先上优雅又飘逸的运行效果
darylayout_1.gif
之前做题库项目的时候，有一个这样的需求，当题目是材料题的时候，上面是大段的文字，下面是几个选择题，这就要求上面的材料部分可以上下滚动查看，下面的选择题可以左右滑动查看，所以需要这样的自定义view。
实现前的分析
- 要想同时改变上面部分和下面部分的高度，就不能用DrawLayout那样的侧滑View，因为DrawLayout底部和上面是互不影响的两层。
- 外层布局我用RelativeLayout,然后通过LayoutParams设置上面部分的高度，下面部分的即为外层RelativeLayout的高度减去上面部分高度
- 通过拖动中间的箭头图标来改变上面部分的高度。
使用方式
DragLayout所用到的布局
DrayLayout用到的attrs
由于DrayLayout的代码比较少，这里就直接粘了出来
package com.example.idea.draglayout.view;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.RectF;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.RelativeLayout;
import com.example.idea.draglayout.R;
import com.example.idea.draglayout.utils.DpUtils;
import com.example.idea.draglayout.utils.LogUtils;
/**
* Created by Deemo on 15/10/16.
*/
public class DragLayout extends RelativeLayout {
//默认高度
private final int DEFAULT_HEIGHT_DP = 240;
private RelativeLayout mRlContainerTop;
private RelativeLayout mRlContainerBottom;
private ImageView mIvThumb;
private int resTop, resBottom;
private int type;
private Context mContext;
//触发移动事件的最短距离，如果小于这个距离就不触发移动控件，如viewpager就是用这个距离来判断用户是否翻页
private int mTouchSlop;
private float mDownX, mDownY, mMoveY;
private boolean isTouchThumb;
private boolean isTendToMove;
private float mThumbMinY;
private int mBottomContentViewHeight;
private int mLastBottomTop;
public DragLayout(Context context) {
this(context, null);
}
public DragLayout(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public DragLayout(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
//自定义控件的属性
TypedArray array = context.obtainStyledAttributes(attrs, R.styleable.DragLayout, defStyleAttr, 0);
resTop = array.getResourceId(R.styleable.DragLayout_layout_top, 0);
resBottom = array.getResourceId(R.styleable.DragLayout_layout_bottom, 0);
setType(array.getInteger(R.styleable.DragLayout_questionType, 0));
array.recycle();
init(context);
}
private void init(Context context) {
mContext = context;
LayoutInflater.from(context).inflate(R.layout.view_draglayout, this, true);
mRlContainerTop = (RelativeLayout) findViewById(R.id.rl_container_top);
mRlContainerBottom = (RelativeLayout) findViewById(R.id.rl_container_bottom);
mIvThumb = (ImageView) findViewById(R.id.iv_thumb);
setTopAndBottomLayout(resTop, resBottom);
mTouchSlop = ViewConfiguration.get(context).getScaledTouchSlop();
initHeight();
}
private void initHeight() {
float defaultHeight = DpUtils.dp2px(mContext.getResources(), DEFAULT_HEIGHT_DP);
//通过LayoutParams来设置上面部分的高度
ViewGroup.LayoutParams layoutParams = mRlContainerTop.getLayoutParams();
layoutParams.height = (int) defaultHeight;
mRlContainerTop.setLayoutParams(layoutParams);
}
public void setType(int type) {
this.type = type;
}
public void setTopLayout(View view) {
if (view != null) {
mRlContainerTop.addView(view);
}
}
public void setBottomLayout(final View view) {
if (view != null) {
mRlContainerBottom.addView(view);
mIvThumb.setVisibility(View.VISIBLE);
if (view.getMeasuredHeight() == 0) {
view.measure(0, 0);
}
mBottomContentViewHeight = view.getMeasuredHeight();
} else {
mRlContainerTop.setLayoutParams(new LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
mRlContainerBottom.setVisibility(View.GONE);
mIvThumb.setVisibility(View.GONE);
}
}
public void setTopAndBottomLayout(int top, int bottom) {
if (top != 0) {
View topView = LayoutInflater.from(getContext()).inflate(top, null);
setTopLayout(topView);
}
if (bottom != 0) {
View bottomView = LayoutInflater.from(getContext()).inflate(bottom, null);
setTopLayout(bottomView);
}
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
LogUtils.d(this, String.format("DragLayout w=%d, h=%d, ow=%d, oh=%d", w, h, oldw, oldh));
}
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
switch (ev.getAction()) {
case MotionEvent.ACTION_DOWN:
mDownX = ev.getX();
mDownY = ev.getY();
mMoveY = mDownY;
isTouchThumb = isTouchThumb();
if (isTouchThumb())
return true;
return super.dispatchTouchEvent(ev);
case MotionEvent.ACTION_MOVE:
float moveY = ev.getY();
if (isTouchThumb) {
float movedY = moveY - mMoveY;
if (!isTendToMove) {
isTendToMove = isTendToMove(movedY);
}
if (isTendToMove) {
tryToMoveThumb(movedY);
mMoveY = moveY;
return true;
}
}
break;
case MotionEvent.ACTION_UP:
case MotionEvent.ACTION_CANCEL:
reset();
break;
}
return super.dispatchTouchEvent(ev);
}
private void reset() {
isTendToMove = false;
}
/**
* 拖动图片的有效按压部分
*/
private boolean isTouchThumb() {
RectF rect = new RectF(mIvThumb.getLeft(), mIvThumb.getTop(), mIvThumb.getRight(), mIvThumb.getBottom());
return rect.contains(mDownX, mDownY);
}
private boolean isTendToMove(float y) {
return Math.abs(mDownY - y) >= mTouchSlop;
}
/**
* 拖动范围限制,拖动的图片不能划出界面
*
* @param movedY
*/
private void tryToMoveThumb(float movedY) {
boolean canMove = (mIvThumb.getBottom() + movedY) < getHeight() && (mIvThumb.getTop() + movedY) > mThumbMinY;
if (canMove) {
mIvThumb.offsetTopAndBottom((int) movedY);
adjustTopAndBottom((int) movedY);
mLastBottomTop = mRlContainerBottom.getTop();
}
}
/**
* 改变上面部分高度
*
* @param movedY
*/
public void adjustTopAndBottom(int movedY) {
ViewGroup.LayoutParams layoutParams = mRlContainerTop.getLayoutParams();
layoutParams.height += movedY;
if (layoutParams.height < 0) {
layoutParams.height = 0;
}
mRlContainerTop.setLayoutParams(layoutParams);
LogUtils.d(this, "adjustTopAndBottom" + movedY + ", mRlytContainerTop=" + mRlContainerTop);
}
protected final int getBottomContentViewHeight() {
return mBottomContentViewHeight;
}
protected int getBottomTop() {
return mLastBottomTop;
}
}
存在问题
由于动态改变LayoutParams的高度，导致TopLayout和BottmoLayouy的子view的onMeasure()和onLayout方法不断执行，从而在2.3版本性能不好的安卓手机上测试，会有卡顿感觉。
ok，基本完工了，后期如果有了更好的实现方式再来更新。
源码地址 https://github.com/idea007/DragLayout