Files
iD/js/id/actions/join.js
2013-06-12 17:10:41 -07:00

114 lines
3.7 KiB
JavaScript

// Join ways at the end node they share.
//
// This is the inverse of `iD.actions.Split`.
//
// Reference:
// https://github.com/systemed/potlatch2/blob/master/net/systemeD/halcyon/connection/actions/MergeWaysAction.as
// https://github.com/openstreetmap/josm/blob/mirror/src/org/openstreetmap/josm/actions/CombineWayAction.java
//
iD.actions.Join = function(ids) {
function groupEntitiesByGeometry(graph) {
var entities = ids.map(function(id) { return graph.entity(id); });
return _.extend({line: []}, _.groupBy(entities, function(entity) { return entity.geometry(graph); }));
}
var action = function(graph) {
var existing = 0,
nodes,
a, b,
i, j;
function replaceWithA(parent) {
graph = graph.replace(parent.replaceMember(b, a));
}
// Prefer to keep an existing way.
for (i = 0; i < ids.length; i++) {
if (!graph.entity(ids[i]).isNew()) {
existing = i;
break;
}
}
// Join ways to 'a' in the following order: a-1, a-2, ..., 0, a+1, a+2, ..., ids.length-1
for (i = 0; i < ids.length; i++) {
j = (i <= existing) ? (existing - i) : i;
if (j === existing) {
continue;
}
a = graph.entity(ids[existing]);
b = graph.entity(ids[j]);
if (a.first() === b.first()) {
// a <-- b ==> c
// Expected result:
// a <-- b <-- c
b = iD.actions.Reverse(ids[j])(graph).entity(ids[j]);
nodes = b.nodes.slice().concat(a.nodes.slice(1));
} else if (a.first() === b.last()) {
// a <-- b <== c
// Expected result:
// a <-- b <-- c
nodes = b.nodes.concat(a.nodes.slice(1));
} else if (a.last() === b.first()) {
// a --> b ==> c
// Expected result:
// a --> b --> c
nodes = a.nodes.concat(b.nodes.slice(1));
} else if (a.last() === b.last()) {
// a --> b <== c
// Expected result:
// a --> b --> c
b = iD.actions.Reverse(ids[j])(graph).entity(ids[j]);
nodes = a.nodes.concat(b.nodes.slice().slice(1));
}
graph.parentRelations(b).forEach(replaceWithA);
graph = graph.replace(a.mergeTags(b.tags).update({ nodes: nodes }));
graph = iD.actions.DeleteWay(ids[j])(graph);
}
return graph;
};
action.disabled = function(graph) {
var geometries = groupEntitiesByGeometry(graph),
i;
// direction of the previous way -- the next way can join only on the opposite side than the previous joint
var prev_direction = 0;
if (ids.length < 2 || ids.length !== geometries.line.length)
return 'not_eligible';
for (i = 0; i+1 < ids.length; i++) {
var a = graph.entity(ids[i+0]),
b = graph.entity(ids[i+1]);
if (a.first() === b.first() && prev_direction <= 0) {
prev_direction = 1;
continue;
} else if (a.first() === b.last() && prev_direction <= 0) {
prev_direction = -1;
continue;
} else if (a.last() === b.first() && prev_direction >= 0) {
prev_direction = 1;
continue;
} else if (a.last() === b.last() && prev_direction >= 0) {
prev_direction = -1;
continue;
}
return 'not_adjacent';
}
};
return action;
};