Paged scroll view with automatic loading and unloading of pages.

1 files changed, 267 insertions, 45 deletions

diff --git a/ios/main.m b/ios/main.m
index b03fd42c..bc34212e 100644
--- a/ios/main.m
+++ b/ios/main.m
@@ -8,47 +8,135 @@
 #include "pdf/mupdf.h"
 #include "xps/muxps.h"
 
-@interface MuOutline : UITableViewController
-{
-}
-@end
-
-@interface MuDocument : UIViewController
-{
-}
-@end
-
-@interface MuLibrary : UITableViewController
-{
-	NSArray *files;
-}
-@end
+@interface MuLibrary : UITableViewController { NSArray *files; } @end
+@interface MuOutline : UITableViewController { NSArray *pages; } @end
+@interface MuDocument : UIViewController { } @end
 
 @interface MuAppDelegate : NSObject <UIApplicationDelegate>
 {
 	UIWindow *window;
 	UINavigationController *navigator;
+	UIScrollView *canvas;
 	MuLibrary *library;
 	MuDocument *document;
 	MuOutline *outline;
+	UIView **pageviews;
+	int width; // current screen width
+	int height; // tallest page so far
+	int current; // currently visible page
 }
-- (void) doOpenDocument: (NSString*)filename;
-- (void) doCloseDocument;
-- (void) doShowOutline;
-- (void) doHideOutline;
+- (void) onOpenDocument: (NSString*)filename;
+- (void) closeDocument;
+- (void) onShowOutline;
+- (void) onHideOutline;
+- (void) onReconfigure;
+- (void) loadPage: (int)number;
+- (void) unloadPage: (int)number;
+- (void) onGotoPage: (int)number;
 @end
 
+static fz_glyph_cache *glyphcache = NULL;
+static pdf_xref *xref = NULL;
 static MuAppDelegate *app = nil;
 
 #pragma mark -
 
-@implementation MuOutline
-@end
+static void show_alert(NSString *msg)
+{
+	UIAlertView *alert = [[UIAlertView alloc]
+		initWithTitle: @"Error"
+		message: msg
+		delegate: nil
+		cancelButtonTitle: @"Okay"
+		otherButtonTitles: nil];
+	[alert show];
+	[alert release];
+}
+
+static int get_page_number(pdf_xref *xref, pdf_link *link)
+{
+	if (link->kind == PDF_LINK_GOTO)
+		return pdf_find_page_number(xref, fz_array_get(link->dest, 0));
+	return 0;
+}
+
+static void release_pixmap(void *info, const void *data, size_t size)
+{
+	fz_drop_pixmap(info);
+}
+
+static UIImage *convert_pixmap(fz_pixmap *pix)
+{
+	CGDataProviderRef cgdata = CGDataProviderCreateWithData(pix, pix->samples, pix->w * 4 * pix->h, release_pixmap);
+	CGImageRef cgimage = CGImageCreate(pix->w, pix->h, 8, 32, 4 * pix->w,
+			CGColorSpaceCreateDeviceRGB(),
+			kCGBitmapByteOrderDefault,
+			cgdata, NULL, NO, kCGRenderingIntentDefault);
+	UIImage *image = [UIImage imageWithCGImage: cgimage];
+	CGDataProviderRelease(cgdata);
+	CGImageRelease(cgimage);
+	return image;
+}
+
+// TODO: custom view with hyperlinks
+static UIImageView *new_page_view(pdf_xref *xref, int number, float width)
+{
+	fz_bbox bbox;
+	fz_matrix ctm;
+	fz_device *dev;
+	fz_pixmap *pix;
+	pdf_page *page;
+	fz_error error;
+	float scale;
+	float pw;
+
+	error = pdf_load_page(&page, xref, number);
+	if (error)
+	{
+		show_alert(@"Cannot load page");
+		return [[UIImageView alloc] initWithImage: [UIImage imageNamed: @"mupdf_icon.png"]];
+	}
+
+	pw = page->mediabox.x1 - page->mediabox.x0;
+	scale = width / pw;
+
+	ctm = fz_translate(0, -page->mediabox.y1);
+	ctm = fz_concat(ctm, fz_scale(scale, -scale));
+	ctm = fz_concat(ctm, fz_rotate(page->rotate));
+	bbox = fz_round_rect(fz_transform_rect(ctm, page->mediabox));
+
+	pix = fz_new_pixmap_with_rect(fz_device_rgb, bbox);
+	fz_clear_pixmap_with_color(pix, 255);
+
+	dev = fz_new_draw_device(glyphcache, pix);
+	pdf_run_page(xref, page, dev, ctm);
+	fz_free_device(dev);
+
+	pdf_free_page(page);
+	pdf_age_store(xref->store, 3);
+	fz_flush_warnings();
+
+	return [[UIImageView alloc] initWithImage: convert_pixmap(pix)];
+}
+
+#pragma mark -
 
 @implementation MuDocument
+
+- (BOOL) shouldAutorotateToInterfaceOrientation: (UIInterfaceOrientation)o
+{
+	return YES;
+}
+
+- (void) didRotateFromInterfaceOrientation: (UIInterfaceOrientation)o
+{
+	[app onReconfigure];
+}
+
 @end
 
-#pragma mark -
+@implementation MuOutline
+@end
 
 @implementation MuLibrary
 
@@ -73,6 +161,11 @@ static MuAppDelegate *app = nil;
 	[super dealloc];
 }
 
+- (BOOL) shouldAutorotateToInterfaceOrientation: (UIInterfaceOrientation)o
+{
+	return YES;
+}
+
 - (NSInteger) numberOfSectionsInTableView: (UITableView*)tableView
 {
 	return 1;
@@ -97,7 +190,7 @@ static MuAppDelegate *app = nil;
 - (void) tableView: (UITableView*)tableView didSelectRowAtIndexPath: (NSIndexPath*)indexPath
 {
 	NSString *filename = [files objectAtIndex: [indexPath row]];
-	[app doOpenDocument: filename];
+	[app onOpenDocument: filename];
 }
 
 @end
@@ -110,14 +203,20 @@ static MuAppDelegate *app = nil;
 {
 	app = self;
 
-	library = [[MuLibrary alloc] initWithStyle: UITableViewStylePlain];
+	glyphcache = fz_new_glyph_cache();
 
+	library = [[MuLibrary alloc] initWithStyle: UITableViewStylePlain];
+	// outline = [[MuOutline alloc] initWithStyle: UITableViewStylePlain];
 	document = [[MuDocument alloc] init];
-	[[document view] setBackgroundColor: [UIColor yellowColor]];
-
-	outline = [[MuOutline alloc] initWithStyle: UITableViewStylePlain];
 
 	navigator = [[UINavigationController alloc] initWithRootViewController: library];
+	[navigator setDelegate: app];
+
+	canvas = [[UIScrollView alloc] initWithFrame: [[navigator view] bounds]];
+	[canvas setBackgroundColor: [UIColor grayColor]];
+	[canvas setPagingEnabled: YES];
+	[canvas setDelegate: app];
+	[document setView: canvas];
 
 	window = [[UIWindow alloc] initWithFrame: [[UIScreen mainScreen] bounds]];
 	[window addSubview: [navigator view]];
@@ -126,50 +225,169 @@ static MuAppDelegate *app = nil;
 	return YES;
 }
 
-//	[library presentModalViewController: document animated: NO];
-//	[library dismissModalViewControllerAnimated: NO];
-
-- (void) doShowOutline
+- (void) onShowOutline
 {
 	[outline setTitle: @"Table of Contents"];
-	[navigator pushViewController: document animated: YES];
+	[navigator pushViewController: outline animated: YES];
 }
 
-- (void) doHideOutline
+- (void) onHideOutline
 {
 	[navigator popViewControllerAnimated: YES];
 }
 
-- (void) doOpenDocument: (NSString*)filename
+- (void) onOpenDocument: (NSString*)nsfilename
 {
-	[document setTitle: filename];
+	fz_error error;
+	char filename[PATH_MAX];
+	char *password = "";
+
+	strcpy(filename, [NSHomeDirectory() UTF8String]);
+	strcat(filename, "/Documents/");
+	strcat(filename, [nsfilename UTF8String]);
+
+	NSLog(@"filename = '%s'\n", filename);
+
+	error = pdf_open_xref(&xref, filename, password);
+	if (error)
+	{
+		show_alert(@"Cannot open document");
+		return;
+	}
+
+	error = pdf_load_page_tree(xref);
+	if (error)
+	{
+		show_alert(@"Cannot load page list");
+		return;
+	}
+
+	[document setTitle: nsfilename];
+
+	current = 0;
+	pageviews = calloc(pdf_count_pages(xref), sizeof *pageviews);
+
+	[self onReconfigure];
+
 	[navigator pushViewController: document animated: YES];
 }
 
-- (void) doCloseDocument
+- (void) closeDocument
 {
-	[navigator popViewControllerAnimated: YES];
+	if (xref)
+	{
+		for (int i = 0; i < pdf_count_pages(xref); i++)
+			[self unloadPage: i];
+		pdf_free_xref(xref);
+		xref = NULL;
+	}
 }
 
-- (void)applicationDidEnterBackground:(UIApplication *)application {
+- (void) onReconfigure
+{
+	int i;
+
+	width = [[navigator view] bounds].size.width;
+	height = 0;
+
+	for (i = 0; i < pdf_count_pages(xref); i++)
+		[self unloadPage: i];
+
+	[canvas setContentSize: CGSizeMake(pdf_count_pages(xref) * width, 10)];
+	[canvas setContentOffset: CGPointMake(current * width, 0) animated: NO];
+
+	[app scrollViewDidScroll: canvas];
+}
+
+- (void) loadPage: (int)number
+{
+	if (number < 0 || number >= pdf_count_pages(xref))
+		return;
+	if (!pageviews[number])
+	{
+printf("load page %d\n", number);
+		UIImageView *page = new_page_view(xref, number, width);
+
+		CGRect frame = [page frame];
+		frame.origin.x = number * width;
+		[page setFrame: frame];
+
+		height = MAX(height, frame.size.height);
+
+		[canvas setContentSize: CGSizeMake(pdf_count_pages(xref) * width, height)];
+		[canvas addSubview: page];
+
+		pageviews[number] = page;
+	}
+}
+
+- (void) unloadPage: (int)number
+{
+	if (number < 0 || number >= pdf_count_pages(xref))
+		return;
+	if (pageviews[number])
+	{
+printf("unload %d\n", number);
+		[pageviews[number] removeFromSuperview];
+		[pageviews[number] release];
+		pageviews[number] = nil;
+	}
+}
+
+- (void) onGotoPage: (int)number
+{
+	current = number;
+	[canvas setContentOffset: CGPointMake(current * width, 0) animated: YES];
+printf("onGotoPage!\n");
+	// [app scrollViewDidScroll: canvas];
+}
+
+- (void) scrollViewDidScroll: (UIScrollView*)scrollview
+{
+	float x = [canvas contentOffset].x;
+	int i;
+
+	current = x / width;
+
+	for (i = 0; i < current - 2; i++)
+		[self unloadPage: i];
+	for (i = current + 2; i < pdf_count_pages(xref); i++)
+		[self unloadPage: i];
+
+	[self loadPage: current];
+	[self loadPage: current - 1];
+	[self loadPage: current + 1];
+}
+
+- (void) navigationController:(UINavigationController *)navigationController didShowViewController:(UIViewController *)viewController animated:(BOOL)animated
+{
+	// popped back to document picker
+	if (viewController == library)
+		[self closeDocument];
+}
+
+- (void)applicationDidEnterBackground:(UIApplication *)application
+{
 	/*
 	 Use this method to release shared resources, save user data, invalidate timers,
 	 and store enough application state information to restore your application to
-	 its current state in case it is terminated later. 
+	 its current state in case it is terminated later.
 	 If your application supports background execution,
 	 called instead of applicationWillTerminate: when the user quits.
 	 */
 }
 
-- (void)applicationWillEnterForeground:(UIApplication *)application {
+- (void)applicationWillEnterForeground:(UIApplication *)application
+{
 	/*
 	 Called as part of	transition from the background to the
-	 inactive state: here you can undo many of the changes made 
+	 inactive state: here you can undo many of the changes made
 	 on entering the background.
 	 */
 }
 
-- (void)applicationDidBecomeActive:(UIApplication *)application {
+- (void)applicationDidBecomeActive:(UIApplication *)application
+{
 	/*
 	 Restart any tasks that were paused (or not yet started) while
 	 the application was inactive. If the application was previously
@@ -177,14 +395,16 @@ static MuAppDelegate *app = nil;
 	 */
 }
 
-- (void)applicationWillTerminate:(UIApplication *)application {
+- (void)applicationWillTerminate:(UIApplication *)application
+{
 	/*
 	 Called when the application is about to terminate.
 	 See also applicationDidEnterBackground:.
 	 */
 }
 
-- (void)applicationDidReceiveMemoryWarning:(UIApplication *)application {
+- (void)applicationDidReceiveMemoryWarning:(UIApplication *)application
+{
 	/*
 	 Free up as much memory as possible by purging cached data objects that can
 	 be recreated (or reloaded from disk) later.
@@ -193,8 +413,10 @@ static MuAppDelegate *app = nil;
 
 - (void) dealloc
 {
+	[canvas release];
 	[document release];
 	[library release];
+	[navigator release];
 	[window release];
 	[super dealloc];
 }
@@ -204,7 +426,7 @@ static MuAppDelegate *app = nil;
 #pragma mark -
 
 int main(int argc, char *argv[])
-{	 
+{
 	NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
 	int retVal = UIApplicationMain(argc, argv, nil, @"MuAppDelegate");
 	[pool release];