diff -r 000000000000 -r 6474c204b198 gfx/src/nsITheme.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/src/nsITheme.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,174 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * 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/. */
+
+/* service providing platform-specific native rendering for widgets */
+
+#ifndef nsITheme_h_
+#define nsITheme_h_
+
+#include "nsISupports.h"
+#include "nsCOMPtr.h"
+#include "nsColor.h"
+
+struct nsRect;
+struct nsIntRect;
+struct nsIntSize;
+class nsIntRegion;
+struct nsFont;
+struct nsIntMargin;
+class nsPresContext;
+class nsRenderingContext;
+class nsDeviceContext;
+class nsIFrame;
+class nsIContent;
+class nsIAtom;
+class nsIWidget;
+
+// IID for the nsITheme interface
+// {b0f3efe9-0bd4-4f6b-8daa-0ec7f6006822}
+ #define NS_ITHEME_IID     \
+{ 0x4440b5c7, 0xd8bd, 0x4d9c, \
+  { 0x9c, 0x3e, 0xa5, 0xe6, 0x26, 0x81, 0x10, 0xa0 } }
+// {D930E29B-6909-44e5-AB4B-AF10D6923705}
+#define NS_THEMERENDERER_CID \
+{ 0x9020805b, 0x14a3, 0x4125, \
+  { 0xa5, 0x63, 0x4a, 0x8c, 0x5d, 0xe0, 0xa9, 0xa3 } }
+
+/**
+ * nsITheme is a service that provides platform-specific native
+ * rendering for widgets.  In other words, it provides the necessary
+ * operations to draw a rendering object (an nsIFrame) as a native
+ * widget.
+ *
+ * All the methods on nsITheme take a rendering context or device
+ * context, a frame (the rendering object), and a widget type (one of
+ * the constants in nsThemeConstants.h).
+ */
+class nsITheme: public nsISupports {
+public:
+  NS_DECLARE_STATIC_IID_ACCESSOR(NS_ITHEME_IID)
+
+  /**
+   * Draw the actual theme background.
+   * @param aContext the context to draw into
+   * @param aFrame the frame for the widget that we're drawing
+   * @param aWidgetType the -moz-appearance value to draw
+   * @param aRect the rectangle defining the area occupied by the widget
+   * @param aDirtyRect the rectangle that needs to be drawn
+   */
+  NS_IMETHOD DrawWidgetBackground(nsRenderingContext* aContext,
+                                  nsIFrame* aFrame,
+                                  uint8_t aWidgetType,
+                                  const nsRect& aRect,
+                                  const nsRect& aDirtyRect) = 0;
+
+  /**
+   * Get the computed CSS border for the widget, in pixels.
+   */
+  NS_IMETHOD GetWidgetBorder(nsDeviceContext* aContext, 
+                             nsIFrame* aFrame,
+                             uint8_t aWidgetType,
+                             nsIntMargin* aResult)=0;
+
+  /**
+   * This method can return false to indicate that the CSS padding
+   * value should be used.  Otherwise, it will fill in aResult with the
+   * computed padding, in pixels, and return true.
+   *
+   * XXXldb This ought to be required to return true for non-containers
+   * so that we don't let specified padding that has no effect change
+   * the computed padding and potentially the size.
+   */
+  virtual bool GetWidgetPadding(nsDeviceContext* aContext,
+                                  nsIFrame* aFrame,
+                                  uint8_t aWidgetType,
+                                  nsIntMargin* aResult) = 0;
+
+  /**
+   * On entry, *aResult is positioned at 0,0 and sized to the new size
+   * of aFrame (aFrame->GetSize() may be stale and should not be used).
+   * This method can return false to indicate that no special
+   * overflow area is required by the native widget. Otherwise it will
+   * fill in aResult with the desired overflow area, in appunits, relative
+   * to the frame origin, and return true.
+   *
+   * This overflow area is used to determine what area needs to be
+   * repainted when the widget changes.  However, it does not affect the
+   * widget's size or what area is reachable by scrollbars.  (In other
+   * words, in layout terms, it affects visual overflow but not
+   * scrollable overflow.)
+   */
+  virtual bool GetWidgetOverflow(nsDeviceContext* aContext,
+                                   nsIFrame* aFrame,
+                                   uint8_t aWidgetType,
+                                   /*INOUT*/ nsRect* aOverflowRect)
+  { return false; }
+
+  /**
+   * Get the minimum border-box size of a widget, in *pixels* (in
+   * |aResult|).  If |aIsOverridable| is set to true, this size is a
+   * minimum size; if false, this size is the only valid size for the
+   * widget.
+   */
+  NS_IMETHOD GetMinimumWidgetSize(nsRenderingContext* aContext,
+                                  nsIFrame* aFrame,
+                                  uint8_t aWidgetType,
+                                  nsIntSize* aResult,
+                                  bool* aIsOverridable)=0;
+
+
+  enum Transparency {
+    eOpaque = 0,
+    eTransparent,
+    eUnknownTransparency
+  };
+
+  /**
+   * Returns what we know about the transparency of the widget.
+   */
+  virtual Transparency GetWidgetTransparency(nsIFrame* aFrame, uint8_t aWidgetType)
+  { return eUnknownTransparency; }
+
+  NS_IMETHOD WidgetStateChanged(nsIFrame* aFrame, uint8_t aWidgetType, 
+                                nsIAtom* aAttribute, bool* aShouldRepaint)=0;
+
+  NS_IMETHOD ThemeChanged()=0;
+
+  virtual bool WidgetAppearanceDependsOnWindowFocus(uint8_t aWidgetType)
+  { return false; }
+
+  /**
+   * Can the nsITheme implementation handle this widget?
+   */
+  virtual bool ThemeSupportsWidget(nsPresContext* aPresContext,
+                                     nsIFrame* aFrame,
+                                     uint8_t aWidgetType)=0;
+
+  virtual bool WidgetIsContainer(uint8_t aWidgetType)=0;
+
+  /**
+   * Does the nsITheme implementation draw its own focus ring for this widget?
+   */
+  virtual bool ThemeDrawsFocusForWidget(uint8_t aWidgetType)=0;
+  
+  /**
+    * Should we insert a dropmarker inside of combobox button?
+   */
+  virtual bool ThemeNeedsComboboxDropmarker()=0;
+
+  /**
+   * Should we hide scrollbars?
+   */
+  virtual bool ShouldHideScrollbars()
+  { return false; }
+};
+
+NS_DEFINE_STATIC_IID_ACCESSOR(nsITheme, NS_ITHEME_IID)
+
+// Creator function
+extern nsresult NS_NewNativeTheme(nsISupports *aOuter, REFNSIID aIID, void **aResult);
+
+#endif