Qt6 compatibility (#3779)

Author: lgritz

.github/workflows/ci.yml

@@ -233,14 +233,14 @@ jobs:
         include:
           - desc: latest releases gcc11 C++17 avx2 exr3.1 ocio2.2
             nametag: linux-latest-releases
-            os: ubuntu-20.04
+            os: ubuntu-22.04
             cc_compiler: gcc-11
             cxx_compiler: g++-11
             cxx_std: 17
             fmt_ver: 9.1.0
             openexr_ver: v3.1.5
             pybind11_ver: v2.10.0
-            python_ver: 3.8
+            python_ver: "3.10"
             simd: avx2,f16c
             setenvs: export LIBRAW_VERSION=0.20.2
                             LIBTIFF_VERSION=v4.5.0
@@ -391,6 +391,7 @@ jobs:
             cxx_std: 17
             python_ver: "3.9"
             aclang: 13
+            setenvs: export QT_VERSION=@5
           - desc: MacOS-12
             os: macos-12
             nametag: macos12-py310

src/build-scripts/gh-installdeps.bash

@@ -73,8 +73,12 @@ else
         libopencolorio-dev \
         libopencv-dev \
         libhdf5-dev
-    time sudo apt-get -q install -y \
-        qt5-default || /bin/true
+    if [[ "${QT_VERSION:-5}" == "5" ]] ; then
+        time sudo apt-get -q install -y \
+            qt5-default || /bin/true
+    elif [[ "${QT_VERSION}" == "6" ]] ; then
+        time sudo apt-get -q install -y qt6-base-dev || /bin/true
+    fi
     if [[ "${EXTRA_DEP_PACKAGES}" != "" ]] ; then
         time sudo apt-get -q install -y ${EXTRA_DEP_PACKAGES}
     fi

src/build-scripts/install_homebrew_deps.bash

@@ -39,7 +39,7 @@ brew install --display-times -q ffmpeg libheif ptex || true
 brew install --display-times -q tbb || true
 brew install --display-times -q openvdb || true
 brew install --display-times -q opencv || true
-brew install --display-times -q qt@5
+brew install --display-times -q qt${QT_VERSION}
 
 echo ""
 echo "After brew installs:"

src/cmake/externalpackages.cmake

@@ -255,21 +255,22 @@ checked_find_package (R3DSDK)  # RED camera
 set (NUKE_VERSION "7.0" CACHE STRING "Nuke version to target")
 checked_find_package (Nuke)
 
-checked_find_package (OpenGL)   # used for iv
 
 # Qt -- used for iv
-set (qt5_modules Core Gui Widgets)
-if (OPENGL_FOUND)
-    list (APPEND qt5_modules OpenGL)
-endif ()
 option (USE_QT "Use Qt if found" ON)
-checked_find_package (Qt5 COMPONENTS ${qt5_modules})
-if (USE_QT AND NOT Qt5_FOUND AND APPLE)
-    message (STATUS "  If you think you installed qt5 with Homebrew and it still doesn't work,")
-    message (STATUS "  try:   export PATH=/usr/local/opt/qt5/bin:$PATH")
+if (USE_QT)
+    checked_find_package (OpenGL)   # used for iv
+endif ()
+if (USE_QT AND OPENGL_FOUND)
+    checked_find_package (Qt6 COMPONENTS Core Gui Widgets OpenGLWidgets)
+    if (NOT Qt6_FOUND)
+        checked_find_package (Qt5 COMPONENTS Core Gui Widgets OpenGL)
+    endif ()
+    if (NOT Qt5_FOUND AND NOT Qt6_FOUND AND APPLE)
+        message (STATUS "  If you think you installed qt with Homebrew and it still doesn't work,")
+        message (STATUS "  try:   export PATH=/usr/local/opt/qt/bin:$PATH")
+    endif ()
 endif ()
-
-
 
 
 ###########################################################################

src/iv/CMakeLists.txt

@@ -3,23 +3,36 @@
 # https://github.com/OpenImageIO/oiio
 
 set (CMAKE_AUTOMOC ON)
-if (Qt5_POSITION_INDEPENDENT_CODE)
+if (Qt5_POSITION_INDEPENDENT_CODE OR Qt6_POSITION_INDEPENDENT_CODE)
     set (CMAKE_POSITION_INDEPENDENT_CODE ON)
 endif()
 
 check_is_enabled (iv iv_enabled)
-if (iv_enabled AND Qt5_FOUND AND OPENGL_FOUND)
+if (iv_enabled AND (Qt5_FOUND OR Qt6_FOUND) AND OPENGL_FOUND)
     fancy_add_executable (
         SYSTEM_INCLUDE_DIRS
             ${OPENGL_INCLUDE_DIR}
         LINK_LIBRARIES
             OpenImageIO
-            Qt5::Core Qt5::Gui Qt5::Widgets Qt5::OpenGL
+            $<TARGET_NAME_IF_EXISTS:Qt5::Core>
+            $<TARGET_NAME_IF_EXISTS:Qt5::Gui>
+            $<TARGET_NAME_IF_EXISTS:Qt5::Widgets>
+            $<TARGET_NAME_IF_EXISTS:Qt5::OpenGL>
+            $<TARGET_NAME_IF_EXISTS:Qt6::Core>
+            $<TARGET_NAME_IF_EXISTS:Qt6::Gui>
+            $<TARGET_NAME_IF_EXISTS:Qt6::Widgets>
+            $<TARGET_NAME_IF_EXISTS:Qt6::OpenGLWidgets>
             ${OPENGL_LIBRARIES}
         )
     if (iv_enabled AND FORCE_OPENGL_1)
         target_compile_definitions(iv PRIVATE FORCE_OPENGL_1)
     endif()
+    if (Qt5_FOUND)
+        target_compile_definitions(iv PRIVATE OIIO_QT_MAJOR=5)
+    endif ()
+    if (Qt6_FOUND)
+        target_compile_definitions(iv PRIVATE OIIO_QT_MAJOR=6)
+    endif ()
 else ()
     message (STATUS "\n\n   WARNING: Qt or OpenGL not found -- 'iv' will not be built!\n")
 endif ()

src/iv/imageviewer.cpp

@@ -9,12 +9,15 @@
 #endif
 #include <vector>
 
+#ifndef OIIO_QT_MAJOR
+#    error "Build problem? OIIO_QT_MAJOR not defined."
+#endif
+
 #include "imageviewer.h"
 #include "ivgl.h"
 
 #include <QApplication>
 #include <QComboBox>
-#include <QDesktopWidget>
 #include <QFileDialog>
 #include <QKeyEvent>
 #include <QLabel>
@@ -28,6 +31,10 @@
 #include <QStatusBar>
 #include <QTimer>
 
+#if OIIO_QT_MAJOR < 6
+#    include <QDesktopWidget>
+#endif
+
 #include <OpenImageIO/dassert.h>
 #include <OpenImageIO/filesystem.h>
 #include <OpenImageIO/imagecache.h>
@@ -1951,9 +1958,14 @@ ImageViewer::fitWindowToImage(bool zoomok, bool minsize)
     }
 
     if (!m_fullscreen) {
-        QDesktopWidget* desktop = QApplication::desktop();
-        QRect availgeom         = desktop->availableGeometry(this);
-        int availwidth          = availgeom.width() - extraw - 20;
+#if OIIO_QT_MAJOR >= 6
+        auto desktop    = this->screen();
+        QRect availgeom = desktop->availableGeometry();
+#else
+        auto desktop    = QApplication::desktop();
+        QRect availgeom = desktop->availableGeometry(this);
+#endif
+        int availwidth  = availgeom.width() - extraw - 20;
         int availheight = availgeom.height() - extrah - menuBar()->height()
                           - 20;
 #if 0

src/iv/imageviewer.h

@@ -23,9 +23,14 @@
 #include <QAction>
 #include <QCheckBox>
 #include <QDialog>
-#include <QGLWidget>
 #include <QMainWindow>
 
+#if OIIO_QT_MAJOR < 6
+#    include <QGLWidget>
+#else
+#    include <QOpenGLWidget>
+#endif
+
 #ifndef QT_NO_PRINTER
 // #include <QPrinter>
 #endif

src/iv/ivgl.cpp

@@ -11,6 +11,10 @@
 #include <QLabel>
 #include <QMouseEvent>
 #include <QProgressBar>
+#if OIIO_QT_MAJOR >= 6
+#    include <QPainter>
+#    include <QPen>
+#endif
 
 #include "ivutils.h"
 #include <OpenImageIO/strutil.h>