Thanks for you reply.
I'm not exactly developing a diagram view, but want to use your lib for the shapes, grid, document, view, layers and so on.
I've to build a sort of grid with a very big X-axis (~32000) and a 'normal Y-axis (~100). I've to write at the top of the column the id in the column (0 to 32000 / depending on the scale display or not). In y, scale always the same, and text at the left of the grid (e.g 'product 1').
Afterwards, I want to show the intersection between lines (product) and vertical ids with colored squares (editable, this is where your library is interesting me). Afterwards I will put some other objects also at intersection between lines en columns, using layers.
By the way, I've tried to create 32'000 texts in the column header, and it is pretty slow. Am I making something wrong (creating and adding each text to document) or perhaps 32'000 is definitively too much in term of objects in 1 document ?
I understand that I'm not using you diagrams exactly for what they are done, but I will have later on to implement also 'real' diagrams, so if I can use the same library ....