gecko-dev/modules/libimg/public/ilIImageRenderer.h
1999-01-14 05:12:30 +00:00

159 lines
6.6 KiB
C++

/* -*- Mode: C; tab-width: 4; 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 ilIImageRenderer_h___
#define ilIImageRenderer_h___
#include <stdio.h>
#include "libimg.h"
#include "nsISupports.h"
// IID for the nsIImageRenderer interface
#define IL_IIMAGERENDERER_IID \
{ 0xec4e9fc0, 0xb1f3, 0x11d1, \
{ 0x9b, 0xc3, 0x00, 0x60, 0x08, 0x8c, 0xa6, 0xb3 } }
/**
* Interface to be implemented by image creation and rendering
* component plugged into the image library.
*/
class ilIImageRenderer : public nsISupports {
public:
/**
* This is the function invoked for allocating pixmap storage and
* platform-specific pixmap resources.
*
* On entry, the native color space and the original dimensions of the
* source image and its mask are initially filled in the two provided
* IL_Pixmap arguments. (If no mask or alpha channel is present, the
* second pixmap is NULL.)
*
* The width and height arguments represent the desired dimensions of the
* target image. If the implementation supports scaling, then the
* storage allocated for the IL_Pixmaps may be based on the original
* dimensions of the source image. In this case, the headers of the
* IL_Pixmap should not be modified, however, the implementation
* should be able to determine the target dimensions of the image for
* a given IL_Pixmap. (The opaque client_data pointer in the IL_Pixmap
* structure can be used to store the target image dimensions or a scale
* factor.)
*
* If the implementation does not support scaling, the supplied width
* and height must be used as the dimensions of the created pixmap storage
* and the headers within the IL_Pixmap should be side-effected to reflect
* that change.
*
* The allocator may side-effect the image and mask headers to target
* a different colorspace.
*
* The allocation function should side-effect bits, a member of the
* IL_Pixmap structure, to point to allocated storage. If there are
* insufficient resources to allocate both the image and mask, neither
* should be allocated. (The bits pointers, initially NULL-valued,
* should not be altered.)
*/
virtual void NewPixmap(void* aDisplayContext,
PRInt32 aWidth, PRInt32 aHeight,
IL_Pixmap* aImage, IL_Pixmap* aMask)=0;
/**
* Inform the implementation that the specified rectangular portion of
* the pixmap has been modified. This might be used, for example, to
* transfer the altered area to the X server on a unix client.
*
* x_offset and y_offset are measured in pixels, with the
* upper-left-hand corner of the pixmap as the origin, increasing
* left-to-right, top-to-bottom.
*/
virtual void UpdatePixmap(void* aDisplayContext,
IL_Pixmap* aImage,
PRInt32 aXOffset, PRInt32 aYOffset,
PRInt32 aWidth, PRInt32 aHeight)=0;
/**
* Informs the callee that the imagelib has acquired or relinquished
* control over the IL_Pixmap's bits. The message argument should be
* one of IL_LOCK_BITS, IL_UNLOCK_BITS or IL_RELEASE_BITS.
*
* The imagelib will issue an IL_LOCK_BITS message whenever it wishes to
* alter the bits. When the imaglib has finished altering the bits, it will
* issue an IL_UNLOCK_BITS message. These messages are provided so that
* the callee may perform memory-management tasks during the time that
* the imagelib is not writing to the pixmap's buffer.
*
* Once the imagelib is sure that it will not modify the pixmap any further
* and, therefore, will no longer dereference the bits pointer in the
* IL_Pixmap, it will issue an IL_RELEASE_BITS request. (Requests may still
* be made to display the pixmap, however, using whatever opaque pixmap
* storage the callee may retain.) The IL_RELEASE_BITS message
* could be used, for example, by an X11 front-end to free the client-side
* image data, preserving only the server pixmap.
*/
virtual void ControlPixmapBits(void* aDisplayContext,
IL_Pixmap* aImage, PRUint32 aControlMsg)=0;
/**
* Release the memory storage and other resources associated with an image
* pixmap; the pixmap will never be referenced again. The pixmap's header
* information and the IL_Pixmap structure itself will be freed by the Image
* Library.
*/
virtual void DestroyPixmap(void* aDisplayContext, IL_Pixmap* aImage)=0;
/**
* Render a rectangular portion of the given pixmap.
*
* Render the image using transparency if mask is non-NULL.
* x and y are measured in pixels and are in document coordinates.
* x_offset and y_offset are with respect to the image origin.
*
* If the width and height values would otherwise cause the sub-image
* to extend off the edge of the source image, the function should
* perform tiling of the source image. This is used to draw document,
* layer and table cell backdrops. (Note: it is assumed this case will
* apply only to images which do not require any scaling.)
*
* All coordinates are in terms of the target pixmap dimensions, which
* may differ from those of the pixmap storage if the callee
* supports scaling.
*/
virtual void DisplayPixmap(void* aDisplayContext,
IL_Pixmap* aImage, IL_Pixmap* aMask,
PRInt32 aX, PRInt32 aY,
PRInt32 aXOffset, PRInt32 aYOffset,
PRInt32 aWidth, PRInt32 aHeight)=0;
/**
* <bold>(Probably temporary and subject to change).</bold>
* Display an icon. x and y are in document coordinates.
*/
virtual void DisplayIcon(void* aDisplayContext,
PRInt32 aX, PRInt32 aY, PRUint32 aIconNumber)=0;
/**
* <bold>(Probably temporary and subject to change).</bold>
* This method should fill in the targets of the width and
* height pointers to indicate icon dimensions
*/
virtual void GetIconDimensions(void* aDisplayContext,
PRInt32 *aWidthPtr, PRInt32 *aHeightPtr,
PRUint32 aIconNumber)=0;
};
#endif