转到epub阅读器中的Page(PageTurner)

Question

我必须在epub阅读器中实现Go To Page功能.我尝试在Page-Turner的源代码中实现此功能,但由于.epub文件中存在多个xhtml,因此无法成功运行,因为我们知道每个章节都有单个xhtml文件,并且在此应用程序中按照屏幕大小划分.因此,每当屏幕尺寸较大时,当屏幕较小时,总页数就会越来越少,因此没有固定页码可以跳转到哪里.我编辑并尝试实现如下的给予者.

ReadingFragment.java

public void performSearch(String query) {

    int index = Integer.parseInt(query);

    if (index > bookView.getTotalNumberOfPages()) {
        Toast.makeText(context, "Please enter number between 0 to " + bookView.getTotalNumberOfPages(), Toast.LENGTH_SHORT).show();
    } else {
        bookView.gotoPageNumber(index);
    }
}

BookView.java

public void gotoPageNumber(int pageNum) {
    strategy.gotoPage(pageNum);
    progressUpdate();
}

PageChangeStrategy.java

public void gotoPage(int pageNumber);

FixedPagesStrategy.java

@Override
public void gotoPage(int pageNumber) {

    PageTurnerSpine spinePos = bookView.getSpine();

    this.storedPosition = -1;

    int currentPage = getCurrentPage() + spinePos.getUptoPage(spinePos.getPosition());
    Log.e(TAG, "Adding >> Upto Page : " + spinePos.getUptoPage(spinePos.getPosition())
            + ", currentPage :  " + getCurrentPage());
    Log.e(TAG, "pagenum : " + pageNum);

    if (pageNumber > currentPage) {     //pageNumber is greater then current page

        int jumpSpine = spinePos.getIndexFromPage(pageNumber);
        int currentSpine = spinePos.getPosition();
        Log.e(TAG, "jumpSpine : " + jumpSpine + ", currentSpine : " + currentSpine);

        if (jumpSpine == currentSpine) {

            int diffrence = pageNumber - currentPage;
            Log.e(TAG, "diffrence < : " + diffrence);

            Log.e(TAG, "Minimum >> PageOffSets - 1 : " + (spinePos.getPageOffSets(currentSpine) - 1)
                    + ", pageNum + diffrence : " + (pageNum + diffrence));

            this.pageNum = Math.min(pageNum + diffrence, spinePos.getPageOffSets(currentSpine) - 1);
            updatePosition();

        } else {

            PageTurnerSpine spine = bookView.getSpine();

            if (spine == null || !spine.navigateFrontSpine(spine.getIndexFromPage(pageNumber))) {
                return;
            }
            this.pageNum = 0;

            gotoPage(pageNumber);

        }

    } else {                            //pageNumber is less then current page

        int jumpSpine = spinePos.getIndexFromPage(pageNumber);
        int currentSpine = spinePos.getPosition();
        Log.e(TAG, "jumpSpine : " + jumpSpine + ", currentSpine : " + currentSpine);

        if (jumpSpine == currentSpine) {

            int diffrence = currentPage - pageNumber;
            Log.e(TAG, "diffrence > : " + diffrence);

            Log.e(TAG, "pagenum - diffrence : " + (pageNum - diffrence));

            this.pageNum = Math.max(pageNum - diffrence, 0);
            updatePosition();

        } else {

            PageTurnerSpine spine = bookView.getSpine();

            if (spine == null || !spine.navigateBackSpine(spine.getIndexFromPage(pageNumber))) {
                return;
            }
            this.pageNum = 0;

            gotoPage(pageNumber);
        }
    }

    Log.e(TAG, "In last pageNum : " + pageNum);
}

PageTurnerSpine.java

public int getIndexFromPage(int pageNumber) {
    int total = 0;
    int totalIndex = 0;

    for (List<Integer> pagesPerSection : pageOffsets) {
        total += pagesPerSection.size();
        totalIndex = totalIndex + 1;
        if (total - 1 >= pageNumber) {
            return totalIndex - 1;
        }
    }
    return 0;
}

public int getUptoPage(int position) {
    int total = 0, max = 0;
    for (List<Integer> pagesPerSection : pageOffsets) {
        max = max + 1;

        if (position == max - 1) {
            return total;
        }
        total += pagesPerSection.size();
    }
    return 0;
}

public int getPageOffSets(int position) {
    int max = 0;
    for (List<Integer> pagesPerSection : pageOffsets) {
        max = max + 1;

        if (position == max - 1) {
            return pagesPerSection.size();
        }
    }
    return 0;
}

public boolean navigateFrontSpine(int indexSpine) {

    if (this.position == size() - 1) {
        return false;
    }

    this.position = indexSpine;
    return true;
}

public boolean navigateBackSpine(int indexSpine) {

    if (this.position == 0) {
        return false;
    }

    this.position = indexSpine;
    return true;
}

当我应用此代码并运行一段时间它正常工作.但是有一段时间它跳到其他页码上,就像我输入110然后它会跳到109.当我试图跳到章节起始页然后包含剂量没有变化.请帮我.

https://github.com/NightWhistler/PageTurner 在这个源代码中,我编辑了上面给出的一些文件.它们已经存在于这个项目中.

大多数情况下,我看到像Kindle,FBReader等大多数epub读者都没有实现Go To Page功能.所以,我还想知道是否可以实现此功能？

感谢帮助 :)

Answer 1

您确实需要在IDPF.org/epub上查阅 IDPF Epub 标准。

我认为在标准中是可选的一种方法（但不确定）是用纸质书（如果有的话）中的物理页码标记内容，或者决定您自己的编号系统以及您的表格目录，并使用相应的虚拟页面作为其开始。

这使得可以转到同一页面的开头，但每个物理页面的虚拟页面数量将有所不同，具体取决于当前使用的字体大小等。

这是一个数据问题，也是一个编程问题。