It is possible to select GUI.windows that are used in Editor Window with mouse left click. When clicked, these windows turn lighter color. See attached image from Unity documentation.
As it is possible to show one window as selected, I was thinking to use this for multi selection.
However I can’t seem to find a method for this, manual mouse click changes color, but method to do this from code seems to be non-existing - perhaps it is done with GUI skin / style or something else?
Do the rendering of boxes with window style: GUI.Box(box, “”, GUI.skin.window);
Render all the previous window contents to an area matching your box Rect.
This allows getting proper highlighting and you can manage without using beginWindows / EndWindows. If a box thing is selected, do GUI.backgroundColor with different color. If not, use default color. However, this solution has a little limitation - coloring can only be multiplicative AFAIK, so it doesn’t seem like I can get any “highlight” effect, only darken effect with some color or gray tones. Well at least it works better than window.
I didn’t bother checking if it is somehow possible to tamper with window style, I’ve so far used default GUI.skin.
