Build the unit tests using xvfb if available.

xvfb.disable=true will allow building without, even if xvfb is found.
Fixes issue 3422

Change-Id: I012bdfc694da10eac9a5afd1346841c4164ac386
Reviewed-on: http://gerrit.dmdirc.com/328
Reviewed-by: Shane Mc Cormack <shane@dmdirc.com>
Tested-by: Shane Mc Cormack <shane@dmdirc.com>

build-tests.xml

@@ -6,6 +6,7 @@
     <taskdef resource="cloverlib.xml" classpath="${clover.jar}"/>
     <taskdef resource="cloverjunitlib.xml" classpath="${clover.jar}"/>
     <available property="clover.installed" classname="com.cenqua.clover.CloverInstr" />
+    <available file="/usr/bin/xvfb-run" property="has.xvfb"/>
 
     <target name="with.clover" depends="clean" if="clover.installed"
             description="Set up Clover to instrument tests.">
@@ -57,6 +58,35 @@
         </junitreport>
     </target>
 
+    <target name="test" depends="check-use-xvfb, -test-xvfb, -test-no-xvfb"/>
+
+    <target name="check-use-xvfb">
+        <condition property="use.xvfb">
+            <and>
+                <not>
+                    <equals arg1="${xvfb.disable}" arg2="true" />
+                </not>
+                <equals arg1="${has.xvfb}" arg2="true" />
+            </and>
+        </condition>
+    </target>
+
+    <target name="-test-xvfb" if="use.xvfb">
+        <exec executable="/usr/bin/xvfb-run">
+            <arg value="-a"/>
+            <arg value="-s"/>
+            <arg value="-screen 0 1280x1024x24"/>
+            <arg value="-w"/>
+            <arg value="-5"/>
+            <arg value="/usr/bin/ant"/>
+            <arg value="do-real-test"/>
+        </exec>
+    </target>
+
+    <target name="-test-no-xvfb" unless="use.xvfb">
+        <antcall target="do-real-test"/>
+    </target>
+
     <target name="test-html" depends="with.clover,compile-test,test,clover.html,clover.snapshot"
             description="Run tests and generate a Clover HTML report."/>
     <target name="test-xml" depends="with.clover,compile-test,test,clover.xml,clover.snapshot"

nbproject/build-impl.xml

@@ -650,7 +650,7 @@ is divided into following sections:
     </target>
     <target depends="init" if="have.tests" name="test-report"/>
     <target depends="init" if="netbeans.home+have.tests" name="-test-browse"/>
-    <target depends="init,compile-test,-pre-test-run,-do-test-run,test-report,-post-test-run,-test-browse" description="Run unit tests." name="test"/>
+    <target depends="init,compile-test,-pre-test-run,-do-test-run,test-report,-post-test-run,-test-browse" description="Run unit tests." name="do-real-test"/>
     <target depends="init" if="have.tests" name="-pre-test-run-single">
         <mkdir dir="${build.test.results.dir}"/>
     </target>