基于ArcSeekBar(圆弧拖动条)的修改
原作者地址：ArcSeekBar(圆弧拖动条)
原作者的效果是这样的。
我的需求是 移动滑块，前景色要变动。
我看到作者的GitHub上，也有人提这样的需求。
于是我自己在原作者的基础上，进行了二次修改
先放效果图：
前景色渐变 + 跟着滑块一起动。
背景色渐变 + 静止
废话不多说，直接上代码。
ArcSeekBar.java
/**
* 作用: 圆弧形 SeekBar
* 作者: GcsSloop
* 摘要: 该 SeekBar 实现的核心原理非常简单,其绘制内容实际上为一个圆弧,只用了一条 Path,
* 尽管核心原理简单,但仍有以下细节需要进行注意:
* 1. 画布旋转导致的坐标系问题.
* - 为了让开口方向可控,并且实现起来简单,进行了画布旋转,因此实际显示的坐标系下的坐标和绘制坐标系坐标是不同的,尤其需要注意.
* 2.当前进度确定问题
* - 进度是由角度确定的, 先根据当前点击位置和中心点连线与水平线的夹角表示当前角度,
* - 根据该角度和实际圆弧的角度相关信息推算出当前进度百分比.
* - 根据百分比和最大数值确定当前实际的进度.
* 3. 拖动与点击
* - 为了防止误触, 只有手指按下位置在拖动按钮附近时才可以执行拖动.
* - 但是用户单击时,可以可以直接跳转进度, 当然,只有点击在圆弧进度条的区域内才允许设置新的进度.
* - 如何判断是否点击在圆弧区域内,使用了 Region 的相关方法,该 Region 区域是从 Paint 的 getFillPath 得到的.
* 4. 进度回调去重
* - 用户拖动时,判断是否和上次进度相同,如果相同,则不发送回调.
* 5. 防止突变
* - 由于进度条时圆弧形状的,因此进度可能会从 0.0 直接突变到 1.0 或者相反,因此在计算进度与当前进度差异过大时,禁止改变当前进度.
*/
public class ArcSeekBar extends View {
private static final int DEFAULT_EDGE_LENGTH = 250; // 默认宽高
private static final float CIRCLE_ANGLE = 360; // 圆周角
private static final int DEFAULT_ARC_WIDTH = 40; // 默认宽度 dp
private static final float DEFAULT_OPEN_ANGLE = 120; // 开口角度
private static final float DEFAULT_ROTATE_ANGLE = 90; // 旋转角度
private static final int DEFAULT_BORDER_WIDTH = 0; // 默认描边宽度
private static final int DEFAULT_BORDER_COLOR = 0xffffffff; // 默认描边颜色
private static final int DEFAULT_THUMB_COLOR = 0xffffffff; // 拖动按钮颜色
private static final int DEFAULT_THUMB_WIDTH = 2; // 拖动按钮描边宽度 dp
private static final int DEFAULT_THUMB_RADIUS = 15; // 拖动按钮半径 dp
private static final int DEFAULT_THUMB_SHADOW_RADIUS = 0; // 拖动按钮阴影半径 dp
private static final int DEFAULT_THUMB_SHADOW_COLOR = 0xFF000000; // 拖动按钮阴影颜色
private static final int DEFAULT_SHADOW_RADIUS = 0; // 默认阴影半径 dp
private static final int THUMB_MODE_STROKE = 0; // 拖动按钮模式 - 描边
private static final int THUMB_MODE_FILL = 1; // 拖动按钮模式 - 填充
private static final int THUMB_MODE_FILL_STROKE = 2; // 拖动按钮模式 - 填充+描边
private static final int DEFAULT_MAX_VALUE = 100; // 默认最大数值
private static final int DEFAULT_MIN_VALUE = 0; // 默认最小数值
private static final String KEY_PROGRESS_PRESENT = "PRESENT"; // 用于存储和获取当前百分比
// 可配置数据
private int[] mArcColors; // Seek 颜色
private int[] mProgressColors; // progress的颜色
private float mArcWidth; // Seek 宽度
private float mOpenAngle; // 开口的角度大小 0 - 360
private float mRotateAngle; // 旋转角度
private int mBorderWidth; // 描边宽度
private int mBorderColor; // 描边颜色
private int mThumbColor; // 拖动按钮颜色
private float mThumbWidth; // 拖动按钮宽度
private float mThumbRadius; // 拖动按钮半径
private float mThumbShadowRadius;// 拖动按钮阴影半径
private int mThumbShadowColor;// 拖动按钮阴影颜色
private int mThumbMode; // 拖动按钮模式
private int mShadowRadius; // 阴影半径
private int mMaxValue; // 最大数值
private int mMinValue; // 最小数值
private int progress; // 进度值
private float mCenterX; // 圆弧 SeekBar 中心点 X
private float mCenterY; // 圆弧 SeekBar 中心点 Y
private float mThumbX; // 拖动按钮 中心点 X
private float mThumbY; // 拖动按钮 中心点 Y
private int mOffsetX; //偏移量 X
private int mOffsetY; //偏移量 Y
private Path mSeekPath; // seekBar 绘制路径
private Path mProgressPath; // seekBar progress 绘制路径
private Path mBorderPath;
private Paint mArcPaint;
private Paint mProgressPaint; // seekBar progress 画笔
private Paint mThumbPaint;
private Paint mBorderPaint;
private Paint mShadowPaint;
private RectF content;
private float[] mTempPos;
private float[] mTempTan;
private PathMeasure mSeekPathMeasure;
private PathMeasure mProgressPathMeasure;
private float mProgressPresent = 0; // 当前进度百分比
private boolean mCanDrag = false; // 是否允许拖动
private boolean mAllowTouchSkip = false; // 是否允许越过边界
private GestureDetector mDetector;
private Matrix mInvertMatrix; // 逆向 Matrix, 用于计算触摸坐标和绘制坐标的转换
private Region mArcRegion; // ArcPath的实际区域大小,用于判定单击事件
public ArcSeekBar(Context context) {
this(context, null);
}
public ArcSeekBar(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public ArcSeekBar(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
setSaveEnabled(true);
setLayerType(LAYER_TYPE_SOFTWARE, null);
initAttrs(context, attrs);
initPaint();
initData();
}
//--- 初始化 -----------------------------------------------------------------------------------
// 初始化各种属性
private void initAttrs(Context context, AttributeSet attrs) {
TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.ArcSeekBar);
mArcColors = getArcColors(context, ta);
mProgressColors = getProgressColors(context, ta);
mArcWidth = ta.getDimensionPixelSize(R.styleable.ArcSeekBar_arc_width, dp2px(DEFAULT_ARC_WIDTH));
mOpenAngle = ta.getFloat(R.styleable.ArcSeekBar_arc_open_angle, DEFAULT_OPEN_ANGLE);
mRotateAngle = ta.getFloat(R.styleable.ArcSeekBar_arc_rotate_angle, DEFAULT_ROTATE_ANGLE);
mMaxValue = ta.getInt(R.styleable.ArcSeekBar_arc_max, DEFAULT_MAX_VALUE);
mMinValue = ta.getInt(R.styleable.ArcSeekBar_arc_min, DEFAULT_MIN_VALUE);
// 如果用户设置的最大值和最小值不合理，则直接按照默认进行处理
if (mMaxValue <= mMinValue) {
mMaxValue = DEFAULT_MAX_VALUE;
mMinValue = DEFAULT_MIN_VALUE;
}
progress = ta.getInt(R.styleable.ArcSeekBar_arc_progress, mMinValue);
mBorderWidth = ta.getDimensionPixelSize(R.styleable.ArcSeekBar_arc_border_width, dp2px(DEFAULT_BORDER_WIDTH));
mBorderColor = ta.getColor(R.styleable.ArcSeekBar_arc_border_color, DEFAULT_BORDER_COLOR);
mThumbColor = ta.getColor(R.styleable.ArcSeekBar_arc_thumb_color, DEFAULT_THUMB_COLOR);
mThumbRadius = ta.getDimensionPixelSize(R.styleable.ArcSeekBar_arc_thumb_radius, dp2px(DEFAULT_THUMB_RADIUS));
mThumbShadowRadius = ta.getDimensionPixelSize(R.styleable.ArcSeekBar_arc_thumb_shadow_radius, dp2px(DEFAULT_THUMB_SHADOW_RADIUS));
mThumbShadowColor = ta.getColor(R.styleable.ArcSeekBar_arc_thumb_shadow_color, DEFAULT_THUMB_SHADOW_COLOR);
mThumbWidth = ta.getDimensionPixelSize(R.styleable.ArcSeekBar_arc_thumb_width, dp2px(DEFAULT_THUMB_WIDTH));
mThumbMode = ta.getInt(R.styleable.ArcSeekBar_arc_thumb_mode, THUMB_MODE_STROKE);
mShadowRadius = ta.getDimensionPixelSize(R.styleable.ArcSeekBar_arc_shadow_radius, dp2px(DEFAULT_SHADOW_RADIUS));
mOffsetX = ta.getInt(R.styleable.ArcSeekBar_arc_offset_x, 0);
mOffsetY = ta.getInt(R.styleable.ArcSeekBar_arc_offset_y, 0);
ta.recycle();
}
// 获取 Arc 颜色数组
private int[] getArcColors(Context context, TypedArray ta) {
int[] ret;
int resId = ta.getResourceId(R.styleable.ArcSeekBar_arc_progress_background, 0);
if (0 == resId) {
resId = R.array.arc_colors_default;
}
ret = getColorsByArrayResId(context, resId);
return ret;
}
private int[] getProgressColors(Context context, TypedArray ta) {
int[] ret;
int resId = ta.getResourceId(R.styleable.ArcSeekBar_arc_progress_front, 0);
if (0 == resId) {
resId = R.array.arc_colors_default;
}
ret = getColorsByArrayResId(context, resId);
return ret;
}
// 根据 resId 获取颜色数组
private int[] getColorsByArrayResId(Context context, int resId) {
int[] ret;
TypedArray colorArray = context.getResources().obtainTypedArray(resId);
ret = new int[colorArray.length()];
for (int i = 0; i < colorArray.length(); i++) {
ret[i] = colorArray.getColor(i, 0);
}
return ret;
}
// 初始化数据
private void initData() {
mSeekPath = new Path();
mProgressPath = new Path();
mBorderPath = new Path();
mSeekPathMeasure = new PathMeasure();
mProgressPathMeasure = new PathMeasure();
mTempPos = new float[2];
mTempTan = new float[2];
mDetector = new GestureDetector(getContext(), new OnClickListener());
mInvertMatrix = new Matrix();
mArcRegion = new Region();
setProgress(getProgress());
}
// 初始化画笔
private void initPaint() {
initArcPaint();
initProgressPaint();
initThumbPaint();
initBorderPaint();
initShadowPaint();
}
// 初始化圆弧画笔
private void initArcPaint() {
mArcPaint = new Paint();
mArcPaint.setAntiAlias(true);
mArcPaint.setStrokeWidth(mArcWidth);
mArcPaint.setStyle(Paint.Style.STROKE);
mArcPaint.setStrokeCap(Paint.Cap.ROUND);
}
private void initProgressPaint() {
mProgressPaint = new Paint();
mProgressPaint.setAntiAlias(true);
mProgressPaint.setStrokeWidth(mArcWidth);
mProgressPaint.setStyle(Paint.Style.STROKE);
mProgressPaint.setStrokeCap(Paint.Cap.ROUND);
}
// 初始化拖动按钮画笔
private void initThumbPaint() {
mThumbPaint = new Paint();
mThumbPaint.setAntiAlias(true);
mThumbPaint.setColor(mThumbColor);
mThumbPaint.setStrokeWidth(mThumbWidth);
mThumbPaint.setStrokeCap(Paint.Cap.ROUND);
if (mThumbMode == THUMB_MODE_FILL) {
mThumbPaint.setStyle(Paint.Style.FILL_AND_STROKE);
} else if (mThumbMode == THUMB_MODE_FILL_STROKE) {
mThumbPaint.setStyle(Paint.Style.FILL_AND_STROKE);
} else {
mThumbPaint.setStyle(Paint.Style.STROKE);
}
mThumbPaint.setTextSize(56);
}
// 初始化拖动按钮画笔
private void initBorderPaint() {
mBorderPaint = new Paint();
mBorderPaint.setAntiAlias(true);
mBorderPaint.setColor(mBorderColor);
mBorderPaint.setStrokeWidth(mBorderWidth);
mBorderPaint.setStyle(Paint.Style.STROKE);
}
// 初始化阴影画笔
private void initShadowPaint() {
mShadowPaint = new Paint();
mShadowPaint.setAntiAlias(true);
mShadowPaint.setStrokeWidth(mBorderWidth);
mShadowPaint.setStyle(Paint.Style.FILL_AND_STROKE);
}
//--- 初始化结束 -------------------------------------------------------------------------------
//--- 状态存储 ---------------------------------------------------------------------------------
@Override
protected Parcelable onSaveInstanceState() {
Bundle bundle = new Bundle();
bundle.putParcelable("superState", super.onSaveInstanceState());
bundle.putFloat(KEY_PROGRESS_PRESENT, mProgressPresent);
return bundle;
}
@Override
protected void onRestoreInstanceState(Parcelable state) {
if (state instanceof Bundle) {
Bundle bundle = (Bundle) state;
this.mProgressPresent = bundle.getFloat(KEY_PROGRESS_PRESENT);
state = bundle.getParcelable("superState");
}
if (null != mOnProgressChangeListener) {
mOnProgressChangeListener.onProgressChanged(this, getProgress(), false);
}
super.onRestoreInstanceState(state);
}
//--- 状态存储结束 -----------------------------------------------------------------------------
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
int ws = MeasureSpec.getSize(widthMeasureSpec); //取出宽度的确切数值
int wm = MeasureSpec.getMode(widthMeasureSpec); //取出宽度的测量模式
int hs = MeasureSpec.getSize(heightMeasureSpec); //取出高度的确切数值
int hm = MeasureSpec.getMode(heightMeasureSpec); //取出高度的测量模
if (wm == MeasureSpec.UNSPECIFIED) {
wm = MeasureSpec.EXACTLY;
ws = dp2px(DEFAULT_EDGE_LENGTH);
} else if (wm == MeasureSpec.AT_MOST) {
wm = MeasureSpec.EXACTLY;
ws = Math.min(dp2px(DEFAULT_EDGE_LENGTH), ws);
}
if (hm == MeasureSpec.UNSPECIFIED) {
hm = MeasureSpec.EXACTLY;
hs = dp2px(DEFAULT_EDGE_LENGTH);
} else if (hm == MeasureSpec.AT_MOST) {
hm = MeasureSpec.EXACTLY;
hs = Math.min(dp2px(DEFAULT_EDGE_LENGTH), hs);
}
setMeasuredDimension(MeasureSpec.makeMeasureSpec(ws, wm), MeasureSpec.makeMeasureSpec(hs, hm));
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
// 计算在当前大小下,内容应该显示的大小和起始位置
int safeW = w - getPaddingLeft() - getPaddingRight();
int safeH = h - getPaddingTop() - getPaddingBottom();
float edgeLength, startX, startY;
float fix = mArcWidth / 2 + mBorderWidth + mShadowRadius * 2; // 修正距离,画笔宽度的修正
if (safeW < safeH) {
// 宽度小于高度,以宽度为准
edgeLength = safeW - fix;
startX = getPaddingLeft();
startY = (safeH - safeW) / 2.0f + getPaddingTop();
} else {
// 宽度大于高度,以高度为准
edgeLength = safeH - fix;
startX = (safeW - safeH) / 2.0f + getPaddingLeft();
startY = getPaddingTop();
}
// 得到显示区域和中心的
content = new RectF(startX + fix, startY + fix, startX + edgeLength, startY + edgeLength);
mCenterX = content.centerX();
mCenterY = content.centerY();
// 得到路径
mSeekPath.reset();
mSeekPath.addArc(content, mOpenAngle / 2, CIRCLE_ANGLE - mOpenAngle);
mSeekPathMeasure.setPath(mSeekPath, false);
computeThumbPos(mProgressPresent);
resetShaderColor();
// 绘制progress路径
mProgressPath.reset();
float total = CIRCLE_ANGLE - mOpenAngle;//100%进度的扇形角度
float percent = ((float) getProgress() / (mMaxValue - mMinValue));
mProgressPath.addArc(content, mOpenAngle / 2, total * percent);
mProgressPathMeasure.setPath(mProgressPath, false);//是否闭合开口，设置成false
resetProgressColor();
mInvertMatrix.reset();
mInvertMatrix.preRotate(-mRotateAngle, mCenterX, mCenterY);
mArcPaint.getFillPath(mSeekPath, mBorderPath);
mBorderPath.close();
mArcRegion.setPath(mBorderPath, new Region(0, 0, w, h));
}
// 重置 shader 颜色
private void resetShaderColor() {
// 计算渐变数组
float startPos = (mOpenAngle / 2) / CIRCLE_ANGLE;
float stopPos = (CIRCLE_ANGLE - (mOpenAngle / 2)) / CIRCLE_ANGLE;
int len = mArcColors.length - 1;
float distance = (stopPos - startPos) / len;
float pos[] = new float[mArcColors.length];
for (int i = 0; i < mArcColors.length; i++) {
pos[i] = startPos + (distance * i);
}
SweepGradient gradient = new SweepGradient(mCenterX, mCenterY, mArcColors, pos);
mArcPaint.setShader(gradient);
}
private void resetProgressColor() {
// 计算渐变数组
float startPos = (mOpenAngle / 2) / CIRCLE_ANGLE;
float stopPos = (CIRCLE_ANGLE - (mOpenAngle / 2)) / CIRCLE_ANGLE;
int len = mProgressColors.length - 1;
float distance = (stopPos - startPos) / len;
float pos[] = new float[mProgressColors.length];
for (int i = 0; i < mProgressColors.length; i++) {
pos[i] = startPos + (distance * i);
}
SweepGradient gradient = new SweepGradient(mCenterX, mCenterY, mProgressColors, pos);
mProgressPaint.setShader(gradient);
invalidate();
}
// 具体绘制
@Override
protected void onDraw(Canvas canvas) {
canvas.save();
canvas.rotate(mRotateAngle, mCenterX + mOffsetX, mCenterY + mOffsetY);
mShadowPaint.setShadowLayer(mShadowRadius * 2, 0, 0, getColor());
canvas.drawPath(mBorderPath, mShadowPaint);
canvas.drawPath(mSeekPath, mArcPaint);
mProgressPath.reset();
float total = CIRCLE_ANGLE - mOpenAngle;//100%进度的扇形角度
float percent = ((float) getProgress() / (mMaxValue - mMinValue));
mProgressPath.addArc(content, mOpenAngle / 2, total * percent);
mProgressPathMeasure.setPath(mProgressPath, false);//是否闭合开口，设置成false
resetProgressColor();
canvas.drawPath(mProgressPath, mProgressPaint);
if (mBorderWidth > 0) {
canvas.drawPath(mBorderPath, mBorderPaint);
}
if (mThumbShadowRadius > 0) {
mThumbPaint.setShadowLayer(mThumbShadowRadius, 0, 0, mThumbShadowColor);
canvas.drawCircle(mThumbX, mThumbY, mThumbRadius, mThumbPaint);
mThumbPaint.clearShadowLayer();
}
canvas.drawCircle(mThumbX, mThumbY, mThumbRadius, mThumbPaint);
canvas.restore();
}
private boolean moved = false;
private int lastProgress = -1;
@SuppressLint("ClickableViewAccessibility")
@Override
public boolean onTouchEvent(MotionEvent event) {
super.onTouchEvent(event);
int action = event.getActionMasked();
switch (action) {
case ACTION_DOWN:
moved = false;
judgeCanDrag(event);
if (null != mOnProgressChangeListener) {
mOnProgressChangeListener.onStartTrackingTouch(this);
}
break;
case ACTION_MOVE:
if (!mCanDrag) {
break;
}
float tempProgressPresent = getCurrentProgress(event.getX(), event.getY());
if (!mAllowTouchSkip) {
// 不允许突变
if (Math.abs(tempProgressPresent - mProgressPresent) > 0.5f) {
break;
}
}
// 允许突变 或者非突变
mProgressPresent = tempProgressPresent;
computeThumbPos(mProgressPresent);
// 事件回调
if (null != mOnProgressChangeListener && getProgress() != lastProgress) {
mOnProgressChangeListener.onProgressChanged(this, getProgress(), true);
lastProgress = getProgress();
}
moved = true;
resetProgressColor();
break;
case ACTION_UP:
case ACTION_CANCEL:
if (null != mOnProgressChangeListener && moved) {
mOnProgressChangeListener.onStopTrackingTouch(this);
}
break;
}
mDetector.onTouchEvent(event);
invalidate();
return true;
}
// 判断是否允许拖动
private void judgeCanDrag(MotionEvent event) {
float[] pos = {event.getX(), event.getY()};
mInvertMatrix.mapPoints(pos);
if (getDistance(pos[0], pos[1]) <= mThumbRadius * 1.5) {
mCanDrag = true;
} else {
mCanDrag = false;
}
}
private class OnClickListener extends GestureDetector.SimpleOnGestureListener {
@Override
public boolean onSingleTapUp(MotionEvent e) {
// 判断是否点击在了进度区域
if (!isInArcProgress(e.getX(), e.getY())) return false;
// 点击允许突变
mProgressPresent = getCurrentProgress(e.getX(), e.getY());
computeThumbPos(mProgressPresent);
// 事件回调
if (null != mOnProgressChangeListener) {
mOnProgressChangeListener.onProgressChanged(ArcSeekBar.this, getProgress(), true);
mOnProgressChangeListener.onStopTrackingTouch(ArcSeekBar.this);
}
return true;
}
}
// 判断该点是否在进度条上面
private boolean isInArcProgress(float px, float py) {
float[] pos = {px, py};
mInvertMatrix.mapPoints(pos);
return mArcRegion.contains((int) pos[0], (int) pos[1]);
}
// 获取当前进度理论进度数值
private float getCurrentProgress(float px, float py) {
float diffAngle = getDiffAngle(px, py);
float progress = diffAngle / (CIRCLE_ANGLE - mOpenAngle);
if (progress < 0) progress = 0;
if (progress > 1) progress = 1;
return progress;
}
// 获得当前点击位置所成角度与开始角度之间的数值差
private float getDiffAngle(float px, float py) {
float angle = getAngle(px, py);
float diffAngle;
diffAngle = angle - mRotateAngle;
if (diffAngle < 0) {
diffAngle = (diffAngle + CIRCLE_ANGLE) % CIRCLE_ANGLE;
}
diffAngle = diffAngle - mOpenAngle / 2;
return diffAngle;
}
// 计算指定位置与内容区域中心点的夹角
private float getAngle(float px, float py) {
float angle = (float) ((Math.atan2(py - mCenterY, px - mCenterX)) * 180 / 3.14f);
if (angle < 0) {
angle += 360;
}
return angle;
}
// 计算指定位置与上次位置的距离
private float getDistance(float px, float py) {
return (float) Math.sqrt((px - mThumbX) * (px - mThumbX) + (py - mThumbY) * (py - mThumbY));
}
private int dp2px(int dp) {
return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, getContext().getResources().getDisplayMetrics());
}
// 计算拖动块应该显示的位置
private void computeThumbPos(float present) {
if (present < 0) present = 0;
if (present > 1) present = 1;
if (null == mSeekPathMeasure) return;
float distance = mSeekPathMeasure.getLength() * present;
mSeekPathMeasure.getPosTan(distance, mTempPos, mTempTan);
mThumbX = mTempPos[0];
mThumbY = mTempPos[1];
}
//--- 线性取色 ---------------------------------------------------------------------------------
/**
* 获取当前进度的具体颜色
*
* @return 当前进度在渐变中的颜色
*/
public int getColor() {
return getColor(mProgressPresent);
}
/**
* 获取某个百分比位置的颜色
*
* @param radio 取值[0,1]
* @return 最终颜色
*/
private int getColor(float radio) {
float diatance = 1.0f / (mArcColors.length - 1);
int startColor;
int endColor;
if (radio >= 1) {
return mArcColors[mArcColors.length - 1];
}
for (int i = 0; i < mArcColors.length; i++) {
if (radio <= i * diatance) {
if (i == 0) {
return mArcColors[0];
}
startColor = mArcColors[i - 1];
endColor = mArcColors[i];
float areaRadio = getAreaRadio(radio, diatance * (i - 1), diatance * i);
return getColorFrom(startColor, endColor, areaRadio);
}
}
return -1;
}
/**
* 计算当前比例在子区间的比例
*
* @param radio 总比例
* @param startPosition 子区间开始位置
* @param endPosition 子区间结束位置
* @return 自区间比例[0, 1]
*/
private float getAreaRadio(float radio, float startPosition, float endPosition) {
return (radio - startPosition) / (endPosition - startPosition);
}
/**
* 取两个颜色间的渐变区间 中的某一点的颜色
*
* @param startColor 开始的颜色
* @param endColor 结束的颜色
* @param radio 比例 [0, 1]
* @return 选中点的颜色
*/
private int getColorFrom(int startColor, int endColor, float radio) {
int redStart = Color.red(startColor);
int blueStart = Color.blue(startColor);
int greenStart = Color.green(startColor);
int redEnd = Color.red(endColor);
int blueEnd = Color.blue(endColor);
int greenEnd = Color.green(endColor);
int red = (int) (redStart + ((redEnd - redStart) * radio + 0.5));
int greed = (int) (greenStart + ((greenEnd - greenStart) * radio + 0.5));
int blue = (int) (blueStart + ((blueEnd - blueStart) * radio + 0.5));
return Color.argb(255, red, greed, blue);
}
//region 对外接口 -------------------------------------------------------------------------------
/**
* 设置进度
*
* @param progress 进度值
*/
public void setProgress(int progress) {
System.out.println("setProgress = " + progress);
if (progress > mMaxValue) progress = mMaxValue;
if (progress < mMinValue) progress = mMinValue;
mProgressPresent = (progress - mMinValue) * 1.0f / (mMaxValue - mMinValue);
System.out.println("setProgress present = " + mProgressPresent);
if (null != mOnProgressChangeListener) {
mOnProgressChangeListener.onProgressChanged(this, progress, false);
}
computeThumbPos(mProgressPresent);
resetProgressColor();
postInvalidate();
}
public void setProgress() {
setProgress(getProgress());
}
/**
* 获取当前进度数值
*
* @return 当前进度数值
*/
public int getProgress() {
return (int) (mProgressPresent * (mMaxValue - mMinValue)) + mMinValue;
}
/**
* 设置颜色
*
* @param colors 颜色
*/
public void setArcColors(int[] colors) {
mArcColors = colors;
resetShaderColor();
resetProgressColor();
postInvalidate();
}
/**
* 设置最大数值
* @param max 最大数值
*/
public void setMaxValue(int max) {
mMaxValue = max;
}
/**
* 设置最小数值
* @param min 最小数值
*/
public void setMinValue(int min) {
mMinValue = min;
}
/**
* 设置颜色
*
* @param colorArrayRes 颜色资源 R.array.arc_color
*/
public void setArcColors(int colorArrayRes) {
setArcColors(getColorsByArrayResId(getContext(), colorArrayRes));
}
// endregion -----------------------------------------------------------------------------------
// region 状态回调 ------------------------------------------------------------------------------
private OnProgressChangeListener mOnProgressChangeListener;
public void setOnProgressChangeListener(OnProgressChangeListener onProgressChangeListener) {
mOnProgressChangeListener = onProgressChangeListener;
}
public interface OnProgressChangeListener {
/**
* 进度发生变化
*
* @param seekBar 拖动条
* @param progress 当前进度数值
* @param isUser 是否是用户操作, true 表示用户拖动, false 表示通过代码设置
*/
void onProgressChanged(ArcSeekBar seekBar, int progress, boolean isUser);
/**
* 用户开始拖动
*
* @param seekBar 拖动条
*/
void onStartTrackingTouch(ArcSeekBar seekBar);
/**
* 用户结束拖动
*
* @param seekBar 拖动条
*/
void onStopTrackingTouch(ArcSeekBar seekBar);
}
}attrs.xml
color颜色值：
- #343434
- #626262
- #fff
- #FFE881
- #fefefe
- #68D1F4
动图中 我的应用实例：
我修改的属性
| name | desc | format | default |
| arc_progress_background | 背景色 | reference |
arc_colors_default |
| arc_progress_front | 前景色 | reference |
arc_colors_default |
| arc_offset_x | 圆环X轴偏移量 | int | 0 |
| arc_offset_y | 圆环Y轴偏移量 | int | 0 |
前景色和后景色是从作者的arc_colors属性演变而来的
偏移量的目的：因为圆环宽度如果小于滑块宽度，会出现 滑块被裁剪的现象默认为0
功能简单，我就不放GitHub了。有心人可以去给原作者一个star
再次感谢作者：GcsSloop
作者的GitHub：GitHub - GcsSloop/arc-seekbar: Android 圆弧形 SeekBar。