michael@0: /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
michael@0:  *
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: /* service providing platform-specific native rendering for widgets */
michael@0: 
michael@0: #ifndef nsITheme_h_
michael@0: #define nsITheme_h_
michael@0: 
michael@0: #include "nsISupports.h"
michael@0: #include "nsCOMPtr.h"
michael@0: #include "nsColor.h"
michael@0: 
michael@0: struct nsRect;
michael@0: struct nsIntRect;
michael@0: struct nsIntSize;
michael@0: class nsIntRegion;
michael@0: struct nsFont;
michael@0: struct nsIntMargin;
michael@0: class nsPresContext;
michael@0: class nsRenderingContext;
michael@0: class nsDeviceContext;
michael@0: class nsIFrame;
michael@0: class nsIContent;
michael@0: class nsIAtom;
michael@0: class nsIWidget;
michael@0: 
michael@0: // IID for the nsITheme interface
michael@0: // {b0f3efe9-0bd4-4f6b-8daa-0ec7f6006822}
michael@0:  #define NS_ITHEME_IID     \
michael@0: { 0x4440b5c7, 0xd8bd, 0x4d9c, \
michael@0:   { 0x9c, 0x3e, 0xa5, 0xe6, 0x26, 0x81, 0x10, 0xa0 } }
michael@0: // {D930E29B-6909-44e5-AB4B-AF10D6923705}
michael@0: #define NS_THEMERENDERER_CID \
michael@0: { 0x9020805b, 0x14a3, 0x4125, \
michael@0:   { 0xa5, 0x63, 0x4a, 0x8c, 0x5d, 0xe0, 0xa9, 0xa3 } }
michael@0: 
michael@0: /**
michael@0:  * nsITheme is a service that provides platform-specific native
michael@0:  * rendering for widgets.  In other words, it provides the necessary
michael@0:  * operations to draw a rendering object (an nsIFrame) as a native
michael@0:  * widget.
michael@0:  *
michael@0:  * All the methods on nsITheme take a rendering context or device
michael@0:  * context, a frame (the rendering object), and a widget type (one of
michael@0:  * the constants in nsThemeConstants.h).
michael@0:  */
michael@0: class nsITheme: public nsISupports {
michael@0: public:
michael@0:   NS_DECLARE_STATIC_IID_ACCESSOR(NS_ITHEME_IID)
michael@0: 
michael@0:   /**
michael@0:    * Draw the actual theme background.
michael@0:    * @param aContext the context to draw into
michael@0:    * @param aFrame the frame for the widget that we're drawing
michael@0:    * @param aWidgetType the -moz-appearance value to draw
michael@0:    * @param aRect the rectangle defining the area occupied by the widget
michael@0:    * @param aDirtyRect the rectangle that needs to be drawn
michael@0:    */
michael@0:   NS_IMETHOD DrawWidgetBackground(nsRenderingContext* aContext,
michael@0:                                   nsIFrame* aFrame,
michael@0:                                   uint8_t aWidgetType,
michael@0:                                   const nsRect& aRect,
michael@0:                                   const nsRect& aDirtyRect) = 0;
michael@0: 
michael@0:   /**
michael@0:    * Get the computed CSS border for the widget, in pixels.
michael@0:    */
michael@0:   NS_IMETHOD GetWidgetBorder(nsDeviceContext* aContext, 
michael@0:                              nsIFrame* aFrame,
michael@0:                              uint8_t aWidgetType,
michael@0:                              nsIntMargin* aResult)=0;
michael@0: 
michael@0:   /**
michael@0:    * This method can return false to indicate that the CSS padding
michael@0:    * value should be used.  Otherwise, it will fill in aResult with the
michael@0:    * computed padding, in pixels, and return true.
michael@0:    *
michael@0:    * XXXldb This ought to be required to return true for non-containers
michael@0:    * so that we don't let specified padding that has no effect change
michael@0:    * the computed padding and potentially the size.
michael@0:    */
michael@0:   virtual bool GetWidgetPadding(nsDeviceContext* aContext,
michael@0:                                   nsIFrame* aFrame,
michael@0:                                   uint8_t aWidgetType,
michael@0:                                   nsIntMargin* aResult) = 0;
michael@0: 
michael@0:   /**
michael@0:    * On entry, *aResult is positioned at 0,0 and sized to the new size
michael@0:    * of aFrame (aFrame->GetSize() may be stale and should not be used).
michael@0:    * This method can return false to indicate that no special
michael@0:    * overflow area is required by the native widget. Otherwise it will
michael@0:    * fill in aResult with the desired overflow area, in appunits, relative
michael@0:    * to the frame origin, and return true.
michael@0:    *
michael@0:    * This overflow area is used to determine what area needs to be
michael@0:    * repainted when the widget changes.  However, it does not affect the
michael@0:    * widget's size or what area is reachable by scrollbars.  (In other
michael@0:    * words, in layout terms, it affects visual overflow but not
michael@0:    * scrollable overflow.)
michael@0:    */
michael@0:   virtual bool GetWidgetOverflow(nsDeviceContext* aContext,
michael@0:                                    nsIFrame* aFrame,
michael@0:                                    uint8_t aWidgetType,
michael@0:                                    /*INOUT*/ nsRect* aOverflowRect)
michael@0:   { return false; }
michael@0: 
michael@0:   /**
michael@0:    * Get the minimum border-box size of a widget, in *pixels* (in
michael@0:    * |aResult|).  If |aIsOverridable| is set to true, this size is a
michael@0:    * minimum size; if false, this size is the only valid size for the
michael@0:    * widget.
michael@0:    */
michael@0:   NS_IMETHOD GetMinimumWidgetSize(nsRenderingContext* aContext,
michael@0:                                   nsIFrame* aFrame,
michael@0:                                   uint8_t aWidgetType,
michael@0:                                   nsIntSize* aResult,
michael@0:                                   bool* aIsOverridable)=0;
michael@0: 
michael@0: 
michael@0:   enum Transparency {
michael@0:     eOpaque = 0,
michael@0:     eTransparent,
michael@0:     eUnknownTransparency
michael@0:   };
michael@0: 
michael@0:   /**
michael@0:    * Returns what we know about the transparency of the widget.
michael@0:    */
michael@0:   virtual Transparency GetWidgetTransparency(nsIFrame* aFrame, uint8_t aWidgetType)
michael@0:   { return eUnknownTransparency; }
michael@0: 
michael@0:   NS_IMETHOD WidgetStateChanged(nsIFrame* aFrame, uint8_t aWidgetType, 
michael@0:                                 nsIAtom* aAttribute, bool* aShouldRepaint)=0;
michael@0: 
michael@0:   NS_IMETHOD ThemeChanged()=0;
michael@0: 
michael@0:   virtual bool WidgetAppearanceDependsOnWindowFocus(uint8_t aWidgetType)
michael@0:   { return false; }
michael@0: 
michael@0:   /**
michael@0:    * Can the nsITheme implementation handle this widget?
michael@0:    */
michael@0:   virtual bool ThemeSupportsWidget(nsPresContext* aPresContext,
michael@0:                                      nsIFrame* aFrame,
michael@0:                                      uint8_t aWidgetType)=0;
michael@0: 
michael@0:   virtual bool WidgetIsContainer(uint8_t aWidgetType)=0;
michael@0: 
michael@0:   /**
michael@0:    * Does the nsITheme implementation draw its own focus ring for this widget?
michael@0:    */
michael@0:   virtual bool ThemeDrawsFocusForWidget(uint8_t aWidgetType)=0;
michael@0:   
michael@0:   /**
michael@0:     * Should we insert a dropmarker inside of combobox button?
michael@0:    */
michael@0:   virtual bool ThemeNeedsComboboxDropmarker()=0;
michael@0: 
michael@0:   /**
michael@0:    * Should we hide scrollbars?
michael@0:    */
michael@0:   virtual bool ShouldHideScrollbars()
michael@0:   { return false; }
michael@0: };
michael@0: 
michael@0: NS_DEFINE_STATIC_IID_ACCESSOR(nsITheme, NS_ITHEME_IID)
michael@0: 
michael@0: // Creator function
michael@0: extern nsresult NS_NewNativeTheme(nsISupports *aOuter, REFNSIID aIID, void **aResult);
michael@0: 
michael@0: #endif