package com.gzgd.myapplication4;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.os.Build;
import android.os.Bundle;
import android.os.Parcel;
import android.os.Parcelable;
import android.util.AttributeSet;
import android.util.Log;
import android.view.FocusFinder;
import android.view.KeyEvent;
import android.view.MotionEvent;
import android.view.VelocityTracker;
import android.view.View;
import android.view.ViewConfiguration;
import android.view.ViewDebug;
import android.view.ViewGroup;
import android.view.ViewParent;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityNodeInfo;
import android.view.animation.AnimationUtils;
import android.widget.EdgeEffect;
import android.widget.FrameLayout;
import android.widget.OverScroller;
import android.widget.ScrollView;
import java.util.List;
/**
*翻页有反弹效果
- Created by runrun on 2018/4/4.
*/
public class MScrollView extends FrameLayout {
static final int ANIMATED_SCROLL_GAP = 200;
static final float MAX_SCROLL_FACTOR = 0.5f;
private static final String TAG = "MScrollView";
private long mLastScroll;
protected final Rect mTempRect = new Rect();
private OverScroller mScroller;
private EdgeEffect mEdgeGlowTop;
private EdgeEffect mEdgeGlowBottom;
/**
* True when the layout has changed but the traversal has not come through yet.
* Ideally the view hierarchy would keep track of this for us.
*/
private boolean mIsLayoutDirty = true;
/**
* The child to give focus to in the event that a child has requested focus while the
* layout is dirty. This prevents the scroll from being wrong if the child has not been
* laid out before requesting focus.
*/
private View mChildToScrollTo = null;
/**
* Determines speed during touch scrolling
*/
private VelocityTracker mVelocityTracker;
/**
* When set to true, the scroll view measure its child to make it fill the currently
* visible area.
*/
@ViewDebug.ExportedProperty(category = "layout")
private boolean mFillViewport;
/**
* Whether arrow scrolling is animated.
*/
private boolean mSmoothScrollingEnabled = true;
private int mOverflingDistance;
/**
* ID of the active pointer. This is used to retain consistency during
* drags/flings if multiple pointers are used.
*/
private int mActivePointerId = INVALID_POINTER;
/**
* Sentinel value for no current active pointer.
* Used by {@link #mActivePointerId}.
*/
private static final int INVALID_POINTER = -1;
private MScrollView.SavedState mSavedState;
private Context mContext;
public MScrollView(Context context) {
this(context, null);
}
public MScrollView(Context context, AttributeSet attrs) {
this(context, attrs, com.android.internal.R.attr.scrollViewStyle);
}
public MScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
this(context, attrs, defStyleAttr, 0);
}
public MScrollView(Context context, AttributeSet attrs, int defStyleAttr, int defStyleRes) {
super(context, attrs, defStyleAttr, defStyleRes);
mContext = context;
initScrollView();
final TypedArray a = context.obtainStyledAttributes(
attrs, com.android.internal.R.styleable.ScrollView, defStyleAttr, defStyleRes);
setFillViewport(a.getBoolean(com.android.internal.R.styleable.ScrollView_fillViewport, false));
a.recycle();
}
@Override
public boolean shouldDelayChildPressedState() {
return true;
}
@Override
protected float getTopFadingEdgeStrength() {
if (getChildCount() == 0) {
return 0.0f;
}
final int length = getVerticalFadingEdgeLength();
if (getScrollY() < length) {
return getScrollY() / (float) length;
}
return 1.0f;
}
@Override
protected float getBottomFadingEdgeStrength() {
if (getChildCount() == 0) {
return 0.0f;
}
final int length = getVerticalFadingEdgeLength();
final int bottomEdge = getHeight() - getPaddingBottom();
final int span = getChildAt(0).getBottom() - getScrollY() - bottomEdge;
if (span < length) {
return span / (float) length;
}
return 1.0f;
}
/**
* @return The maximum amount this scroll view will scroll in response to
* an arrow event.
*/
public int getMaxScrollAmount() {
return (int) (MAX_SCROLL_FACTOR * (getBottom() - getTop()));
}
private void initScrollView() {
mScroller = new OverScroller(getContext());
setFocusable(true);
setDescendantFocusability(FOCUS_AFTER_DESCENDANTS);
setWillNotDraw(false);
final ViewConfiguration configuration = ViewConfiguration.get(mContext);
mOverflingDistance = configuration.getScaledOverflingDistance();
}
@Override
public void addView(View child) {
if (getChildCount() > 0) {
throw new IllegalStateException("ScrollView can host only one direct child");
}
super.addView(child);
}
@Override
public void addView(View child, int index) {
if (getChildCount() > 0) {
throw new IllegalStateException("ScrollView can host only one direct child");
}
super.addView(child, index);
}
@Override
public void addView(View child, ViewGroup.LayoutParams params) {
if (getChildCount() > 0) {
throw new IllegalStateException("ScrollView can host only one direct child");
}
super.addView(child, params);
}
@Override
public void addView(View child, int index, ViewGroup.LayoutParams params) {
if (getChildCount() > 0) {
throw new IllegalStateException("ScrollView can host only one direct child");
}
super.addView(child, index, params);
}
/**
* @return Returns true this ScrollView can be scrolled
*/
protected boolean canScroll() {
View child = getChildAt(0);
if (child != null) {
int childHeight = child.getHeight();
return getHeight() < childHeight + getPaddingTop() + getPaddingBottom();
}
return false;
}
/**
* Indicates whether this ScrollView's content is stretched to fill the viewport.
*
* @return True if the content fills the viewport, false otherwise.
* @attr ref android.R.styleable#ScrollView_fillViewport
*/
public boolean isFillViewport() {
return mFillViewport;
}
/**
* Indicates this ScrollView whether it should stretch its content height to fill
* the viewport or not.
*
* @param fillViewport True to stretch the content's height to the viewport's
* boundaries, false otherwise.
* @attr ref android.R.styleable#ScrollView_fillViewport
*/
public void setFillViewport(boolean fillViewport) {
if (fillViewport != mFillViewport) {
mFillViewport = fillViewport;
requestLayout();
}
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (!mFillViewport) {
return;
}
final int heightMode = MeasureSpec.getMode(heightMeasureSpec);
if (heightMode == MeasureSpec.UNSPECIFIED) {
return;
}
if (getChildCount() > 0) {
final View child = getChildAt(0);
int height = getMeasuredHeight();
if (child.getMeasuredHeight() < height) {
final FrameLayout.LayoutParams lp = (LayoutParams) child.getLayoutParams();
int childWidthMeasureSpec = getChildMeasureSpec(widthMeasureSpec,
getPaddingLeft() + getPaddingRight(), lp.width);
height -= getPaddingTop();
height -= getPaddingBottom();
int childHeightMeasureSpec =
MeasureSpec.makeMeasureSpec(height, MeasureSpec.EXACTLY);
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
}
}
@Override
public boolean dispatchKeyEvent(KeyEvent event) {
// Let the focused view and/or our descendants get the key first
boolean isdis = super.dispatchKeyEvent(event);
Log.i(TAG, "---------- dispatchKeyEvent : " + isdis);
return isdis || executeKeyEvent(event);
}
/**
* You can call this function yourself to have the scroll view perform
* scrolling from a key event, just as if the event had been dispatched to
* it by the view hierarchy.
*
* @param event The key event to execute.
* @return Return true if the event was handled, else false.
*/
public boolean executeKeyEvent(KeyEvent event) {
mTempRect.setEmpty();
if (!canScroll()) {
if (isFocused() && event.getKeyCode() != KeyEvent.KEYCODE_BACK) {
View currentFocused = findFocus();
if (currentFocused == this) currentFocused = null;
View nextFocused = FocusFinder.getInstance().findNextFocus(this,
currentFocused, View.FOCUS_DOWN);
return nextFocused != null
&& nextFocused != this
&& nextFocused.requestFocus(View.FOCUS_DOWN);
}
return false;
}
boolean handled = false;
if (event.getAction() == KeyEvent.ACTION_DOWN) {
switch (event.getKeyCode()) {
case KeyEvent.KEYCODE_DPAD_UP:
if (!event.isAltPressed()) {
handled = arrowScroll(View.FOCUS_UP);
} else {
handled = fullScroll(View.FOCUS_UP);
}
break;
case KeyEvent.KEYCODE_DPAD_DOWN:
if (!event.isAltPressed()) {
handled = arrowScroll(View.FOCUS_DOWN);
} else {
handled = fullScroll(View.FOCUS_DOWN);
}
break;
case KeyEvent.KEYCODE_SPACE:
pageScroll(event.isShiftPressed() ? View.FOCUS_UP : View.FOCUS_DOWN);
break;
}
}
return handled;
}
private boolean inChild(int x, int y) {
if (getChildCount() > 0) {
final int scrollY = getScrollY();
final View child = getChildAt(0);
return !(y < child.getTop() - scrollY
|| y >= child.getBottom() - scrollY
|| x < child.getLeft()
|| x >= child.getRight());
}
return false;
}
private void recycleVelocityTracker() {
if (mVelocityTracker != null) {
mVelocityTracker.recycle();
mVelocityTracker = null;
}
}
@Override
public void requestDisallowInterceptTouchEvent(boolean disallowIntercept) {
if (disallowIntercept) {
recycleVelocityTracker();
}
super.requestDisallowInterceptTouchEvent(disallowIntercept);
}
@Override
public boolean onInterceptTouchEvent(MotionEvent ev) {
return true;
}
@Override
public boolean onTouchEvent(MotionEvent ev) {
return true;
}
@Override
public boolean onGenericMotionEvent(MotionEvent event) {
return super.onGenericMotionEvent(event);
}
@Override
protected void onOverScrolled(int scrollX, int scrollY,
boolean clampedX, boolean clampedY) {
// Treat animating scrolls differently; see #computeScroll() for why.
if (!mScroller.isFinished()) {
final int oldX = getScrollX();
final int oldY = getScrollY();
setScrollX(scrollX);
setScrollY(scrollY);
invalidateParentIfNeeded();
onScrollChanged(getScrollX(), getScrollY(), oldX, oldY);
if (clampedY) {
mScroller.springBack(getScrollX(), getScrollY(), 0, 0, 0, getScrollRange());
}
} else {
super.scrollTo(scrollX, scrollY);
}
// awakenScrollBars();
}
protected void invalidateParentIfNeeded() {
if (isHardwareAccelerated() && getParent() instanceof View) {
((View) getParent()).invalidate();
}
}
@Override
public boolean performAccessibilityAction(int action, Bundle arguments) {
if (super.performAccessibilityAction(action, arguments)) {
return true;
}
if (!isEnabled()) {
return false;
}
switch (action) {
case AccessibilityNodeInfo.ACTION_SCROLL_FORWARD: {
final int viewportHeight = getHeight() - getPaddingBottom() - getPaddingTop();
final int targetScrollY = Math.min(getScrollY() + viewportHeight, getScrollRange());
if (targetScrollY != getScrollY()) {
smoothScrollTo(0, targetScrollY);
return true;
}
}
return false;
case AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD: {
final int viewportHeight = getHeight() - getPaddingBottom() - getPaddingTop();
final int targetScrollY = Math.max(getScrollY() - viewportHeight, 0);
if (targetScrollY != getScrollY()) {
smoothScrollTo(0, targetScrollY);
return true;
}
}
return false;
}
return false;
}
@Override
public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo info) {
super.onInitializeAccessibilityNodeInfo(info);
info.setClassName(ScrollView.class.getName());
if (isEnabled()) {
final int scrollRange = getScrollRange();
if (scrollRange > 0) {
info.setScrollable(true);
if (getScrollY() > 0) {
info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_BACKWARD);
}
if (getScrollY() < scrollRange) {
info.addAction(AccessibilityNodeInfo.ACTION_SCROLL_FORWARD);
}
}
}
}
@Override
public void onInitializeAccessibilityEvent(AccessibilityEvent event) {
super.onInitializeAccessibilityEvent(event);
event.setClassName(ScrollView.class.getName());
final boolean scrollable = getScrollRange() > 0;
event.setScrollable(scrollable);
event.setScrollX(getScrollX());
event.setScrollY(getScrollY());
event.setMaxScrollX(getScrollX());
event.setMaxScrollY(getScrollRange());
}
private int getScrollRange() {
int scrollRange = 0;
if (getChildCount() > 0) {
View child = getChildAt(0);
scrollRange = Math.max(0,
child.getHeight() - (getHeight() - getPaddingBottom() - getPaddingTop()));
}
return scrollRange;
}
/**
* <p>
* Finds the next focusable component that fits in the specified bounds.
* </p>
*
* @param topFocus look for a candidate is the one at the top of the bounds
* if topFocus is true, or at the bottom of the bounds if topFocus is
* false
* @param top the top offset of the bounds in which a focusable must be
* found
* @param bottom the bottom offset of the bounds in which a focusable must
* be found
* @return the next focusable component in the bounds or null if none can
* be found
*/
private View findFocusableViewInBounds(boolean topFocus, int top, int bottom) {
List<View> focusables = getFocusables(View.FOCUS_FORWARD);
View focusCandidate = null;
/*
* A fully contained focusable is one where its top is below the bound's
* top, and its bottom is above the bound's bottom. A partially
* contained focusable is one where some part of it is within the
* bounds, but it also has some part that is not within bounds. A fully contained
* focusable is preferred to a partially contained focusable.
*/
boolean foundFullyContainedFocusable = false;
int count = focusables.size();
for (int i = 0; i < count; i++) {
View view = focusables.get(i);
int viewTop = view.getTop();
int viewBottom = view.getBottom();
if (top < viewBottom && viewTop < bottom) {
/*
* the focusable is in the target area, it is a candidate for
* focusing
*/
final boolean viewIsFullyContained = (top < viewTop) &&
(viewBottom < bottom);
if (focusCandidate == null) {
/* No candidate, take this one */
focusCandidate = view;
foundFullyContainedFocusable = viewIsFullyContained;
} else {
final boolean viewIsCloserToBoundary =
(topFocus && viewTop < focusCandidate.getTop()) ||
(!topFocus && viewBottom > focusCandidate
.getBottom());
if (foundFullyContainedFocusable) {
if (viewIsFullyContained && viewIsCloserToBoundary) {
/*
* We're dealing with only fully contained views, so
* it has to be closer to the boundary to beat our
* candidate
*/
focusCandidate = view;
}
} else {
if (viewIsFullyContained) {
/* Any fully contained view beats a partially contained view */
focusCandidate = view;
foundFullyContainedFocusable = true;
} else if (viewIsCloserToBoundary) {
/*
* Partially contained view beats another partially
* contained view if it's closer
*/
focusCandidate = view;
}
}
}
}
}
return focusCandidate;
}
/**
* <p>Handles scrolling in response to a "page up/down" shortcut press. This
* method will scroll the view by one page up or down and give the focus
* to the topmost/bottommost component in the new visible area. If no
* component is a good candidate for focus, this scrollview reclaims the
* focus.</p>
*
* @param direction the scroll direction: {@link android.view.View#FOCUS_UP}
* to go one page up or
* {@link android.view.View#FOCUS_DOWN} to go one page down
* @return true if the key event is consumed by this method, false otherwise
*/
public boolean pageScroll(int direction) {
boolean down = direction == View.FOCUS_DOWN;
int height = getHeight();
if (down) {
mTempRect.top = getScrollY() + height;
int count = getChildCount();
if (count > 0) {
View view = getChildAt(count - 1);
if (mTempRect.top + height > view.getBottom()) {
mTempRect.top = view.getBottom() - height;
}
}
} else {
mTempRect.top = getScrollY() - height;
if (mTempRect.top < 0) {
mTempRect.top = 0;
}
}
mTempRect.bottom = mTempRect.top + height;
return scrollAndFocus(direction, mTempRect.top, mTempRect.bottom);
}
/**
* <p>Handles scrolling in response to a "home/end" shortcut press. This
* method will scroll the view to the top or bottom and give the focus
* to the topmost/bottommost component in the new visible area. If no
* component is a good candidate for focus, this scrollview reclaims the
* focus.</p>
*
* @param direction the scroll direction: {@link android.view.View#FOCUS_UP}
* to go the top of the view or
* {@link android.view.View#FOCUS_DOWN} to go the bottom
* @return true if the key event is consumed by this method, false otherwise
*/
public boolean fullScroll(int direction) {
boolean down = direction == View.FOCUS_DOWN;
int height = getHeight();
mTempRect.top = 0;
mTempRect.bottom = height;
if (down) {
int count = getChildCount();
if (count > 0) {
View view = getChildAt(count - 1);
mTempRect.bottom = view.getBottom() + getPaddingBottom();
mTempRect.top = mTempRect.bottom - height;
}
}
return scrollAndFocus(direction, mTempRect.top, mTempRect.bottom);
}
/**
* <p>Scrolls the view to make the area defined by <code>top</code> and
* <code>bottom</code> visible. This method attempts to give the focus
* to a component visible in this area. If no component can be focused in
* the new visible area, the focus is reclaimed by this ScrollView.</p>
*
* @param direction the scroll direction: {@link android.view.View#FOCUS_UP}
* to go upward, {@link android.view.View#FOCUS_DOWN} to downward
* @param top the top offset of the new area to be made visible
* @param bottom the bottom offset of the new area to be made visible
* @return true if the key event is consumed by this method, false otherwise
*/
private boolean scrollAndFocus(int direction, int top, int bottom) {
boolean handled = true;
int height = getHeight();
int containerTop = getScrollY();
int containerBottom = containerTop + height;
boolean up = direction == View.FOCUS_UP;
View newFocused = findFocusableViewInBounds(up, top, bottom);
if (newFocused == null) {
newFocused = this;
}
if (top >= containerTop && bottom <= containerBottom) {
handled = false;
} else {
int delta = up ? (top - containerTop) : (bottom - containerBottom);
doScrollY(delta);
}
if (newFocused != findFocus()) newFocused.requestFocus(direction);
return handled;
}
/**
* Handle scrolling in response to an up or down arrow click.
*
* @param direction The direction corresponding to the arrow key that was
* pressed
* @return True if we consumed the event, false otherwise
*/
protected boolean arrowScroll(int direction) {
View currentFocused = findFocus();
if (currentFocused == this) currentFocused = null;
View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused, direction);
final int maxJump = getMaxScrollAmount();
if (nextFocused != null && isWithinDeltaOfScreen(nextFocused, maxJump, getHeight())) {
nextFocused.getDrawingRect(mTempRect);
offsetDescendantRectToMyCoords(nextFocused, mTempRect);
int scrollDelta = computeScrollDeltaToGetChildRectOnScreen(mTempRect);
doScrollY(scrollDelta);
nextFocused.requestFocus(direction);
} else {
// no new focus
int scrollDelta = maxJump;
if (direction == View.FOCUS_UP && getScrollY() < scrollDelta) {
scrollDelta = getScrollY();
} else if (direction == View.FOCUS_DOWN) {
if (getChildCount() > 0) {
int daBottom = getChildAt(0).getBottom();
int screenBottom = getScrollY() + getHeight() - getPaddingBottom();
if (daBottom - screenBottom < maxJump) {
scrollDelta = daBottom - screenBottom;
}
}
}
if (scrollDelta == 0) {
return false;
}
doScrollY(direction == View.FOCUS_DOWN ? scrollDelta : -scrollDelta);
}
if (currentFocused != null && currentFocused.isFocused()
&& isOffScreen(currentFocused)) {
// previously focused item still has focus and is off screen, give
// it up (take it back to ourselves)
// (also, need to temporarily force FOCUS_BEFORE_DESCENDANTS so we are
// sure to
// get it)
final int descendantFocusability = getDescendantFocusability(); // save
setDescendantFocusability(ViewGroup.FOCUS_BEFORE_DESCENDANTS);
requestFocus();
setDescendantFocusability(descendantFocusability); // restore
}
return true;
}
/**
* @return whether the descendant of this scroll view is scrolled off
* screen.
*/
protected boolean isOffScreen(View descendant) {
return !isWithinDeltaOfScreen(descendant, 0, getHeight());
}
/**
* @return whether the descendant of this scroll view is within delta
* pixels of being on the screen.
*/
protected boolean isWithinDeltaOfScreen(View descendant, int delta, int height) {
descendant.getDrawingRect(mTempRect);
offsetDescendantRectToMyCoords(descendant, mTempRect);
return (mTempRect.bottom + delta) >= getScrollY()
&& (mTempRect.top - delta) <= (getScrollY() + height);
}
/**
* Smooth scroll by a Y delta
*
* @param delta the number of pixels to scroll by on the Y axis
*/
protected void doScrollY(int delta) {
if (delta != 0) {
if (mSmoothScrollingEnabled) {
smoothScrollBy(0, delta);
} else {
scrollBy(0, delta);
}
}
}
/**
* Like {@link View#scrollBy}, but scroll smoothly instead of immediately.
*
* @param dx the number of pixels to scroll by on the X axis
* @param dy the number of pixels to scroll by on the Y axis
*/
public final void smoothScrollBy(int dx, int dy) {
if (getChildCount() == 0) {
return;
}
if (!mScroller.isFinished()) {
mScroller.abortAnimation();
}
final int height = getHeight() - getPaddingBottom() - getPaddingTop();
final int bottom = getChildAt(0).getHeight();
final int maxY = Math.max(0, bottom - height);
final int scrollY = getScrollY();
dy = Math.max(0, Math.min(scrollY + dy, maxY)) - scrollY;
mScroller.startScroll(getScrollX(), scrollY, dx, dy, computeTime(dy));
postInvalidateOnAnimation();
}
private int computeTime(int d) {
int time = Math.abs(d);
if (time < ANIMATED_SCROLL_GAP) {
time = ANIMATED_SCROLL_GAP;
} else {
double index = 1 + Math.pow(((float) ANIMATED_SCROLL_GAP / time), time / ANIMATED_SCROLL_GAP);
time = (int) (ANIMATED_SCROLL_GAP * index);
}
return time;
}
/**
* Like {@link #scrollTo}, but scroll smoothly instead of immediately.
*
* @param x the position where to scroll on the X axis
* @param y the position where to scroll on the Y axis
*/
public final void smoothScrollTo(int x, int y) {
smoothScrollBy(x - getScrollX(), y - getScrollY());
}
/**
* <p>The scroll range of a scroll view is the overall height of all of its
* children.</p>
*/
@Override
protected int computeVerticalScrollRange() {
final int count = getChildCount();
final int contentHeight = getHeight() - getPaddingBottom() - getPaddingTop();
if (count == 0) {
return contentHeight;
}
int scrollRange = getChildAt(0).getBottom();
final int scrollY = getScrollY();
final int overscrollBottom = Math.max(0, scrollRange - contentHeight);
if (scrollY < 0) {
scrollRange -= scrollY;
} else if (scrollY > overscrollBottom) {
scrollRange += scrollY - overscrollBottom;
}
return scrollRange;
}
@Override
protected int computeVerticalScrollOffset() {
return Math.max(0, super.computeVerticalScrollOffset());
}
@Override
protected void measureChild(View child, int parentWidthMeasureSpec, int parentHeightMeasureSpec) {
ViewGroup.LayoutParams lp = child.getLayoutParams();
int childWidthMeasureSpec;
int childHeightMeasureSpec;
childWidthMeasureSpec = getChildMeasureSpec(parentWidthMeasureSpec, getPaddingLeft()
+ getPaddingRight(), lp.width);
childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED);
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
@Override
protected void measureChildWithMargins(View child, int parentWidthMeasureSpec, int widthUsed,
int parentHeightMeasureSpec, int heightUsed) {
final MarginLayoutParams lp = (MarginLayoutParams) child.getLayoutParams();
final int childWidthMeasureSpec = getChildMeasureSpec(parentWidthMeasureSpec,
getPaddingLeft() + getPaddingRight() + lp.leftMargin + lp.rightMargin
+ widthUsed, lp.width);
final int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(
lp.topMargin + lp.bottomMargin, MeasureSpec.UNSPECIFIED);
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
@Override
public void computeScroll() {
if (mScroller.computeScrollOffset()) {
int oldX = getScrollX();
int oldY = getScrollY();
int x = mScroller.getCurrX();
int y = mScroller.getCurrY();
if (oldX != x || oldY != y) {
final int range = getScrollRange();
final int overscrollMode = getOverScrollMode();
final boolean canOverscroll = overscrollMode == OVER_SCROLL_ALWAYS ||
(overscrollMode == OVER_SCROLL_IF_CONTENT_SCROLLS && range > 0);
overScrollBy(x - oldX, y - oldY, oldX, oldY, 0, range,
0, mOverflingDistance, false);
// onScrollChanged(getScrollX(), getScrollY(), oldX, oldY);
// if (canOverscroll) {
// if (y < 0 && oldY >= 0) {
// mEdgeGlowTop.onAbsorb((int) mScroller.getCurrVelocity());
// } else if (y > range && oldY <= range) {
// mEdgeGlowBottom.onAbsorb((int) mScroller.getCurrVelocity());
// }
// }
}
// if (!awakenScrollBars()) {
// Keep on drawing until the animation has finished.
// postInvalidateOnAnimation();
// }
} else
{
}
}
/**
* Scrolls the view to the given child.
*
* @param child the View to scroll to
*/
private void scrollToChild(View child) {
child.getDrawingRect(mTempRect);
/* Offset from child's local coordinates to ScrollView coordinates */
offsetDescendantRectToMyCoords(child, mTempRect);
int scrollDelta = computeScrollDeltaToGetChildRectOnScreen(mTempRect);
if (scrollDelta != 0) {
scrollBy(0, scrollDelta);
}
}
/**
* If rect is off screen, scroll just enough to get it (or at least the
* first screen size chunk of it) on screen.
*
* @param rect The rectangle.
* @param immediate True to scroll immediately without animation
* @return true if scrolling was performed
*/
private boolean scrollToChildRect(Rect rect, boolean immediate) {
final int delta = computeScrollDeltaToGetChildRectOnScreen(rect);
final boolean scroll = delta != 0;
if (scroll) {
if (immediate) {
scrollBy(0, delta);
} else {
smoothScrollBy(0, delta);
}
}
return scroll;
}
/**
* Compute the amount to scroll in the Y direction in order to get
* a rectangle completely on the screen (or, if taller than the screen,
* at least the first screen size chunk of it).
*
* @param rect The rect.
* @return The scroll delta.
*/
protected int computeScrollDeltaToGetChildRectOnScreen(Rect rect) {
if (getChildCount() == 0) return 0;
int height = getHeight();
int screenTop = getScrollY();
int screenBottom = screenTop + height;
int fadingEdge = getVerticalFadingEdgeLength();
// leave room for top fading edge as long as rect isn't at very top
if (rect.top > 0) {
screenTop += fadingEdge;
}
// leave room for bottom fading edge as long as rect isn't at very bottom
if (rect.bottom < getChildAt(0).getHeight()) {
screenBottom -= fadingEdge;
}
int scrollYDelta = 0;
if (rect.bottom > screenBottom && rect.top > screenTop) {
// need to move down to get it in view: move down just enough so
// that the entire rectangle is in view (or at least the first
// screen size chunk).
if (rect.height() > height) {
// just enough to get screen size chunk on
scrollYDelta += (rect.top - screenTop);
} else {
// get entire rect at bottom of screen
scrollYDelta += (rect.bottom - screenBottom);
}
// make sure we aren't scrolling beyond the end of our content
int bottom = getChildAt(0).getBottom();
int distanceToBottom = bottom - screenBottom;
scrollYDelta = Math.min(scrollYDelta, distanceToBottom);
} else if (rect.top < screenTop && rect.bottom < screenBottom) {
// need to move up to get it in view: move up just enough so that
// entire rectangle is in view (or at least the first screen
// size chunk of it).
if (rect.height() > height) {
// screen size chunk
scrollYDelta -= (screenBottom - rect.bottom);
} else {
// entire rect at top
scrollYDelta -= (screenTop - rect.top);
}
// make sure we aren't scrolling any further than the top our content
scrollYDelta = Math.max(scrollYDelta, -getScrollY());
}
return scrollYDelta;
}
@Override
public void requestChildFocus(View child, View focused) {
if (!mIsLayoutDirty) {
scrollToChild(focused);
} else {
// The child may not be laid out yet, we can't compute the scroll yet
mChildToScrollTo = focused;
}
super.requestChildFocus(child, focused);
}
/**
* When looking for focus in children of a scroll view, need to be a little
* more careful not to give focus to something that is scrolled off screen.
* <p>
* This is more expensive than the default {@link android.view.ViewGroup}
* implementation, otherwise this behavior might have been made the default.
*/
@Override
protected boolean onRequestFocusInDescendants(int direction,
Rect previouslyFocusedRect) {
// convert from forward / backward notation to up / down / left / right
// (ugh).
if (direction == View.FOCUS_FORWARD) {
direction = View.FOCUS_DOWN;
} else if (direction == View.FOCUS_BACKWARD) {
direction = View.FOCUS_UP;
}
final View nextFocus = previouslyFocusedRect == null ?
FocusFinder.getInstance().findNextFocus(this, null, direction) :
FocusFinder.getInstance().findNextFocusFromRect(this,
previouslyFocusedRect, direction);
if (nextFocus == null) {
return false;
}
if (isOffScreen(nextFocus)) {
return false;
}
return nextFocus.requestFocus(direction, previouslyFocusedRect);
}
@Override
public boolean requestChildRectangleOnScreen(View child, Rect rectangle,
boolean immediate) {
// offset into coordinate space of this scroll view
rectangle.offset(child.getLeft() - child.getScrollX(),
child.getTop() - child.getScrollY());
return scrollToChildRect(rectangle, immediate);
}
@Override
public void requestLayout() {
mIsLayoutDirty = true;
super.requestLayout();
}
@Override
protected void onDetachedFromWindow() {
super.onDetachedFromWindow();
}
@Override
protected void onLayout(boolean changed, int l, int t, int r, int b) {
super.onLayout(changed, l, t, r, b);
if (!changed) {
return;
}
mIsLayoutDirty = false;
// Give a child focus if it needs it
if (mChildToScrollTo != null && isViewDescendantOf(mChildToScrollTo, this)) {
scrollToChild(mChildToScrollTo);
}
mChildToScrollTo = null;
if (!isLaidOut()) {
if (mSavedState != null) {
setScrollY(mSavedState.scrollPosition);
mSavedState = null;
} // mScrollY default value is "0"
final int childHeight = (getChildCount() > 0) ? getChildAt(0).getMeasuredHeight() : 0;
final int scrollRange = Math.max(0,
childHeight - (b - t - getPaddingBottom() - getPaddingTop()));
// Don't forget to clamp
if (getScrollY() > scrollRange) {
setScrollY(scrollRange);
} else if (getScrollY() < 0) {
setScrollY(0);
}
}
// Calling this with the present values causes it to re-claim them
scrollTo(getScrollX(), getScrollY());
}
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
View currentFocused = findFocus();
if (null == currentFocused || this == currentFocused)
return;
// If the currently-focused view was visible on the screen when the
// screen was at the old height, then scroll the screen to make that
// view visible with the new screen height.
if (isWithinDeltaOfScreen(currentFocused, 0, oldh)) {
currentFocused.getDrawingRect(mTempRect);
offsetDescendantRectToMyCoords(currentFocused, mTempRect);
int scrollDelta = computeScrollDeltaToGetChildRectOnScreen(mTempRect);
doScrollY(scrollDelta);
}
}
/**
* Return true if child is a descendant of parent, (or equal to the parent).
*/
private static boolean isViewDescendantOf(View child, View parent) {
if (child == parent) {
return true;
}
final ViewParent theParent = child.getParent();
return (theParent instanceof ViewGroup) && isViewDescendantOf((View) theParent, parent);
}
/**
* Fling the scroll view
*
* @param velocityY The initial velocity in the Y direction. Positive
* numbers mean that the finger/cursor is moving down the screen,
* which means we want to scroll towards the top.
*/
public void fling(int velocityY) {
if (getChildCount() > 0) {
int height = getHeight() - getPaddingBottom() - getPaddingTop();
int bottom = getChildAt(0).getHeight();
mScroller.fling(getScrollX(), getScrollY(), 0, velocityY, 0, 0, 0,
Math.max(0, bottom - height), 0, height / 2);
postInvalidateOnAnimation();
}
}
private void flingWithNestedDispatch(int velocityY) {
final boolean canFling = (getScrollY() > 0 || velocityY > 0) &&
(getScrollY() < getScrollRange() || velocityY < 0);
if (!dispatchNestedPreFling(0, velocityY)) {
dispatchNestedFling(0, velocityY, canFling);
if (canFling) {
fling(velocityY);
}
}
}
/**
* {@inheritDoc}
* <p>
* <p>This version also clamps the scrolling to the bounds of our child.
*/
@Override
public void scrollTo(int x, int y) {
// we rely on the fact the View.scrollBy calls scrollTo.
if (getChildCount() > 0) {
View child = getChildAt(0);
x = clamp(x, getWidth() - getPaddingRight() - getPaddingLeft(), child.getWidth());
y = clamp(y, getHeight() - getPaddingBottom() - getPaddingTop(), child.getHeight());
if (x != getScrollX() || y != getScrollY()) {
super.scrollTo(x, y);
}
}
}
@Override
public void setOverScrollMode(int mode) {
if (mode != OVER_SCROLL_NEVER) {
if (mEdgeGlowTop == null) {
Context context = getContext();
mEdgeGlowTop = new EdgeEffect(context);
mEdgeGlowBottom = new EdgeEffect(context);
}
} else {
mEdgeGlowTop = null;
mEdgeGlowBottom = null;
}
super.setOverScrollMode(mode);
}
@Override
public boolean onStartNestedScroll(View child, View target, int nestedScrollAxes) {
return (nestedScrollAxes & SCROLL_AXIS_VERTICAL) != 0;
}
@Override
public void onNestedScrollAccepted(View child, View target, int axes) {
super.onNestedScrollAccepted(child, target, axes);
startNestedScroll(SCROLL_AXIS_VERTICAL);
}
/**
* @inheritDoc
*/
@Override
public void onStopNestedScroll(View target) {
super.onStopNestedScroll(target);
}
@Override
public void onNestedScroll(View target, int dxConsumed, int dyConsumed,
int dxUnconsumed, int dyUnconsumed) {
final int oldScrollY = getScrollY();
scrollBy(0, dyUnconsumed);
final int myConsumed = getScrollY() - oldScrollY;
final int myUnconsumed = dyUnconsumed - myConsumed;
dispatchNestedScroll(0, myConsumed, 0, myUnconsumed, null);
}
/**
* @inheritDoc
*/
@Override
public boolean onNestedFling(View target, float velocityX, float velocityY, boolean consumed) {
if (!consumed) {
flingWithNestedDispatch((int) velocityY);
return true;
}
return false;
}
// float time = 0;
// float currentTime = 0;
@Override
public void draw(Canvas canvas) {
super.draw(canvas);
if (mEdgeGlowTop != null) {
final int scrollY = getScrollY();
if (!mEdgeGlowTop.isFinished()) {
final int restoreCount = canvas.save();
final int width = getWidth() - getPaddingLeft() - getPaddingRight();
canvas.translate(getPaddingLeft(), Math.min(0, scrollY));
mEdgeGlowTop.setSize(width, getHeight());
if (mEdgeGlowTop.draw(canvas)) {
postInvalidateOnAnimation();
}
canvas.restoreToCount(restoreCount);
}
if (!mEdgeGlowBottom.isFinished()) {
final int restoreCount = canvas.save();
final int width = getWidth() - getPaddingLeft() - getPaddingRight();
final int height = getHeight();
canvas.translate(-width + getPaddingLeft(),
Math.max(getScrollRange(), scrollY) + height);
canvas.rotate(180, width, 0);
mEdgeGlowBottom.setSize(width, height);
if (mEdgeGlowBottom.draw(canvas)) {
postInvalidateOnAnimation();
}
canvas.restoreToCount(restoreCount);
}
}
// currentTime = System.currentTimeMillis();
// if (0 != time) {
// LogUtils.i(TAG, "onDraw: time : " + (currentTime - time));
// }
// time = currentTime;
}
private static int clamp(int n, int my, int child) {
if (my >= child || n < 0) {
/* my >= child is this case:
* |--------------- me ---------------|
* |------ child ------|
* or
* |--------------- me ---------------|
* |------ child ------|
* or
* |--------------- me ---------------|
* |------ child ------|
*
* n < 0 is this case:
* |------ me ------|
* |-------- child --------|
* |-- mScrollX --|
*/
return 0;
}
if ((my + n) > child) {
/* this case:
* |------ me ------|
* |------ child ------|
* |-- mScrollX --|
*/
return child - my;
}
return n;
}
@Override
protected void onRestoreInstanceState(Parcelable state) {
if (mContext.getApplicationInfo().targetSdkVersion <= Build.VERSION_CODES.JELLY_BEAN_MR2) {
// Some old apps reused IDs in ways they shouldn't have.
// Don't break them, but they don't get scroll state restoration.
super.onRestoreInstanceState(state);
return;
}
MScrollView.SavedState ss = (MScrollView.SavedState) state;
super.onRestoreInstanceState(ss.getSuperState());
mSavedState = ss;
requestLayout();
}
@Override
protected Parcelable onSaveInstanceState() {
if (mContext.getApplicationInfo().targetSdkVersion <= Build.VERSION_CODES.JELLY_BEAN_MR2) {
// Some old apps reused IDs in ways they shouldn't have.
// Don't break them, but they don't get scroll state restoration.
return super.onSaveInstanceState();
}
Parcelable superState = super.onSaveInstanceState();
MScrollView.SavedState ss = new MScrollView.SavedState(superState);
ss.scrollPosition = getScrollY();
return ss;
}
static class SavedState extends BaseSavedState {
public int scrollPosition;
SavedState(Parcelable superState) {
super(superState);
}
public SavedState(Parcel source) {
super(source);
scrollPosition = source.readInt();
}
@Override
public void writeToParcel(Parcel dest, int flags) {
super.writeToParcel(dest, flags);
dest.writeInt(scrollPosition);
}
@Override
public String toString() {
return "HorizontalScrollView.SavedState{"
+ Integer.toHexString(System.identityHashCode(this))
+ " scrollPosition=" + scrollPosition + "}";
}
public static final Parcelable.Creator<MScrollView.SavedState> CREATOR
= new Parcelable.Creator<MScrollView.SavedState>() {
public MScrollView.SavedState createFromParcel(Parcel in) {
return new MScrollView.SavedState(in);
}
public MScrollView.SavedState[] newArray(int size) {
return new MScrollView.SavedState[size];
}
};
}
}
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