-There will be an app with two buttons and a drawing area.
-The app starts in edit mode. When the user places their ﬁnger on the drawing area they will be
able to draw a line. They place their ﬁnger on screen and slide their ﬁnger. The ﬁrst position the
ﬁnger touches will be the start of the line. As they slide their ﬁnger on the screen a line is
drawn from the start of the line to the current position of their ﬁnger. When they release their
ﬁnger the last position of the ﬁnger becomes the end point of the line. If the user starts (or
ends) a line very close (about 10 pixels) to the start or end of another line the new line starts
(ends) at the start or end of the other line. This will allow the user to draw shapes. The user
should be able to draw up to at least 10 lines.
-One of the buttons will be the "Clear" button. When pressed all lines drawn on the screen by
the user are erased.
-The other button is the "Go" button. When the "Go" button is pressed three things will happen:
1) the "Go" button will rotate 360 degrees clockwise.
2) the button label will change from "Go" to "Stop".
3) the app goes from edit mode to animation mode.
In animation mode the accelerometer will be turned on and as the user tilts the device the lines on the screen will move accordingly. That is the lines will move down based on the pull of gravity. As the user tilts or moves the phone the lines need to respond to changes in the accelerometer. (note: accelerometer give you acceleration not velocity). When the user presses on the button while the label is "Stop" the accelerometer is turned off, the lines stop moving, the button rotate 360 degrees counterclockwise, its label changes to "Go" and the app
is back in edit mode.
-When the user shakes the device when in edit mode the last line drawn is erased. When a line reaches the edge of the screen it will bounce. That is it will lose some velocity and take into account the angle it strikes the edge. For example if the line hits the edge at 90 degree angle it will bounce straight back. If it strikes the edge at a 45 degree angle it will bounce off at a 135 degree angle. Each line can have one velocity so when one end hits the edge the entire line bounces.
-Allow different ends of a line to move in different directions but still keep the line the same length.
Skills: drawing, velocity