openmct/platform/features/layout/src/LayoutDrag.js
Victor Woeltjen ac5ac8d34e [Build] Remove boilerplate from scripts
No longer necessary after JSHint configuration.
2016-03-04 10:46:38 -08:00

116 lines
4.7 KiB
JavaScript

/*****************************************************************************
* Open MCT Web, Copyright (c) 2014-2015, United States Government
* as represented by the Administrator of the National Aeronautics and Space
* Administration. All rights reserved.
*
* Open MCT Web is licensed under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0.
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
* License for the specific language governing permissions and limitations
* under the License.
*
* Open MCT Web includes source code licensed under additional open source
* licenses. See the Open Source Licenses file (LICENSES.md) included with
* this source code distribution or the Licensing information page available
* at runtime from the About dialog for additional information.
*****************************************************************************/
define(
[],
function () {
/**
* Handles drag interactions on frames in layouts. This will
* provides new positions/dimensions for frames based on
* relative pixel positions provided; these will take into account
* the grid size (in a snap-to sense) and will enforce some minimums
* on both position and dimensions.
*
* The provided position and dimensions factors will determine
* whether this is a move or a resize, and what type of resize it
* will be. For instance, a position factor of [1, 1]
* will move a frame along with the mouse as the drag
* proceeds, while a dimension factor of [0, 0] will leave
* dimensions unchanged. Combining these in different
* ways results in different handles; a position factor of
* [1, 0] and a dimensions factor of [-1, 0] will implement
* a left-edge resize, as the horizontal position will move
* with the mouse while the horizontal dimensions shrink in
* kind (and vertical properties remain unmodified.)
*
* @param {object} rawPosition the initial position/dimensions
* of the frame being interacted with
* @param {number[]} posFactor the position factor
* @param {number[]} dimFactor the dimensions factor
* @param {number[]} the size of each grid element, in pixels
* @constructor
* @memberof platform/features/layout
*/
function LayoutDrag(rawPosition, posFactor, dimFactor, gridSize) {
this.rawPosition = rawPosition;
this.posFactor = posFactor;
this.dimFactor = dimFactor;
this.gridSize = gridSize;
}
// Convert a delta from pixel coordinates to grid coordinates,
// rounding to whole-number grid coordinates.
function toGridDelta(gridSize, pixelDelta) {
return pixelDelta.map(function (v, i) {
return Math.round(v / gridSize[i]);
});
}
// Utility function to perform element-by-element multiplication
function multiply(array, factors) {
return array.map(function (v, i) {
return v * factors[i];
});
}
// Utility function to perform element-by-element addition
function add(array, other) {
return array.map(function (v, i) {
return v + other[i];
});
}
// Utility function to perform element-by-element max-choosing
function max(array, other) {
return array.map(function (v, i) {
return Math.max(v, other[i]);
});
}
/**
* Get a new position object in grid coordinates, with
* position and dimensions both offset appropriately
* according to the factors supplied in the constructor.
* @param {number[]} pixelDelta the offset from the
* original position, in pixels
*/
LayoutDrag.prototype.getAdjustedPosition = function (pixelDelta) {
var gridDelta = toGridDelta(this.gridSize, pixelDelta);
return {
position: max(add(
this.rawPosition.position,
multiply(gridDelta, this.posFactor)
), [0, 0]),
dimensions: max(add(
this.rawPosition.dimensions,
multiply(gridDelta, this.dimFactor)
), [1, 1])
};
};
return LayoutDrag;
}
);