The splitview around the pdfviews is subview of the main splitview, so use the frame of that when changing splitview sizes.
The splitview around the pdfviews is subview of the main splitview, so use the frame of that when changing splitview sizes.

JackieXie168/skim,JackieXie168/skim,JackieXie168/skim,JackieXie168/skim,JackieXie168/skim