cmake: Require Qt 6 to build GUI

.github/ISSUE_TEMPLATE/good_first_issue.yml

@@ -28,7 +28,7 @@ body:
     id: useful-skills
     attributes:
       label: Useful Skills
-      description: For example, “`std::thread`”, “Qt5 GUI and async GUI design” or “basic understanding of Bitcoin mining and the Bitcoin Core RPC interface”.
+      description: For example, “`std::thread`”, “Qt6 GUI and async GUI design” or “basic understanding of Bitcoin mining and the Bitcoin Core RPC interface”.
       value: |
         * Compiling Bitcoin Core from source
         * Running the C++ unit tests and the Python functional tests

CMakeLists.txt

@@ -174,7 +174,7 @@ if(BUILD_GUI)
   if(BUILD_GUI_TESTS)
     list(APPEND qt_components Test)
   endif()
-  find_package(Qt 5.11.3 MODULE REQUIRED
+  find_package(Qt 6.2 MODULE REQUIRED
     COMPONENTS ${qt_components}
   )
   unset(qt_components)

cmake/module/FindQt.cmake

@@ -27,19 +27,6 @@ if(CMAKE_HOST_APPLE)
   endif()
 endif()
 
-# Save CMAKE_FIND_ROOT_PATH_MODE_LIBRARY state.
-unset(_qt_find_root_path_mode_library_saved)
-if(DEFINED CMAKE_FIND_ROOT_PATH_MODE_LIBRARY)
-  set(_qt_find_root_path_mode_library_saved ${CMAKE_FIND_ROOT_PATH_MODE_LIBRARY})
-endif()
-
-# The Qt config files internally use find_library() calls for all
-# dependencies to ensure their availability. In turn, the find_library()
-# inspects the well-known locations on the file system; therefore, it must
-# be able to find platform-specific system libraries, for example:
-# /usr/x86_64-w64-mingw32/lib/libm.a or /usr/arm-linux-gnueabihf/lib/libm.a.
-set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY BOTH)
-
 find_package(Qt${Qt_FIND_VERSION_MAJOR} ${Qt_FIND_VERSION}
   COMPONENTS ${Qt_FIND_COMPONENTS}
   HINTS ${_qt_homebrew_prefix}
@@ -47,14 +34,6 @@ find_package(Qt${Qt_FIND_VERSION_MAJOR} ${Qt_FIND_VERSION}
 )
 unset(_qt_homebrew_prefix)
 
-# Restore CMAKE_FIND_ROOT_PATH_MODE_LIBRARY state.
-if(DEFINED _qt_find_root_path_mode_library_saved)
-  set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ${_qt_find_root_path_mode_library_saved})
-  unset(_qt_find_root_path_mode_library_saved)
-else()
-  unset(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY)
-endif()
-
 include(FindPackageHandleStandardArgs)
 find_package_handle_standard_args(Qt
   REQUIRED_VARS Qt${Qt_FIND_VERSION_MAJOR}_DIR

doc/build-freebsd.md

@@ -62,13 +62,13 @@ sh/bash: export BDB_PREFIX=[path displayed above]
 ```
 
 #### GUI Dependencies
-###### Qt5
+###### Qt6
 
 Bitcoin Core includes a GUI built with the cross-platform Qt Framework. To compile the GUI, we need to install
 the necessary parts of Qt, the libqrencode and pass `-DBUILD_GUI=ON`. Skip if you don't intend to use the GUI.
 
 ```bash
-pkg install qt5-buildtools qt5-core qt5-gui qt5-linguisttools qt5-testlib qt5-widgets
+pkg install qt6-buildtools qt6-core qt6-gui qt6-linguisttools qt6-testlib qt6-widgets
 ```
 
 ###### libqrencode

doc/build-netbsd.md

@@ -64,13 +64,13 @@ pkgin install db4
 ```
 
 #### GUI Dependencies
-###### Qt5
+###### Qt6
 
 Bitcoin Core includes a GUI built with the cross-platform Qt Framework. To compile the GUI, we need to install
 the necessary parts of Qt, the libqrencode and pass `-DBUILD_GUI=ON`. Skip if you don't intend to use the GUI.
 
 ```bash
-pkgin install qt5-qtbase qt5-qttools
+pkgin install qt6-qtbase qt6-qttools
 ```
 
 ###### libqrencode

doc/build-openbsd.md

@@ -56,13 +56,13 @@ export BDB_PREFIX="[path displayed above]"
 ```
 
 #### GUI Dependencies
-###### Qt5
+###### Qt6
 
 Bitcoin Core includes a GUI built with the cross-platform Qt Framework. To compile the GUI, we need to install
 the necessary parts of Qt, the libqrencode and pass `-DBUILD_GUI=ON`. Skip if you don't intend to use the GUI.
 
 ```bash
-pkg_add qtbase qttools
+pkg_add qt6-qtbase qt6-qttools
 ```
 
 ###### libqrencode
@@ -100,7 +100,7 @@ pkg_add python py3-zmq  # Select the newest version of the python package if nec
 There are many ways to configure Bitcoin Core, here are a few common examples:
 
 ##### Descriptor Wallet and GUI:
-This enables descriptor wallet support and the GUI, assuming SQLite and Qt 5 are installed.
+This enables descriptor wallet support and the GUI, assuming SQLite and Qt 6 are installed.
 
 ```bash
 cmake -B build -DBUILD_GUI=ON

doc/build-osx.md

@@ -92,11 +92,9 @@ Bitcoin Core includes a GUI built with the cross-platform Qt Framework. To compi
 Qt, libqrencode and pass `-DBUILD_GUI=ON`. Skip if you don't intend to use the GUI.
 
 ``` bash
-brew install qt@5
+brew install qt@6
 ```
 
-Note: Building may fail if Qt 6 is installed (`qt` or `qt@6`)
-
 Note: Building with Qt binaries downloaded from the Qt website is not officially supported.
 See the notes in [#7714](https://github.com/bitcoin/bitcoin/issues/7714).
 

doc/build-unix.md

@@ -73,11 +73,13 @@ GUI dependencies:
 Bitcoin Core includes a GUI built with the cross-platform Qt Framework. To compile the GUI, we need to install
 the necessary parts of Qt, the libqrencode and pass `-DBUILD_GUI=ON`. Skip if you don't intend to use the GUI.
 
-    sudo apt-get install qtbase5-dev qttools5-dev qttools5-dev-tools
+    sudo apt-get install qt6-base-dev qt6-tools-dev qt6-l10n-tools
+
+For Qt 6.5 and later, the `libxcb-cursor0` package must be installed at runtime.
 
 Additionally, to support Wayland protocol for modern desktop environments:
 
-    sudo apt install qtwayland5
+    sudo apt install qt6-wayland
 
 The GUI will be able to encode addresses in QR codes unless this feature is explicitly disabled. To install libqrencode, run:
 
@@ -121,11 +123,13 @@ GUI dependencies:
 Bitcoin Core includes a GUI built with the cross-platform Qt Framework. To compile the GUI, we need to install
 the necessary parts of Qt, the libqrencode and pass `-DBUILD_GUI=ON`. Skip if you don't intend to use the GUI.
 
-    sudo dnf install qt5-qttools-devel qt5-qtbase-devel
+    sudo dnf install qt6-qtbase-devel qt6-qttools-devel
+
+For Qt 6.5 and later, the `xcb-util-cursor` package must be installed at runtime.
 
 Additionally, to support Wayland protocol for modern desktop environments:
 
-    sudo dnf install qt5-qtwayland
+    sudo dnf install qt6-qtwayland
 
 The GUI will be able to encode addresses in QR codes unless this feature is explicitly disabled. To install libqrencode, run:
 

src/qt/CMakeLists.txt

@@ -11,21 +11,35 @@ if(CMAKE_SYSTEM_NAME STREQUAL "Darwin")
   string(APPEND CMAKE_OBJCXX_COMPILE_OBJECT " ${APPEND_CPPFLAGS} ${APPEND_CXXFLAGS}")
 endif()
 
-get_target_property(qt_lib_type Qt5::Core TYPE)
+get_target_property(qt_lib_type Qt6::Core TYPE)
 
 function(import_plugins target)
   if(qt_lib_type STREQUAL "STATIC_LIBRARY")
-    set(plugins Qt5::QMinimalIntegrationPlugin)
+    set(plugins Qt6::QMinimalIntegrationPlugin)
     if(CMAKE_SYSTEM_NAME STREQUAL "Linux")
-      list(APPEND plugins Qt5::QXcbIntegrationPlugin)
+      list(APPEND plugins Qt6::QXcbIntegrationPlugin)
     elseif(WIN32)
-      list(APPEND plugins Qt5::QWindowsIntegrationPlugin Qt5::QWindowsVistaStylePlugin)
+      list(APPEND plugins Qt6::QWindowsIntegrationPlugin Qt6::QWindowsVistaStylePlugin)
     elseif(APPLE)
-      list(APPEND plugins Qt5::QCocoaIntegrationPlugin Qt5::QMacStylePlugin)
+      list(APPEND plugins Qt6::QCocoaIntegrationPlugin Qt6::QMacStylePlugin)
     endif()
-    qt5_import_plugins(${target}
+    qt6_import_plugins(${target}
       INCLUDE ${plugins}
-      EXCLUDE_BY_TYPE imageformats iconengines
+      EXCLUDE_BY_TYPE
+        accessiblebridge
+        platforms
+        platforms_darwin
+        xcbglintegrations
+        platformthemes
+        platforminputcontexts
+        generic
+        iconengines
+        imageformats
+        egldeviceintegrations
+        styles
+        networkaccess
+        networkinformation
+        tls
     )
   endif()
 endfunction()
@@ -45,7 +59,7 @@ set(CMAKE_AUTOUIC_SEARCH_PATHS forms)
 # to https://github.com/bitcoin-core/bitcoin-maintainer-tools/blob/main/update-translations.py
 file(GLOB ts_files RELATIVE ${CMAKE_CURRENT_SOURCE_DIR} locale/*.ts)
 set_source_files_properties(${ts_files} PROPERTIES OUTPUT_LOCATION ${CMAKE_CURRENT_BINARY_DIR}/locale)
-qt5_add_translation(qm_files ${ts_files})
+qt6_add_translation(qm_files ${ts_files})
 
 configure_file(bitcoin_locale.qrc bitcoin_locale.qrc USE_SOURCE_PERMISSIONS COPYONLY)
 
@@ -128,7 +142,7 @@ set_property(SOURCE macnotificationhandler.mm
 )
 target_link_libraries(bitcoinqt
   PUBLIC
-    Qt5::Widgets
+    Qt6::Widgets
   PRIVATE
     core_interface
     bitcoin_cli
@@ -206,19 +220,33 @@ if(ENABLE_WALLET)
   target_link_libraries(bitcoinqt
     PRIVATE
       bitcoin_wallet
-      Qt5::Network
+      Qt6::Network
   )
 endif()
 
 if(WITH_DBUS)
-  target_link_libraries(bitcoinqt PRIVATE Qt5::DBus)
+  target_link_libraries(bitcoinqt PRIVATE Qt6::DBus)
 endif()
 
 if(qt_lib_type STREQUAL "STATIC_LIBRARY")
   # We want to define static plugins to link ourselves, thus preventing
   # automatic linking against a "sane" set of default static plugins.
-  qt5_import_plugins(bitcoinqt
+  qt6_import_plugins(bitcoinqt
-      EXCLUDE_BY_TYPE bearer iconengines imageformats platforms styles
+    EXCLUDE_BY_TYPE
+      accessiblebridge
+      platforms
+      platforms_darwin
+      xcbglintegrations
+      platformthemes
+      platforminputcontexts
+      generic
+      iconengines
+      imageformats
+      egldeviceintegrations
+      styles
+      networkaccess
+      networkinformation
+      tls
   )
 endif()
 
@@ -321,8 +349,8 @@ else()
   file(GLOB ui_files ${CMAKE_CURRENT_SOURCE_DIR}/forms/*.ui)
   add_custom_target(translate
     COMMAND ${CMAKE_COMMAND} -E env XGETTEXT=${XGETTEXT_EXECUTABLE} COPYRIGHT_HOLDERS=${COPYRIGHT_HOLDERS} ${Python3_EXECUTABLE} ${PROJECT_SOURCE_DIR}/share/qt/extract_strings_qt.py ${translatable_sources}
-    COMMAND Qt5::lupdate -no-obsolete -I ${PROJECT_SOURCE_DIR}/src -locations relative ${CMAKE_CURRENT_SOURCE_DIR}/bitcoinstrings.cpp ${ui_files} ${qt_translatable_sources} -ts ${CMAKE_CURRENT_SOURCE_DIR}/locale/bitcoin_en.ts
+    COMMAND Qt6::lupdate -no-obsolete -I ${PROJECT_SOURCE_DIR}/src -locations relative ${CMAKE_CURRENT_SOURCE_DIR}/bitcoinstrings.cpp ${ui_files} ${qt_translatable_sources} -ts ${CMAKE_CURRENT_SOURCE_DIR}/locale/bitcoin_en.ts
-    COMMAND Qt5::lconvert -drop-translations -o ${CMAKE_CURRENT_SOURCE_DIR}/locale/bitcoin_en.xlf -i ${CMAKE_CURRENT_SOURCE_DIR}/locale/bitcoin_en.ts
+    COMMAND Qt6::lconvert -drop-translations -o ${CMAKE_CURRENT_SOURCE_DIR}/locale/bitcoin_en.xlf -i ${CMAKE_CURRENT_SOURCE_DIR}/locale/bitcoin_en.ts
     COMMAND ${SED_EXECUTABLE} -i.old -e "s|source-language=\"en\" target-language=\"en\"|source-language=\"en\"|" -e "/<target xml:space=\"preserve\"><\\/target>/d" ${CMAKE_CURRENT_SOURCE_DIR}/locale/bitcoin_en.xlf
     COMMAND ${CMAKE_COMMAND} -E rm ${CMAKE_CURRENT_SOURCE_DIR}/locale/bitcoin_en.xlf.old
     WORKING_DIRECTORY ${PROJECT_SOURCE_DIR}/src

src/qt/sendcoinsdialog.cpp

@@ -88,7 +88,11 @@ SendCoinsDialog::SendCoinsDialog(const PlatformStyle *_platformStyle, QWidget *p
 
     // Coin Control
     connect(ui->pushButtonCoinControl, &QPushButton::clicked, this, &SendCoinsDialog::coinControlButtonClicked);
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 7, 0))
+    connect(ui->checkBoxCoinControlChange, &QCheckBox::checkStateChanged, this, &SendCoinsDialog::coinControlChangeChecked);
+#else
     connect(ui->checkBoxCoinControlChange, &QCheckBox::stateChanged, this, &SendCoinsDialog::coinControlChangeChecked);
+#endif
     connect(ui->lineEditCoinControlChange, &QValidatedLineEdit::textEdited, this, &SendCoinsDialog::coinControlChangeEdited);
 
     // Coin Control: clipboard actions
@@ -183,8 +187,13 @@ void SendCoinsDialog::setModel(WalletModel *_model)
 #endif
 
         connect(ui->customFee, &BitcoinAmountField::valueChanged, this, &SendCoinsDialog::coinControlUpdateLabels);
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 7, 0))
+        connect(ui->optInRBF, &QCheckBox::checkStateChanged, this, &SendCoinsDialog::updateSmartFeeLabel);
+        connect(ui->optInRBF, &QCheckBox::checkStateChanged, this, &SendCoinsDialog::coinControlUpdateLabels);
+#else
         connect(ui->optInRBF, &QCheckBox::stateChanged, this, &SendCoinsDialog::updateSmartFeeLabel);
         connect(ui->optInRBF, &QCheckBox::stateChanged, this, &SendCoinsDialog::coinControlUpdateLabels);
+#endif
         CAmount requiredFee = model->wallet().getRequiredFee(1000);
         ui->customFee->SetMinValue(requiredFee);
         if (ui->customFee->value() < requiredFee) {
@@ -944,7 +953,11 @@ void SendCoinsDialog::coinControlButtonClicked()
 }
 
 // Coin Control: checkbox custom change address
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 7, 0))
+void SendCoinsDialog::coinControlChangeChecked(Qt::CheckState state)
+#else
 void SendCoinsDialog::coinControlChangeChecked(int state)
+#endif
 {
     if (state == Qt::Unchecked)
     {

src/qt/sendcoinsdialog.h

@@ -103,7 +103,11 @@ private Q_SLOTS:
     void refreshBalance();
     void coinControlFeatureChanged(bool);
     void coinControlButtonClicked();
+#if (QT_VERSION >= QT_VERSION_CHECK(6, 7, 0))
+    void coinControlChangeChecked(Qt::CheckState);
+#else
     void coinControlChangeChecked(int);
+#endif
     void coinControlChangeEdited(const QString &);
     void coinControlUpdateLabels();
     void coinControlClipboardQuantity();

src/qt/test/CMakeLists.txt

@@ -20,7 +20,7 @@ target_link_libraries(test_bitcoin-qt
   test_util
   bitcoin_node
   Boost::headers
-  Qt5::Test
+  Qt6::Test
 )
 
 import_plugins(test_bitcoin-qt)