doc: add some more text protocol documentation

Signed-off-by: Jan Arne Petersen <jpetersen@openismus.com>

protocol/text.xml

@@ -145,6 +145,8 @@
         to commit could be either just a single character after a key press
         or the result of some composing (pre-edit). It also sets the new
         cursor position (as byte index) relative to the inserted text.
+
+        Any previously set composing text should be removed.
       </description>
       <arg name="serial" type="uint"/>
       <arg name="text" type="string"/>
@@ -154,8 +156,10 @@
       <description summary="pre-edit">
         Notify when a new composing text (pre-edit) should be set around the
         current cursor position. Any previously set composing text should
-        be removed. It also sets the cursor position (as byte index) relative
+        be removed.
-        to the start of the composing text.
+
+        The commit text can be used to replace the preedit text on reset
+        (for example on unfocus).
       </description>
       <arg name="serial" type="uint"/>
       <arg name="text" type="string"/>
@@ -181,6 +185,15 @@
       <entry name="incorrect" value="7"/>
     </enum>
     <event name="preedit_styling">
+      <description summary="pre-edit styling">
+        Sets styling information on composing text. The style is applied for
+        length (in bytes) characters from index relative to the beginning of
+        the composing text (as byte index). Multiple styles can be applied
+        to a composing text.
+
+        This event should be handled as part of a following preedit_string
+        event.
+      </description>
       <arg name="serial" type="uint"/>
       <arg name="index" type="uint"/>
       <arg name="length" type="uint"/>
@@ -190,6 +203,9 @@
       <description summary="pre-edit cursor">
         Sets the cursor position inside the composing text (as byte index)
         relative to the start of the composing text.
+
+        This event should be handled as part of a following preedit_string
+        event.
       </description>
       <arg name="serial" type="uint"/>
       <arg name="index" type="int"/>