/**
* 根据当前ListView的滚动状态来设定 {@link #ableToPull}
* 的值，每次都需要在onTouch中第一个执行，这样可以判断出当前应该是滚动ListView，还是应该进行下拉。
*
* @param event
*/
private void setIsAbleToPull(View view, MotionEvent event) {
boolean oldVal = this.ableToPull;
this.ableToPull = this.pullableView.isPullable(view, event);
if (this.ableToPull) {
if (oldVal == false) {
yDown = event.getRawY();
}
} else if (headerLayoutParams.topMargin != hideHeaderHeight) {
headerLayoutParams.topMargin = hideHeaderHeight;
header.setLayoutParams(headerLayoutParams);
}
if (pullableView.getView() instanceof ListView) {
View firstChild = ((ListView) pullableView.getView()).getChildAt(0);
if (firstChild != null) {
int firstVisiblePos = ((ListView) pullableView.getView()).getFirstVisiblePosition();
if (firstVisiblePos == 0 && firstChild.getTop() == 0) {
if (!ableToPull) {
yDown = event.getRawY();
}
// 如果首个元素的上边缘，距离父布局值为0，就说明ListView滚动到了最顶部，此时应该允许下拉刷新
ableToPull = true;
} else {
if (headerLayoutParams.topMargin != hideHeaderHeight) {
headerLayoutParams.topMargin = hideHeaderHeight;
header.setLayoutParams(headerLayoutParams);
}
ableToPull = false;
}
} else {
// 如果ListView中没有元素，也应该允许下拉刷新
ableToPull = true;
}
}
}
protected void updateMargins() {
//noinspection ConstantConditions
final int margin = getResources().getDimensionPixelSize(R.dimen.space_normal);
final boolean titleVisible = title_TV.getVisibility() == VISIBLE;
final boolean secondaryTitleVisible = secondaryTitle_TV.getVisibility() == VISIBLE;
final boolean subTitleVisible = subTitle_TV.getVisibility() == VISIBLE;
final boolean contentVisible = content_FL.getVisibility() == VISIBLE;
final boolean iconVisible = icon_IV.getVisibility() == VISIBLE;
MarginLayoutParams lp = (MarginLayoutParams) subTitle_TV.getLayoutParams();
//noinspection ConstantConditions
lp.topMargin = titleVisible || secondaryTitleVisible ? margin : 0;
lp = (MarginLayoutParams) content_FL.getLayoutParams();
//noinspection ConstantConditions
lp.topMargin = titleVisible || secondaryTitleVisible || subTitleVisible ? margin : 0;
lp = (MarginLayoutParams) icon_IV.getLayoutParams();
//noinspection ConstantConditions
lp.topMargin = titleVisible || secondaryTitleVisible || subTitleVisible ? margin : 0;
lp = (MarginLayoutParams) listContainer_LL.getLayoutParams();
//noinspection ConstantConditions
lp.topMargin =
titleVisible || secondaryTitleVisible || subTitleVisible || contentVisible || iconVisible
? margin
: 0;
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
if (log.isDebugEnabled()) {
log.debug("onLayout ...");
}
super.onLayout(changed, l, t, r, b);
if (changed && (headerLayoutParams == null)) {
hideHeaderHeight = -header.getHeight();
if (log.isDebugEnabled()) {
log.debug("init Layout params, hideHeaderHeight :" + hideHeaderHeight);
}
headerLayoutParams = (MarginLayoutParams) header.getLayoutParams();
headerLayoutParams.topMargin = hideHeaderHeight;
if (!this.pendingTasks.isEmpty()) {
for (AsyncTask<Void, Integer, Integer> task : this.pendingTasks) {
task.execute();
}
this.pendingTasks.clear();
}
} else {
if (log.isDebugEnabled()) {
log.debug("onLayout, hideHeaderHeight :" + headerLayoutParams.topMargin);
}
// header.setLayoutParams(headerLayoutParams);
}
}
/** 当ListView被触摸时调用，其中处理了各种下拉刷新的具体逻辑。 */
@Override
public boolean onTouch(View v, MotionEvent event) {
setIsAbleToPull(event);
if (ableToPull) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
yDown = event.getRawY();
break;
case MotionEvent.ACTION_MOVE:
float yMove = event.getRawY();
int distance = (int) (yMove - yDown);
// 如果手指是下滑状态，并且下拉头是完全隐藏的，就屏蔽下拉事件
if (distance <= 0 && headerLayoutParams.topMargin <= hideHeaderHeight) {
return false;
}
if (distance < touchSlop) {
return false;
}
if (currentStatus != STATUS_REFRESHING) {
if (headerLayoutParams.topMargin > 0) {
currentStatus = STATUS_RELEASE_TO_REFRESH;
} else {
currentStatus = STATUS_PULL_TO_REFRESH;
}
// 通过偏移下拉头的topMargin值，来实现下拉效果
headerLayoutParams.topMargin = (distance / 2) + hideHeaderHeight;
header.setLayoutParams(headerLayoutParams);
}
break;
case MotionEvent.ACTION_UP:
default:
if (currentStatus == STATUS_RELEASE_TO_REFRESH) {
// 松手时如果是释放立即刷新状态，就去调用正在刷新的任务
new RefreshingTask().execute();
} else if (currentStatus == STATUS_PULL_TO_REFRESH) {
// 松手时如果是下拉状态，就去调用隐藏下拉头的任务
new HideHeaderTask().execute();
}
break;
}
// 时刻记得更新下拉头中的信息
if (currentStatus == STATUS_PULL_TO_REFRESH || currentStatus == STATUS_RELEASE_TO_REFRESH) {
updateHeaderView();
// 当前正处于下拉或释放状态，要让ListView失去焦点，否则被点击的那一项会一直处于选中状态
listView.setPressed(false);
listView.setFocusable(false);
listView.setFocusableInTouchMode(false);
lastStatus = currentStatus;
// 当前正处于下拉或释放状态，通过返回true屏蔽掉ListView的滚动事件
return true;
}
}
return false;
}
/** 进行一些关键性的初始化操作，比如：将下拉头向上偏移进行隐藏，给ListView注册touch事件。 */
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
super.onLayout(changed, l, t, r, b);
if (changed && !loadOnce) {
hideHeaderHeight = -header.getHeight();
headerLayoutParams = (MarginLayoutParams) header.getLayoutParams();
headerLayoutParams.topMargin = hideHeaderHeight;
listView = (ListView) getChildAt(1);
listView.setOnTouchListener(this);
loadOnce = true;
}
}
// Wrapper around setting the header offset in different ways depending on
// the API version
@SuppressLint("NewApi")
private void setHeaderOffet(int offset) {
if (mHeaderOffset == null || mHeaderOffset != offset) {
mHeaderOffset = offset;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
mHeader.setTranslationY(mHeaderOffset);
} else {
MarginLayoutParams params = (MarginLayoutParams) mHeader.getLayoutParams();
params.topMargin = mHeaderOffset;
mHeader.setLayoutParams(params);
}
}
}
/** 设置未读消息偏移,原点为文字的右上角.当控件高度固定,消息提示位置易控制,显示效果佳 */
public void setMsgMargin(int position, float leftPadding, float bottomPadding) {
if (position >= mTabCount) {
position = mTabCount - 1;
}
View tabView = mTabsContainer.getChildAt(position);
MsgView tipView = (MsgView) tabView.findViewById(R.id.rtv_msg_tip);
if (tipView != null) {
TextView tv_tab_title = (TextView) tabView.findViewById(R.id.tv_tab_title);
mTextPaint.setTextSize(mTextsize);
float textWidth = mTextPaint.measureText(tv_tab_title.getText().toString());
float textHeight = mTextPaint.descent() - mTextPaint.ascent();
MarginLayoutParams lp = (MarginLayoutParams) tipView.getLayoutParams();
lp.leftMargin =
mTabWidth >= 0
? (int) (mTabWidth / 2 + textWidth / 2 + dp2px(leftPadding))
: (int) (mTabPadding + textWidth + dp2px(leftPadding));
lp.topMargin = mHeight > 0 ? (int) (mHeight - textHeight) / 2 - dp2px(bottomPadding) : 0;
tipView.setLayoutParams(lp);
}
}
/**
* 根据当前ListView的滚动状态来设定 {@link #ableToPull}
* 的值，每次都需要在onTouch中第一个执行，这样可以判断出当前应该是滚动ListView，还是应该进行下拉。
*
* @param event
*/
private void setIsAbleToPull(MotionEvent event) {
View firstChild = listView.getChildAt(0);
if (firstChild != null) {
int firstVisiblePos = listView.getFirstVisiblePosition();
if (firstVisiblePos == 0 && firstChild.getTop() == 0) {
if (!ableToPull) {
yDown = event.getRawY();
}
// 如果首个元素的上边缘，距离父布局值为0，就说明ListView滚动到了最顶部，此时应该允许下拉刷新
ableToPull = true;
} else {
if (headerLayoutParams.topMargin != hideHeaderHeight) {
headerLayoutParams.topMargin = hideHeaderHeight;
header.setLayoutParams(headerLayoutParams);
}
ableToPull = false;
}
} else {
// 如果ListView中没有元素，也应该允许下拉刷新
ableToPull = true;
}
}
private void applyMarginInsets(
MarginLayoutParams lp, Object insets, int drawerGravity, boolean topOnly) {
WindowInsets wi = (WindowInsets) insets;
if (drawerGravity == Gravity.LEFT) {
wi =
wi.replaceSystemWindowInsets(
wi.getSystemWindowInsetLeft(),
wi.getSystemWindowInsetTop(),
0,
wi.getSystemWindowInsetBottom());
} else if (drawerGravity == Gravity.RIGHT) {
wi =
wi.replaceSystemWindowInsets(
0,
wi.getSystemWindowInsetTop(),
wi.getSystemWindowInsetRight(),
wi.getSystemWindowInsetBottom());
}
lp.leftMargin = wi.getSystemWindowInsetLeft();
lp.topMargin = topOnly ? 0 : wi.getSystemWindowInsetTop();
lp.rightMargin = wi.getSystemWindowInsetRight();
lp.bottomMargin = wi.getSystemWindowInsetBottom();
}
/** 当ListView被触摸时调用，其中处理了各种下拉刷新的具体逻辑。 */
@Override
public boolean onTouch(View v, MotionEvent event) {
setIsAbleToPull(v, event);
boolean retVal = false;
if (ableToPull) {
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
yDown = event.getRawY();
// if(log.isDebugEnabled()){
// log.debug("Touch down, y position :"+yDown);
// }
break;
case MotionEvent.ACTION_MOVE:
float yMove = event.getRawY();
int distance = (int) (yMove - yDown);
// if(log.isDebugEnabled()){
// log.debug("Touch down and move, y position :"+yMove+", move distance :"+distance);
// }
// 如果手指是下滑状态，并且下拉头是完全隐藏的，就屏蔽下拉事件
if (distance <= 0 && headerLayoutParams.topMargin <= hideHeaderHeight) {
return false;
}
if (distance < touchSlop) {
return false;
}
if (!pullStarted) {
// if(log.isDebugEnabled()){
// log.debug("Pull started, touchSlop = "+touchSlop);
// }
pullableView.pullStarted(v);
pullStarted = true;
}
retVal = true;
if (currentStatus != STATUS_REFRESHING) {
if (headerLayoutParams.topMargin > 0) {
currentStatus = STATUS_RELEASE_TO_REFRESH;
} else {
currentStatus = STATUS_PULL_TO_REFRESH;
}
// 通过偏移下拉头的topMargin值，来实现下拉效果
headerLayoutParams.topMargin = (distance / 2) + hideHeaderHeight;
header.setLayoutParams(headerLayoutParams);
}
break;
case MotionEvent.ACTION_UP:
default:
if (pullStarted) {
pullableView.pullEnded(v);
pullStarted = false;
retVal = true;
}
if (currentStatus == STATUS_RELEASE_TO_REFRESH) {
// 松手时如果是释放立即刷新状态，就去调用正在刷新的任务
setOnRefreshing(true);
} else if (currentStatus == STATUS_PULL_TO_REFRESH) {
// 松手时如果是下拉状态，就去调用隐藏下拉头的任务
hideHeader();
}
break;
}
// 时刻记得更新下拉头中的信息
if (currentStatus == STATUS_PULL_TO_REFRESH || currentStatus == STATUS_RELEASE_TO_REFRESH) {
updateHeaderView();
// 当前正处于下拉或释放状态，要让ListView失去焦点，否则被点击的那一项会一直处于选中状态
pullableView.getView().setPressed(false);
pullableView.getView().setFocusable(false);
pullableView.getView().setFocusableInTouchMode(false);
lastStatus = currentStatus;
// 当前正处于下拉或释放状态，通过返回true屏蔽掉ListView的滚动事件
}
}
return retVal;
}
private void setMargin(int top) {
headerMargins.topMargin = top;
LayoutParams params = new LayoutParams(headerMargins);
header.setLayoutParams(params);
}
package com.chang.news.util;