initial gitpod configuration

* setup and building
* x11 config allowing to preview the GUI

.gitpod.yml

@@ -0,0 +1,64 @@
+
+# X11 default option to be able to test th result in the browser
+image: gitpod/workspace-full-vnc
+ports:
+  - port: 5900
+    onOpen: ignore
+  - port: 6080
+    onOpen: open-preview
+
+# build tasks, run in order but waiting on sync-points
+# last one is seen first
+tasks
+:
+
+- name: setup coding environment on Ubuntu 20.04
+  init: |
+    sudo add-apt-repository ppa:beineri/opt-qt-5.15.4-focal -y
+    sudo add-apt-repository ppa:kubuntu-ppa/backports -y
+    sudo apt-get update
+    sudo apt-get -y upgrade
+    sudo apt-get install -y qt515base qt515svg qt515x11extras cmake libdwarf-dev mesa-common-dev \
+        libboost-iostreams-dev libboost-program-options-dev libboost-system-dev libboost-filesystem-dev \
+        build-essential curl git wget autotools-dev autoconf libtool liblzma-dev libz-dev gettext cmake \
+        libzstd-dev ninja-build libdw-dev libelf-dev extra-cmake-modules \
+        libkf5archive-dev libkf5threadweaver-dev libkf5i18n-dev libkf5configwidgets-dev \
+        libkf5coreaddons-dev libkf5itemviews-dev libkf5itemmodels-dev libkf5kio-dev libkf5parts-dev \
+        libkf5solid-dev libkf5windowsystem-dev libkf5notifications-dev libkf5iconthemes-dev \
+        libqt5svg5-dev libqcustomplot-dev \
+        libqt5x11extras5-dev   # this one is optional for Hotspot, but required for KDDockWidgets
+    gp sync-done system-prepare
+
+- name: manual addition of KDDockWidgets
+  env:
+    KDDW_VER: 1.6.0
+  init: |
+    cd /workspace
+    wget https://github.com/KDAB/KDDockWidgets/releases/download/v$KDDW_VER/kddockwidgets-$KDDW_VER.tar.gz
+    tar -xf kddockwidgets-$KDDW_VER.tar.gz
+    cd kddockwidgets-$KDDW_VER
+    gp sync-await system-prepare
+    export PATH="/opt/bin:/opt/qt515/bin:${PATH}"
+    export PKG_CONFIG_PATH="/opt/qt515/lib/pkgconfig:${PKG_CONFIG_PATH}"
+    export LD_LIBRARY_PATH="/opt/qt515/lib:/opt/qt515/lib/x86_64-linux-gnu"
+    cmake -DCMAKE_INSTALL_PREFIX=/opt/KDAB .
+    make -j $(nproc) && sudo make install
+    gp sync-done kddw-installed
+
+- name: actual building and running of hotspot
+  init: |
+    mkdir -p build
+    cd build
+    gp sync-await kddw-installed
+    export PATH="/opt/bin:/opt/qt515/bin:${PATH}"
+    export PKG_CONFIG_PATH="/opt/qt515/lib/pkgconfig:${PKG_CONFIG_PATH}"
+    export LD_LIBRARY_PATH="/opt/qt515/lib:/opt/qt515/lib/x86_64-linux-gnu"
+    cmake -DCMAKE_INSTALL_PREFIX=/opt/KDAB ..
+    make -j $(nproc)
+  command: /workspace/hotspot/build/bin/hotspot /workspace/hotspot/tests/integrationtests/custom_cost_aggregation_testfiles/custom_cost_aggregation.perfparser
+
+# some config to ease working in the browser
+vscode:
+  extensions:
+    - llvm-vs-code-extensions.vscode-clangd
+    - twxs.cmake