forked from mirrors/gecko-dev
317 lines
11 KiB
JavaScript
317 lines
11 KiB
JavaScript
/* 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";
|
|
|
|
ChromeUtils.import("resource:///modules/CustomizableUI.jsm");
|
|
ChromeUtils.import("resource://gre/modules/XPCOMUtils.jsm");
|
|
|
|
var gManagers = new WeakMap();
|
|
|
|
const kPaletteId = "customization-palette";
|
|
|
|
var 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._horizontalDistance = null;
|
|
this.update(aContainer);
|
|
}
|
|
|
|
AreaPositionManager.prototype = {
|
|
_nodePositionStore: null,
|
|
|
|
update(aContainer) {
|
|
this._nodePositionStore = new WeakMap();
|
|
let last = null;
|
|
let singleItemHeight;
|
|
for (let child of aContainer.children) {
|
|
if (child.hidden) {
|
|
continue;
|
|
}
|
|
let coordinates = this._lazyStoreGet(child);
|
|
// We keep a baseline horizontal distance between nodes around
|
|
// for use when we can't compare with previous/next nodes
|
|
if (!this._horizontalDistance && last) {
|
|
this._horizontalDistance = coordinates.left - last.left;
|
|
}
|
|
// We also keep the basic height of items for use below:
|
|
if (!singleItemHeight) {
|
|
singleItemHeight = coordinates.height;
|
|
}
|
|
last = coordinates;
|
|
}
|
|
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(aContainer, aX, aY) {
|
|
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;
|
|
// 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 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(aContainer, aBefore, aSize, aIsFromThisArea) {
|
|
let isShifted = false;
|
|
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) {
|
|
isShifted = true;
|
|
}
|
|
if (isShifted) {
|
|
if (aIsFromThisArea && !this._lastPlaceholderInsertion) {
|
|
child.setAttribute("notransition", "true");
|
|
}
|
|
// Determine the CSS transform based on the next node:
|
|
child.style.transform = this._diffWithNext(child, 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");
|
|
}
|
|
}
|
|
this._lastPlaceholderInsertion = aBefore;
|
|
},
|
|
|
|
/**
|
|
* 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(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;
|
|
}
|
|
},
|
|
|
|
_diffWithNext(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];
|
|
// 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 nodes,
|
|
// if not, we'll use the width of the incoming node as a proxy:
|
|
xDiff = this._horizontalDistance || (this._dir == "ltr" ? 1 : -1) * 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(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(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(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(aNode, aDirection) {
|
|
let rv = aNode;
|
|
do {
|
|
rv = rv[aDirection + "Sibling"];
|
|
} while (rv && rv.getAttribute("hidden") == "true");
|
|
return rv;
|
|
}
|
|
};
|
|
|
|
var DragPositionManager = {
|
|
start(aWindow) {
|
|
let areas = [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));
|
|
}
|
|
}
|
|
},
|
|
|
|
stop() {
|
|
gManagers = new WeakMap();
|
|
},
|
|
|
|
getManagerForArea(aArea) {
|
|
return gManagers.get(aArea);
|
|
}
|
|
};
|
|
|
|
Object.freeze(DragPositionManager);
|