Previously EraseTool would only let you have hard lines, similar
to PenTool. After inheriting from BrushTool in previous commits,
making the eraser (optionally) behave like a brush is much easier.
We only need to change how the colors are handled for the hardness,
which is why the `draw_point()` call is a bit more involved. Just
blending the colors doesn't work here since we actually want to
replace the previous color, unlike in BrushTool where we are just
layering the color on top.
This removes all the code to handle events that was essentially
duplicated from BrushTool anyway :^)
I've also renamed "thickness"->"size" to have consistent
terminology.
Some tools (e.g. ZoomTool) doesn't need layer to work. This commit
makes mouse events fire even if there is no layer. This fixes
a bug that ZoomTool didn't work when there is no layers.
This commit adds a Tool::MouseEvent struct, which contains events that
may be needed by tools: layer-relative, image-relative and raw (editor-
relative) event.
The raw event is used by ZoomTool to properly pan the view. This fixes
a bug which caused image to snap out of sight.
This adds a tooltip to all the slider properties showing their
current value. Previously there was no indication of what
value they had. Also rename the SprayTool property 'thickness' to
'size' like BrushTool calls it.
SPDX License Identifiers are a more compact / standardized
way of representing file license information.
See: https://spdx.dev/resources/use/#identifiers
This was done with the `ambr` search and replace tool.
ambr --no-parent-ignore --key-from-file --rep-from-file key.txt rep.txt *
