Scrawl-canvas v8 - Canvas test 036

Test purpose

Test Cell functionality - specifically their artefact-like behaviour:

• Create a range of Cell artefacts with absolute and relative positioning and dimensions
• Test that responsive Cell dimensions automatically update by dragging the visible <canvas> element's bottom right corner
• Pivot an entity to a Cell; mimic an entity to a Cell
• Pivot, mimic, path Cells to entitys
• Animate the Cells - for instance: delta roll; animate along a path
• Pivot a Cell to mouse cursor (tested separately in Demo DOM-011)
• Collision detection - for instance emulating mouse hover over a Cell
• Drag-and-drop a Cell across the canvas

Note that the base Cell will stamp all entitys assigned to it as part of its compile step in the Display cycle, but additional Cells do not get stamped onto the base until the show step - thus additional Cells always stamp on top of base Cell entitys.

To give a Cell a border, add a Block entity and mimic it to the Cell - making sure it mimics the Cell's start, handle, dimensions, scale and rotation while also adding its own dimensions (twice the value of the required border). Or vice versa - both methods are tested in the code.

Hover effects, and drag-and-drop, functionality for Cells has to be 'emulated' by setting up a Block entity to perform these actions then getting the Cell to mimic/pivot the Block.

Annotated code