Android画轴效果 Android仿京东首页画轴效果
冷不冷 人气:0记得之前京东首页有一个效果,有一个画轴,然后可以滚动画轴,去打开画(不知道怎么去形容这个效果,就叫做画轴效果吧- -!),然后去做相关操作,刚开始看到这个效果,想法是动态的去改变一个ImageView的高度,基本效果也就出来了,不过滚动部分的内容,当时接触的也不是很多,只是看过一些大牛的博客,略微了解了一点,当时也忙着写项目,也就没去多想,前些天忽然想到这个效果,就想着实现一下,不过京东新版本好像去掉这个东西了,只能凭着自己的记忆来大概搞一下,也是对滑动这部分内容的一个小练习吧.
先看一下效果图:
一、需求分析
看到效果之后,先来分析一下:
首先是需要一个可以滑动的画轴,并且这个画轴需要一定的滑动空间,有滑动的效果,这个用Scroller帮助完成就可以了.
然后看一下画轴点击移动时候的背景图,是跟随画轴移动,动态改变高度的.这个用一个ImageView来搞定,设置ImageView的scaleType就可以了,不过这个地方有一些小问题,下面会说.
二、具体实现
简单分析完,来实现一下,先来做一下画轴.创建一个ScrollPaintView继承自RelativeLayout,因为需要一定的滑动空间,所以需要是一个ViewGroup.
ScrollPaintView的一些基本属性:
public class ScrollPaintView extends RelativeLayout { /** * TAG */ private static final String TAG = "ScrollPaintView"; /** * 默认滚轴高度 */ private final int DEFAULT_PAINT_SCROLL_HEIGHT = 25; /** * 默认滚动的速度 */ private final int DEFAULT_SCROLL_SPEED = 1000; /** * 默认分割点高度 */ private final int DEFAULT_PARTITION_NODE = 150; /** * 默认画轴文字大小 */ private final int DEFAULT_PAINT_SCROLL_TXT_SIZE = 16; /** * Scroller */ private Scroller mScroller; /** * 滚轴Iv */ private ImageView mPaintScrollImageView; /** * 滚轴Tv */ private TextView mPaintScrollTextView; /** * 图画Iv */ private ImageView mPaintView; /** * 画轴图 */ private Bitmap mPaintScrollBp; /** * 画轴高度 */ private int mPaintIvHeight; /** * 画轴文字 */ private String mPaintScrollTxt; /** * 画轴文字大小 */ private float mPaintScrollTxtSize; /** * 画轴文字颜色 */ private int mPaintScrollTxtColor; /** * 图画开始时的高度 */ private int mPaintStartHeight; /** * 上一次获取的Y */ private int mLastY; /** * 滚动速度 */ private int mScrollSpeed; /** * 分隔节点 */ private int partitionNode; /** * 是否是向上滚动 */ private boolean isScrllerTop = false; /** * 是否正在点击 */ private boolean isClick = false; /** * 布局参数 */ private LayoutParams lpp; /** * 屏幕高度 */ private int screenHeight; /** * 屏幕宽度 */ private int screenWidth; /** * 回调监听 */ private ScrollPaintCompleteListener listener; /** * 上一次滚动的Y值 */ private int lastScrollY; /** * 构造方法 */ public ScrollPaintView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); // 获取属性 TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.ScrollPaintView); mPaintIvHeight = (int) ta.getDimension(R.styleable.ScrollPaintView_paintScrollHeight, TypedValue.applyDimension( TypedValue.COMPLEX_UNIT_DIP, DEFAULT_PAINT_SCROLL_HEIGHT, getResources().getDisplayMetrics())); mScrollSpeed = ta.getInteger(R.styleable.ScrollPaintView_scrollSpeed, DEFAULT_SCROLL_SPEED); partitionNode = ta.getInteger(R.styleable.ScrollPaintView_scrollPartitionNode, DEFAULT_PARTITION_NODE); mPaintScrollBp = drawableToBitamp(ta.getDrawable(R.styleable.ScrollPaintView_paintScrollSrc)); mPaintScrollTxt = ta.getString(R.styleable.ScrollPaintView_paintScrollTxt); mPaintScrollTxtColor = ta.getColor(R.styleable.ScrollPaintView_paintScrollTxtColor, Color.BLACK); mPaintScrollTxtSize = px2sp(ta.getDimensionPixelSize(R.styleable.ScrollPaintView_paintScrollTxtSize, DEFAULT_PAINT_SCROLL_TXT_SIZE)); ta.recycle(); } }
看一下创建画轴:
/** * 创建滚轴 */ private void makePaintScroll() { // 如果已经存在,则不再创建 if (null != mPaintScrollImageView || null != mPaintScrollTextView) { return; } // 创建滚轴 mPaintScrollImageView = new ImageView(getContext()); LayoutParams lp = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); lp.height = mPaintIvHeight; mPaintScrollImageView.setLayoutParams(lp); mPaintScrollImageView.setScaleType(ImageView.ScaleType.FIT_XY); mPaintScrollImageView.setImageBitmap(null == mPaintScrollBp ? makeDefaultScroll() : mPaintScrollBp); addView(mPaintScrollImageView); // 创建文字 mPaintScrollTextView = new TextView(getContext()); LayoutParams lpt = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); lpt.height = mPaintIvHeight; mPaintScrollTextView.setLayoutParams(lpt); mPaintScrollTextView.setText(null == mPaintScrollTxt ? "" : mPaintScrollTxt); mPaintScrollTextView.setTextSize(mPaintScrollTxtSize); mPaintScrollTextView.setTextColor(mPaintScrollTxtColor); mPaintScrollTextView.setGravity(Gravity.CENTER); addView(mPaintScrollTextView); } /** * 设置默认的滚轴 * * @return */ private Bitmap makeDefaultScroll() { Bitmap defaultBp = Bitmap.createBitmap(screenWidth, mPaintIvHeight, Bitmap.Config.ARGB_8888); //填充颜色 defaultBp.eraseColor(Color.parseColor("#FF0000")); return defaultBp; }
创建了一个画轴ImageView和一个文字TextView作为初始的画轴,如果没有传入画轴的图片,则默认去创建一个画轴.不难理解,接着去配合Scroller,让画轴滚动起来.
简单滚动:
/** * 处理View */ private void handleView() { // 初始化Scroller mScroller = new Scroller(getContext()); // 画轴点击效果 mPaintScrollImageView.setOnTouchListener(new OnTouchListener() { @Override public boolean onTouch(View view, MotionEvent event) { int x = (int) event.getRawX(); int y = (int) event.getRawY(); int action = event.getAction(); switch (action) { case MotionEvent.ACTION_DOWN: isClick = true; mLastY = y; if (!mScroller.isFinished()) { // 如果上次的调用没有执行完就取消。 mScroller.abortAnimation(); } return true; case MotionEvent.ACTION_MOVE: // 移动的距离 int dy = y - mLastY; mLastY = y; // 滑动 scrollBy(0, -dy); return true; case MotionEvent.ACTION_UP: mScroller.startScroll(getScrollX(), getScrollY(), -getScrollX(), -getScrollY(), 1000); invalidate(); return true; } return false; } }); } /** * 滑动处理 */ @Override public void computeScroll() { if (mScroller.computeScrollOffset()) { // 计算新位置,并判断上一个滚动是否完成。 scrollTo(mScroller.getCurrX(), mScroller.getCurrY()); invalidate(); } }
这样滑动处理就做完了,在布局中引用一下,看一下效果
activity_main:
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:background="#eeeeee" tools:context="com.example.junweiliu.scrollpaintdemo.MainActivity"> <!--画轴控件--> <com.example.junweiliu.scrollpaintdemo.widget.ScrollPaintView android:id="@+id/spv_paint" android:layout_width="match_parent" android:layout_height="match_parent" app:paintScrollHeight="25dp" app:paintScrollSrc="@mipmap/paint_scroll_img" app:paintScrollTxt="拉我看看" app:paintScrollTxtColor="#FF000000" app:paintScrollTxtSize="16sp" > </com.example.junweiliu.scrollpaintdemo.widget.ScrollPaintView> </RelativeLayout>
效果图:
滚动条基本能用了,接着来设置一个ImageView来配合使用下,先获取到一个ImageView,然后拖动画轴时,来动态改变ImageView的高度,在做这部分内容前,先来考虑下,因为需求需要的是图画整体不会变形,是一点一点拉开的感觉,就像是打开一幅画一样,那么用哪种scaleType能满足呢.试了好多种,来分别看一下:
相关代码:
提供一个设置ImageView的方法
在MotionEvent.ACTION_MOVE:中动态改变ImageView的高度
滑动时动态改变ImageView的高度
/** * 设置paintView * * @param paintView */ public void setPaintView(ImageView paintView) { if (null == paintView) { Log.e(TAG, "设置的View为空"); return; } mPaintView = paintView; }
MotionEvent.ACTION_MOVE:
// 滑动处理 case MotionEvent.ACTION_MOVE: ... // 动态改变高度 if (Math.abs(getScrollY()) > 0) { lpp.height = mPaintStartHeight + Math.abs(getScrollY()); mPaintView.setLayoutParams(lpp); }
滑动处理:
/** * 滑动处理 */ @Override public void computeScroll() { if (mScroller.computeScrollOffset()) { // 计算新位置,并判断上一个滚动是否完成。 // 请求处理点击事件,防止父控件滑动 requestDisallowInterceptTouchEvent(true); scrollTo(mScroller.getCurrX(), mScroller.getCurrY()); // 重新设置显示的控件高度 if (0 < Math.abs(mScroller.getCurrY())) { if (!isScrllerTop) { lpp.height = mPaintStartHeight + Math.abs(mScroller.getCurrY()) + mPaintIvHeight / 2; } else { lpp.height = mPaintStartHeight + Math.abs(mScroller.getCurrY()) - mPaintIvHeight / 2; } } else { lpp.height = mPaintStartHeight; } mPaintView.setLayoutParams(lpp); invalidate(); } }
设置不同scaleType效果,简单试几个效果:
fitXY:
centerCrop:
matrix:
观察一下,好像那个效果都不是很好,不过matrix拉开的效果和预期需要的是一样的,不过用matrix之后,就没有办法设置其他scaleType了,没办法把图片进行缩放了,这肿么办呢,其实很简单,只需要把显示的图片提前进行一下缩放就可以了.
处理图片相关:
/** * 设置paintView * * @param paintView */ public void setPaintView(ImageView paintView) { if (null == paintView) { Log.e(TAG, "设置的View为空"); return; } // 处理图片,对图片按照屏幕宽高比进行缩放 Bitmap bp = drawableToBitamp(paintView.getDrawable()); paintView.setImageBitmap(scaleBitmal(bp)); // 设置缩放形式 paintView.setScaleType(ImageView.ScaleType.MATRIX); mPaintView = paintView; } /** * drawable转bitmap * * @param drawable * @return */ private Bitmap drawableToBitamp(Drawable drawable) { if (null == drawable) { return null; } if (drawable instanceof BitmapDrawable) { BitmapDrawable bd = (BitmapDrawable) drawable; return bd.getBitmap(); } int w = drawable.getIntrinsicWidth(); int h = drawable.getIntrinsicHeight(); Bitmap bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(bitmap); drawable.setBounds(0, 0, w, h); drawable.draw(canvas); return bitmap; } /** * 按照屏幕宽高缩放图片 * * @param bp * @return */ private Bitmap scaleBitmal(Bitmap bp) { // 宽度比例 float scaleW = (float) screenWidth / (float) bp.getWidth(); // 高度比例 float scaleH = (float) screenHeight / (float) bp.getHeight(); // 矩阵,用于缩放图片 Matrix matrix = new Matrix(); matrix.postScale(scaleW, scaleH); // 缩放后的图片 Bitmap scaleBp = Bitmap.createBitmap(bp, 0, 0, bp.getWidth(), bp.getHeight(), matrix, true); return scaleBp; }
看一下效果:
效果还不错,接下来就是做一下细节上的处理,设置一个临界点,让画轴向上或者向下滚动,设置边界点,让画轴不越界等等.还有一般都是在ScrollView中使用到这个效果,所以要去处理一下事件冲突,当然还有去重写一下onMeasure方法,不然会出现不显示的情况.(相信大家也遇到过ScrollView里边嵌套ListView导致ListView显示不全)这里就不再详细介绍了.直接贴下代码.
三、完整代码
MainActivity:
package com.example.junweiliu.scrollpaintdemo; import android.content.Intent; import android.os.Bundle; import android.os.Handler; import android.os.Message; import android.support.v7.app.AppCompatActivity; import android.view.View; import android.widget.ImageView; import android.widget.TextView; import android.widget.Toast; import com.example.junweiliu.scrollpaintdemo.widget.ScrollPaintView; public class MainActivity extends AppCompatActivity { private static final String TAG = "MainActivity"; /** * 需要显示的IV */ private ImageView mPaintIv; /** * 画轴 */ private ScrollPaintView mScrollPaintView; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initView(); } /** * 初始化控件 */ private void initView() { mPaintIv = (ImageView) findViewById(R.id.iv_paint); mScrollPaintView = (ScrollPaintView) findViewById(R.id.spv_paint); mScrollPaintView.setPaintView(mPaintIv); mPaintIv.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Toast.makeText(MainActivity.this, "功夫!", Toast.LENGTH_SHORT).show(); } }); mScrollPaintView.setScrollPaintCompleteListener(new ScrollPaintView.ScrollPaintCompleteListener() { @Override public void onScrollTouch(TextView tv) { mPaintIv.setVisibility(View.VISIBLE); } @Override public void onScrollTop(TextView tv) { // Log.e(TAG, "收缩了"); tv.setText("拉我看看"); if (View.VISIBLE == mPaintIv.getVisibility()) { mPaintIv.setVisibility(View.GONE); } } @Override public void onScrollBottom(TextView tv) { // Log.e(TAG, "展开了"); tv.setText("到底了"); Intent intent = new Intent(MainActivity.this, DetailActivity.class); startActivity(intent); // 延迟800毫秒重置位置 new Handler(new Handler.Callback() { @Override public boolean handleMessage(Message message) { mScrollPaintView.replaceScroll(); return false; } }).sendEmptyMessageDelayed(0, 600); } @Override public void onScrollMove(TextView tv) { // Log.e(TAG, "移动了"); tv.setText("请上下拖动"); } }); } }
ScrollPaintView:
package com.example.junweiliu.scrollpaintdemo.widget; import android.app.Activity; import android.content.Context; import android.content.res.TypedArray; import android.graphics.Bitmap; import android.graphics.Canvas; import android.graphics.Color; import android.graphics.Matrix; import android.graphics.Rect; import android.graphics.drawable.BitmapDrawable; import android.graphics.drawable.Drawable; import android.util.AttributeSet; import android.util.DisplayMetrics; import android.util.Log; import android.util.TypedValue; import android.view.Gravity; import android.view.MotionEvent; import android.view.View; import android.widget.ImageView; import android.widget.RelativeLayout; import android.widget.Scroller; import android.widget.TextView; import com.example.junweiliu.scrollpaintdemo.R; /** * Created by junweiliu on 16/12/10. */ public class ScrollPaintView extends RelativeLayout { /** * TAG */ private static final String TAG = "ScrollPaintView"; /** * 默认滚轴高度 */ private final int DEFAULT_PAINT_SCROLL_HEIGHT = 25; /** * 默认滚动的速度 */ private final int DEFAULT_SCROLL_SPEED = 1000; /** * 默认分割点高度 */ private final int DEFAULT_PARTITION_NODE = 150; /** * 默认画轴文字大小 */ private final int DEFAULT_PAINT_SCROLL_TXT_SIZE = 16; /** * Scroller */ private Scroller mScroller; /** * 滚轴Iv */ private ImageView mPaintScrollImageView; /** * 滚轴Tv */ private TextView mPaintScrollTextView; /** * 图画Iv */ private ImageView mPaintView; /** * 画轴图 */ private Bitmap mPaintScrollBp; /** * 画轴高度 */ private int mPaintIvHeight; /** * 画轴文字 */ private String mPaintScrollTxt; /** * 画轴文字大小 */ private float mPaintScrollTxtSize; /** * 画轴文字颜色 */ private int mPaintScrollTxtColor; /** * 图画开始时的高度 */ private int mPaintStartHeight; /** * 上一次获取的Y */ private int mLastY; /** * 滚动速度 */ private int mScrollSpeed; /** * 分隔节点 */ private int partitionNode; /** * 是否是向上滚动 */ private boolean isScrllerTop = false; /** * 是否正在点击 */ private boolean isClick = false; /** * 布局参数 */ private LayoutParams lpp; /** * 屏幕高度 */ private int screenHeight; /** * 屏幕宽度 */ private int screenWidth; /** * 回调监听 */ private ScrollPaintCompleteListener listener; /** * 上一次滚动的Y值 */ private int lastScrollY; /** * 回调接口 */ public interface ScrollPaintCompleteListener { /** * 点击时的回调 */ public void onScrollTouch(TextView tv); /** * 收缩时的回调 */ public void onScrollTop(TextView tv); /** * 展开时的回调 */ public void onScrollBottom(TextView tv); /** * 滚动中的回调 */ public void onScrollMove(TextView tv); } public ScrollPaintView(Context context) { this(context, null); } public ScrollPaintView(Context context, AttributeSet attrs) { this(context, attrs, 0); } public ScrollPaintView(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); // 获取属性 TypedArray ta = context.obtainStyledAttributes(attrs, R.styleable.ScrollPaintView); mPaintIvHeight = (int) ta.getDimension(R.styleable.ScrollPaintView_paintScrollHeight, TypedValue.applyDimension( TypedValue.COMPLEX_UNIT_DIP, DEFAULT_PAINT_SCROLL_HEIGHT, getResources().getDisplayMetrics())); mScrollSpeed = ta.getInteger(R.styleable.ScrollPaintView_scrollSpeed, DEFAULT_SCROLL_SPEED); partitionNode = ta.getInteger(R.styleable.ScrollPaintView_scrollPartitionNode, DEFAULT_PARTITION_NODE); mPaintScrollBp = drawableToBitamp(ta.getDrawable(R.styleable.ScrollPaintView_paintScrollSrc)); mPaintScrollTxt = ta.getString(R.styleable.ScrollPaintView_paintScrollTxt); mPaintScrollTxtColor = ta.getColor(R.styleable.ScrollPaintView_paintScrollTxtColor, Color.BLACK); mPaintScrollTxtSize = px2sp(ta.getDimensionPixelSize(R.styleable.ScrollPaintView_paintScrollTxtSize, DEFAULT_PAINT_SCROLL_TXT_SIZE)); ta.recycle(); init(); makePaintScroll(); handleView(); } /** * 设置paintView * * @param paintView */ public void setPaintView(ImageView paintView) { if (null == paintView) { Log.e(TAG, "设置的View为空"); return; } // 处理图片,对图片按照屏幕宽高比进行缩放 Bitmap bp = drawableToBitamp(paintView.getDrawable()); paintView.setImageBitmap(scaleBitmal(bp)); // 设置缩放形式 paintView.setScaleType(ImageView.ScaleType.MATRIX); mPaintView = paintView; } /** * 设置回调 */ public void setScrollPaintCompleteListener(ScrollPaintCompleteListener listener) { if (null != listener) { this.listener = listener; } } /** * 初始化 */ private void init() { mScroller = new Scroller(getContext()); lpp = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); // 获取屏幕信息 DisplayMetrics displayMetrics = new DisplayMetrics(); ((Activity) getContext()).getWindowManager().getDefaultDisplay() .getMetrics(displayMetrics); // 屏幕高度 screenHeight = displayMetrics.heightPixels; // 屏幕宽度 screenWidth = displayMetrics.widthPixels; } /** * 创建滚轴 */ private void makePaintScroll() { // 如果已经存在,则不再创建 if (null != mPaintScrollImageView || null != mPaintScrollTextView) { return; } // 创建滚轴 mPaintScrollImageView = new ImageView(getContext()); LayoutParams lp = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); lp.height = mPaintIvHeight; mPaintScrollImageView.setLayoutParams(lp); mPaintScrollImageView.setScaleType(ImageView.ScaleType.FIT_XY); mPaintScrollImageView.setImageBitmap(null == mPaintScrollBp ? makeDefaultScroll() : mPaintScrollBp); addView(mPaintScrollImageView); // 创建文字 mPaintScrollTextView = new TextView(getContext()); LayoutParams lpt = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT); lpt.height = mPaintIvHeight; mPaintScrollTextView.setLayoutParams(lpt); mPaintScrollTextView.setText(null == mPaintScrollTxt ? "" : mPaintScrollTxt); mPaintScrollTextView.setTextSize(mPaintScrollTxtSize); mPaintScrollTextView.setTextColor(mPaintScrollTxtColor); mPaintScrollTextView.setGravity(Gravity.CENTER); addView(mPaintScrollTextView); } /** * 测量方法 * * @param widthMeasureSpec * @param heightMeasureSpec */ @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { super.onMeasure(widthMeasureSpec, heightMeasureSpec); if (null != mPaintView && getTop() + mPaintIvHeight != mPaintView.getHeight()) { // 重新设置图画高度 mPaintStartHeight = getTop() + mPaintIvHeight / 2; lpp.height = mPaintStartHeight; mPaintView.setLayoutParams(lpp); } // 测量状态栏高度 Rect frame = new Rect(); ((Activity) getContext()).getWindow().getDecorView().getWindowVisibleDisplayFrame(frame); int statusBarHeight = frame.top; // 高度为屏幕高度减去状态栏高度和top的高度 setMeasuredDimension(screenWidth, screenHeight - getTop() - statusBarHeight); } /** * 处理View */ private void handleView() { mPaintScrollImageView.setOnTouchListener(new OnTouchListener() { @Override public boolean onTouch(View view, MotionEvent event) { if (null == mPaintView) { Log.e(TAG, "设置的View为空"); return true; } // 获取点击的XY坐标 int x = (int) event.getRawX(); int y = (int) event.getRawY(); int action = event.getAction(); switch (action) { case MotionEvent.ACTION_DOWN: { // 请求处理点击事件 requestDisallowInterceptTouchEvent(true); isClick = true; mLastY = y; if (!mScroller.isFinished()) { // 如果上次的调用没有执行完就取消。 mScroller.abortAnimation(); } if (null != listener) { listener.onScrollTouch(mPaintScrollTextView); } return true; } case MotionEvent.ACTION_MOVE: { // 移动的距离 int dy = y - mLastY; mLastY = y; // 滑动 scrollBy(0, -dy); // 如果是向上滑动并且是在初始位置,则不去做处理 if (getScrollY() >= 0 && dy <= 0) { lpp.height = mPaintStartHeight; mPaintView.setLayoutParams(lpp); scrollTo(0, 0); return true; } // 如果是向下滑动并且超过屏幕高度,则不去处理 if (Math.abs(getScrollY()) >= getHeight() - mPaintIvHeight && dy >= 0) { lpp.height = mPaintStartHeight + getHeight() - mPaintIvHeight; mPaintView.setLayoutParams(lpp); scrollTo(0, -(getHeight() - mPaintIvHeight)); return true; } // 滚动回调 if (null != listener) { listener.onScrollMove(mPaintScrollTextView); } // 重新设置显示的控件高度 if (Math.abs(getScrollY()) > 0) { lpp.height = mPaintStartHeight + Math.abs(getScrollY()); mPaintView.setLayoutParams(lpp); } return true; } case MotionEvent.ACTION_UP: // 恢复事件处理 requestDisallowInterceptTouchEvent(false); isClick = false; // 没有发生移动 if (getScrollY() >= 0) { if (null != listener) { listener.onScrollTop(mPaintScrollTextView); } return true; } if (-getScrollY() < partitionNode) { // 如果小于临界值,则返回起始坐标 // XY都从滑动的距离回去,最后一个参数是多少毫秒内执行完这个动作。 isScrllerTop = true; mScroller.startScroll(getScrollX(), getScrollY(), -getScrollX(), -getScrollY(), mScrollSpeed); } else { // 如果大于临界值,则展开 isScrllerTop = false; mScroller.startScroll(getScrollX(), getScrollY(), -getScrollX(), -(getHeight() - (-getScrollY()) - mPaintIvHeight), mScrollSpeed); } invalidate(); return true; } return false; } }); } /** * 滑动处理 */ @Override public void computeScroll() { if (mScroller.computeScrollOffset()) { // 计算新位置,并判断上一个滚动是否完成。 // 请求处理点击事件,防止父控件滑动 requestDisallowInterceptTouchEvent(true); scrollTo(mScroller.getCurrX(), mScroller.getCurrY()); // 重新设置显示的控件高度 if (0 < Math.abs(mScroller.getCurrY())) { if (!isScrllerTop) { lpp.height = mPaintStartHeight + Math.abs(mScroller.getCurrY()) + mPaintIvHeight / 2; } else { lpp.height = mPaintStartHeight + Math.abs(mScroller.getCurrY()) - mPaintIvHeight / 2; } } else { lpp.height = mPaintStartHeight; } mPaintView.setLayoutParams(lpp); invalidate(); } else { // 重新设置画图高度,防止高度异常 if (mPaintView.getHeight() > mPaintStartHeight + Math.abs(mScroller.getCurrY()) && !isScrllerTop && mScroller.getStartY() > 0) { lpp.height = mPaintStartHeight + Math.abs(mScroller.getCurrY()); mPaintView.setLayoutParams(lpp); } } // 防止多次调用 if (lastScrollY != mScroller.getCurrY()) { // 收缩完成 if (mScroller.getCurrY() >= 0 && !isClick) { if (null != listener) { listener.onScrollTop(mPaintScrollTextView); } } // 展开完成 if (-mScroller.getCurrY() >= getHeight() - mPaintIvHeight && !isClick) { if (null != listener) { listener.onScrollBottom(mPaintScrollTextView); } } lastScrollY = mScroller.getCurrY(); } } /** * 重置滚动 */ public void replaceScroll() { // 重置信息 scrollTo(0, 0); mScroller.setFinalY(0); lastScrollY = 0; lpp.height = mPaintStartHeight; mPaintView.setLayoutParams(lpp); if (null != listener) { listener.onScrollTop(mPaintScrollTextView); } } /** * drawable转bitmap * * @param drawable * @return */ private Bitmap drawableToBitamp(Drawable drawable) { if (null == drawable) { return null; } if (drawable instanceof BitmapDrawable) { BitmapDrawable bd = (BitmapDrawable) drawable; return bd.getBitmap(); } int w = drawable.getIntrinsicWidth(); int h = drawable.getIntrinsicHeight(); Bitmap bitmap = Bitmap.createBitmap(w, h, Bitmap.Config.ARGB_8888); Canvas canvas = new Canvas(bitmap); drawable.setBounds(0, 0, w, h); drawable.draw(canvas); return bitmap; } /** * 按照屏幕宽高缩放图片 * * @param bp * @return */ private Bitmap scaleBitmal(Bitmap bp) { // 宽度比例 float scaleW = (float) screenWidth / (float) bp.getWidth(); // 高度比例 float scaleH = (float) screenHeight / (float) bp.getHeight(); // 矩阵,用于缩放图片 Matrix matrix = new Matrix(); matrix.postScale(scaleW, scaleH); // 缩放后的图片 Bitmap scaleBp = Bitmap.createBitmap(bp, 0, 0, bp.getWidth(), bp.getHeight(), matrix, true); return scaleBp; } /** * 设置默认的滚轴 * * @return */ private Bitmap makeDefaultScroll() { Bitmap defaultBp = Bitmap.createBitmap(screenWidth, mPaintIvHeight, Bitmap.Config.ARGB_8888); //填充颜色 defaultBp.eraseColor(Color.parseColor("#FF0000")); return defaultBp; } /** * 将px值转换为sp值,保证文字大小不变 */ public int px2sp(float pxValue) { final float fontScale = getContext().getResources().getDisplayMetrics().scaledDensity; return (int) (pxValue / fontScale + 0.5f); } }
activity_main:
<?xml version="1.0" encoding="utf-8"?> <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent" android:background="#eeeeee" tools:context="com.example.junweiliu.scrollpaintdemo.MainActivity"> <ScrollView android:layout_width="match_parent" android:layout_height="match_parent"> <RelativeLayout android:layout_width="match_parent" android:layout_height="match_parent"> <!--头部图片部分--> <ImageView android:id="@+id/iv_banner" android:layout_width="match_parent" android:layout_height="200dp" android:scaleType="fitXY" android:src="@mipmap/show_banner"/> <!--中间内容部分--> <LinearLayout android:id="@+id/ll_first" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/iv_banner" android:layout_marginTop="20dp" android:orientation="horizontal" android:padding="16dp"> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginRight="16dp" android:layout_weight="1" android:gravity="center_horizontal" android:orientation="vertical"> <ImageView android:layout_width="80dp" android:layout_height="120dp" android:scaleType="fitXY" android:src="@mipmap/movie_playbill_a"/> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:gravity="center" android:text="艺术片" android:textColor="#666666"/> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginRight="16dp" android:layout_weight="1" android:gravity="center_horizontal" android:orientation="vertical"> <ImageView android:layout_width="80dp" android:layout_height="120dp" android:scaleType="fitXY" android:src="@mipmap/movie_playbill_b"/> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:gravity="center" android:text="怀旧片" android:textColor="#666666"/> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginRight="16dp" android:layout_weight="1" android:gravity="center_horizontal" android:orientation="vertical"> <ImageView android:layout_width="80dp" android:layout_height="120dp" android:scaleType="fitXY" android:src="@mipmap/movie_playbill_c"/> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:gravity="center" android:text="科幻片" android:textColor="#666666"/> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="center_horizontal" android:orientation="vertical"> <ImageView android:layout_width="80dp" android:layout_height="120dp" android:scaleType="fitXY" android:src="@mipmap/movie_playbill_d"/> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:gravity="center" android:text="动画片" android:textColor="#666666"/> </LinearLayout> </LinearLayout> <LinearLayout android:id="@+id/ll_sencond" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/ll_first" android:layout_marginTop="20dp" android:orientation="horizontal" android:padding="16dp"> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginRight="16dp" android:layout_weight="1" android:gravity="center_horizontal" android:orientation="vertical"> <ImageView android:layout_width="80dp" android:layout_height="120dp" android:scaleType="fitXY" android:src="@mipmap/movie_playbill_a"/> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:gravity="center" android:text="艺术片" android:textColor="#666666"/> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginRight="16dp" android:layout_weight="1" android:gravity="center_horizontal" android:orientation="vertical"> <ImageView android:layout_width="80dp" android:layout_height="120dp" android:scaleType="fitXY" android:src="@mipmap/movie_playbill_b"/> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:gravity="center" android:text="怀旧片" android:textColor="#666666"/> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginRight="16dp" android:layout_weight="1" android:gravity="center_horizontal" android:orientation="vertical"> <ImageView android:layout_width="80dp" android:layout_height="120dp" android:scaleType="fitXY" android:src="@mipmap/movie_playbill_c"/> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:gravity="center" android:text="科幻片" android:textColor="#666666"/> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="center_horizontal" android:orientation="vertical"> <ImageView android:layout_width="80dp" android:layout_height="120dp" android:scaleType="fitXY" android:src="@mipmap/movie_playbill_d"/> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:gravity="center" android:text="动画片" android:textColor="#666666"/> </LinearLayout> </LinearLayout> <LinearLayout android:id="@+id/ll_threeth" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/ll_sencond" android:layout_marginTop="20dp" android:orientation="horizontal" android:padding="16dp"> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginRight="16dp" android:layout_weight="1" android:gravity="center_horizontal" android:orientation="vertical"> <ImageView android:layout_width="80dp" android:layout_height="120dp" android:scaleType="fitXY" android:src="@mipmap/movie_playbill_a"/> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:gravity="center" android:text="艺术片" android:textColor="#666666"/> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginRight="16dp" android:layout_weight="1" android:gravity="center_horizontal" android:orientation="vertical"> <ImageView android:layout_width="80dp" android:layout_height="120dp" android:scaleType="fitXY" android:src="@mipmap/movie_playbill_b"/> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:gravity="center" android:text="怀旧片" android:textColor="#666666"/> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginRight="16dp" android:layout_weight="1" android:gravity="center_horizontal" android:orientation="vertical"> <ImageView android:layout_width="80dp" android:layout_height="120dp" android:scaleType="fitXY" android:src="@mipmap/movie_playbill_c"/> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:gravity="center" android:text="科幻片" android:textColor="#666666"/> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="center_horizontal" android:orientation="vertical"> <ImageView android:layout_width="80dp" android:layout_height="120dp" android:scaleType="fitXY" android:src="@mipmap/movie_playbill_d"/> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:gravity="center" android:text="动画片" android:textColor="#666666"/> </LinearLayout> </LinearLayout> <LinearLayout android:id="@+id/ll_fourth" android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_below="@+id/ll_threeth" android:layout_marginTop="20dp" android:orientation="horizontal" android:padding="16dp"> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginRight="16dp" android:layout_weight="1" android:gravity="center_horizontal" android:orientation="vertical"> <ImageView android:layout_width="80dp" android:layout_height="120dp" android:scaleType="fitXY" android:src="@mipmap/movie_playbill_a"/> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:gravity="center" android:text="艺术片" android:textColor="#666666"/> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginRight="16dp" android:layout_weight="1" android:gravity="center_horizontal" android:orientation="vertical"> <ImageView android:layout_width="80dp" android:layout_height="120dp" android:scaleType="fitXY" android:src="@mipmap/movie_playbill_b"/> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:gravity="center" android:text="怀旧片" android:textColor="#666666"/> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_marginRight="16dp" android:layout_weight="1" android:gravity="center_horizontal" android:orientation="vertical"> <ImageView android:layout_width="80dp" android:layout_height="120dp" android:scaleType="fitXY" android:src="@mipmap/movie_playbill_c"/> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:gravity="center" android:text="科幻片" android:textColor="#666666"/> </LinearLayout> <LinearLayout android:layout_width="0dp" android:layout_height="match_parent" android:layout_weight="1" android:gravity="center_horizontal" android:orientation="vertical"> <ImageView android:layout_width="80dp" android:layout_height="120dp" android:scaleType="fitXY" android:src="@mipmap/movie_playbill_d"/> <TextView android:layout_width="match_parent" android:layout_height="wrap_content" android:layout_marginTop="10dp" android:gravity="center" android:text="动画片" android:textColor="#666666"/> </LinearLayout> </LinearLayout> <!--需要显示的图--> <ImageView android:id="@+id/iv_paint" android:layout_width="match_parent" android:layout_height="match_parent" android:scaleType="matrix" android:src="@mipmap/show_img" android:visibility="gone"/> <!--画轴控件--> <com.example.junweiliu.scrollpaintdemo.widget.ScrollPaintView android:id="@+id/spv_paint" android:layout_width="match_parent" android:layout_height="match_parent" android:layout_below="@+id/iv_banner" app:paintScrollHeight="25dp" app:paintScrollSrc="@mipmap/paint_scroll_img" app:paintScrollTxt="拉我看看" app:paintScrollTxtColor="#FF000000" app:paintScrollTxtSize="16sp" > </com.example.junweiliu.scrollpaintdemo.widget.ScrollPaintView> </RelativeLayout> </ScrollView> </RelativeLayout>
attr:
<?xml version="1.0" encoding="utf-8"?> <resources> <!--画轴的高度--> <attr name="paintScrollHeight" format="dimension"/> <!--画轴的图片--> <attr name="paintScrollSrc" format="reference"/> <!--画轴文字--> <attr name="paintScrollTxt" format="string"/> <!--画轴文字颜色--> <attr name="paintScrollTxtColor" format="color"/> <!--画轴文字大小--> <attr name="paintScrollTxtSize" format="dimension"/> <!--滚动速度--> <attr name="scrollSpeed" format="integer"/> <!--分割节点--> <attr name="scrollPartitionNode" format="integer"/> <declare-styleable name="ScrollPaintView"> <attr name="paintScrollHeight"/> <attr name="paintScrollSrc"/> <attr name="paintScrollTxt"/> <attr name="paintScrollTxtColor"/> <attr name="paintScrollTxtSize"/> <attr name="scrollSpeed"/> <attr name="scrollPartitionNode"/> </declare-styleable> </resources>
四、问题
滚动的时间不宜设置太短,因为动态设置ImageView高度时可能出现绘制速度赶不上滚动的速度,会出现错位,当然时间设置太短,也看不到这种滑动的效果了.暂时想到的做法就是这样,应该还会有更好的方法.
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