Move client/{base, observable, layout, touch, util, view} to samples/ui_lib .

client/touch/Scroller.dart

Index: client/touch/Scroller.dart
===================================================================
--- client/touch/Scroller.dart	(revision 4144)
+++ client/touch/Scroller.dart	(working copy)
@@ -1,731 +0,0 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-/**
- * Implementation of a custom scrolling behavior.
- * This behavior overrides native scrolling for an area. This area can be a
- * single defined part of a page, the entire page, or several different parts
- * of a page.
- *
- * To use this scrolling behavior you need to define a frame and the content.
- * The frame defines the area that the content will scroll within. The frame and
- * content must both be HTML Elements, with the content being a direct child of
- * the frame. Usually the frame is smaller in size than the content. This is
- * not necessary though, if the content is smaller then bouncing will occur to
- * provide feedback that you are past the scrollable area.
- *
- * The scrolling behavior works using the webkit translate3d transformation,
- * which means browsers that do not have hardware accelerated transformations
- * will not perform as well using this. Simple scrolling should be fine even
- * without hardware acceleration, but animating momentum and deceleration is
- * unacceptably slow without it. There is also the option to use relative
- * positioning (setting the left and top styles).
- *
- * For this to work properly you need to set -webkit-text-size-adjust to 'none'
- * on an ancestor element of the frame, or on the frame itself. If you forget
- * this you may see the text content of the scrollable area changing size as it
- * moves.
- *
- * The behavior is intended to support vertical and horizontal scrolling, and
- * scrolling with momentum when a touch gesture flicks with enough velocity.
- */
-typedef void Callback();
-
-// Helper method to await the completion of 2 futures.
-void joinFutures(List<Future> futures, Callback callback) {
-  int count = 0;
-  int len = futures.length;
-  void helper(value) {
-    count++;
-    if (count == len) {
-      callback();
-    }
-  }
-  for (Future p in futures) {
-    p.then(helper);
-  }
-}
-
-class Scroller implements Draggable, MomentumDelegate {
-
-  /** Pixels to move each time an arrow key is pressed. */
-  static final ARROW_KEY_DELTA = 30;
-  static final SCROLL_WHEEL_VELOCITY = 0.01;
-  static final FAST_SNAP_DECELERATION_FACTOR = 0.84;
-  static final PAGE_KEY_SCROLL_FRACTION = .85;
-
-  // TODO(jacobr): remove this static variable.
-  static bool _dragInProgress = false;
-
-  /** The node that will actually scroll. */
-  Element _element;
-
-  /**
-   * Frame is the node that will serve as the container for the scrolling
-   * content.
-   */
-  Element _frame;
-
-  /** Touch manager to track the events on the scrollable area. */
-  TouchHandler _touchHandler;
-
-  Momentum _momentum;
-
-  EventListenerList _onScrollerStart;
-  EventListenerList _onScrollerEnd;
-  EventListenerList _onScrollerDragEnd;
-  EventListenerList _onContentMoved;
-  EventListenerList _onDecelStart;
-
-  /** Set if vertical scrolling should be enabled. */
-  bool verticalEnabled;
-
-  /** Set if horizontal scrolling should be enabled. */
-  bool horizontalEnabled;
-
-  /**
-   * Set if momentum should be enabled.
-   */
-  bool _momentumEnabled;
-
-  /** Set which type of scrolling translation technique should be used. */
-  int _scrollTechnique;
-
-  /**
-   * The maximum coordinate that the left upper corner of the content can scroll
-   * to.
-   */
-  Coordinate _maxPoint;
-
-  /**
-   * An offset to subtract from the maximum coordinate that the left upper
-   * corner of the content can scroll to.
-   */
-  Coordinate _maxOffset;
-
-  /**
-   * An offset to add to the minimum coordinate that the left upper corner of
-   * the content can scroll to.
-   */
-  Coordinate _minOffset;
-
-  /** Initialize the current content offset. */
-  Coordinate _contentOffset;
-
-  // TODO(jacobr): the function type is
-  // [:Function(Element, num, num)->void:].
-  /**
-   * The function to use that will actually translate the scrollable node.
-   */
-  Function _setOffsetFunction;
-  /**
-   * Function that returns the content size that can be specified instead of
-   * querying the DOM.
-   */
-  Function _lookupContentSizeDelegate;
-
-  Size _scrollSize;
-  Size _contentSize;
-  Coordinate _minPoint;
-  bool _isStopping = false;
-  Coordinate _contentStartOffset;
-  bool _started = false;
-  bool _activeGesture = false;
-  ScrollWatcher _scrollWatcher;
-
-  Scroller(Element scrollableElem, [this.verticalEnabled = false,
-           this.horizontalEnabled = false,
-           momentumEnabled = true,
-           lookupContentSizeDelegate = null,
-           num defaultDecelerationFactor = 1,
-           int scrollTechnique = null, bool capture = false])
-      : _momentumEnabled = momentumEnabled,
-        _lookupContentSizeDelegate = lookupContentSizeDelegate,
-        _element = scrollableElem,
-        _frame = scrollableElem.parent,
-        _scrollTechnique = scrollTechnique !== null
-            ? scrollTechnique : ScrollerScrollTechnique.TRANSFORM_3D,
-        _minPoint = new Coordinate(0, 0),
-        _maxPoint = new Coordinate(0, 0),
-        _maxOffset = new Coordinate(0, 0),
-        _minOffset = new Coordinate(0, 0),
-        _contentOffset = new Coordinate(0, 0) {
-    _touchHandler = new TouchHandler(this, scrollableElem.parent);
-    _momentum = new Momentum(this, defaultDecelerationFactor);
-
-    Element parentElem = scrollableElem.parent;
-    assert(parentElem != null);
-    _setOffsetFunction = _getOffsetFunction(_scrollTechnique);
-    _touchHandler.setDraggable(this);
-    _touchHandler.enable(capture);
-
-    _frame.on.mouseWheel.add((e) {
-      if (e.wheelDeltaY != 0 && verticalEnabled ||
-          e.wheelDeltaX != 0 && horizontalEnabled) {
-        num x = horizontalEnabled ? e.wheelDeltaX : 0;
-        num y = verticalEnabled ? e.wheelDeltaY : 0;
-        throwDelta(x, y, FAST_SNAP_DECELERATION_FACTOR);
-        e.preventDefault();
-      }
-    });
-
-    _frame.on.keyDown.add((KeyboardEvent e) {
-        bool handled = false;
-        // We ignore key events where further scrolling in that direction
-        // would have no impact which matches default browser behavior with
-        // nested scrollable areas.
-
-        switch(e.keyCode) {
-          case 33: // page-up
-            throwDelta(
-                0,
-                _scrollSize.height * PAGE_KEY_SCROLL_FRACTION);
-            handled = true;
-            break;
-          case 34: // page-down
-            throwDelta(
-                0, -_scrollSize.height * PAGE_KEY_SCROLL_FRACTION);
-            handled = true;
-            break;
-          case 35: // End
-             throwTo(_maxPoint.x, _minPoint.y,
-                FAST_SNAP_DECELERATION_FACTOR);
-            handled = true;
-            break;
-          case 36: // Home
-            throwTo(_maxPoint.x,_maxPoint.y,
-                FAST_SNAP_DECELERATION_FACTOR);
-            handled = true;
-            break;
-/* TODO(jacobr): enable arrow keys when the don't conflict with other
-   application keyboard shortcuts.
-          case 38: // up
-            handled = throwDelta(
-                0,
-                ARROW_KEY_DELTA,
-                FAST_SNAP_DECELERATION_FACTOR);
-            break;
-          case 40: // down
-            handled = throwDelta(
-                0, -ARROW_KEY_DELTA,
-                FAST_SNAP_DECELERATION_FACTOR);
-            break;
-          case 37: // left
-            handled = throwDelta(
-                ARROW_KEY_DELTA, 0,
-                FAST_SNAP_DECELERATION_FACTOR);
-            break;
-          case 39: // right
-            handled = throwDelta(
-                -ARROW_KEY_DELTA,
-                0,
-                FAST_SNAP_DECELERATION_FACTOR);
-            break;
-            */
-        }
-        if (handled) {
-          e.preventDefault();
-        }
-      });
-    // The scrollable element must be relatively positioned.
-    // TODO(jacobr): this assert fires asynchronously which could be confusing.
-    if (_scrollTechnique == ScrollerScrollTechnique.RELATIVE_POSITIONING) {
-      _element.computedStyle.then((CSSStyleDeclaration style) {
-        assert(style.position != "static");
-      });
-    }
-
-    _initLayer();
-  }
-
-  EventListenerList get onScrollerStart() {
-    if (_onScrollerStart === null) {
-      _onScrollerStart = new SimpleEventListenerList();
-    }
-    return _onScrollerStart;
-  }
-
-  EventListenerList get onScrollerEnd() {
-    if (_onScrollerEnd === null) {
-      _onScrollerEnd = new SimpleEventListenerList();
-    }
-    return _onScrollerEnd;
-  }
-
-  EventListenerList get onScrollerDragEnd() {
-    if (_onScrollerDragEnd === null) {
-      _onScrollerDragEnd = new SimpleEventListenerList();
-    }
-    return _onScrollerDragEnd;
-  }
-
-  EventListenerList get onContentMoved() {
-    if (_onContentMoved === null) {
-      _onContentMoved = new SimpleEventListenerList();
-    }
-    return _onContentMoved;
-  }
-
-  EventListenerList get onDecelStart() {
-    if (_onDecelStart === null) {
-      _onDecelStart = new SimpleEventListenerList();
-    }
-    return _onDecelStart;
-  }
-
-
-  /**
-   * Add a scroll listener. This allows other classes to subscribe to scroll
-   * notifications from this scroller.
-   */
-  void addScrollListener(ScrollListener listener) {
-    if (_scrollWatcher === null) {
-      _scrollWatcher = new ScrollWatcher(this);
-      _scrollWatcher.initialize();
-    }
-    _scrollWatcher.addListener(listener);
-  }
-
-  /**
-   * Adjust the new calculated scroll position based on the minimum allowed
-   * position and returns the adjusted scroll value.
-   */
-  num _adjustValue(num newPosition, num minPosition,
-                      num maxPosition) {
-    assert(minPosition <= maxPosition);
-
-    if (newPosition < minPosition) {
-      newPosition -= (newPosition - minPosition) / 2;
-    } else {
-      if (newPosition > maxPosition) {
-        newPosition -= (newPosition - maxPosition) / 2;
-      }
-    }
-    return newPosition;
-  }
-
-  /**
-   * Coordinate we would end up at if we did nothing.
-   */
-  Coordinate get currentTarget() {
-    Coordinate end = _momentum.destination;
-    if (end === null) {
-      end = _contentOffset;
-    }
-    return end;
-  }
-
-  Coordinate get contentOffset() => _contentOffset;
-
-  /**
-   * Animate the position of the scroller to the specified [x], [y] coordinates
-   * by applying the throw gesture with the correct velocity to end at that
-   * location.
-   */
-  void throwTo(num x, num y, [num decelerationFactor = null]) {
-    reconfigure(() {
-      final snappedTarget = _snapToBounds(x, y);
-      // If a deceleration factor is not specified, use the existing
-      // deceleration factor specified by the momentum simulator.
-      if (decelerationFactor == null) {
-        decelerationFactor = _momentum.decelerationFactor;
-      }
-
-      if (snappedTarget != currentTarget) {
-        _momentum.abort();
-
-        _startDeceleration(
-            _momentum.calculateVelocity(
-                _contentOffset,
-                snappedTarget,
-                decelerationFactor),
-            decelerationFactor);
-        onDecelStart.dispatch(new Event(ScrollerEventType.DECEL_START));
-      }
-    });
-  }
-
-  void throwDelta(num deltaX, num deltaY, [num decelerationFactor = null]) {
-    Coordinate start = _contentOffset;
-    Coordinate end = currentTarget;
-    int x = end.x.toInt();
-    int y = end.y.toInt();
-    // If we are throwing in the opposite direction of the existing momentum,
-    // cancel the current momentum.
-    if (deltaX != 0 && deltaX.isNegative() != (end.x - start.x).isNegative()) {
-      x = start.x;
-    }
-    if (deltaY != 0 && deltaY.isNegative() != (end.y - start.y).isNegative()) {
-      y = start.y;
-    }
-    x += deltaX.toInt();
-    y += deltaY.toInt();
-    throwTo(x, y, decelerationFactor);
-  }
-
-  void setPosition(num x, num y) {
-    _momentum.abort();
-    _contentOffset.x = x;
-    _contentOffset.y = y;
-    _snapContentOffsetToBounds();
-    _setContentOffset(_contentOffset.x, _contentOffset.y);
-  }
-  /**
-   * Adjusted content size is a size with the combined largest height and width
-   * of both the content and the frame.
-   */
-  Size _getAdjustedContentSize() {
-    return new Size(Math.max(_scrollSize.width, _contentSize.width),
-                    Math.max(_scrollSize.height, _contentSize.height));
-  }
-
-  // TODO(jmesserly): these should be properties instead of get* methods
-  num getDefaultVerticalOffset() =>  _maxPoint.y;
-  Element getElement() => _element;
-  Element getFrame() => _frame;
-  num getHorizontalOffset() => _contentOffset.x;
-
-  /**
-   * [x] Value to use as reference for percent measurement. If
-   *      none is provided then the content's current x offset will be used.
-   * Returns the percent of the page scrolled horizontally.
-   */
-  num getHorizontalScrollPercent([num x = null]) {
-    x = x !== null ? x : _contentOffset.x;
-    return (x - _minPoint.x) / (_maxPoint.x - _minPoint.x);
-  }
-
-  num getMaxPointY()=> _maxPoint.y;
-  num getMinPointY() => _minPoint.y;
-  Momentum get momentum() => _momentum;
-
-  /**
-   * Provide access to the touch handler that the scroller created to manage
-   * touch events.
-   */
-  TouchHandler getTouchHandler() => _touchHandler;
-  num getVerticalOffset() => _contentOffset.y;
-
-  /**
-   * [y] value is used as reference for percent measurement. If
-   * none is provided then the content's current y offset will be used.
-   */
-  num getVerticalScrollPercent([num y = null]) {
-    y = y !== null ? y : _contentOffset.y;
-    return (y - _minPoint.y) / Math.max(1, _maxPoint.y - _minPoint.y);
-  }
-
-  /**
-   * Initialize the dom elements necessary for the scrolling to work.
-   */
-  void _initLayer() {
-    // The scrollable node provided to Scroller must be a direct child
-    // of the scrollable frame.
-    // TODO(jacobr): Figure out why this is failing on dartium.
-    // assert(_element.parent == _frame);
-    _setContentOffset(_maxPoint.x, _maxPoint.y);
-  }
-
-  void onDecelerate(num x, num y) {
-    _setContentOffset(x, y);
-  }
-
-  void onDecelerationEnd() {
-    onScrollerEnd.dispatch(new Event(ScrollerEventType.SCROLLER_END));
-    _started = false;
-  }
-
-  void onDragEnd() {
-    _dragInProgress = false;
-
-    bool decelerating = false;
-    if (_activeGesture) {
-      if (_momentumEnabled) {
-        decelerating = _startDeceleration(_touchHandler.getEndVelocity());
-      }
-    }
-
-    onScrollerDragEnd.dispatch(new Event(ScrollerEventType.DRAG_END));
-
-    if (!decelerating) {
-      _snapContentOffsetToBounds();
-      onScrollerEnd.dispatch(new Event(ScrollerEventType.SCROLLER_END));
-      _started = false;
-    } else {
-      onDecelStart.dispatch(new Event(ScrollerEventType.DECEL_START));
-    }
-    _activeGesture = false;
-  }
-
-  void onDragMove() {
-    if (_isStopping || (!_activeGesture && _dragInProgress)) {
-      return;
-    }
-
-    assert(_contentStartOffset != null); // Content start not set
-    Coordinate contentStart = _contentStartOffset;
-    num newX = contentStart.x + _touchHandler.getDragDeltaX();
-    num newY = contentStart.y + _touchHandler.getDragDeltaY();
-    newY = _shouldScrollVertically() ?
-        _adjustValue(newY, _minPoint.y, _maxPoint.y) : 0;
-    newX = _shouldScrollHorizontally() ?
-        _adjustValue(newX, _minPoint.x, _maxPoint.x) : 0;
-    if (!_activeGesture) {
-      _activeGesture = true;
-      _dragInProgress = true;
-    }
-    if (!_started) {
-      _started = true;
-      onScrollerStart.dispatch(new Event(ScrollerEventType.SCROLLER_START));
-    }
-    _setContentOffset(newX, newY);
-  }
-
-  bool onDragStart(TouchEvent e) {
-    if (e.touches.length > 1) {
-      return false;
-    }
-    bool shouldHorizontal = _shouldScrollHorizontally();
-    bool shouldVertical = _shouldScrollVertically();
-    bool verticalish = _touchHandler.getDragDeltaY().abs() >
-        _touchHandler.getDragDeltaX().abs();
-    return !!(shouldVertical || shouldHorizontal && !verticalish);
-  }
-
-  void onTouchEnd() {
-  }
-
-  /**
-   * Prepare the scrollable area for possible movement.
-   */
-  bool onTouchStart(TouchEvent e) {
-    reconfigure(() {
-      final touch = e.touches[0];
-      if (_momentum.decelerating) {
-        e.preventDefault();
-        e.stopPropagation();
-        stop();
-      }
-      _contentStartOffset = _contentOffset.clone();
-      _snapContentOffsetToBounds();
-    });
-    return true;
-  }
-
-  /**
-   * Recalculate dimensions of the frame and the content. Adjust the minPoint
-   * and maxPoint allowed for scrolling and scroll to a valid position. Call
-   * this method if you know the frame or content has been updated. Called
-   * internally on every touchstart event the frame receives.
-   */
-  void reconfigure(Callback callback) {
-    _resize(() {
-      _snapContentOffsetToBounds();
-      callback();
-    });
-  }
-
-  void reset() {
-    stop();
-    _touchHandler.reset();
-    _maxOffset.x = 0;
-    _maxOffset.y = 0;
-    _minOffset.x = 0;
-    _minOffset.y = 0;
-    reconfigure(() => _setContentOffset(_maxPoint.x, _maxPoint.y));
-  }
-
-  /**
-   * Recalculate dimensions of the frame and the content. Adjust the minPoint
-   * and maxPoint allowed for scrolling.
-   */
-  void _resize(Callback callback) {
-    final frameRect = _frame.rect;
-    Future contentSizeFuture;
-
-    if (_lookupContentSizeDelegate !== null) {
-      contentSizeFuture = _lookupContentSizeDelegate();
-      contentSizeFuture.then((Size size) {
-        _contentSize = size;
-      });
-    } else {
-      contentSizeFuture = _element.rect;
-      contentSizeFuture.then((ElementRect rect) {
-        _contentSize = new Size(rect.scroll.width, rect.scroll.height);
-      });
-    }
-
-    joinFutures(<Future>[frameRect, contentSizeFuture], () {
-      _scrollSize = new Size(frameRect.value.offset.width,
-                             frameRect.value.offset.height);
-      Size adjusted = _getAdjustedContentSize();
-      _maxPoint = new Coordinate(-_maxOffset.x, -_maxOffset.y);
-      _minPoint = new Coordinate(
-          Math.min(
-              _scrollSize.width - adjusted.width + _minOffset.x, _maxPoint.x),
-          Math.min(
-              _scrollSize.height - adjusted.height + _minOffset.y, _maxPoint.y));
-      callback();
-    });
-  }
-
-  Coordinate _snapToBounds(num x, num y) {
-    num clampX = GoogleMath.clamp(_minPoint.x, x, _maxPoint.x);
-    num clampY = GoogleMath.clamp(_minPoint.y, y, _maxPoint.y);
-    return new Coordinate(clampX, clampY);
-  }
-
-  /**
-   * Translate the content to a new position specified in px.
-   */
-  void _setContentOffset(num x, num y) {
-    _contentOffset.x = x;
-    _contentOffset.y = y;
-    _setOffsetFunction(_element, x, y);
-    onContentMoved.dispatch(new Event(ScrollerEventType.CONTENT_MOVED));
-  }
-
-  /**
-   * Enable or disable momentum.
-   */
-  void setMomentum(bool enable) {
-    _momentumEnabled = enable;
-  }
-
-  /**
-   * Sets the vertical scrolled offset of the element where [y] is the amount
-   * of vertical space to be scrolled, in pixels.
-   */
-  void setVerticalOffset(num y) {
-    _setContentOffset(_contentOffset.x, y);
-  }
-
-   /**
-   * Whether the scrollable area should scroll horizontally. Only
-   * returns true if the client has enabled horizontal scrolling, and the
-   * content is wider than the frame.
-   */
-  bool _shouldScrollHorizontally() {
-    return horizontalEnabled && _scrollSize.width < _contentSize.width;
-  }
-
-  /**
-   * Whether the scrollable area should scroll vertically. Only
-   * returns true if the client has enabled vertical scrolling.
-   * Vertical bouncing will occur even if frame is taller than content, because
-   * this is what iPhone web apps tend to do. If this is not the desired
-   * behavior, either disable vertical scrolling for this scroller or add a
-   * 'bouncing' parameter to this interface.
-   */
-  bool _shouldScrollVertically() {
-    return verticalEnabled;
-  }
-
-  /**
-   * In the event that the content is currently beyond the bounds of
-   * the frame, snap it back in to place.
-   */
-  void _snapContentOffsetToBounds() {
-    num clampX =
-        GoogleMath.clamp(_minPoint.x, _contentOffset.x, _maxPoint.x);
-    num clampY =
-        GoogleMath.clamp(_minPoint.y, _contentOffset.y, _maxPoint.y);
-    if (_contentOffset.x != clampX || _contentOffset.y != clampY) {
-      _setContentOffset(clampX, clampY);
-    }
-  }
-
-  /**
-   * Initiate the deceleration behavior given a flick [velocity].
-   * Returns true if deceleration has been initiated.
-   */
-  bool _startDeceleration(Coordinate velocity,
-                          [num decelerationFactor = null]) {
-    if (!_shouldScrollHorizontally()) {
-      velocity.x = 0;
-    }
-    if (!_shouldScrollVertically()) {
-      velocity.y = 0;
-    }
-    assert(_minPoint != null); // Min point is not set
-    assert(_maxPoint != null); // Max point is not set
-    return _momentum.start(velocity, _minPoint, _maxPoint, _contentOffset,
-                           decelerationFactor);
-  }
-
-  Coordinate stop() {
-    return _momentum.stop();
-  }
-
-  /**
-   * Stop the deceleration of the scrollable content given a new position in px.
-   */
-  void _stopDecelerating(num x, num y) {
-    _momentum.stop();
-    _setContentOffset(x, y);
-  }
-
-  static Function _getOffsetFunction(int scrollTechnique) {
-    return scrollTechnique == ScrollerScrollTechnique.TRANSFORM_3D ?
-        (el, x, y) { FxUtil.setTranslate(el, x, y, 0); } :
-        (el, x, y) { FxUtil.setLeftAndTop(el, x, y); };
-  }
-}
-
-// TODO(jacobr): cleanup this class of enum constants.
-class ScrollerEventType {
-  static final SCROLLER_START = "scroller:scroll_start";
-  static final SCROLLER_END = "scroller:scroll_end";
-  static final DRAG_END = "scroller:drag_end";
-  static final CONTENT_MOVED = "scroller:content_moved";
-  static final DECEL_START = "scroller:decel_start";
-}
-
-// TODO(jacobr): for now this ignores capture.
-class SimpleEventListenerList implements EventListenerList {
-  // Ignores capture for now.
-  List<EventListener> _listeners;
-
-  SimpleEventListenerList() : _listeners = new List<EventListener>() { }
-
-  EventListenerList add(EventListener handler, [bool useCapture = false]) {
-    _add(handler, useCapture);
-    return this;
-  }
-
-  EventListenerList remove(EventListener handler, [bool useCapture = false]) {
-    _remove(handler, useCapture);
-    return this;
-  }
-
-  EventListenerList addCapture(EventListener handler) {
-    _add(handler, true);
-    return this;
-  }
-
-  EventListenerList removeCapture(EventListener handler) {
-    _remove(handler, true);
-    return this;
-  }
-
-  void _add(EventListener handler, bool useCapture) {
-    _listeners.add(handler);
-  }
-
-  void _remove(EventListener handler, bool useCapture) {
-    // TODO(jacobr): implemenet as needed.
-    throw 'Not implemented yet.';
-  }
-
-  bool dispatch(Event evt) {
-    for (EventListener listener in _listeners) {
-      listener(evt);
-    }
-  }
-}
-
-class ScrollerScrollTechnique {
-  static final TRANSFORM_3D = 1;
-  static final RELATIVE_POSITIONING = 2;
-}