nsITheme.h
/* -*- 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;
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 \
{ 0xb0f3efe9, 0x0bd4, 0x4f6b, { 0x8d, 0xaa, 0x0e, 0xc7, 0xf6, 0x00, 0x68, 0x22 } }
// {D930E29B-6909-44e5-AB4B-AF10D6923705}
#define NS_THEMERENDERER_CID \
{ 0xd930e29b, 0x6909, 0x44e5, { 0xab, 0x4b, 0xaf, 0x10, 0xd6, 0x92, 0x37, 0x5 } }
enum nsTransparencyMode {
eTransparencyOpaque = 0, // Fully opaque
eTransparencyTransparent, // Parts of the window may be transparent
eTransparencyGlass, // Transparent parts of the window have Vista AeroGlass effect applied
eTransparencyBorderlessGlass // As above, but without a border around the opaque areas when there would otherwise be one with eTransparencyGlass
};
/**
* 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;
/**
* 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(nsPresContext* aPresContext,
nsIFrame* aFrame,
uint8_t aWidgetType)=0;
/**
* Should we insert a dropmarker inside of combobox button?
*/
virtual bool ThemeNeedsComboboxDropmarker()=0;
};
NS_DEFINE_STATIC_IID_ACCESSOR(nsITheme, NS_ITHEME_IID)
// Creator function
extern nsresult NS_NewNativeTheme(nsISupports *aOuter, REFNSIID aIID, void **aResult);
#endif