一個很酷的加載loading效果,自定義LeafLoadingView實現,LeafLoadingView繼承view,
本例子主要由如下幾點構成
(1):RotateAnimation實現葉子旋轉
(2):葉子飄動
(3):當前進度繪製當前進度條
大致實現:
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);html
// 繪製進度條和葉子
// 之因此把葉子放在進度條裏繪製,主要是層級緣由
drawProgressAndLeafs(canvas);
// drawLeafs(canvas);android
canvas.drawBitmap(mOuterBitmap, mOuterSrcRect, mOuterDestRect, mBitmapPaint);ios
postInvalidate();
}canvas
private void drawProgressAndLeafs(Canvas canvas) {網絡
if (mProgress >= TOTAL_PROGRESS) {
mProgress = 0;
}
// mProgressWidth爲進度條的寬度,根據當前進度算出進度條的位置
mCurrentProgressPosition = mProgressWidth * mProgress / TOTAL_PROGRESS;
// 即當前位置在圖中所示1範圍內
if (mCurrentProgressPosition < mArcRadius) {
Log.i(TAG, "mProgress = " + mProgress + "---mCurrentProgressPosition = "
+ mCurrentProgressPosition
+ "--mArcProgressWidth" + mArcRadius);
// 1.繪製白色ARC,繪製orange ARC
// 2.繪製白色矩形app
// 1.繪製白色ARC
canvas.drawArc(mArcRectF, 90, 180, false, mWhitePaint);ide
// 2.繪製白色矩形
mWhiteRectF.left = mArcRightLocation;
canvas.drawRect(mWhiteRectF, mWhitePaint);post
// 繪製葉子
drawLeafs(canvas);動畫
// 3.繪製棕色 ARC
// 單邊角度
int angle = (int) Math.toDegrees(Math.acos((mArcRadius - mCurrentProgressPosition)
/ (float) mArcRadius));
// 起始的位置
int startAngle = 180 - angle;
// 掃過的角度
int sweepAngle = 2 * angle;
Log.i(TAG, "startAngle = " + startAngle);
canvas.drawArc(mArcRectF, startAngle, sweepAngle, false, mOrangePaint);
} else {
Log.i(TAG, "mProgress = " + mProgress + "---transfer-----mCurrentProgressPosition = "
+ mCurrentProgressPosition
+ "--mArcProgressWidth" + mArcRadius);
// 1.繪製white RECT
// 2.繪製Orange ARC
// 3.繪製orange RECT
// 這個層級進行繪製能讓葉子感受是融入棕色進度條中spa
// 1.繪製white RECT
mWhiteRectF.left = mCurrentProgressPosition;
canvas.drawRect(mWhiteRectF, mWhitePaint);
// 繪製葉子
drawLeafs(canvas);
// 2.繪製Orange ARC
canvas.drawArc(mArcRectF, 90, 180, false, mOrangePaint);
// 3.繪製orange RECT
mOrangeRectF.left = mArcRightLocation;
mOrangeRectF.right = mCurrentProgressPosition;
canvas.drawRect(mOrangeRectF, mOrangePaint);
}
}
/**
* 繪製葉子
*
* @param canvas
*/
private void drawLeafs(Canvas canvas) {
mLeafRotateTime = mLeafRotateTime <= 0 ? LEAF_ROTATE_TIME : mLeafRotateTime;
long currentTime = System.currentTimeMillis();
for (int i = 0; i < mLeafInfos.size(); i++) {
Leaf leaf = mLeafInfos.get(i);
if (currentTime > leaf.startTime && leaf.startTime != 0) {
// 繪製葉子--根據葉子的類型和當前時間得出葉子的(x,y)
getLeafLocation(leaf, currentTime);
// 根據時間計算旋轉角度
canvas.save();
// 經過Matrix控制葉子旋轉
Matrix matrix = new Matrix();
float transX = mLeftMargin + leaf.x;
float transY = mLeftMargin + leaf.y;
Log.i(TAG, "left.x = " + leaf.x + "--leaf.y=" + leaf.y);
matrix.postTranslate(transX, transY);
// 經過時間關聯旋轉角度,則能夠直接經過修改LEAF_ROTATE_TIME調節葉子旋轉快慢
float rotateFraction = ((currentTime - leaf.startTime) % mLeafRotateTime)
/ (float) mLeafRotateTime;
int angle = (int) (rotateFraction * 360);
// 根據葉子旋轉方向肯定葉子旋轉角度
int rotate = leaf.rotateDirection == 0 ? angle + leaf.rotateAngle : -angle
+ leaf.rotateAngle;
matrix.postRotate(rotate, transX
+ mLeafWidth / 2, transY + mLeafHeight / 2);
canvas.drawBitmap(mLeafBitmap, matrix, mBitmapPaint);
canvas.restore();
} else {
continue;
}
}
}