pjs/layout/base/nsPresContext.h

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/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
*
* The contents of this file are subject to the Netscape Public License
* Version 1.0 (the "NPL"); you may not use this file except in
* compliance with the NPL. You may obtain a copy of the NPL at
* http://www.mozilla.org/NPL/
*
* Software distributed under the NPL is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
* for the specific language governing rights and limitations under the
* NPL.
*
* The Initial Developer of this code under the NPL is Netscape
* Communications Corporation. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All Rights
* Reserved.
*/
#ifndef nsIPresContext_h___
#define nsIPresContext_h___
#include "nslayout.h"
#include "nsISupports.h"
#include "nsRect.h"
struct nsFont;
class nsIContent;
class nsIDeviceContext;
class nsIFontMetrics;
class nsIFrame;
class nsIFrameImageLoader;
class nsIImageGroup;
class nsILinkHandler;
class nsIPresShell;
class nsIStyleContext;
class nsIAtom;
class nsString;
#define NS_IPRESCONTEXT_IID \
{ 0x0a5d12e0, 0x944e, 0x11d1, \
{0x93, 0x23, 0x00, 0x80, 0x5f, 0x8a, 0xdd, 0x32} }
// An interface for presentation contexts. Presentation contexts are
// objects that provide an outer context for a presentation shell.
class nsIPresContext : public nsISupports {
public:
/**
* Set the presentation shell that this context is bound to.
* A presentation context may only be bound to a single shell.
*/
virtual void SetShell(nsIPresShell* aShell) = 0;
/**
* Get the PresentationShell that this context is bound to.
*/
virtual nsIPresShell* GetShell() = 0;
/**
* Resolve style for the given piece of content that will be a child
* of the aParentFrame frame. Don't use this for pseudo frames.
*/
virtual nsIStyleContext* ResolveStyleContextFor(nsIContent* aContent,
nsIFrame* aParentFrame) = 0;
/**
* Resolve style for a pseudo frame within the given aParentFrame frame.
* The tag should be uppercase and inclue the colon.
* ie: NS_NewAtom(":FIRST-LINE");
*/
virtual nsIStyleContext* ResolvePseudoStyleContextFor(nsIAtom* aPseudoTag,
nsIFrame* aParentFrame) = 0;
/**
* Probe style for a pseudo frame within the given aParentFrame frame.
* This will return nsnull id there are no explicit rules for the pseudo element.
* The tag should be uppercase and inclue the colon.
* ie: NS_NewAtom(":FIRST-LINE");
*/
virtual nsIStyleContext* ProbePseudoStyleContextFor(nsIAtom* aPseudoTag,
nsIFrame* aParentFrame) = 0;
/**
* Get the font metrics for a given font.
*/
virtual nsIFontMetrics* GetMetricsFor(const nsFont& aFont) = 0;
/**
* Get the default font
*/
virtual const nsFont& GetDefaultFont(void) = 0;
NS_IMETHOD GetImageGroup(nsIImageGroup*& aGroupResult) = 0;
/**
* Load an image for the target frame. This call can be made
* repeated with only a single image every being loaded. If
* aNeedSizeUpdate is PR_TRUE then when the image's size is
* determined the target frame will be reflowed (via a
* ContentChanged notification on the presentation shell). When the
* image's data is ready for rendering the target frames Paint
* method will be invoked (via the ViewManager so that the
* appropriate damage repair is done).
*/
NS_IMETHOD LoadImage(const nsString& aURL,
nsIFrame* aTargetFrame,
PRBool aNeedSizeUpdate,
nsIFrameImageLoader*& aLoader) = 0;
/**
* Stop any image loading being done on behalf of the argument frame.
*/
NS_IMETHOD StopLoadImage(nsIFrame* aForFrame) = 0;
NS_IMETHOD SetContainer(nsISupports* aContainer) = 0;
NS_IMETHOD GetContainer(nsISupports** aResult) = 0;
NS_IMETHOD SetLinkHandler(nsILinkHandler* aHandler) = 0;
NS_IMETHOD GetLinkHandler(nsILinkHandler** aResult) = 0;
/**
* Get the currently visible portion of the RootContent ILayoutable.
* The units returned are in pixels. An acceptable answer is "null"
* which means "I don't know".
* <h2>Speculative</h2>
*/
virtual nsRect GetVisibleArea() = 0;
/**
* Set the currently visible area. This is the size and location
* of the visible portion of the RootContent ILayoutable.
*/
virtual void SetVisibleArea(const nsRect& r) = 0;
/**
* Return true if this presentation context is a paginated
* context.
*/
virtual PRBool IsPaginated() = 0;
/**
* Return the page width if this is a paginated context.
*/
virtual nscoord GetPageWidth() = 0;
/**
* Return the page height if this is a paginated context
*/
virtual nscoord GetPageHeight() = 0;
virtual float GetPixelsToTwips() const = 0;
virtual float GetTwipsToPixels() const = 0;
//be sure to Relase() after you are done with the Get()
virtual nsIDeviceContext * GetDeviceContext() const = 0;
};
// Bit values for LoadImage's aImageStatus
#define NS_LOAD_IMAGE_STATUS_ERROR 0x1
#define NS_LOAD_IMAGE_STATUS_SIZE 0x2
#define NS_LOAD_IMAGE_STATUS_BITS 0x4
// Factory method to create a "galley" presentation context (galley is
// a kind of view that has no limit to the size of a page)
extern NS_LAYOUT nsresult
NS_NewGalleyContext(nsIPresContext** aInstancePtrResult);
// Factory method to create a "paginated" presentation context for
// the screen.
extern NS_LAYOUT nsresult
NS_NewPrintPreviewContext(nsIPresContext** aInstancePtrResult);
#endif /* nsIPresContext_h___ */