Difference between revisions of "Map Annotation"
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Revision as of 17:47, 22 January 2013
This page provides information about interactive annotation of the University Map. If you are interested in scripting or programming overlays from other data sets, see the UCamGeoJSON API.
Note: if all you want to do is create a link to show your department etc on the map, you don't need to create any annotation. Just use the link shown in your browser address bar when you are looking at the full results for the institution. For example: http://map.cam.ac.uk/Department+of+Geography . This also means if you move, the link will show up-to-date information without any changes.
Also if you only want a single pin on the map, you can do this directly from the map: click where you want it and choose the pin icon. Then copy the URL from the browser address bar.
This page deals with more substantial annotations.
It is useful to be able to customize the University Map. This might be for
- something ephemeral, like emailing directions or highlighting a meeting place to someone;
- something semi-permanent such as locations of a series of events around the University (for example, consider the Cambridge Shakespeare Festival, or Science Week);
- something permanent, such as more detail or special interest information (for example, consider disability information, college staircase locations, college meeting rooms, or the Granta Backbone Network).
This is achieved by referencing in the map URL a set of annotations stored at a another URL somewhere on the internet. This could be
- temporary storage provided by the map server itself,
- your personal University web pages,
- a departmental website,
- a shared Dropbox file (or other cloud service)
- anywhere, really, subject to certain security limitations
This URL is given in the fragment part of the map URL, that is, the bit after a hash sign '#', like this
The link provides a set of data in UCamGeoJSON format. This can be generated programatically where you have a geographically-minded data set to display, but for more casual use interactive Map Annotation, in effect to draw on top of the map and then save your annotations for other people to refer to.
Annotate Map on the More link of the main map takes you to the map annotation page. This provides a web app where you can draw onto the map and then save the drawing for other people to see, by providing a link on a web page or sending them a link by email, and so on.
A set of annotations comprises one or more features, which are independent from each other, and layered so that if they overlap one will draw on top of another. You can draw three different kinds of feature: points (to which images and text can be attached), lines and areas.
Points represent real geographical locations, so as you zoom out they get close together visually. However, images and text applied to a point are fixed size: they do not scale up and down as the map is scaled, so they may overlap at larger scales.
Adding points, lines and areas
If you make a mistake at any time, you can use the Undo button (or the CTRL+Z key) to reverse your change.
Click on the map to make a point. This is shown with a small red mark called a handle. When you have more than one handle, only one can be red, indicating that it is selected, that is, identifying the point and feature to which changes will be made. The others are green. Select a handle by clicking on it. Clicking on the already selected handle will deselect it.
Having made a point, you can now either can add a second point to start drawing a line, or apply text and/or an image to the single point.
To help you see where a line will go, a putative 'rubber band' line is connected from the selected point. This will go away if you add an image or text, but if it bothers you, press the ESC key to explicitly turn off line formation.
Once a single point is selected (which it will be immediately after you have made one), the left hand side panel changes to offer a form where you can add images, text, colour, borders etc. to the point. Details below.
If instead you make a line the panel changes to offer properties for the line, such as width and colour. Click again to add further points to the line. You can also extend an existing line from either end by clicking on the first or last point.
Once you have at least three points, you can form a closed area by clicking on the first point. If you cancel the rubber-band line with ESC, clicking the first point will just select it, and therefore offer to extend it from the other end.
Changing existing features
Move a point by dragging its handle. You can either re-position a decorated single point, or change the shape of a line or area by moving one of its vertices.
You can also move the whole of a line or area by dragging starting anywhere within in its bounding rectangle.
The menus provide means to change existing features. Naturally, the Features menu offers things you can do to features as a whole, and the Points menu things you can do to points.
- Delete Feature deletes the complete feature containing a selected point.
- Bring To Front and Send To Back change the order of the feature containing a selected point in the layers, affecting how they appear when they overlap (and also which feature you would be able to drag around to move it: if features overlap, the one on top will be the one that is moved).
- Duplicate Feature to make a copy of the feature containing a selected point, slightly offset from the original
- To start over with no features, use Clear All on the Data menu. (If you accidentally delete everything with this, you can Undo it).
These apply only to points in areas and lines.
- Insert Point adds a new point half way along the line segment of a line or edge of an area which precedes the selected point. Once you have inserted a point, you can move it to where you want it by dragging in the usual way.
- You may well have forgotten which way round the points go. Notice the point before the selected point is a lighter shade of green. The new point goes between the selected point and the lighter green point.
- Remove Point removes the selected point. You can only remove a point from an area with more than three points or a line with more than two.
Fill in the boxes and use the menus etc in the left hand panel to change the appearance of the feature you have selected.
With nothing selected (deselect any selected point by clicking on it) you can set a heading for the whole page. The recipients of your annotations will see this in the same style as the headline in the left hand panel as shown while annotating.