创建自定义控件2-自定义绘制

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

private void init() {
mTextPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mTextPaint.setColor(mTextColor);
if (mTextHeight == 0) {
mTextHeight = mTextPaint.getTextSize();
} else {
mTextPaint.setTextSize(mTextHeight);
}

mPiePaint = new Paint(Paint.ANTI_ALIAS_FLAG);
mPiePaint.setStyle(Paint.Style.FILL);
mPiePaint.setTextSize(mTextHeight);

mShadowPaint = new Paint(0);
mShadowPaint.setColor(0xff101010);
mShadowPaint.setMaskFilter(new BlurMaskFilter(8, BlurMaskFilter.Blur.NORMAL));

...

1
2
3
4
5
6
7
8
9
10
11
12

// Account for padding
float xpad = (float)(getPaddingLeft() + getPaddingRight());
float ypad = (float)(getPaddingTop() + getPaddingBottom());

// Account for the label
if (mShowText) xpad += mTextWidth;

float ww = (float)w - xpad;
float hh = (float)h - ypad;

// Figure out how big we can make the pie.
float diameter = Math.min(ww, hh);

1
2
3
4
5
6
7
8
9
10
11
12
13

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
// Try for a width based on our minimum
int minw = getPaddingLeft() + getPaddingRight() + getSuggestedMinimumWidth();
int w = resolveSizeAndState(minw, widthMeasureSpec, 1);

// Whatever the width ends up being, ask for a height that would let the pie
// get as big as it can
int minh = MeasureSpec.getSize(w) - (int)mTextWidth + getPaddingBottom() + getPaddingTop();
int h = resolveSizeAndState(MeasureSpec.getSize(w) - (int)mTextWidth, heightMeasureSpec, 0);

setMeasuredDimension(w, h);
}

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26

protected void onDraw(Canvas canvas) {
super.onDraw(canvas);

// Draw the shadow
canvas.drawOval(
mShadowBounds,
mShadowPaint
);

// Draw the label text
canvas.drawText(mData.get(mCurrentItem).mLabel, mTextX, mTextY, mTextPaint);

// Draw the pie slices
for (int i = 0; i < mData.size(); ++i) {
Item it = mData.get(i);
mPiePaint.setShader(it.mShader);
canvas.drawArc(mBounds,
360 - it.mEndAngle,
it.mEndAngle - it.mStartAngle,
true, mPiePaint);
}

// Draw the pointer
canvas.drawLine(mTextX, mPointerY, mPointerX, mPointerY, mTextPaint);
canvas.drawCircle(mPointerX, mPointerY, mPointerSize, mTextPaint);
}