1 files changed, 143 insertions, 0 deletions
diff --git a/layout/xul/nsScrollbarFrame.h b/layout/xul/nsScrollbarFrame.h
new file mode 100644
index 0000000000..fc5bf2744e
--- /dev/null
+++ b/layout/xul/nsScrollbarFrame.h
@@ -0,0 +1,143 @@
+/* -*- 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 http://mozilla.org/MPL/2.0/. */
+
+//
+// nsScrollbarFrame
+//
+
+#ifndef nsScrollbarFrame_h__
+#define nsScrollbarFrame_h__
+
+#include "mozilla/Attributes.h"
+#include "nsIAnonymousContentCreator.h"
+#include "nsBoxFrame.h"
+
+class nsIScrollbarMediator;
+
+namespace mozilla {
+class PresShell;
+namespace dom {
+class Element;
+}
+}  // namespace mozilla
+
+nsIFrame* NS_NewScrollbarFrame(mozilla::PresShell* aPresShell,
+                               mozilla::ComputedStyle* aStyle);
+
+class nsScrollbarFrame final : public nsBoxFrame,
+                               public nsIAnonymousContentCreator {
+  using Element = mozilla::dom::Element;
+
+ public:
+  explicit nsScrollbarFrame(ComputedStyle* aStyle, nsPresContext* aPresContext)
+      : nsBoxFrame(aStyle, aPresContext, kClassID),
+        mIncrement(0),
+        mSmoothScroll(false),
+        mScrollbarMediator(nullptr),
+        mUpTopButton(nullptr),
+        mDownTopButton(nullptr),
+        mSlider(nullptr),
+        mThumb(nullptr),
+        mUpBottomButton(nullptr),
+        mDownBottomButton(nullptr) {}
+
+  NS_DECL_QUERYFRAME
+  NS_DECL_FRAMEARENA_HELPERS(nsScrollbarFrame)
+
+#ifdef DEBUG_FRAME_DUMP
+  virtual nsresult GetFrameName(nsAString& aResult) const override {
+    return MakeFrameName(u"ScrollbarFrame"_ns, aResult);
+  }
+#endif
+
+  // nsIFrame overrides
+  virtual nsresult AttributeChanged(int32_t aNameSpaceID, nsAtom* aAttribute,
+                                    int32_t aModType) override;
+
+  NS_IMETHOD HandlePress(nsPresContext* aPresContext,
+                         mozilla::WidgetGUIEvent* aEvent,
+                         nsEventStatus* aEventStatus) override;
+
+  NS_IMETHOD HandleMultiplePress(nsPresContext* aPresContext,
+                                 mozilla::WidgetGUIEvent* aEvent,
+                                 nsEventStatus* aEventStatus,
+                                 bool aControlHeld) override;
+
+  MOZ_CAN_RUN_SCRIPT
+  NS_IMETHOD HandleDrag(nsPresContext* aPresContext,
+                        mozilla::WidgetGUIEvent* aEvent,
+                        nsEventStatus* aEventStatus) override;
+
+  NS_IMETHOD HandleRelease(nsPresContext* aPresContext,
+                           mozilla::WidgetGUIEvent* aEvent,
+                           nsEventStatus* aEventStatus) override;
+
+  virtual void DestroyFrom(nsIFrame* aDestructRoot,
+                           PostDestroyData& aPostDestroyData) override;
+
+  virtual void Init(nsIContent* aContent, nsContainerFrame* aParent,
+                    nsIFrame* aPrevInFlow) override;
+
+  virtual void Reflow(nsPresContext* aPresContext, ReflowOutput& aDesiredSize,
+                      const ReflowInput& aReflowInput,
+                      nsReflowStatus& aStatus) override;
+
+  void SetScrollbarMediatorContent(nsIContent* aMediator);
+  nsIScrollbarMediator* GetScrollbarMediator();
+
+  // nsBox methods
+
+  /**
+   * Treat scrollbars as clipping their children; overflowing children
+   * will not be allowed to set an overflow rect on this
+   * frame. This means that when the scroll code decides to hide a
+   * scrollframe by setting its height or width to zero, that will
+   * hide the children too.
+   */
+  virtual bool DoesClipChildrenInBothAxes() override { return true; }
+
+  virtual nsresult GetXULMargin(nsMargin& aMargin) override;
+
+  /**
+   * The following three methods set the value of mIncrement when a
+   * scrollbar button is pressed.
+   */
+  void SetIncrementToLine(int32_t aDirection);
+  void SetIncrementToPage(int32_t aDirection);
+  void SetIncrementToWhole(int32_t aDirection);
+  /**
+   * MoveToNewPosition() adds mIncrement to the current position and
+   * updates the curpos attribute.
+   * @returns The new position after clamping, in CSS Pixels
+   * @note This method might destroy the frame, pres shell, and other objects.
+   */
+  int32_t MoveToNewPosition();
+  int32_t GetIncrement() { return mIncrement; }
+
+  // nsIAnonymousContentCreator
+  virtual nsresult CreateAnonymousContent(
+      nsTArray<ContentInfo>& aElements) override;
+  virtual void AppendAnonymousContentTo(nsTArray<nsIContent*>& aElements,
+                                        uint32_t aFilter) override;
+
+  void UpdateChildrenAttributeValue(nsAtom* aAttribute, bool aNotify);
+
+ protected:
+  int32_t mIncrement;  // Amount to scroll, in CSSPixels
+  bool mSmoothScroll;
+
+ private:
+  nsCOMPtr<nsIContent> mScrollbarMediator;
+
+  nsCOMPtr<Element> mUpTopButton;
+  nsCOMPtr<Element> mDownTopButton;
+  nsCOMPtr<Element> mSlider;
+  nsCOMPtr<Element> mThumb;
+  nsCOMPtr<Element> mUpBottomButton;
+  nsCOMPtr<Element> mDownBottomButton;
+};  // class nsScrollbarFrame
+
+#endif