package cn.jmessage.android.uikit.chatting;
/**
* DropDownListView
*
* @author Trinea 2013-6-1
*/
import android.content.Context;
import android.content.res.TypedArray;
import android.util.AttributeSet;
import android.view.LayoutInflater;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AbsListView;
import android.widget.AbsListView.OnScrollListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.RelativeLayout;
import cn.jmessage.android.uikit.chatting.utils.IdHelper;
public class DropDownListView extends ListView implements OnScrollListener {
private boolean isDropDownStyle = true;
private Context context;
private static final int PAGE_MESSAGE_COUNT = 18;
/**
* header layout view
**/
private RelativeLayout headerLayout;
private ProgressBar headerProgressBar;
private OnDropDownListener onDropDownListener;
private OnScrollListener onScrollListener;
/**
* min distance which header can release to loading
**/
private int currentScrollState;
private int currentHeaderStatus;
/**
* whether reached top, when has reached top, don't show header layout
**/
private boolean hasReachedTop = false;
/**
* header layout original height
**/
private int headerOriginalHeight;
/**
* header layout original padding top
**/
private int headerOriginalTopPadding;
/**
* y of point which user touch down
**/
private float actionDownPointY;
private float actionMovePointY;
private int mOffset = PAGE_MESSAGE_COUNT;
public DropDownListView(Context context) {
super(context);
init(context);
}
public DropDownListView(Context context, AttributeSet attrs) {
super(context, attrs);
getAttrs(context, attrs);
init(context);
}
public DropDownListView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
getAttrs(context, attrs);
init(context);
}
private void init(Context context) {
this.context = context;
initDropDownStyle();
// should set, to run onScroll method and so on
super.setOnScrollListener(this);
}
/**
* init drop down style, only init once
*/
private void initDropDownStyle() {
if (headerLayout != null) {
if (isDropDownStyle) {
addHeaderView(headerLayout);
} else {
removeHeaderView(headerLayout);
}
return;
}
if (!isDropDownStyle) {
return;
}
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
headerLayout = (RelativeLayout) inflater.inflate(IdHelper.getLayout(context, "jmui_drop_down_list_header"),
this, false);
headerProgressBar = (ProgressBar) headerLayout.findViewById(IdHelper.getViewID(context,
"jmui_drop_down_list_header_progress_bar"));
addHeaderView(headerLayout);
measureHeaderLayout(headerLayout);
headerOriginalHeight = headerLayout.getMeasuredHeight();
headerOriginalTopPadding = headerLayout.getPaddingTop();
currentHeaderStatus = HEADER_STATUS_CLICK_TO_LOAD;
}
@Override
public void setAdapter(ListAdapter adapter) {
super.setAdapter(adapter);
if (isDropDownStyle) {
setSecondPositionVisible();
}
}
@Override
public void setOnScrollListener(OnScrollListener listener) {
onScrollListener = listener;
}
/**
* @param onDropDownListener
*/
public void setOnDropDownListener(OnDropDownListener onDropDownListener) {
this.onDropDownListener = onDropDownListener;
}
@Override
public boolean onTouchEvent(MotionEvent event) {
if (!isDropDownStyle) {
return super.onTouchEvent(event);
}
hasReachedTop = false;
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
actionDownPointY = event.getY();
break;
case MotionEvent.ACTION_MOVE:
actionMovePointY = event.getY();
break;
case MotionEvent.ACTION_UP:
if (!isVerticalScrollBarEnabled()) {
setVerticalScrollBarEnabled(true);
}
if (getFirstVisiblePosition() == 0 && currentHeaderStatus != HEADER_STATUS_LOADING) {
switch (currentHeaderStatus) {
case HEADER_STATUS_RELEASE_TO_LOAD:
onDropDown();
break;
case HEADER_STATUS_DROP_DOWN_TO_LOAD:
break;
case HEADER_STATUS_CLICK_TO_LOAD:
default:
break;
}
}
break;
}
return super.onTouchEvent(event);
}
@Override
public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) {
if (isDropDownStyle) {
if (currentScrollState == SCROLL_STATE_TOUCH_SCROLL && currentHeaderStatus != HEADER_STATUS_LOADING) {
if (firstVisibleItem == 0 && actionMovePointY - actionDownPointY > 0
&& mOffset == PAGE_MESSAGE_COUNT) {
onDropDown();
}
} else if (currentScrollState == SCROLL_STATE_FLING && firstVisibleItem == 0
&& currentHeaderStatus != HEADER_STATUS_LOADING) {
/**
* when state of ListView is SCROLL_STATE_FLING(ListView is scrolling but finger has leave screen) and
* first item(header layout) is visible and header status is not HEADER_STATUS_LOADING, then hide first
* item, set second item visible and set hasReachedTop true.
*/
if (mOffset == PAGE_MESSAGE_COUNT){
onDropDown();
}
hasReachedTop = true;
} else if (currentScrollState == SCROLL_STATE_FLING && hasReachedTop) {
setSelection(0);
}
}
if (onScrollListener != null) {
onScrollListener.onScroll(view, firstVisibleItem, visibleItemCount, totalItemCount);
}
}
@Override
public void onScrollStateChanged(AbsListView view, int scrollState) {
if (isDropDownStyle) {
currentScrollState = scrollState;
if (currentScrollState == SCROLL_STATE_IDLE) {
hasReachedTop = false;
}
}
if (onScrollListener != null) {
onScrollListener.onScrollStateChanged(view, scrollState);
}
}
/**
* drop down begin, adjust view status
*/
private void onDropDownBegin() {
if (isDropDownStyle) {
setHeaderStatusLoading();
}
}
/**
* on drop down loading, you can call it by manual, but you should manual call onBottomComplete at the same time.
*/
public void onDropDown() {
if (currentHeaderStatus != HEADER_STATUS_LOADING && isDropDownStyle && onDropDownListener != null) {
onDropDownBegin();
onDropDownListener.onDropDown();
}
}
/**
* drop down complete, restore view status
*
* @param secondText display below header text, if null, not display
*/
public void onDropDownComplete(CharSequence secondText) {
if (isDropDownStyle) {
onDropDownComplete();
}
}
/**
* drop down complete, restore view status
*/
public void onDropDownComplete() {
if (isDropDownStyle) {
resetHeader();
if (headerLayout.getBottom() > 0) {
invalidateViews();
}
}
}
private void resetHeader() {
if (currentHeaderStatus != HEADER_STATUS_CLICK_TO_LOAD) {
resetHeaderPadding();
headerProgressBar.setVisibility(View.GONE);
currentHeaderStatus = HEADER_STATUS_DROP_DOWN_TO_LOAD;
}
}
/**
* OnDropDownListener, called when header released
*/
public interface OnDropDownListener {
/**
* called when header released
*/
public void onDropDown();
}
/**
* set second position visible(index is 1), because first position is header layout
*/
public void setSecondPositionVisible() {
if (getAdapter() != null && getAdapter().getCount() > 0 && getFirstVisiblePosition() == 0) {
setSelection(1);
}
}
public void setOffset(int offset){
mOffset = offset;
}
/**
* status which you can click to load, init satus
**/
public static final int HEADER_STATUS_CLICK_TO_LOAD = 1;
/**
* status which you can drop down and then release to excute onDropDownListener, when height of header layout lower
* than a value
**/
public static final int HEADER_STATUS_DROP_DOWN_TO_LOAD = 2;
/**
* status which you can release to excute onDropDownListener, when height of header layout higher than a value
**/
public static final int HEADER_STATUS_RELEASE_TO_LOAD = 3;
/**
* status which is loading
**/
public static final int HEADER_STATUS_LOADING = 4;
/**
* set header status to {@link #HEADER_STATUS_LOADING}
*/
private void setHeaderStatusLoading() {
if (currentHeaderStatus != HEADER_STATUS_LOADING) {
resetHeaderPadding();
headerProgressBar.setVisibility(View.VISIBLE);
currentHeaderStatus = HEADER_STATUS_LOADING;
setSelection(0);
}
}
/**
* reset header padding
*/
private void resetHeaderPadding() {
headerLayout.setPadding(headerLayout.getPaddingLeft(), headerOriginalTopPadding,
headerLayout.getPaddingRight(), headerLayout.getPaddingBottom());
}
/**
* measure header layout
*
* @param child
*/
private void measureHeaderLayout(View child) {
ViewGroup.LayoutParams p = child.getLayoutParams();
if (p == null) {
p = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.WRAP_CONTENT);
}
int childWidthSpec = ViewGroup.getChildMeasureSpec(0, 0, p.width);
int lpHeight = p.height;
int childHeightSpec;
if (lpHeight > 0) {
childHeightSpec = MeasureSpec.makeMeasureSpec(lpHeight, MeasureSpec.EXACTLY);
} else {
childHeightSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
}
child.measure(childWidthSpec, childHeightSpec);
}
/**
* get attrs
*
* @param context
* @param attrs
*/
private void getAttrs(Context context, AttributeSet attrs) {
int[] dropDownAttrArray = IdHelper.getResourceDeclareStyleableIntArray(context, "drop_down_list_attr");
if (dropDownAttrArray != null) {
TypedArray ta = context.obtainStyledAttributes(attrs, dropDownAttrArray);
isDropDownStyle = ta.getBoolean(1, true);
ta.recycle();
}
}
public int getHeaderHeight() {
return headerOriginalHeight;
}
}
