Better handling of sizes when dropping contents

[mfreiholz]

Currently it's unpredictable. It might be good to use the same width/height as the parent content, if dropped on existing content. In case of outer-drop we might use the preferred size of the content.

Handle content drops (Sizing)

• Case: Dropping A to the bottom or top of B (vertical split):
  • A will use the width of B
  • A will use it's own height, if it is not greater than the half height of B. Otherwise it will use the half height of B.
• Case: Dropping A to the left or right of B (horizontal split)
  • ... Same as before, but swap the words "height" with "width" :-)
• Case: Dropping A to the outer top or bottom edge (full vertical split):
  • A will use the full width of the container
  • A will use it's own height, if it is not greater than the half height of the entire container. Otherwise it will use the half height of the container.
• Case: Dropping A to the outer left or right edge (full horizontal split):
  • ... Same as before, but swap the words "height" with "width" :-)