先看效果:
主要处理:
使用PullToRefreshScrollView修改内部的scrollView源码,更换成可以固定顶部的自定义scrollView
@Override
protected ScrollView createRefreshableView(Context context, AttributeSet attrs) {
ScrollView scrollView;
if (VERSION.SDK_INT >= VERSION_CODES.GINGERBREAD) {
//TODO 修改代码 添加滑动固定顶部标题sv
scrollView = new InternalScrollViewSDK9(context, attrs);
// scrollView = new FloatScrollView(context, attrs);
} else {
scrollView = new ScrollView(context, attrs);
}
scrollView.setId(R.id.scrollview);
return scrollView;
}
下面是scrollview的代码:
public static final String FLOAT = "float";
private ArrayList<View> stickyViews;
private View currentlyStickingView;
private float stickyViewTopOffset;
private int stickyViewLeftOffset;
private boolean redirectTouchesToStickyView;
private boolean clippingToPadding;
private boolean clipToPaddingHasBeenSet;
private final Runnable invalidateRunnable = new Runnable() {
@Override
public void run() {
if (currentlyStickingView != null) {
int l = getLeftForViewRelativeOnlyChild(currentlyStickingView);
int t = getBottomForViewRelativeOnlyChild(currentlyStickingView);
int r = getRightForViewRelativeOnlyChild(currentlyStickingView);
int b = (int) (getScrollY() + (currentlyStickingView.getHeight() + stickyViewTopOffset));
invalidate(l, t, r, b);
}
postDelayed(this, 16);
}
};
public void setup() {
stickyViews = new ArrayList<View>();
}
private int getLeftForViewRelativeOnlyChild(View v) {
int left = v.getLeft();
while (v.getParent() != getChildAt(0)) {
v = (View) v.getParent();
left += v.getLeft();
}
return left;
}
private int getTopForViewRelativeOnlyChild(View v) {
int top = v.getTop();
while (v.getParent() != getChildAt(0)) {
v = (View) v.getParent();
top += v.getTop();
}
return top;
}
private int getRightForViewRelativeOnlyChild(View v) {
int right = v.getRight();
while (v.getParent() != getChildAt(0)) {
v = (View) v.getParent();
right += v.getRight();
}
return right;
}
private int getBottomForViewRelativeOnlyChild(View v) {
int bottom = v.getBottom();
while (v.getParent() != getChildAt(0)) {
v = (View) v.getParent();
bottom += v.getBottom();
}
return bottom;
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
super.onLayout(changed, l, t, r, b);
if (!clipToPaddingHasBeenSet) {
clippingToPadding = true;
}
notifyHierarchyChanged();
}
@Override
public void setClipToPadding(boolean clipToPadding) {
super.setClipToPadding(clipToPadding);
clippingToPadding = clipToPadding;
clipToPaddingHasBeenSet = true;
}
@Override
public void addView(View child) {
super.addView(child);
findStickyViews(child);
}
@Override
public void addView(View child, int index) {
super.addView(child, index);
findStickyViews(child);
}
@Override
public void addView(View child, int index, android.view.ViewGroup.LayoutParams params) {
super.addView(child, index, params);
findStickyViews(child);
}
@Override
public void addView(View child, int width, int height) {
super.addView(child, width, height);
findStickyViews(child);
}
@Override
public void addView(View child, android.view.ViewGroup.LayoutParams params) {
super.addView(child, params);
findStickyViews(child);
}
@Override
protected void dispatchDraw(Canvas canvas) {
super.dispatchDraw(canvas);
if (currentlyStickingView != null) {
canvas.save();
canvas.translate(getPaddingLeft() + stickyViewLeftOffset, getScrollY() + stickyViewTopOffset + (clippingToPadding ? getPaddingTop() : 0));
canvas.clipRect(0, (clippingToPadding ? -stickyViewTopOffset : 0), getWidth(), currentlyStickingView.getHeight());
currentlyStickingView.draw(canvas);
canvas.restore();
}
}
@Override
public boolean dispatchTouchEvent(MotionEvent ev) {
if (ev.getAction() == MotionEvent.ACTION_DOWN) {
redirectTouchesToStickyView = true;
}
if (redirectTouchesToStickyView) {
redirectTouchesToStickyView = currentlyStickingView != null;
if (redirectTouchesToStickyView) {
redirectTouchesToStickyView =
ev.getY() <= (currentlyStickingView.getHeight() + stickyViewTopOffset) &&
ev.getX() >= getLeftForViewRelativeOnlyChild(currentlyStickingView) &&
ev.getX() <= getRightForViewRelativeOnlyChild(currentlyStickingView);
}
} else if (currentlyStickingView == null) {
redirectTouchesToStickyView = false;
}
if (redirectTouchesToStickyView) {
topForViewRelativeOnlyChild = getTopForViewRelativeOnlyChild(currentlyStickingView);
ev.offsetLocation(0, -1 * ((getScrollY() + stickyViewTopOffset) - topForViewRelativeOnlyChild));
}
return super.dispatchTouchEvent(ev);
}
private boolean hasNotDoneActionDown = true;
@Override
public boolean onTouchEvent(MotionEvent ev) {
if (redirectTouchesToStickyView) {
ev.offsetLocation(0, ((getScrollY() + stickyViewTopOffset) - getTopForViewRelativeOnlyChild(currentlyStickingView)));
}
if (ev.getAction() == MotionEvent.ACTION_DOWN || ev.getAction() == MotionEvent.ACTION_MOVE) {
hasNotDoneActionDown = false;
}
if (hasNotDoneActionDown) {
MotionEvent down = MotionEvent.obtain(ev);
down.setAction(MotionEvent.ACTION_DOWN);
super.onTouchEvent(down);
hasNotDoneActionDown = false;
}
if (ev.getAction() == MotionEvent.ACTION_UP || ev.getAction() == MotionEvent.ACTION_CANCEL) {
hasNotDoneActionDown = true;
}
return super.onTouchEvent(ev);
}
@Override
protected void onScrollChanged(int l, int t, int oldl, int oldt) {
super.onScrollChanged(l, t, oldl, oldt);
doTheStickyThing();
}
private void doTheStickyThing() {
View viewThatShouldStick = null;
View approachingView = null;
for (View v : stickyViews) {
int viewTop = getTopForViewRelativeOnlyChild(v) - getScrollY() + (clippingToPadding ? 0 : getPaddingTop());
if (viewTop <= 0) {
if (viewThatShouldStick == null || viewTop > (getTopForViewRelativeOnlyChild(viewThatShouldStick) - getScrollY() + (clippingToPadding ? 0 : getPaddingTop()))) {
viewThatShouldStick = v;
}
} else {
if (approachingView == null || viewTop < (getTopForViewRelativeOnlyChild(approachingView) - getScrollY() + (clippingToPadding ? 0 : getPaddingTop()))) {
approachingView = v;
}
}
}
if (viewThatShouldStick != null) {
stickyViewTopOffset = approachingView == null ? 0 : Math.min(0, getTopForViewRelativeOnlyChild(approachingView) - getScrollY() + (clippingToPadding ? 0 : getPaddingTop()) - viewThatShouldStick.getHeight());
if (viewThatShouldStick != currentlyStickingView) {
if (currentlyStickingView != null) {
stopStickingCurrentlyStickingView();
}
stickyViewLeftOffset = getLeftForViewRelativeOnlyChild(viewThatShouldStick);
startStickingView(viewThatShouldStick);
}
} else if (currentlyStickingView != null) {
stopStickingCurrentlyStickingView();
}
}
private void startStickingView(View viewThatShouldStick) {
currentlyStickingView = viewThatShouldStick;
}
private void stopStickingCurrentlyStickingView() {
currentlyStickingView = null;
removeCallbacks(invalidateRunnable);
}
private void notifyHierarchyChanged() {
if (currentlyStickingView != null) {
stopStickingCurrentlyStickingView();
}
stickyViews.clear();
findStickyViews(getChildAt(0));
doTheStickyThing();
invalidate();
}
private void findStickyViews(View v) {
if (v instanceof ViewGroup) {
ViewGroup vg = (ViewGroup) v;
for (int i = 0; i < vg.getChildCount(); i++) {
String tag = getStringTagForView(vg.getChildAt(i));
if (tag != null && tag.contains(FLOAT)) {
stickyViews.add(vg.getChildAt(i));
} else if (vg.getChildAt(i) instanceof ViewGroup) {
findStickyViews(vg.getChildAt(i));
}
}
} else {
String tag = (String) v.getTag();
if (tag != null && tag.contains(FLOAT)) {
stickyViews.add(v);
}
}
}
private String getStringTagForView(View v) {
Object tagObject = v.getTag();
return String.valueOf(tagObject);
}
}