I have chromium running in kiosk mode on a rasp pi 3. What do I need to do to add the onscreen keyboard and get it to auto hide and auto popup when text entry areas are selected inside the browser webpage? Is this possible? I have the 7" pi touchscreen and need to enter some text on a few of the pages. Mostly numbers. Can the keyboard popup when choosing an editable area on the webpage and autohide when the cursor is not in an editable text area? Just for Chromium.
If I understand what you want correctly I believe that a chrome extension is what you are look if for and would recommend that you look into something like this as it should satisfy all your requirements as it only does the keyboard when an input is selected.