Figured it out!
This changes my row of buttons from a column to row based on the window ratio. Finally figured out windowBounds.height and windowBounds.width.
myPanel.onResizing = myPanel.onResize = function () { if (myPanel.windowBounds.height > myPanel.windowBounds.width){ myPanel.grp.cmds.orientation = "column"; } else { myPanel.grp.cmds.orientation = "row"; } this.layout.resize();
}