chore: make use of CMake project version

CMakeLists.txt

@@ -4,7 +4,7 @@
 
 cmake_minimum_required (VERSION 3.9.5)
 
-project (pineapple-pictures)
+project(pineapple-pictures VERSION 0.8.1) # don't forget to update NEWS file and AppStream metadata.
 
 include (GNUInstallDirs)
 include (FeatureSummary)
@@ -179,6 +179,7 @@ macro (ppic_set_version_via_describe _describe_long)
 endmacro ()
 
 # Version setup
+target_compile_definitions(${EXE_NAME} PRIVATE PPIC_VERSION_STRING="${CMAKE_PROJECT_VERSION}")
 if (EXISTS "${CMAKE_SOURCE_DIR}/.git")
     find_package(Git)
     set_package_properties(Git PROPERTIES TYPE OPTIONAL PURPOSE "Determine exact build version.")

app/aboutdialog.cpp

@@ -50,9 +50,13 @@ AboutDialog::AboutDialog(QWidget *parent)
     const QStringList aboutStr {
         QStringLiteral("<center><img width='128' height='128' src=':/icons/app-icon.svg'/><br/>"),
         qApp->applicationDisplayName(),
+        (QStringLiteral("<br/>") + tr("Version: %1").arg(
 #ifdef GIT_DESCRIBE_VERSION_STRING
-        (QStringLiteral("<br/>") + tr("Version: %1").arg(GIT_DESCRIBE_VERSION_STRING)),
+            GIT_DESCRIBE_VERSION_STRING
+#else
+            qApp->applicationVersion()
 #endif // GIT_DESCRIBE_VERSION_STRING
+        )),
         QStringLiteral("<hr/>"),
         tr("Copyright (c) %1 %2", "%1 is year, %2 is the name of copyright holder(s)")
             .arg(QStringLiteral("2024"), QStringLiteral("<a href='https://github.com/BLumia'>@BLumia</a>")),

app/main.cpp

@@ -39,6 +39,7 @@ int main(int argc, char *argv[])
     }
     a.setApplicationName("Pineapple Pictures");
     a.setApplicationDisplayName(QCoreApplication::translate("main", "Pineapple Pictures"));
+    a.setApplicationVersion(PPIC_VERSION_STRING);
 
     // commandline options
     QCommandLineOption supportedImageFormats(QStringLiteral("supported-image-formats"), QCoreApplication::translate("main", "List supported image format suffixes, and quit program."));