Rolling forward https://codereview.chromium.org/1155683008/ which was

third_party/polymer/v0_8/components-chromium/paper-drawer-panel/paper-drawer-panel-extracted.js

-
-
-  (function() {
-
-    'use strict';
-
-   // this would be the only `paper-drawer-panel` in
-   // the whole app that can be in `dragging` state
-    var sharedPanel = null;
-
-    function classNames(obj) {
-      var classes = [];
-      for (var key in obj) {
-        if (obj.hasOwnProperty(key) && obj[key]) {
-          classes.push(key);
-        }
-      }
-
-      return classes.join(' ');
-    }
-
-    Polymer({
-
-      is: 'paper-drawer-panel',
-
-      /**
-       * Fired when the narrow layout changes.
-       *
-       * @event paper-responsive-change {{narrow: boolean}} detail -
-       *     narrow: true if the panel is in narrow layout.
-       */
-
-      /**
-       * Fired when the selected panel changes.
-       *
-       * Listening for this event is an alternative to observing changes in the `selected` attribute.
-       * This event is fired both when a panel is selected and deselected.
-       * The `isSelected` detail property contains the selection state.
-       *
-       * @event paper-select {{isSelected: boolean, item: Object}} detail -
-       *     isSelected: True for selection and false for deselection.
-       *     item: The panel that the event refers to.
-       */
-
-      properties: {
-
-        /**
-         * The panel to be selected when `paper-drawer-panel` changes to narrow
-         * layout.
-         */
-        defaultSelected: {
-          type: String,
-          value: 'main'
-        },
-
-        /**
-         * If true, swipe from the edge is disable.
-         */
-        disableEdgeSwipe: {
-          type: Boolean,
-          value: false
-        },
-
-        /**
-         * If true, swipe to open/close the drawer is disabled.
-         */
-        disableSwipe: {
-          type: Boolean,
-          value: false
-        },
-
-        /**
-         * Whether the user is dragging the drawer interactively.
-         */
-        dragging: {
-          type: Boolean,
-          value: false
-        },
-
-        /**
-         * Width of the drawer panel.
-         */
-        drawerWidth: {
-          type: String,
-          value: '256px'
-        },
-
-        /**
-         * How many pixels on the side of the screen are sensitive to edge
-         * swipes and peek.
-         */
-        edgeSwipeSensitivity: {
-          type: Number,
-          value: 30
-        },
-
-        /**
-         * If true, ignore `responsiveWidth` setting and force the narrow layout.
-         */
-        forceNarrow: {
-          type: Boolean,
-          value: false
-        },
-
-        /**
-         * Whether the browser has support for the transform CSS property.
-         */
-        hasTransform: {
-          type: Boolean,
-          value: function() {
-            return 'transform' in this.style;
-          }
-        },
-
-        /**
-         * Whether the browser has support for the will-change CSS property.
-         */
-        hasWillChange: {
-          type: Boolean,
-          value: function() {
-            return 'willChange' in this.style;
-          }
-        },
-
-        /**
-         * Returns true if the panel is in narrow layout.  This is useful if you
-         * need to show/hide elements based on the layout.
-         */
-        narrow: {
-          reflectToAttribute: true,
-          type: Boolean,
-          value: false,
-          notify: true
-        },
-
-        /**
-         * Whether the drawer is peeking out from the edge.
-         */
-        peeking: {
-          type: Boolean,
-          value: false
-        },
-
-        /**
-         * Max-width when the panel changes to narrow layout.
-         */
-        responsiveWidth: {
-          type: String,
-          value: '640px'
-        },
-
-        /**
-         * If true, position the drawer to the right.
-         */
-        rightDrawer: {
-          type: Boolean,
-          value: false
-        },
-
-        /**
-         * The panel that is being selected. `drawer` for the drawer panel and
-         * `main` for the main panel.
-         */
-        selected: {
-          reflectToAttribute: true,
-          type: String,
-          value: null
-        },
-
-        /**
-         * The attribute on elements that should toggle the drawer on tap, also elements will
-         * automatically be hidden in wide layout.
-         */
-        drawerToggleAttribute: {
-          type: String,
-          value: 'paper-drawer-toggle'
-        },
-
-        /**
-         * Whether the transition is enabled.
-         */
-        transition: {
-          type: Boolean,
-          value: false
-        },
-
-      },
-
-      listeners: {
-        tap: '_onTap',
-        track: '_onTrack',
-        down: '_downHandler',
-        up: '_upHandler'
-      },
-
-      observers: [
-        '_forceNarrowChanged(forceNarrow, defaultSelected)'
-      ],
-
-      /**
-       * Toggles the panel open and closed.
-       *
-       * @method togglePanel
-       */
-      togglePanel: function() {
-        if (this._isMainSelected()) {
-          this.openDrawer();
-        } else {
-          this.closeDrawer();
-        }
-      },
-
-      /**
-       * Opens the drawer.
-       *
-       * @method openDrawer
-       */
-      openDrawer: function() {
-        this.selected = 'drawer';
-      },
-
-      /**
-       * Closes the drawer.
-       *
-       * @method closeDrawer
-       */
-      closeDrawer: function() {
-        this.selected = 'main';
-      },
-
-      ready: function() {
-        // Avoid transition at the beginning e.g. page loads and enable
-        // transitions only after the element is rendered and ready.
-        this.transition = true;
-      },
-
-      _computeIronSelectorClass: function(narrow, transition, dragging, rightDrawer) {
-        return classNames({
-          dragging: dragging,
-          'narrow-layout': narrow,
-          'right-drawer': rightDrawer,
-          'left-drawer': !rightDrawer,
-          transition: transition
-        });
-      },
-
-      _computeDrawerStyle: function(drawerWidth) {
-        return 'width:' + drawerWidth + ';';
-      },
-
-      _computeMainStyle: function(narrow, rightDrawer, drawerWidth) {
-        var style = '';
-
-        style += 'left:' + ((narrow || rightDrawer) ? '0' : drawerWidth) + ';';
-
-        if (rightDrawer) {
-          style += 'right:' + (narrow ? '' : drawerWidth) + ';';
-        } else {
-          style += 'right:;';
-        }
-
-        return style;
-      },
-
-      _computeMediaQuery: function(forceNarrow, responsiveWidth) {
-        return forceNarrow ? '' : '(max-width: ' + responsiveWidth + ')';
-      },
-
-      _computeSwipeOverlayHidden: function(narrow, disableEdgeSwipe) {
-        return !narrow || disableEdgeSwipe;
-      },
-
-      _onTrack: function(e) {
-        if (sharedPanel && this !== sharedPanel) {
-          return;
-        }
-        switch (e.detail.state) {
-          case 'start':
-            this._trackStart(e);
-            break;
-          case 'track':
-            this._trackX(e);
-            break;
-          case 'end':
-            this._trackEnd(e);
-            break;
-        }
-
-      },
-
-      _responsiveChange: function(narrow) {
-        this.narrow = narrow;
-
-        if (this.narrow) {
-          this.selected = this.defaultSelected;
-        }
-
-        this.setScrollDirection(this._swipeAllowed() ? 'y' : 'all');
-        this.fire('paper-responsive-change', {narrow: this.narrow});
-      },
-
-      _onQueryMatchesChanged: function(e) {
-        this._responsiveChange(e.detail.value);
-      },
-
-      _forceNarrowChanged: function() {
-        // set the narrow mode only if we reached the `responsiveWidth`
-        this._responsiveChange(this.forceNarrow || this.$.mq.queryMatches);
-      },
-
-      _swipeAllowed: function() {
-        return this.narrow && !this.disableSwipe;
-      },
-
-      _isMainSelected: function() {
-        return this.selected === 'main';
-      },
-
-      _startEdgePeek: function() {
-        this.width = this.$.drawer.offsetWidth;
-        this._moveDrawer(this._translateXForDeltaX(this.rightDrawer ?
-            -this.edgeSwipeSensitivity : this.edgeSwipeSensitivity));
-        this.peeking = true;
-      },
-
-      _stopEdgePeek: function() {
-        if (this.peeking) {
-          this.peeking = false;
-          this._moveDrawer(null);
-        }
-      },
-
-      _downHandler: function(e) {
-        if (!this.dragging && this._isMainSelected() && this._isEdgeTouch(e) && !sharedPanel) {
-          this._startEdgePeek();
-          // grab this panel
-          sharedPanel = this;
-        }
-      },
-
-      _upHandler: function() {
-        this._stopEdgePeek();
-        // release the panel
-        sharedPanel = null;
-      },
-
-      _onTap: function(e) {
-        var targetElement = Polymer.dom(e).localTarget;
-        var isTargetToggleElement = targetElement &&
-          this.drawerToggleAttribute &&
-          targetElement.hasAttribute(this.drawerToggleAttribute);
-
-        if (isTargetToggleElement) {
-          this.togglePanel();
-        }
-      },
-
-      _isEdgeTouch: function(e) {
-        var x = e.detail.x;
-
-        return !this.disableEdgeSwipe && this._swipeAllowed() &&
-          (this.rightDrawer ?
-            x >= this.offsetWidth - this.edgeSwipeSensitivity :
-            x <= this.edgeSwipeSensitivity);
-      },
-
-      _trackStart: function() {
-        if (this._swipeAllowed()) {
-          sharedPanel = this;
-          this.dragging = true;
-
-          if (this._isMainSelected()) {
-            this.dragging = this.peeking || this._isEdgeTouch(event);
-          }
-
-          if (this.dragging) {
-            this.width = this.$.drawer.offsetWidth;
-            this.transition = false;
-          }
-        }
-      },
-
-      _translateXForDeltaX: function(deltaX) {
-        var isMain = this._isMainSelected();
-
-        if (this.rightDrawer) {
-          return Math.max(0, isMain ? this.width + deltaX : deltaX);
-        } else {
-          return Math.min(0, isMain ? deltaX - this.width : deltaX);
-        }
-      },
-
-      _trackX: function(e) {
-        if (this.dragging) {
-          var dx = e.detail.dx;
-
-          if (this.peeking) {
-            if (Math.abs(dx) <= this.edgeSwipeSensitivity) {
-              // Ignore trackx until we move past the edge peek.
-              return;
-            }
-            this.peeking = false;
-          }
-
-          this._moveDrawer(this._translateXForDeltaX(dx));
-        }
-      },
-
-      _trackEnd: function(e) {
-        if (this.dragging) {
-          var xDirection = e.detail.dx > 0;
-
-          this.dragging = false;
-          this.transition = true;
-          sharedPanel = null;
-          this._moveDrawer(null);
-
-          if (this.rightDrawer) {
-            this[xDirection ? 'closeDrawer' : 'openDrawer']();
-          } else {
-            this[xDirection ? 'openDrawer' : 'closeDrawer']();
-          }
-        }
-      },
-
-      _transformForTranslateX: function(translateX) {
-        if (translateX === null) {
-          return '';
-        }
-
-        return this.hasWillChange ? 'translateX(' + translateX + 'px)' :
-            'translate3d(' + translateX + 'px, 0, 0)';
-      },
-
-      _moveDrawer: function(translateX) {
-        var s = this.$.drawer.style;
-
-        if (this.hasTransform) {
-          s.transform = this._transformForTranslateX(translateX);
-        } else {
-          s.webkitTransform = this._transformForTranslateX(translateX);
-        }
-      }
-
-    });
-
-  }());
-