溫馨提示×
您好，登錄后才能下訂單哦！
點擊 登錄注冊 即表示同意《億速云用戶服務條款》
您好，登錄后才能下訂單哦！
本文小編為大家詳細介紹“android怎么實現可以滑動的平滑曲線圖”，內容詳細，步驟清晰，細節處理妥當，希望這篇“android怎么實現可以滑動的平滑曲線圖”文章能幫助大家解決疑惑，下面跟著小編的思路慢慢深入，一起來學習新知識吧。
1 attr 屬性編寫
<!-- xy坐標軸顏色 --> <attr name="xy_line_color" format="color" /> <!-- xy坐標軸寬度 --> <attr name="xy_line_width" format="dimension" /> <!-- xy坐標軸文字顏色 --> <attr name="xy_text_color" format="color" /> <!-- xy坐標軸文字大小 --> <attr name="xy_text_size" format="dimension" /> <!-- 折線圖中折線的顏色 --> <attr name="line_color" format="color" /> <!-- x軸各個坐標點水平間距 --> <attr name="interval" format="dimension" /> <!-- 背景顏色 --> <attr name="bg_color" format="color" /> <!-- 曲線選中外部顏色 --> <attr name="select_circle_color" format="color" /> <!-- 曲線選中內部顏色 --> <attr name="select_reminder_color" format="color" /> <!--是否抬手滾動--> <attr name="isScroll" format="boolean" /> <declare-styleable name="ChartView"> <attr name="xy_line_color" /> <attr name="xy_line_width" /> <attr name="xy_text_color" /> <attr name="xy_text_size" /> <attr name="line_color" /> <attr name="interval" /> <attr name="bg_color" /> <attr name="select_circle_color" /> <attr name="select_reminder_color" /> <attr name="isScroll" /> <!--提示框跟滑動顯示的位置--> <attr name="show_position"> <enum name="first" value="1" /> <enum name="middle" value="2" /> <enum name="end" value="3" /> </attr> </declare-styleable>
2 ChartView
package com.laisontech.commonuilibrary.customviews;
import android.animation.Animator;
import android.animation.ValueAnimator;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.PorterDuff;
import android.graphics.PorterDuffXfermode;
import android.graphics.Rect;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.util.Log;
import android.util.TypedValue;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;
import android.view.animation.DecelerateInterpolator;
import com.laisontech.commonuilibrary.R;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
/**
* 自定義折線圖
*/
public class ChartView extends View {
private static final int FIRST = 1;
private static final int MIDDLE = 2;
private static final int END = 3;
//xy坐標軸顏色
private int xyLineColor = 0xffCFE2CF;
//折線選中的圓形顏色
private int selectCircleColor = 0xff00A8FF;
//選中數據提示框顏色
private int selectReminderColor = 0xff00A8FF;
//折線中圓形內部部顏色
private int xyTextColor = 0xff0014FF;
//折線圖中折線的顏色
private int lineColor = 0xffFD00FF;
//xy坐標軸寬度
private int xyLineWidth = dpToPx(1);
//xy坐標軸文字大小
private int xyTextSize = spToPx(12);
//x軸各個坐標點水平間距
private int interval = dpToPx(40);
//背景顏色
private int bgColor = 0xffffffff;
//是否有起手時的滑動感
private boolean isScroll = false;
//提示框顯示位置
private int mShowPositionType = 3;
//繪制XY軸坐標對應的畫筆
private Paint mXYPaint;
//繪制XY軸的文本對應的畫筆
private Paint mXYTextPaint;
//畫折線對應的畫筆
private Paint mSpinnerLinePaint;
private int width;
private int height;
//x軸的原點坐標
private int mXOri;
//y軸的原點坐標
private int mYOri;
//第一個點X的坐標
private float mXInit;
//第一個點對應的最大X坐標
private float maxXInit;
//第一個點對應的最小X坐標
private float minXInit;
//x軸坐標對應的數據
private List<String> mXData = new ArrayList<>();
//y軸坐標對應的數據
private List<Integer> mYData = new ArrayList<>();
//折線對應的數據
private Map<String, Integer> mSpinnerValue = new HashMap<>();
//點擊的點對應的X軸的第幾個點，默認1
private int selectIndex = 1;
//X軸刻度文本對應的最大矩形，為了選中時，在x軸文本畫的框框大小一致，獲取從數據中得到的x軸數據，獲得最長數據
private Rect xValueRect;
//速度檢測器
private VelocityTracker mTracker;
//是否為短距離滑動
private boolean isShortSlide = false;
//獲取尺寸的的中間
private int mSelectMiddle = 0;
//曲線切率
private float mLineSmoothness = 0.18f;
public ChartView(Context context) {
this(context, null);
}
public ChartView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public ChartView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init(context, attrs, defStyleAttr);
initPaint();
}
//設置切率
public void setLineSmoothness(float lineSmoothness) {
if (lineSmoothness != this.mLineSmoothness) {
this.mLineSmoothness = lineSmoothness;
}
}
/**
* 初始化
*/
private void initPaint() {
mXYPaint = new Paint();
mXYPaint.setAntiAlias(true);
mXYPaint.setStrokeWidth(xyLineWidth);
mXYPaint.setStrokeJoin(Paint.Join.ROUND);
mXYPaint.setColor(xyLineColor);
mXYTextPaint = new Paint();
mXYTextPaint.setAntiAlias(true);
mXYTextPaint.setTextSize(xyTextSize);
mXYTextPaint.setStrokeJoin(Paint.Join.ROUND);
mXYTextPaint.setColor(xyTextColor);
mXYTextPaint.setStyle(Paint.Style.STROKE);
mSpinnerLinePaint = new Paint();
mSpinnerLinePaint.setAntiAlias(true);
mSpinnerLinePaint.setStrokeWidth(xyLineWidth);
mSpinnerLinePaint.setColor(lineColor);
mSpinnerLinePaint.setStyle(Paint.Style.STROKE);
mSpinnerLinePaint.setStrokeJoin(Paint.Join.ROUND);
}
/**
* 初始化
*
* @param context
* @param attrs
* @param defStyleAttr
*/
private void init(Context context, AttributeSet attrs, int defStyleAttr) {
TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.ChartView, defStyleAttr, 0);
int count = array.getIndexCount();
for (int i = 0; i < count; i++) {
int attr = array.getIndex(i);
if (attr == R.styleable.ChartView_xy_line_color) {
xyLineColor = array.getColor(attr, xyLineColor);
} else if (attr == R.styleable.ChartView_xy_line_width) {
xyLineWidth = (int) array.getDimension(attr, TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, xyLineWidth, getResources().getDisplayMetrics()));
} else if (attr == R.styleable.ChartView_xy_text_color) {
xyTextColor = array.getColor(attr, xyTextColor);
} else if (attr == R.styleable.ChartView_xy_text_size) {
xyTextSize = (int) array.getDimension(attr, TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, xyTextSize, getResources().getDisplayMetrics()));
} else if (attr == R.styleable.ChartView_line_color) {
lineColor = array.getColor(attr, lineColor);
} else if (attr == R.styleable.ChartView_interval) {
interval = (int) array.getDimension(attr, TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_PX, interval, getResources().getDisplayMetrics()));
} else if (attr == R.styleable.ChartView_bg_color) {
bgColor = array.getColor(attr, bgColor);
} else if (attr == R.styleable.ChartView_select_circle_color) {
selectCircleColor = array.getColor(attr, selectCircleColor);
} else if (attr == R.styleable.ChartView_select_reminder_color) {
selectReminderColor = array.getColor(attr, selectReminderColor);
} else if (attr == R.styleable.ChartView_isScroll) {
isScroll = array.getBoolean(attr, isScroll);
} else if (attr == R.styleable.ChartView_show_position) {
mShowPositionType = array.getInt(attr, mShowPositionType);
}
}
array.recycle();
}
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
if (changed) {
width = getWidth();
height = getHeight();
//Y軸文本的最大寬度
float textYWdith = getTextBounds(mYData.get(getListItemMaxIndex(mYData)) + "", mXYTextPaint).width();
for (int i = 0; i < mYData.size(); i++) {//求取y軸文本最大的寬度
float temp = getTextBounds(mYData.get(i) + "", mXYTextPaint).width();
if (temp > textYWdith)
textYWdith = temp;
}
int dp2 = dpToPx(2);
int dp3 = dpToPx(3);
mXOri = (int) (dp2 + textYWdith + dp2 + xyLineWidth);
//獲取x軸的最長文本的寬度所占的矩形
xValueRect = getTextBounds(mXData.get(getListItemMaxIndex(mXData)), mXYTextPaint);
//X軸文本高度
float textXHeight = xValueRect.height();
for (int i = 0; i < mXData.size(); i++) {
Rect rect = getTextBounds(mXData.get(i) + "", mXYTextPaint);
if (rect.height() > textXHeight)
textXHeight = rect.height();
if (rect.width() > xValueRect.width())
xValueRect = rect;
}
mYOri = (int) (height - dp2 - textXHeight - dp3 - xyLineWidth);
mXInit = mXOri + xValueRect.width() / 2 + dpToPx(5);
minXInit = width - (width - mXOri) * 0.1f - interval * (mXData.size() - 1);
maxXInit = mXInit;
}
selectIndex = getSelectIndexFromShowType(mShowPositionType);
super.onLayout(changed, left, top, right, bottom);
}
@Override
protected void onDraw(Canvas canvas) {
canvas.drawColor(bgColor);
drawXY(canvas);
drawBrokenLineAndPoint(canvas);
}
/**
* 繪制交點處對應的點
*/
private void drawBrokenLineAndPoint(Canvas canvas) {
if (mXData.size() <= 0)
return;
int layerId = canvas.saveLayer(0, 0, width, height, null, Canvas.ALL_SAVE_FLAG);
drawBrokenLine(canvas);
drawBrokenPoint(canvas);
// 將超出x軸坐標的部分截掉
mSpinnerLinePaint.setStyle(Paint.Style.FILL);
mSpinnerLinePaint.setColor(bgColor);
mSpinnerLinePaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
RectF rectF = new RectF(0, 0, mXOri, height);
canvas.drawRect(rectF, mSpinnerLinePaint);
mSpinnerLinePaint.setXfermode(null);
canvas.restoreToCount(layerId);
}
/**
* 繪制曲線對應的點
*/
private void drawBrokenPoint(Canvas canvas) {
float dp2 = dpToPx(2);
float dp4 = dpToPx(4);
float dp7 = dpToPx(7);
Log.e("selectIndex", "index:" + selectIndex);
//繪制節點
for (int i = 0; i < mXData.size(); i++) {
float x = mXInit + interval * i;
float y = mYOri - mYOri * (1 - 0.1f) * mSpinnerValue.get(mXData.get(i)) / mYData.get(mYData.size() - 1);
//繪制選中點
if (i == selectIndex - 1) {
mSpinnerLinePaint.setStyle(Paint.Style.FILL);
//設置選中顏色
mSpinnerLinePaint.setColor(selectCircleColor);
canvas.drawCircle(x, y, dp7, mSpinnerLinePaint);
mSpinnerLinePaint.setColor(selectReminderColor);
canvas.drawCircle(x, y, dp4, mSpinnerLinePaint);
drawFloatTextBox(canvas, x, y - dp7, mSpinnerValue.get(mXData.get(i)));
}
//繪制普通節點
mSpinnerLinePaint.setStyle(Paint.Style.FILL);
mSpinnerLinePaint.setColor(Color.WHITE);
canvas.drawCircle(x, y, dp2, mSpinnerLinePaint);
mSpinnerLinePaint.setStyle(Paint.Style.STROKE);
mSpinnerLinePaint.setColor(lineColor);
canvas.drawCircle(x, y, dp2, mSpinnerLinePaint);
}
}
/**
* 繪制浮動框
* */
private void drawFloatTextBox(Canvas canvas, float x, float y, int text) {
int dp6 = dpToPx(6);
int dp18 = dpToPx(18);
//p1
Path path = new Path();
path.moveTo(x, y);
//p2
path.lineTo(x - dp6, y - dp6);
//p3
path.lineTo(x - dp18, y - dp6);
//p4
path.lineTo(x - dp18, y - dp6 - dp18);
//p5
path.lineTo(x + dp18, y - dp6 - dp18);
//p6
path.lineTo(x + dp18, y - dp6);
//p7
path.lineTo(x + dp6, y - dp6);
//p1
path.lineTo(x, y);
canvas.drawPath(path, mSpinnerLinePaint);
mSpinnerLinePaint.setColor(Color.WHITE);
mSpinnerLinePaint.setTextSize(spToPx(14));
Rect rect = getTextBounds(text + "", mSpinnerLinePaint);
canvas.drawText(text + "", x - rect.width() / 2, y - dp6 - (dp18 - rect.height()) / 2, mSpinnerLinePaint);
}
/**
* 繪制平滑曲線
*/
private void drawBrokenLine(Canvas canvas) {
mSpinnerLinePaint.setStyle(Paint.Style.STROKE);
mSpinnerLinePaint.setColor(lineColor);
//繪制折線
Path path = new Path();
float prePreviousPointX = Float.NaN;
float prePreviousPointY = Float.NaN;
float previousPointX = Float.NaN;
float previousPointY = Float.NaN;
float currentPointX = Float.NaN;
float currentPointY = Float.NaN;
float nextPointX;
float nextPointY;
int lineSize = mXData.size();
for (int i = 0; i < lineSize; i++) {
float x;
float y;
if (Float.isNaN(currentPointX)) {
currentPointX = getSpinnerPoint(i).x;
currentPointY = getSpinnerPoint(i).y;
}
if (Float.isNaN(previousPointX)) {
//是第一個點?
if (i > 0) {
previousPointX = getSpinnerPoint(i - 1).x;
previousPointY = getSpinnerPoint(i - 1).y;
} else {
//用當前點表示上一個點
previousPointX = currentPointX;
previousPointY = currentPointY;
}
}
if (Float.isNaN(prePreviousPointX)) {
//是前兩個點?
if (i > 1) {
prePreviousPointX = getSpinnerPoint(i - 2).x;
prePreviousPointY = getSpinnerPoint(i - 2).y;
} else {
//當前點表示上上個點
prePreviousPointX = previousPointX;
prePreviousPointY = previousPointY;
}
}
// 判斷是不是最后一個點了
if (i < lineSize - 1) {
nextPointX = getSpinnerPoint(i + 1).x;
nextPointY = getSpinnerPoint(i + 1).y;
} else {
//用當前點表示下一個點
nextPointX = currentPointX;
nextPointY = currentPointY;
}
if (i == 0) {
// 將Path移動到開始點
path.moveTo(currentPointX, currentPointY);
} else {
// 求出控制點坐標
final float firstDiffX = (currentPointX - prePreviousPointX);
final float firstDiffY = (currentPointY - prePreviousPointY);
final float secondDiffX = (nextPointX - previousPointX);
final float secondDiffY = (nextPointY - previousPointY);
final float firstControlPointX = previousPointX + (mLineSmoothness * firstDiffX);
final float firstControlPointY = previousPointY + (mLineSmoothness * firstDiffY);
final float secondControlPointX = currentPointX - (mLineSmoothness * secondDiffX);
final float secondControlPointY = currentPointY - (mLineSmoothness * secondDiffY);
//畫出曲線
path.cubicTo(firstControlPointX, firstControlPointY, secondControlPointX, secondControlPointY,
currentPointX, currentPointY);
}
// 更新
prePreviousPointX = previousPointX;
prePreviousPointY = previousPointY;
previousPointX = currentPointX;
previousPointY = currentPointY;
currentPointX = nextPointX;
currentPointY = nextPointY;
}
canvas.drawPath(path, mSpinnerLinePaint);
}
/**
* 繪制XY坐標
*/
private void drawXY(Canvas canvas) {
int length = dpToPx(5);//刻度的長度
//繪制Y坐標
canvas.drawLine(mXOri - xyLineWidth / 2, 0, mXOri - xyLineWidth / 2, mYOri, mXYPaint);
//繪制箭頭
mXYPaint.setStyle(Paint.Style.STROKE);
Path path = new Path();
path.moveTo(mXOri - xyLineWidth / 2 - dpToPx(5), dpToPx(12));
path.lineTo(mXOri - xyLineWidth / 2, xyLineWidth / 2);
path.lineTo(mXOri - xyLineWidth / 2 + dpToPx(5), dpToPx(12));
canvas.drawPath(path, mXYPaint);
//繪制刻度
int yLength = (int) (mYOri * (1 - 0.1f) / (mYData.size() - 1));//y軸上面空出10%,計算出y軸刻度間距
for (int i = 0; i < mYData.size(); i++) {
//繪制刻度
canvas.drawLine(mXOri, mYOri - yLength * i + xyLineWidth / 2, mXOri + length, mYOri - yLength * i + xyLineWidth / 2, mXYPaint);
mXYTextPaint.setColor(xyTextColor);
//繪制文本
String text = mYData.get(i) + "";
Rect rect = getTextBounds(text, mXYTextPaint);
canvas.drawText(text, 0, text.length(), mXOri - xyLineWidth - dpToPx(2) - rect.width(), mYOri - yLength * i + rect.height() / 2, mXYTextPaint);
}
//繪制坐標
canvas.drawLine(mXOri, mYOri + xyLineWidth / 2, width, mYOri + xyLineWidth / 2, mXYPaint);
//繪制箭頭
mXYPaint.setStyle(Paint.Style.STROKE);
path = new Path();
//整個長度
float xLength = mXInit + interval * (mXData.size() - 1) + (width - mXOri) * 0.1f;
if (xLength < width)
xLength = width;
path.moveTo(xLength - dpToPx(12), mYOri + xyLineWidth / 2 - dpToPx(5));
path.lineTo(xLength - xyLineWidth / 2, mYOri + xyLineWidth / 2);
path.lineTo(xLength - dpToPx(12), mYOri + xyLineWidth / 2 + dpToPx(5));
canvas.drawPath(path, mXYPaint);
//繪制x軸刻度
for (int i = 0; i < mXData.size(); i++) {
float x = mXInit + interval * i;
if (x >= mXOri) {//只繪制從原點開始的區域
mXYTextPaint.setColor(xyTextColor);
canvas.drawLine(x, mYOri, x, mYOri - length, mXYPaint);
//繪制X軸文本
String text = mXData.get(i);
Rect rect = getTextBounds(text, mXYTextPaint);
if (i == selectIndex - 1) {
mXYTextPaint.setColor(lineColor);
canvas.drawText(text, 0, text.length(), x - rect.width() / 2, mYOri + xyLineWidth + dpToPx(2) + rect.height(), mXYTextPaint);
canvas.drawRoundRect(x - xValueRect.width() / 2 - dpToPx(3), mYOri + xyLineWidth + dpToPx(1), x + xValueRect.width() / 2 + dpToPx(3), mYOri + xyLineWidth + dpToPx(2) + xValueRect.height() + dpToPx(2), dpToPx(2), dpToPx(2), mXYTextPaint);
} else {
canvas.drawText(text, 0, text.length(), x - rect.width() / 2, mYOri + xyLineWidth + dpToPx(2) + rect.height(), mXYTextPaint);
}
}
}
}
private float startX;
private float startx;
@Override
public boolean onTouchEvent(MotionEvent event) {
if (isScrolling)
return super.onTouchEvent(event);
//當該view獲得點擊事件，就請求父控件不攔截事件
this.getParent().requestDisallowInterceptTouchEvent(true);
obtainVelocityTracker(event);
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
startX = event.getX();
startx = event.getX();
Log.e("XXXX", "down:" + startX + "");
break;
case MotionEvent.ACTION_MOVE:
//滑動距離小于等于8的時候任務為短距離滑動
//當前x軸的尺寸與設置的x軸間隔的距離之乘積大于 屏幕中的顯示布局寬度與x軸七點之差時，開始移動
if (interval * mXData.size() > width - mXOri) {
//獲取滑動的距離
float dis = event.getX() - startX;
//重新賦值給startX
startX = event.getX();
//當前x原點距離與左右滑動的距離之和沒有最小值大，則將當前x距離賦值為最小，以下相似
if (mXInit + dis < minXInit) {
mXInit = minXInit;
} else if (mXInit + dis > maxXInit) {
mXInit = maxXInit;
} else {
mXInit = mXInit + dis;
}
invalidate();
}
break;
case MotionEvent.ACTION_UP:
isShortSlide = Math.abs(event.getX() - startx) <= dpToPx(8);
clickAction(event);
scrollAfterActionUp();
this.getParent().requestDisallowInterceptTouchEvent(false);
recycleVelocityTracker();
break;
case MotionEvent.ACTION_CANCEL:
//增加這行代碼防止與父類的滑動事件沖突
this.getParent().requestDisallowInterceptTouchEvent(false);
recycleVelocityTracker();
break;
}
return true;
}
//是否正在滑動
private boolean isScrolling = false;
/**
* 手指抬起后的滑動處理
*/
private void scrollAfterActionUp() {
if (!isScroll)
return;
final float velocity = getVelocity();
float scrollLength = maxXInit - minXInit;
if (Math.abs(velocity) < 10000)
scrollLength = (maxXInit - minXInit) * Math.abs(velocity) / 10000;
ValueAnimator animator = ValueAnimator.ofFloat(0, scrollLength);
animator.setDuration((long) (scrollLength / (maxXInit - minXInit) * 1000));//時間最大為1000毫秒，此處使用比例進行換算
animator.setInterpolator(new DecelerateInterpolator());
animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() {
@Override
public void onAnimationUpdate(ValueAnimator valueAnimator) {
float value = (float) valueAnimator.getAnimatedValue();
if (velocity < 0 && mXInit > minXInit) {//向左滑動
if (mXInit - value <= minXInit)
mXInit = minXInit;
else
mXInit = mXInit - value;
} else if (velocity > 0 && mXInit < maxXInit) {//向右滑動
if (mXInit + value >= maxXInit)
mXInit = maxXInit;
else
mXInit = mXInit + value;
}
invalidate();
}
});
animator.addListener(new Animator.AnimatorListener() {
@Override
public void onAnimationStart(Animator animator) {
isScrolling = true;
}
@Override
public void onAnimationEnd(Animator animator) {
isScrolling = false;
}
@Override
public void onAnimationCancel(Animator animator) {
isScrolling = false;
}
@Override
public void onAnimationRepeat(Animator animator) {
}
});
animator.start();
}
/**
* 獲取速度
*
* @return
*/
private float getVelocity() {
if (mTracker != null) {
mTracker.computeCurrentVelocity(1000);
return mTracker.getXVelocity();
}
return 0;
}
/**
* 點擊X軸坐標或者折線節點
* */
// 44 142 139
private void clickAction(MotionEvent event) {
int dp8 = dpToPx(8);
float eventX = event.getX();
float eventY = event.getY();
if (!isShortSlide) {
for (int i = 0; i < mXData.size(); i++) {
float x = mXInit + interval * i;
float start = mXOri;
if (x >= start + (mSelectMiddle - 1) * interval && x < start + mSelectMiddle * interval) {
selectIndex = i + 1;
invalidate();
}
}
return;
}
for (int i = 0; i < mXData.size(); i++) {
//節點
float x = mXInit + interval * i;
float y = mYOri - mYOri * (1 - 0.1f) * mSpinnerValue.get(mXData.get(i)) / mYData.get(mYData.size() - 1);
if (eventX >= x - dp8 && eventX <= x + dp8 &&
eventY >= y - dp8 && eventY <= y + dp8 && selectIndex != i + 1) {//每個節點周圍范圍內都是可點擊區域
selectIndex = i + 1;
invalidate();
return;
}
//X軸刻度
String text = mXData.get(i);
Rect rect = getTextBounds(text, mXYTextPaint);
x = mXInit + interval * i;
y = mYOri + xyLineWidth + dpToPx(2);
if (eventX >= x - rect.width() / 2 - dp8 && eventX <= x + rect.width() + dp8 / 2 &&
eventY >= y - dp8 && eventY <= y + rect.height() + dp8 && selectIndex != i + 1) {
selectIndex = i + 1;
invalidate();
return;
}
}
}
/**
* 獲取速度跟蹤器
*
* @param event
*/
private void obtainVelocityTracker(MotionEvent event) {
if (!isScroll)
return;
if (mTracker == null) {
mTracker = VelocityTracker.obtain();
}
mTracker.addMovement(event);
}
/**
* 回收速度跟蹤器
*/
private void recycleVelocityTracker() {
if (mTracker != null) {
mTracker.recycle();
mTracker = null;
}
}
/**
* 根據用戶輸入顯示類型，在滑動時在不同的位置顯示提示框
*/
private int getSelectIndexFromShowType(int showPositionType) {
int visibleScale = (width - mXOri) / interval;
switch (showPositionType) {
case FIRST:
mSelectMiddle = 1;
return mSelectMiddle;
case MIDDLE:
if (mXData.size() <= visibleScale) {
mSelectMiddle = middleIndex(mXData.size());
} else {
mSelectMiddle = middleIndex(visibleScale);
}
return mSelectMiddle; //屏幕可顯示的刻度
case END:
if (mXData.size() <= visibleScale) {
mSelectMiddle = mXData.size();
} else {
mSelectMiddle = visibleScale;
}
return visibleScale;
default:
mSelectMiddle = 0;
return mSelectMiddle;
}
}
public void setValue(Map<String, Integer> value) {
this.mSpinnerValue = value;
invalidate();
}
public void setValue(Map<String, Integer> value, List<String> xValue, List<Integer> yValue) {
this.mSpinnerValue = value;
this.mXData = xValue;
this.mYData = yValue;
invalidate();
}
public Map<String, Integer> getValue() {
return mSpinnerValue;
}
/**
* 獲取丈量文本的矩形
*
* @param text
* @param paint
* @return
*/
private Rect getTextBounds(String text, Paint paint) {
Rect rect = new Rect();
paint.getTextBounds(text, 0, text.length(), rect);
return rect;
}
/**
* dp轉化成為px
*
* @param dp
* @return
*/
private int dpToPx(int dp) {
float density = getContext().getResources().getDisplayMetrics().density;
return (int) (dp * density + 0.5f * (dp >= 0 ? 1 : -1));
}
/**
* sp轉化為px
*
* @param sp
* @return
*/
private int spToPx(int sp) {
float scaledDensity = getContext().getResources().getDisplayMetrics().scaledDensity;
return (int) (scaledDensity * sp + 0.5f * (sp >= 0 ? 1 : -1));
}
/**
* 獲取集合中最長的index
*/
private static final int NULL_INDEX = -1;
public int getListItemMaxIndex(List<?> data) {
if (data == null || data.size() < 1) {
return NULL_INDEX;
}
int max = (data.get(0) + "").length();
for (int i = 0; i < data.size(); i++) {
String s = data.get(i) + "";
if (s.length() > max) {
return i;
}
}
return NULL_INDEX;
}
//獲得在滑動結束的時候在屏幕內的點
private int middleIndex(int size) {
if (size % 2 == 0) {
return size / 2;
} else {
return size / 2 + 1;
}
}
/**
* 根據兩點坐標獲取中間某個點
*
* @param from 坐標1
* @param to 坐標2
*/
//獲取已知點的斜率 y = kx+b
private float getSlope(Point from, Point to) {
float k = (to.y - from.y) / (to.x - from.x);
Log.e("Point", "參數b：" + k);
return k;
}
//獲取參數 b
private float getParams(Point from, Point to) {
float b = from.y - (getSlope(from, to) * from.x);
Log.e("Point", "參數b：" + b);
return b;
}
//根據兩點間的坐標獲取x軸的任意一個坐標x值,
private float getArbitrarilyX(Point from, Point to, int grade, int needGrade) {
//獲得輸入的新坐標
float x = ((to.x - from.x) * needGrade) / grade + from.x;
Log.e("Point", "x坐標值：" + x);
return x;
}
//獲取坐標值
private Point getPoint(Point from, Point to, int grade, int needGrade) {
Point point = new Point();
point.setX(getArbitrarilyX(from, to, grade, needGrade));
float slope = getSlope(from, to);
point.setY(slope * point.x + getParams(from, to));
return point;
}
//獲取繪制折線的點
private Point getSpinnerPoint(int valueIndex) {
float x = mXInit + interval * (valueIndex);
float y = mYOri - mYOri * (1 - 0.1f) * mSpinnerValue.get(mXData.get(valueIndex)) / mYData.get(mYData.size() - 1);
return new Point(x, y);
}
private class Point {
float x;
float y;
public Point() {
}
public float getX() {
return x;
}
public void setX(float x) {
this.x = x;
}
public float getY() {
return y;
}
public void setY(float y) {
this.y = y;
}
public Point(float x, float y) {
this.x = x;
this.y = y;
}
@Override
public String toString() {
return "Point{" +
"x=" + x +
", y=" + y +
'}';
}
}
}讀到這里，這篇“android怎么實現可以滑動的平滑曲線圖”文章已經介紹完畢，想要掌握這篇文章的知識點還需要大家自己動手實踐使用過才能領會，如果想了解更多相關內容的文章，歡迎關注億速云行業資訊頻道。
免責聲明：本站發布的內容（圖片、視頻和文字）以原創、轉載和分享為主，文章觀點不代表本網站立場，如果涉及侵權請聯系站長郵箱：is@yisu.com進行舉報，并提供相關證據，一經查實，將立刻刪除涉嫌侵權內容。
