Several common gestures consist of a repetitive, back and forth movement. Consider the following examples of this type of gesture:
Nodding (yes or I'm listening)
Shaking one's head (no or dismay)
Waving (a greeting)
Shaking hands (a greeting)
Shaking one's fist (a threat or a protest)
Wagging a finger (scolding)
Wiggling a finger or fingers (beckoning)
Tapping one's foot against the ground (impatience)
Tapping four fingers against a table (impatience)
Tapping two fingers against a table ("Thanks for the green tea")
Pacing (anxiety)
Jumping up and down (excitement, joy)
To help us recognize such gestures, let's write a class, BackAndForthGesture, which keeps track of the number of times that a value (such as an x coordinate or a y coordinate) has oscillated between a low threshold and a high threshold. A certain number of oscillations can be considered as a complete gesture.
Create a file, src/BackAndForthGesture.java. As a member variable, BackAndForthGesture will store...
