EditingWidget redesign about mapsui

[inforithmics]

I agree with most points.

I think the GetAlternateMode() would solve the Editing Problems on Mobile/Touch Platforms.

There could be a Property that tells if the GetAlternateMode is supported in the platform and if not an Alternate Mode Button is displayed in the Editing Widget.

Or there could be a Property For displaying the AlternateModeButton on Mobile Platforms this is initially true. If it is set to false the GetAlternateMode Function needs to be implemented when it isn't implemented it throws an exception.

[pauldendulk]

@inforithmics I have been in submarine-mode in the previous weeks, focusing on manipulation (touch and mouse) and tackling anything that got in my way. The situation has completely change to when I wrote this post initially.

Some remarks:

• The EditingWidget should not have priority but for the work on manipulation it served as a very useful testcase. It was problematic because the old manipulation implementation was problematic. I made the EditingWidget usable on all platforms, also with touch.
• GetShiftState is now a method that needs to be implemented on all platforms (because it is called from the shared code, and it would not compile without). The implementation was not fixed yet. I think we should fix it because for mouse users this is really helpful. This means we need to start tracking key state on those platforms.
• Above I mentioned not supporting double click because it was entangle with platform specifics and did not function the same way on all platforms. This situation has changed, in main there is now a shared TapGestureTracker which is used on all platforms. It also detects double tap. And it may also implement long press. It is an isolated part of the code so easy to implement it, without the need for platform knowledge.
• In general I am very happy with how the manipulations turned out. We have three trackers: TapGestureTracker, FlingTracker (not really looked at that, could perhaps be improved, but it works) and the ManipulationTracker. That last one isolates a lot of previously very complicated things. Now you just call it with an array of all the contact positions, and it then calls Navigator.Manipulate with a Manipulation state parameter: _manipulationTracker.Manipulate(positions, Map.Navigator.Manipulate);, we do not need to distinguish between a drag and pinch mode.
• Now that we have double tap it becomes possible to use the EditingWidget on mobile.
• I think we should not add GetAlternateMode to the MapControl or eventArgs. If anything it should be a state in the EditingWidget itself. Actually we already have buttons used in the EditingWidget that change state, they are used in the main Editing sample.
• If we implement GetShiftState it might also become logical to go all the way with the modifier keys.

[pauldendulk]

I created to new issues and will close this one.
#2575
#2576