Slowness on mobile devices

[lalith-b]

I saw the original document on the safari browser on my iPad and then I tried to see the html version. its very difficult/glitchy to scroll the document (Not as smooth as the pdf rendering engine in iOS.) Can it be made more smoother with zoom controls on pinch up and pinch down ?

[iapain]

Try loading pages one by one in dom via ajax. It works better.

[coolwanglu]

It's a known issue, optimization for mobile devices will be done later, and, as @iapain said, might be a work of the frontend.

[lalith-b]

This alone can make this project as a standalone super feature. Most of the pdf2html converters dont support mobile devices and most of mobile devices has inbuilt javascript based rendering mechanism which screws up the UI. It is really a nice to have feature if there's mobile support for the html's like a command line arg--

pdf2htmlEx somefile.pdf --ipad
pdf2htmlEx somefile.pdf --iphone3.5inch
pdf2htmlEx somefile.pdf --iphone5

what do you guys think about this ?

[coolwanglu]

Can you elaborate what should be done, for example, especially for iphone5 ?

[iapain]

Pardon me, what these options going to do? Problem is that PDF is usually fixed layout document and text won't re-flow on mobile devices, that is the core problem on small screen devices.

However, I am in a favour of adding support for preset files. e.g. ipad.preset which would contain something like this --zoom 1.33 --space-as-offset 1 --tounicode -1.

[coolwanglu]

Yes, somebody asked me about this before.

I've not found a trivial way to make GetOpt accepting a file as
supplementary parameters.

So maybe I need parse some format myself.

I'll use JSON if I'm writing in Python, but how about C++?

Anyway it'll be a 'user-experience' feature, but not a 'technical'
features, which is far less interesting to me...

Speaking of mobile devices, will it be faster if images are not included,
say --process-nontext 0. Or maybe it will improve loading time only?

On Wed, Oct 3, 2012 at 6:58 PM, Deepak notifications@github.com wrote:

Pardon me, what these options going to do? Problem is that PDF is usually
fixed layout document and text won't re-flow on mobile devices, that is the
core problem on small screen devices.

However, I am in a favour of adding support for preset files. e.g.
ipad.preset which would contain something like this --zoom 1.33
--space-as-offset 1 --tounicode -1.

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/30#issuecomment-9102427.

[coolwanglu]

Another obstacle is that I've got no smart phones. So no way for me to optimize/test/debug.

[coolwanglu]

@iapain btw, --fit-width might be better for you

[lalith-b]

for presets basically which has ipad/iphone may display html content with no grey space and the page zoomed to the particular size (ipad 1024x768 for landscape and 768x1024 for portrait in viewport setting in meta tag and for iPhone <iPhone 5 will have 320x480 where as iPhone5 will have 640x1136).

for scrolling iscroll js can be used to make it smoother - http://cubiq.org/iscroll

simple tweaks which make this a better for use on all platforms. I hope i'm making clear of the objective and not deviating.

@coolwanglu you can use some online simulations like http://quirktools.com/screenfly/ which will help you to view on simulators, its very close to a real device but its never = to a real device.

[lalith-b]

yeah I tried --fit-width but the issue arised when turning the device to landscape and portrait mode. The grey spaces will show up when turning the devices.

[coolwanglu]

Still not clear withe the viewports.

What do you expect when you rotate your device?

On Wed, Oct 3, 2012 at 7:53 PM, Lalith B notifications@github.com wrote:

yeah I tried --fit-width but the issue arised when turning the device to
landscape and portrait mode. The grey spaces will show up when turning the
devices.

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/30#issuecomment-9103599.

[lalith-b]

the pages when rotating the device must adjust to fit the screen's new width after rotation.

[coolwanglu]

I see, that sounds like a UI feature to me

On Wed, Oct 3, 2012 at 7:59 PM, Lalith B notifications@github.com wrote:

the pages when rotating the device must adjust to fit the screen's new
width after rotation.

—
Reply to this email directly or view it on GitHubhttps://github.com//issues/30#issuecomment-9103720.

[iapain]

@coolwanglu IMO single line key-value would be ideal for preset file e.g.

f=1
l=1
output-dir=~/Documents
space-as-offset=1

I can patch this if you want. I still don’t see it as top priority work.

Regarding Mobile devices @coolwanglu problem is not exactly with width and viewports. It's more related to memory optimization in iOS which degrades some features when memory warning is received. There are quite a few tricks to make it more responsive as mentioned here.

http://stackoverflow.com/questions/9941972/slow-list-view-scrolling-on-ipad-when-scrolling-in-an-overflowauto-div

@deathlord87 Based on my tests on iPad. I have found that scrolling is very laggy, rest all works with proper zoom option.

[lalith-b]

yes the scrolling is slow only because of the javascript. Try removing the jquery in manifest and run on iPad. Its better than the app with the jquery. i really dont understand what the javascript does.

About memory warnings. It's beacause of the scrollable div area as I've read. Thats why i suggested iscroll dont know if that will work either, its all about performance.

@iapain also try compiling the sources with loading the html with the following change in manifest.

<!body>
<!div id="pdf-main">

to

<!body id="pdf-main">

It loads a bit better. I will run performance tests with instruments in mac and give some ideas of memory peaks.