Package org.exoplatform.caldav.utils

Class CalendarPalette

java.lang.Object

org.exoplatform.caldav.utils.CalendarPalette

public final class CalendarPalette
extends Object

Gives every remote calendar a colour, deterministically.

A port of the browser connector's derivation, arithmetic included, because the colour is what a user recognises a calendar by. Changing it would silently repaint everyone's agenda on the day this ships — the same events, the same calendars, different colours, with nothing to explain it.

The server's own colour wins when it publishes one. Only when it does not is a colour derived, from the collection path rather than from its position in a listing: a calendar added or removed elsewhere must not shift the colours of the others.

Method Summary

Modifier and Type	Method	Description
static String	colourOf(String publishedColour, String href, int position, int total)	The colour a calendar is shown in.
static List<String>	inStableOrder(List<String> hrefs)	The calendars in the order colours are derived from, which is not the order a server happens to list them in.
static String	normalise(String value)	A published colour reduced to the form eXo uses, or null when it is not a colour at all.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Details

inStableOrder

public static List<String> inStableOrder(List<String> hrefs)

The calendars in the order colours are derived from, which is not the order a server happens to list them in.

Sorted by href so that a position is a property of the account rather than of one response: a server free to reorder its listing would otherwise repaint the calendars between two reads.

Parameters:

hrefs - the collection hrefs

Returns:

the same hrefs, in a stable order

colourOf

public static String colourOf(String publishedColour,
 String href,
 int position,
 int total)

The colour a calendar is shown in.

Parameters:

publishedColour - what the server published, possibly absent

href - the collection href

position - the calendar's index in the stable order

total - how many calendars the account holds

Returns:

a hex colour that is always usable

normalise

public static String normalise(String value)

A published colour reduced to the form eXo uses, or null when it is not a colour at all.

Parameters:

value - what the server published

Returns:

#RRGGBB upper case, or null