Add m-esr52 at 52.6.0

1 files changed, 420 insertions, 0 deletions

diff --git a/browser/components/customizableui/DragPositionManager.jsm b/browser/components/customizableui/DragPositionManager.jsm
new file mode 100644
index 000000000..1b4eb59dc
--- /dev/null
+++ b/browser/components/customizableui/DragPositionManager.jsm
@@ -0,0 +1,420 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+"use strict";
+
+Components.utils.import("resource:///modules/CustomizableUI.jsm");
+
+var gManagers = new WeakMap();
+
+const kPaletteId = "customization-palette";
+const kPlaceholderClass = "panel-customization-placeholder";
+
+this.EXPORTED_SYMBOLS = ["DragPositionManager"];
+
+function AreaPositionManager(aContainer) {
+  // Caching the direction and bounds of the container for quick access later:
+  let window = aContainer.ownerGlobal;
+  this._dir = window.getComputedStyle(aContainer).direction;
+  let containerRect = aContainer.getBoundingClientRect();
+  this._containerInfo = {
+    left: containerRect.left,
+    right: containerRect.right,
+    top: containerRect.top,
+    width: containerRect.width
+  };
+  this._inPanel = aContainer.id == CustomizableUI.AREA_PANEL;
+  this._horizontalDistance = null;
+  this.update(aContainer);
+}
+
+AreaPositionManager.prototype = {
+  _nodePositionStore: null,
+  _wideCache: null,
+
+  update: function(aContainer) {
+    this._nodePositionStore = new WeakMap();
+    this._wideCache = new Set();
+    let last = null;
+    let singleItemHeight;
+    for (let child of aContainer.children) {
+      if (child.hidden) {
+        continue;
+      }
+      let isNodeWide = this._checkIfWide(child);
+      if (isNodeWide) {
+        this._wideCache.add(child.id);
+      }
+      let coordinates = this._lazyStoreGet(child);
+      // We keep a baseline horizontal distance between non-wide nodes around
+      // for use when we can't compare with previous/next nodes
+      if (!this._horizontalDistance && last && !isNodeWide) {
+        this._horizontalDistance = coordinates.left - last.left;
+      }
+      // We also keep the basic height of non-wide items for use below:
+      if (!isNodeWide && !singleItemHeight) {
+        singleItemHeight = coordinates.height;
+      }
+      last = !isNodeWide ? coordinates : null;
+    }
+    if (this._inPanel) {
+      this._heightToWidthFactor = CustomizableUI.PANEL_COLUMN_COUNT;
+    } else {
+      this._heightToWidthFactor = this._containerInfo.width / singleItemHeight;
+    }
+  },
+
+  /**
+   * Find the closest node in the container given the coordinates.
+   * "Closest" is defined in a somewhat strange manner: we prefer nodes
+   * which are in the same row over nodes that are in a different row.
+   * In order to implement this, we use a weighted cartesian distance
+   * where dy is more heavily weighted by a factor corresponding to the
+   * ratio between the container's width and the height of its elements.
+   */
+  find: function(aContainer, aX, aY, aDraggedItemId) {
+    let closest = null;
+    let minCartesian = Number.MAX_VALUE;
+    let containerX = this._containerInfo.left;
+    let containerY = this._containerInfo.top;
+    for (let node of aContainer.children) {
+      let coordinates = this._lazyStoreGet(node);
+      let offsetX = coordinates.x - containerX;
+      let offsetY = coordinates.y - containerY;
+      let hDiff = offsetX - aX;
+      let vDiff = offsetY - aY;
+      // For wide widgets, we're always going to be further from the center
+      // horizontally. Compensate:
+      if (this.isWide(node)) {
+        hDiff /= CustomizableUI.PANEL_COLUMN_COUNT;
+      }
+      // Then compensate for the height/width ratio so that we prefer items
+      // which are in the same row:
+      hDiff /= this._heightToWidthFactor;
+
+      let cartesianDiff = hDiff * hDiff + vDiff * vDiff;
+      if (cartesianDiff < minCartesian) {
+        minCartesian = cartesianDiff;
+        closest = node;
+      }
+    }
+
+    // Now correct this node based on what we're dragging
+    if (closest) {
+      let doc = aContainer.ownerDocument;
+      let draggedItem = doc.getElementById(aDraggedItemId);
+      // If dragging a wide item, always pick the first item in a row:
+      if (this._inPanel && draggedItem &&
+          draggedItem.classList.contains(CustomizableUI.WIDE_PANEL_CLASS)) {
+        return this._firstInRow(closest);
+      }
+      let targetBounds = this._lazyStoreGet(closest);
+      let farSide = this._dir == "ltr" ? "right" : "left";
+      let outsideX = targetBounds[farSide];
+      // Check if we're closer to the next target than to this one:
+      // Only move if we're not targeting a node in a different row:
+      if (aY > targetBounds.top && aY < targetBounds.bottom) {
+        if ((this._dir == "ltr" && aX > outsideX) ||
+            (this._dir == "rtl" && aX < outsideX)) {
+          return closest.nextSibling || aContainer;
+        }
+      }
+    }
+    return closest;
+  },
+
+  /**
+   * "Insert" a "placeholder" by shifting the subsequent children out of the
+   * way. We go through all the children, and shift them based on the position
+   * they would have if we had inserted something before aBefore. We use CSS
+   * transforms for this, which are CSS transitioned.
+   */
+  insertPlaceholder: function(aContainer, aBefore, aWide, aSize, aIsFromThisArea) {
+    let isShifted = false;
+    let shiftDown = aWide;
+    for (let child of aContainer.children) {
+      // Don't need to shift hidden nodes:
+      if (child.getAttribute("hidden") == "true") {
+        continue;
+      }
+      // If this is the node before which we're inserting, start shifting
+      // everything that comes after. One exception is inserting at the end
+      // of the menupanel, in which case we do not shift the placeholders:
+      if (child == aBefore && !child.classList.contains(kPlaceholderClass)) {
+        isShifted = true;
+        // If the node before which we're inserting is wide, we should
+        // shift everything one row down:
+        if (!shiftDown && this.isWide(child)) {
+          shiftDown = true;
+        }
+      }
+      // If we're moving items before a wide node that were already there,
+      // it's possible it's not necessary to shift nodes
+      // including & after the wide node.
+      if (this.__undoShift) {
+        isShifted = false;
+      }
+      if (isShifted) {
+        // Conversely, if we're adding something before a wide node, for
+        // simplicity's sake we move everything including the wide node down:
+        if (this.__moveDown) {
+          shiftDown = true;
+        }
+        if (aIsFromThisArea && !this._lastPlaceholderInsertion) {
+          child.setAttribute("notransition", "true");
+        }
+        // Determine the CSS transform based on the next node:
+        child.style.transform = this._getNextPos(child, shiftDown, aSize);
+      } else {
+        // If we're not shifting this node, reset the transform
+        child.style.transform = "";
+      }
+    }
+    if (aContainer.lastChild && aIsFromThisArea &&
+        !this._lastPlaceholderInsertion) {
+      // Flush layout:
+      aContainer.lastChild.getBoundingClientRect();
+      // then remove all the [notransition]
+      for (let child of aContainer.children) {
+        child.removeAttribute("notransition");
+      }
+    }
+    delete this.__moveDown;
+    delete this.__undoShift;
+    this._lastPlaceholderInsertion = aBefore;
+  },
+
+  isWide: function(aNode) {
+    return this._wideCache.has(aNode.id);
+  },
+
+  _checkIfWide: function(aNode) {
+    return this._inPanel && aNode && aNode.firstChild &&
+           aNode.firstChild.classList.contains(CustomizableUI.WIDE_PANEL_CLASS);
+  },
+
+  /**
+   * Reset all the transforms in this container, optionally without
+   * transitioning them.
+   * @param aContainer    the container in which to reset transforms
+   * @param aNoTransition if truthy, adds a notransition attribute to the node
+   *                      while resetting the transform.
+   */
+  clearPlaceholders: function(aContainer, aNoTransition) {
+    for (let child of aContainer.children) {
+      if (aNoTransition) {
+        child.setAttribute("notransition", true);
+      }
+      child.style.transform = "";
+      if (aNoTransition) {
+        // Need to force a reflow otherwise this won't work.
+        child.getBoundingClientRect();
+        child.removeAttribute("notransition");
+      }
+    }
+    // We snapped back, so we can assume there's no more
+    // "last" placeholder insertion point to keep track of.
+    if (aNoTransition) {
+      this._lastPlaceholderInsertion = null;
+    }
+  },
+
+  _getNextPos: function(aNode, aShiftDown, aSize) {
+    // Shifting down is easy:
+    if (this._inPanel && aShiftDown) {
+      return "translate(0, " + aSize.height + "px)";
+    }
+    return this._diffWithNext(aNode, aSize);
+  },
+
+  _diffWithNext: function(aNode, aSize) {
+    let xDiff;
+    let yDiff = null;
+    let nodeBounds = this._lazyStoreGet(aNode);
+    let side = this._dir == "ltr" ? "left" : "right";
+    let next = this._getVisibleSiblingForDirection(aNode, "next");
+    // First we determine the transform along the x axis.
+    // Usually, there will be a next node to base this on:
+    if (next) {
+      let otherBounds = this._lazyStoreGet(next);
+      xDiff = otherBounds[side] - nodeBounds[side];
+      // If the next node is a wide item in the panel, check if we could maybe
+      // just move further out in the same row, without snapping to the next
+      // one. This happens, for example, if moving an item that's before a wide
+      // node within its own row of items. There will be space to drop this
+      // item within the row, and the rest of the items do not need to shift.
+      if (this.isWide(next)) {
+        let otherXDiff = this._moveNextBasedOnPrevious(aNode, nodeBounds,
+                                                       this._firstInRow(aNode));
+        // If this has the same sign as our original shift, we're still
+        // snapping to the start of the row. In this case, we should move
+        // everything after us a row down, so as not to display two nodes on
+        // top of each other:
+        // (we would be able to get away with checking for equality instead of
+        //  equal signs here, but one of these is based on the x coordinate of
+        //  the first item in row N and one on that for row N - 1, so this is
+        //  safer, as their margins might differ)
+        if ((otherXDiff < 0) == (xDiff < 0)) {
+          this.__moveDown = true;
+        } else {
+          // Otherwise, we succeeded and can move further out. This also means
+          // we can stop shifting the rest of the content:
+          xDiff = otherXDiff;
+          this.__undoShift = true;
+        }
+      } else {
+        // We set this explicitly because otherwise some strange difference
+        // between the height and the actual difference between line creeps in
+        // and messes with alignments
+        yDiff = otherBounds.top - nodeBounds.top;
+      }
+    } else {
+      // We don't have a sibling whose position we can use. First, let's see
+      // if we're also the first item (which complicates things):
+      let firstNode = this._firstInRow(aNode);
+      if (aNode == firstNode) {
+        // Maybe we stored the horizontal distance between non-wide nodes,
+        // if not, we'll use the width of the incoming node as a proxy:
+        xDiff = this._horizontalDistance || aSize.width;
+      } else {
+        // If not, we should be able to get the distance to the previous node
+        // and use the inverse, unless there's no room for another node (ie we
+        // are the last node and there's no room for another one)
+        xDiff = this._moveNextBasedOnPrevious(aNode, nodeBounds, firstNode);
+      }
+    }
+
+    // If we've not determined the vertical difference yet, check it here
+    if (yDiff === null) {
+      // If the next node is behind rather than in front, we must have moved
+      // vertically:
+      if ((xDiff > 0 && this._dir == "rtl") || (xDiff < 0 && this._dir == "ltr")) {
+        yDiff = aSize.height;
+      } else {
+        // Otherwise, we haven't
+        yDiff = 0;
+      }
+    }
+    return "translate(" + xDiff + "px, " + yDiff + "px)";
+  },
+
+  /**
+   * Helper function to find the transform a node if there isn't a next node
+   * to base that on.
+   * @param aNode           the node to transform
+   * @param aNodeBounds     the bounding rect info of this node
+   * @param aFirstNodeInRow the first node in aNode's row
+   */
+  _moveNextBasedOnPrevious: function(aNode, aNodeBounds, aFirstNodeInRow) {
+    let next = this._getVisibleSiblingForDirection(aNode, "previous");
+    let otherBounds = this._lazyStoreGet(next);
+    let side = this._dir == "ltr" ? "left" : "right";
+    let xDiff = aNodeBounds[side] - otherBounds[side];
+    // If, however, this means we move outside the container's box
+    // (i.e. the row in which this item is placed is full)
+    // we should move it to align with the first item in the next row instead
+    let bound = this._containerInfo[this._dir == "ltr" ? "right" : "left"];
+    if ((this._dir == "ltr" && xDiff + aNodeBounds.right > bound) ||
+        (this._dir == "rtl" && xDiff + aNodeBounds.left < bound)) {
+      xDiff = this._lazyStoreGet(aFirstNodeInRow)[side] - aNodeBounds[side];
+    }
+    return xDiff;
+  },
+
+  /**
+   * Get position details from our cache. If the node is not yet cached, get its position
+   * information and cache it now.
+   * @param aNode  the node whose position info we want
+   * @return the position info
+   */
+  _lazyStoreGet: function(aNode) {
+    let rect = this._nodePositionStore.get(aNode);
+    if (!rect) {
+      // getBoundingClientRect() returns a DOMRect that is live, meaning that
+      // as the element moves around, the rects values change. We don't want
+      // that - we want a snapshot of what the rect values are right at this
+      // moment, and nothing else. So we have to clone the values.
+      let clientRect = aNode.getBoundingClientRect();
+      rect = {
+        left: clientRect.left,
+        right: clientRect.right,
+        width: clientRect.width,
+        height: clientRect.height,
+        top: clientRect.top,
+        bottom: clientRect.bottom,
+      };
+      rect.x = rect.left + rect.width / 2;
+      rect.y = rect.top + rect.height / 2;
+      Object.freeze(rect);
+      this._nodePositionStore.set(aNode, rect);
+    }
+    return rect;
+  },
+
+  _firstInRow: function(aNode) {
+    // XXXmconley: I'm not entirely sure why we need to take the floor of these
+    // values - it looks like, periodically, we're getting fractional pixels back
+    // from lazyStoreGet. I've filed bug 994247 to investigate.
+    let bound = Math.floor(this._lazyStoreGet(aNode).top);
+    let rv = aNode;
+    let prev;
+    while (rv && (prev = this._getVisibleSiblingForDirection(rv, "previous"))) {
+      if (Math.floor(this._lazyStoreGet(prev).bottom) <= bound) {
+        return rv;
+      }
+      rv = prev;
+    }
+    return rv;
+  },
+
+  _getVisibleSiblingForDirection: function(aNode, aDirection) {
+    let rv = aNode;
+    do {
+      rv = rv[aDirection + "Sibling"];
+    } while (rv && rv.getAttribute("hidden") == "true")
+    return rv;
+  }
+}
+
+var DragPositionManager = {
+  start: function(aWindow) {
+    let areas = CustomizableUI.areas.filter((area) => CustomizableUI.getAreaType(area) != "toolbar");
+    areas = areas.map((area) => CustomizableUI.getCustomizeTargetForArea(area, aWindow));
+    areas.push(aWindow.document.getElementById(kPaletteId));
+    for (let areaNode of areas) {
+      let positionManager = gManagers.get(areaNode);
+      if (positionManager) {
+        positionManager.update(areaNode);
+      } else {
+        gManagers.set(areaNode, new AreaPositionManager(areaNode));
+      }
+    }
+  },
+
+  add: function(aWindow, aArea, aContainer) {
+    if (CustomizableUI.getAreaType(aArea) != "toolbar") {
+      return;
+    }
+
+    gManagers.set(aContainer, new AreaPositionManager(aContainer));
+  },
+
+  remove: function(aWindow, aArea, aContainer) {
+    if (CustomizableUI.getAreaType(aArea) != "toolbar") {
+      return;
+    }
+
+    gManagers.delete(aContainer);
+  },
+
+  stop: function() {
+    gManagers = new WeakMap();
+  },
+
+  getManagerForArea: function(aArea) {
+    return gManagers.get(aArea);
+  }
+};
+
+Object.freeze(DragPositionManager);