code perfect

app/src/main/java/com/mxdl/customview/test/ViewPagerTestActivity.java

@@ -3,15 +3,22 @@ package com.mxdl.customview.test;
 import android.graphics.Color;
 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
+import android.util.Log;
 import android.view.LayoutInflater;
+import android.view.MotionEvent;
+import android.view.View;
+import android.widget.LinearLayout;
 import android.widget.TextView;
 
 import com.mxdl.customview.R;
+import com.mxdl.customview.test.view.MyTextView;
 import com.mxdl.customview.test.view.MyViewPager;
+import com.mxdl.customview.test.view.MyViewPager1;
+import com.mxdl.customview.util.MotionEventUtil;
 
 public class ViewPagerTestActivity extends AppCompatActivity {
 
-    private MyViewPager mViewPager;
+    private MyViewPager1 mViewPager;
     int[] colors = {Color.GREEN,Color.RED,Color.BLUE};
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -19,10 +26,27 @@ public class ViewPagerTestActivity extends AppCompatActivity {
         setContentView(R.layout.activity_view_pager_test);
         mViewPager = findViewById(R.id.view_my_pager);
         for(int i =0; i < 3; i++){
-            TextView txtContent  = (TextView) LayoutInflater.from(this).inflate(R.layout.item_test_view_pager, mViewPager,false);
+            LinearLayout layout  = (LinearLayout) LayoutInflater.from(this).inflate(R.layout.item_test_view_pager, null);
+            int widthPixels = getResources().getDisplayMetrics().widthPixels;
+            int heightPixels = getResources().getDisplayMetrics().heightPixels;
+            Log.v("MYTAG1","widthPixels:"+widthPixels+";height:"+heightPixels);
+            layout.setLayoutParams(new LinearLayout.LayoutParams(widthPixels, heightPixels));
+            TextView txtContent = layout.findViewById(R.id.txt_content);
             txtContent.setText(String.valueOf(i));
             txtContent.setBackgroundColor(colors[i]);
-            mViewPager.addView(txtContent);
+            mViewPager.addView(layout);
         }
     }
+
+    @Override
+    public boolean dispatchTouchEvent(MotionEvent ev) {
+        Log.v("MYTAG","Activity dispatchTouchEvent start..."+ MotionEventUtil.getEventType(ev));
+        return super.dispatchTouchEvent(ev);
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent event) {
+        Log.v("MYTAG","Activity onTouchEvent start..."+ MotionEventUtil.getEventType(event));
+        return super.onTouchEvent(event);
+    }
 }

app/src/main/java/com/mxdl/customview/test/view/MyButton.java

+package com.mxdl.customview.test.view;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.util.Log;
+import android.view.MotionEvent;
+import android.widget.Button;
+
+import com.mxdl.customview.util.MotionEventUtil;
+
+/**
+ * Description: <MyButton><br>
+ * Author:      mxdl<br>
+ * Date:        2019/10/25<br>
+ * Version:     V1.0.0<br>
+ * Update:     <br>
+ */
+public class MyButton extends android.support.v7.widget.AppCompatButton {
+    public MyButton(Context context) {
+        super(context);
+    }
+
+    public MyButton(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public MyButton(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+    @Override
+    public boolean dispatchTouchEvent(MotionEvent event) {
+        Log.v("MYTAG","MyButton dispatchTouchEvent start..."+ MotionEventUtil.getEventType(event));
+        return super.dispatchTouchEvent(event);
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent event) {
+        Log.v("MYTAG","MyButton onTouchEvent start..."+ MotionEventUtil.getEventType(event));
+        return super.onTouchEvent(event);
+    }
+}

app/src/main/java/com/mxdl/customview/test/view/MyTextView.java

+package com.mxdl.customview.test.view;
+
+import android.content.Context;
+import android.util.AttributeSet;
+import android.util.Log;
+import android.view.MotionEvent;
+import android.widget.TextView;
+
+import com.mxdl.customview.util.MotionEventUtil;
+
+/**
+ * Description: <MyTextView><br>
+ * Author:      mxdl<br>
+ * Date:        2019/10/25<br>
+ * Version:     V1.0.0<br>
+ * Update:     <br>
+ */
+public class MyTextView extends android.support.v7.widget.AppCompatTextView {
+    public MyTextView(Context context) {
+        super(context);
+    }
+
+    public MyTextView(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public MyTextView(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    @Override
+    public boolean dispatchTouchEvent(MotionEvent event) {
+        Log.v("MYTAG","TextView dispatchTouchEvent start..."+ MotionEventUtil.getEventType(event));
+        return super.dispatchTouchEvent(event);
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent event) {
+        Log.v("MYTAG","TextView onTouchEvent start..."+ MotionEventUtil.getEventType(event));
+        return super.onTouchEvent(event);
+    }
+
+}

app/src/main/java/com/mxdl/customview/test/view/MyViewPager.java

@@ -11,6 +11,8 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.widget.Scroller;
 
+import com.mxdl.customview.util.MotionEventUtil;
+
 /**
  * Description: <MyViewPager><br>
  * Author:      mxdl<br>
@@ -25,6 +27,8 @@ public class MyViewPager extends ViewGroup {
     private int mChildIndex;
     private Scroller mScroller;
     private VelocityTracker mVelocityTracker;
+    private int mLastXIntercept;
+    private int mLastYIntercept;
 
     public MyViewPager(Context context) {
         super(context);
@@ -54,11 +58,41 @@ public class MyViewPager extends ViewGroup {
     @Override
     protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
         super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+        Log.v("MYTAG", "ViewPager onMeasure start...");
+
+        int widthSpecMode = MeasureSpec.getMode(widthMeasureSpec);
+        int widthSpecSize = MeasureSpec.getSize(widthMeasureSpec);
+        int heightSpecMode = MeasureSpec.getMode(heightMeasureSpec);
+        int heightSpecSize = MeasureSpec.getSize(heightMeasureSpec);
+
+        Log.v("MYTAG","onMeasure width:"+widthSpecSize+";height:"+heightSpecSize);
         measureChildren(widthMeasureSpec, heightMeasureSpec);
+        int measureWidth = 0;
+        int measureHeight = 0;
+        int childCount = getChildCount();
+        if(childCount == 0){
+           setMeasuredDimension(0,0);
+        }else if(widthSpecMode == MeasureSpec.AT_MOST && heightSpecMode == MeasureSpec.AT_MOST){
+            View child = getChildAt(0);
+            measureWidth = child.getMeasuredWidth() * childCount;
+            measureHeight = child.getMeasuredHeight();
+            //setMeasuredDimension(widthSpecSize,heightSpecSize);
+            setMeasuredDimension(measureWidth,measureHeight);
+        }else if(widthSpecMode == MeasureSpec.AT_MOST){
+            View child = getChildAt(0);
+            measureWidth = child.getMeasuredWidth() * childCount;
+            measureHeight = child.getMeasuredHeight();
+            setMeasuredDimension(measureWidth,heightSpecSize);
+        }else if(heightMeasureSpec == MeasureSpec.AT_MOST){
+            View child = getChildAt(0);
+            measureHeight = child.getMeasuredHeight();
+            setMeasuredDimension(widthSpecSize,measureHeight);
+        }
     }
 
     @Override
     protected void onLayout(boolean changed, int l, int t, int r, int b) {
+        Log.v("MYTAG", "ViewPager onLayout start...");
         int childCount = getChildCount();
         int childLeft = 0;
         for (int i = 0; i < childCount; i++) {
@@ -67,30 +101,72 @@ public class MyViewPager extends ViewGroup {
             int measuredHeight = child.getMeasuredHeight();
             child.layout(childLeft, 0, childLeft + measuredWidth, measuredHeight);
 
-            Log.v(TAG, "view count:" + childCount + "|childLeft:" + childLeft + ";view width:" + measuredWidth + ";height:" + measuredHeight + "|scrollX:" + child.getScrollX() + ";scrollY:" + child.getScrollY() + "|x:" + child.getX() + ";y:" + child.getY() + "|" + ";left:" + child.getLeft() + ";top" + child.getTop() + ";right:" + child.getRight() + ";bottom:" + child.getBottom() + "|transtionX:" + child.getTranslationX() + ";transtionY:" + child.getTranslationY());
+            //Log.v(TAG, "view count:" + childCount + "|childLeft:" + childLeft + ";view width:" + measuredWidth + ";height:" + measuredHeight + "|scrollX:" + child.getScrollX() + ";scrollY:" + child.getScrollY() + "|x:" + child.getX() + ";y:" + child.getY() + "|" + ";left:" + child.getLeft() + ";top" + child.getTop() + ";right:" + child.getRight() + ";bottom:" + child.getBottom() + "|transtionX:" + child.getTranslationX() + ";transtionY:" + child.getTranslationY());
             childLeft += measuredWidth;
         }
-        Log.v(TAG, "view pager width：" + getMeasuredWidth() + ";height:" + getMeasuredHeight());
+        //Log.v(TAG, "view pager width：" + getMeasuredWidth() + ";height:" + getMeasuredHeight());
+    }
+
+    @Override
+    public boolean dispatchTouchEvent(MotionEvent ev) {
+        Log.v("MYTAG", "ViewPager dispatchTouchEvent start..." + MotionEventUtil.getEventType(ev));
+        return super.dispatchTouchEvent(ev);
+    }
+
+    @Override
+    public boolean onInterceptTouchEvent(MotionEvent ev) {
+        Log.v("MYTAG", "ViewPager onInterceptTouchEvent start..." + MotionEventUtil.getEventType(ev));
+        boolean intercept = false;
+        int x = (int) ev.getX();
+        int y = (int) ev.getY();
+        switch (ev.getAction()) {
+            case MotionEvent.ACTION_DOWN:
+                intercept = false;
+                if(!mScroller.isFinished()){
+                    mScroller.abortAnimation();
+                    intercept = true;
+                }
+                break;
+            case MotionEvent.ACTION_MOVE:
+                int dx = x - mLastXIntercept;
+                int dy = y - mLastYIntercept;
+                if(Math.abs(dx) > Math.abs(dy)){
+                    intercept = true;
+                }else{
+                    intercept = false;
+                }
+                break;
+            case MotionEvent.ACTION_UP:
+                intercept = false;
+                break;
+        }
+        mLastX = x;
+        mLastY = y;
+        mLastXIntercept = x;
+        mLastYIntercept = y;
+        return intercept;
     }
 
     @Override
     public boolean onTouchEvent(MotionEvent event) {
+        Log.v("MYTAG", "ViewPager onTouchEvent start..." + MotionEventUtil.getEventType(event));
+        Log.v("MYTAG","onTouchEvent width:"+getWidth()+";height:"+getHeight());
+        //Log.v("MYTAG", "ViewPager width:" +getWidth()+";height:"+getHeight()+";measureWidth:"+getMeasuredWidth()+";measureHeigh:"+getMeasuredHeight());
         mVelocityTracker.addMovement(event);
-        boolean consume = false;
         int x = (int) event.getX();
         int y = (int) event.getY();
-        Log.v(TAG, "onTouchEvent x:" + x + ";y:" + y);
+        //Log.v(TAG, "onTouchEvent x:" + x + ";y:" + y);
         switch (event.getAction()) {
             case MotionEvent.ACTION_DOWN:
-                consume = true;
+                if(!mScroller.isFinished()){
+                    mScroller.abortAnimation();
+                }
                 break;
             case MotionEvent.ACTION_MOVE:
                 int dx = x - mLastX;
                 int dy = y - mLastY;
-                if (Math.abs(dx) > Math.abs(dy)) {
+                if(Math.abs(dx) > Math.abs(dy)){
                     scrollBy(-dx, 0);
-                } else {
-                    consume = false;
                 }
                 break;
             case MotionEvent.ACTION_UP:
@@ -105,24 +181,24 @@ public class MyViewPager extends ViewGroup {
                 View child = getChildAt(mChildIndex);
                 int childWidth = child.getMeasuredWidth();
 
-                if(Math.abs(xVelocity) > 50){
-                    mChildIndex = xVelocity > 0 ? mChildIndex - 1:mChildIndex + 1;
-                }else{
+                if (Math.abs(xVelocity) > 50) {
+                    mChildIndex = xVelocity > 0 ? mChildIndex - 1 : mChildIndex + 1;
+                } else {
                     mChildIndex = (scrollX + childWidth / 2) / childWidth;
                 }
 
                 mChildIndex = Math.max(0, Math.min(mChildIndex, getChildCount() - 1));
                 int delx = mChildIndex * childWidth - scrollX;
-                smoothScrollTo(delx,0);
+                smoothScrollTo(delx, 0);
                 mVelocityTracker.clear();
                 break;
         }
         mLastX = x;
         mLastY = y;
-        return consume;
+        return true;
     }
 
-    private void smoothScrollTo(int x,int y) {
+    private void smoothScrollTo(int x, int y) {
         mScroller.startScroll(getScrollX(), getScrollY(), x, y, 500);
         invalidate();
     }

app/src/main/java/com/mxdl/customview/test/view/MyViewPager1.java

+package com.mxdl.customview.test.view;
+
+import android.content.Context;
+import android.os.Build;
+import android.support.annotation.RequiresApi;
+import android.util.AttributeSet;
+import android.view.MotionEvent;
+import android.view.VelocityTracker;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.Scroller;
+
+/**
+ * Description: <MyViewPager1><br>
+ * Author:      mxdl<br>
+ * Date:        2019/10/25<br>
+ * Version:     V1.0.0<br>
+ * Update:     <br>
+ *     1.计算控件的大小
+ *     2.确定子控件的位置
+ *     3.对左滑右滑的事件进行拦截
+ *     4.实现拖动效果
+ *     5.实现翻页效果
+ */
+public class MyViewPager1 extends ViewGroup {
+
+    private Scroller mScroller;
+    private VelocityTracker mVelocityTracker;
+    private int mLastX;
+    private int mLastY;
+    private int mLastXIntercept;
+    private int mLastYIntercept;
+    private int mChildIndex;
+
+    public MyViewPager1(Context context) {
+        super(context);
+        init();
+    }
+
+    public MyViewPager1(Context context, AttributeSet attrs) {
+        super(context, attrs);
+        init();
+    }
+
+    public MyViewPager1(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+        init();
+    }
+
+    @RequiresApi(api = Build.VERSION_CODES.LOLLIPOP)
+    public MyViewPager1(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
+        super(context, attrs, defStyleAttr, defStyleRes);
+        init();
+    }
+
+    public void init() {
+        mScroller = new Scroller(getContext());
+        mVelocityTracker = VelocityTracker.obtain();
+    }
+
+    @Override
+    protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+        super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+        int measureWidth = 0;
+        int measureHeight = 0;
+        int childCount = getChildCount();
+        int widthSpecMode = MeasureSpec.getMode(widthMeasureSpec);
+        int widthSpecSize = MeasureSpec.getSize(widthMeasureSpec);
+        int heightSpecMode = MeasureSpec.getMode(heightMeasureSpec);
+        int heightSpecSize = MeasureSpec.getSize(heightMeasureSpec);
+        measureChildren(widthMeasureSpec, heightMeasureSpec);
+        if (childCount == 0) {
+            setMeasuredDimension(0, 0);
+        } else if (widthSpecMode == MeasureSpec.AT_MOST && heightSpecMode == MeasureSpec.AT_MOST) {
+            View child = getChildAt(0);
+            measureWidth = child.getMeasuredWidth() * childCount;
+            measureHeight = child.getMeasuredHeight();
+            setMeasuredDimension(measureWidth, measureHeight);
+        } else if (widthSpecMode == MeasureSpec.AT_MOST) {
+            View child = getChildAt(0);
+            measureWidth = child.getMeasuredWidth() * childCount;
+            setMeasuredDimension(measureWidth, heightSpecSize);
+        } else if (heightSpecMode == MeasureSpec.AT_MOST) {
+            View child = getChildAt(0);
+            measureHeight = child.getMeasuredHeight();
+            setMeasuredDimension(widthSpecSize, measureHeight);
+        }
+    }
+
+    @Override
+    protected void onLayout(boolean changed, int l, int t, int r, int b) {
+        int childCount = getChildCount();
+        int childLeft = 0;
+        for (int i = 0; i < childCount; i++) {
+            View child = getChildAt(i);
+            int measuredWidth = child.getMeasuredWidth();
+            int measuredHeight = child.getMeasuredHeight();
+            child.layout(childLeft, 0, childLeft + measuredWidth, measuredHeight);
+            childLeft += measuredWidth;
+        }
+    }
+
+    @Override
+    public boolean onInterceptTouchEvent(MotionEvent ev) {
+        boolean intercept = false;
+        int x = (int) ev.getX();
+        int y = (int) ev.getY();
+        switch (ev.getAction()) {
+            case MotionEvent.ACTION_DOWN:
+                intercept = false;
+                if (!mScroller.isFinished()) {
+                    mScroller.abortAnimation();
+                    intercept = true;
+                }
+                break;
+            case MotionEvent.ACTION_MOVE:
+                int dx = x - mLastXIntercept;
+                int dy = y - mLastYIntercept;
+                intercept = false;
+                if (Math.abs(dx) > Math.abs(dy)) {
+                    intercept = true;
+                }
+                break;
+            case MotionEvent.ACTION_UP:
+                intercept = false;
+                break;
+        }
+        mLastX = x;
+        mLastY = y;
+        mLastXIntercept = x;
+        mLastYIntercept = y;
+        return intercept;
+    }
+
+    @Override
+    public boolean onTouchEvent(MotionEvent event) {
+        mVelocityTracker.addMovement(event);
+        int x = (int) event.getX();
+        int y = (int) event.getY();
+        switch (event.getAction()) {
+            case MotionEvent.ACTION_DOWN:
+                if (!mScroller.isFinished()) {
+                    mScroller.abortAnimation();
+                }
+                break;
+            case MotionEvent.ACTION_MOVE:
+                int dx = x - mLastX;
+                scrollBy(-dx, 0);
+                break;
+            case MotionEvent.ACTION_UP:
+                int scrollX = getScrollX();
+                mVelocityTracker.computeCurrentVelocity(1000);
+                float xVelocity = mVelocityTracker.getXVelocity();
+                View child = getChildAt(0);
+                int measuredWidth = child.getMeasuredWidth();
+                if (Math.abs(xVelocity) > 50) {
+                    mChildIndex = xVelocity > 0 ? mChildIndex - 1 : mChildIndex + 1;
+                } else {
+                    mChildIndex = (scrollX + measuredWidth/2)/measuredWidth;
+                }
+                mChildIndex = Math.max(0,Math.min(mChildIndex,getChildCount() -1));
+                int deltaX = mChildIndex * measuredWidth - scrollX;
+                smoothScrollTo(deltaX);
+                mVelocityTracker.clear();
+                break;
+        }
+        mLastX = x;
+        mLastY = y;
+        return true;
+    }
+
+    private void smoothScrollTo(int deltaX) {
+        mScroller.startScroll(getScrollX(),getScrollY(),deltaX,0,500);
+        invalidate();
+    }
+
+    @Override
+    public void computeScroll() {
+        if(mScroller.computeScrollOffset()){
+            scrollTo(mScroller.getCurrX(),mScroller.getCurrY());
+            postInvalidate();
+        }
+    }
+}

app/src/main/java/com/mxdl/customview/util/MotionEventUtil.java

+package com.mxdl.customview.util;
+
+import android.view.MotionEvent;
+
+/**
+ * Description: <MotionEventUtil><br>
+ * Author:      mxdl<br>
+ * Date:        2019/10/25<br>
+ * Version:     V1.0.0<br>
+ * Update:     <br>
+ */
+public class MotionEventUtil {
+    public static String getEventType(MotionEvent ev) {
+        switch (ev.getAction()) {
+            case MotionEvent.ACTION_DOWN:
+                return "action_down";
+            case MotionEvent.ACTION_MOVE:
+                return "action_move";
+            case MotionEvent.ACTION_UP:
+                return "action_down";
+        }
+        return null;
+    }
+}

app/src/main/res/layout/activity_view_pager_test.xml

@@ -3,7 +3,7 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:orientation="vertical">
-<com.mxdl.customview.test.view.MyViewPager
+<com.mxdl.customview.test.view.MyViewPager1
     android:id="@+id/view_my_pager"
     android:layout_width="match_parent"
     android:layout_height="match_parent"/>

app/src/main/res/layout/item_test_view_pager.xml

 <?xml version="1.0" encoding="utf-8"?>
-<TextView
-    android:id="@+id/txt_content"
-    android:layout_width="match_parent"
+<LinearLayout android:layout_width="match_parent"
     android:layout_height="match_parent"
-    xmlns:android="http://schemas.android.com/apk/res/android" />
+    android:orientation="vertical"
+    xmlns:android="http://schemas.android.com/apk/res/android">
+    <com.mxdl.customview.test.view.MyTextView
+        android:id="@+id/txt_content"
+        android:layout_width="match_parent"
+        android:layout_height="300dp"
+        xmlns:android="http://schemas.android.com/apk/res/android" />
+    <com.mxdl.customview.test.view.MyButton
+        android:layout_width="match_parent"
+        android:layout_height="300dp"/>
+</LinearLayout>
+