Transforming preview sample, with injection. This way I can connect my CVCamera object to other objects in the cpp part of the code.

.gitignore

@@ -1,10 +1,81 @@
-#Temp build files
-*.pyc
-build*/
-
-#Temp QT files
-*.user
+# This file is used to ignore files which are generated
+# ----------------------------------------------------------------------------
 
-#Annoying files
 *~
+*.autosave
+*.a
+*.core
+*.moc
+*.o
+*.obj
+*.orig
+*.rej
+*.so
+*.so.*
+*_pch.h.cpp
+*_resource.rc
+*.qm
+.#*
+*.*#
+core
+!core/
+tags
+.DS_Store
+.directory
+*.debug
+Makefile*
+*.prl
+*.app
+moc_*.cpp
+ui_*.h
+qrc_*.cpp
+Thumbs.db
+*.res
+*.rc
+/.qmake.cache
+/.qmake.stash
+
+# qtcreator generated files
+*.pro.user*
+
+# xemacs temporary files
+*.flc
+
+# Vim temporary files
+.*.swp
+
+# Visual Studio generated files
+*.ib_pdb_index
+*.idb
+*.ilk
+*.pdb
+*.sln
+*.suo
+*.vcproj
+*vcproj.*.*.user
+*.ncb
+*.sdf
+*.opensdf
+*.vcxproj
+*vcxproj.*
+
+# MinGW generated files
+*.Debug
+*.Release
+
+# Python byte code
+*.pyc
+
+# Binaries
+# --------
+*.dll
+*.exe
+build-android-*
+build-macos-*
+*.txt.user
+*.pro.user
 
+m/
+q/
+*build-preview*
+# No Wasm because QtMultimedia is not implemented yet. 

qml-cvcamera.pro

@@ -27,7 +27,8 @@ SOURCES += \
     src/CameraThread.cpp \
     src/BetterVideoCapture.cpp
 
-LIBS += -lopencv_core -lopencv_highgui -lopencv_imgproc -lopencv_videoio
+INCLUDEPATH += $$(OPENCV_DIR)/include/opencv4
+LIBS += -L$$(OPENCV_DIR)/lib -lopencv_core -lopencv_highgui -lopencv_imgproc -lopencv_videoio
 
 android {
     HEADERS += \

samples/preview/preview.pro

@@ -6,6 +6,12 @@ SOURCES += src/main.cpp
 
 RESOURCES += qml.qrc
 
+INCLUDEPATH += $$(OPENCV_DIR)/include/opencv4
+INCLUDEPATH += ../../src
+LIBS += -L$$(OPENCV_DIR)/lib -lopencv_core -lopencv_highgui -lopencv_imgproc -lopencv_videoio
+LIBS += -L/Users/jg/Code/opensource/qt/5.12.3/clang_64/qml/CVCamera/ -lcvcameraplugin
+
+
 android {
     target.path = /libs/armeabi-v7a
     export(target.path)

samples/preview/src/main.cpp

@@ -1,3 +1,6 @@
+#include <QSize>
+#include <CVCamera.h>
+#include <QQmlContext>
 #include <QGuiApplication>
 #include <QQmlApplicationEngine>
 
@@ -6,6 +9,16 @@ int main(int argc, char *argv[])
     QGuiApplication app(argc, argv);
 
     QQmlApplicationEngine engine;
+
+    //Instantiate Camera.
+    CVCamera camera;
+    camera.setSize(QSize(640,480));
+
+
+
+    auto qmlContext = engine.rootContext();
+    qmlContext->setContextProperty("camerax", &camera);
+
     engine.load(QUrl(QStringLiteral("qrc:/src/main.qml")));
 
     return app.exec();

samples/preview/src/main.qml

@@ -1,28 +1,23 @@
 import QtQuick 2.2
 import QtQuick.Window 2.1
-import QtQuick.Controls 1.2
+import QtQuick.Controls 2.5
 import QtMultimedia 5.0
-import CVCamera 1.0
 
-Window {
+ApplicationWindow {
     visible: true
 
     //Width and height stuff is for desktop only, they seem to be ignored on Android (this is expected good behavior)
-    width: camera.size.width
-    height: camera.size.height
-    maximumHeight: camera.size.height
-    maximumWidth: camera.size.width
+    width: camerax.size.width
+    height: camerax.size.height
+    maximumHeight: camerax.size.height
+    maximumWidth: camerax.size.width
 
-    CVCamera {
-        id: camera
-        device: deviceBox.currentIndex
-        size: "640x480"
-    }
+
 
     VideoOutput {
         anchors.top: imageSizeField.top
         id: output
-        source: camera
+        source: camerax
     }
 
     TextField {
@@ -42,6 +37,6 @@ Window {
         id: deviceBox
         width: 200
         anchors.left: imageSizeSetButton.right
-        model: camera.deviceList
+        model: camerax.deviceList
     }
 }