Description

Improves the drag and drop capabilities of the editor.

In particular:

• Adds a new DraggingTextRenderer that renders text into itself using knowledge of existing text layout to match text while being dragged.
• Overrides drag and drop methods on the text view to correctly support the gesture.
• Moves line fragment drawing logic into the LineFragment class instead of LineFragmentView to enable drawing contents into whatever drawing target is necessary.

Related Issues

• closes ✨ Drag and Drop Selected Text #42

Checklist

TODO:

• Drag text without background
• Cursor updates to indicate drag destination location.
• Modifier flags
  • Hold option to copy instead of cut
  • Escape to cancel
• I read and understood the contributing guide as well as the code of conduct
• The issues this PR addresses are related to each other
• My changes generate no new warnings
• My code builds and runs on my machine
• My changes are all related to the related issue above
• I documented my code

Screenshots