自定义View
自定义View分为三大类，第一种是自定义 View，第二种是自定义 ViewGroup，第三种是自定义组合控件。其中自定义View又分为继承系统控件（比如TextView）和继承View两种。自定义ViewGroup也分为继承ViewGroup 和继承系统特定的 ViewGroup（比如 RelativeLayout）
View的继承关系:
View 的部分继承关系，在这张图我们看到ViewGroup、TextView 等控件继承自 View，LinearLayout、RelativeLayout 等控件继承ViewGroup，TableLayout、RadioGroup等控件继承自LinearLayout，EditText、Button等控件继承自TextView，等等
TIM图片20181207151442.png
坐标系
Android坐标系
在Android中，将屏幕左上角的顶点作为Android坐标系的原点，这个原点向右是X轴正方向，向下是Y轴正方向，另外在触控事件中，使用getRawX（）和getRawY（）方法获得的坐标也是Android坐标系的坐标。
TIM图片20181207152002.png
View坐标系
除了Android坐标系，还有一个坐标系：View坐标系，它与Android坐标系并不冲突，两者是共同存在的，它们一起来帮助开发者更好地控制View。
TIM图片20181207152102.png
View的执行顺序
https://blog.csdn.net/oqihaogongyuan/article/details/50921560
init->onFinishInflate->onMeasure..->onSizeChanged->onLayout->onDraw()
OnTouchListener，onTouchEvent，onClickListener执行顺序:
首先执行OnTouchListener，之后为onTouchEvent，最后才执行onClickListener内的方法
其中onMeasure和onLayout会被多次调用.
1、init() 构造方法，这个不做解释，铁定第一个被调用。
作用：传入Context
2、onFinishInflate() 当View中所有的子控件均被映射成xml后触发
3、onMeasure() 在View放置到父容器时调用
作用：测量View的大小，也可以通过下面方式，修改View的大小
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
setMeasuredDimension(100,100);
}
也可以通过以下方式获取控件的宽和高
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
int width = MeasureSpec.getSize(widthMeasureSpec);
int height = MeasureSpec.getSize(heightMeasureSpec));
}
4、onSizeChanged() 在控件大小发生改变时调用。所以这里初始化会被调用一次
作用：获取控件的宽和高度
5,判断ListView的第一个item是否完全显示
ListView.getChildCount()
返回的是这个listView当前显示出来的item数量，也就是在屏幕上可以看到的数量。
ListView.getChildAt(int pos)
返回的是这个listView当前显示出来的item中的第pos项，也就是说索引是从显示出来的第一项开始计算的，如果屏幕上方有n个item看不见，那么这个函数的返回值就是n
ListView.getFirstVisiblePosition()
返回值是当前可以看到的第一个item，在所有item中（包括看不到的）的位置。
View.getTop()
返回值是这个View相对于它的父控件的top值，对于item而言，如果item只有一半显示出来（下半部分），那么返回值应该是 - 这个item的高度
8,getRawX(),getRawY(),getX(),getY(),getScrollX(),getScrollY()区别
1)、MotionEvent 中的getRawX(),getRawY(),getX(),getY()
getRawX()，getRawY()：触摸点相对于屏幕的位置 （像素）；
getX(),getY()：触摸点相对于父View的位置（像素）；
2)、View中的getScrollX(),getScrollY()
getScrollX()与getScrollY()的值由调用View的scrollTo(int x, int y)或者scrollBy(int x, int y)产生
其中scrollTo是将View中的内容移动到指定的坐标x、y处，此x、y是相对于View的左上角，而不是屏幕的左上角
scrollBy(int x, int y)则是改变View中的相对位置，参数x、y为距离上一次的相对位置。
x > 0,从右向左滑动，反之从左向右滑动；y > 0,从下向上滑动，反之从上向下滑动；
getScrollX(): 滑动后的位置相对于原始位置横向偏移量，向左滑动 getScrollX() > 0，反之小于0；
getScrollY():滑动后的位置相对于原始位置纵向偏移量，向上滑动getScrollY() > 0,反之小于0；
31521CF0-BBED-4913-9EA8-A6B504F62A01.png
7、onDraw() 最后就是绘制图形了
draw绘制基础
https://www.cnblogs.com/yongdaimi/p/8021965.html
https://blog.csdn.net/struggle323/article/details/50818320
自定义tab
TIM图片20181207160424.png
调用:
FragmentManager manager = getSupportFragmentManager();
CommFragmentPagerAdapter fragmentPagerAdapter = new CommFragmentPagerAdapter(manager, mList);
vpSigninList.setAdapter(fragmentPagerAdapter);
vpiSigninTab.setViewPager(vpSigninList);
vpiSigninTab.setDatas(mTabData);
vpSigninList.setCurrentItem(0);
xml文件
<com.fecmobile.sigemo.common.cusview.ViewPagerIndicator
android:id="@+id/id_stickynavlayout_indicator"
android:layout_width="match_parent"
android:layout_height="@dimen/height_32"
android:layout_marginLeft="@dimen/margin_10"
android:layout_marginRight="@dimen/margin_10"
android:layout_marginTop="@dimen/margin_10">
</com.fecmobile.sigemo.common.cusview.ViewPagerIndicator>
public class ViewPagerIndicator extends LinearLayout {
private ViewPager mViewPager;
private int width;
private int height;
private int visibleItemCount = 4;
private int itemCount = 4;
//绘制框框
private Paint paint;
private Paint paint2;
private float mWidth = 0;
private float mHeight = 0;
private float mLeft = 0;
private float mTop = 0;
private float radiusX = 19;
private float radiusY = 19;
private int mPadding = 0;
private List<String> mDatas;
private boolean isSetData = false;
private Context context;
private int currentPosition;
private boolean isAutoSelect = false;//判断是否进行切换
private float rebounceOffset;
private float mTranslationX;
private boolean isflag = true;
private TableClickListener tableClickListener;
private LableClickListener lableClickListener;//是否拦截点击indicator
public ViewPagerIndicator(Context context) {
super(context);
this.context = context;
init();
}
public ViewPagerIndicator(Context context,AttributeSet attrs) {
super(context,attrs);
this.context = context;
init();
}
public ViewPagerIndicator(Context context,AttributeSet attrs,int defStyleAttr) {
super(context,attrs,defStyleAttr);
this.context = context;
init();
}
private void init() {
radiusX = DensityUtils.dp2px(context,radiusX);
radiusY = DensityUtils.dp2px(context,radiusY);
L.d("画init" + radiusX + "," + radiusY);
this.setBackgroundDrawable(getResources().getDrawable(R.drawable.circle_tab));
paint = new Paint();
paint.setStyle(Paint.Style.FILL);
paint.setColor(getResources().getColor(R.color.color_9a));
paint.setAntiAlias(true);
paint2 = new Paint();
paint2.setStyle(Paint.Style.STROKE);
paint2.setStrokeWidth(2.0f);
paint2.setColor(getResources().getColor(R.color.color_ca));
paint2.setAntiAlias(true);
}
@Override
protected void onMeasure(int widthMeasureSpec,int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec,heightMeasureSpec);
L.d("画onMeasure" + isSetData + "," + widthMeasureSpec + "," + heightMeasureSpec);
width = getMeasuredWidth();
height = getMeasuredHeight();
mWidth = width / visibleItemCount;
mHeight = height;
}
private int currentWidthMeasureSpec;
private int currentHeightMeasureSpec;
@Override
protected void onSizeChanged(int w,int h,int oldw,int oldh) {
super.onSizeChanged(w,h,oldw,oldh);
L.d("画onSizeChanged" + isSetData + "," + w + "," + h + "," + oldw + "," + oldh);
if (isSetData) {
isSetData = false;
this.removeAllViews();
//添加TextView
for (int i = 0; i < mDatas.size(); i++) {
TextView tv = new TextView(context);
tv.setPadding(mPadding,mPadding,mPadding,mPadding);
// tv.setBackgroundResource(R.drawable.circle_background_tab);
tv.setText(mDatas.get(i));
LayoutParams lp = new LayoutParams(LayoutParams.MATCH_PARENT,LayoutParams.MATCH_PARENT);
lp.width = width / visibleItemCount;
lp.height = height;
tv.setGravity(Gravity.CENTER);
tv.setTextColor(getResources().getColor(R.color.pure_white));
tv.setTextSize(TypedValue.COMPLEX_UNIT_SP,14);
tv.setLayoutParams(lp);
final int finalI = i;
tv.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
boolean isIntercept = false;
if (lableClickListener != null) {
isIntercept = lableClickListener.onItemClick(finalI);
}
if (mViewPager != null && !isIntercept) {
mViewPager.setCurrentItem(finalI);
}
}
});
addView(tv);
}
setTitleColor();
}
measure(2,2);
}
@Override
protected void onFinishInflate() {
super.onFinishInflate();
}
@Override
protected void onLayout(boolean changed,int l,int t,int r,int b) {
super.onLayout(changed,l,t,r,b);
L.d("画onLayout");
}
@Override
protected void onDraw(Canvas canvas) {
L.d("画" + (mLeft + mPadding) + "," + (mTop + mPadding) + "," + (mLeft + mWidth - mPadding) + "," + (mTop + mHeight - mPadding) + "," + radiusX + "," + radiusY + "," +
paint);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
//drawRoundRect需要的最低API是21
canvas.drawRoundRect(mLeft + mPadding,mTop + mPadding,mLeft + mWidth - mPadding,mTop + mHeight - mPadding,radiusX,radiusY,paint);
} else {
canvas.drawRoundRect(new RectF(mLeft + mPadding,mTop + mPadding,mLeft + mWidth - mPadding,mTop + mHeight - mPadding),radiusX,radiusX,paint);
// canvas.drawRect(mLeft + mPadding, mTop + mPadding, mLeft + mWidth - mPadding, mTop + mHeight - mPadding, paint);
}
for (int i = 0; i < visibleItemCount - 1; i++) {
if (i != -1) {
//确定外切矩形范围
RectF rectF = new RectF(0,0,mHeight,mHeight);
//使rectf所确定的矩形向右偏移100像素，向下偏移20像素,170 ,64
rectF.offset((i * mWidth + (mWidth - mHeight)),0);
//绘制圆弧，不含圆心
canvas.drawArc(rectF,-90,180,false,paint2);
}
}
}
public void setTableClickListener(TableClickListener tableClickListener) {
this.tableClickListener = tableClickListener;
}
public void setLableClickListener(LableClickListener lableClickListener) {
this.lableClickListener = lableClickListener;
}
@Override
protected void dispatchDraw(Canvas canvas) {
//ogUtil.m();
// canvas.translate(mTranslationX, getHeight() - 2);
super.dispatchDraw(canvas);
}
public void setViewPager(ViewPager viewpager,int position) {
L.d("画setViewPager" + position);
this.mViewPager = viewpager;
this.currentPosition = position;
if (mViewPager != null) {
viewpager.setOnPageChangeListener(new ViewPager.OnPageChangeListener() {
@Override
public void onPageScrolled(int position,float positionOffset,int positionOffsetPixels) {
L.d("画圆" + isAutoSelect + "," + position + "," + positionOffset + "," + positionOffsetPixels);
//当移动的是最左边item
if (isAutoSelect && currentPosition == 0) {
//滑动手松开时，让最左边（即第一个）item滑动到左边缘位置
if (positionOffset > rebounceOffset / 2) {
mLeft = (position + (positionOffset - rebounceOffset / 2) * 2) * mWidth;
} else if (positionOffset > rebounceOffset / 3 && positionOffset < rebounceOffset / 2) {
//让最左边（即第一个）item 向右回弹一部分距离
mLeft = (position + (rebounceOffset / 2) - positionOffset) * mWidth * 6 / 12;
} else {
//让最左边（即最后一个）item 向左回弹到边缘位置
mLeft = (position + positionOffset) * mWidth * 6 / 12;
}
invalidate();
} else if (isAutoSelect && currentPosition == itemCount - 1) {
//当移动的是最右边（即最后一个）item
//滑动手松开时，让最右边（即最后一个）item滑动到右边缘位置
if (positionOffset >= rebounceOffset && positionOffset < (1 - (1 - rebounceOffset) / 2)) {
//
mLeft = (position + positionOffset / (1 - (1 - rebounceOffset) / 2)) * mWidth;
//当item数大于visibleItem可见数，本控件(本质LinearLayout)才滚动
if (visibleItemCount < itemCount) {
scrollTo((int)(mWidth * positionOffset / (1 - (1 - rebounceOffset) / 2) + (position - visibleItemCount + 1) * mWidth),0);
}
if ((mLeft + mWidth) > (getChildCount() * mWidth)) {
//当(mLeft + mWidth)大于最边缘的宽度时，设置
mLeft = (itemCount - 1) * mWidth;
}
} else if (positionOffset > (1 - (1 - rebounceOffset) / 2) && positionOffset < (1 - (1 - rebounceOffset) / 4)) {
//让最右边（即最后一个）item 向左回弹一部分距离
//当item数大于visibleItem可见数，且本控件未滚动到指定位置，则设置控件滚动到指定位置
if (visibleItemCount < itemCount && getScrollX() != (itemCount - visibleItemCount) * mWidth) {
scrollTo((int)((itemCount - visibleItemCount) * mWidth),0);
}
mLeft = (position + 1) * mWidth - (positionOffset - (1 - (1 - rebounceOffset) / 2)) * mWidth * 7 / 12;
} else {
//让最右边（即最后一个）item 向右回弹到边缘位置
//因为onPageScrolled 最后positionOffset会变成0，所以这里需要判断一下
//当positionOffset = 0 时，设置mLeft位置
if (positionOffset != 0) {
mLeft = (position + 1) * mWidth - (1.0f - positionOffset) * mWidth * 7 / 12;
if (mLeft > (itemCount - 1) * mWidth) {
mLeft = (itemCount - 1) * mWidth;
}
} else {
mLeft = (itemCount - 1) * mWidth;
}
}
//invalidate();
scroll(position,positionOffset);
} else {
//当移动的是中间item
scrollTo(position,positionOffset);
rebounceOffset = positionOffset;
}
setTitleColor();
}
@Override
public void onPageSelected(int position) {
currentPosition = position;
if (tableClickListener != null) {
tableClickListener.onItemClick(position);
}
}
@Override
public void onPageScrollStateChanged(int state) {
if (state == 2) {
//当state = 2时，表示手松开，viewpager开启自动滑动
isAutoSelect = true;
}
if (state == 0) {
//当state = 0时，表示viewpager滑动停止
isAutoSelect = false;
}
}
});
}
}
public void setViewPager(ViewPager viewpager) {
setViewPager(viewpager,0);
}
/**
* 正常滑动
*/
private void scrollTo(int position,float positionOffset) {
//item数量大于可见item，linearlayout才滑动
if (visibleItemCount < itemCount) {
if (positionOffset > 0 && position > (visibleItemCount - 2)) {
this.scrollTo((int)(mWidth * positionOffset + (position - visibleItemCount + 1) * mWidth),0);
}
}
mLeft = (position + positionOffset) * mWidth;
invalidate();
}
/**
* 设置字体颜色
*/
private void setTitleColor() {
if (getChildCount() > 0) {
for (int i = 0; i < getChildCount(); i++) {
if (i == currentPosition) {
((TextView)getChildAt(currentPosition)).setTextColor(getResources().getColor(R.color.pure_white));
} else {
((TextView)getChildAt(i)).setTextColor(getResources().getColor(R.color.color_9a));
}
}
}
}
/**
* 设置内容数据
*/
public void setDatas(List<String> mDatas) {
this.isSetData = true;
this.mDatas = mDatas;
this.itemCount = mDatas.size();
if (itemCount < visibleItemCount) {
visibleItemCount = itemCount;
}
}
public void scroll(int position,float offset) {
/**
* <pre>
* 0-1:position=0 ;1-0:postion=0;
* </pre>
*/
mTranslationX = getWidth() / itemCount * (position + offset);
invalidate();
}
}
