Unifies CMake configuration for deepin V25/V20 dual-version support by automatically detecting Qt5/Qt6 and dynamically mapping DTK versions, eliminating hard-coded version references throughout the build system.

File Convention

| debian/control | V25 | Qt6

| debian/control.1 | V20 | Qt5

Why: control (no suffix) = latest version (V25), control.1 (with suffix) = previous version (V20).

When to Use

digraph when_to_use {
    "Qt/CMake project?" [shape=diamond];
    "V25/V20 dual support?" [shape=diamond];
    "Hard-coded Qt/DTK?" [shape=diamond];
    "Use this skill" [shape=box];
    "Wrong tool" [shape=box];

    "Qt/CMake project?" -> "V25/V20 dual support?" [label="yes"];
    "V25/V20 dual support?" -> "Hard-coded Qt/DTK?" [label="yes"];
    "Hard-coded Qt/DTK?" -> "Use this skill" [label="yes"];
}

Use when:

CMakeLists.txt has hard-coded Qt5:: or Qt6:: in target_link_libraries
CMakeLists.txt has hard-coded Dtk:: or Dtk6:: in find_package or linking
Projects need both V25 (Qt6) and V20 (Qt5) builds from same code
Need dynamic library linking based on detected Qt version
DTK dependencies need to map automatically to installed Qt version

Do NOT use when:

Projects without CMake build system
Projects without Qt dependencies
Single version support only (V25-only or V20-only)

Quick Reference

| Auto-detect Qt | find_package(QT NAMES Qt6 Qt5 REQUIRED COMPONENTS Core)

| Map DTK to Qt | if (QT_VERSION_MAJOR MATCHES 6) set(DTK_VERSION_MAJOR 6)

| Dynamic Qt find | find_package(Qt${QT_VERSION_MAJOR} COMPONENTS ${QT} REQUIRED)

| Dynamic DTK find | find_package(Dtk${DTK_VERSION_MAJOR}Widget REQUIRED)

| Dynamic Qt linking | Qt${QT_VERSION_MAJOR}::Core

| Dynamic DTK linking | Dtk${DTK_VERSION_MAJOR}::Core

| V25 build | cmake -B build -DQT_DIR=/usr/lib/x86_64-linux-gnu/cmake/Qt6

| V20 build | cmake -B build5 -DQT_DIR=/usr/lib/x86_64-linux-gnu/cmake/Qt5

Note: -DQT_DIR is optional for local build convenience. CMake auto-detects if not specified.

Implementation

Step 1: Add Qt Detection (CMakeLists.txt top)

# Auto-detect Qt version (tries Qt6 first, falls back to Qt5)
find_package(QT NAMES Qt6 Qt5 REQUIRED COMPONENTS Core)
message(STATUS "Found Qt version: ${QT_VERSION_MAJOR}")

# Map to DTK version (Qt6→DTK6, Qt5→DTK5)
if (QT_VERSION_MAJOR MATCHES 6)
    set(DTK_VERSION_MAJOR 6)
else()
    set(DTK_VERSION_MAJOR "")
endif()
message(STATUS "Build with DTK: ${DTK_VERSION_MAJOR}")

Step 2: Update All find_package Calls

Before (hard-coded):

find_package(Qt6 COMPONENTS Core Gui Widgets Network REQUIRED)
find_package(DtkWidget REQUIRED)

After (dynamic):

set(QT Core Gui Widgets Network DBus Sql Svg Test WebChannel WebSockets)
find_package(Qt${QT_VERSION_MAJOR} COMPONENTS ${QT} REQUIRED)

find_package(Dtk${DTK_VERSION_MAJOR}Widget REQUIRED)
find_package(Dtk${DTK_VERSION_MAJOR}Core REQUIRED)
find_package(Dtk${DTK_VERSION_MAJOR}Gui REQUIRED)

Step 3: Update All target_link_libraries

Before (hard-coded):

target_link_libraries(mylib
    Dtk::Core
    Dtk::Gui
    Qt6::Network
)

After (dynamic):

target_link_libraries(mylib
    Dtk${DTK_VERSION_MAJOR}::Core
    Dtk${DTK_VERSION_MAJOR}::Gui
    Qt${QT_VERSION_MAJOR}::Network
)

Replacement pattern:

Qt5:: → Qt${QT_VERSION_MAJOR}::
Qt6:: → Qt${QT_VERSION_MAJOR}::
Dtk:: → Dtk${DTK_VERSION_MAJOR}::
Dtk6:: → Dtk${DTK_VERSION_MAJOR}::

Step 4: Translation Generation (if needed)

Create cmake/translation-generate.cmake:

function(TRANSLATION_GENERATE QMS)
  find_package(Qt${QT_VERSION_MAJOR}LinguistTools QUIET)

  if (NOT Qt${QT_VERSION_MAJOR}_LRELEASE_EXECUTABLE)
    set(QT_LRELEASE "/lib/qt${QT_VERSION_MAJOR}/bin/lrelease")
    message(STATUS "NOT found lrelease, set QT_LRELEASE = ${QT_LRELEASE}")
  else()
    set(QT_LRELEASE "${Qt${QT_VERSION_MAJOR}_LRELEASE_EXECUTABLE}")
  endif()

  if(NOT ARGN)
    message(SEND_ERROR "Error: TRANSLATION_GENERATE() called without any .ts path")
    return()
  endif()

  file(GLOB TS_FILES "${ARGN}/*.ts")
  set(${QMS})
  foreach(TSFIL ${TS_FILES})
      get_filename_component(FIL_WE ${TSFIL} NAME_WE)
      set(QMFIL ${CMAKE_CURRENT_BINARY_DIR}/${FIL_WE}.qm)
      list(APPEND ${QMS} ${QMFIL})
      add_custom_command(
          OUTPUT ${QMFIL}
          COMMAND ${QT_LRELEASE} ${TSFIL} -qm ${QMFIL}
          DEPENDS ${TSFIL}
          COMMENT "Running ${QT_LRELEASE} on ${TSFIL}"
          VERBATIM
      )
  endforeach()

  set_source_files_properties(${${QMS}} PROPERTIES GENERATED TRUE)
  set(${QMS} ${${QMS}} PARENT_SCOPE)
endfunction()

Usage:

include(translation-generate)
TRANSLATION_GENERATE(QM_FILES ${CMAKE_SOURCE_DIR}/translations)
add_custom_target(${PROJECT_NAME}_qm_files DEPENDS ${QM_FILES})
add_dependencies(${PROJECT_NAME} ${PROJECT_NAME}_qm_files)
install(FILES ${QM_FILES} DESTINATION share/${PROJECT_NAME}/translations)

Step 5: Create Control Files

debian/control (V25/Qt6):

Build-Depends:
 cmake,
 pkg-config,
 qt6-base-dev,
 qt6-tools-dev,
 qt6-svg-dev,
 libdtk6widget-dev,
 libdtk6core-dev

debian/control.1 (V20/Qt5):

Build-Depends:
 cmake,
 pkg-config,
 qtbase5-dev,
 qttools5-dev,
 libqt5svg5-dev,
 libdtkwidget-dev,
 libdtkcore-dev

Dependency Mapping

| Base | qt6-base-dev | qtbase5-dev

| Tools | qt6-tools-dev | qttools5-dev

| SVG | qt6-svg-dev | libqt5svg5-dev

| DTK Widget | libdtk6widget-dev | libdtkwidget-dev

| DTK Core | libdtk6core-dev | libdtkcore-dev

Common Mistakes

| Hard-coded Qt5::Core / Qt6::Core | Forces specific Qt version | Use Qt${QT_VERSION_MAJOR}::Core

| Hard-coded Dtk::Core / Dtk6::Core | Forces specific DTK version | Use Dtk${DTK_VERSION_MAJOR}::Core

| Missing DTK_VERSION_MAJOR | DTK won't map to Qt version | Add variable mapping from Qt detection

| Only using control without control.1 | Won't support V20 | Create both control files

| Using OR dependencies in single control | Should use separate files | Split into control and control.1

| Only testing one Qt version | Both must work for dual support | Test V25 and V20 builds

| Not using find_package(QT NAMES Qt6 Qt5 ...) | Won't auto-detect both | Use correct find_package pattern

Red Flags - STOP and Check

Hard-coded Qt5/Qt6 in CMakeLists.txt → Must use QT_VERSION_MAJOR variable
Hard-coded DTK5/DTK6 in CMakeLists.txt → Must use DTK_VERSION_MAJOR variable
Missing DTK_VERSION_MAJOR variable → DTK won't map to Qt version
Using OR dependencies instead of separate control files → Should use control/control.1
Only testing one Qt version → Both versions must work
Qt detection not using find_package(QT NAMES Qt6 Qt5 ...) → Won't detect both versions

qt-compatibility-build

安装