前言
前面在介绍控件TabLayout控件和CoordinatorLayout使用的时候说了下实现京东、天猫详情页面的效果,今天要说的是优化版,是我们线上实现的效果,首先看一张效果:
项目结构分析
首先我们来分析一下要实现上面的效果,我们需要怎么做。顶部是一个可以滑动切换Tab,可以用ViewPager+Fragment实现,也可以使用系统的TabLayout控件实现;而下面的 View是一个可以滑动拖动效果的View,可以采用网上一个叫做DragLayout的控件,我这里是自己实现了一个,主要是通过对View的事件分发的一些处理;然后滑动到下面就是一个图文详情的View(Fragment),本页面包含两个界面:详情页面和参数页面;最后是评价的View(Fragment)。经过上面的分析,我们的界面至少需要4个Fragement,首先来看一下项目结构:
代码讲解
代码比较多,这里只讲解几个核心的方法类。首先我们来看一下我们自己是的这个具有阻尼效果的View,我们知道要实现的效果,我们需要对View的事件做一个全面的实现。这里首先说一下View的事件分发的流程:
onInterceptTouchEvent() >dispatchTouchEvent() >onTouchEvent();
首先我们需要对View传过来的事件做一个拦截:
ensureTarget(); if (null == mTarget) { return false; } if (!isEnabled()) { return false; } final int aciton = MotionEventCompat.getActionMasked(ev); boolean shouldIntercept = false; switch (aciton) { case MotionEvent.ACTION_DOWN: { mInitMotionX = ev.getX(); mInitMotionY = ev.getY(); shouldIntercept = false; break; } case MotionEvent.ACTION_MOVE: { final float x = ev.getX(); final float y = ev.getY(); final float xDiff = x - mInitMotionX; final float yDiff = y - mInitMotionY; if (canChildScrollVertically((int) yDiff)) { shouldIntercept = false; } else { final float xDiffabs = Math.abs(xDiff); final float yDiffabs = Math.abs(yDiff); if (yDiffabs > mTouchSlop && yDiffabs >= xDiffabs && !(mStatus == Status.CLOSE && yDiff > 0 || mStatus == Status.OPEN && yDiff < 0)) { shouldIntercept = true; } } break; } case MotionEvent.ACTION_UP: case MotionEvent.ACTION_CANCEL: { shouldIntercept = false; break; } } return shouldIntercept;
最后转发给onTouchEvent
ensureTarget(); if (null == mTarget) { return false; } if (!isEnabled()) { return false; } boolean wantTouch = true; final int action = MotionEventCompat.getActionMasked(ev); switch (action) { case MotionEvent.ACTION_DOWN: { if (mTarget instanceof View) { wantTouch = true; } break; } case MotionEvent.ACTION_MOVE: { final float y = ev.getY(); final float yDiff = y - mInitMotionY; if (canChildScrollVertically(((int) yDiff))) { wantTouch = false; } else { processTouchEvent(yDiff); wantTouch = true; } break; } case MotionEvent.ACTION_UP: case MotionEvent.ACTION_CANCEL: { finishTouchEvent(); wantTouch = false; break; } } return wantTouch;
滑动事件完了之后我们需要调用request方法对View做一个重绘:
final int left = l; final int right = r; int top; int bottom; final int offset = (int) mSlideOffset; View child; for (int i = 0; i < getChildCount(); i++) { child = getChildAt(i); if (child.getVisibility() == GONE) { continue; } if (child == mBehindView) { top = b + offset; bottom = top + b - t; } else { top = t + offset; bottom = b + offset; } child.layout(left, top, right, bottom); }
上下滑动也是涉及到两个界面:mFrontView和mBehindView,然后通过判断滑动事件来显示哪一个View。具体看代码:
package com.xzh.gooddetail.view;import android.animation.Animator;import android.animation.AnimatorListenerAdapter;import android.animation.ValueAnimator;import android.content.Context;import android.content.res.TypedArray;import android.os.Parcel;import android.os.Parcelable;import android.support.v4.view.MotionEventCompat;import android.support.v4.view.ViewCompat;import android.util.AttributeSet;import android.view.MotionEvent;import android.view.View;import android.view.ViewConfiguration;import android.view.ViewGroup;import android.widget.AbsListView;import android.widget.FrameLayout;import android.widget.LinearLayout;import android.widget.RelativeLayout;import com.xzh.gooddetail.R;public class SlideDetailsLayout extends ViewGroup { public interface OnSlideDetailsListener { void onStatusChanged(Status status); } public enum Status { CLOSE, OPEN; public static Status valueOf(int stats) { if (0 == stats) { return CLOSE; } else if (1 == stats) { return OPEN; } else { return CLOSE; } } } private static final float DEFAULT_PERCENT = 0.2f; private static final int DEFAULT_DURATION = 300; private View mFrontView; private View mBehindView; private float mTouchSlop; private float mInitMotionY; private float mInitMotionX; private View mTarget; private float mSlideOffset; private Status mStatus = Status.CLOSE; private boolean isFirstShowBehindView = true; private float mPercent = DEFAULT_PERCENT; private long mDuration = DEFAULT_DURATION; private int mDefaultPanel = 0; private OnSlideDetailsListener mOnSlideDetailsListener; public SlideDetailsLayout(Context context) { this(context, null); } public SlideDetailsLayout(Context context, AttributeSet attrs) { this(context, attrs, 0); } public SlideDetailsLayout(Context context, AttributeSet attrs, int defStyleAttr) { super(context, attrs, defStyleAttr); TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.SlideDetailsLayout, defStyleAttr, 0); mPercent = a.getFloat(R.styleable.SlideDetailsLayout_percent, DEFAULT_PERCENT); mDuration = a.getInt(R.styleable.SlideDetailsLayout_duration, DEFAULT_DURATION); mDefaultPanel = a.getInt(R.styleable.SlideDetailsLayout_default_panel, 0); a.recycle(); mTouchSlop = ViewConfiguration.get(getContext()).getScaledTouchSlop(); } public void setOnSlideDetailsListener(OnSlideDetailsListener listener) { this.mOnSlideDetailsListener = listener; } public void smoothOpen(boolean smooth) { if (mStatus != Status.OPEN) { mStatus = Status.OPEN; final float height = -getMeasuredHeight(); animatorSwitch(0, height, true, smooth ? mDuration : 0); } } public void smoothClose(boolean smooth) { if (mStatus != Status.CLOSE) { mStatus = Status.CLOSE; final float height = -getMeasuredHeight(); animatorSwitch(height, 0, true, smooth ? mDuration : 0); } } @Override protected LayoutParams generateDefaultLayoutParams() { return new MarginLayoutParams(MarginLayoutParams.WRAP_CONTENT, MarginLayoutParams.WRAP_CONTENT); } @Override public LayoutParams generateLayoutParams(AttributeSet attrs) { return new MarginLayoutParams(getContext(), attrs); } @Override protected LayoutParams generateLayoutParams(LayoutParams p) { return new MarginLayoutParams(p); } @Override protected void onFinishInflate() { final int childCount = getChildCount(); if (1 >= childCount) { throw new RuntimeException("SlideDetailsLayout only accept childs more than 1!!"); } mFrontView = getChildAt(0); mBehindView = getChildAt(1); if (mDefaultPanel == 1) { post(new Runnable() { @Override public void run() { smoothOpen(false); } }); } } @Override protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) { final int pWidth = MeasureSpec.getSize(widthMeasureSpec); final int pHeight = MeasureSpec.getSize(heightMeasureSpec); final int childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(pWidth, MeasureSpec.EXACTLY); final int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(pHeight, MeasureSpec.EXACTLY); View child; for (int i = 0; i < getChildCount(); i++) { child = getChildAt(i); if (child.getVisibility() == GONE) { continue; } measureChild(child, childWidthMeasureSpec, childHeightMeasureSpec); } setMeasuredDimension(pWidth, pHeight); } @Override protected void onLayout(boolean changed, int l, int t, int r, int b) { final int left = l; final int right = r; int top; int bottom; final int offset = (int) mSlideOffset; View child; for (int i = 0; i < getChildCount(); i++) { child = getChildAt(i); if (child.getVisibility() == GONE) { continue; } if (child == mBehindView) { top = b + offset; bottom = top + b - t; } else { top = t + offset; bottom = b + offset; } child.layout(left, top, right, bottom); } } @Override public boolean onInterceptTouchEvent(MotionEvent ev) { ensureTarget(); if (null == mTarget) { return false; } if (!isEnabled()) { return false; } final int aciton = MotionEventCompat.getActionMasked(ev); boolean shouldIntercept = false; switch (aciton) { case MotionEvent.ACTION_DOWN: { mInitMotionX = ev.getX(); mInitMotionY = ev.getY(); shouldIntercept = false; break; } case MotionEvent.ACTION_MOVE: { final float x = ev.getX(); final float y = ev.getY(); final float xDiff = x - mInitMotionX; final float yDiff = y - mInitMotionY; if (canChildScrollVertically((int) yDiff)) { shouldIntercept = false; } else { final float xDiffabs = Math.abs(xDiff); final float yDiffabs = Math.abs(yDiff); if (yDiffabs > mTouchSlop && yDiffabs >= xDiffabs && !(mStatus == Status.CLOSE && yDiff > 0 || mStatus == Status.OPEN && yDiff < 0)) { shouldIntercept = true; } } break; } case MotionEvent.ACTION_UP: case MotionEvent.ACTION_CANCEL: { shouldIntercept = false; break; } } return shouldIntercept; } @Override public boolean onTouchEvent(MotionEvent ev) { ensureTarget(); if (null == mTarget) { return false; } if (!isEnabled()) { return false; } boolean wantTouch = true; final int action = MotionEventCompat.getActionMasked(ev); switch (action) { case MotionEvent.ACTION_DOWN: { if (mTarget instanceof View) { wantTouch = true; } break; } case MotionEvent.ACTION_MOVE: { final float y = ev.getY(); final float yDiff = y - mInitMotionY; if (canChildScrollVertically(((int) yDiff))) { wantTouch = false; } else { processTouchEvent(yDiff); wantTouch = true; } break; } case MotionEvent.ACTION_UP: case MotionEvent.ACTION_CANCEL: { finishTouchEvent(); wantTouch = false; break; } } return wantTouch; } private void processTouchEvent(final float offset) { if (Math.abs(offset) < mTouchSlop) { return; } final float oldOffset = mSlideOffset; if (mStatus == Status.CLOSE) { // reset if pull down if (offset >= 0) { mSlideOffset = 0; } else { mSlideOffset = offset; } if (mSlideOffset == oldOffset) { return; } } else if (mStatus == Status.OPEN) { final float pHeight = -getMeasuredHeight(); if (offset <= 0) { mSlideOffset = pHeight; } else { final float newOffset = pHeight + offset; mSlideOffset = newOffset; } if (mSlideOffset == oldOffset) { return; } } requestLayout(); } private void finishTouchEvent() { final int pHeight = getMeasuredHeight(); final int percent = (int) (pHeight * mPercent); final float offset = mSlideOffset; boolean changed = false; if (Status.CLOSE == mStatus) { if (offset <= -percent) { mSlideOffset = -pHeight; mStatus = Status.OPEN; changed = true; } else { mSlideOffset = 0; } } else if (Status.OPEN == mStatus) { if ((offset + pHeight) >= percent) { mSlideOffset = 0; mStatus = Status.CLOSE; changed = true; } else { mSlideOffset = -pHeight; } } animatorSwitch(offset, mSlideOffset, changed); } private void animatorSwitch(final float start, final float end) { animatorSwitch(start, end, true, mDuration); } private void animatorSwitch(final float start, final float end, final long duration) { animatorSwitch(start, end, true, duration); } private void animatorSwitch(final float start, final float end, final boolean changed) { animatorSwitch(start, end, changed, mDuration); } private void animatorSwitch(final float start, final float end, final boolean changed, final long duration) { ValueAnimator animator = ValueAnimator.ofFloat(start, end); animator.addUpdateListener(new ValueAnimator.AnimatorUpdateListener() { @Override public void onAnimationUpdate(ValueAnimator animation) { mSlideOffset = (float) animation.getAnimatedValue(); requestLayout(); } }); animator.addListener(new AnimatorListenerAdapter() { @Override public void onAnimationEnd(Animator animation) { super.onAnimationEnd(animation); if (changed) { if (mStatus == Status.OPEN) { checkAndFirstOpenPanel(); } if (null != mOnSlideDetailsListener) { mOnSlideDetailsListener.onStatusChanged(mStatus); } } } }); animator.setDuration(duration); animator.start(); } private void checkAndFirstOpenPanel() { if (isFirstShowBehindView) { isFirstShowBehindView = false; mBehindView.setVisibility(VISIBLE); } } private void ensureTarget() { if (mStatus == Status.CLOSE) { mTarget = mFrontView; } else { mTarget = mBehindView; } } protected boolean canChildScrollVertically(int direction) { if (mTarget instanceof AbsListView) { return canListViewSroll((AbsListView) mTarget); } else if (mTarget instanceof FrameLayout || mTarget instanceof RelativeLayout || mTarget instanceof LinearLayout) { View child; for (int i = 0; i < ((ViewGroup) mTarget).getChildCount(); i++) { child = ((ViewGroup) mTarget).getChildAt(i); if (child instanceof AbsListView) { return canListViewSroll((AbsListView) child); } } } if (android.os.Build.VERSION.SDK_INT < 14) { return ViewCompat.canScrollVertically(mTarget, -direction) || mTarget.getScrollY() > 0; } else { return ViewCompat.canScrollVertically(mTarget, -direction); } } protected boolean canListViewSroll(AbsListView absListView) { if (mStatus == Status.OPEN) { return absListView.getChildCount() > 0 && (absListView.getFirstVisiblePosition() > 0 || absListView.getChildAt(0) .getTop() < absListView.getPaddingTop()); } else { final int count = absListView.getChildCount(); return count > 0 && (absListView.getLastVisiblePosition() < count - 1 || absListView.getChildAt(count - 1) .getBottom() > absListView.getMeasuredHeight()); } } @Override protected Parcelable onSaveInstanceState() { SavedState ss = new SavedState(super.onSaveInstanceState()); ss.offset = mSlideOffset; ss.status = mStatus.ordinal(); return ss; } @Override protected void onRestoreInstanceState(Parcelable state) { SavedState ss = (SavedState) state; super.onRestoreInstanceState(ss.getSuperState()); mSlideOffset = ss.offset; mStatus = Status.valueOf(ss.status); if (mStatus == Status.OPEN) { mBehindView.setVisibility(VISIBLE); } requestLayout(); } static class SavedState extends BaseSavedState { private float offset; private int status; public SavedState(Parcel source) { super(source); offset = source.readFloat(); status = source.readInt(); } public SavedState(Parcelable superState) { super(superState); } @Override public void writeToParcel(Parcel out, int flags) { super.writeToParcel(out, flags); out.writeFloat(offset); out.writeInt(status); } public static final Creator<SavedState> CREATOR = new Creator<SavedState>() { public SavedState createFromParcel(Parcel in) { return new SavedState(in); } public SavedState[] newArray(int size) { return new SavedState[size]; } }; }}
接下来就是一些Fragment等的页面填充,也没啥好讲的,代码又很多可以优化的地方,在优化的地方,笔者也列出了优化的方案,大家可以根据自己的实际情况做页面级的优化。
源码下载:http://xiazai.VeVB.COm/201701/yuanma/AndriodGoodDetail(VeVB.COm).rar
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持武林网。
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