odoo-survey-addons/custom_matrix_survey/views/survey_views.xml

<?xml version="1.0" encoding="utf-8"?>
<odoo>
   	<record model="ir.ui.view" id="survey_question_custom_form">
            <field name="name">Form view for survey custom question</field>
            <field name="model">survey.question</field>
            <field name="inherit_id" ref="survey.survey_question_form"/>
            <field name="arch" type="xml">
                <xpath expr="//notebook//page//field[@name='labels_ids']//tree" position="inside">
                    <field name="type"/>
                    <field name="dpvalues" widget="many2many_tags" attrs="{'invisible': [('type', '!=', 'dropdown')]}"/>
                </xpath>
            </field>
    </record>

    <record model="ir.ui.view" id="survey_user_input_line_custom_form">
            <field name="name">survey_user_input_line_custom_form</field>
            <field name="model">survey.user_input_line</field>
            <field name="inherit_id" ref="survey.survey_user_input_line_form"/>
            <field name="arch" type="xml">
                <field name="value_text" position="after">
                    <field name="value_dropdown" attrs="{'invisible': [('answer_type','!=','dropdown')]}"/>
                    <field name="matrix_subtype_id"/>
                </field>
                <field name="value_suggested" position="replace">
                    <field name="value_suggested" colspan='2' attrs="{'invisible': [ ('answer_type','!=','suggestion'), ('matrix_subtype_id', '!=', 'custom_row')]}"/>
                </field>
            </field>
    </record>
    <report 
            id="action_view_pdf_answers"
            string="Answers"
            model="survey.user_input" 
            report_type="qweb-pdf"
            file="custom_matrix_survey.report_survey_answers" 
            name="custom_matrix_survey.report_survey_answers"
            print_report_name="'answer - %s' % (object.survey_id.title)"
        />

    <record model="ir.ui.view" id="survey_user_input_custom_form">
            <field name="name">survey_user_input_custom_form</field>
            <field name="model">survey.user_input</field>
            <field name="inherit_id" ref="survey.survey_user_input_form"/>
            <field name="arch" type="xml">
                <xpath expr="//form//header//button[@name='action_view_answers']" position="after">
                    <button name="%(action_view_pdf_answers)d" states="done" string="Print PDF Answers" type="action"  class="oe_highlight" />
                </xpath>
            </field>
    </record>
</odoo>