Reflow document content in Android

Reflow makes the document more flexible and easier to read, especially on small devices. Apryse is able to extract the reflowable layout of each page in a PDF document to an HTML file. First, we explain how simple it is to show a widget that allows the user to swipe left or right through the pages of the document to see reflowable document pages. Then, we provide the methods necessary for converting a hard-layout PDF page to an HTML document page.

ReflowControl is a ViewPager that allows the user to flip left and right through the reflowable layout of pages in a PDF document.

To set up your layout with ReflowControl, add a <ReflowControl> element to your XML layout. For example, if each page in the swipe view should consume the entire layout, then your layout looks like this:

<pdftron.PDF.Controls.ReflowControl
    android:id="@+id/reflow"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />

Then, you need to attach a PDFDoc to the reflow pager:

var reflowControl = FindViewById<ReflowControl>(Resource.Id.reflow);
reflowControl.Setup(pdfDoc);

// horizontal (default)
reflowControl.Orientation = ReflowControl.Horizontal;
// vertical
reflowControl.Orientation = ReflowControl.Vertical;

To refresh the reflow pager to show the latest changes on your document, you should let the reflow pager know that the document has been modified:

void NotifyReflowModified(ReflowControl reflowControl)
{
    if (reflowControl != null && reflowControl.IsReady) {
        reflowControl.NotifyPagesModified();
    }
}

It is possible to change the size of reflowable text. The default text size is 100; valid values are 5, 10, 25, 50, 75, 100, 125, 150, 200, 400, 800, and 1600. See the following code as an example:

void ChangeReflowSize(ReflowControl reflowControl, int percent)
{
    if (reflowControl != null && reflowControl.IsReady)
    {
        reflowControl.TextSizeInPercent = percent;
    }
}

Alternatively, you can zoom in/out to change the reflowable text size:

void ZoomReflow(ReflowControl reflowControl, bool zoomIn)
{
    if (reflowControl != null && reflowControl.IsReady) {
        if (zoomIn) {
            reflowControl.ZoomIn();
        } else {
            reflowControl.ZoomOut();
        }
    }
}

Assuming the current text size is 100%, by calling zoomReflow(reflowControl, true) and zoomReflow(reflowControl, false) the new text size will be 125% and 75% of the original size, respectively.

There are three methods to change the background color:

setDayMode(): no background

setNightMode(): night background

setCustomColorMode(int): customized background

You can support right-to-left (RTL) languages by setting the direction of reflowable text by calling RightToLeftDirection