+package com.example.furt.myapplication;
+
+import android.content.Context;
+import android.graphics.Rect;
+import android.util.AttributeSet;
+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.animation.AnimationUtils;
+import android.widget.FrameLayout;
+import android.widget.Scroller;
+
+import java.util.List;
+
+
+/**
+ * Copyright (C) 2006 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.
+ *
+*
+ * Revised 5/19/2010 by GORGES
+ * Now supports two-dimensional view scrolling
+ * http://GORGES.us
+ */
+
+/**
+ * Layout container for a view hierarchy that can be scrolled by the user,
+ * allowing it to be larger than the physical display. A TwoDScrollView
+ * is a {@link android.widget.FrameLayout}, meaning you should place one child in it
+ * containing the entire contents to scroll; this child may itself be a layout
+ * manager with a complex hierarchy of objects. A child that is often used
+ * is a {@link android.widget.LinearLayout} in a vertical orientation, presenting a vertical
+ * array of top-level items that the user can scroll through.
+ *
+ * <p>The {@link android.widget.TextView} class also
+ * takes care of its own scrolling, so does not require a TwoDScrollView, but
+ * using the two together is possible to achieve the effect of a text view
+ * within a larger container.
+ */
+
+public class TwoDScrollView extends FrameLayout {
+ static final int ANIMATED_SCROLL_GAP = 250;
+ static final float MAX_SCROLL_FACTOR = 0.5f;
+
+ private long mLastScroll;
+
+ private final Rect mTempRect = new Rect();
+ private Scroller mScroller;
+
+ /*
+ * Flag to indicate that we are moving focus ourselves. This is so the
+ * code that watches for focus changes initiated outside this TwoDScrollView
+ * knows that it does not have to do anything.
+ */
+ private boolean mTwoDScrollViewMovedFocus;
+
+ /*
+ * Position of the last motion event.
+ */
+ private float mLastMotionY;
+ private float mLastMotionX;
+
+ /*
+ * 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;
+
+ /*
+ * True if the user is currently dragging this TwoDScrollView around. This is
+ * not the same as 'is being flinged', which can be checked by
+ * mScroller.isFinished() (flinging begins when the user lifts his finger).
+ */
+ private boolean mIsBeingDragged = false;
+
+ /*
+ * Determines speed during touch scrolling
+ */
+ private VelocityTracker mVelocityTracker;
+
+ /*
+ * Whether arrow scrolling is animated.
+ */
+ private int mTouchSlop;
+ private int mMinimumVelocity;
+ private int mMaximumVelocity;
+
+ public TwoDScrollView(Context context) {
+ super(context);
+ initTwoDScrollView();
+ }
+
+ public TwoDScrollView(Context context, AttributeSet attrs) {
+ super(context, attrs);
+ initTwoDScrollView();
+ }
+
+ public TwoDScrollView(Context context, AttributeSet attrs, int defStyle) {
+ super(context, attrs, defStyle);
+ initTwoDScrollView();
+ }
+
+ @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;
+ }
+
+ @Override
+ protected float getLeftFadingEdgeStrength() {
+ if (getChildCount() == 0) {
+ return 0.0f;
+ }
+ final int length = getHorizontalFadingEdgeLength();
+ if (getScrollX() < length) {
+ return getScrollX() / (float) length;
+ }
+ return 1.0f;
+ }
+
+ @Override
+ protected float getRightFadingEdgeStrength() {
+ if (getChildCount() == 0) {
+ return 0.0f;
+ }
+ final int length = getHorizontalFadingEdgeLength();
+ final int rightEdge = getWidth() - getPaddingRight();
+ final int span = getChildAt(0).getRight() - getScrollX() - rightEdge;
+ 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 getMaxScrollAmountVertical() {
+ return (int) (MAX_SCROLL_FACTOR * getHeight());
+ }
+ public int getMaxScrollAmountHorizontal() {
+ return (int) (MAX_SCROLL_FACTOR * getWidth());
+ }
+
+ private void initTwoDScrollView() {
+ mScroller = new Scroller(getContext());
+ setFocusable(true);
+ setDescendantFocusability(FOCUS_AFTER_DESCENDANTS);
+ setWillNotDraw(false);
+ final ViewConfiguration configuration = ViewConfiguration.get(getContext());
+ mTouchSlop = configuration.getScaledTouchSlop();
+ mMinimumVelocity = configuration.getScaledMinimumFlingVelocity();
+ mMaximumVelocity = configuration.getScaledMaximumFlingVelocity();
+ }
+
+ @Override
+ public void addView(View child) {
+ if (getChildCount() > 0) {
+ throw new IllegalStateException("TwoDScrollView can host only one direct child");
+ }
+ super.addView(child);
+ }
+
+ @Override
+ public void addView(View child, int index) {
+ if (getChildCount() > 0) {
+ throw new IllegalStateException("TwoDScrollView 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("TwoDScrollView 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("TwoDScrollView can host only one direct child");
+ }
+ super.addView(child, index, params);
+ }
+
+ /**
+ * @return Returns true this TwoDScrollView can be scrolled
+ */
+ private boolean canScroll() {
+ View child = getChildAt(0);
+ if (child != null) {
+ int childHeight = child.getHeight();
+ int childWidth = child.getWidth();
+ return (getHeight() < childHeight + getPaddingTop() + getPaddingBottom()) ||
+ (getWidth() < childWidth + getPaddingLeft() + getPaddingRight());
+ }
+ return false;
+ }
+
+ @Override
+ public boolean dispatchKeyEvent(KeyEvent event) {
+ // Let the focused view and/or our descendants get the key first
+ boolean handled = super.dispatchKeyEvent(event);
+ if (handled) {
+ return true;
+ }
+ return 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()) {
+ 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, false);
+ } else {
+ handled = fullScroll(View.FOCUS_UP, false);
+ }
+ break;
+ case KeyEvent.KEYCODE_DPAD_DOWN:
+ if (!event.isAltPressed()) {
+ handled = arrowScroll(View.FOCUS_DOWN, false);
+ } else {
+ handled = fullScroll(View.FOCUS_DOWN, false);
+ }
+ break;
+ case KeyEvent.KEYCODE_DPAD_LEFT:
+ if (!event.isAltPressed()) {
+ handled = arrowScroll(View.FOCUS_LEFT, true);
+ } else {
+ handled = fullScroll(View.FOCUS_LEFT, true);
+ }
+ break;
+ case KeyEvent.KEYCODE_DPAD_RIGHT:
+ if (!event.isAltPressed()) {
+ handled = arrowScroll(View.FOCUS_RIGHT, true);
+ } else {
+ handled = fullScroll(View.FOCUS_RIGHT, true);
+ }
+ break;
+ }
+ }
+ return handled;
+ }
+
+ @Override
+ public boolean onInterceptTouchEvent(MotionEvent ev) {
+ /*
+ * This method JUST determines whether we want to intercept the motion.
+ * If we return true, onMotionEvent will be called and we do the actual
+ * scrolling there.
+ *
+ * Shortcut the most recurring case: the user is in the dragging
+ * state and he is moving his finger. We want to intercept this
+ * motion.
+ */
+ final int action = ev.getAction();
+ if ((action == MotionEvent.ACTION_MOVE) && (mIsBeingDragged)) {
+ return true;
+ }
+ if (!canScroll()) {
+ mIsBeingDragged = false;
+ return false;
+ }
+ final float y = ev.getY();
+ final float x = ev.getX();
+ switch (action) {
+ case MotionEvent.ACTION_MOVE:
+ /*
+ * mIsBeingDragged == false, otherwise the shortcut would have caught it. Check
+ * whether the user has moved far enough from his original down touch.
+ */
+ /*
+ * Locally do absolute value. mLastMotionY is set to the y value
+ * of the down event.
+ */
+ final int yDiff = (int) Math.abs(y - mLastMotionY);
+ final int xDiff = (int) Math.abs(x - mLastMotionX);
+ if (yDiff > mTouchSlop || xDiff > mTouchSlop) {
+ mIsBeingDragged = true;
+ }
+ break;
+
+ case MotionEvent.ACTION_DOWN:
+ /* Remember location of down touch */
+ mLastMotionY = y;
+ mLastMotionX = x;
+
+ /*
+ * If being flinged and user touches the screen, initiate drag;
+ * otherwise don't. mScroller.isFinished should be false when
+ * being flinged.
+ */
+ mIsBeingDragged = !mScroller.isFinished();
+ break;
+
+ case MotionEvent.ACTION_CANCEL:
+ case MotionEvent.ACTION_UP:
+ /* Release the drag */
+ mIsBeingDragged = false;
+ break;
+ }
+
+ /*
+ * The only time we want to intercept motion events is if we are in the
+ * drag mode.
+ */
+ return mIsBeingDragged;
+ }
+
+ @Override
+ public boolean onTouchEvent(MotionEvent ev) {
+
+ if (ev.getAction() == MotionEvent.ACTION_DOWN && ev.getEdgeFlags() != 0) {
+ // Don't handle edge touches immediately -- they may actually belong to one of our
+ // descendants.
+ return false;
+ }
+
+ if (!canScroll()) {
+ return false;
+ }
+
+ if (mVelocityTracker == null) {
+ mVelocityTracker = VelocityTracker.obtain();
+ }
+ mVelocityTracker.addMovement(ev);
+
+ final int action = ev.getAction();
+ final float y = ev.getY();
+ final float x = ev.getX();
+
+ switch (action) {
+ case MotionEvent.ACTION_DOWN:
+ /*
+ * If being flinged and user touches, stop the fling. isFinished
+ * will be false if being flinged.
+ */
+ if (!mScroller.isFinished()) {
+ mScroller.abortAnimation();
+ }
+
+ // Remember where the motion event started
+ mLastMotionY = y;
+ mLastMotionX = x;
+ break;
+ case MotionEvent.ACTION_MOVE:
+ // Scroll to follow the motion event
+ int deltaX = (int) (mLastMotionX - x);
+ int deltaY = (int) (mLastMotionY - y);
+ mLastMotionX = x;
+ mLastMotionY = y;
+
+ if (deltaX < 0) {
+ if (getScrollX() < 0) {
+ deltaX = 0;
+ }
+ } else if (deltaX > 0) {
+ final int rightEdge = getWidth() - getPaddingRight();
+ final int availableToScroll = getChildAt(0).getRight() - getScrollX() - rightEdge;
+ if (availableToScroll > 0) {
+ deltaX = Math.min(availableToScroll, deltaX);
+ } else {
+ deltaX = 0;
+ }
+ }
+ if (deltaY < 0) {
+ if (getScrollY() < 0) {
+ deltaY = 0;
+ }
+ } else if (deltaY > 0) {
+ final int bottomEdge = getHeight() - getPaddingBottom();
+ final int availableToScroll = getChildAt(0).getBottom() - getScrollY() - bottomEdge;
+ if (availableToScroll > 0) {
+ deltaY = Math.min(availableToScroll, deltaY);
+ } else {
+ deltaY = 0;
+ }
+ }
+ if (deltaY != 0 || deltaX != 0)
+ scrollBy(deltaX, deltaY);
+ break;
+ case MotionEvent.ACTION_UP:
+ final VelocityTracker velocityTracker = mVelocityTracker;
+ velocityTracker.computeCurrentVelocity(1000, mMaximumVelocity);
+ int initialXVelocity = (int) velocityTracker.getXVelocity();
+ int initialYVelocity = (int) velocityTracker.getYVelocity();
+ if ((Math.abs(initialXVelocity) + Math.abs(initialYVelocity) > mMinimumVelocity) && getChildCount() > 0) {
+ fling(-initialXVelocity, -initialYVelocity);
+ }
+ if (mVelocityTracker != null) {
+ mVelocityTracker.recycle();
+ mVelocityTracker = null;
+ }
+ }
+ return true;
+ }
+
+ /**
+ * Finds the next focusable component that fits in this View's bounds
+ * (excluding fading edges) pretending that this View's top is located at
+ * the parameter top.
+ *
+ * @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 (the fading edge is assumed to start at this position)
+ * @param preferredFocusable the View that has highest priority and will be
+ * returned if it is within my bounds (null is valid)
+ * @return the next focusable component in the bounds or null if none can be
+ * found
+ */
+ private View findFocusableViewInMyBounds(final boolean topFocus, final int top, final boolean leftFocus, final int left, View preferredFocusable) {
+ /*
+ * The fading edge's transparent side should be considered for focus
+ * since it's mostly visible, so we divide the actual fading edge length
+ * by 2.
+ */
+ final int verticalFadingEdgeLength = getVerticalFadingEdgeLength() / 2;
+ final int topWithoutFadingEdge = top + verticalFadingEdgeLength;
+ final int bottomWithoutFadingEdge = top + getHeight() - verticalFadingEdgeLength;
+ final int horizontalFadingEdgeLength = getHorizontalFadingEdgeLength() / 2;
+ final int leftWithoutFadingEdge = left + horizontalFadingEdgeLength;
+ final int rightWithoutFadingEdge = left + getWidth() - horizontalFadingEdgeLength;
+
+ if ((preferredFocusable != null)
+ && (preferredFocusable.getTop() < bottomWithoutFadingEdge)
+ && (preferredFocusable.getBottom() > topWithoutFadingEdge)
+ && (preferredFocusable.getLeft() < rightWithoutFadingEdge)
+ && (preferredFocusable.getRight() > leftWithoutFadingEdge)) {
+ return preferredFocusable;
+ }
+ return findFocusableViewInBounds(topFocus, topWithoutFadingEdge, bottomWithoutFadingEdge, leftFocus, leftWithoutFadingEdge, rightWithoutFadingEdge);
+ }
+
+ /**
+ * 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, boolean leftFocus, int left, int right) {
+ 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();
+ int viewLeft = view.getLeft();
+ int viewRight = view.getRight();
+
+ if (top < viewBottom && viewTop < bottom && left < viewRight && viewLeft < right) {
+ /*
+ * the focusable is in the target area, it is a candidate for
+ * focusing
+ */
+ final boolean viewIsFullyContained = (top < viewTop) && (viewBottom < bottom) && (left < viewLeft) && (viewRight < right);
+ if (focusCandidate == null) {
+ /* No candidate, take this one */
+ focusCandidate = view;
+ foundFullyContainedFocusable = viewIsFullyContained;
+ } else {
+ final boolean viewIsCloserToVerticalBoundary =
+ (topFocus && viewTop < focusCandidate.getTop()) ||
+ (!topFocus && viewBottom > focusCandidate.getBottom());
+ final boolean viewIsCloserToHorizontalBoundary =
+ (leftFocus && viewLeft < focusCandidate.getLeft()) ||
+ (!leftFocus && viewRight > focusCandidate.getRight());
+ if (foundFullyContainedFocusable) {
+ if (viewIsFullyContained && viewIsCloserToVerticalBoundary && viewIsCloserToHorizontalBoundary) {
+ /*
+ * 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 (viewIsCloserToVerticalBoundary && viewIsCloserToHorizontalBoundary) {
+ /*
+ * Partially contained view beats another partially
+ * contained view if it's closer
+ */
+ focusCandidate = view;
+ }
+ }
+ }
+ }
+ }
+ return focusCandidate;
+ }
+
+ /**
+ * <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 horizontal) {
+ if (!horizontal) {
+ 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();
+ mTempRect.top = mTempRect.bottom - height;
+ }
+ }
+ return scrollAndFocus(direction, mTempRect.top, mTempRect.bottom, 0, 0, 0);
+ } else {
+ boolean right = direction == View.FOCUS_DOWN;
+ int width = getWidth();
+ mTempRect.left = 0;
+ mTempRect.right = width;
+ if (right) {
+ int count = getChildCount();
+ if (count > 0) {
+ View view = getChildAt(count - 1);
+ mTempRect.right = view.getBottom();
+ mTempRect.left = mTempRect.right - width;
+ }
+ }
+ return scrollAndFocus(0, 0, 0, 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 directionY, int top, int bottom, int directionX, int left, int right) {
+ boolean handled = true;
+ int height = getHeight();
+ int containerTop = getScrollY();
+ int containerBottom = containerTop + height;
+ boolean up = directionY == View.FOCUS_UP;
+ int width = getWidth();
+ int containerLeft = getScrollX();
+ int containerRight = containerLeft + width;
+ boolean leftwards = directionX == View.FOCUS_UP;
+ View newFocused = findFocusableViewInBounds(up, top, bottom, leftwards, left, right);
+ if (newFocused == null) {
+ newFocused = this;
+ }
+ if ((top >= containerTop && bottom <= containerBottom) || (left >= containerLeft && right <= containerRight)) {
+ handled = false;
+ } else {
+ int deltaY = up ? (top - containerTop) : (bottom - containerBottom);
+ int deltaX = leftwards ? (left - containerLeft) : (right - containerRight);
+ doScroll(deltaX, deltaY);
+ }
+ if (newFocused != findFocus() && newFocused.requestFocus(directionY)) {
+ mTwoDScrollViewMovedFocus = true;
+ mTwoDScrollViewMovedFocus = false;
+ }
+ 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
+ */
+ public boolean arrowScroll(int direction, boolean horizontal) {
+ View currentFocused = findFocus();
+ if (currentFocused == this) currentFocused = null;
+ View nextFocused = FocusFinder.getInstance().findNextFocus(this, currentFocused, direction);
+ final int maxJump = horizontal ? getMaxScrollAmountHorizontal() : getMaxScrollAmountVertical();
+
+ if (!horizontal) {
+ if (nextFocused != null) {
+ nextFocused.getDrawingRect(mTempRect);
+ offsetDescendantRectToMyCoords(nextFocused, mTempRect);
+ int scrollDelta = computeScrollDeltaToGetChildRectOnScreen(mTempRect);
+ doScroll(0, 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();
+ if (daBottom - screenBottom < maxJump) {
+ scrollDelta = daBottom - screenBottom;
+ }
+ }
+ }
+ if (scrollDelta == 0) {
+ return false;
+ }
+ doScroll(0, direction == View.FOCUS_DOWN ? scrollDelta : -scrollDelta);
+ }
+ } else {
+ if (nextFocused != null) {
+ nextFocused.getDrawingRect(mTempRect);
+ offsetDescendantRectToMyCoords(nextFocused, mTempRect);
+ int scrollDelta = computeScrollDeltaToGetChildRectOnScreen(mTempRect);
+ doScroll(scrollDelta, 0);
+ 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();
+ if (daBottom - screenBottom < maxJump) {
+ scrollDelta = daBottom - screenBottom;
+ }
+ }
+ }
+ if (scrollDelta == 0) {
+ return false;
+ }
+ doScroll(direction == View.FOCUS_DOWN ? scrollDelta : -scrollDelta, 0);
+ }
+ }
+ return true;
+ }
+
+ /**
+ * Smooth scroll by a Y delta
+ *
+ * @param delta the number of pixels to scroll by on the Y axis
+ */
+ private void doScroll(int deltaX, int deltaY) {
+ if (deltaX != 0 || deltaY != 0) {
+ smoothScrollBy(deltaX, deltaY);
+ }
+ }
+
+ /**
+ * Like {@link android.view.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) {
+ long duration = AnimationUtils.currentAnimationTimeMillis() - mLastScroll;
+ if (duration > ANIMATED_SCROLL_GAP) {
+ mScroller.startScroll(getScrollX(), getScrollY(), dx, dy);
+ awakenScrollBars(mScroller.getDuration());
+ invalidate();
+ } else {
+ if (!mScroller.isFinished()) {
+ mScroller.abortAnimation();
+ }
+ scrollBy(dx, dy);
+ }
+ mLastScroll = AnimationUtils.currentAnimationTimeMillis();
+ }
+
+ /**
+ * 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() {
+ int count = getChildCount();
+ return count == 0 ? getHeight() : (getChildAt(0)).getBottom();
+ }
+ @Override
+ protected int computeHorizontalScrollRange() {
+ int count = getChildCount();
+ return count == 0 ? getWidth() : (getChildAt(0)).getRight();
+ }
+
+ @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()) {
+ // This is called at drawing time by ViewGroup. We don't want to
+ // re-show the scrollbars at this point, which scrollTo will do,
+ // so we replicate most of scrollTo here.
+ //
+ // It's a little odd to call onScrollChanged from inside the drawing.
+ //
+ // It is, except when you remember that computeScroll() is used to
+ // animate scrolling. So unless we want to defer the onScrollChanged()
+ // until the end of the animated scrolling, we don't really have a
+ // choice here.
+ //
+ // I agree. The alternative, which I think would be worse, is to post
+ // something and tell the subclasses later. This is bad because there
+ // will be a window where mScrollX/Y is different from what the app
+ // thinks it is.
+ //
+ int oldX = getScrollX();
+ int oldY = getScrollY();
+ int x = mScroller.getCurrX();
+ int y = mScroller.getCurrY();
+ if (getChildCount() > 0) {
+ View child = getChildAt(0);
+ scrollTo(clamp(x, getWidth() - getPaddingRight() - getPaddingLeft(), child.getWidth()),
+ clamp(y, getHeight() - getPaddingBottom() - getPaddingTop(), child.getHeight()));
+ } else {
+ scrollTo(x, y);
+ }
+ if (oldX != getScrollX() || oldY != getScrollY()) {
+ onScrollChanged(getScrollX(), getScrollY(), oldX, oldY);
+ }
+
+ // Keep on drawing until the animation has finished.
+ postInvalidate();
+ }
+ }
+
+ /**
+ * 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 TwoDScrollView 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 (!mTwoDScrollViewMovedFocus) {
+ 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.
+ *
+ * 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;
+ }
+
+ 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 onLayout(boolean changed, int l, int t, int r, int b) {
+ super.onLayout(changed, l, t, r, b);
+ mIsLayoutDirty = false;
+ // Give a child focus if it needs it
+ if (mChildToScrollTo != null && isViewDescendantOf(mChildToScrollTo, this)) {
+ scrollToChild(mChildToScrollTo);
+ }
+ mChildToScrollTo = null;
+
+ // Calling this with the present values causes it to re-clam 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.
+ currentFocused.getDrawingRect(mTempRect);
+ offsetDescendantRectToMyCoords(currentFocused, mTempRect);
+ int scrollDeltaX = computeScrollDeltaToGetChildRectOnScreen(mTempRect);
+ int scrollDeltaY = computeScrollDeltaToGetChildRectOnScreen(mTempRect);
+ doScroll(scrollDeltaX, scrollDeltaY);
+ }
+
+ /**
+ * Return true if child is an descendant of parent, (or equal to the parent).
+ */
+ private 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/curor is moving down the screen,
+ * which means we want to scroll towards the top.
+ */
+ public void fling(int velocityX, int velocityY) {
+ if (getChildCount() > 0) {
+ int height = getHeight() - getPaddingBottom() - getPaddingTop();
+ int bottom = getChildAt(0).getHeight();
+ int width = getWidth() - getPaddingRight() - getPaddingLeft();
+ int right = getChildAt(0).getWidth();
+
+ mScroller.fling(getScrollX(), getScrollY(), velocityX, velocityY, 0, right - width, 0, bottom - height);
+
+ final boolean movingDown = velocityY > 0;
+ final boolean movingRight = velocityX > 0;
+
+ View newFocused = findFocusableViewInMyBounds(movingRight, mScroller.getFinalX(), movingDown, mScroller.getFinalY(), findFocus());
+ if (newFocused == null) {
+ newFocused = this;
+ }
+
+ if (newFocused != findFocus() && newFocused.requestFocus(movingDown ? View.FOCUS_DOWN : View.FOCUS_UP)) {
+ mTwoDScrollViewMovedFocus = true;
+ mTwoDScrollViewMovedFocus = false;
+ }
+
+ awakenScrollBars(mScroller.getDuration());
+ invalidate();
+ }
+ }
+
+ /**
+ * {@inheritDoc}
+ *
+ * <p>This version also clamps the scrolling to the bounds of our child.
+ */
+ 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);
+ }
+ }
+ }
+
+ private 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;
+ }
+}