IPad: improve method to input position / size via pen / touch

[NotMyFault]

On iPad, it is extremely difficult to provide exact input via pen or mouse to 

• numeric input like radius for blur filter
• small numbers in the range of 0.0, 0.1, 0.2
• large numbers above 100

You are forced to switch to (display) keyboard which breaks the flow.

using keyboard doesn’t allow to give small increments, you need to type in the numbers from scratch. Using the delete key often produces erratic input (maybe depending on locale like German with has decimal and comma swapped).

One way to overcome this would be providing a scale preselector button:

• small: a pen or touch gesture will input numbers from 0.0 to 4.0 with steps of 0.1. A pen gesture like move to the left or right will cause a change of plus/minus 0.1 to allow fine level incremental input.
• normal: gestures will input numbers from 0.0 to 100.0 like today
• large: input allows to create numbers from 100.0 to a reasonable limit, e.g. 4000

The most important aspects are:

• data input while continuously using pen or touch (no keyboard),
• Allow small increments of 0.1 (or 0.01 depending on context)
• Allow increments of 1 and 10 using modifier keys (via touch interface), similar to shift / control / alt modifiers on Desktop with mouse scroll wheel