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

client/touch/Scrollbar.dart

Index: client/touch/Scrollbar.dart
===================================================================
--- client/touch/Scrollbar.dart	(revision 4144)
+++ client/touch/Scrollbar.dart	(working copy)
@@ -1,352 +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 scrollbar for the custom scrolling behavior
- * defined in [:Scroller:].
- */
-class Scrollbar implements ScrollListener {
-  /**
-   * The minimum size of scrollbars when not compressed.
-   */
-  static final _MIN_SIZE = 30;
-
-  /**
-   * The minimum compressed size of scrollbars. Scrollbars are compressed when
-   * the content is stretching past its boundaries.
-   */
-  static final _MIN_COMPRESSED_SIZE = 8;
-  /** Padding in pixels to add above and bellow the scrollbar. */
-  static final _PADDING_LENGTH = 10;
-  /**
-   * The amount of time to wait before hiding scrollbars after showing them.
-   * Measured in ms.
-   */
-  static final _DISPLAY_TIME = 300;
-  static final DRAG_CLASS_NAME = 'drag';
-
-  Scroller _scroller;
-  Element _frame;
-  bool _scrollInProgress = false;
-  bool _scrollBarDragInProgressValue = false;
-
-  /**
-   * Cached values of height and width. Keys will be 'height' and 'width'
-   * depending on if they are applied to vertical or horizontal scrollbar.
-   */
-  Map<String, num> _cachedSize;
-
-  /**
-   * This bound function will be used as the input to window.setTimeout when
-   * scheduling the hiding of the scrollbars.
-   */
-  Function _boundHideFn;
-
-  Element _verticalElement;
-  Element _horizontalElement;
-
-  int _currentScrollStartMouse;
-  num _currentScrollStartOffset;
-  bool _currentScrollVertical;
-  num _currentScrollRatio;
-  num _timerId;
-
-  bool _displayOnHover;
-  bool _hovering = false;
-
-  Scrollbar(Scroller scroller, [displayOnHover = true]) :
-      _displayOnHover = displayOnHover,
-      _scroller = scroller,
-      _frame = scroller.getFrame(),
-      _cachedSize = new Map<String, num>() {
-    _boundHideFn = () { _showScrollbars(false); };
-  }
-
-  bool get _scrollBarDragInProgress() => _scrollBarDragInProgressValue;
-
-  void set _scrollBarDragInProgress(bool value) {
-    _scrollBarDragInProgressValue = value;
-    _toggleClass(_verticalElement, DRAG_CLASS_NAME,
-        value && _currentScrollVertical);
-    _toggleClass(_horizontalElement, DRAG_CLASS_NAME,
-        value && !_currentScrollVertical);
-  }
-
-  // TODO(jacobr): move this helper method into the DOM.
-  void _toggleClass(Element e, String className, bool enabled) {
-    if (enabled) {
-      if (!e.classes.contains(className)) {
-        e.classes.add(className);
-      }
-    } else {
-      e.classes.remove(className);
-    }
-  }
-
-  /**
-   * Initializes elements and event handlers. Must be called after
-   * construction and before usage.
-   */
-  void initialize() {
-    // Don't initialize if we have already been initialized.
-    // TODO(jacobr): remove this once bugs are fixed and enterDocument is only
-    // called once by each view.
-    if (_verticalElement != null) {
-      return;
-    }
-    _verticalElement = new Element.html(
-        '<div class="touch-scrollbar touch-scrollbar-vertical"></div>');
-    _horizontalElement = new Element.html(
-        '<div class="touch-scrollbar touch-scrollbar-horizontal"></div>');
-    _scroller.addScrollListener(this);
-
-    Element scrollerEl = _scroller.getElement();
-
-    if (!Device.supportsTouch) {
-      _addEventListeners(
-          _verticalElement, _onStart, _onMove, _onEnd, _onEnd, true);
-      _addEventListeners(
-          _horizontalElement, _onStart, _onMove, _onEnd, _onEnd, true);
-    }
-
-    _scroller.addScrollListener(this);
-    _showScrollbars(false);
-    _scroller.onScrollerStart.add(_onScrollerStart);
-    _scroller.onScrollerEnd.add(_onScrollerEnd);
-    if (_displayOnHover) {
-      // TODO(jacobr): rather than adding all these event listeners we could
-      // instead attach a single global event listener and let data in the
-      // DOM drive.
-      _frame.on.click.add((Event e) {
-          // Always focus on click as one of our children isn't all focused.
-          if (!_frame.contains(document.activeElement)) {
-            scrollerEl.focus();
-          }
-        }, false);
-      _frame.on.mouseOver.add((Event e) {
-          final activeElement = document.activeElement;
-          // TODO(jacobr): don't steal focus from a child element or a truly
-          // focusable element. Only support stealing focus ffrom another
-          // element that was given fake focus.
-          if (activeElement is BodyElement ||
-              (!_frame.contains(activeElement) &&
-               activeElement is DivElement)) {
-            scrollerEl.focus();
-          }
-          if (_hovering == false) {
-            _hovering = true;
-            _cancelTimeout();
-            _showScrollbars(true);
-            refresh();
-          }
-        }, false);
-      _frame.on.mouseOut.add((e) {
-          _hovering = false;
-          // Start hiding immediately if we aren't
-          // scrolling or already in the process of
-          // hidng the scrollbar
-          if (!_scrollInProgress && _timerId == null) {
-            _boundHideFn();
-          }
-        }, false);
-    }
-  }
-
-  void _onStart(UIEvent e) {
-    Element elementOver = e.target;
-    if (elementOver == _verticalElement ||
-        elementOver == _horizontalElement) {
-      _currentScrollVertical = elementOver == _verticalElement;
-      if (_currentScrollVertical) {
-        _currentScrollStartMouse = e.pageY;
-        _currentScrollStartOffset = _scroller.getVerticalOffset();
-      } else {
-        _currentScrollStartMouse = e.pageX;
-        _currentScrollStartOffset = _scroller.getHorizontalOffset();
-      }
-      _refreshScrollRatio();
-      _scrollBarDragInProgress = true;
-      _scroller._momentum.abort();
-      e.stopPropagation();
-    }
-  }
-
-  void _refreshScrollRatio() {
-    Size contentSize = _scroller._getAdjustedContentSize();
-    if (_currentScrollVertical) {
-      _refreshScrollRatioHelper(
-          _scroller._scrollSize.height, contentSize.height);
-    } else {
-      _refreshScrollRatioHelper(_scroller._scrollSize.width,
-                          contentSize.width);
-    }
-  }
-
-
-  void _refreshScrollRatioHelper(num frameSize, num contentSize) {
-    num frameTravelDistance = frameSize - _defaultScrollSize(
-        frameSize, contentSize) -_PADDING_LENGTH * 2;
-    if (frameTravelDistance < 0.001) {
-      _currentScrollRatio = 0;
-    } else {
-      _currentScrollRatio = (contentSize - frameSize) / frameTravelDistance;
-    }
-  }
-
-  void _onMove(UIEvent e) {
-    if (!_scrollBarDragInProgress) {
-      return;
-    }
-    _refreshScrollRatio();
-    int coordinate = _currentScrollVertical ? e.pageY : e.pageX;
-    num delta = (coordinate - _currentScrollStartMouse) * _currentScrollRatio;
-    if (delta != 0) {
-      num x;
-      num y;
-      _currentScrollStartOffset -= delta;
-      if (_currentScrollVertical) {
-        x = _scroller.getHorizontalOffset();
-        y = _currentScrollStartOffset.toInt();
-      } else {
-        x = _currentScrollStartOffset.toInt();
-        y = _scroller.getVerticalOffset();
-      }
-      _scroller.setPosition(x, y);
-    }
-    _currentScrollStartMouse = coordinate;
-  }
-
-  void _onEnd(UIEvent e) {
-    _scrollBarDragInProgress = false;
-    // TODO(jacobr): make scrollbar less tightly coupled to the scroller.
-    _scroller.onScrollerDragEnd.dispatch(
-        new Event(ScrollerEventType.DRAG_END));
-  }
-
-
-  /**
-   * When scrolling ends, schedule a timeout to hide the scrollbars.
-   */
-  void _onScrollerEnd(Event e) {
-    _cancelTimeout();
-    _timerId = window.setTimeout(_boundHideFn, _DISPLAY_TIME);
-    _scrollInProgress = false;
-  }
-  void onScrollerMoved(num scrollX, num scrollY, bool decelerating) {
-    if (_scrollInProgress == false) {
-      // Display the scrollbar and then immediately prepare to hide it...
-      _onScrollerStart(null);
-      _onScrollerEnd(null);
-    }
-    updateScrollbars(scrollX, scrollY);
-  }
-
-  void refresh() {
-    if (_scrollInProgress == false && _hovering == false) {
-      // No need to refresh if not visible.
-      return;
-    }
-    _scroller._resize(() {
-      updateScrollbars(_scroller.getHorizontalOffset(),
-                       _scroller.getVerticalOffset());
-    });
-  }
-
-  void updateScrollbars(num scrollX, num scrollY) {
-    Size contentSize = _scroller._getAdjustedContentSize();
-    if (_scroller._shouldScrollHorizontally()) {
-      num scrollPercentX = _scroller.getHorizontalScrollPercent(scrollX);
-      _updateScrollbar(_horizontalElement, scrollX, scrollPercentX,
-                       _scroller._scrollSize.width,
-                       contentSize.width, 'right', 'width');
-    }
-    if (_scroller._shouldScrollVertically()) {
-      num scrollPercentY = _scroller.getVerticalScrollPercent(scrollY);
-      _updateScrollbar(_verticalElement, scrollY, scrollPercentY,
-                       _scroller._scrollSize.height,
-                       contentSize.height, 'bottom', 'height');
-    }
-  }
-
-  /**
-   * When scrolling starts, show scrollbars and clear hide intervals.
-   */
-  void _onScrollerStart(Event e) {
-    _scrollInProgress = true;
-    _cancelTimeout();
-    _showScrollbars(true);
-  }
-
-  void _cancelTimeout() {
-    if (_timerId != null) {
-      window.clearTimeout(_timerId);
-      _timerId = null;
-    }
-  }
-
-  /**
-   * Show or hide the scrollbars by changing the opacity.
-   */
-  void _showScrollbars(bool show) {
-    if (_hovering == true && _displayOnHover) {
-      show = true;
-    }
-    _toggleOpacity(_verticalElement, show);
-    _toggleOpacity(_horizontalElement, show);
-  }
-
-  _toggleOpacity(Element element, bool show) {
-    if (show) {
-      element.style.removeProperty("opacity");
-    } else {
-      element.style.opacity = '0';
-    }
-  }
-
-  num _defaultScrollSize(num frameSize, num contentSize) {
-    return GoogleMath.clamp(
-        (frameSize -_PADDING_LENGTH * 2) * frameSize / contentSize,
-        _MIN_SIZE, frameSize -_PADDING_LENGTH * 2);
-  }
-
-  /**
-   * Update the vertical or horizontal scrollbar based on the new scroll
-   * properties. The CSS property to adjust for position (bottom|right) is
-   * specified by [cssPos]. The CSS property to adjust for size (height|width)
-   * is specified by [cssSize].
-   */
-  void _updateScrollbar(Element element, num offset,
-                        num scrollPercent, num frameSize,
-                        num contentSize, String cssPos, String cssSize) {
-    if (!_cachedSize.containsKey(cssSize)) {
-      if (offset == null || contentSize < frameSize) {
-        return;
-      }
-      _frame.nodes.add(element);
-    }
-    num stretchPercent;
-    if (scrollPercent > 1) {
-      stretchPercent = scrollPercent - 1;
-    } else {
-      stretchPercent = scrollPercent < 0 ? -scrollPercent : 0;
-    }
-    num scrollPx = stretchPercent * (contentSize - frameSize);
-    num maxSize = _defaultScrollSize(frameSize, contentSize);
-    num size = Math.max(_MIN_COMPRESSED_SIZE, maxSize - scrollPx);
-    num maxOffset = frameSize - size -_PADDING_LENGTH  * 2;
-    num pos = GoogleMath.clamp(scrollPercent * maxOffset,
-                              0, maxOffset) + _PADDING_LENGTH;
-    pos = pos.round();
-    size = size.round();
-    final style = element.style;
-    style.setProperty(cssPos, '${pos}px', '');
-    if (_cachedSize[cssSize] != size) {
-      _cachedSize[cssSize] = size;
-      style.setProperty(cssSize, '${size}px', '');
-    }
-    if (element.parent == null) {
-      _frame.nodes.add(element);
-    }
-  }
-}