iOS: use ObjC-level ref counting to control lifetime of fz_document

With the latest version if iOS, timing changes were causing crashes
during close down of a MuDocumentController. This change isolates
us from those changes.

8 files changed, 79 insertions, 25 deletions

diff --git a/platform/ios/Classes/MuDocRef.h b/platform/ios/Classes/MuDocRef.h
new file mode 100644
index 00000000..ceefcc59
--- /dev/null
+++ b/platform/ios/Classes/MuDocRef.h
@@ -0,0 +1,18 @@
+//
+//  MuDocRef.h
+//  MuPDF
+//
+//  Copyright (c) 2013 Artifex Software, Inc. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+#include "mupdf/fitz.h"
+
+@interface MuDocRef : NSObject
+{
+@public
+	fz_document *doc;
+}
+-(id) initWithFilename:(char *)aFilename;
+@end
diff --git a/platform/ios/Classes/MuDocRef.m b/platform/ios/Classes/MuDocRef.m
new file mode 100644
index 00000000..60cfa99d
--- /dev/null
+++ b/platform/ios/Classes/MuDocRef.m
@@ -0,0 +1,35 @@
+//
+//  MuDocRef.m
+//  MuPDF
+//
+//  Copyright (c) 2013 Artifex Software, Inc. All rights reserved.
+//
+
+#include "common.h"
+#import "MuDocRef.h"
+
+@implementation MuDocRef
+
+-(id) initWithFilename:(char *)aFilename;
+{
+	self = [super init];
+	if (self)
+	{
+		dispatch_sync(queue, ^{});
+		doc = fz_open_document(ctx, aFilename);
+		if (!doc)
+			self = nil;
+	}
+	return self;
+}
+
+-(void) dealloc
+{
+	__block fz_document *block_doc = doc;
+	dispatch_async(queue, ^{
+		fz_close_document(block_doc);
+	});
+	[super dealloc];
+}
+
+@end
diff --git a/platform/ios/Classes/MuDocumentController.h b/platform/ios/Classes/MuDocumentController.h
index f5d6115a..b15d629a 100644
--- a/platform/ios/Classes/MuDocumentController.h
+++ b/platform/ios/Classes/MuDocumentController.h
@@ -14,10 +14,12 @@
 #include "mupdf/fitz.h"
 
 #import "MuOutlineController.h"
+#import "MuDocRef.h"
 
 @interface MuDocumentController : UIViewController <UIScrollViewDelegate, UISearchBarDelegate>
 {
 	fz_document *doc;
+	MuDocRef *docRef;
 	NSString *key;
 	MuOutlineController *outline;
 	UIScrollView *canvas;
@@ -34,7 +36,7 @@
 	int current; // currently visible page
 	int scroll_animating; // stop view updates during scrolling animations
 }
-- (id) initWithFilename: (NSString*)nsfilename document: (fz_document *)aDoc;
+- (id) initWithFilename: (NSString*)nsfilename document: (MuDocRef *)aDoc;
 - (void) createPageView: (int)number;
 - (void) gotoPage: (int)number animated: (BOOL)animated;
 - (void) onShowOutline: (id)sender;
diff --git a/platform/ios/Classes/MuDocumentController.m b/platform/ios/Classes/MuDocumentController.m
index 89ee0da8..0b4f7d2e 100644
--- a/platform/ios/Classes/MuDocumentController.m
+++ b/platform/ios/Classes/MuDocumentController.m
@@ -41,14 +41,15 @@ static void flattenOutline(NSMutableArray *titles, NSMutableArray *pages, fz_out
 
 @implementation MuDocumentController
 
-- (id) initWithFilename: (NSString*)filename document: (fz_document *)aDoc
+- (id) initWithFilename: (NSString*)filename document: (MuDocRef *)aDoc
 {
 	self = [super init];
 	if (!self)
 		return nil;
 
 	key = [filename retain];
-	doc = aDoc;
+	docRef = [aDoc retain];
+	doc = docRef->doc;
 
 	dispatch_sync(queue, ^{});
 
@@ -154,14 +155,7 @@ static void flattenOutline(NSMutableArray *titles, NSMutableArray *pages, fz_out
 
 - (void) dealloc
 {
-	if (doc) {
-		fz_document *self_doc = doc; // don't auto-retain self here!
-		dispatch_async(queue, ^{
-			printf("close document\n");
-			fz_close_document(self_doc);
-		});
-	}
-
+	[docRef release]; docRef = nil; doc = NULL;
 	[indicator release]; indicator = nil;
 	[slider release]; slider = nil;
 	[sliderWrapper release]; sliderWrapper = nil;
@@ -508,7 +502,7 @@ static void flattenOutline(NSMutableArray *titles, NSMutableArray *pages, fz_out
 		if ([view number] == number)
 			found = 1;
 	if (!found) {
-		MuPageView *view = [[MuPageView alloc] initWithFrame: CGRectMake(number * width, 0, width-GAP, height) document: doc page: number];
+		MuPageView *view = [[MuPageView alloc] initWithFrame: CGRectMake(number * width, 0, width-GAP, height) document: docRef page: number];
 		[canvas addSubview: view];
 		if (showLinks)
 			[view showLinks];
diff --git a/platform/ios/Classes/MuLibraryController.h b/platform/ios/Classes/MuLibraryController.h
index 2bb7ff71..0f823d5d 100644
--- a/platform/ios/Classes/MuLibraryController.h
+++ b/platform/ios/Classes/MuLibraryController.h
@@ -13,11 +13,13 @@
 
 #include "mupdf/fitz.h"
 
+#import "MuDocRef.h"
+
 @interface MuLibraryController : UITableViewController <UIActionSheetDelegate>
 {
 	NSArray *files;
 	NSTimer *timer;
-	fz_document *_doc; // temporaries for juggling password dialog
+	MuDocRef *doc;
 	NSString *_filename;
 }
 - (void) openDocument: (NSString*)filename;
diff --git a/platform/ios/Classes/MuLibraryController.m b/platform/ios/Classes/MuLibraryController.m
index cc5a1ddd..7f21b303 100644
--- a/platform/ios/Classes/MuLibraryController.m
+++ b/platform/ios/Classes/MuLibraryController.m
@@ -69,6 +69,7 @@ static void showAlert(NSString *msg, NSString *filename)
 
 - (void) dealloc
 {
+	[doc release];
 	[files release];
 	[super dealloc];
 }
@@ -163,13 +164,14 @@ static void showAlert(NSString *msg, NSString *filename)
 	printf("open document '%s'\n", filename);
 
 	_filename = [nsfilename retain];
-	_doc = fz_open_document(ctx, filename);
-	if (!_doc) {
+	[doc release];
+	doc = [[MuDocRef alloc] initWithFilename:filename];
+	if (!doc) {
 		showAlert(@"Cannot open document", nsfilename);
 		return;
 	}
 
-	if (fz_needs_password(_doc))
+	if (fz_needs_password(doc->doc))
 		[self askForPassword: @"'%@' needs a password:"];
 	else
 		[self onPasswordOkay];
@@ -193,7 +195,7 @@ static void showAlert(NSString *msg, NSString *filename)
 	char *password = (char*) [[[alertView textFieldAtIndex: 0] text] UTF8String];
 	[alertView dismissWithClickedButtonIndex: buttonIndex animated: TRUE];
 	if (buttonIndex == 1) {
-		if (fz_authenticate_password(_doc, password))
+		if (fz_authenticate_password(doc->doc, password))
 			[self onPasswordOkay];
 		else
 			[self askForPassword: @"Wrong password for '%@'. Try again:"];
@@ -204,22 +206,19 @@ static void showAlert(NSString *msg, NSString *filename)
 
 - (void) onPasswordOkay
 {
-	MuDocumentController *document = [[MuDocumentController alloc] initWithFilename: _filename document: _doc];
+	MuDocumentController *document = [[MuDocumentController alloc] initWithFilename: _filename document: doc];
 	if (document) {
 		[self setTitle: @"Library"];
 		[[self navigationController] pushViewController: document animated: YES];
 		[document release];
 	}
 	[_filename release];
-	_doc = NULL;
 }
 
 - (void) onPasswordCancel
 {
 	[_filename release];
 	printf("close document (password cancel)\n");
-	fz_close_document(_doc);
-	_doc = NULL;
 }
 
 @end
diff --git a/platform/ios/Classes/MuPageView.h b/platform/ios/Classes/MuPageView.h
index ab141ea8..58d1c8a7 100644
--- a/platform/ios/Classes/MuPageView.h
+++ b/platform/ios/Classes/MuPageView.h
@@ -13,10 +13,12 @@
 
 #include "mupdf/fitz.h"
 
+#import "MuDocRef.h"
 #include "MuHitView.h"
 
 @interface MuPageView : UIScrollView <UIScrollViewDelegate>
 {
+	MuDocRef *docRef;
 	fz_document *doc;
 	fz_page *page;
 	int number;
@@ -30,7 +32,7 @@
 	float tileScale;
 	BOOL cancel;
 }
-- (id) initWithFrame: (CGRect)frame document: (fz_document*)aDoc page: (int)aNumber;
+- (id) initWithFrame: (CGRect)frame document: (MuDocRef*)aDoc page: (int)aNumber;
 - (void) displayImage: (UIImage*)image;
 - (void) resizeImage;
 - (void) loadPage;
diff --git a/platform/ios/Classes/MuPageView.m b/platform/ios/Classes/MuPageView.m
index 53fe79b9..6fa17f54 100644
--- a/platform/ios/Classes/MuPageView.m
+++ b/platform/ios/Classes/MuPageView.m
@@ -113,11 +113,12 @@ static UIImage *renderTile(fz_document *doc, fz_page *page, CGSize screenSize, C
 
 @implementation MuPageView
 
-- (id) initWithFrame: (CGRect)frame document: (fz_document*)aDoc page: (int)aNumber
+- (id) initWithFrame: (CGRect)frame document: (MuDocRef *)aDoc page: (int)aNumber
 {
 	self = [super initWithFrame: frame];
 	if (self) {
-		doc = aDoc;
+		docRef = [aDoc retain];
+		doc = docRef->doc;
 		number = aNumber;
 		cancel = NO;
 
@@ -152,12 +153,13 @@ static UIImage *renderTile(fz_document *doc, fz_page *page, CGSize screenSize, C
 		dispatch_async(dispatch_get_main_queue(), ^{ [block_self dealloc]; });
 	} else {
 		__block fz_page *block_page = page;
-		__block fz_document *block_doc = doc;
+		__block fz_document *block_doc = docRef->doc;
 		dispatch_async(queue, ^{
 			if (block_page)
 				fz_free_page(block_doc, block_page);
 			block_page = nil;
 		});
+		[docRef release];
 		[linkView release];
 		[hitView release];
 		[tileView release];