Add DisplayLayoutManagerMulti (WIP)

chrome/browser/resources/options/chromeos/display_layout_manager_multi.js

+/**
+ * @fileoverview Description of this file.
+ */
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+cr.exportPath('options');
+
+cr.define('options', function() {
+  'use strict';
+
+  var DisplayLayoutManager = options.DisplayLayoutManager;
+
+  var sIdPrefix = 'fakeId';
+
+  var gFakeDisplayNum = 3;
+  var gFakeDisplays = [];
+
+  /**
+   * @constructor
+   * @extends {options.DisplayLayoutManager}
+   */
+  function DisplayLayoutManagerMulti() {
+    DisplayLayoutManager.call(this);
+  }
+
+  // Helper class for display layout management. Implements logic for laying
+  // out 3+ displays.
+  DisplayLayoutManagerMulti.prototype = {
+    __proto__: DisplayLayoutManager.prototype,
+
+    /** @type {string} */
+    dragId_: '',
+
+    /** @type {string} */
+    dragParentId_: '',
+
+    /** @type {options.DisplayLayoutType} */
+    dragLayoutType_: options.DisplayLayoutType.RIGHT,
+
+    /** @override */
+    createDisplayArea: function(displayAreaDiv, minVisualScale) {
+      // Add fake displays just before creating divs.
+      this.createFakeDisplays_(gFakeDisplayNum);
+      for (var i = 0; i < gFakeDisplayNum; ++i) {
+        var fake = gFakeDisplays[i];
+        this.displayLayoutMap_[fake.id] = fake;
+      }
+      return DisplayLayoutManager.prototype.createDisplayArea.call(
+          this, displayAreaDiv, minVisualScale);
+    },
+
+    /** @override */
+    setFocusedId: function(focusedId) {
+      DisplayLayoutManager.prototype.setFocusedId.call(this, focusedId);
+      var layout = this.displayLayoutMap_[focusedId];
+      this.highlightParentEdge_(layout.parentId, layout.layoutType);
+    },
+
+    /** @override */
+    updatePosition: function(id, newPosition) {
+      this.dragId_ = id;
+      var layout = this.displayLayoutMap_[id];
+      this.dragParentId_ = this.findClosest_(layout, newPosition);
+      var parent = this.displayLayoutMap_[this.dragParentId_];
+      this.dragLayoutType_ =
+          this.getLayoutTypeForPosition_(layout.div, parent.div, newPosition);
+      this.updateDivPosition_(
+          layout.div, newPosition, parent.div, this.dragLayoutType_);
+      this.highlightParentEdge_(this.dragParentId_, this.dragLayoutType_);
+    },
+
+    /** @override */
+    finalizePosition: function(id) {
+      if (id != this.dragId_)
+        return false;
+
+      var layout = this.displayLayoutMap_[id];
+      var parent = this.displayLayoutMap_[this.dragParentId_];
+
+      // All immediate children of |layout| need to be re-parented.
+      var orphans = this.findChildren_(id, false /* do not recurse */);
+
+      // Special case: re-parenting to a descendant. Parent the immediate child
+      // to the dragged display's parent and treat that as the moved layout.
+      var newParent = parent;
+      while (newParent) {
+        if (newParent.parentId == '')
+          break;
+        if (newParent.parentId == id) {
+          newParent.parentId = layout.parentId;
+          break;
+        }
+        newParent = this.displayLayoutMap_[newParent.parentId];
+      }
+
+      // Re-parent the dragged display.
+      layout.parentId = this.dragParentId_;
+      layout.layoutType = this.dragLayoutType_;
+
+      // Snap to corners and calculate the offset from the new parent. This does
+      // not depend on any unresolved child layout.
+      this.adjustCorners_(layout.div, parent.div, this.dragLayoutType_);
+      this.calculateOffset_(layout);
+
+      // Update any orphaned children, which may include |id|.
+      this.updateOrphans_(orphans);
+
+      // Update the fake displays.
+      for (var i = 0; i < gFakeDisplayNum; ++i) {
+        var fakeId = gFakeDisplays[i].id;
+        var fake = Object.assign({}, this.displayLayoutMap_[fakeId]);
+        gFakeDisplays[i] = fake;
+        fake.bounds = this.calcLayoutBounds_(fake);
+      }
+
+      return layout.originalDivOffsets.x != layout.div.offsetLeft ||
+          layout.originalDivOffsets.y != layout.div.offsetTop;
+    },
+
+    /**
+     * @param {Array<string>=} orphanedIds The list of ids affected by the move.
+     * @private
+     */
+    updateOrphans_(orphanedIds) {
+      var orphans = orphanedIds.slice();
+      for (var orphan of orphanedIds) {
+        var newOrphans = this.findChildren_(orphan, true /* recurse */);
+        // If the dragged display was re-parented to one of its children,
+        // there may be duplicates so merge the lists.
+        for (var o of newOrphans) {
+          if (!orphans.includes(o))
+            orphans.push(o);
+        }
+      }
+
+      // Re-parent each orphan to a layout that is not a member of |orphans|.
+      // We remove each orphan from the list so that subsequent orphans can be
+      // parented to initial (primary) orphans.
+      while (orphans.length) {
+        var childId = orphans.shift();
+        var child = this.displayLayoutMap_[childId];
+
+        if (childId == this.dragId_) {
+          // Preserve the layout and offset of the dragged div.
+          this.calcLayoutBounds_(child);
+          this.layoutDivFromBounds_(child);
+          continue;
+        }
+
+        var pos = {x: child.div.offsetLeft, y: child.div.offsetTop};
+        var newParentId = this.findClosest_(child, pos, orphans);
+        child.parentId = newParentId;
+        // If all displays are orphans, newParentId will be empty.
+        if (newParentId != '') {
+          var parent = this.displayLayoutMap_[newParentId];
+          var layoutType =
+              this.getLayoutTypeForPosition_(child.div, parent.div, pos);
+          this.updateDivPosition_(child.div, pos, parent.div, layoutType);
+          this.adjustCorners_(child.div, parent.div, child.layoutType);
+          this.calculateOffset_(child);
+        }
+        // TODO(stevenjb): Set bounds and send child update.
+      }
+    },
+
+    /**
+     * @param {string} parentId
+     * @param {boolean} recurse Include descendants of children.
+     * @return {!Array<string>}
+     * @private
+     */
+    findChildren_(parentId, recurse) {
+      var children = [];
+      for (var childId in this.displayLayoutMap_) {
+        if (childId == parentId)
+          continue;
+        if (this.displayLayoutMap_[childId].parentId == parentId) {
+          // Insert immediate children at the front of the array.
+          children.unshift(childId);
+          if (recurse) {
+            // Descendants get added to the end of the list.
+            children = children.concat(this.findChildren_(childId, true));
+          }
+        }
+      }
+      return children;
+    },
+
+    /**
+     * Finds the display closest to |position| ignoring |child|.
+     * @param {options.DisplayLayout} child
+     * @param {options.DisplayPosition} position
+     * @param {Array<string>=} opt_ignore Ids to ignore.
+     * @return {string}
+     * @private
+     */
+    findClosest_: function(child, position, opt_ignore) {
+      var closestDist = undefined;
+      var x = position.x + child.div.offsetWidth / 2;
+      var y = position.y + child.div.offsetHeight / 2;
+      var closestId = '', closestDelta2;
+      for (var id in this.displayLayoutMap_) {
+        if (id == child.id)
+          continue;
+        if (opt_ignore && opt_ignore.includes(id))
+          continue;
+        var div = this.displayLayoutMap_[id].div;
+        var left = div.offsetLeft;
+        var top = div.offsetTop;
+        var width = div.offsetWidth;
+        var height = div.offsetHeight;
+        if (x >= left && x < left + width && y >= top && y < top + height)
+          return id;  // point is inside rect
+        var dx, dy;
+        if (x < left)
+          dx = left - x;
+        else if (x > left + width)
+          dx = x - (left + width);
+        else
+          dx = 0;
+        if (y < top)
+          dy = top - y;
+        else if (y > top + height)
+          dy = y - (top + height);
+        else
+          dy = 0;
+        var delta2 = dx * dx + dy * dy;
+        if (closestId == '' || delta2 < closestDelta2) {
+          closestId = id;
+          closestDelta2 = delta2;
+        }
+      }
+      return closestId;
+    },
+
+    /**
+     * Calculates the layoutType for |position| relative to |parentDiv|.
+     * @param {?HTMLElement} div
+     * @param {?HTMLElement} parentDiv
+     * @param {options.DisplayPosition} position
+     * @return {options.DisplayLayoutType}
+     * @private
+     */
+    getLayoutTypeForPosition_: function(div, parentDiv, position) {
+      // Translate position from top-left to center.
+      var x = position.x + div.offsetWidth / 2;
+      var y = position.y + div.offsetHeight / 2;
+
+      // Determine the distance from the new position to both of the near edges.
+      var div = parentDiv;
+      var left = div.offsetLeft;
+      var top = div.offsetTop;
+      var width = div.offsetWidth;
+      var height = div.offsetHeight;
+      // Signed deltas to center.
+      var dx = x - (left + width / 2);
+      var dy = y - (top + height / 2);
+      // Unsigned distance to each edge.
+      var distx = Math.abs(dx) - width / 2;
+      var disty = Math.abs(dy) - height / 2;
+      if (distx > disty) {
+        if (dx < 0)
+          return options.DisplayLayoutType.LEFT;
+        else
+          return options.DisplayLayoutType.RIGHT;
+      } else {
+        if (dy < 0)
+          return options.DisplayLayoutType.TOP;
+        else
+          return options.DisplayLayoutType.BOTTOM;
+      }
+    },
+
+    /**
+     * Update the location |div| to the position closest to |newPosition| along
+     * the edge of |parentDiv| specified by |layoutType|.
+     * @param {?HTMLElement} div
+     * @param {options.DisplayPosition} newPosition
+     * @param {?HTMLElement} parentDiv
+     * @param {!options.DisplayLayoutType} layoutType
+     * @private
+     */
+    updateDivPosition_(div, newPosition, parentDiv, layoutType) {
+      var snapX = (layoutType == options.DisplayLayoutType.LEFT ||
+                   layoutType == options.DisplayLayoutType.RIGHT) ?
+          0 /* infinite */ :
+          undefined /* default */;
+      var snapY = (layoutType == options.DisplayLayoutType.TOP ||
+                   layoutType == options.DisplayLayoutType.BOTTOM) ?
+          0 /* infinite */ :
+          undefined /* default */;
+      newPosition.x = this.snapToEdge_(
+          newPosition.x, div.offsetWidth, parentDiv.offsetLeft,
+          parentDiv.offsetWidth, snapX);
+      newPosition.y = this.snapToEdge_(
+          newPosition.y, div.offsetHeight, parentDiv.offsetTop,
+          parentDiv.offsetHeight, snapY);
+
+      this.setDivPosition_(div, newPosition, parentDiv, layoutType);
+    },
+
+    /**
+     * Highlights the edge of the div associated with |parentId| based on
+     * |layoutType|.
+     * @param {string} parentId
+     * @param {options.DisplayLayoutType} layoutType
+     * @private
+     */
+    highlightParentEdge_(parentId, layoutType) {
+      for (var tid in this.displayLayoutMap_) {
+        var tlayout = this.displayLayoutMap_[tid];
+        var highlight = '';
+        if (tlayout.id == parentId) {
+          switch (layoutType) {
+            case options.DisplayLayoutType.RIGHT:
+              highlight = 'displays-parent-right';
+              break;
+            case options.DisplayLayoutType.LEFT:
+              highlight = 'displays-parent-left';
+              break;
+            case options.DisplayLayoutType.TOP:
+              highlight = 'displays-parent-top';
+              break;
+            case options.DisplayLayoutType.BOTTOM:
+              highlight = 'displays-parent-bottom';
+              break;
+          }
+        }
+        tlayout.div.classList.toggle(
+            'displays-parent-right', highlight == 'displays-parent-right');
+        tlayout.div.classList.toggle(
+            'displays-parent-left', highlight == 'displays-parent-left');
+        tlayout.div.classList.toggle(
+            'displays-parent-top', highlight == 'displays-parent-top');
+        tlayout.div.classList.toggle(
+            'displays-parent-bottom', highlight == 'displays-parent-bottom');
+      }
+    },
+
+    createFakeDisplays_: function(num) {
+      if (num != gFakeDisplayNum)
+        gFakeDisplays = [];
+      var primary;
+      for (var id in this.displayLayoutMap_) {
+        var layout = this.displayLayoutMap_[id];
+        if (layout.parentId == '')
+          primary = layout;
+      }
+      for (var i = 0; i < num; ++i) {
+        if (i < gFakeDisplays.length) {
+          gFakeDisplays[i].div = null;
+        } else {
+          var fakeId = sIdPrefix + i;
+          var layoutType = /** @type {options.DisplayLayoutType} */ (i % 4);
+          var fakeDisplayLayout = this.createDisplayLayout(
+              fakeId, 'Fake Display ' + i, primary.bounds, layoutType,
+              primary.id);
+          fakeDisplayLayout.bounds = this.calcLayoutBounds_(fakeDisplayLayout);
+          gFakeDisplays.push(fakeDisplayLayout);
+        }
+      }
+    },
+
+    calcLayoutBounds_: function(layout) {
+      if (layout.parentId == '')
+        return layout.bounds;
+      var parent = this.displayLayoutMap_[layout.parentId];
+      // Parent layout bounds may not be calculated yet, so calculate (but
+      // do not set) them.
+      var parentBounds = this.calcLayoutBounds_(parent);
+      var left = 0, top = 0;
+      switch (layout.layoutType) {
+        case options.DisplayLayoutType.TOP:
+          left = parentBounds.left + layout.offset;
+          top = parentBounds.top - layout.bounds.height;
+          break;
+        case options.DisplayLayoutType.RIGHT:
+          left = parentBounds.left + parentBounds.width;
+          top = parentBounds.top + layout.offset;
+          break;
+        case options.DisplayLayoutType.BOTTOM:
+          left = parentBounds.left + layout.offset;
+          top = parentBounds.top + parentBounds.height;
+          break;
+        case options.DisplayLayoutType.LEFT:
+          left = parentBounds.left - layout.bounds.width;
+          top = parentBounds.top + layout.offset;
+          break;
+      }
+      return {
+        left: left,
+        top: top,
+        width: layout.bounds.width,
+        height: layout.bounds.height
+      };
+    }
+
+  };
+
+  // Export
+  return {DisplayLayoutManagerMulti: DisplayLayoutManagerMulti};
+});