build-system: Subsurface-mobile now requires Qt 5.11

This is one of the side effects of switching to Kirigami 5.62 - but since
we build our mobile versions with Qt 5.12 and Qt 5.13, this really isn't
an issue.

Signed-off-by: Dirk Hohndel <dirk@hohndel.org>

.travis.yml

@@ -75,48 +75,6 @@ matrix:
       services:
           - docker
 
-    - env: SUBSURFACE_PLATFORM='linux2'
-      os: linux
-      dist: trusty
-      language: c++
-      addons:
-        apt:
-          sources:
-            - sourceline: 'ppa:beineri/opt-qt-5.10.1-trusty'
-              key_url: 'https://keyserver.ubuntu.com/pks/lookup?op=get&search=0x10C56D0DE9977759'
-            - ubuntu-toolchain-r-test
-          packages:
-            - qt510base
-            - qt510connectivity
-            - qt510declarative
-            - qt510location
-            - qt510quickcontrols
-            - qt510quickcontrols2
-            - qt510script
-            - qt510translations
-            - qt510svg
-            - qt510tools
-            - git
-            - gcc-5
-            - g++-5
-            - make
-            - autoconf
-            - automake
-            - libtool
-            - cmake
-            - pkg-config
-            - libxml2-dev
-            - libxslt1-dev
-            - libzip-dev
-            - libsqlite3-dev
-            - libusb-1.0-0-dev
-            - libssl-dev
-            - libssh2-1-dev
-            - libcurl4-openssl-dev
-            # Not a subsurface dependency, but a Qt dependency
-            - mesa-common-dev
-            - libxcb-xinerama0
-
     - env: SUBSURFACE_PLATFORM="android"
       # Currently hard coded to arm
       os: linux

CMakeLists.txt

@@ -243,7 +243,12 @@ if(ANDROID)
 	set(CMAKE_FIND_ROOT_PATH "/;${CMAKE_FIND_ROOT_PATH}")
 endif()
 set(QT_FIND_COMPONENTS Core Concurrent Widgets Network Svg Positioning Quick Location ${QT_EXTRA_COMPONENTS})
-find_package(Qt5 5.9.1 REQUIRED COMPONENTS ${QT_FIND_COMPONENTS} LinguistTools Test QuickTest)
+if (SUBSURFACE_TARGET_EXECUTABLE MATCHES "DesktopExecutable")
+	find_package(Qt5 5.9.1 REQUIRED COMPONENTS ${QT_FIND_COMPONENTS} LinguistTools Test QuickTest)
+else()
+	# Kirigami 5.62 and newer require at least Qt 5.11
+	find_package(Qt5 5.11 REQUIRED COMPONENTS ${QT_FIND_COMPONENTS} LinguistTools Test QuickTest)
+endif()
 foreach(_QT_COMPONENT ${QT_FIND_COMPONENTS})
 	list(APPEND QT_LIBRARIES Qt5::${_QT_COMPONENT})
 endforeach()