open-keychain/OpenKeychain/src/main/java/android/support/v4/widget/FlingNestedScrollView.java
2018-01-24 01:32:15 +01:00

1359 lines
53 KiB
Java

/*
* Copyright (C) 2015 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.support.v4.widget;
import java.util.ArrayList;
import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Rect;
import android.os.Bundle;
import android.os.Parcel;
import android.os.Parcelable;
import android.support.v4.view.AccessibilityDelegateCompat;
import android.support.v4.view.MotionEventCompat;
import android.support.v4.view.NestedScrollingChild;
import android.support.v4.view.NestedScrollingChildHelper;
import android.support.v4.view.NestedScrollingParent;
import android.support.v4.view.NestedScrollingParentHelper;
import android.support.v4.view.VelocityTrackerCompat;
import android.support.v4.view.ViewCompat;
import android.support.v4.view.accessibility.AccessibilityEventCompat;
import android.support.v4.view.accessibility.AccessibilityNodeInfoCompat;
import android.support.v4.view.accessibility.AccessibilityRecordCompat;
import android.util.AttributeSet;
import android.util.TypedValue;
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.ViewGroup;
import android.view.ViewParent;
import android.view.accessibility.AccessibilityEvent;
import android.view.animation.AnimationUtils;
import android.widget.FrameLayout;
import android.widget.ScrollView;
import timber.log.Timber;
/**
* Workaround for bug in support lib. From https://code.google.com/p/android/issues/detail?id=177729
*
* Also see workaround with padding in view_key_fragment.xml
*/
public class FlingNestedScrollView extends FrameLayout implements NestedScrollingParent, NestedScrollingChild {
static final int ANIMATED_SCROLL_GAP = 250;
static final float MAX_SCROLL_FACTOR = 0.5F;
private static final String TAG = "FlingNestedScrollView";
private long mLastScroll;
private final Rect mTempRect;
private ScrollerCompat mScroller;
private EdgeEffectCompat mEdgeGlowTop;
private EdgeEffectCompat mEdgeGlowBottom;
private int mLastMotionY;
private boolean mIsLayoutDirty;
private boolean mIsLaidOut;
private View mChildToScrollTo;
private boolean mIsBeingDragged;
private VelocityTracker mVelocityTracker;
private boolean mFillViewport;
private boolean mSmoothScrollingEnabled;
private int mTouchSlop;
private int mMinimumVelocity;
private int mMaximumVelocity;
private int mActivePointerId;
private final int[] mScrollOffset;
private final int[] mScrollConsumed;
private int mNestedYOffset;
private static final int INVALID_POINTER = -1;
private FlingNestedScrollView.SavedState mSavedState;
private static final FlingNestedScrollView.AccessibilityDelegate ACCESSIBILITY_DELEGATE = new FlingNestedScrollView.AccessibilityDelegate();
private static final int[] SCROLLVIEW_STYLEABLE = new int[]{16843130};
private final NestedScrollingParentHelper mParentHelper;
private final NestedScrollingChildHelper mChildHelper;
private float mVerticalScrollFactor;
public FlingNestedScrollView(Context context) {
this(context, null);
}
public FlingNestedScrollView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
public FlingNestedScrollView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
this.mTempRect = new Rect();
this.mIsLayoutDirty = true;
this.mIsLaidOut = false;
this.mChildToScrollTo = null;
this.mIsBeingDragged = false;
this.mSmoothScrollingEnabled = true;
this.mActivePointerId = -1;
this.mScrollOffset = new int[2];
this.mScrollConsumed = new int[2];
this.initScrollView();
TypedArray a = context.obtainStyledAttributes(attrs, SCROLLVIEW_STYLEABLE, defStyleAttr, 0);
this.setFillViewport(a.getBoolean(0, false));
a.recycle();
this.mParentHelper = new NestedScrollingParentHelper(this);
this.mChildHelper = new NestedScrollingChildHelper(this);
this.setNestedScrollingEnabled(true);
ViewCompat.setAccessibilityDelegate(this, ACCESSIBILITY_DELEGATE);
}
public void setNestedScrollingEnabled(boolean enabled) {
this.mChildHelper.setNestedScrollingEnabled(enabled);
}
public boolean isNestedScrollingEnabled() {
return this.mChildHelper.isNestedScrollingEnabled();
}
public boolean startNestedScroll(int axes) {
return this.mChildHelper.startNestedScroll(axes);
}
public void stopNestedScroll() {
this.mChildHelper.stopNestedScroll();
}
public boolean hasNestedScrollingParent() {
return this.mChildHelper.hasNestedScrollingParent();
}
public boolean dispatchNestedScroll(int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed, int[] offsetInWindow) {
return this.mChildHelper.dispatchNestedScroll(dxConsumed, dyConsumed, dxUnconsumed, dyUnconsumed, offsetInWindow);
}
public boolean dispatchNestedPreScroll(int dx, int dy, int[] consumed, int[] offsetInWindow) {
return this.mChildHelper.dispatchNestedPreScroll(dx, dy, consumed, offsetInWindow);
}
public boolean dispatchNestedFling(float velocityX, float velocityY, boolean consumed) {
return this.mChildHelper.dispatchNestedFling(velocityX, velocityY, consumed);
}
public boolean dispatchNestedPreFling(float velocityX, float velocityY) {
return this.mChildHelper.dispatchNestedPreFling(velocityX, velocityY);
}
public boolean onStartNestedScroll(View child, View target, int nestedScrollAxes) {
return (nestedScrollAxes & 2) != 0;
}
public void onNestedScrollAccepted(View child, View target, int nestedScrollAxes) {
this.mParentHelper.onNestedScrollAccepted(child, target, nestedScrollAxes);
this.startNestedScroll(2);
}
public void onStopNestedScroll(View target) {
this.stopNestedScroll();
}
public void onNestedScroll(View target, int dxConsumed, int dyConsumed, int dxUnconsumed, int dyUnconsumed) {
int oldScrollY = this.getScrollY();
this.scrollBy(0, dyUnconsumed);
int myConsumed = this.getScrollY() - oldScrollY;
int myUnconsumed = dyUnconsumed - myConsumed;
this.dispatchNestedScroll(0, myConsumed, 0, myUnconsumed, null);
}
public void onNestedPreScroll(View target, int dx, int dy, int[] consumed) {
}
public boolean onNestedFling(View target, float velocityX, float velocityY, boolean consumed) {
if(!consumed) {
this.flingWithNestedDispatch((int)velocityY);
return true;
} else {
return false;
}
}
public boolean onNestedPreFling(View target, float velocityX, float velocityY) {
return false;
}
public int getNestedScrollAxes() {
return this.mParentHelper.getNestedScrollAxes();
}
public boolean shouldDelayChildPressedState() {
return true;
}
protected float getTopFadingEdgeStrength() {
if(this.getChildCount() == 0) {
return 0.0F;
} else {
int length = this.getVerticalFadingEdgeLength();
int scrollY = this.getScrollY();
return scrollY < length?(float)scrollY / (float)length:1.0F;
}
}
protected float getBottomFadingEdgeStrength() {
if(this.getChildCount() == 0) {
return 0.0F;
} else {
int length = this.getVerticalFadingEdgeLength();
int bottomEdge = this.getHeight() - this.getPaddingBottom();
int span = this.getChildAt(0).getBottom() - this.getScrollY() - bottomEdge;
return span < length?(float)span / (float)length:1.0F;
}
}
public int getMaxScrollAmount() {
return (int)(0.5F * (float)this.getHeight());
}
private void initScrollView() {
this.mScroller = ScrollerCompat.create(this.getContext());
this.setFocusable(true);
//noinspection ResourceType
this.setDescendantFocusability(262144);
this.setWillNotDraw(false);
ViewConfiguration configuration = ViewConfiguration.get(this.getContext());
this.mTouchSlop = configuration.getScaledTouchSlop();
this.mMinimumVelocity = configuration.getScaledMinimumFlingVelocity();
this.mMaximumVelocity = configuration.getScaledMaximumFlingVelocity();
}
public void addView(View child) {
if(this.getChildCount() > 0) {
throw new IllegalStateException("ScrollView can host only one direct child");
} else {
super.addView(child);
}
}
public void addView(View child, int index) {
if(this.getChildCount() > 0) {
throw new IllegalStateException("ScrollView can host only one direct child");
} else {
super.addView(child, index);
}
}
public void addView(View child, LayoutParams params) {
if(this.getChildCount() > 0) {
throw new IllegalStateException("ScrollView can host only one direct child");
} else {
super.addView(child, params);
}
}
public void addView(View child, int index, LayoutParams params) {
if(this.getChildCount() > 0) {
throw new IllegalStateException("ScrollView can host only one direct child");
} else {
super.addView(child, index, params);
}
}
private boolean canScroll() {
View child = this.getChildAt(0);
if(child != null) {
int childHeight = child.getHeight();
return this.getHeight() < childHeight + this.getPaddingTop() + this.getPaddingBottom();
} else {
return false;
}
}
public boolean isFillViewport() {
return this.mFillViewport;
}
public void setFillViewport(boolean fillViewport) {
if(fillViewport != this.mFillViewport) {
this.mFillViewport = fillViewport;
this.requestLayout();
}
}
public boolean isSmoothScrollingEnabled() {
return this.mSmoothScrollingEnabled;
}
public void setSmoothScrollingEnabled(boolean smoothScrollingEnabled) {
this.mSmoothScrollingEnabled = smoothScrollingEnabled;
}
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if(this.mFillViewport) {
int heightMode = MeasureSpec.getMode(heightMeasureSpec);
if(heightMode != 0) {
if(this.getChildCount() > 0) {
View child = this.getChildAt(0);
int height = this.getMeasuredHeight();
if(child.getMeasuredHeight() < height) {
android.widget.FrameLayout.LayoutParams lp = (android.widget.FrameLayout.LayoutParams)child.getLayoutParams();
int childWidthMeasureSpec = getChildMeasureSpec(widthMeasureSpec, this.getPaddingLeft() + this.getPaddingRight(), lp.width);
height -= this.getPaddingTop();
height -= this.getPaddingBottom();
//noinspection ResourceType
int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(height, 1073741824);
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
}
}
}
}
public boolean dispatchKeyEvent(KeyEvent event) {
return super.dispatchKeyEvent(event) || this.executeKeyEvent(event);
}
public boolean executeKeyEvent(KeyEvent event) {
this.mTempRect.setEmpty();
if(this.canScroll()) {
boolean handled1 = false;
if(event.getAction() == 0) {
switch(event.getKeyCode()) {
case 19:
if(!event.isAltPressed()) {
handled1 = this.arrowScroll(33);
} else {
handled1 = this.fullScroll(33);
}
break;
case 20:
if(!event.isAltPressed()) {
handled1 = this.arrowScroll(130);
} else {
handled1 = this.fullScroll(130);
}
break;
case 62:
this.pageScroll(event.isShiftPressed()?33:130);
}
}
return handled1;
} else if(this.isFocused() && event.getKeyCode() != 4) {
View handled = this.findFocus();
if(handled == this) {
handled = null;
}
View nextFocused = FocusFinder.getInstance().findNextFocus(this, handled, 130);
return nextFocused != null && nextFocused != this && nextFocused.requestFocus(130);
} else {
return false;
}
}
private boolean inChild(int x, int y) {
if(this.getChildCount() <= 0) {
return false;
} else {
int scrollY = this.getScrollY();
View child = this.getChildAt(0);
return y >= child.getTop() - scrollY && y < child.getBottom() - scrollY && x >= child.getLeft() && x < child.getRight();
}
}
private void initOrResetVelocityTracker() {
if(this.mVelocityTracker == null) {
this.mVelocityTracker = VelocityTracker.obtain();
} else {
this.mVelocityTracker.clear();
}
}
private void initVelocityTrackerIfNotExists() {
if(this.mVelocityTracker == null) {
this.mVelocityTracker = VelocityTracker.obtain();
}
}
private void recycleVelocityTracker() {
if(this.mVelocityTracker != null) {
this.mVelocityTracker.recycle();
this.mVelocityTracker = null;
}
}
public void requestDisallowInterceptTouchEvent(boolean disallowIntercept) {
if(disallowIntercept) {
this.recycleVelocityTracker();
}
super.requestDisallowInterceptTouchEvent(disallowIntercept);
}
public boolean onInterceptTouchEvent(MotionEvent ev) {
int action = ev.getAction();
if(action == 2 && this.mIsBeingDragged) {
return true;
} else if(this.getScrollY() == 0 && !ViewCompat.canScrollVertically(this, 1)) {
return false;
} else {
int y;
switch(action & 255) {
case 0:
y = (int)ev.getY();
if(!this.inChild((int)ev.getX(), y)) {
this.mIsBeingDragged = false;
this.recycleVelocityTracker();
} else {
this.mLastMotionY = y;
this.mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
this.initOrResetVelocityTracker();
this.mVelocityTracker.addMovement(ev);
this.mIsBeingDragged = !this.mScroller.isFinished();
this.startNestedScroll(2);
}
break;
case 1:
case 3:
this.mIsBeingDragged = false;
this.mActivePointerId = -1;
this.recycleVelocityTracker();
this.stopNestedScroll();
break;
case 2:
y = this.mActivePointerId;
if(y != -1) {
int pointerIndex = MotionEventCompat.findPointerIndex(ev, y);
if(pointerIndex == -1) {
Timber.e("Invalid pointerId=" + y + " in onInterceptTouchEvent");
} else {
int y1 = (int)MotionEventCompat.getY(ev, pointerIndex);
int yDiff = Math.abs(y1 - this.mLastMotionY);
if(yDiff > this.mTouchSlop && (this.getNestedScrollAxes() & 2) == 0) {
this.mIsBeingDragged = true;
this.mLastMotionY = y1;
this.initVelocityTrackerIfNotExists();
this.mVelocityTracker.addMovement(ev);
this.mNestedYOffset = 0;
ViewParent parent = this.getParent();
if(parent != null) {
parent.requestDisallowInterceptTouchEvent(true);
}
}
}
}
case 4:
case 5:
default:
break;
case 6:
this.onSecondaryPointerUp(ev);
}
return this.mIsBeingDragged;
}
}
public boolean onTouchEvent(MotionEvent ev) {
this.initVelocityTrackerIfNotExists();
MotionEvent vtev = MotionEvent.obtain(ev);
int actionMasked = MotionEventCompat.getActionMasked(ev);
if(actionMasked == 0) {
this.mNestedYOffset = 0;
}
vtev.offsetLocation(0.0F, (float)this.mNestedYOffset);
int index;
int initialVelocity;
switch(actionMasked) {
case 0:
if(this.getChildCount() == 0) {
return false;
}
if(this.mIsBeingDragged = !this.mScroller.isFinished()) {
ViewParent activePointerIndex1 = this.getParent();
if(activePointerIndex1 != null) {
activePointerIndex1.requestDisallowInterceptTouchEvent(true);
}
}
if(!this.mScroller.isFinished()) {
this.mScroller.abortAnimation();
}
this.mLastMotionY = (int)ev.getY();
this.mActivePointerId = MotionEventCompat.getPointerId(ev, 0);
this.startNestedScroll(2);
break;
case 1:
if(this.mIsBeingDragged) {
VelocityTracker index2 = this.mVelocityTracker;
index2.computeCurrentVelocity(1000, (float)this.mMaximumVelocity);
initialVelocity = (int) VelocityTrackerCompat.getYVelocity(index2, this.mActivePointerId);
if(Math.abs(initialVelocity) > this.mMinimumVelocity) {
this.flingWithNestedDispatch(-initialVelocity);
}
this.mActivePointerId = -1;
this.endDrag();
}
break;
case 2:
int activePointerIndex = MotionEventCompat.findPointerIndex(ev, this.mActivePointerId);
if(activePointerIndex == -1) {
Timber.e("Invalid pointerId=" + this.mActivePointerId + " in onTouchEvent");
} else {
int y = (int)MotionEventCompat.getY(ev, activePointerIndex);
int deltaY = this.mLastMotionY - y;
if(this.dispatchNestedPreScroll(0, deltaY, this.mScrollConsumed, this.mScrollOffset)) {
deltaY -= this.mScrollConsumed[1];
vtev.offsetLocation(0.0F, (float)this.mScrollOffset[1]);
this.mNestedYOffset += this.mScrollOffset[1];
}
if(!this.mIsBeingDragged && Math.abs(deltaY) > this.mTouchSlop) {
ViewParent index1 = this.getParent();
if(index1 != null) {
index1.requestDisallowInterceptTouchEvent(true);
}
this.mIsBeingDragged = true;
if(deltaY > 0) {
deltaY -= this.mTouchSlop;
} else {
deltaY += this.mTouchSlop;
}
}
if(this.mIsBeingDragged) {
this.mLastMotionY = y - this.mScrollOffset[1];
index = this.getScrollY();
initialVelocity = this.getScrollRange();
int overscrollMode = ViewCompat.getOverScrollMode(this);
boolean canOverscroll = overscrollMode == 0 || overscrollMode == 1 && initialVelocity > 0;
if(this.overScrollByCompat(0, deltaY, 0, this.getScrollY(), 0, initialVelocity, 0, 0, true) && !this.hasNestedScrollingParent()) {
this.mVelocityTracker.clear();
}
int scrolledDeltaY = this.getScrollY() - index;
int unconsumedY = deltaY - scrolledDeltaY;
if(this.dispatchNestedScroll(0, scrolledDeltaY, 0, unconsumedY, this.mScrollOffset)) {
this.mLastMotionY -= this.mScrollOffset[1];
vtev.offsetLocation(0.0F, (float)this.mScrollOffset[1]);
this.mNestedYOffset += this.mScrollOffset[1];
} else if(canOverscroll) {
this.ensureGlows();
int pulledToY = index + deltaY;
if(pulledToY < 0) {
this.mEdgeGlowTop.onPull((float)deltaY / (float)this.getHeight(), MotionEventCompat.getX(ev, activePointerIndex) / (float)this.getWidth());
if(!this.mEdgeGlowBottom.isFinished()) {
this.mEdgeGlowBottom.onRelease();
}
} else if(pulledToY > initialVelocity) {
this.mEdgeGlowBottom.onPull((float)deltaY / (float)this.getHeight(), 1.0F - MotionEventCompat.getX(ev, activePointerIndex) / (float)this.getWidth());
if(!this.mEdgeGlowTop.isFinished()) {
this.mEdgeGlowTop.onRelease();
}
}
if(this.mEdgeGlowTop != null && (!this.mEdgeGlowTop.isFinished() || !this.mEdgeGlowBottom.isFinished())) {
ViewCompat.postInvalidateOnAnimation(this);
}
}
}
}
break;
case 3:
if(this.mIsBeingDragged && this.getChildCount() > 0) {
this.mActivePointerId = -1;
this.endDrag();
}
case 4:
default:
break;
case 5:
index = MotionEventCompat.getActionIndex(ev);
this.mLastMotionY = (int)MotionEventCompat.getY(ev, index);
this.mActivePointerId = MotionEventCompat.getPointerId(ev, index);
break;
case 6:
this.onSecondaryPointerUp(ev);
this.mLastMotionY = (int)MotionEventCompat.getY(ev, MotionEventCompat.findPointerIndex(ev, this.mActivePointerId));
}
if(this.mVelocityTracker != null) {
this.mVelocityTracker.addMovement(vtev);
}
vtev.recycle();
return true;
}
private void onSecondaryPointerUp(MotionEvent ev) {
int pointerIndex = (ev.getAction() & '\uff00') >> 8;
int pointerId = MotionEventCompat.getPointerId(ev, pointerIndex);
if(pointerId == this.mActivePointerId) {
int newPointerIndex = pointerIndex == 0?1:0;
this.mLastMotionY = (int)MotionEventCompat.getY(ev, newPointerIndex);
this.mActivePointerId = MotionEventCompat.getPointerId(ev, newPointerIndex);
if(this.mVelocityTracker != null) {
this.mVelocityTracker.clear();
}
}
}
public boolean onGenericMotionEvent(MotionEvent event) {
if((MotionEventCompat.getSource(event) & 2) != 0) {
switch(event.getAction()) {
case 8:
if(!this.mIsBeingDragged) {
float vscroll = MotionEventCompat.getAxisValue(event, 9);
if(vscroll != 0.0F) {
int delta = (int)(vscroll * this.getVerticalScrollFactorCompat());
int range = this.getScrollRange();
int oldScrollY = this.getScrollY();
int newScrollY = oldScrollY - delta;
if(newScrollY < 0) {
newScrollY = 0;
} else if(newScrollY > range) {
newScrollY = range;
}
if(newScrollY != oldScrollY) {
super.scrollTo(this.getScrollX(), newScrollY);
return true;
}
}
}
}
}
return false;
}
private float getVerticalScrollFactorCompat() {
if(this.mVerticalScrollFactor == 0.0F) {
TypedValue outValue = new TypedValue();
Context context = this.getContext();
if(!context.getTheme().resolveAttribute(16842829, outValue, true)) {
throw new IllegalStateException("Expected theme to define listPreferredItemHeight.");
}
this.mVerticalScrollFactor = outValue.getDimension(context.getResources().getDisplayMetrics());
}
return this.mVerticalScrollFactor;
}
protected void onOverScrolled(int scrollX, int scrollY, boolean clampedX, boolean clampedY) {
super.scrollTo(scrollX, scrollY);
}
boolean overScrollByCompat(int deltaX, int deltaY, int scrollX, int scrollY, int scrollRangeX, int scrollRangeY, int maxOverScrollX, int maxOverScrollY, boolean isTouchEvent) {
int overScrollMode = ViewCompat.getOverScrollMode(this);
boolean canScrollHorizontal = this.computeHorizontalScrollRange() > this.computeHorizontalScrollExtent();
boolean canScrollVertical = this.computeVerticalScrollRange() > this.computeVerticalScrollExtent();
boolean overScrollHorizontal = overScrollMode == 0 || overScrollMode == 1 && canScrollHorizontal;
boolean overScrollVertical = overScrollMode == 0 || overScrollMode == 1 && canScrollVertical;
int newScrollX = scrollX + deltaX;
if(!overScrollHorizontal) {
maxOverScrollX = 0;
}
int newScrollY = scrollY + deltaY;
if(!overScrollVertical) {
maxOverScrollY = 0;
}
int left = -maxOverScrollX;
int right = maxOverScrollX + scrollRangeX;
int top = -maxOverScrollY;
int bottom = maxOverScrollY + scrollRangeY;
boolean clampedX = false;
if(newScrollX > right) {
newScrollX = right;
clampedX = true;
} else if(newScrollX < left) {
newScrollX = left;
clampedX = true;
}
boolean clampedY = false;
if(newScrollY > bottom) {
newScrollY = bottom;
clampedY = true;
} else if(newScrollY < top) {
newScrollY = top;
clampedY = true;
}
this.onOverScrolled(newScrollX, newScrollY, clampedX, clampedY);
return clampedX || clampedY;
}
private int getScrollRange() {
int scrollRange = 0;
if(this.getChildCount() > 0) {
View child = this.getChildAt(0);
scrollRange = Math.max(0, child.getHeight() - (this.getHeight() - this.getPaddingBottom() - this.getPaddingTop()));
}
return scrollRange;
}
private View findFocusableViewInBounds(boolean topFocus, int top, int bottom) {
//noinspection ResourceType
ArrayList focusables = this.getFocusables(2);
View focusCandidate = null;
boolean foundFullyContainedFocusable = false;
int count = focusables.size();
for(int i = 0; i < count; ++i) {
View view = (View)focusables.get(i);
int viewTop = view.getTop();
int viewBottom = view.getBottom();
if(top < viewBottom && viewTop < bottom) {
boolean viewIsFullyContained = top < viewTop && viewBottom < bottom;
if(focusCandidate == null) {
focusCandidate = view;
foundFullyContainedFocusable = viewIsFullyContained;
} else {
boolean viewIsCloserToBoundary = topFocus && viewTop < focusCandidate.getTop() || !topFocus && viewBottom > focusCandidate.getBottom();
if(foundFullyContainedFocusable) {
if(viewIsFullyContained && viewIsCloserToBoundary) {
focusCandidate = view;
}
} else if(viewIsFullyContained) {
focusCandidate = view;
foundFullyContainedFocusable = true;
} else if(viewIsCloserToBoundary) {
focusCandidate = view;
}
}
}
}
return focusCandidate;
}
public boolean pageScroll(int direction) {
boolean down = direction == 130;
int height = this.getHeight();
if(down) {
this.mTempRect.top = this.getScrollY() + height;
int count = this.getChildCount();
if(count > 0) {
View view = this.getChildAt(count - 1);
if(this.mTempRect.top + height > view.getBottom()) {
this.mTempRect.top = view.getBottom() - height;
}
}
} else {
this.mTempRect.top = this.getScrollY() - height;
if(this.mTempRect.top < 0) {
this.mTempRect.top = 0;
}
}
this.mTempRect.bottom = this.mTempRect.top + height;
return this.scrollAndFocus(direction, this.mTempRect.top, this.mTempRect.bottom);
}
public boolean fullScroll(int direction) {
boolean down = direction == 130;
int height = this.getHeight();
this.mTempRect.top = 0;
this.mTempRect.bottom = height;
if(down) {
int count = this.getChildCount();
if(count > 0) {
View view = this.getChildAt(count - 1);
this.mTempRect.bottom = view.getBottom() + this.getPaddingBottom();
this.mTempRect.top = this.mTempRect.bottom - height;
}
}
return this.scrollAndFocus(direction, this.mTempRect.top, this.mTempRect.bottom);
}
private boolean scrollAndFocus(int direction, int top, int bottom) {
boolean handled = true;
int height = this.getHeight();
int containerTop = this.getScrollY();
int containerBottom = containerTop + height;
boolean up = direction == 33;
Object newFocused = this.findFocusableViewInBounds(up, top, bottom);
if(newFocused == null) {
newFocused = this;
}
if(top >= containerTop && bottom <= containerBottom) {
handled = false;
} else {
int delta = up?top - containerTop:bottom - containerBottom;
this.doScrollY(delta);
}
if(newFocused != this.findFocus()) {
((View)newFocused).requestFocus(direction);
}
return handled;
}
public boolean arrowScroll(int direction) {
View currentFocused = this.findFocus();
if(currentFocused == this) {
currentFocused = null;
}
View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused, direction);
int maxJump = this.getMaxScrollAmount();
int descendantFocusability;
if(nextFocused != null && this.isWithinDeltaOfScreen(nextFocused, maxJump, this.getHeight())) {
nextFocused.getDrawingRect(this.mTempRect);
this.offsetDescendantRectToMyCoords(nextFocused, this.mTempRect);
descendantFocusability = this.computeScrollDeltaToGetChildRectOnScreen(this.mTempRect);
this.doScrollY(descendantFocusability);
nextFocused.requestFocus(direction);
} else {
descendantFocusability = maxJump;
if(direction == 33 && this.getScrollY() < maxJump) {
descendantFocusability = this.getScrollY();
} else if(direction == 130 && this.getChildCount() > 0) {
int daBottom = this.getChildAt(0).getBottom();
int screenBottom = this.getScrollY() + this.getHeight() - this.getPaddingBottom();
if(daBottom - screenBottom < maxJump) {
descendantFocusability = daBottom - screenBottom;
}
}
if(descendantFocusability == 0) {
return false;
}
this.doScrollY(direction == 130?descendantFocusability:-descendantFocusability);
}
if(currentFocused != null && currentFocused.isFocused() && this.isOffScreen(currentFocused)) {
descendantFocusability = this.getDescendantFocusability();
//noinspection ResourceType
this.setDescendantFocusability(131072);
this.requestFocus();
this.setDescendantFocusability(descendantFocusability);
}
return true;
}
private boolean isOffScreen(View descendant) {
return !this.isWithinDeltaOfScreen(descendant, 0, this.getHeight());
}
private boolean isWithinDeltaOfScreen(View descendant, int delta, int height) {
descendant.getDrawingRect(this.mTempRect);
this.offsetDescendantRectToMyCoords(descendant, this.mTempRect);
return this.mTempRect.bottom + delta >= this.getScrollY() && this.mTempRect.top - delta <= this.getScrollY() + height;
}
private void doScrollY(int delta) {
if(delta != 0) {
if(this.mSmoothScrollingEnabled) {
this.smoothScrollBy(0, delta);
} else {
this.scrollBy(0, delta);
}
}
}
public final void smoothScrollBy(int dx, int dy) {
if(this.getChildCount() != 0) {
long duration = AnimationUtils.currentAnimationTimeMillis() - this.mLastScroll;
if(duration > 250L) {
int height = this.getHeight() - this.getPaddingBottom() - this.getPaddingTop();
int bottom = this.getChildAt(0).getHeight();
int maxY = Math.max(0, bottom - height);
int scrollY = this.getScrollY();
dy = Math.max(0, Math.min(scrollY + dy, maxY)) - scrollY;
this.mScroller.startScroll(this.getScrollX(), scrollY, 0, dy);
ViewCompat.postInvalidateOnAnimation(this);
} else {
if(!this.mScroller.isFinished()) {
this.mScroller.abortAnimation();
}
this.scrollBy(dx, dy);
}
this.mLastScroll = AnimationUtils.currentAnimationTimeMillis();
}
}
public final void smoothScrollTo(int x, int y) {
this.smoothScrollBy(x - this.getScrollX(), y - this.getScrollY());
}
protected int computeVerticalScrollRange() {
int count = this.getChildCount();
int contentHeight = this.getHeight() - this.getPaddingBottom() - this.getPaddingTop();
if(count == 0) {
return contentHeight;
} else {
int scrollRange = this.getChildAt(0).getBottom();
int scrollY = this.getScrollY();
int overscrollBottom = Math.max(0, scrollRange - contentHeight);
if(scrollY < 0) {
scrollRange -= scrollY;
} else if(scrollY > overscrollBottom) {
scrollRange += scrollY - overscrollBottom;
}
return scrollRange;
}
}
protected int computeVerticalScrollOffset() {
return Math.max(0, super.computeVerticalScrollOffset());
}
protected void measureChild(View child, int parentWidthMeasureSpec, int parentHeightMeasureSpec) {
LayoutParams lp = (LayoutParams) child.getLayoutParams();
int childWidthMeasureSpec = getChildMeasureSpec(parentWidthMeasureSpec, this.getPaddingLeft() + this.getPaddingRight(), lp.width);
//noinspection ResourceType
int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(0, 0);
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
protected void measureChildWithMargins(View child, int parentWidthMeasureSpec, int widthUsed, int parentHeightMeasureSpec, int heightUsed) {
MarginLayoutParams lp = (MarginLayoutParams)child.getLayoutParams();
int childWidthMeasureSpec = getChildMeasureSpec(parentWidthMeasureSpec, this.getPaddingLeft() + this.getPaddingRight() + lp.leftMargin + lp.rightMargin + widthUsed, lp.width);
//noinspection ResourceType
int childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(lp.topMargin + lp.bottomMargin, 0);
child.measure(childWidthMeasureSpec, childHeightMeasureSpec);
}
public void computeScroll() {
if(this.mScroller.computeScrollOffset()) {
int oldX = this.getScrollX();
int oldY = this.getScrollY();
int x = this.mScroller.getCurrX();
int y = this.mScroller.getCurrY();
if(oldX != x || oldY != y) {
int range = this.getScrollRange();
int overscrollMode = ViewCompat.getOverScrollMode(this);
boolean canOverscroll = overscrollMode == 0 || overscrollMode == 1 && range > 0;
this.overScrollByCompat(x - oldX, y - oldY, oldX, oldY, 0, range, 0, 0, false);
if(canOverscroll) {
this.ensureGlows();
if(y <= 0 && oldY > 0) {
this.mEdgeGlowTop.onAbsorb((int)this.mScroller.getCurrVelocity());
} else if(y >= range && oldY < range) {
this.mEdgeGlowBottom.onAbsorb((int)this.mScroller.getCurrVelocity());
}
}
}
}
}
private void scrollToChild(View child) {
child.getDrawingRect(this.mTempRect);
this.offsetDescendantRectToMyCoords(child, this.mTempRect);
int scrollDelta = this.computeScrollDeltaToGetChildRectOnScreen(this.mTempRect);
if(scrollDelta != 0) {
this.scrollBy(0, scrollDelta);
}
}
private boolean scrollToChildRect(Rect rect, boolean immediate) {
int delta = this.computeScrollDeltaToGetChildRectOnScreen(rect);
boolean scroll = delta != 0;
if(scroll) {
if(immediate) {
this.scrollBy(0, delta);
} else {
this.smoothScrollBy(0, delta);
}
}
return scroll;
}
protected int computeScrollDeltaToGetChildRectOnScreen(Rect rect) {
if(this.getChildCount() == 0) {
return 0;
} else {
int height = this.getHeight();
int screenTop = this.getScrollY();
int screenBottom = screenTop + height;
int fadingEdge = this.getVerticalFadingEdgeLength();
if(rect.top > 0) {
screenTop += fadingEdge;
}
if(rect.bottom < this.getChildAt(0).getHeight()) {
screenBottom -= fadingEdge;
}
int scrollYDelta = 0;
if(rect.bottom > screenBottom && rect.top > screenTop) {
if(rect.height() > height) {
scrollYDelta += rect.top - screenTop;
} else {
scrollYDelta += rect.bottom - screenBottom;
}
int bottom = this.getChildAt(0).getBottom();
int distanceToBottom = bottom - screenBottom;
scrollYDelta = Math.min(scrollYDelta, distanceToBottom);
} else if(rect.top < screenTop && rect.bottom < screenBottom) {
if(rect.height() > height) {
scrollYDelta -= screenBottom - rect.bottom;
} else {
scrollYDelta -= screenTop - rect.top;
}
scrollYDelta = Math.max(scrollYDelta, -this.getScrollY());
}
return scrollYDelta;
}
}
public void requestChildFocus(View child, View focused) {
if(!this.mIsLayoutDirty) {
this.scrollToChild(focused);
} else {
this.mChildToScrollTo = focused;
}
super.requestChildFocus(child, focused);
}
protected boolean onRequestFocusInDescendants(int direction, Rect previouslyFocusedRect) {
if(direction == 2) {
direction = 130;
} else if(direction == 1) {
direction = 33;
}
View nextFocus = previouslyFocusedRect == null?FocusFinder.getInstance().findNextFocus(this, null, direction):FocusFinder.getInstance().findNextFocusFromRect(this, previouslyFocusedRect, direction);
return nextFocus != null && (!this.isOffScreen(nextFocus) &&
nextFocus.requestFocus(direction, previouslyFocusedRect));
}
public boolean requestChildRectangleOnScreen(View child, Rect rectangle, boolean immediate) {
rectangle.offset(child.getLeft() - child.getScrollX(), child.getTop() - child.getScrollY());
return this.scrollToChildRect(rectangle, immediate);
}
public void requestLayout() {
this.mIsLayoutDirty = true;
super.requestLayout();
}
protected void onLayout(boolean changed, int l, int t, int r, int b) {
super.onLayout(changed, l, t, r, b);
this.mIsLayoutDirty = false;
if(this.mChildToScrollTo != null && isViewDescendantOf(this.mChildToScrollTo, this)) {
this.scrollToChild(this.mChildToScrollTo);
}
this.mChildToScrollTo = null;
if(!this.mIsLaidOut) {
if(this.mSavedState != null) {
this.scrollTo(this.getScrollX(), this.mSavedState.scrollPosition);
this.mSavedState = null;
}
int childHeight = this.getChildCount() > 0?this.getChildAt(0).getMeasuredHeight():0;
int scrollRange = Math.max(0, childHeight - (b - t - this.getPaddingBottom() - this.getPaddingTop()));
if(this.getScrollY() > scrollRange) {
this.scrollTo(this.getScrollX(), scrollRange);
} else if(this.getScrollY() < 0) {
this.scrollTo(this.getScrollX(), 0);
}
}
this.scrollTo(this.getScrollX(), this.getScrollY());
this.mIsLaidOut = true;
}
@SuppressLint("MissingSuperCall")
public void onAttachedToWindow() {
this.mIsLaidOut = false;
}
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
super.onSizeChanged(w, h, oldw, oldh);
View currentFocused = this.findFocus();
if(null != currentFocused && this != currentFocused) {
if(this.isWithinDeltaOfScreen(currentFocused, 0, oldh)) {
currentFocused.getDrawingRect(this.mTempRect);
this.offsetDescendantRectToMyCoords(currentFocused, this.mTempRect);
int scrollDelta = this.computeScrollDeltaToGetChildRectOnScreen(this.mTempRect);
this.doScrollY(scrollDelta);
}
}
}
private static boolean isViewDescendantOf(View child, View parent) {
if(child == parent) {
return true;
} else {
ViewParent theParent = child.getParent();
return theParent instanceof ViewGroup && isViewDescendantOf((View)theParent, parent);
}
}
/**
* Adjusted from AppCompat v23.0.0 so that the function returns true if the nested fling will
* end at the top of the scroll view. Which means that it should be dispatched to the
* CoordinatorLayout/AppBarLayout
* @param velocityY
* @return
*/
public boolean fling(int velocityY) {
if(this.getChildCount() > 0) {
int height = this.getHeight() - this.getPaddingBottom() - this.getPaddingTop();
int bottom = this.getChildAt(0).getHeight();
this.mScroller.fling(this.getScrollX(), this.getScrollY(), 0, velocityY, 0, 0, 0, Math.max(0, bottom - height), 0, height / 2);
ViewCompat.postInvalidateOnAnimation(this);
return mScroller.getFinalY() == 0;
}
return false;
}
private void flingWithNestedDispatch(int velocityY) {
int scrollY = this.getScrollY();
boolean canFling = (scrollY > 0 || velocityY > 0) && (scrollY < this.getScrollRange() || velocityY < 0);
if(!this.dispatchNestedPreFling(0.0F, (float)velocityY)) {
boolean dispatchFling = true;
if (canFling)
dispatchFling = fling(velocityY);
this.dispatchNestedFling(0.0F, (float)velocityY, !dispatchFling);
}
}
private void endDrag() {
this.mIsBeingDragged = false;
this.recycleVelocityTracker();
this.stopNestedScroll();
if(this.mEdgeGlowTop != null) {
this.mEdgeGlowTop.onRelease();
this.mEdgeGlowBottom.onRelease();
}
}
public void scrollTo(int x, int y) {
if(this.getChildCount() > 0) {
View child = this.getChildAt(0);
x = clamp(x, this.getWidth() - this.getPaddingRight() - this.getPaddingLeft(), child.getWidth());
y = clamp(y, this.getHeight() - this.getPaddingBottom() - this.getPaddingTop(), child.getHeight());
if(x != this.getScrollX() || y != this.getScrollY()) {
super.scrollTo(x, y);
}
}
}
private void ensureGlows() {
if(ViewCompat.getOverScrollMode(this) != 2) {
if(this.mEdgeGlowTop == null) {
Context context = this.getContext();
this.mEdgeGlowTop = new EdgeEffectCompat(context);
this.mEdgeGlowBottom = new EdgeEffectCompat(context);
}
} else {
this.mEdgeGlowTop = null;
this.mEdgeGlowBottom = null;
}
}
public void draw(Canvas canvas) {
super.draw(canvas);
if(this.mEdgeGlowTop != null) {
int scrollY = this.getScrollY();
int restoreCount;
int width;
if(!this.mEdgeGlowTop.isFinished()) {
restoreCount = canvas.save();
width = this.getWidth() - this.getPaddingLeft() - this.getPaddingRight();
canvas.translate((float)this.getPaddingLeft(), (float)Math.min(0, scrollY));
this.mEdgeGlowTop.setSize(width, this.getHeight());
if(this.mEdgeGlowTop.draw(canvas)) {
ViewCompat.postInvalidateOnAnimation(this);
}
canvas.restoreToCount(restoreCount);
}
if(!this.mEdgeGlowBottom.isFinished()) {
restoreCount = canvas.save();
width = this.getWidth() - this.getPaddingLeft() - this.getPaddingRight();
int height = this.getHeight();
canvas.translate((float)(-width + this.getPaddingLeft()), (float)(Math.max(this.getScrollRange(), scrollY) + height));
canvas.rotate(180.0F, (float)width, 0.0F);
this.mEdgeGlowBottom.setSize(width, height);
if(this.mEdgeGlowBottom.draw(canvas)) {
ViewCompat.postInvalidateOnAnimation(this);
}
canvas.restoreToCount(restoreCount);
}
}
}
private static int clamp(int n, int my, int child) {
return my < child && n >= 0?(my + n > child?child - my:n):0;
}
protected void onRestoreInstanceState(Parcelable state) {
FlingNestedScrollView.SavedState ss = (FlingNestedScrollView.SavedState)state;
super.onRestoreInstanceState(ss.getSuperState());
this.mSavedState = ss;
this.requestLayout();
}
protected Parcelable onSaveInstanceState() {
Parcelable superState = super.onSaveInstanceState();
FlingNestedScrollView.SavedState ss = new FlingNestedScrollView.SavedState(superState);
ss.scrollPosition = this.getScrollY();
return ss;
}
static class AccessibilityDelegate extends AccessibilityDelegateCompat {
AccessibilityDelegate() {
}
public boolean performAccessibilityAction(View host, int action, Bundle arguments) {
if(super.performAccessibilityAction(host, action, arguments)) {
return true;
} else {
FlingNestedScrollView nsvHost = (FlingNestedScrollView)host;
if(!nsvHost.isEnabled()) {
return false;
} else {
int viewportHeight;
int targetScrollY;
switch(action) {
case 4096:
viewportHeight = nsvHost.getHeight() - nsvHost.getPaddingBottom() - nsvHost.getPaddingTop();
targetScrollY = Math.min(nsvHost.getScrollY() + viewportHeight, nsvHost.getScrollRange());
if(targetScrollY != nsvHost.getScrollY()) {
nsvHost.smoothScrollTo(0, targetScrollY);
return true;
}
return false;
case 8192:
viewportHeight = nsvHost.getHeight() - nsvHost.getPaddingBottom() - nsvHost.getPaddingTop();
targetScrollY = Math.max(nsvHost.getScrollY() - viewportHeight, 0);
if(targetScrollY != nsvHost.getScrollY()) {
nsvHost.smoothScrollTo(0, targetScrollY);
return true;
}
return false;
default:
return false;
}
}
}
}
public void onInitializeAccessibilityNodeInfo(View host, AccessibilityNodeInfoCompat info) {
super.onInitializeAccessibilityNodeInfo(host, info);
FlingNestedScrollView nsvHost = (FlingNestedScrollView)host;
info.setClassName(ScrollView.class.getName());
if(nsvHost.isEnabled()) {
int scrollRange = nsvHost.getScrollRange();
if(scrollRange > 0) {
info.setScrollable(true);
if(nsvHost.getScrollY() > 0) {
info.addAction(8192);
}
if(nsvHost.getScrollY() < scrollRange) {
info.addAction(4096);
}
}
}
}
public void onInitializeAccessibilityEvent(View host, AccessibilityEvent event) {
super.onInitializeAccessibilityEvent(host, event);
FlingNestedScrollView nsvHost = (FlingNestedScrollView)host;
event.setClassName(ScrollView.class.getName());
AccessibilityRecordCompat record = AccessibilityEventCompat.asRecord(event);
boolean scrollable = nsvHost.getScrollRange() > 0;
record.setScrollable(scrollable);
record.setScrollX(nsvHost.getScrollX());
record.setScrollY(nsvHost.getScrollY());
record.setMaxScrollX(nsvHost.getScrollX());
record.setMaxScrollY(nsvHost.getScrollRange());
}
}
static class SavedState extends BaseSavedState {
public int scrollPosition;
public static final Creator<FlingNestedScrollView.SavedState> CREATOR = new Creator() {
public FlingNestedScrollView.SavedState createFromParcel(Parcel in) {
return new FlingNestedScrollView.SavedState(in);
}
public FlingNestedScrollView.SavedState[] newArray(int size) {
return new FlingNestedScrollView.SavedState[size];
}
};
SavedState(Parcelable superState) {
super(superState);
}
public SavedState(Parcel source) {
super(source);
this.scrollPosition = source.readInt();
}
public void writeToParcel(Parcel dest, int flags) {
super.writeToParcel(dest, flags);
dest.writeInt(this.scrollPosition);
}
public String toString() {
return "HorizontalScrollView.SavedState{" + Integer.toHexString(System.identityHashCode(this)) + " scrollPosition=" + this.scrollPosition + "}";
}
}
}