CPack/NSIS: Add option for setting branding text

See https://nsis.sourceforge.io/Reference/BrandingText
for more information.

Fixes: #21479

Help/cpack_gen/nsis.rst

@@ -180,3 +180,16 @@ on Windows Nullsoft Scriptable Install System.
  .. versionadded:: 3.18
 
  If set, declares that the installer is DPI-aware.
+
+.. variable:: CPACK_NSIS_BRANDING_TEXT
+
+ .. versionadded:: 3.20
+
+ If set, updates the text at the bottom of the install window.
+ To set the string to blank, use a space (" ").
+
+.. variable:: CPACK_NSIS_BRANDING_TEXT_TRIM_POSITION
+
+ .. versionadded:: 3.20
+
+ If set, trim down the size of the control to the size of the branding text string.

Help/release/dev/cpack-nsis-branding-text.rst

@@ -0,0 +1,7 @@
+cpack-nsis-branding-text
+------------------------
+
+* The :cpack_gen:`CPack NSIS Generator` gained new variables
+  :variable:`CPACK_NSIS_BRANDING_TEXT` and
+  :variable:`CPACK_NSIS_BRANDING_TEXT_TRIM_POSITION` to change the
+  text at the bottom of the install window and change its trim position

Modules/Internal/CPack/NSIS.template.in

@@ -42,6 +42,7 @@
 
 @CPACK_NSIS_DEFINES@
 @CPACK_NSIS_MANIFEST_DPI_AWARE_CODE@
+@CPACK_NSIS_BRANDING_TEXT_CODE@
 
   !include Sections.nsh
 

Source/CPack/cmCPackNSISGenerator.cxx

@@ -209,6 +209,25 @@ int cmCPackNSISGenerator::PackageFiles()
                             "ManifestDPIAware true");
   }
 
+  if (this->IsSet("CPACK_NSIS_BRANDING_TEXT")) {
+    // Default position to LEFT
+    std::string brandingTextPosition = "LEFT";
+    if (this->IsSet("CPACK_NSIS_BRANDING_TEXT_TRIM_POSITION")) {
+      std::string wantedPosition =
+        this->GetOption("CPACK_NSIS_BRANDING_TEXT_TRIM_POSITION");
+      const std::set<std::string> possiblePositions{ "CENTER", "LEFT",
+                                                     "RIGHT" };
+      if (possiblePositions.find(wantedPosition) != possiblePositions.end()) {
+        brandingTextPosition = wantedPosition;
+      }
+    }
+    std::string brandingTextCode =
+      cmStrCat("BrandingText /TRIM", brandingTextPosition, " \"",
+               this->GetOption("CPACK_NSIS_BRANDING_TEXT"), "\"\n");
+    this->SetOptionIfNotSet("CPACK_NSIS_BRANDING_TEXT_CODE",
+                            brandingTextCode.c_str());
+  }
+
   // Setup all of the component sections
   if (this->Components.empty()) {
     this->SetOptionIfNotSet("CPACK_NSIS_INSTALLATION_TYPES", "");

Tests/CPackNSISGenerator/CMakeLists.txt

@@ -17,5 +17,7 @@ set(CPACK_NSIS_MUI_UNIICON "${PROJECT_SOURCE_DIR}\\\\uninstall.ico")
 set(CPACK_GENERATOR "NSIS")
 set(CPACK_NSIS_ENABLE_UNINSTALL_BEFORE_INSTALL ON)
 set(CPACK_NSIS_MANIFEST_DPI_AWARE ON)
+set(CPACK_NSIS_BRANDING_TEXT "CMake branding text")
+set(CPACK_NSIS_BRANDING_TEXT_TRIM_POSITION "RIGHT")
 
 include(CPack)

Tests/CPackNSISGenerator/RunCPackVerifyResult.cmake

@@ -52,3 +52,11 @@ if("${output_index}" EQUAL "-1")
 else()
   message(STATUS "Found DPI-aware")
 endif()
+
+file(STRINGS "${project_file}" line REGEX "^BrandingText /TRIMRIGHT \"CMake branding text\"")
+string(FIND "${line}" "TRIMRIGHT" output_index)
+if("${output_index}" EQUAL "-1")
+  message(FATAL_ERROR "BrandingText not found in the project")
+else()
+  message(STATUS "Found BrandingText")
+endif()