chore(CI): add build for flatpak image

.travis.yml

@@ -103,16 +103,22 @@ matrix:
       cache:
         directories:
           - /opt/build-windows/x86_64
-    - stage: "macOS and AppImage"
+    - stage: "macOS, AppImage and Flatpak"
       os: osx
       osx_image: xcode7.3
       env: JOB=build-osx
-    - stage: "macOS and AppImage"
+    - stage: "macOS, AppImage and Flatpak"
       os: linux
       env: JOB=APPIMAGE
       script: ./appimage/build-appimage.sh
       services:
         - docker
+    - stage: "macOS, AppImage and Flatpak"
+      os: linux
+      env: JOB=FLATPAK
+      script: ./flatpak/build-flatpak.sh
+      services:
+        - docker
 
 script: "./.travis/$JOB.sh"
 

flatpak/build-flatpak.sh

@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+
+# SPDX-License-Identifier: GPL-3.0+
+#
+# Copyright © 2018 by The qTox Project Contributors
+#
+# This script should be run from the root of the repository
+
+if [ ! -f ./flatpak/build-flatpak.sh ]; then
+    echo ""
+    echo "You are attempting to run the build-flatpak.sh from a wrong directory."
+    echo "If you wish to run this script, you'll have to have"
+    echo "the repository root directory as the working directory."
+    echo ""
+    exit 1
+fi
+
+mkdir -p ./output
+
+docker run --rm --privileged \
+    -v $PWD:/qtox \
+    -v $PWD/output:/output \
+    debian:stretch-slim \
+    /bin/bash -c "/qtox/flatpak/build.sh"

flatpak/build.sh

@@ -0,0 +1,70 @@
+#!/usr/bin/env bash
+
+# SPDX-License-Identifier: GPL-3.0+
+#
+# Copyright © 2018 by The qTox Project Contributors
+
+# Fail out on error
+set -exuo pipefail
+
+# directory paths
+readonly QTOX_SRC_DIR="/qtox"
+readonly OUTPUT_DIR="/output"
+readonly BUILD_DIR="/build"
+readonly QTOX_BUILD_DIR="$BUILD_DIR"/qtox
+readonly FP_BUILD_DIR="$BUILD_DIR"/flatpak
+readonly APT_FLAGS="-y --no-install-recommends"
+# flatpak manifest file
+readonly QTOX_MANIFEST="https://raw.githubusercontent.com/flathub/io.github.qtox.qTox/master/io.github.qtox.qTox.json"
+# flatpak manifest download location
+readonly MANIFEST_FILE="flatpak/io.github.qtox.qTox.json"
+# directory containing necessary patches
+readonly PATCH_DIR="flatpak/patches"
+# use multiple cores when building
+export MAKEFLAGS="-j$(nproc)"
+
+# add backports repo, needed for a recent enough flatpak
+echo "deb http://ftp.debian.org/debian stretch-backports main" > /etc/apt/sources.list.d/stretch-backports.list
+
+# Get packages
+apt-get update
+apt-get install $APT_FLAGS ca-certificates git elfutils wget xz-utils patch
+
+# install recent flatpak packages
+apt-get install $APT_FLAGS -t stretch-backports flatpak flatpak-builder
+
+# create build directory
+mkdir -p "$BUILD_DIR"
+cd "$BUILD_DIR"
+
+# copy qtox source
+cp -r "$QTOX_SRC_DIR" "$QTOX_BUILD_DIR"
+cd "$QTOX_BUILD_DIR"
+
+# download manifest file if not in repo, this allows an easy local override
+if [ ! -f "$MANIFEST_FILE" ];
+then
+  wget -O "$MANIFEST_FILE" "$QTOX_MANIFEST"
+fi
+
+# build from the local build directory instead of the git repo
+patch "$MANIFEST_FILE" < "$PATCH_DIR"/build_directory.patch
+
+# this patch should contain all other patches needed
+patch "$MANIFEST_FILE" < "$PATCH_DIR"/ci_fixes.patch
+
+# create flatpak build directory
+mkdir -p "$FP_BUILD_DIR"
+cd "$FP_BUILD_DIR"
+
+# Add 'https://flathub.org' remote:
+flatpak remote-add --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
+
+# Build the qTox flatpak
+flatpak-builder --disable-rofiles-fuse --install-deps-from=flathub --force-clean --repo=tox-repo qTox-flatpak "$QTOX_BUILD_DIR"/flatpak/io.github.qtox.qTox.json
+
+# Create a bundle for distribution
+flatpak build-bundle tox-repo "$OUTPUT_DIR"/qtox.flatpak io.github.qtox.qTox
+
+# Chmod since everything is root:root
+chmod 755 -R "$OUTPUT_DIR"

flatpak/patches/build_directory.patch

@@ -0,0 +1,14 @@
+97,103c97,101
+< 				{
+< 					"type": "git",
+< 					"url": "https://github.com/qTox/qTox",
+< 					"tag": "v1.15.0", 
+< 					"commit": "02d6c63acaac0ae95fa8be3a1b9301657e6a4a94"
+< 				}
+< 			]
+---
+>                 {
+>                     "type": "dir",
+>                     "path": "/build/qtox/"
+>                 }
+>             ]

flatpak/patches/ci_fixes.patch

@@ -0,0 +1,3 @@
+8,9d7
+< 	"rename-desktop-file": "qtox.desktop",
+< 	"rename-appdata-file": "qTox.appdata.xml",