We human being have our fingers, but we seem more familiar with mouse. That's easy to catch up because mouse has been used over 30 years somehow for us to manipulate computers. With finger, not more than 10 years, maybe only 5 years?
For programmers who come from PC days, most of the GUI works are to handle the callbacks for MouseDown, MouseMove and MouseUp. It is a nature way to abstract those actions as PointerStarted, PointerMoving and PointerEnd when the touch events have to be taken into account. However, a most important difference for mouse and finger is it is possible for mouse to move without the button pressed . For finger, can you ?
We should be aware of this a little bit earlier! But we are stupid so much until mistake has been there.
In recent version, we offered the measure tools into the viewer. For demo purpose, only ruler and protractor are provided. From software engineering's perspective, set up an elegant framework to easily add any type of measure tools is of great challenge. There won't be much of coding efforts, but it really needs good understanding on object-orient theory. (In fact,
you can find many tutorials or OO books are using measure tools as example to teach programming. ) Fortunately, We went through the design and released the ruler and protractor somehow. It works not bad on our desktop. However, it is not case any more when We took the testing on the mobile device. I forgot the fact that touch moving won't have the press down accompanied. The consequence is it looks wired for the manipulation style of measurement. Sometimes it looks anti-intuitive!
So , Be Caution, don't try the ruler and protractor on mobile device before we fix the bugs. We'll be back soon.