odoo_source/addons/mail/views/mail_activity_views.xml

<?xml version="1.0"?>
<odoo>
    <record id="mail_activity_type_view_form" model="ir.ui.view">
        <field name="name">mail.activity.type.view.form</field>
        <field name="model">mail.activity.type</field>
        <field name="arch" type="xml">
            <form string="Activities">
                <sheet>
                    <div class="oe_title">
                        <label for="name" class="oe_edit_only"/>
                        <h1><field name="name"/></h1>
                    </div>
                    <group>
                        <group>
                            <field name="res_model_id" groups="base.group_no_one"/>
                            <field name="icon" groups="base.group_no_one"/>
                            <field name="days"/>
                        </group>
                        <group>
                            <field name="summary"/>
                        </group>
                    </group>
                </sheet>
            </form>
        </field>
    </record>

    <record id="mail_activity_type_view_tree" model="ir.ui.view">
        <field name="name">mail.activity.type.view.tree</field>
        <field name="model">mail.activity.type</field>
        <field name="arch" type="xml">
            <tree string="Activities">
                <field name="sequence" widget="handle"/>
                <field name="name"/>
                <field name="summary"/>
                <field name="days"/>
                <field name="res_model_id" groups="base.group_no_one"/>
                <field name="icon" groups="base.group_no_one"/>
            </tree>
        </field>
    </record>

    <record id="mail_activity_type_action" model="ir.actions.act_window">
        <field name="name">Activity Types</field>
        <field name="res_model">mail.activity.type</field>
        <field name="view_type">form</field>
        <field name="view_mode">tree,form</field>
    </record>

    <menuitem
      id="menu_mail_activity_type"
      action="mail_activity_type_action"
      parent="base.menu_email"
    />

    <record id="mail_activity_view_form_popup" model="ir.ui.view">
        <field name="name">mail.activity.view.form.popup</field>
        <field name="model">mail.activity</field>
        <field name="priority">20</field>
        <field name="arch" type="xml">
            <form string="Log an Activity" create="false">
                <sheet string="Activity">
                    <group>
                        <field name="res_model" invisible="1"/>
                        <field name="res_model_id" invisible="1"/>
                        <field name="res_id" invisible="1"/>
                        <group>
                            <field name="activity_type_id" required="1" options="{'no_create': True, 'no_open': True}"/>
                            <field name="summary" placeholder="e.g. Discuss proposal"/>
                        </group>
                        <group>
                            <field name="date_deadline"/>
                            <field name="user_id"/>
                        </group>
                    </group>
                    <field name="note" placeholder="Log a note..."/>
                    <footer>
                        <button string="Schedule" name="action_close_dialog"
                            type="object" class="btn-primary"/>
                        <button string="Mark as Done" name="action_done"
                            type="object" class="btn-primary"/>
                        <button string="Discard" class="btn-default" special="cancel" />
                    </footer>
                </sheet>
            </form>
        </field>
    </record>

    <record id="mail_activity_view_search" model="ir.ui.view">
        <field name="name">mail.activity.view.search</field>
        <field name="model">mail.activity</field>
        <field name="arch" type="xml">
            <search string="Activity">
                <field name="res_model_id"/>
                <field name="summary"/>
                <field name="activity_type_id"/>
                <separator/>
                <filter string="My Activities" name="activities_my"
                        domain="[('create_uid', '=', uid)]"/>
                <filter string="Today Activities" name="activities_today"
                        domain="[('date_deadline', '=', context_today().strftime('%Y-%m-%d'))]"/>
                <filter string="Upcoming Activities (7 days)" name="activities_week"
                        domain="['&amp;', ('date_deadline', '&gt;=', context_today().strftime('%Y-%m-%d')),
                                 ('date_deadline', '&lt;=', (context_today()+datetime.timedelta(days=7)).strftime('%Y-%m-%d'))
                        ]"/>
                <filter string="Overdue Activities" name="activities_overdue"
                        domain="[('date_deadline', '&lt;', context_today().strftime('%Y-%m-%d'))]"
                        help="Show all records which has next action date is before today"/>
                <separator/>
                <group expand="0" string="Group By">
                    <filter string="Deadline" context="{'group_by': 'date_deadline'}"/>
                    <filter string="Created By" context="{'group_by': 'create_uid'}"/>
                    <filter string="Activity Type" context="{'group_by': 'activity_type_id'}"/>
                </group>
            </search>
        </field>
    </record>

    <record id="mail_activity_view_tree" model="ir.ui.view">
        <field name="name">mail.activity.view.tree</field>
        <field name="model">mail.activity</field>
        <field name="arch" type="xml">
            <tree string="Next Activities"
                    decoration-danger="date_deadline &lt; current_date"
                    decoration-success="date_deadline == current_date"
                    default_order="date_deadline" create="false">
                <field name="res_name"/>
                <field name="activity_type_id"/>
                <field name="summary"/>
                <field name="date_deadline"/>
            </tree>
        </field>
    </record>

    <record id="mail_activity_view_calendar" model="ir.ui.view">
        <field name="name">mail.activity.view.calendar</field>
        <field name="model">mail.activity</field>
        <field name="priority" eval="2"/>
        <field name="arch" type="xml">
            <calendar string="Activity" date_start="date_deadline" color="activity_type_id">
                <field name="res_name"/>
                <field name="create_uid"/>
                <field name="summary"/>
            </calendar>
        </field>
    </record>

</odoo>