if your selection-tool is selected … you can temporarily select direct-selection-tool by clicking "a" key on keyboard. to return to selection-tool … click "v" key on keyboard. indiscriminately, by hovering your mouse[cursor] in front of each tool, keyboard-shortcut appears for that tool … i have found no single-click temporary alliance, such as what illustrator offers. turning this feature on … window/utilities/tool-hints … i tested this on both indd-cs6 as well as indd-cc2018 … thanks.