Deck 7: Touches and Swipes

Question 1

Touching the screen can be detected on Android devices.

Answer 1

True

Question 2

To handle touch events, one of the things we must do is define a class that implements View.OnTouchListener and overrides its ____________ method.

Answer 2

onTouch

Question 3

The public field of the ViewGroup.MarginLayoutParams class defining a right margin is ____________.

Answer 3

rightMargin

Question 4

The onTouch method on View.OnTouchListener has this API:
boolean onTouch( View v, MotionEvent event )
The second parameter, v, represents the current touch event.

Question 5

The rgb ____________ method of the Color class can be used to create a Color.

Question 6

It is possible that two Views overlap, in which case one View is stacked above the other View.

Question 7

The onSingleTapUp method of the GestureDetector.OnGestureListener interface is called on a(n) ____________ action when a touch occurs.

Question 8

It is possible for a device to detect taps.

Question 9

Which method of the GestureDetector class should we call from the onTouchEvent method of the Activity class to dispatch a touch event to the appropriate method of the listener interfaces?

A) onTouchEvent
B) onDispatch
C) dispatch
D) callListener

Question 10

It is possible to adjust the font size of a TextView depending on the text contained inside the TextView.

Question 11

What does the getRawX method of MouseEvent return?

A) The x coordinate of the touch within the screen
B) The x coordinate of the touch within the View where the touch happened
C) The x coordinate of the top of the screen
D) The x coordinate of the top of the View where the touch happened

Question 12

What does the getAction method of MouseEvent return?

A) A double
B) A float
C) An int, the x coordinate of the touch within the screen
D) An int, representing the type of action that occurred

Question 13

We want to be able to compare the starting coordinate of a touch with the ending coordinate of a touch. How can we do it?

A) We cannot compare those coordinates.
B) We can compare them inside the onTouch method when it is called; nothing additional needed.
C) Store the ending coordinate in an instance variable and compare it to the starting coordinate of the touch inside the onTouch method.
D) Store the starting coordinate in an instance variable and compare it to the ending coordinate of the touch inside the onTouch method.

Question 14

The getX method of MouseEvent returns:

A) the x coordinate of the touch within the screen.
B) the x coordinate of the touch within the View where the touch occurred.
C) the x coordinate of the top of the screen.
D) the x coordinate of the top of the View where the touch occurred.

Question 15

We can enable the user to move a TextView.

Question 16

One of the things we must do to handle touch events is create an object of a class that __________________ View.OnTouchListener.

Question 17

One of the things we must do to handle touch events is register an object of a class that implements View.OnTouchListener on one or more __________________.

Question 18

The public field of the ViewGroup.MarginLayoutParams class defining a bottom margin is __________________.

Question 19

The public field of the ViewGroup.MarginLayoutParams class defining a top margin is __________________.

Question 20

The __________________ interface notifies us of double taps or confirmed single taps.

Question 21

The onDown method of the GestureDetector.OnGestureListener interface is called on a(n) __________________ action when a touch occurs.

Question 22

If a TextView has not been displayed yet, it is possible to retrieve measurements about its width and height using the __________________ method.