1 files changed, 229 insertions, 0 deletions
diff --git a/dom/xul/ChromeObserver.cpp b/dom/xul/ChromeObserver.cpp
new file mode 100644
index 0000000000..092641d493
--- /dev/null
+++ b/dom/xul/ChromeObserver.cpp
@@ -0,0 +1,229 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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 https://mozilla.org/MPL/2.0/. */
+
+#include "ChromeObserver.h"
+
+#include "nsIBaseWindow.h"
+#include "nsIWidget.h"
+#include "nsIFrame.h"
+
+#include "nsContentUtils.h"
+#include "nsView.h"
+#include "nsPresContext.h"
+#include "mozilla/dom/Document.h"
+#include "mozilla/dom/DocumentInlines.h"
+#include "mozilla/dom/Element.h"
+#include "mozilla/dom/MutationEventBinding.h"
+#include "nsXULElement.h"
+
+namespace mozilla::dom {
+
+NS_IMPL_ISUPPORTS(ChromeObserver, nsIMutationObserver)
+
+ChromeObserver::ChromeObserver(Document* aDocument)
+    : nsStubMutationObserver(), mDocument(aDocument) {}
+
+ChromeObserver::~ChromeObserver() = default;
+
+void ChromeObserver::Init() {
+  mDocument->AddMutationObserver(this);
+  Element* rootElement = mDocument->GetRootElement();
+  if (!rootElement) {
+    return;
+  }
+  nsAutoScriptBlocker scriptBlocker;
+  uint32_t attributeCount = rootElement->GetAttrCount();
+  for (uint32_t i = 0; i < attributeCount; i++) {
+    BorrowedAttrInfo info = rootElement->GetAttrInfoAt(i);
+    const nsAttrName* name = info.mName;
+    if (name->LocalName() == nsGkAtoms::chromemargin) {
+      // Some linux windows managers have an issue when the chrome margin is
+      // applied while the browser is loading (bug 1598848). For now, skip
+      // applying this attribute when initializing.
+      continue;
+    }
+    AttributeChanged(rootElement, name->NamespaceID(), name->LocalName(),
+                     MutationEvent_Binding::ADDITION, nullptr);
+  }
+}
+
+nsIWidget* ChromeObserver::GetWindowWidget() {
+  // only top level chrome documents can set the titlebar color
+  if (mDocument && mDocument->IsRootDisplayDocument()) {
+    nsCOMPtr<nsISupports> container = mDocument->GetContainer();
+    nsCOMPtr<nsIBaseWindow> baseWindow = do_QueryInterface(container);
+    if (baseWindow) {
+      nsCOMPtr<nsIWidget> mainWidget;
+      baseWindow->GetMainWidget(getter_AddRefs(mainWidget));
+      return mainWidget;
+    }
+  }
+  return nullptr;
+}
+
+class SetDrawInTitleBarEvent : public Runnable {
+ public:
+  SetDrawInTitleBarEvent(nsIWidget* aWidget, bool aState)
+      : mozilla::Runnable("SetDrawInTitleBarEvent"),
+        mWidget(aWidget),
+        mState(aState) {}
+
+  NS_IMETHOD Run() override {
+    NS_ASSERTION(mWidget,
+                 "You shouldn't call this runnable with a null widget!");
+
+    mWidget->SetDrawsInTitlebar(mState);
+    return NS_OK;
+  }
+
+ private:
+  nsCOMPtr<nsIWidget> mWidget;
+  bool mState;
+};
+
+void ChromeObserver::SetDrawsInTitlebar(bool aState) {
+  nsIWidget* mainWidget = GetWindowWidget();
+  if (mainWidget) {
+    nsContentUtils::AddScriptRunner(
+        new SetDrawInTitleBarEvent(mainWidget, aState));
+  }
+}
+
+void ChromeObserver::SetDrawsTitle(bool aState) {
+  nsIWidget* mainWidget = GetWindowWidget();
+  if (mainWidget) {
+    // We can do this synchronously because SetDrawsTitle doesn't have any
+    // synchronous effects apart from a harmless invalidation.
+    mainWidget->SetDrawsTitle(aState);
+  }
+}
+
+class MarginSetter : public Runnable {
+ public:
+  explicit MarginSetter(nsIWidget* aWidget)
+      : mozilla::Runnable("MarginSetter"),
+        mWidget(aWidget),
+        mMargin(-1, -1, -1, -1) {}
+  MarginSetter(nsIWidget* aWidget, const LayoutDeviceIntMargin& aMargin)
+      : mozilla::Runnable("MarginSetter"), mWidget(aWidget), mMargin(aMargin) {}
+
+  NS_IMETHOD Run() override {
+    // SetNonClientMargins can dispatch native events, hence doing
+    // it off a script runner.
+    mWidget->SetNonClientMargins(mMargin);
+    return NS_OK;
+  }
+
+ private:
+  nsCOMPtr<nsIWidget> mWidget;
+  LayoutDeviceIntMargin mMargin;
+};
+
+void ChromeObserver::SetChromeMargins(const nsAttrValue* aValue) {
+  if (!aValue) return;
+
+  nsIWidget* mainWidget = GetWindowWidget();
+  if (!mainWidget) return;
+
+  // top, right, bottom, left - see nsAttrValue
+  nsAutoString tmp;
+  aValue->ToString(tmp);
+  nsIntMargin margins;
+  if (nsContentUtils::ParseIntMarginValue(tmp, margins)) {
+    nsContentUtils::AddScriptRunner(new MarginSetter(
+        mainWidget, LayoutDeviceIntMargin::FromUnknownMargin(margins)));
+  }
+}
+
+void ChromeObserver::AttributeChanged(dom::Element* aElement,
+                                      int32_t aNamespaceID, nsAtom* aName,
+                                      int32_t aModType,
+                                      const nsAttrValue* aOldValue) {
+  // We only care about changes to the root element.
+  if (!mDocument || aElement != mDocument->GetRootElement()) {
+    return;
+  }
+
+  const nsAttrValue* value = aElement->GetParsedAttr(aName, aNamespaceID);
+  if (value) {
+    // Hide chrome if needed
+    if (aName == nsGkAtoms::hidechrome) {
+      HideWindowChrome(value->Equals(u"true"_ns, eCaseMatters));
+    } else if (aName == nsGkAtoms::chromemargin) {
+      SetChromeMargins(value);
+    }
+    // title and drawintitlebar are settable on
+    // any root node (windows, dialogs, etc)
+    else if (aName == nsGkAtoms::title) {
+      mDocument->NotifyPossibleTitleChange(false);
+    } else if (aName == nsGkAtoms::drawintitlebar) {
+      SetDrawsInTitlebar(value->Equals(u"true"_ns, eCaseMatters));
+    } else if (aName == nsGkAtoms::drawtitle) {
+      SetDrawsTitle(value->Equals(u"true"_ns, eCaseMatters));
+    } else if (aName == nsGkAtoms::localedir) {
+      // if the localedir changed on the root element, reset the document
+      // direction
+      mDocument->ResetDocumentDirection();
+    } else if (aName == nsGkAtoms::lwtheme) {
+      // if the lwtheme changed, make sure to reset the document lwtheme
+      // cache
+      mDocument->ResetDocumentLWTheme();
+    }
+  } else {
+    if (aName == nsGkAtoms::hidechrome) {
+      HideWindowChrome(false);
+    } else if (aName == nsGkAtoms::chromemargin) {
+      ResetChromeMargins();
+    } else if (aName == nsGkAtoms::localedir) {
+      // if the localedir changed on the root element, reset the document
+      // direction
+      mDocument->ResetDocumentDirection();
+    } else if (aName == nsGkAtoms::lwtheme) {
+      // if the lwtheme changed, make sure to restyle appropriately
+      mDocument->ResetDocumentLWTheme();
+    } else if (aName == nsGkAtoms::drawintitlebar) {
+      SetDrawsInTitlebar(false);
+    } else if (aName == nsGkAtoms::drawtitle) {
+      SetDrawsTitle(false);
+    }
+  }
+}
+
+void ChromeObserver::NodeWillBeDestroyed(nsINode* aNode) {
+  mDocument = nullptr;
+}
+
+void ChromeObserver::ResetChromeMargins() {
+  nsIWidget* mainWidget = GetWindowWidget();
+  if (!mainWidget) return;
+  // See nsIWidget
+  nsContentUtils::AddScriptRunner(new MarginSetter(mainWidget));
+}
+
+nsresult ChromeObserver::HideWindowChrome(bool aShouldHide) {
+  // only top level chrome documents can hide the window chrome
+  if (!mDocument->IsRootDisplayDocument()) return NS_OK;
+
+  nsPresContext* presContext = mDocument->GetPresContext();
+
+  if (presContext && presContext->IsChrome()) {
+    nsIFrame* frame = mDocument->GetDocumentElement()->GetPrimaryFrame();
+
+    if (frame) {
+      nsView* view = frame->GetClosestView();
+
+      if (view) {
+        nsIWidget* w = view->GetWidget();
+        NS_ENSURE_STATE(w);
+        w->HideWindowChrome(aShouldHide);
+      }
+    }
+  }
+
+  return NS_OK;
+}
+
+}  // namespace mozilla::dom