Fixes #15, adjust macOS paths to Qt

[statik]

Thank you for creating this plugin 👍

When I tried to use it today after installing from media-controls-0.3.0-macos.pkg.zip, I noticed this load failure in my OBS logs:

11:10:04.115: os_dlopen(/Library/Application Support/obs-studio/plugins/media-controls/bin/media-controls.so->/Library/Application Support/obs-studio/plugins/media-controls/bin/media-controls.so): dlopen(/Library/Application Support/obs-studio/plugins/media-controls/bin/media-controls.so, 257): Library not loaded: /tmp/obsdeps/lib/QtWidgets.framework/Versions/5/QtWidgets
11:10:04.115:   Referenced from: /Library/Application Support/obs-studio/plugins/media-controls/bin/media-controls.so
11:10:04.115:   Reason: image not found
11:10:04.115: 
11:10:04.115: Module '/Library/Application Support/obs-studio/plugins/media-controls/bin/media-controls.so' not loaded

I believe this is likely the underlying problem with #15. When I inspected the library paths with otool, I saw paths for the Qt dependencies were still pointing to the tmp location used during the build:

otool -l '/Library/Application Support/obs-studio/plugins/media-controls/bin/media-controls.so'| grep tmp
         name /tmp/obsdeps/lib/QtWidgets.framework/Versions/5/QtWidgets (offset 24)
         name /tmp/obsdeps/lib/QtGui.framework/Versions/5/QtGui (offset 24)
         name /tmp/obsdeps/lib/QtCore.framework/Versions/5/QtCore (offset 24)

I see that the CI build script is already invoking install_name_tool to fix up these paths after the build and before packaging, it seems the path just didn't match the dependency path used earlier in the build. I created this temporary script to test the change to the paths, and after running this script against my local install, the plugin loads correctly and works great!

#!/usr/bin/env bash

PLUGIN='/Library/Application Support/obs-studio/plugins/media-controls/bin/media-controls.so'
OLD_PATH_PREFIX='/tmp/obsdeps/lib'
NEW_PATH_PREFIX='@executable_path/../Frameworks'
QT_WIDGETS='QtWidgets.framework/Versions/5/QtWidgets'
QT_GUI='QtGui.framework/Versions/5/QtGui'
QT_CORE='QtCore.framework/Versions/5/QtCore'

if ! otool -l "${PLUGIN}" | grep -q "${OLD_PATH_PREFIX}"; then
  echo "Old paths not found, nothing to do."
  exit 0
fi

echo "Found $OLD_PATH_PREFIX entries inside $PLUGIN, patching"

install_name_tool \
  -change "${OLD_PATH_PREFIX}/${QT_WIDGETS}" "${NEW_PATH_PREFIX}/${QT_WIDGETS}" \
  -change "${OLD_PATH_PREFIX}/${QT_GUI}" "${NEW_PATH_PREFIX}/${QT_GUI}" \
  -change "${OLD_PATH_PREFIX}/${QT_CORE}" "${NEW_PATH_PREFIX}/${QT_CORE}" \
  "${PLUGIN}"

I hope this PR is helpful and will make it easy to cut a new release that works on macOS. Let me know if you would like me to test the new release or do anything else to help.

[statik]

I will rebase this to pull in the build fixes.

[exeldro]

I have no Mac to verify this PR. Can you verify the CI artifact works correct?

[statik]

@exeldro confirmed! Works great here.

1. sudo rm -rf '/Library/Application Support/obs-studio/plugins/media-controls/'
2. download and install artifact from this PR: https://github.com/exeldro/obs-media-controls/suites/1752591877/artifacts/33328242
3. verify otool shows expected path settings:

   otool -l '/Library/Application Support/obs-studio/plugins/media-controls/bin/media-controls.so'| grep Qt
        name @executable_path/../Frameworks/QtWidgets.framework/Versions/5/QtWidgets (offset 24)
        name @executable_path/../Frameworks/QtGui.framework/Versions/5/QtGui (offset 24)
        name @executable_path/../Frameworks/QtCore.framework/Versions/5/QtCore (offset 24)

4. Open OBS.app and confirm that media controls dock is working fine.

Thank you 🤝