[Feature] Add Sankore drawing tool

[letsfindaway]

There were several requests to add the drawing tools from OpenSankoe to OpenBoard. I now tried to add the relevant classes to OpenBoard on top of the dev branch. My efforts are on the branch add-sankore-drawing-tool.

The first commits add the item classes and GUI classes. I have created subdirectories shape below domain and gui to separate these classes. The code is compile clean after each commit.

I then enabled the drawing palette and fixed a problem during resizing of shapes. Still a lot of work has to be done. The selection of shapes is not working, which affects the styling of lines, colors and fill colors. And serialization of shapes is completely missing.

The new code is protected by an #ifdef ENABLE_SHAPES. A configuration option is still missing.

The new classes are currently only added to the CMake build system and not to the qmake project files.

This branch is in a very preliminary state, but it already shows, that there are only a limited number of contact points to the core code. It seems to be possible to add the drawing tools without too many changes to the existing code base.

[kaamui]

Hi, I didn't see that you had already started to work on this ^^

I'd like to say that from my pov, the UI we made back then is quite poor, not intuitive at all, and a lot of improvement should be done in this regard. I even wonder how it should be presented in the app. Is it really a stylus tool ? Is there a better way to make it accessible ?

I wonder what are your thoughts on it.

[letsfindaway]

I wonder what are your thoughts on it.

Currently no. I'm just in the stage where I discover the features! Next would be how you apply the styles to the shapes. This currently does not work because selection of such objects does not work. And I just found out that you toggle between two selection modes, one with the delegate frame and another with the resize handles.

Of course the icons are not ideal, but besides that I first wanted to get the features working before changing much. And with minimal coupling to existing code. E.g. when it comes to persisting the shapes I think about just adding some signals to the UBSvgSubsetAdaptor which are fired when it recognizes something it cannot process. A class from the drawing tools can then connect and try to handle it. You took a similar approach to forward mouse events to the drawing tools.