Update CMake packaging and test with examples

[ntadej]

Improve how CMake package is exported. Now one does

find_package(QMapLibre COMPONENTS Core REQUIRED)

or

find_package(QMapLibre COMPONENTS Widgets REQUIRED)

Also update and cleanup the examples and test the installation using them.

@birkskyum, you can start using the widgets example for WASM. Separately I'll prepare a branch for the unstable WASM experiments.

[birkskyum]

@birkskyum, you can start using the widgets example for WASM.

doesn't that require this experimental singleton as well?

[ntadej]

Yes, but while you're waiting, you may as well already try to build with this setup. Just changing the branch later will be very fast (especially if you use ccache).

[birkskyum]

Hmm, so I clone maplibre-native-qt, and then from a sibling folder run something like this? How do I specify which executable to build?

qt-cmake ../maplibre-native-qt \   
-G Ninja \
-DCMAKE_BUILD_TYPE="RelWithDebInfo" \
-DMLN_WITH_QT=ON \
-DMLN_QT_STATIC=ON \
-DMLN_QT_WITH_INTERNAL_SQLITE=ON

ninja

ninja install

emrun --browser=chrome appname.html (do I build/link all executables, and select here?)

[ntadej]

See the README 😉

First you build MapLibre with

mkdir build && cd build
cmake ../maplibre-native-qt -GNinja \
  -DCMAKE_BUILD_TYPE="RelWithDebInfo" \
  -DCMAKE_C_COMPILER_LAUNCHER="ccache" \
  -DCMAKE_CXX_COMPILER_LAUNCHER="ccache" \
  -DCMAKE_INSTALL_PREFIX="../install" \
  -DMLN_QT_WITH_INTERNAL_SQLITE=ON
ninja
ninja install

Then you build the widgets example

mkdir build-example && cd build-example
qt-cmake ../maplibre-native-qt/examples/widgets -GNinja \
  -DCMAKE_C_COMPILER_LAUNCHER="ccache" \
  -DCMAKE_CXX_COMPILER_LAUNCHER="ccache" \
  -DCMAKE_PREFIX_PATH="<absolute-path-to-install>"
ninja