[contour] Adds CLI command contour image PATH to upload an image to…

… the terminal for displaying.

.github/workflows/build.yml

@@ -383,7 +383,7 @@ jobs:
         BUILD_DIR="build" \
           CMAKE_BUILD_TYPE="RelWithDebInfo" \
           CXX="g++-8" \
-          EXTRA_CMAKE_FLAGS="-DCONTOUR_BLUR_PLATFORM_KWIN=ON -DUSE_BOOST_FILESYSTEM=ON -DCONTOUR_INSTALL_TOOLS=ON" \
+          EXTRA_CMAKE_FLAGS="-DCONTOUR_BLUR_PLATFORM_KWIN=ON -DUSE_BOOST_FILESYSTEM=ON -DCONTOUR_INSTALL_TOOLS=ON -DCONTOUR_COMMAND_IMAGE=ON" \
           ./scripts/ci-prepare-contour.sh
     - name: "build"
       run: cmake --build build/ -- -j3

Changelog.md

@@ -1,7 +1,8 @@
 ### 0.3.1 (unreleased)
 
-* Fixes assertion on font resize when a (Sixel) image is currently being rendered (#642).
+- Fixes assertion on font resize when a (Sixel) image is currently being rendered (#642).
 - Fixes assertion on too quick shell terminations (#647).
+- Adds new command `contour image PATH_TO_IMAGE` to send an image file to the terminal for displaying for platforms that do provide libsixel.
 
 ### 0.3.0 (2022-04-18)
 

cmake/Findlibsixel.cmake

@@ -0,0 +1,79 @@
+# Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+# file Copyright.txt or https://cmake.org/licensing for details.
+
+#[=======================================================================[.rst:
+FindLibsixel
+------------
+
+Find Libsixel headers and library.
+
+Imported Targets
+^^^^^^^^^^^^^^^^
+
+``Libsixel::Libsixel``
+  The Libsixel library, if found.
+
+Result Variables
+^^^^^^^^^^^^^^^^
+
+This will define the following variables in your project:
+
+``Libsixel_FOUND``
+  true if (the requested version of) Fontconfig is available.
+``Libsixel_VERSION``
+  the version of Fontconfig.
+``Libsixel_LIBRARIES``
+  the libraries to link against to use Fontconfig.
+``Libsixel_INCLUDE_DIRS``
+  where to find the Fontconfig headers.
+``Libsixel_COMPILE_OPTIONS``
+  this should be passed to target_compile_options(), if the
+  target is not used for linking
+
+#]=======================================================================]
+
+find_package(PkgConfig QUIET)
+pkg_check_modules(PKG_LIBSIXEL QUIET libsixel)
+set(libsixel_COMPILE_OPTIONS ${PKG_LIBSIXEL_CFLAGS_OTHER})
+#set(libsixel_VERSION ${PKG_LIBSIXEL_VERSION})
+
+find_path(libsixel_INCLUDE_DIR
+  NAMES
+    sixel.h
+  HINTS
+    ${PKG_LIBSIXEL_INCLUDE_DIRS}
+)
+
+find_library(libsixel_LIBRARY
+  NAMES
+    sixel
+  PATHS
+    ${PKG_LIBSIXEL_LIBRARY_DIRS}
+)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(libsixel
+  FOUND_VAR
+    libsixel_FOUND
+  REQUIRED_VARS
+    libsixel_LIBRARY
+    libsixel_INCLUDE_DIR
+  VERSION_VAR
+    libsixel_VERSION
+)
+
+if(libsixel_FOUND AND NOT TARGET Libsixel::Libsixel)
+    add_library(Libsixel::Libsixel UNKNOWN IMPORTED)
+    set_target_properties(Libsixel::Libsixel PROPERTIES
+    IMPORTED_LOCATION "${libsixel_LIBRARY}"
+    INTERFACE_COMPILE_OPTIONS "${libsixel_COMPILE_OPTIONS}"
+    INTERFACE_INCLUDE_DIRECTORIES "${libsixel_INCLUDE_DIR}"
+  )
+endif()
+
+mark_as_advanced(libsixel_LIBRARY libsixel_INCLUDE_DIR)
+
+if(libsixel_FOUND)
+  set(libsixel_LIBRARIES ${libsixel_LIBRARY})
+  set(libsixel_INCLUDE_DIRS ${libsixel_INCLUDE_DIR})
+endif()

debian/control

@@ -13,6 +13,7 @@ Build-Depends:
   libharfbuzz-dev,
   libkf5windowsystem-dev,
   libqt5opengl5-dev,
+  libsixel-dev,
   libyaml-cpp-dev,
   make,
   ncurses-bin,
@@ -48,4 +49,5 @@ Depends: ${shlibs:Depends}, ${misc:Depends},
   libqt5core5a,
   libqt5gui5,
   libqt5network5,
+  libsixel1,
   libyaml-cpp0.6,

scripts/install-deps.sh

@@ -146,6 +146,7 @@ install_deps_ubuntu()
         libkf5windowsystem-dev
         libqt5gui5
         libqt5opengl5-dev
+        libsixel-dev
         libyaml-cpp-dev
         make
         ncurses-bin
@@ -200,6 +201,7 @@ install_deps_FreeBSD()
         freetype2 \
         harfbuzz \
         libfmt \
+        libsixel \
         microsoft-gsl \
         ncurses \
         ninja \
@@ -227,6 +229,7 @@ install_deps_arch()
         fontconfig \
         git \
         harfbuzz \
+        libsixel \
         microsoft-gsl \
         ninja \
         qt5-base \
@@ -240,6 +243,8 @@ install_deps_fedora()
     fetch_and_unpack_fmtlib
     [ x$PREPARE_ONLY_EMBEDS = xON ] && return
 
+    # TODO(pr) Houston we have a problem! Fedora does not like to have libsixel.
+
     # catch-devel
     local packages="
         catch-devel
@@ -275,6 +280,7 @@ install_deps_darwin()
         fmt \
         freetype \
         harfbuzz \
+        libsixel \
         pkg-config \
         range-v3 \
         qt@5 \

src/contour/CMakeLists.txt

@@ -9,6 +9,7 @@ option(CONTOUR_VT_METRICS "Enables collecting and exit-printing some VT usage me
 option(CONTOUR_SCROLLBAR "Enables scrollbar in GUI frontend." ON)
 option(CONTOUR_BLUR_PLATFORM_KWIN "Enables support for blurring transparent background when using KWin (KDE window manager)." OFF)
 option(CONTOUR_BUILD_WITH_QT6 "Use Qt 6" OFF)
+option(CONTOUR_COMMAND_IMAGE "Enables CLI command: contour image PATH_TO_IMAGE" OFF)
 
 if(CONTOUR_BUILD_WITH_QT6)
    find_package(Qt6 COMPONENTS Core Gui Network OpenGL OpenGLWidgets Widgets REQUIRED)
@@ -72,6 +73,12 @@ target_compile_definitions(contour PRIVATE
 set_target_properties(contour PROPERTIES AUTOMOC ON)
 set_target_properties(contour PROPERTIES AUTORCC ON)
 
+if(CONTOUR_COMMAND_IMAGE)
+    # This is (for now) by default disabled.
+    target_compile_definitions(contour PRIVATE CONTOUR_COMMAND_IMAGE)
+    find_package(libsixel REQUIRED)
+endif()
+
 if(CONTOUR_PERF_STATS)
     target_compile_definitions(contour PRIVATE CONTOUR_PERF_STATS)
 endif()
@@ -115,6 +122,11 @@ elseif(APPLE)
 endif()
 
 target_link_libraries(contour terminal yaml-cpp)
+
+if(CONTOUR_COMMAND_IMAGE)
+target_link_libraries(contour terminal Libsixel::Libsixel)
+endif()
+
 if(FREEBSD)
     # FreeBSD does not find yaml-cpp in /usr/local but weirdly everything else.
     target_link_directories(contour PUBLIC "/usr/local/lib")

src/contour/ContourApp.cpp

@@ -26,6 +26,8 @@
 #include <fmt/format.h>
 
 #include <QtCore/QFile>
+#include <QtCore/QMetaEnum>
+#include <QtGui/QImage>
 
 #include <chrono>
 #include <cstdio>
@@ -34,6 +36,16 @@
 #include <memory>
 #include <signal.h>
 
+#if defined(CONTOUR_COMMAND_IMAGE)
+    #if __has_include(<sixel/sixel.h>)
+        #include <sixel/sixel.h>
+        #define HAVE_SIXEL 1
+    #elif __has_include(<sixel.h>)
+        #include <sixel.h>
+        #define HAVE_SIXEL 1
+    #endif
+#endif
+
 #if !defined(_WIN32)
     #include <unistd.h>
 
@@ -167,6 +179,9 @@ ContourApp::ContourApp(): App("contour", "Contour Terminal Emulator", CONTOUR_VE
     link("contour.generate.terminfo", bind(&ContourApp::terminfoAction, this));
     link("contour.generate.config", bind(&ContourApp::configAction, this));
     link("contour.generate.integration", bind(&ContourApp::integrationAction, this));
+#if defined(CONTOUR_COMMAND_IMAGE)
+    link("contour.image", bind(&ContourApp::imageAction, this));
+#endif
 }
 
 template <typename Callback>
@@ -206,6 +221,93 @@ int ContourApp::integrationAction()
     });
 }
 
+#if defined(CONTOUR_COMMAND_IMAGE)
+int sixelWriter(char* data, int size, void* priv)
+{
+    cout.write(data, size);
+    return size;
+};
+#endif
+
+terminal::ImageSize terminalCellSize()
+{
+    using namespace terminal;
+#if !defined(_WIN32)
+    auto ws = winsize {};
+    if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == -1)
+        return {};
+
+    auto const viewSize = ImageSize { Width(ws.ws_xpixel), Height(ws.ws_ypixel) };
+    auto const pageSize = PageSize { LineCount(ws.ws_row), ColumnCount(ws.ws_col) };
+    auto const cellSize = viewSize / pageSize;
+    // fmt::print("cell size: {} / {} = {}\n", viewSize, pageSize, cellSize);
+    return cellSize;
+#else
+    return {};
+#endif
+}
+
+int ContourApp::imageAction()
+{
+#if defined(CONTOUR_COMMAND_IMAGE)
+    // Possible advanced options:
+    // - grid cell dimensions
+    // - image resize policy
+    // - image alignment policy
+    // - auto-scroll?
+    // - top-left position (or current cursor position)
+
+    auto const cellSize = terminalCellSize();
+    if (cellSize.area() == 0)
+    {
+        errorlog()("Could not detect terminal's grid cell size in pixels.");
+        return EXIT_FAILURE;
+    }
+
+    auto const filePath =
+        QString::fromUtf8(parameters().verbatim.front().data(), (int) parameters().verbatim.front().size());
+    auto qImage = QImage(filePath).convertToFormat(QImage::Format_RGB888);
+    if (qImage.format() != QImage::Format_RGB888)
+    {
+        errorlog()("Unsupported image format {} in file {}.",
+                   QMetaEnum::fromType<QImage::Format>().valueToKey(qImage.format()),
+                   filePath.toStdString());
+        return EXIT_FAILURE;
+    }
+
+    auto const requestedNumLines = parameters().uint("contour.image.lines");
+    auto const requestedNumColumns = parameters().uint("contour.image.columns");
+    if (requestedNumLines && requestedNumColumns)
+    {
+        auto const w = (int) (requestedNumColumns * cellSize.width.value);
+        auto const h = (int) (requestedNumLines * cellSize.height.value);
+        qImage = qImage.scaled(QSize(w, h));
+    }
+    else if (requestedNumLines)
+    {
+        auto const h = (int) (requestedNumLines * cellSize.height.value);
+        qImage = qImage.scaledToHeight(h);
+    }
+    else if (requestedNumColumns)
+    {
+        auto const w = (int) (requestedNumColumns * cellSize.width.value);
+        qImage = qImage.scaledToWidth(w);
+    }
+
+    auto const pixels = const_cast<unsigned char*>(qImage.constBits());
+    sixel_output_t* output = nullptr;
+    sixel_output_new(&output, &sixelWriter, nullptr, nullptr);
+    sixel_dither_t* dither = sixel_dither_get(SIXEL_BUILTIN_XTERM256);
+    sixel_encode(pixels, qImage.width(), qImage.height(), 3, dither, output);
+    sixel_dither_unref(dither);
+    sixel_output_destroy(output);
+    return EXIT_SUCCESS;
+#else
+    errorlog()("Feature was disabled at compile-time.");
+    return EXIT_FAILURE;
+#endif
+}
+
 int ContourApp::configAction()
 {
     withOutput(parameters(), "contour.generate.config.to", [](auto& _stream) {
@@ -273,6 +375,24 @@ crispy::cli::Command ContourApp::parameterDefinition() const
                            "Shows the license, and project URL of the used projects and Contour." },
             CLI::Command { "parser-table", "Dumps parser table" },
             CLI::Command { "list-debug-tags", "Lists all available debug tags and exits." },
+#if defined(CONTOUR_COMMAND_IMAGE)
+            CLI::Command {
+                "image",
+                "Sends an image to the terminal to render it at the current cursor position.",
+                CLI::OptionList {
+                    // might make sense to allow options in the future,
+                    // such as:
+                    // - grid cell dimensions
+                    // - image alignment policy
+                    // - image resize policy
+                    CLI::Option { "lines", CLI::Value { 0u }, "Number of grid lines this image shall span." },
+                    CLI::Option {
+                        "columns", CLI::Value { 0u }, "Number of grid columns this image shall span." },
+                },
+                CLI::CommandList {},
+                CLI::CommandSelect::Explicit,
+                CLI::Verbatim { "PATH", "Path to image to be sent." } },
+#endif
             CLI::Command {
                 "generate",
                 "Generation utilities.",

src/contour/ContourApp.h

@@ -36,6 +36,7 @@ class ContourApp: public crispy::App
     int terminfoAction();
     int configAction();
     int integrationAction();
+    int imageAction();
 };
 
 } // namespace contour

src/crispy/App.cpp

@@ -85,7 +85,8 @@ unsigned screenWidth()
 #if !defined(_WIN32)
     auto ws = winsize {};
     if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) != -1)
-        return ws.ws_col;
+        if (ws.ws_col != 0)
+            return ws.ws_col;
 #endif
 
     return DefaultWidth;

src/crispy/CLI.cpp

@@ -816,13 +816,12 @@ namespace // {{{ helpers
                 auto const& verbatim = _command.verbatim.value();
                 auto const leftSize =
                     static_cast<unsigned>(leftPadding.size() + 2 + verbatim.placeholder.size());
-                assert(columnWidth > leftSize);
-                auto const actualRightPaddingSize = columnWidth - leftSize;
+                auto const actualRightPaddingSize = columnWidth > leftSize ? columnWidth - leftSize : 2;
                 auto const left = leftPadding + stylize("[", HelpElement::Braces)
                                   + stylize(verbatim.placeholder, HelpElement::Verbatim)
                                   + stylize("]", HelpElement::Braces) + spaces(actualRightPaddingSize);
-
                 _os << left;
+
                 auto cursor = columnWidth + 1;
                 _os << stylize(wordWrapped(verbatim.helpText, columnWidth, _margin, &cursor),
                                HelpElement::HelpText);

src/terminal/primitives.h

@@ -465,6 +465,13 @@ constexpr ColumnOffset& operator-=(ColumnOffset& a, ColumnCount b) noexcept
     a.value -= b.value;
     return a;
 }
+
+constexpr ImageSize operator/(ImageSize viewSize, PageSize pageSize) noexcept
+{
+    return ImageSize { Width::cast_from(unbox<int>(viewSize.width) / unbox<int>(pageSize.columns)),
+                       Height::cast_from(unbox<int>(viewSize.height) / unbox<int>(pageSize.lines)) };
+}
+
 // }}}
 
 enum class ScreenType