In the JSON output, there is a field "maneuver" within a "step". In this "turn-left", "turn-right", "turn-slight-left", etc. Example is here
Where could I find the definition of the "maneuver" field, and the list of possible values? There is no relevant description here
Thanks in advance
Here is a visual for the lazy ones :)
Can't believe google did not document this yet...
UPD
Believe it or not, but finally they documented it! Please see here.
according to this gmaps-api-issue I think google not in hurry to document this part of api :(
But I can help with this issue at least with following... The "maneuver" field is the short description of step's action. I suppose google's script uses it for applying css classes to direction panel. I noticed that icon for each step depends on css class ".adp-{maneuver_name}". Css file for panel contains 18 classes with that mask and I had extracted list of maneuvers:
- turn-sharp-left
- uturn-right
- turn-slight-right
- merge
- roundabout-left
- roundabout-right
- uturn-left
- turn-slight-left
- turn-left
- ramp-right
- turn-right
- fork-right
- straight
- fork-left
- ferry-train
- turn-sharp-right
- ramp-left
- ferry
During the work I found two additional values of the "maneuver" field, which doesn't have css classes:
- keep-left
- keep-right
I can't guarantee fullness of this list, but I used this list in my project and it works properly.
when you use directions service, google maps inject some css in your <head>
As of 2015/jun, I've got this code below. It seems google only downloads what it needs to show the directions, so, your results may vary.
Background-image file at the bottom:
.adp-substep .adp-stepicon .adp-maneuver {
background-size: 19px 630px;
position: absolute;
left: 0;
width: 16px;
height: 16px
}
.adp-substep .adp-stepicon .adp-maneuver.adp-ferry {
background-position: 0 -614px
}
.adp-substep .adp-stepicon .adp-maneuver.adp-ferry-train {
background-position: 0 -566px
}
.adp-substep .adp-stepicon .adp-maneuver.adp-merge {
background-position: 0 -143px
}
.adp-substep .adp-stepicon .adp-maneuver.adp-straight {
background-position: 0 -534px
}
.adp-substep .adp-stepicon .adp-maneuver.adp-fork-left {
background-position: 0 -550px
}
.adp-substep .adp-stepicon .adp-maneuver.adp-ramp-left {
background-position: 0 -598px
}
.adp-substep .adp-stepicon .adp-maneuver.adp-roundabout-left {
background-position: 0 -197px
}
.adp-substep .adp-stepicon .adp-maneuver.adp-turn-left {
background-position: 0 -413px
}
.adp-substep .adp-stepicon .adp-maneuver.adp-turn-sharp-left {
background-position: 0 0
}
.adp-substep .adp-stepicon .adp-maneuver.adp-turn-slight-left {
background-position: 0 -378px
}
.adp-substep .adp-stepicon .adp-maneuver.adp-uturn-left {
background-position: 0 -305px
}
.adp-substep .adp-stepicon .adp-maneuver.adp-fork-right {
background-position: 0 -499px
}
.adp-substep .adp-stepicon .adp-maneuver.adp-ramp-right {
background-position: 0 -429px
}
.adp-substep .adp-stepicon .adp-maneuver.adp-roundabout-right {
background-position: 0 -232px
}
.adp-substep .adp-stepicon .adp-maneuver.adp-turn-right {
background-position: 0 -483px
}
.adp-substep .adp-stepicon .adp-maneuver.adp-turn-sharp-right {
background-position: 0 -582px
}
.adp-substep .adp-stepicon .adp-maneuver.adp-turn-slight-right {
background-position: 0 -51px
}
.adp-substep .adp-stepicon .adp-maneuver.adp-uturn-right {
background-position: 0 -35px
}
.adp-substep .adp-stepicon .adp-maneuver {
background-image: url(http://maps.gstatic.com/mapfiles/api-3/images/maneuvers.png);
}
Maneuver contains the action to take for the current step (turn left, merge, straight, etc.). This field is used to determine which icon to display, and can contain one of the following values: turn-slight-left, turn-sharp-left, uturn-left, turn-left, turn-slight-right, turn-sharp-right, uturn-right, turn-right, straight, ramp-left, ramp-right, merge, fork-left, fork-right, ferry, ferry-train, roundabout-left, roundabout-right. Values in this list are subject to change
Below link will help you to find all the images https://github.com/opentripplanner/OpenTripPlanner/tree/master/src/client/images/directions
来源：https://stackoverflow.com/questions/17941812/google-directions-api