Putting It All Together
In the remainder of this chapter, we’ll implement the MathAnimation view, as well as a special surprise.
Insert the statements shown here in bold into the
MathAnimation.h
file:#import <Cocoa/Cocoa.h> @interface MathAnimation : NSView { float theta; // Current rotation for the star float fraction; // Current intensity for the pulsing icon float ddelta; // Density delta for icon NSMutableAttributedString *str; // "MathPaper" string NSImage *image; NSTimer *timer; // Our timer } - (IBAction)tick:(id)sender; @end
The purpose of these six instance variables is easier to understand
with the About panel from Figure 14-1 in mind, so
you might want to go back and take a quick look at it. The first
three variables, theta
,
fraction
, and ddelta
, will be
used to keep track of the animation’s rotation,
intensity, and density, respectively. They will be updated by NSTimer
methods as they are invoked. The NSMutableAttributedString variable
str
will be used to hold the attributed
“MathPaper” text.
We’ll create this string when the MathAnimation view
is first initialized, and then draw it on the view each time that we
are asked to draw the view. The same is true for the image held in
the NSImage instance variable, image
. Finally, the
NSTimer variable timer
will be used to keep track
of the timer. This timer is created when the window is exposed.
We need to keep the instance variable so
we can invalidate the timer when the window is closed.
Edit the file
MathAnimation.m ...
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