Ring identifiers

There are many identifiers in Ring. We need to unify the naming of these identifiers between all implementations. This page reference various kind of identifiers used in Ring with relevant examples.

• Ring Infohash or Ring public key fingerprint : a public key fingerprint such as 3d1112ab2bb089370c0744a44bbbb0786418d40b
• Registered name : a username associated to a Ring Infohash on the blockchain such as jeandupont
• URI : a Ring or SIP URI such as ring:3d1112ab2bb089370c0744a44bbbb0786418d40b or ring:jeandupont or <sip:nnnnn@host:5060>. Must be compliant with rfc3986. If it's a SIP URI, it must be compliant with rfc3261#19.1.
• Canonical URI : ring:3d1112ab2bb089370c0744a44bbbb0786418d40b or sip:nnnnn@host:5060. The most simplified form of the URI. Registered name must be resolved, doesn't include <> brackets or display name. Prefixed with the scheme (ring: or sip: or sips:).
• RingID: registered name (preferred) or public key fingerprint. Unique identifier for a public key.
• Display name or Profile name : an editable user-defined profile name such as Jean Dupont.

When displaying a contact:

 _____
|photo|   Display name or RingID
|_____|   RingID

• If Display name is empty, RingID is shown instead
• If both lines have the same content, only the first line is displayed
• If no photo is available and a registered name (ring) or display name (sip) is available, the first letter of this name can be used to generate a placeholder. Otherwise a generic placeholder is used.
• If no photo is available, a placeholder with an Canonical URI-specific background color can be used:

final int[] contactColors = {
    color.red_500, color.pink_500,
    color.purple_500, color.deep_purple_500,
    color.indigo_500, color.blue_500,
    color.cyan_500, color.teal_500,
    color.green_500, color.light_green_500,
    color.grey_500, color.lime_500,
    color.amber_500, color.deep_orange_500,
    color.brown_500, color.blue_grey_500
};

int generateAvatarColor(String canonicalUri) {
    if (isEmpty(canonicalUri))
        return R.color.grey_500;
    String h = md5(canonicalUri);
    if (h == null)
        return R.color.grey_500;
    int colorIndex = Integer.parseInt(h.charAt(0) + "", 16);
    return contactColors[colorIndex % contactColors.length];
}

Color values are from the material palette: https://material.io/tools/color