Modify dump string.
Refactoring.
Fix: widget cannot deleted and Refactoring.
Refactoring.
Refactoring.
Refactoring.
Enhancing toString.
Refactoring.
Refactoring.
Refactoring.
Remove creating shortcut issue.
Refactoring.
Modify string and version code.
Refactoring.
Refactoring.
fix: y axis lower after dropped
try multi-thread solution.
Refactoring duration 600 to ANIMATE_DURATION.
Refactoring duration 600 to ANIMATE_DURATION. Shorten DELAY_OUT for delete delay. y-axis issue. check all cells after drop.