/** Do all of the recalculations needed when the data array changes. */
private void onDataChanged() {
int angle = 360 / mData.size();
// This is the extra degrees that cannot be equally divided by the number of sides
int extra = 360 % mData.size();
// When the data changes, we have to recalculate
// all of the angles.
int currentAngle = 0;
for (Item it : mData) {
// Adds the extra degrees to the last slice to ensue no gaps
if (mData.get(mData.size() - 1).mLabel.equals(it.mLabel)) {
it.mEndAngle = currentAngle + angle + extra;
} else {
it.mEndAngle = currentAngle + angle;
}
it.mStartAngle = currentAngle;
currentAngle = it.mEndAngle;
// Recalculate the gradient shaders. There are
// three values in this gradient, even though only
// two are necessary, in order to work around
// a bug in certain versions of the graphics engine
// that expects at least three values if the
// positions array is non-null.
//
it.mItemShader =
new SweepGradient(
mPieBounds.width() / 2.0f,
mPieBounds.height() / 2.0f,
new int[] {
it.mItemHighlight, it.mItemHighlight, it.mItemColor, it.mItemColor,
},
new float[] {
0,
(float) (360 - it.mEndAngle) / 360.0f,
(float) (360 - it.mStartAngle) / 360.0f,
1.0f
});
it.cSliceShader =
new SweepGradient(
mPieBounds.width() / 2.0f,
mPieBounds.height() / 2.0f,
new int[] {
it.cSliceHighlight, it.cSliceHighlight, it.cSliceColor, it.cSliceColor,
},
new float[] {
0,
(float) (360 - it.mEndAngle) / 360.0f,
(float) (360 - it.mStartAngle) / 360.0f,
1.0f
});
}
calcCurrentItem();
onScrollFinished();
}
