Image support

Issue #5 and #7

deps/src/qmlwrap/CMakeLists.txt

@@ -31,6 +31,8 @@ endif(WIN32)
 add_library(qmlwrap SHARED
   julia_api.hpp
   julia_api.cpp
+  julia_display.hpp
+  julia_display.cpp
   julia_object.hpp
   julia_object.cpp
   julia_signals.hpp

deps/src/qmlwrap/julia_api.cpp

@@ -44,7 +44,7 @@ QVariant JuliaAPI::call(const QString& fname, const QVariantList& args)
   result = jl_call(func, julia_args, nb_args);
   if (jl_exception_occurred())
   {
-    qWarning() << "Exception in Julia callback " << fname << ": " << QString(cxx_wrap::julia_type_name((jl_datatype_t*)jl_typeof(jl_exception_occurred())).c_str()) << ": " << jl_string_data(jl_fieldref(jl_exception_occurred(),0));
+    qWarning() << "Exception in Julia callback " << fname << ": " << QString(cxx_wrap::julia_type_name((jl_datatype_t*)jl_typeof(jl_exception_occurred())).c_str());// << ": " << jl_string_data(jl_fieldref(jl_exception_occurred(),0));
     JL_GC_POP();
     JL_GC_POP();
     return QVariant();

deps/src/qmlwrap/julia_display.cpp

@@ -0,0 +1,46 @@
+#include <QDebug>
+#include <QPainter>
+
+#include "julia_display.hpp"
+namespace qmlwrap
+{
+
+JuliaDisplay::JuliaDisplay(QQuickItem *parent) : QQuickPaintedItem(parent)
+{
+}
+
+void JuliaDisplay::paint(QPainter *painter)
+{
+  painter->drawPixmap(0,0,m_pixmap);
+}
+
+void JuliaDisplay::load_png(cxx_wrap::ArrayRef<unsigned char> data)
+{
+  if(m_pixmap.isNull())
+  {
+    clear();
+  }
+  if(!m_pixmap.loadFromData(data.data(), data.size(), "PNG"))
+  {
+    qWarning() << "Failed to load PNG data";
+    clear();
+  }
+  update();
+}
+
+void JuliaDisplay::clear()
+{
+  m_pixmap = QPixmap(width(), height());
+  m_pixmap.fill(Qt::transparent);
+}
+
+void JuliaDisplay::geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry)
+{
+  QQuickPaintedItem::geometryChanged(newGeometry, oldGeometry);
+  if(newGeometry != oldGeometry)
+  {
+    clear();
+  }
+}
+
+} // namespace qmlwrap

deps/src/qmlwrap/julia_display.hpp

@@ -0,0 +1,36 @@
+#ifndef QML_JULIA_DISPLAY_H
+#define QML_JULIA_DISPLAY_H
+
+#include <cxx_wrap.hpp>
+
+#include <QObject>
+#include <QPixmap>
+#include <QQuickPaintedItem>
+
+namespace qmlwrap
+{
+
+/// Groups signals (defined using QML) that can be emitted from Julia
+class JuliaDisplay : public QQuickPaintedItem
+{
+  Q_OBJECT
+
+public:
+  JuliaDisplay(QQuickItem *parent = 0);
+
+  void paint(QPainter *painter);
+
+  void load_png(cxx_wrap::ArrayRef<unsigned char> data);
+
+  void clear();
+
+protected:
+  void geometryChanged(const QRectF &newGeometry, const QRectF &oldGeometry);
+
+private:
+  QPixmap m_pixmap;
+};
+
+} // namespace qmlwrap
+
+#endif

deps/src/qmlwrap/type_conversion.cpp

@@ -2,6 +2,7 @@
 #include <QFileInfo>
 #include <QUrl>
 
+#include "julia_display.hpp"
 #include "julia_object.hpp"
 #include "type_conversion.hpp"
 
@@ -59,17 +60,22 @@ jl_value_t* convert_to_julia<QString>(const QVariant& v)
   return nullptr;
 }
 
-template<typename... TypesT>
+template<int T = 0>
+jl_value_t* try_qobject_cast(QObject* o)
+{
+  qWarning() << "got unknown QObject* type in QVariant conversion: " << o->metaObject()->className();
+  return nullptr;
+}
+
+template<typename Type1, typename... TypesT>
 jl_value_t* try_qobject_cast(QObject* o)
 {
-  for(auto* cast_o : {qobject_cast<TypesT*>(o)...})
+  Type1* cast_o = qobject_cast<Type1*>(o);
   {
     if(cast_o != nullptr)
       return cxx_wrap::convert_to_julia(cast_o);
+    return try_qobject_cast<TypesT...>(o);
   }
-
-  qWarning() << "got unknown QObject* type in QVariant conversion: " << o->metaObject()->className();
-  return nullptr;
 }
 
 // QObject*
@@ -78,7 +84,8 @@ jl_value_t* convert_to_julia<QObject*>(const QVariant& v)
 {
   if(v.type() == qMetaTypeId<QObject*>())
   {
-    return try_qobject_cast<JuliaObject>(v.value<QObject*>());
+    // Add new types here
+    return try_qobject_cast<JuliaObject, JuliaDisplay>(v.value<QObject*>());
   }
 
   return nullptr;

deps/src/qmlwrap/wrap_qml.cpp

@@ -9,6 +9,7 @@
 #include <QtQml>
 
 #include "julia_api.hpp"
+#include "julia_display.hpp"
 #include "julia_object.hpp"
 #include "julia_signals.hpp"
 #include "type_conversion.hpp"
@@ -43,6 +44,7 @@ JULIA_CPP_MODULE_BEGIN(registry)
 
   qmlRegisterSingletonType("org.julialang", 1, 0, "Julia", qmlwrap::julia_js_singletontype_provider);
   qmlRegisterType<qmlwrap::JuliaSignals>("org.julialang", 1, 0, "JuliaSignals");
+  qmlRegisterType<qmlwrap::JuliaDisplay>("org.julialang", 1, 0, "JuliaDisplay");
 
   qml_module.add_abstract<QObject>("QObject");
 
@@ -145,6 +147,9 @@ JULIA_CPP_MODULE_BEGIN(registry)
     }
   });
 
+  qml_module.add_type<qmlwrap::JuliaDisplay>("JuliaDisplay", julia_type("CppDisplay"))
+    .method("load_png", &qmlwrap::JuliaDisplay::load_png);
+
   // Exports:
-  qml_module.export_symbols("QApplication", "QQmlApplicationEngine", "QQmlContext", "set_context_property", "root_context", "load", "qt_prefix_path", "QQuickView", "set_source", "engine", "QByteArray", "QQmlComponent", "set_data", "create", "QQuickItem", "content_item", "QQuickWindow", "QQmlEngine", "JuliaObject", "QTimer", "context_property", "emit");
+  qml_module.export_symbols("QApplication", "QQmlApplicationEngine", "QQmlContext", "set_context_property", "root_context", "load", "qt_prefix_path", "QQuickView", "set_source", "engine", "QByteArray", "QQmlComponent", "set_data", "create", "QQuickItem", "content_item", "QQuickWindow", "QQmlEngine", "JuliaObject", "QTimer", "context_property", "emit", "JuliaDisplay");
 JULIA_CPP_MODULE_END

src/QML.jl

@@ -68,6 +68,12 @@ macro qmlfunction(fname...)
   esc(:(QML.register_function($(Any[string(f) for f in fname]))))
 end
 
+function Base.display(d::JuliaDisplay, x)
+  buf = IOBuffer()
+  writemime(buf, MIME"image/png"(), x)
+  load_png(d, takebuf_array(buf))
+end
+
 export @qmlget, @qmlset, @emit, @qmlfunction
 
 @doc """

test/image.jl

@@ -0,0 +1,24 @@
+using Base.Test
+using QML
+using TestImages
+
+function test_display(d::JuliaDisplay)
+  img = testimage("lena_color_256")
+  display(d, img)
+end
+
+@qmlfunction test_display
+
+qml_file = joinpath(Pkg.dir("QML"), "test", "qml", "image.qml")
+
+app = QML.application()
+qml_engine4 = QQmlApplicationEngine()
+
+# Load QML after setting context properties, to avoid errors
+load(qml_engine4, qml_file)
+
+# Run the application
+QML.exec()
+
+# Needed to prevent crash-on-exit
+finalize(app)

test/qml/image.qml

@@ -0,0 +1,28 @@
+import QtQuick 2.0
+import QtQuick.Controls 1.0
+import QtQuick.Layouts 1.0
+import org.julialang 1.0
+
+ApplicationWindow {
+  title: "My Application"
+  width: 300
+  height: 300
+  visible: true
+
+  ColumnLayout {
+    spacing: 6
+    anchors.centerIn: parent
+
+    Button {
+      Layout.alignment: Qt.AlignCenter
+      text: "Push Me"
+      onClicked: Julia.test_display(jdisp)
+    }
+
+    JuliaDisplay {
+      id: jdisp
+      width: 256
+      height: 256
+    }
+  }
+}

test/runtests.jl

@@ -4,3 +4,4 @@ include("qquickview.jl")
 include("qqmlcomponent.jl")
 include("julia_object.jl")
 include("julia_signal.jl")
+include("image.jl")