Prevent error checking on block during drag
Prevent error checking on block during drag

There was a visual glitch when dragging variable getters into sockets
due to the error icon appearing and shifting the block visually from
the coordinate Blockly maintained as the drag position. This resulted
in the connection highlight and checking algorithms to not fire when
the blocks were visually aligned but rather when the internal states
were visually aligned. This commit prevents checking a block for
errors if the block is being dragged. After the drag is complete, a
Move event will be triggered and the workspaceChanged listener will
perform an error check at the time the block is dropped. This prevents
an error icon from causing the aforementioned glitch.

Fixes #971

Change-Id: I225dac2a278b58dae9e520747a9f2c69c96bf109

kkashi01/appinventor-sources,jisqyv/appinventor-sources,mit-cml/appinventor-sources,josmas/app-inventor,marksherman/appinventor-sources,josmas/app-inventor,barreeeiroo/appinventor-sources,mit-cml/appinventor-sources,marksherman/appinventor-sources,mit-dig/punya,Klomi/appinventor-sources,jisqyv/appinventor-sources,halatmit/appinventor-sources,farxinu/appinventor-sources,RachaelT/appinventor-sources,jisqyv/appinventor-sources,barreeeiroo/appinventor-sources,CoderDojoLX/appinventor-sources,jisqyv/appinventor-sources,mit-dig/punya,puravidaapps/appinventor-sources,Klomi/appinventor-sources,marksherman/appinventor-sources,warren922/appinventor-sources,farxinu/appinventor-sources,barreeeiroo/appinventor-sources,puravidaapps/appinventor-sources,josmas/app-inventor,kkashi01/appinventor-sources,jisqyv/appinventor-sources,ewpatton/appinventor-sources,RachaelT/appinventor-sources,marksherman/appinventor-sources,farxinu/appinventor-sources,CoderDojoLX/appinventor-sources,josmas/app-inventor,RachaelT/appinventor-sources,ewpatton/appinventor-sources,kkashi01/appinventor-sources,mit-dig/punya,marksherman/appinventor-sources,warren922/appinventor-sources,warren922/appinventor-sources,mit-dig/punya,halatmit/appinventor-sources,farxinu/appinventor-sources,barreeeiroo/appinventor-sources,RachaelT/appinventor-sources,CoderDojoLX/appinventor-sources,mit-dig/punya,ewpatton/appinventor-sources,josmas/app-inventor,Klomi/appinventor-sources,halatmit/appinventor-sources,marksherman/appinventor-sources,warren922/appinventor-sources,farxinu/appinventor-sources,puravidaapps/appinventor-sources,halatmit/appinventor-sources,warren922/appinventor-sources,ewpatton/appinventor-sources,jisqyv/appinventor-sources,mit-dig/punya,puravidaapps/appinventor-sources,halatmit/appinventor-sources,josmas/app-inventor,halatmit/appinventor-sources,mit-cml/appinventor-sources,puravidaapps/appinventor-sources,CoderDojoLX/appinventor-sources,Klomi/appinventor-sources,ewpatton/appinventor-sources,ewpatton/appinventor-sources,kkashi01/appinventor-sources,mit-cml/appinventor-sources,kkashi01/appinventor-sources,mit-cml/appinventor-sources,RachaelT/appinventor-sources,kkashi01/appinventor-sources,barreeeiroo/appinventor-sources,mit-dig/punya,mit-cml/appinventor-sources,Klomi/appinventor-sources,CoderDojoLX/appinventor-sources