Rendering ePub in two page mode

Question

I am using AePubreader sample code for reading ePub in my app. The issue I am facing is that the last page of the chapters are not rendered properly and they go off the visible area. I had edited AePubreader code in following way to convert in a two page mode in ipad.

-In chaper.m file the webViewDiDFinishLoading has following code :

- (void) webViewDidFinishLoad:(UIWebView*)webView{
    NSString *varMySheet = @"var mySheet = document.styleSheets[0];";


    NSString *addCSSRule =  @"function addCSSRule(selector, newRule) {"
    "if (mySheet.addRule) {"
        "mySheet.addRule(selector, newRule);"                               // For Internet Explorer
    "} else {"
        "ruleIndex = mySheet.cssRules.length;"
        "mySheet.insertRule(selector + '{' + newRule + ';}', ruleIndex);"   // For Firefox, Chrome, etc.
    "}"
    "}";


NSString *insertRule1 = [NSString stringWithFormat:@"addCSSRule('html', 'padding-left: 0px;padding-right: 0px; padding-top: 0px; padding-bottom: 0px; height: %fpx;-webkit-column-count: 2; -webkit-column-gap: 0px; ')", webView.frame.size.height];    

    NSString *insertRule2 = [NSString stringWithFormat:@"addCSSRule('p', 'text-align: justify;')"];
    NSString *setTextSizeRule = [NSString stringWithFormat:@"addCSSRule('body', '-webkit-text-size-adjust: %d%%;')",fontPercentSize];

    NSString *setImageRule = [NSString stringWithFormat:@"addCSSRule('img', 'max-width: %fpx; height:%fpx;')", webView.frame.size.width-200,webView.frame.size.height-200];


    NSString *setFontRule = [NSString stringWithFormat:@"addCSSRule('body', 'font-family: Arial;' , 'font-name: Arial-BoldItalicMT;')"];

    [webView stringByEvaluatingJavaScriptFromString:setFontRule];
    [webView stringByEvaluatingJavaScriptFromString:setImageRule];

    [webView stringByEvaluatingJavaScriptFromString:varMySheet];

    [webView stringByEvaluatingJavaScriptFromString:addCSSRule];

    [webView stringByEvaluatingJavaScriptFromString:insertRule1];

    [webView stringByEvaluatingJavaScriptFromString:insertRule2];

    [webView stringByEvaluatingJavaScriptFromString:setTextSizeRule];

    float totalWidth = [[webView stringByEvaluatingJavaScriptFromString:@"document.body.scrollWidth"] floatValue];
    pageCount = (ceilf)((float)totalWidth/webView.frame.size.width);

    NSLog(@"Chapter %d: %@ -> %d pages & totalWidth :: %f", chapterIndex, title, pageCount,totalWidth);

    [webView dealloc];
    [delegate chapterDidFinishLoad:self];

}

In EpubViewController.m webViewDidFinishLoading is as follows:-

- (void)webViewDidFinishLoad:(UIWebView *)theWebView{

    NSString *varMySheet = @"var mySheet = document.styleSheets[0];";

    NSString *addCSSRule =  @"function addCSSRule(selector, newRule) {"
    "if (mySheet.addRule) {"
    "mySheet.addRule(selector, newRule);"                               // For Internet Explorer
    "} else {"
    "ruleIndex = mySheet.cssRules.length;"
    "mySheet.insertRule(selector + '{' + newRule + ';}', ruleIndex);"   // For Firefox, Chrome, etc.
    "}"
    "}";



NSString *insertRule1 = [NSString stringWithFormat:@"addCSSRule('html', 'padding-left: 0px;padding-right: 0px; padding-top: 0px; padding-bottom: 0px; height: %fpx;-webkit-column-count: 2; -webkit-column-gap: 0px; ')", webView.frame.size.height];    


    NSString *insertRule2 = [NSString stringWithFormat:@"addCSSRule('p', 'text-align: justify;')"];
    NSString *setTextSizeRule = [NSString stringWithFormat:@"addCSSRule('body', '-webkit-text-size-adjust: %d%%;')", currentTextSize];
    NSString *setHighlightColorRule = [NSString stringWithFormat:@"addCSSRule('highlight', 'background-color: yellow;')"];

    NSString *setImageRule = [NSString stringWithFormat:@"addCSSRule('img', 'max-width: %fpx; height:%fpx;')", (webView.frame.size.width/2)-200,webView.frame.size.height-150];

    NSString *setFontRule = [NSString stringWithFormat:@"addCSSRule('body', 'font-family: Arial;' , 'font-name: Arial-BoldItalicMT;')"];

    [webView stringByEvaluatingJavaScriptFromString:setFontRule];

    [webView stringByEvaluatingJavaScriptFromString:setImageRule];

    [webView stringByEvaluatingJavaScriptFromString:varMySheet];

    [webView stringByEvaluatingJavaScriptFromString:addCSSRule];

    [webView stringByEvaluatingJavaScriptFromString:insertRule1];

    [webView stringByEvaluatingJavaScriptFromString:insertRule2];

    [webView stringByEvaluatingJavaScriptFromString:setTextSizeRule];

    [webView stringByEvaluatingJavaScriptFromString:setHighlightColorRule];

    if(currentSearchResult!=nil){
    //  NSLog(@"Highlighting %@", currentSearchResult.originatingQuery);
        [webView highlightAllOccurencesOfString:currentSearchResult.originatingQuery];
    }

//  int totalWidth = [[webView stringByEvaluatingJavaScriptFromString:@"document.documentElement.scrollWidth"] intValue];

//    NSLog(@">>>>>>>>>>>>>>>>>>>>>>>total width is %d",totalWidth);
//    CGFloat moduloResult = (float)(totalWidth/((int)webView.bounds.size.width % 2));

  //NSLog(@"moduloresult is %f",moduloResult);

//  pagesInCurrentSpineCount = (round)((float)totalWidth/(webView.frame.size.width));
    float pageCountofChapter = [[loadedEpub.spineArray objectAtIndex:currentSpineIndex] pageCount];
    pagesInCurrentSpineCount =(ceilf)(pageCountofChapter/2.0);

    UIScrollView* sv = nil;
    for (UIView* v in  webView.subviews) {
        if([v isKindOfClass:[UIScrollView class]])
        {
            sv = (UIScrollView*) v;
            sv.contentSize = CGSizeMake(pagesInCurrentSpineCount*1024, sv.contentSize.height);
        }
    }

//    NSLog(@"TotalWidth :: %d && pagesInCurrentSpineCount :: %d  && currentPageInSpineIndex :: %d",totalWidth,pagesInCurrentSpineCount,currentPageInSpineIndex);

    [self gotoPageInCurrentSpine:currentPageInSpineIndex];
}

I have noticed that when the pages calculated are in odd numbers the last page of the chapter is not rendered properly ? Also , is there any alternative library available which provides two page mode support to accurately render epub?

Answer 1

@dineshprasanna do following changes in your project.

in chapter.m file

- (void) webViewDidFinishLoad:(UIWebView*)webView{
    NSString *varMySheet = @"var mySheet = document.styleSheets[0];";


    NSString *addCSSRule =  @"function addCSSRule(selector, newRule) {"
    "if (mySheet.addRule) {"
        "mySheet.addRule(selector, newRule);"                               // For Internet Explorer
    "} else {"
        "ruleIndex = mySheet.cssRules.length;"
        "mySheet.insertRule(selector + '{' + newRule + ';}', ruleIndex);"   // For Firefox, Chrome, etc.
    "}"
    "}";

//  NSLog(@"w:%f h:%f", webView.bounds.size.width, webView.bounds.size.height);



   NSString *insertRule1 = [NSString stringWithFormat:@"addCSSRule('html', 'padding-left: 50px;padding-right: 50px; padding-top: 50px; padding-bottom: 50px; -webkit-column-gap: 100px;height: %fpx; -webkit-column-width : %fpx')", webView.frame.size.height-100,webView.frame.size.width/2-200];    

    NSString *insertRule2 = [NSString stringWithFormat:@"addCSSRule('p', 'text-align: justify;')"];
    NSString *setTextSizeRule = [NSString stringWithFormat:@"addCSSRule('body', '-webkit-text-size-adjust: %d%%;')",fontPercentSize];

//    NSString *setImageRule = [NSString stringWithFormat:@"addCSSRule('img', 'max-width: %fpx; height:auto;')", webView.frame.size.width *0.75];
    NSString *setImageRule = [NSString stringWithFormat:@"addCSSRule('img', 'max-width: %fpx; height:%fpx;')", webView.frame.size.width/2-200,webView.frame.size.height-200];


    NSString *setFontRule = [NSString stringWithFormat:@"addCSSRule('body', 'font-family: Arial;' , 'font-name: Arial-BoldItalicMT;')"];

    [webView stringByEvaluatingJavaScriptFromString:setFontRule];
    [webView stringByEvaluatingJavaScriptFromString:setImageRule];

    [webView stringByEvaluatingJavaScriptFromString:varMySheet];

    [webView stringByEvaluatingJavaScriptFromString:addCSSRule];

    [webView stringByEvaluatingJavaScriptFromString:insertRule1];

    [webView stringByEvaluatingJavaScriptFromString:insertRule2];

    [webView stringByEvaluatingJavaScriptFromString:setTextSizeRule];

    int totalWidth = [[webView stringByEvaluatingJavaScriptFromString:@"document.documentElement.scrollWidth"] floatValue];
    pageCount = (ceilf)((float)totalWidth/webView.frame.size.width);

    if (totalWidth % (int)webView.frame.size.width != 0)
    {
        UIScrollView *scrollV = [self getScrollViewFromWebView:webView];
        scrollV.contentSize = CGSizeMake(pageCount*(webView.frame.size.width), webView.scrollView.contentSize.height);

    }


    NSLog(@"Chapter %d: %@ -> %d pages & totalWidth :: %d", chapterIndex, title, pageCount,totalWidth);

    [activityIndicator removeFromSuperview];
    [activityIndicator stopAnimating];
    [webView dealloc];


    [delegate chapterDidFinishLoad:self];

}

in your epubviewcontroller file :-

- (void)webViewDidFinishLoad:(UIWebView *)theWebView{

    NSString *varMySheet = @"var mySheet = document.styleSheets[0];";

    NSString *addCSSRule =  @"function addCSSRule(selector, newRule) {"
    "if (mySheet.addRule) {"
    "mySheet.addRule(selector, newRule);"                               // For Internet Explorer
    "} else {"
    "ruleIndex = mySheet.cssRules.length;"
    "mySheet.insertRule(selector + '{' + newRule + ';}', ruleIndex);"   // For Firefox, Chrome, etc.
    "}"
    "}";



//    NSString *insertRule1 = [NSString stringWithFormat:@"addCSSRule('html', 'PADDING-LEFT: 25px; padding-top: 100px; padding-right: 25px; height: %fpx; -webkit-column-gap: 50px; -webkit-column-width:%fpx;')", webView.frame.size.height-200, (webView.frame.size.width/2-100) ];

    NSString *insertRule1 = [NSString stringWithFormat:@"addCSSRule('html', 'padding-left: 50px;padding-right: 50px; padding-top: 50px; padding-bottom: 50px; -webkit-column-gap: 100px;height: %fpx; -webkit-column-width : %fpx')", webView.frame.size.height-100,webView.frame.size.width/2-200];     


    NSString *insertRule2 = [NSString stringWithFormat:@"addCSSRule('p', 'text-align: justify;')"];
    NSString *setTextSizeRule = [NSString stringWithFormat:@"addCSSRule('body', '-webkit-text-size-adjust: %d%%;')", currentTextSize];
    NSString *setHighlightColorRule = [NSString stringWithFormat:@"addCSSRule('highlight', 'background-color: yellow;')"];

    NSString *setImageRule = [NSString stringWithFormat:@"addCSSRule('img', 'max-width: %fpx; height:%fpx;')", (webView.frame.size.width/2)-200,webView.frame.size.height-200];

    NSString *setFontRule = [NSString stringWithFormat:@"addCSSRule('body', 'font-family: Arial;' , 'font-name: Arial-BoldItalicMT;')"];

    [webView stringByEvaluatingJavaScriptFromString:setFontRule];

    [webView stringByEvaluatingJavaScriptFromString:setImageRule];

    [webView stringByEvaluatingJavaScriptFromString:varMySheet];

    [webView stringByEvaluatingJavaScriptFromString:addCSSRule];

    [webView stringByEvaluatingJavaScriptFromString:insertRule1];

    [webView stringByEvaluatingJavaScriptFromString:insertRule2];

    [webView stringByEvaluatingJavaScriptFromString:setTextSizeRule];

    [webView stringByEvaluatingJavaScriptFromString:setHighlightColorRule];

    if(currentSearchResult!=nil){
    //  NSLog(@"Highlighting %@", currentSearchResult.originatingQuery);
        [webView highlightAllOccurencesOfString:currentSearchResult.originatingQuery];
    }


    float pageCountofChapter = [[loadedEpub.spineArray objectAtIndex:currentSpineIndex] pageCount];
    pagesInCurrentSpineCount =pageCountofChapter;

    int totalWidth = [[webView stringByEvaluatingJavaScriptFromString:@"document.documentElement.scrollWidth"] floatValue];

    if (totalWidth % (int)webView.frame.size.width != 0)
    {
        UIScrollView *scrollV = [self getScrollViewFromWebView:webView];
        scrollV.contentSize = CGSizeMake(pagesInCurrentSpineCount*(webView.frame.size.width), webView.scrollView.contentSize.height);

    }

    [self gotoPageInCurrentSpine:currentPageInSpineIndex];
}

Hope this will help you. Arrange the padding and margin as per your requirement.

Answer 2

I had changed the logic by providing column numbers and managed contentsize for the scrollview of webview when it is not in the multiple of page width. Thanks for your time