--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mupdf-source/source/helpers/mu-office-lib/mu-office-lib.c	Mon Sep 15 11:43:07 2025 +0200
@@ -0,0 +1,1234 @@
+// Copyright (C) 2004-2025 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
+ *
+ * Provided access to the core document, loading, displaying and
+ * editing routines
+ *
+ * Intended for use with native UI
+ */
+
+#include "mupdf/fitz.h"
+#include "mupdf/pdf.h"
+#include "mupdf/helpers/mu-office-lib.h"
+#include "mupdf/helpers/mu-threads.h"
+#include "mupdf/memento.h"
+
+#include <assert.h>
+
+enum
+{
+	MuError_OK = 0,
+	MuError_OOM = -1,
+	MuError_BadNull = -2,
+	MuError_Generic = -3,
+	MuError_NotImplemented = -4,
+	MuError_PasswordPending = -5,
+};
+
+enum {
+	LAYOUT_W = 450,
+	LAYOUT_H = 600,
+	LAYOUT_EM = 12
+};
+
+#ifdef DISABLE_MUTHREADS
+#error "mu-office-lib requires threading to be enabled"
+#endif
+
+/*
+	If we are building as part of a smartoffice build, then we
+	should appeal to Pal_Mem_etc to get memory. If not, then
+	we should use malloc instead.
+
+	FIXME: Allow for something other than malloc/calloc/realloc/
+	free here.
+*/
+#ifndef SMARTOFFICE_BUILD
+void *Pal_Mem_calloc(unsigned int num, size_t size)
+{
+	return calloc(num, size);
+}
+
+void *Pal_Mem_malloc(size_t size)
+{
+	return malloc(size);
+}
+
+void *Pal_Mem_realloc(void *ptr, size_t size)
+{
+	return realloc(ptr, size);
+}
+
+void Pal_Mem_free(void *address)
+{
+	free(address);
+}
+#endif
+
+/*
+	All MuPDF's allocations are redirected through the
+	following functions.
+*/
+static void *muoffice_malloc(void *arg, size_t size)
+{
+	return Pal_Mem_malloc(size);
+}
+
+static void *muoffice_realloc(void *arg, void *old, size_t size)
+{
+	return Pal_Mem_realloc(old, size);
+}
+
+static void muoffice_free(void *arg, void *ptr)
+{
+	Pal_Mem_free(ptr);
+}
+
+static fz_alloc_context muoffice_alloc =
+{
+	/* user */
+	NULL,
+
+	/* void *(*malloc)(void *, size_t); */
+	muoffice_malloc,
+
+	/* void *(*realloc)(void *, void *, size_t); */
+	muoffice_realloc,
+
+	/* void (*free)(void *, void *); */
+	muoffice_free
+};
+
+/*
+	All MuPDF's locking is done using the following functions
+*/
+static void muoffice_lock(void *user, int lock);
+
+static void muoffice_unlock(void *user, int lock);
+
+struct MuOfficeLib
+{
+	fz_context *ctx;
+	mu_mutex mutexes[FZ_LOCK_MAX+1];
+	fz_locks_context locks;
+};
+
+/*
+	We add 1 extra lock which we use in this helper to protect
+	against accessing the fz_document from multiple threads
+	inadvertently when the caller is calling 'run' or
+	'runBackground'.
+*/
+enum
+{
+	DOCLOCK = FZ_LOCK_MAX
+};
+
+static void muoffice_lock(void *user, int lock)
+{
+	MuOfficeLib *mu = (MuOfficeLib *)user;
+
+	mu_lock_mutex(&mu->mutexes[lock]);
+}
+
+static void muoffice_unlock(void *user, int lock)
+{
+	MuOfficeLib *mu = (MuOfficeLib *)user;
+
+	mu_unlock_mutex(&mu->mutexes[lock]);
+}
+
+static void muoffice_doc_lock(MuOfficeLib *mu)
+{
+	mu_lock_mutex(&mu->mutexes[DOCLOCK]);
+}
+
+static void muoffice_doc_unlock(MuOfficeLib *mu)
+{
+	mu_unlock_mutex(&mu->mutexes[DOCLOCK]);
+}
+
+static void fin_muoffice_locks(MuOfficeLib *mu)
+{
+	int i;
+
+	for (i = 0; i < FZ_LOCK_MAX+1; i++)
+		mu_destroy_mutex(&mu->mutexes[i]);
+}
+
+static fz_locks_context *init_muoffice_locks(MuOfficeLib *mu)
+{
+	int i;
+	int failed = 0;
+
+	for (i = 0; i < FZ_LOCK_MAX+1; i++)
+		failed |= mu_create_mutex(&mu->mutexes[i]);
+
+	if (failed)
+	{
+		fin_muoffice_locks(mu);
+		return NULL;
+	}
+
+	mu->locks.user = mu;
+	mu->locks.lock = muoffice_lock;
+	mu->locks.unlock = muoffice_unlock;
+
+	return &mu->locks;
+}
+
+MuError MuOfficeLib_create(MuOfficeLib **pMu)
+{
+	MuOfficeLib *mu;
+	fz_locks_context *locks;
+
+	if (pMu == NULL)
+		return MuOfficeDocErrorType_IllegalArgument;
+
+	mu = Pal_Mem_calloc(1, sizeof(MuOfficeLib));
+	if (mu == NULL)
+		return MuOfficeDocErrorType_OutOfMemory;
+
+	locks = init_muoffice_locks(mu);
+	if (locks == NULL)
+		goto Fail;
+
+	mu->ctx = fz_new_context(&muoffice_alloc, locks, FZ_STORE_DEFAULT);
+	if (mu->ctx == NULL)
+		goto Fail;
+
+	fz_try(mu->ctx)
+		fz_register_document_handlers(mu->ctx);
+	fz_catch(mu->ctx)
+		goto Fail;
+
+	*pMu = mu;
+
+	return MuOfficeDocErrorType_NoError;
+
+Fail:
+	if (mu)
+	{
+		fin_muoffice_locks(mu);
+		Pal_Mem_free(mu);
+	}
+	return MuOfficeDocErrorType_OutOfMemory;
+}
+
+/**
+ * Destroy a MuOfficeLib instance
+ *
+ * @param mu  the instance to destroy
+ */
+void MuOfficeLib_destroy(MuOfficeLib *mu)
+{
+	if (mu == NULL)
+		return;
+
+	fz_drop_context(mu->ctx);
+	fin_muoffice_locks(mu);
+
+	Pal_Mem_free(mu);
+}
+
+/**
+ * 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)
+{
+	fz_context *ctx;
+	MuError err = MuError_OK;
+
+	if (mu == NULL)
+		return MuError_BadNull;
+	if (fn == NULL)
+		return err;
+
+	ctx = fz_clone_context(mu->ctx);
+	if (ctx == NULL)
+		return MuError_OOM;
+
+	fz_try(ctx)
+		fn(ctx, arg);
+	fz_catch(ctx)
+		err = MuError_Generic;
+
+	fz_drop_context(ctx);
+
+	return err;
+}
+
+/**
+ * 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 /* FIXME */MuOfficeDocType_PDF;
+}
+
+/**
+ * Return a list of file 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)
+{
+	/* FIXME */
+	return NULL;
+}
+
+struct MuOfficeDoc
+{
+	MuOfficeLib *mu;
+	fz_context *ctx;
+	MuOfficeLoadingProgressFn *progress;
+	MuOfficeLoadingErrorFn *error;
+	void *cookie;
+	char *path;
+	char *password;
+	mu_semaphore password_sem;
+	mu_thread thread;
+	int needs_password;
+	int aborted;
+	fz_document *doc;
+
+	MuOfficePage *pages;
+};
+
+struct MuOfficePage
+{
+	MuOfficePage *next;
+	MuOfficeDoc *doc;
+	int pageNum;
+	void *cookie;
+	MuOfficePageUpdateFn *updateFn;
+	fz_page *page;
+	fz_display_list *list;
+};
+
+struct MuOfficeRender
+{
+	MuOfficePage *page;
+	float zoom;
+	const MuOfficeBitmap *bitmap;
+	int area_valid;
+	MuOfficeRenderArea area;
+	MuOfficeRenderProgressFn *progress;
+	MuError error;
+	mu_thread thread;
+	void *cookie;
+	fz_cookie mu_cookie;
+};
+
+static void load_worker(void *arg)
+{
+	MuOfficeDoc *doc = (MuOfficeDoc *)arg;
+	int numPages = 0;
+	fz_context *ctx = fz_clone_context(doc->ctx);
+	int err = 0;
+
+	if (ctx == NULL)
+	{
+		return;
+	}
+
+	muoffice_doc_lock(doc->mu);
+
+	fz_try(ctx)
+	{
+		doc->doc = fz_open_document(ctx, doc->path);
+		doc->needs_password = fz_needs_password(ctx, doc->doc);
+	}
+	fz_catch(ctx)
+	{
+		err = MuOfficeDocErrorType_UnsupportedDocumentType;
+		goto fail;
+	}
+
+	fz_try(ctx)
+	{
+		if (doc->needs_password && doc->error)
+		{
+			do
+			{
+				doc->error(doc->cookie, MuOfficeDocErrorType_PasswordRequest);
+				mu_wait_semaphore(&doc->password_sem);
+				if (doc->aborted)
+					break;
+				doc->needs_password = (fz_authenticate_password(ctx, doc->doc, doc->password) != 0);
+				Pal_Mem_free(doc->password);
+				doc->password = NULL;
+			}
+			while (doc->needs_password);
+		}
+
+		fz_layout_document(ctx, doc->doc, LAYOUT_W, LAYOUT_H, LAYOUT_EM);
+
+		numPages = fz_count_pages(ctx, doc->doc);
+	}
+	fz_catch(ctx)
+		err = MuOfficeDocErrorType_UnableToLoadDocument;
+
+fail:
+	muoffice_doc_unlock(doc->mu);
+
+	if (err)
+		doc->error(doc->cookie, err);
+
+	if (doc->progress)
+		doc->progress(doc->cookie, numPages, 1);
+
+	fz_drop_context(ctx);
+}
+
+/**
+ * Load a document
+ *
+ * Call will return immediately, leaving the document loading
+ * in the background
+ *
+ * @param so         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)
+{
+	MuOfficeDoc *doc;
+	fz_context *ctx;
+
+	if (mu == NULL || pDoc == NULL)
+		return MuOfficeDocErrorType_IllegalArgument;
+
+	*pDoc = NULL;
+
+	doc = Pal_Mem_calloc(1, sizeof(*doc));
+	if (doc == NULL)
+		return MuOfficeDocErrorType_NoError;
+
+	ctx = mu->ctx;
+	doc->mu       = mu;
+	doc->ctx      = fz_clone_context(ctx);
+	doc->progress = progressFn;
+	doc->error    = errorFn;
+	doc->cookie   = cookie;
+	doc->path     = fz_strdup(ctx, path);
+	if (mu_create_semaphore(&doc->password_sem))
+		goto fail;
+
+	if (mu_create_thread(&doc->thread, load_worker, doc))
+		goto fail;
+
+	*pDoc = doc;
+
+	return MuError_OK;
+fail:
+	mu_destroy_semaphore(&doc->password_sem);
+	Pal_Mem_free(doc);
+
+	return MuError_OOM;
+}
+
+/**
+ * Provide the password for a document
+ *
+ * This function should be called to provide a password with a document
+ * error of 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)
+{
+	size_t len;
+
+	if (doc->password)
+		return MuError_PasswordPending;
+	if (!password)
+		password = "";
+
+	len = strlen(password);
+	doc->password = Pal_Mem_malloc(len+1);
+	strcpy(doc->password, password);
+	mu_trigger_semaphore(&doc->password_sem);
+
+	return MuError_OK;
+}
+
+/**
+ * Return the type of an open document
+ *
+ * @param doc         the document object
+ *
+ * @return            the document type
+ */
+MuOfficeDocType MuOfficeDoc_docType(MuOfficeDoc *doc)
+{
+	return /* FIXME */MuOfficeDocType_PDF;
+}
+
+static void
+ensure_doc_loaded(MuOfficeDoc *doc)
+{
+	if (doc == NULL)
+		return;
+
+	mu_destroy_thread(&doc->thread);
+}
+
+/**
+ * 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)
+{
+	fz_context *ctx;
+	MuError err = MuError_OK;
+
+	if (doc == NULL)
+	{
+		*pNumPages = 0;
+		return MuError_BadNull;
+	}
+
+	ensure_doc_loaded(doc);
+
+	ctx = doc->ctx;
+
+	fz_try(ctx)
+	{
+		*pNumPages = fz_count_pages(ctx, doc->doc);
+	}
+	fz_catch(ctx)
+	{
+		err = MuError_Generic;
+	}
+
+	return err;
+}
+
+/**
+ * Determine if the document has been modified
+ *
+ * @param doc         the document
+ *
+ * @return            modified flag
+ */
+int MuOfficeDoc_hasBeenModified(MuOfficeDoc *doc)
+{
+	fz_context *ctx;
+	pdf_document *pdoc;
+	int modified = 0;
+
+	if (doc == NULL)
+		return 0;
+
+	ensure_doc_loaded(doc);
+
+	ctx = doc->ctx;
+	pdoc = pdf_specifics(ctx, doc->doc);
+
+	if (pdoc == NULL)
+		return 0;
+
+	fz_try(ctx)
+		modified = pdf_has_unsaved_changes(ctx, pdoc);
+	fz_catch(ctx)
+		modified = 0;
+
+	return modified;
+}
+
+/**
+ * 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)
+{
+	return MuError_NotImplemented; /* FIXME */
+}
+
+/**
+ * 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)
+{
+	fz_context *ctx;
+
+	if (doc == NULL)
+		return;
+
+	ctx = doc->ctx;
+	doc->aborted = 1;
+	mu_trigger_semaphore(&doc->password_sem);
+}
+
+/**
+ * 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)
+{
+	MuOfficeDoc_abortLoad(doc);
+	mu_destroy_thread(&doc->thread);
+	mu_destroy_semaphore(&doc->password_sem);
+
+	fz_drop_document(doc->ctx, doc->doc);
+	fz_drop_context(doc->ctx);
+	Pal_Mem_free(doc->path);
+	Pal_Mem_free(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)
+{
+	MuOfficePage *page;
+	MuError err = MuError_OK;
+	fz_context *ctx;
+
+	if (!doc)
+		return MuError_BadNull;
+	if (!pPage)
+		return MuError_OK;
+
+	*pPage = NULL;
+
+	ensure_doc_loaded(doc);
+	ctx = doc->ctx;
+
+	page = Pal_Mem_calloc(1, sizeof(*page));
+	if (page == NULL)
+		return MuError_OOM;
+
+	muoffice_doc_lock(doc->mu);
+
+	fz_try(ctx)
+	{
+		page->doc = doc;
+		page->pageNum = pageNumber;
+		page->cookie = cookie;
+		page->updateFn = updateFn;
+		page->page = fz_load_page(doc->ctx, doc->doc, pageNumber);
+		page->next = doc->pages;
+		doc->pages = page;
+		*pPage = page;
+	}
+	fz_catch(ctx)
+	{
+		Pal_Mem_free(page);
+		err = MuError_Generic;
+	}
+
+	muoffice_doc_unlock(doc->mu);
+
+	return err;
+}
+
+/**
+ * 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)
+{
+	fz_context *ctx;
+	MuError err = MuError_OK;
+
+	if (doc == NULL)
+		return MuError_BadNull;
+	if (fn == NULL)
+		return err;
+
+	ensure_doc_loaded(doc);
+
+	ctx = fz_clone_context(doc->mu->ctx);
+	if (ctx == NULL)
+		return MuError_OOM;
+
+	muoffice_doc_lock(doc->mu);
+
+	fz_try(ctx)
+		fn(ctx, doc->doc, arg);
+	fz_catch(ctx)
+		err = MuError_Generic;
+
+	muoffice_doc_unlock(doc->mu);
+
+	fz_drop_context(ctx);
+
+	return err;
+}
+
+/**
+ * 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)
+{
+	MuOfficeDoc *doc;
+	MuOfficePage **ptr;
+
+	if (!page)
+		return;
+
+	/* Unlink page from doc */
+	doc = page->doc;
+	ptr = &doc->pages;
+	while (*ptr && *ptr != page)
+		ptr = &(*ptr)->next;
+	assert(*ptr);
+	*ptr = page->next;
+
+	fz_drop_page(doc->ctx, page->page);
+	fz_drop_display_list(doc->ctx, page->list);
+	fz_free(doc->ctx, 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)
+{
+	MuOfficeDoc *doc;
+	fz_rect rect;
+
+	if (!page)
+		return MuError_BadNull;
+	doc = page->doc;
+	if (!doc)
+		return MuError_BadNull;
+
+	rect = fz_bound_page(doc->ctx, page->page);
+
+	/* MuPDF measures in points (72ths of an inch). This API wants
+	 * 90ths of an inch, so adjust. */
+
+	if (pWidth)
+		*pWidth = 90 * (rect.x1 - rect.x0) / 72;
+	if (pHeight)
+		*pHeight = 90 * (rect.y1 - rect.y0) / 72;
+
+	return MuError_OK;
+}
+
+/**
+ * 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)
+{
+	MuOfficeDoc *doc;
+	fz_rect rect;
+	float w, h;
+
+	if (!page)
+		return MuError_BadNull;
+	doc = page->doc;
+	if (!doc)
+		return MuError_BadNull;
+
+	rect = fz_bound_page(doc->ctx, page->page);
+
+	/* MuPDF measures in points (72ths of an inch). This API wants
+	 * 90ths of an inch, so adjust. */
+	w = 90 * (rect.x1 - rect.x0) / 72;
+	h = 90 * (rect.y1 - rect.y0) / 72;
+
+	if (pXZoom)
+		*pXZoom = width/w;
+	if (pYZoom)
+		*pYZoom = height/h;
+
+	return MuError_OK;
+}
+
+/**
+ * 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)
+{
+	MuOfficeDoc *doc;
+	fz_rect rect;
+	float w, h;
+
+	if (!page)
+		return MuError_BadNull;
+	doc = page->doc;
+	if (!doc)
+		return MuError_BadNull;
+
+	rect = fz_bound_page(doc->ctx, page->page);
+
+	/* MuPDF measures in points (72ths of an inch). This API wants
+	 * 90ths of an inch, so adjust. */
+	w = 90 * (rect.x1 - rect.x0) / 72;
+	h = 90 * (rect.y1 - rect.y0) / 72;
+
+	if (pWidth)
+		*pWidth = (int)(w * zoom + 0.5f);
+	if (pHeight)
+		*pHeight = (int)(h * zoom + 0.5f);
+
+	return MuError_OK;
+}
+
+/**
+ * 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)
+{
+	fz_context *ctx;
+	MuError err = MuError_OK;
+
+	if (page == NULL)
+		return MuError_BadNull;
+	if (fn == NULL)
+		return err;
+
+	ctx = fz_clone_context(page->doc->mu->ctx);
+	if (ctx == NULL)
+		return MuError_OOM;
+
+	muoffice_doc_lock(page->doc->mu);
+
+	fz_try(ctx)
+		fn(ctx, page->page, arg);
+	fz_catch(ctx)
+		err = MuError_Generic;
+
+	muoffice_doc_unlock(page->doc->mu);
+
+	fz_drop_context(ctx);
+
+	return err;
+}
+
+static void render_worker(void *arg)
+{
+	MuOfficeRender *render = (MuOfficeRender *)arg;
+	MuOfficePage *page = render->page;
+	fz_context *ctx = fz_clone_context(page->doc->ctx);
+	int err = 0;
+	fz_pixmap *pixmap = NULL;
+	fz_device *dev = NULL;
+	float scalex;
+	float scaley;
+	fz_rect page_bounds;
+	int locked = 0;
+
+	if (ctx == NULL)
+		return;
+
+	fz_var(pixmap);
+	fz_var(dev);
+	fz_var(locked);
+
+	fz_try(ctx)
+	{
+		if (page->list == NULL)
+		{
+			muoffice_doc_lock(page->doc->mu);
+			locked = 1;
+			page->list = fz_new_display_list_from_page(ctx, page->page);
+			locked = 0;
+			muoffice_doc_unlock(page->doc->mu);
+		}
+		/* Make a pixmap from the bitmap */
+		if (!render->area_valid)
+		{
+			render->area.renderArea.x = 0;
+			render->area.renderArea.y = 0;
+			render->area.renderArea.width = render->bitmap->width;
+			render->area.renderArea.height = render->bitmap->height;
+		}
+		pixmap = fz_new_pixmap_with_data(ctx,
+						fz_device_rgb(ctx),
+						render->area.renderArea.width,
+						render->area.renderArea.height,
+						NULL,
+						1,
+						render->bitmap->lineSkip,
+						((unsigned char *)render->bitmap->memptr) +
+							render->bitmap->lineSkip * ((int)render->area.renderArea.x + (int)render->area.origin.x) +
+							4 * ((int)render->area.renderArea.y + (int)render->area.origin.y));
+		/* Be a bit clever with the scaling to make sure we get
+		 * integer width/heights. First calculate the target
+		 * width/height. */
+		page_bounds = fz_bound_page(ctx, render->page->page);
+		scalex = (int)(90 * render->zoom * (page_bounds.x1 - page_bounds.x0) / 72 + 0.5f);
+		scaley = (int)(90 * render->zoom * (page_bounds.y1 - page_bounds.y0) / 72 + 0.5f);
+		/* Now calculate the actual scale factors required */
+		scalex /= (page_bounds.x1 - page_bounds.x0);
+		scaley /= (page_bounds.y1 - page_bounds.y0);
+		/* Render the list */
+		fz_clear_pixmap_with_value(ctx, pixmap, 0xFF);
+		dev = fz_new_draw_device(ctx, fz_post_scale(fz_translate(-page_bounds.x0, -page_bounds.y0), scalex, scaley), pixmap);
+		fz_run_display_list(ctx, page->list, dev, fz_identity, fz_infinite_rect, NULL);
+		fz_close_device(ctx, dev);
+	}
+	fz_always(ctx)
+	{
+		fz_drop_pixmap(ctx, pixmap);
+		fz_drop_device(ctx, dev);
+	}
+	fz_catch(ctx)
+	{
+		if (locked)
+			muoffice_doc_unlock(page->doc->mu);
+		err = MuError_Generic;
+		goto fail;
+	}
+
+fail:
+	if (render->progress)
+		render->progress(render->cookie, err);
+	render->error = err;
+
+	fz_drop_context(ctx);
+}
+
+/**
+ * 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)
+{
+	MuOfficeRender *render;
+	MuOfficeDoc *doc;
+	fz_context *ctx;
+
+	if (!pRender)
+		return MuError_BadNull;
+	*pRender = NULL;
+	if (!page)
+		return MuError_BadNull;
+	doc = page->doc;
+	ctx = doc->ctx;
+
+	render = Pal_Mem_calloc(1, sizeof(*render));
+	if (render == NULL)
+		return MuError_OOM;
+
+	render->page = page;
+	render->zoom = zoom;
+	render->bitmap = bitmap;
+	if (area)
+	{
+		render->area = *area;
+		render->area_valid = 1;
+	}
+	else
+	{
+		render->area_valid = 0;
+	}
+	render->progress = progressFn;
+	render->cookie = cookie;
+
+	if (mu_create_thread(&render->thread, render_worker, render))
+	{
+		Pal_Mem_free(render);
+		return MuError_OOM;
+	}
+
+	*pRender = render;
+
+	return MuError_OK;
+}
+
+/**
+ * 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)
+{
+	if (!render)
+		return;
+
+	MuOfficeRender_abort(render);
+	mu_destroy_thread(&render->thread);
+	Pal_Mem_free(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)
+{
+	if (render)
+		render->mu_cookie.abort = 1;
+}
+
+/**
+ * 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)
+{
+	if (!render)
+		return MuError_OK;
+
+	mu_destroy_thread(&render->thread);
+
+	return render->error;
+}