203 lines
8.5 KiB
JavaScript

/*****************************************************************************
* Open MCT, Copyright (c) 2014-2016, United States Government
* as represented by the Administrator of the National Aeronautics and Space
* Administration. All rights reserved.
*
* Open MCT 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 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.
*****************************************************************************/
/**
* Module defining TreeNodeController. Created by vwoeltje on 11/10/14.
*/
define(
[],
function () {
/**
* The TreeNodeController supports the tree node representation;
* a tree node has a label for the current object as well as a
* subtree which shows (and is not loaded until) the node is
* expanded.
*
* This controller tracks the following, so that the tree node
* template may update its state accordingly:
*
* * Whether or not the tree node has ever been expanded (this
* is used to lazily load, exactly once, the subtree)
* * Whether or not the node is currently the domain object
* of navigation (this gets highlighted differently to
* provide the user with visual feedback.)
*
* Additionally, this controller will automatically trigger
* node expansion when this tree node's _subtree_ will contain
* the navigated object (recursively, this becomes an
* expand-to-show-navigated-object behavior.)
*
* Finally, if a `callback` property is passed in through the
* `parameters` attribute of the `tree-node`, that callback
* will be invoked whenever a user clicks in a manner which
* would result in a selection. This callback is invoked
* even if the selection does not change (if you are only
* interested in changes, watch the `selectedObject` property
* of the object passed in `ng-model` instead.)
*
* @memberof platform/commonUI/general
* @constructor
*/
function TreeNodeController($scope, $timeout) {
var self = this,
selectedObject = ($scope.ngModel || {}).selectedObject;
// Look up the id for a domain object. A convenience
// for mapping; additionally does some undefined-checking.
function getId(obj) {
return obj && obj.getId && obj.getId();
}
// Verify that id paths are equivalent, staring at
// index, ending at the end of the node path.
function checkPath(nodePath, navPath, index) {
index = index || 0;
// The paths overlap if we have made it past the
// end of the node's path; otherwise, check the
// id at the current index for equality and perform
// a recursive step for subsequent ids in the paths,
// until we exceed path length or hit a mismatch.
return (index >= nodePath.length) ||
((navPath[index] === nodePath[index]) &&
checkPath(nodePath, navPath, index + 1));
}
// Consider the currently-navigated object and update
// parameters which support display.
function checkSelection() {
var nodeObject = $scope.domainObject,
navObject = selectedObject,
nodeContext = nodeObject &&
nodeObject.getCapability('context'),
navContext = navObject &&
navObject.getCapability('context'),
nodePath,
navPath;
// Deselect; we will reselect below, iff we are
// exactly at the end of the path.
self.isSelectedFlag = false;
// Expand if necessary (if the navigated object will
// be in this node's subtree)
if (nodeContext && navContext) {
// Get the paths as arrays of identifiers
nodePath = nodeContext.getPath().map(getId);
navPath = navContext.getPath().map(getId);
// Check to see if the node's path lies entirely
// within the navigation path; otherwise, navigation
// has happened in some other subtree.
if (navPath.length >= nodePath.length &&
checkPath(nodePath, navPath)) {
// nodePath is along the navPath; if it's
// at the end of the path, highlight;
// otherwise, expand.
if (nodePath.length === navPath.length) {
self.isSelectedFlag = true;
} else { // node path is shorter: Expand!
if ($scope.toggle) {
$scope.toggle.setState(true);
}
self.trackExpansion();
}
}
}
}
// Callback for the selection updates; track the currently
// navigated object and update display parameters as needed.
function setSelection(object) {
selectedObject = object;
checkSelection();
}
this.isSelectedFlag = false;
this.hasBeenExpandedFlag = false;
this.$timeout = $timeout;
this.$scope = $scope;
// Listen for changes which will effect display parameters
$scope.$watch("ngModel.selectedObject", setSelection);
$scope.$watch("domainObject", checkSelection);
}
/**
* Select the domain object represented by this node in the tree.
* This will both update the `selectedObject` property in
* the object passed in via `ng-model`, and will fire any `callback`
* passed in via `parameters`.
*/
TreeNodeController.prototype.select = function () {
if (this.$scope.ngModel) {
this.$scope.ngModel.selectedObject =
this.$scope.domainObject;
}
if ((this.$scope.parameters || {}).callback) {
this.$scope.parameters.callback(this.$scope.domainObject);
}
};
/**
* This method should be called when a node is expanded
* to record that this has occurred, to support one-time
* lazy loading of the node's subtree.
*/
TreeNodeController.prototype.trackExpansion = function () {
var self = this;
if (!self.hasBeenExpanded()) {
// Run on a timeout; if a lot of expansion needs to
// occur (e.g. if the selection is several nodes deep) we
// want this to be spread across multiple digest cycles.
self.$timeout(function () {
self.hasBeenExpandedFlag = true;
}, 0);
}
};
/**
* Check if this not has ever been expanded.
* @returns true if it has been expanded
*/
TreeNodeController.prototype.hasBeenExpanded = function () {
return this.hasBeenExpandedFlag;
};
/**
* Check whether or not the domain object represented by
* this tree node should be highlighted.
* An object will be highlighted if it matches
* ngModel.selectedObject
* @returns true if this should be highlighted
*/
TreeNodeController.prototype.isSelected = function () {
return this.isSelectedFlag;
};
return TreeNodeController;
}
);