Add documentation for <native-messaging> capability

Author: bastianeicher

docs/specifications/app-list.xsd

@@ -68,6 +68,7 @@
       <xsd:element name="desktop-icon" type="apps:desktop-icon" />
       <xsd:element name="quick-launch" type="apps:quick-launch" />
       <xsd:element name="url-protocol" type="apps:url-protocol" />
+      <xsd:element name="native-messaging" type="apps:native-messaging" />
       <xsd:element name="auto-play" type="apps:auto-play" />
       <xsd:element name="context-menu" type="apps:context-menu" />
       <xsd:element name="default-program" type="apps:default-program" />
@@ -145,6 +146,14 @@
       <xsd:extension base="apps:default-access-point" />
     </xsd:complexContent>
   </xsd:complexType>
+  <xsd:complexType name="native-messaging">
+    <xsd:annotation>
+      <xsd:documentation>Makes an application a browser native messaging host.</xsd:documentation>
+    </xsd:annotation>
+    <xsd:complexContent>
+      <xsd:extension base="apps:default-access-point" />
+    </xsd:complexContent>
+  </xsd:complexType>
   <xsd:complexType name="command-access-point" abstract="true">
     <xsd:annotation>
       <xsd:documentation>Adds a way to explicitly launch the application to the desktop environment.</xsd:documentation>

docs/specifications/capabilities.md

@@ -114,6 +114,36 @@ See: [Verbs](#verbs), [Icons](#icons)
 - a single `<verb>`: creates a simple context menu, named using the `<description>` inside `<verb>`
 - multiple `<verb>`s (since version 2.18): creates a cascading context menu, named using the `<description>` inside `<context-menu>`, with sub-entries named using the `<description>` inside `<verb>`
 
+### Browser native messaging
+
+An application's ability to act as a browser native messaging host.
+
+```xml
+<native-messaging id='...' browser='...' name='...' command='...' ? explicit-only='true' ?>
+  <browser-extension id='...'/> *
+</native-messaging>
+```
+
+`id`
+: An ID that uniquely identifies this native messaging entry within the feed. Must be a [safe ID](#safe-id).
+
+`browser`
+: The browser the native messaging host can be registered in.  
+  Supported values are: `Chrome`, `Chromium`, `Edge`, `Firefox`, `Opera`, `Brave`, `Vivaldi`
+
+`name`
+: The name used to call the native messaging host from browser extensions.  
+  Can only contain lowercase alphanumeric characters, underscores (`_`) and dots (`.`). Can't start or end with a dot, and a dot can't be followed by another dot.
+
+`command`
+: The name of the command in the feed to use. Defaults to `run` if not set.
+
+`explicit-only`
+: When set to `true` this context menu entry is not added without explicit confirmation from the user.
+
+`<browser-extension>`
+: Browser extension that should have access to the native messaging host.
+
 ### AutoPlay handlers
 
 An application's ability to handle AutoPlay events. 

docs/specifications/capabilities.xsd

@@ -21,6 +21,7 @@
       <xs:element name="file-type" type="caps:file-type" />
       <xs:element name="url-protocol" type="caps:url-protocol" />
       <xs:element name="context-menu" type="caps:context-menu" />
+      <xs:element name="native-messaging" type="caps:native-messaging" />
       <xs:element name="auto-play" type="caps:auto-play" />
       <xs:element name="com-server" type="caps:com-server" />
       <xs:element name="registration" type="caps:registration" />
@@ -308,6 +309,68 @@
     </xs:restriction>
   </xs:simpleType>
 
+  <xs:complexType name="native-messaging">
+    <xs:annotation>
+      <xs:documentation>
+        An application's ability to act as a browser native messaging host.
+      </xs:documentation>
+    </xs:annotation>
+    <xs:complexContent>
+      <xs:extension base="caps:default-capability">
+        <xs:attribute name="browser" type="caps:browser-enum" use="required">
+          <xs:annotation>
+            <xs:documentation>
+              The browser the native messaging host can be registered in.
+            </xs:documentation>
+          </xs:annotation>
+        </xs:attribute>
+        <xs:attribute name="name" type="caps:native-messaging-name" use="required">
+          <xs:annotation>
+            <xs:documentation>
+              The name used to call the native messaging host from browser extensions.
+            </xs:documentation>
+          </xs:annotation>
+        </xs:attribute>
+        <xs:attribute name="command" type="xs:string">
+          <xs:annotation>
+            <xs:documentation>
+              The name of the command in the feed to use. Defaults to 'run' if not set.
+            </xs:documentation>
+          </xs:annotation>
+        </xs:attribute>
+        <xs:sequence>
+          <xs:element name="browser-extension" minOccurs="1" maxOccurs="unbounded">
+            <xs:complexType>
+              <xs:attribute name="id" type="xs:string" use="required">
+                <xs:annotation>
+                  <xs:documentation>
+                    Browser extension that should have access to the native messaging host.
+                  </xs:documentation>
+                </xs:annotation>
+              </xs:attribute>
+            </xs:complexType>
+          </xs:element>
+        </xs:sequence>
+      </xs:extension>
+    </xs:complexContent>
+  </xs:complexType>
+  <xs:simpleType name="browser-enum">
+    <xs:restriction base="xs:string">
+      <xs:enumeration value="Chrome"/>
+      <xs:enumeration value="Chromium"/>
+      <xs:enumeration value="Edge"/>
+      <xs:enumeration value="Firefox"/>
+      <xs:enumeration value="Opera"/>
+      <xs:enumeration value="Brave"/>
+      <xs:enumeration value="Vivaldi"/>
+    </xs:restriction>
+  </xs:simpleType>
+  <xs:simpleType name="native-messaging-name">
+    <xs:restriction base="xs:string">
+      <xs:pattern value="[a-z0-9._]+"/>
+    </xs:restriction>
+  </xs:simpleType>
+
   <xs:complexType name="auto-play">
     <xs:annotation>
       <xs:documentation>