Feature to add a background to Shared Notes activity

[sarthak-g]

Fixed #799

This new feature should:

• Add a new icon in the toolbar to select the background from the Journal
• Set the image as the background
• Handle resizing of the background image when the board is resized
• Handle record of the background image when the board is save in the Journal.

[llaske]

Nice.
But the background should be adapted to zoom and move.

[sarthak-g]

But the background should be adapted to zoom and move.

By this mean you mean, on zooming background should also be zoomed?

[llaske]

Yes and it should be set at the background position of the top/left of the board and move when the board is move. Using a background during a meeting is something usual, see for example here. Of course, the image resolution should have a good resolution.

[sarthak-g]

@llaske made required changes
Is this correct?

[llaske]

That's the idea but:

• The background should move when the canvas is moved. Currently only notes are moved
• The background sounds limited to initial size of the board whatever the zoom is. The idea is to zoom out, add a background image with a large size, then to zoom in so the background could cover several screen at normal size

Just a detail but the insert image button should be at the left of the remove button in the toolbar.

[sarthak-g]

Raised new pull request (#914 )