeyEvent(NSEvent* aEvent,
                                            nsTArray<KeyBindingsCommand>& aCommands) {
   NS_OBJC_BEGIN_TRY_IGNORE_BLOCK;

diff --git a/widget/nsIWidget.h b/widget/nsIWidget.h
@@ -2121,6 +2121,11 @@ class nsIWidget : public nsISupports {
   virtual void SetWindowButtonRect(WindowButtonType aButtonType,
                                    const LayoutDeviceIntRect& aClientRect) {}
 
+  virtual nsresult SetHiDPIMode(bool aHiDPI) {
+    return NS_ERROR_NOT_IMPLEMENTED;
+  }
+  virtual nsresult RestoreHiDPIMode() { return NS_ERROR_NOT_IMPLEMENTED; }
+
  protected:
   // keep the list of children.  We also keep track of our siblings.
   // The ownership model is as follows: parent holds a strong ref to