Override the pinch zoom in iPad/Android HTML5 PDF viewer with a double tap to a fixed zoom.

[Support]

Q: We wanted to override the pinch zoom in Mobile PDF viewer for iPad/
Android and replace with a double tap to a fixed zoom ratio. Is this
possible and then have control over the page navigation in the zoomed
state.

So to clarify – double tap zoom, double tap again unzoom.

--------------

A: jQuery mobile, does not have a double tap event so you would need
to use a different library.

For example, you could use the approach described on the following
page http://appcropolis.com/blog/implementing-doubletap-on-iphones-and-ipads/.
Once you have the event you can do something like the following:

var zoomed = false;
$(document).bind(“doubletap”, function(){
If (zoomed === false){
zoomed = true;
//zoom to 250%
me.docViewer.ZoomTo(2.5);
}else{
zoomed = false;
//zoom to 100%
me.docViewer.ZoomTo(1);
}
});

[ch...@cwfent.com]

Is it possible to have this functionality with the non-mobile, aka the ReaderControl.js?

TIA

[Matt Parizeau]

Hi,

We don't recommend using the desktop viewer on mobile devices if that's what you mean.  However if you wanted a double click zoom, or double tap for devices that use the desktop viewer but also have a touch interface then yes it is possible, probably by doing something similar to the code posted above.

Matt Parizeau

Software Developer

PDFTron Systems Inc.

[ch...@cwfent.com]

Yes, sorry I didn't mean mobile. I was talking about the regular HTML5 viewer that appears when using ff, ie, chrome etc on your desktop. That's where I'd really like to be able to also click zoom.

Thanks!
-Chris