问题
Imagine a normal keyboard in android (like English). When pressing and holding A for a while, a new menu with á, ä and other buttons popups up. And while still holding the first finger down on screen, you slide it on top of another of those buttons. As you slide it over a button, it gets into highlighted mode , and when you slide out the highlighting is turned off. If you release the finger, the popup buttons disappear. If you held the finger over one of the buttons, that button's character is being typed into the text field
How can i achieve this functionality on andriod. Any help will be deeply apreciated.
来源：https://stackoverflow.com/questions/38178539/popup-keyboard-like-android-default-keyboard