Monkeybread Software - DynaPDF Manual

DynaPDF Manual - Page 27

Language Bindings

Page 27 of 821

The above settings are for Windows Forms Apps. Note that this is how it works today,

tomorrow you must maybe change other settings.

WPF and UWP apps come out of the box with high dpi support but using native code for UI

elements in WPF or UWP is difficult and not recommended. WPF and UWP apps function more

or less like a web site. When speed is no concern it is better use pure .Net code in these

environments.

Scrolling issues on high dpi devices

Scrolling issues are one of the major issues on high dpi devices. Almost every application scrolls

differently on Windows 10. Some scroll way to fast, others scroll too slow, and again others are

stuttering or have weird scroll behavior.

To make it even more complicated, every Windows 10 version has its own scroll issues. One of

the reasons why scrolling is so painful on Windows 10 is probably the lack of documentation.

No one really knows how scrolling can be implemented in a manner that works on low and

high dpi devices. The result is what we see today: almost all major web browsers use smooth

scrolling with different scroll speeds which are more or less useful, while normal applications

use arbitrary scroll techniques with a wide range of issues.

So, how to correctly implement device independent scrolling? I'm really sorry but I don't have

an answer.

I think the best way to avoid scrolling issues is to get users a chance to adjust the scrolling speed

in your application since the settings of the system are not helpful anymore.

If you use the rendering control of DynaPDF or the page cache then you can adjust the scroll

line delta with SetScrollLineDelta(). The example code of the viewer example tries to set this

value resolution independent as possible but it is usually best when the user has the ability to

change the value. Smooth scrolling is not yet supported.

Static contents in dpi aware applications

Something that must be considered when turning on high dpi support is that static contents like

the application icon or cursors must be delivered in different sizes since no scaling occurs.

Especially cursors are critical because an unscaled cursor made for Windows 7, for example,

becomes very small. Microsoft recommends to add at least icons and cursors for the resolutions

96, 120, 144, and 196 DPI for desktop apps. You'll find many tools in the internet which help to

create icons and curors in different sizes.