This article shares the specific code of Android refresh loading framework for your reference. The specific content is as follows
1. Define an interface to control pull-down and pull-up
public interface Pullable {
/**
* Is it possible to pull down
*/
boolean canPullDown();
/**
* Is it possible to pull up
*/
boolean canPullUp();
}
2. Define a refresh loading layout
public class PullToRefreshLayout extends RelativeLayout {
/**
* head
*/
private View headView;//Head view private ImageView headIv;//Head icon private TextView headTv;//Initial text private int headHeight;//Height private float headBorder;//Head critical /**
* pull
*/
private View pullView;//Pull view private int pullHeight;//Pull height private int pullWidth;//Width
/**
* Final
*/
private View footView;//Tail view private ImageView footIv;//Tail icon private TextView footTv;//The end text private int footHeight;//Tail height private float footBorder;//Tail critical
/**
* state
*/
public static final int INIT = 0;//initial public static final int RELEASE_TO_REFRESH = 1;//Release refresh public static final int REFRESHING = 2;//Refreshing public static final int RELEASE_TO_LOAD = 3;//Release load public static final int LOADING = 4;//Loading public static final int DONE = 5;//Finish private int state = INIT;
/**
* Interface
*/
private OnRefreshListener mListener;
private float downY;//Y coordinate when pressed private float lastY;//Previous Y coordinate private float pullDownY = 0;// Pull down offset private float pullUpY = 0;//Pull-up offset private int offset;//Offset
/**
* Animation
*/
private RotateAnimation rotateAnimation;
/**
* Thread
*/
private Handler handler = new Handler() {
@Override
public void handleMessage(Message msg) {
(msg);
if (msg != null) {
switch () {
case 1:
();
break;
case 2:
();
break;
default:
break;
}
pullDownY = 0;
pullUpY = 0;
requestLayout();
state = INIT;
refreshViewByState();
isTouch = true;
}
}
};
/**
* First execution layout
*/
private boolean isLayout = false;
/**
* Slide during refresh
*/
private boolean isTouch = false;
/**
* The ratio of the sliding distance between the finger and the sliding distance between the pull-down head will change with the tangent function.
*/
private float radio = 2;
/**
* Filter multi-touch
*/
private int mEvents;
/**
* These two variables are used to control the direction of pull. If there is no control, it cannot be pulled up when the situation meets the situation.
*/
private boolean canPullDown = true;
private boolean canPullUp = true;
public void setOnRefreshListener(OnRefreshListener listener) {
mListener = listener;
}
public PullToRefreshLayout(Context context) {
super(context);
initView(context);
}
public PullToRefreshLayout(Context context, AttributeSet attrs) {
super(context, attrs);
initView(context);
}
public PullToRefreshLayout(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
initView(context);
}
private void initView(Context context) {
rotateAnimation = (RotateAnimation) (context, );
}
private void refreshViewByState() {
switch (state) {
case INIT:
// Initial state of pull-down layout ("Drag down to refresh the displayed picture");
("Drive down to refresh");
// Initial state of pull-up layout ("Pull up to load the displayed picture");
("Pull-up Loading");
break;
case RELEASE_TO_REFRESH:
// Release refresh status ("Release refreshed image");
("Release Refresh");
break;
case REFRESHING:
// Refreshing status ("Refreshing the displayed image");
("Refreshing");
break;
case RELEASE_TO_LOAD:
// Release the loading state ("Release the picture loaded");
("Release Loading");
break;
case LOADING:
// Loading status ("The displayed picture is loading");
("Loading");
break;
case DONE:
// After refreshing or loading, do nothing break;
}
}
/**
* No limit on pull-up or pull-down
*/
private void releasePull() {
canPullDown = true;
canPullUp = true;
}
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
switch (()) {
case MotionEvent.ACTION_DOWN:
downY = ();
lastY = downY;
mEvents = 0;
releasePull();
if (state != REFRESHING && state != LOADING) {
isTouch = true;
}
break;
case MotionEvent.ACTION_POINTER_DOWN:
case MotionEvent.ACTION_POINTER_UP:
// Filter multi-touch mEvents = -1;
break;
case MotionEvent.ACTION_MOVE:
if (mEvents == 0) {
if (pullDownY > 0 || (((Pullable) pullView).canPullDown()
&& canPullDown && state != LOADING && state != REFRESHING)) {
// Can be pulled down, but cannot be pulled down when loading // Reduce the actual sliding distance, causing the feeling of pulling with force pullDownY = pullDownY + (() - lastY) / radio;
if (pullDownY < 0) {
pullDownY = 0;
canPullDown = false;
canPullUp = true;
}
if (pullDownY > getMeasuredHeight()) {
pullDownY = getMeasuredHeight();
}
if (state == REFRESHING) {
// Touch to move while refreshing isTouch = false;
}
} else if (pullUpY < 0
|| (((Pullable) pullView).canPullUp() && canPullUp && state != REFRESHING && state != LOADING)) {
// Can be pulled up, but cannot be pulled up when refreshing pullUpY = pullUpY + (() - lastY) / radio;
if (pullUpY > 0) {
pullUpY = 0;
canPullDown = true;
canPullUp = false;
}
if (pullUpY < -getMeasuredHeight()) {
pullUpY = -getMeasuredHeight();
}
if (state == LOADING) {
// Touch and move while loading isTouch = false;
}
}
}
if (isTouch) {
lastY = ();
if (pullDownY > 0 || pullUpY < 0) {
requestLayout();
}
if (pullDownY > 0) {
if (pullDownY <= headBorder && (state == RELEASE_TO_REFRESH || state == DONE)) {
// If the pull-down distance does not reach the refresh distance and the current state is releasing refresh, change the state to pull-down refresh state = INIT;
refreshViewByState();
}
if (pullDownY >= headBorder && state == INIT) {
// If the pull-down distance reaches the refresh distance and the current state is the initial state refresh, change the state to release refresh state = RELEASE_TO_REFRESH;
refreshViewByState();
}
} else if (pullUpY < 0) {
// The following is to judge the loading of pullup, the same as above, note that pullUpY is a negative value if (-pullUpY <= footBorder && (state == RELEASE_TO_LOAD || state == DONE)) {
state = INIT;
refreshViewByState();
}
// Pull-up operation if (-pullUpY >= footBorder && state == INIT) {
state = RELEASE_TO_LOAD;
refreshViewByState();
}
}
// Because refresh and load operations cannot be performed at the same time, pullDownY and pullUpY will not be 0 at the same time, so here (pullDownY + // (pullUpY)) can not distinguish the current status if ((pullDownY + (pullUpY)) > 8) {
// Prevent long press and click events from accidentally triggering during pull-down (MotionEvent.ACTION_CANCEL);
}
}
break;
case MotionEvent.ACTION_UP:
if (pullDownY > headBorder || -pullUpY > footBorder) {
// Pull down when refreshing (pull up when loading), and after release, pull down head (pull up head) will not be hidden isTouch = false;
}
if (state == RELEASE_TO_REFRESH) {
state = REFRESHING;
refreshViewByState();
// Refresh operation if (mListener != null) {
canPullDown = false;
pullDownY = headBorder;
pullUpY = 0;
requestLayout();
(rotateAnimation);
(this);
}
} else if (state == RELEASE_TO_LOAD) {
state = LOADING;
refreshViewByState();
// Loading operation if (mListener != null) {
canPullUp = false;
pullDownY = 0;
pullUpY = -footBorder;
requestLayout();
(rotateAnimation);
(this);
}
} else {
pullDownY = 0;
pullUpY = 0;
requestLayout();
}
default:
break;
}
// Event distribution is handed over to the parent class (ev);
return true;
}
public void hideHeadView() {
(1);
}
public void hideFootView() {
(2);
}
private void initView() {
// Initialize the drop-down layout headIv = (ImageView) (.iv_head);
headTv = (TextView) (.tv_head);
//Initialize the pull-up layout footIv = (ImageView) (.iv_foot);
footTv = (TextView) (.tv_foot);
refreshViewByState();
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
if (!isLayout) {
// This is the first time I come in to do some initialization headView = getChildAt(0);
pullView = getChildAt(1);
footView = getChildAt(2);
headBorder = ((ViewGroup) headView).getChildAt(0).getMeasuredHeight();
footBorder = ((ViewGroup) footView).getChildAt(0).getMeasuredHeight();
headHeight = ();
pullHeight = ();
footHeight = ();
pullWidth = ();
initView();
isLayout = true;
}
// Change the layout of the subcontrol, use (pullDownY + pullUpY) as the offset, so that the current state can be distinguished without distinguishing offset = (int) (pullDownY + pullUpY);
(0, -headHeight + offset, pullWidth, offset);
(0, offset, pullWidth, pullHeight + offset);
(0, pullHeight + offset, pullWidth, pullHeight + footHeight + offset);
}
public interface OnRefreshListener {
void onRefresh(PullToRefreshLayout pullToRefreshLayout);
void onLoadMore(PullToRefreshLayout pullToRefreshLayout);
}
}
3. Custom View
ListView
public class PullableListView extends ListView implements Pullable {
public PullableListView(Context context) {
super(context);
}
public PullableListView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public PullableListView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
public boolean canPullDown() {
if (getCount() == 0) {
// When there is no item, you can also pull down and refresh return false;
} else if (getFirstVisiblePosition() == 0 && getChildAt(0).getTop() >= 0) {
// Slide to the top of the ListView return true;
} else
return false;
}
@Override
public boolean canPullUp() {
if (getCount() == 0) {
// You can also load when there is no item return false;
} else if (getLastVisiblePosition() == (getCount() - 1)) {
// Slide to the bottom if (getChildAt(getLastVisiblePosition() - getFirstVisiblePosition()) != null
&& getChildAt(getLastVisiblePosition() - getFirstVisiblePosition())
.getBottom() <= getMeasuredHeight())
return true;
}
return false;
}
}
GridView
public class PullableGridView extends GridView implements Pullable {
public PullableGridView(Context context) {
super(context);
}
public PullableGridView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public PullableGridView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
public boolean canPullDown() {
if (getCount() == 0) {
// When there is no item, you can also pull down and refresh return false;
} else if (getFirstVisiblePosition() == 0
&& getChildAt(0).getTop() >= 0) {
// Slide to the top return true;
} else
return false;
}
@Override
public boolean canPullUp() {
if (getCount() == 0) {
// You can also load when there is no item return false;
} else if (getLastVisiblePosition() == (getCount() - 1)) {
// Slide to the bottom if (getChildAt(getLastVisiblePosition() - getFirstVisiblePosition()) != null
&& getChildAt(
getLastVisiblePosition()
- getFirstVisiblePosition()).getBottom() <= getMeasuredHeight())
return true;
}
return false;
}
}
RecyclerView
public class PullableRecyclerView extends RecyclerView implements Pullable {
public PullableRecyclerView(Context context) {
super(context);
}
public PullableRecyclerView(Context context, @Nullable AttributeSet attrs) {
super(context, attrs);
}
public PullableRecyclerView(Context context, @Nullable AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
public boolean canPullDown() {
layoutManager = getLayoutManager();
if (layoutManager instanceof LinearLayoutManager) {
LinearLayoutManager linearLayoutManager = (LinearLayoutManager) layoutManager;
if (() == 0) {
return false;
} else if (() == 0 && (0).getTop() >= 0) {
return true;
} else {
return false;
}
} else if (layoutManager instanceof StaggeredGridLayoutManager) {
StaggeredGridLayoutManager staggeredGridLayoutManager = (StaggeredGridLayoutManager) layoutManager;
if (() == 0) {
return false;
} else {
int[] firstVisibleItems = null;
firstVisibleItems = (firstVisibleItems);
if (firstVisibleItems != null && > 0) {
if (() + firstVisibleItems[0] == ()) {
return true;
}
}
}
}
return false;
}
@Override
public boolean canPullUp() {
layoutManager = getLayoutManager();
if (layoutManager instanceof LinearLayoutManager) {
LinearLayoutManager linearLayoutManager = (LinearLayoutManager) layoutManager;
if (() == 0) {
return false;
} else if (() == (() - 1)) {
if ((() - ()) != null
&& (() - ()).getBottom() <= getMeasuredHeight()) {
return true;
}
}
} else if (layoutManager instanceof StaggeredGridLayoutManager) {
StaggeredGridLayoutManager staggeredGridLayoutManager = (StaggeredGridLayoutManager) layoutManager;
if (() == 0) {
return false;
} else {
int[] lastPositions = new int[()];
lastPositions = (lastPositions);
if (findMax(lastPositions) >= () - 1) {
return true;
}
}
}
return false;
}
private int findMax(int[] lastPositions) {
int max = lastPositions[0];
for (int value : lastPositions) {
if (value > max) {
max = value;
}
}
return max;
}
}
ExpandableListView
public class PullableExpandableListView extends ExpandableListView implements
Pullable {
public PullableExpandableListView(Context context) {
super(context);
}
public PullableExpandableListView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public PullableExpandableListView(Context context, AttributeSet attrs,
int defStyle) {
super(context, attrs, defStyle);
}
@Override
public boolean canPullDown() {
if (getCount() == 0) {
// When there is no item, you can also pull down and refresh return false;
} else if (getFirstVisiblePosition() == 0
&& getChildAt(0).getTop() >= 0) {
// Slide to the top return true;
} else
return false;
}
@Override
public boolean canPullUp() {
if (getCount() == 0) {
// You can also load when there is no item return false;
} else if (getLastVisiblePosition() == (getCount() - 1)) {
// Slide to the bottom if (getChildAt(getLastVisiblePosition() - getFirstVisiblePosition()) != null
&& getChildAt(
getLastVisiblePosition()
- getFirstVisiblePosition()).getBottom() <= getMeasuredHeight())
return true;
}
return false;
}
}
ScrollView
public class PullableScrollView extends ScrollView implements Pullable {
public PullableScrollView(Context context) {
super(context);
}
public PullableScrollView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public PullableScrollView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
public boolean canPullDown() {
if (getScrollY() == 0)
return true;
else
return false;
}
@Override
public boolean canPullUp() {
if (getScrollY() >= (getChildAt(0).getHeight() - getMeasuredHeight()))
return true;
else
return false;
}
}
WebView
public class PullableWebView extends WebView implements Pullable {
public PullableWebView(Context context) {
super(context);
}
public PullableWebView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public PullableWebView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
public boolean canPullDown() {
if (getScrollY() == 0)
return true;
else
return false;
}
@Override
public boolean canPullUp() {
if (getScrollY() >= getContentHeight() * getScale()
- getMeasuredHeight())
return true;
else
return false;
}
}
ImageView
public class PullableImageView extends ImageView implements Pullable
{
public PullableImageView(Context context)
{
super(context);
}
public PullableImageView(Context context, AttributeSet attrs)
{
super(context, attrs);
}
public PullableImageView(Context context, AttributeSet attrs, int defStyle)
{
super(context, attrs, defStyle);
}
@Override
public boolean canPullDown()
{
return true;
}
@Override
public boolean canPullUp()
{
return true;
}
}
TextView
public class PullableTextView extends TextView implements Pullable {
public PullableTextView(Context context) {
super(context);
}
public PullableTextView(Context context, AttributeSet attrs) {
super(context, attrs);
}
public PullableTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
}
@Override
public boolean canPullDown() {
return true;
}
@Override
public boolean canPullUp() {
return true;
}
}
4. Use example (taking ListView as an example)
<
android:
android:layout_width="match_parent"
android:layout_height="match_parent">
<include layout="@layout/head" />
<
android:
android:layout_width="match_parent"
android:layout_height="match_parent" />
<include layout="@layout/foot" />
</>
head
<?xml version="1.0" encoding="UTF-8"?>
<RelativeLayout xmlns:andro
android:
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/darker_gray">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:paddingBottom="20dp"
android:paddingTop="20dp">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerInParent="true">
<ImageView
android:
android:layout_width="20dp"
android:layout_height="20dp"
android:layout_centerVertical="true"
android:layout_marginLeft="60dp"
android:scaleType="fitXY" />
<TextView
android:
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:textColor="@android:color/white"
android:textSize="16sp" />
</RelativeLayout>
</RelativeLayout>
</RelativeLayout>
foot
<?xml version="1.0" encoding="UTF-8"?>
<RelativeLayout xmlns:andro
android:
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@android:color/darker_gray">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentTop="true"
android:paddingBottom="20dp"
android:paddingTop="20dp">
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_centerInParent="true">
<ImageView
android:
android:layout_width="20dp"
android:layout_height="20dp"
android:layout_centerVertical="true"
android:layout_marginLeft="60dp"
android:scaleType="fitXY" />
<TextView
android:
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerInParent="true"
android:textColor="@android:color/white"
android:textSize="16sp" />
</RelativeLayout>
</RelativeLayout>
</RelativeLayout>
4. Pay attention
There is no difference between custom View and normal View usage
To implement refresh loading, you must make (onRefreshListener);
The above is all the content of this article. I hope it will be helpful to everyone's study and I hope everyone will support me more.