go-fitz/include/mupdf/helpers/mu-office-lib.h
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// Copyright (C) 2004-2021 Artifex Software, Inc.
//
// This file is part of MuPDF.
//
// MuPDF is free software: you can redistribute it and/or modify it under the
// terms of the GNU Affero General Public License as published by the Free
// Software Foundation, either version 3 of the License, or (at your option)
// any later version.
//
// MuPDF is distributed in the hope that it will be useful, but WITHOUT ANY
// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
// FOR A PARTICULAR PURPOSE. See the GNU Affero General Public License for more
// details.
//
// You should have received a copy of the GNU Affero General Public License
// along with MuPDF. If not, see <https://www.gnu.org/licenses/agpl-3.0.en.html>
//
// Alternative licensing terms are available from the licensor.
// For commercial licensing, see <https://www.artifex.com/> or contact
// Artifex Software, Inc., 39 Mesa Street, Suite 108A, San Francisco,
// CA 94129, USA, for further information.
/**
* Mu Office Library
*
* This helper layer provides an API for loading, and displaying
* a file. It is deliberately as identical as possible to the
* smart-office-lib.h header file in Smart Office to facilitate
* a product which can use both Smart Office and MuPDF.
*/
#ifndef MU_OFFICE_LIB_H
#define MU_OFFICE_LIB_H
/*
* General use
*
* This library uses threads but is not thread safe for the caller. All
* calls should be made from a single thread. Some calls allow the user
* to arrange for their own functions to be called back from the library;
* often the users functions will be called back from a different thread. If
* a call into the library is required in response to information from a
* callback, it is the responsibility of the user to arrange for those
* library calls to be made on the same thread as for other library calls.
* Calls back into the library from a callback are not permitted.
*
* There are two main modes of use. In interactive windowing systems, it
* is usual for the app developers code to be called on the main UI thread.
* It is from the UI thread that all library calls should be made. Such
* systems usually provide a way to post a call onto the UI thread. That
* is the best way to respond to a callback from the library.
*
* The other mode of use is for plain executables that might wish to
* (say) generate images of all the pages of a document. This can
* be achieved, without use of callbacks, using the few synchronous
* calls. E.g., MuOfficeDoc_getNumPages will wait for background document
* loading to complete before returning the total number of pages and
* MuOfficeRender_destroy will wait for background rendering to complete
* before returning.
*/
#include <stddef.h> /* For size_t */
#include "mupdf/fitz.h" /* For fz_context/fz_document/fz_page */
/** Error type returned from most MuOffice functions
*
* 0 means no error
*
* non-zero values mean an error occurred. The exact value is an indication
* of what went wrong and should be included in bug reports or support
* queries. Library users should not test this value except for 0,
* non-zero and any explicitly documented values.
*/
typedef int MuError;
/** Errors returned to MuOfficeLoadingErrorFn
*
* Other values may also be returned.
*/
typedef enum MuOfficeDocErrorType
{
MuOfficeDocErrorType_NoError = 0,
MuOfficeDocErrorType_UnsupportedDocumentType = 1,
MuOfficeDocErrorType_EmptyDocument = 2,
MuOfficeDocErrorType_UnableToLoadDocument = 4,
MuOfficeDocErrorType_UnsupportedEncryption = 5,
MuOfficeDocErrorType_Aborted = 6,
MuOfficeDocErrorType_OutOfMemory = 7,
/* FIXME: Additional ones that should be backported to
* smart-office-lib.h */
MuOfficeDocErrorType_IllegalArgument = 8,
/** A password is required to open this document.
*
* The app should provide it using MuOffice_providePassword
* or if it doesn't want to proceed call MuOfficeDoc_destroy or
* MuOfficeDoc_abortLoad.
*/
MuOfficeDocErrorType_PasswordRequest = 0x1000
} MuOfficeDocErrorType;
/**
*Structure holding the detail of the layout of a bitmap. b5g6r5 is assumed.
*/
typedef struct
{
void *memptr;
int width;
int height;
int lineSkip;
} MuOfficeBitmap;
/**
* Structure defining a point
*
* x x coord of point
* y y coord of point
*/
typedef struct
{
float x;
float y;
} MuOfficePoint;
/**
* Structure defining a rectangle
*
* x x coord of top left of area within the page
* y y coord of top left of area within the page
* width width of area
* height height of area
*/
typedef struct
{
float x;
float y;
float width;
float height;
} MuOfficeBox;
typedef enum MuOfficePointType
{
MuOfficePointType_MoveTo,
MuOfficePointType_LineTo
} MuOfficePointType;
typedef struct
{
float x;
float y;
MuOfficePointType type;
} MuOfficePathPoint;
/**
* Structure defining what area of a page should be rendered and to what
* area of the bitmap
*
* origin coordinates of the document origin within the bitmap
* renderArea the part of the bitmap to which to render
*/
typedef struct
{
MuOfficePoint origin;
MuOfficeBox renderArea;
} MuOfficeRenderArea;
typedef struct MuOfficeLib MuOfficeLib;
typedef struct MuOfficeDoc MuOfficeDoc;
typedef struct MuOfficePage MuOfficePage;
typedef struct MuOfficeRender MuOfficeRender;
/**
* Allocator function used by some functions to get blocks of memory.
*
* @param cookie data pointer passed in with the allocator.
* @param size the size of the required block.
*
* @returns as for malloc. (NULL implies OutOfMemory, or size == 0).
* Otherwise a pointer to an allocated block.
*/
typedef void *(MuOfficeAllocFn)(void *cookie,
size_t size);
/**
* Callback function monitoring document loading
*
* Also called when the document is edited, either adding or
* removing pages, with the pagesLoaded value decreasing
* in the page-removal case.
*
* @param cookie the data pointer that was originally passed
* to MuOfficeLib_loadDocument.
* @param pagesLoaded the number of pages so far discovered.
* @param complete whether loading has completed. If this flag
* is set, pagesLoaded is the actual number of
* pages in the document.
*/
typedef void (MuOfficeLoadingProgressFn)(void *cookie,
int pagesLoaded,
int complete);
/**
* Callback function used to monitor errors in the process of loading
* a document.
*
* @param cookie the data pointer that was originally passed
* to MuOfficeLib_loadDocument.
* @param error the error being reported
*/
typedef void (MuOfficeLoadingErrorFn)( void *cookie,
MuOfficeDocErrorType error);
/**
* Callback function used to monitor page changes
*
* @param cookie the data pointer that was originally passed
* to MuOfficeDoc_getPage.
* @param area the area that has changed.
*/
typedef void (MuOfficePageUpdateFn)( void *cookie,
const MuOfficeBox *area);
/**
* Callback function used to monitor a background render of a
* document page. The function is called exactly once.
*
* @param cookie the data pointer that was originally passed
* to MuOfficeDoc_monitorRenderProgress.
* @param error error returned from the rendering process
*/
typedef void (MuOfficeRenderProgressFn)(void *cookie,
MuError error);
/**
* Document types
*
* Keep in sync with smart-office-lib.h
*/
typedef enum
{
MuOfficeDocType_PDF,
MuOfficeDocType_XPS,
MuOfficeDocType_IMG
} MuOfficeDocType;
/**
* The possible results of a save operation
*/
typedef enum MuOfficeSaveResult
{
MuOfficeSave_Succeeded,
MuOfficeSave_Error,
MuOfficeSave_Cancelled
}
MuOfficeSaveResult;
/**
* Callback function used to monitor save operations.
*
* @param cookie the data pointer that was originally passed to
* MuOfficeDoc_save.
* @param result the result of the save operation
*/
typedef void (MuOfficeSaveResultFn)( void *cookie,
MuOfficeSaveResult result);
/**
* Create a MuOfficeLib instance.
*
* @param pMu address of variable to
* receive the created instance
*
* @return error indication - 0 for success
*/
MuError MuOfficeLib_create(MuOfficeLib **pMu);
/**
* Destroy a MuOfficeLib instance
*
* @param mu the instance to destroy
*/
void MuOfficeLib_destroy(MuOfficeLib *mu);
/**
* Find the type of a file given its filename extension.
*
* @param path path to the file (in utf8)
*
* @return a valid MuOfficeDocType value, or MuOfficeDocType_Other
*/
MuOfficeDocType MuOfficeLib_getDocTypeFromFileExtension(const char *path);
/**
* Return a list of filename extensions supported by Mu Office library.
*
* @return comma-delimited list of extensions, without the leading ".".
* The caller should free the returned pointer..
*/
char * MuOfficeLib_getSupportedFileExtensions(void);
/**
* Load a document
*
* Call will return immediately, leaving the document loading
* in the background
*
* @param mu a MuOfficeLib instance
* @param path path to the file to load (in utf8)
* @param progressFn callback for monitoring progress
* @param errorFn callback for monitoring errors
* @param cookie a pointer to pass back to the callbacks
* @param pDoc address for return of a MuOfficeDoc object
*
* @return error indication - 0 for success
*
* The progress callback may be called several times, with increasing
* values of pagesLoaded. Unless MuOfficeDoc_destroy is called,
* before loading completes, a call with "completed" set to true
* is guaranteed.
*
* Once MuOfficeDoc_destroy is called there will be no
* further callbacks.
*
* Alternatively, in a synchronous context, MuOfficeDoc_getNumPages
* can be called to wait for loading to complete and return the total
* number of pages. In this mode of use, progressFn can be NULL. 
*/
MuError MuOfficeLib_loadDocument(MuOfficeLib *mu,
const char *path,
MuOfficeLoadingProgressFn *progressFn,
MuOfficeLoadingErrorFn *errorFn,
void *cookie,
MuOfficeDoc **pDoc);
/**
* Perform MuPDF native operations on a given MuOfficeLib
* instance.
*
* The function is called with a fz_context value that can
* be safely used (i.e. the context is cloned/dropped
* appropriately around the call). The function should signal
* errors by fz_throw-ing.
*
* @param mu the MuOfficeLib instance.
* @param fn the function to call to run the operations.
* @param arg Opaque data pointer.
*
* @return error indication - 0 for success
*/
MuError MuOfficeLib_run(MuOfficeLib *mu, void (*fn)(fz_context *ctx, void *arg), void *arg);
/**
* Provide the password for a document
*
* This function should be called to provide a password with a document
* error if MuOfficeError_PasswordRequired is received.
*
* If a password is requested again, this means the password was incorrect.
*
* @param doc the document object
* @param password the password (UTF8 encoded)
* @return error indication - 0 for success
*/
int MuOfficeDoc_providePassword(MuOfficeDoc *doc, const char *password);
/**
* Return the type of an open document
*
* @param doc the document object
*
* @return the document type
*/
MuOfficeDocType MuOfficeDoc_docType(MuOfficeDoc *doc);
/**
* Return the number of pages of a document
*
* This function waits for document loading to complete before returning
* the result. It may block the calling thread for a significant period of
* time. To avoid blocking, this call should be avoided in favour of using
* the MuOfficeLib_loadDocument callbacks to monitor loading.
*
* If background loading fails, the associated error will be returned
* from this call.
*
* @param doc the document
* @param pNumPages address for return of the number of pages
*
* @return error indication - 0 for success
*/
MuError MuOfficeDoc_getNumPages(MuOfficeDoc *doc, int *pNumPages);
/**
* Determine if the document has been modified
*
* @param doc the document
*
* @return modified flag
*/
int MuOfficeDoc_hasBeenModified(MuOfficeDoc *doc);
/**
* Start a save operation
*
* @param doc the document
* @param path path of the file to which to save
* @param resultFn callback used to report completion
* @param cookie a pointer to pass to the callback
*
* @return error indication - 0 for success
*/
MuError MuOfficeDoc_save(MuOfficeDoc *doc,
const char *path,
MuOfficeSaveResultFn *resultFn,
void *cookie);
/**
* Stop a document loading. The document is not destroyed, but
* no further content will be read from the file.
*
* @param doc the MuOfficeDoc object
*/
void MuOfficeDoc_abortLoad(MuOfficeDoc *doc);
/**
* Destroy a MuOfficeDoc object. Loading of the document is shutdown
* and no further callbacks will be issued for the specified object.
*
* @param doc the MuOfficeDoc object
*/
void MuOfficeDoc_destroy(MuOfficeDoc *doc);
/**
* Get a page of a document
*
* @param doc the document object
* @param pageNumber the number of the page to load (lying in the
* range 0 to one less than the number of pages)
* @param updateFn Function to be called back when the page updates
* @param cookie Opaque value to pass for any updates
* @param pPage Address for return of the page object
*
* @return error indication - 0 for success
*/
MuError MuOfficeDoc_getPage( MuOfficeDoc *doc,
int pageNumber,
MuOfficePageUpdateFn *updateFn,
void *cookie,
MuOfficePage **pPage);
/**
* Perform MuPDF native operations on a given document.
*
* The function is called with fz_context and fz_document
* values that can be safely used (i.e. the context is
* cloned/dropped appropriately around the function, and
* locking is used to ensure that no other threads are
* simultaneously using the document). Functions can
* signal errors by fz_throw-ing.
*
* Due to the locking, it is best to ensure that as little
* time is taken here as possible (i.e. if you fetch some
* data and then spend a long time processing it, it is
* probably best to fetch the data using MuOfficeDoc_run
* and then process it outside). This avoids potentially
* blocking the UI.
*
* @param doc the document object.
* @param fn the function to call with fz_context/fz_document
* values.
* @param arg Opaque data pointer.
*
* @return error indication - 0 for success
*/
MuError MuOfficeDoc_run(MuOfficeDoc *doc, void (*fn)(fz_context *ctx, fz_document *doc, void *arg), void *arg);
/**
* Destroy a page object
*
* Note this does not delete or remove the page from the document.
* It simply destroys the page object which is merely a reference
* to the page.
*
* @param page the page object
*/
void MuOfficePage_destroy(MuOfficePage *page);
/**
* Get the size of a page in pixels
*
* This returns the size of the page in pixels. Pages can be rendered
* with a zoom factor. The returned value is the size of bitmap
* appropriate for rendering with a zoom of 1.0 and corresponds to
* 90 dpi. The returned values are not necessarily whole numbers.
*
* @param page the page object
* @param pWidth address for return of the width
* @param pHeight address for return of the height
*
* @return error indication - 0 for success
*/
MuError MuOfficePage_getSize( MuOfficePage *page,
float *pWidth,
float *pHeight);
/**
* Return the zoom factors necessary to render at to a given
* size in pixels. (deprecated)
*
* @param page the page object
* @param width the desired width
* @param height the desired height
* @param pXZoom Address for return of zoom necessary to fit width
* @param pYZoom Address for return of zoom necessary to fit height
*
* @return error indication - 0 for success
*/
MuError MuOfficePage_calculateZoom( MuOfficePage *page,
int width,
int height,
float *pXZoom,
float *pYZoom);
/**
* Get the size of a page in pixels for a specified zoom factor
* (deprecated)
*
* This returns the size of bitmap that should be used to display
* the entire page at the given zoom factor. A zoom of 1.0
* corresponds to 90 dpi.
*
* @param page the page object
* @param zoom the zoom factor
* @param pWidth address for return of the width
* @param pHeight address for return of the height
*
* @return error indication - 0 for success
*/
MuError MuOfficePage_getSizeForZoom( MuOfficePage *page,
float zoom,
int *pWidth,
int *pHeight);
/**
* Perform MuPDF native operations on a given page.
*
* The function is called with fz_context and fz_page
* values that can be safely used (i.e. the context is
* cloned/dropped appropriately around the function, and
* locking is used to ensure that no other threads are
* simultaneously using the document). Functions can
* signal errors by fz_throw-ing.
*
* Due to the locking, it is best to ensure that as little
* time is taken here as possible (i.e. if you fetch some
* data and then spend a long time processing it, it is
* probably best to fetch the data using MuOfficePage_run
* and then process it outside). This avoids potentially
* blocking the UI.
*
* @param page the page object.
* @param fn the function to call with fz_context/fz_document
* values.
* @param arg Opaque data pointer.
*
* @return error indication - 0 for success
*/
MuError MuOfficePage_run(MuOfficePage *page, void (*fn)(fz_context *ctx, fz_page *page, void *arg), void *arg);
/**
* Schedule the rendering of an area of document page to
* an area of a bitmap.
*
* The alignment between page and bitmap is defined by specifying
* document's origin within the bitmap, possibly either positive or
* negative. A render object is returned via which the process can
* be monitored or terminated.
*
* The progress function is called exactly once per render in either
* the success or failure case.
*
* Note that, since a render object represents a running thread that
* needs access to the page, document, and library objects, it is important
* to call MuOfficeRender_destroy, not only before using or deallocating
* the bitmap, but also before calling MuOfficePage_destroy, etc..
*
* @param page the page to render
* @param zoom the zoom factor
* @param bitmap the bitmap
* @param area area to render
* @param progressFn the progress callback function
* @param cookie a pointer to pass to the callback function
* @param pRender Address for return of the render object
*
* @return error indication - 0 for success
*/
MuError MuOfficePage_render( MuOfficePage *page,
float zoom,
const MuOfficeBitmap *bitmap,
const MuOfficeRenderArea *area,
MuOfficeRenderProgressFn *progressFn,
void *cookie,
MuOfficeRender **pRender);
/**
* Destroy a render
*
* This call destroys a MuOfficeRender object, aborting any current
* render.
*
* This call is intended to support an app dealing with a user quickly
* flicking through document pages. A render may be scheduled but, before
* completion, be found not to be needed. In that case the bitmap will
* need to be reused, which requires any existing render to be aborted.
* The call to MuOfficeRender_destroy will cut short the render and
* allow the bitmap to be reused immediately.
*
* @note If an active render thread is destroyed, it will be aborted.
* While fast, this is not an instant operation. For maximum
* responsiveness, it is best to 'abort' as soon as you realise you
* don't need the render, and to destroy when you get the callback.
*
* @param render The render object
*/
void MuOfficeRender_destroy(MuOfficeRender *render);
/**
* Abort a render
*
* This call aborts any rendering currently underway. The 'render
* complete' callback (if any) given when the render was created will
* still be called. If a render has completed, this call will have no
* effect.
*
* This call will not block to wait for the render thread to stop, but
* will cause it to stop as soon as it can in the background.
*
* @note It is important not to start any new render to the same bitmap
* until the callback comes in (or until waitUntilComplete returns), as
* otherwise you can have multiple renders drawing to the same bitmap
* with unpredictable consequences.
*
* @param render The render object to abort
*/
void MuOfficeRender_abort(MuOfficeRender *render);
/**
* Wait for a render to complete.
*
* This call will not return until rendering is complete, so on return
* the bitmap will contain the page image (assuming the render didn't
* run into an error condition) and will not be used further by any
* background processing. Any error during rendering will be returned
* from this function.
*
* This call may block the calling thread for a significant period of
* time. To avoid blocking, supply a progress-monitoring callback
* function to MuOfficePage_render.
*
* @param render The render object to destroy
* @return render error condition - 0 for no error.
*/
MuError MuOfficeRender_waitUntilComplete(MuOfficeRender *render);
#endif /* SMART_OFFICE_LIB_H */