Pointer Support - Apply coordinate change from browser context to canvas positioning

[itsjamie]

The current issue is that a user can use collision: true to get if an element is "clicked" but they cannot use this simple event if they wish to know where an item was pressed with the pointer.

The real world case that required us to move outside the pointer API provided by Lightning was a progress bar for player controls supported on LG Smart TVs.

If you wanted to support clicking to seek to a position, there wasn't a good way to know from the provided interface where a user had clicked on a component with collision enabled.

The proposed extension to the API would ideally:

• convert from browser coordinates to:
  • canvas space
  • component space

[erikhaandrikman]

There is PR available: #506

example implementation:

Lightning/examples/mouse-pointer/basic-usage.html

Line 49 in d8f76b8

_handleClick(el, { x, y }) {