From 182789999441f7c812a7b15ddb7660a3966fb4f1 Mon Sep 17 00:00:00 2001
From: Will <1305536+zflat@users.noreply.github.com>
Date: Thu, 2 Dec 2021 02:19:36 -0500
Subject: [PATCH] Use qmldir to define QML module with IgnSpinBox (#319)

Signed-off-by: William Wedler <william.wedler@resquared.com>
Co-authored-by: Louise Poubel <louise@openrobotics.org>
---
 include/ignition/gui/Helpers.hh    | 10 ++++++++++
 include/ignition/gui/qml/qmldir    |  3 +++
 include/ignition/gui/resources.qrc |  6 ++++++
 src/Application.cc                 |  2 ++
 src/Helpers.cc                     |  6 ++++++
 src/plugins/teleop/Teleop.qml      |  2 +-
 6 files changed, 28 insertions(+), 1 deletion(-)
 create mode 100644 include/ignition/gui/qml/qmldir

diff --git a/include/ignition/gui/Helpers.hh b/include/ignition/gui/Helpers.hh
index 2a22abf0d..a83e7fa51 100644
--- a/include/ignition/gui/Helpers.hh
+++ b/include/ignition/gui/Helpers.hh
@@ -79,6 +79,16 @@ namespace ignition
     IGNITION_GUI_VISIBLE
     QStringList worldNames();
 
+
+    /// \brief Import path for ign-gui QML modules added to the Qt resource system
+    /// This helper function returns the QRC resource path where custom ignition QML
+    /// modules can be imported from. To import an ignition QML module, add this path
+    /// to the QML engine's import path list before attempting to load a QML file
+    /// that imports ignition QML modules.
+    /// \return Resousrce path prefix as a string
+    IGNITION_GUI_VISIBLE
+    const QString qmlQrcImportPath();
+
     /// \brief Returns the first element on a QList which matches the given
     /// property.
     /// \param[in] _list The list to search through.
diff --git a/include/ignition/gui/qml/qmldir b/include/ignition/gui/qml/qmldir
new file mode 100644
index 000000000..f4f66ebc1
--- /dev/null
+++ b/include/ignition/gui/qml/qmldir
@@ -0,0 +1,3 @@
+module ignition.gui
+
+IgnSpinBox 1.0 IgnSpinBox.qml
\ No newline at end of file
diff --git a/include/ignition/gui/resources.qrc b/include/ignition/gui/resources.qrc
index fd0cb74ce..934624c10 100644
--- a/include/ignition/gui/resources.qrc
+++ b/include/ignition/gui/resources.qrc
@@ -20,4 +20,10 @@
   <file>qml/images/menu.png</file>
   <file>qml/images/search.svg</file>
 </qresource>
+<qresource prefix="ign-gui-qml/ignition/gui">
+    <!-- This qmldir file defines a QML module that can be imported -->
+    <file alias="qmldir">qml/qmldir</file>
+    <!-- Add any QML components referenced in the qmldir file here -->
+    <file alias="IgnSpinBox.qml">qml/IgnSpinBox.qml</file>
+</qresource>
 </RCC>
diff --git a/src/Application.cc b/src/Application.cc
index ac60ce07a..6ca02efd8 100644
--- a/src/Application.cc
+++ b/src/Application.cc
@@ -28,6 +28,7 @@
 #include "ignition/gui/Application.hh"
 #include "ignition/gui/config.hh"
 #include "ignition/gui/Dialog.hh"
+#include "ignition/gui/Helpers.hh"
 #include "ignition/gui/MainWindow.hh"
 #include "ignition/gui/Plugin.hh"
 
@@ -91,6 +92,7 @@ Application::Application(int &_argc, char **_argv, const WindowType _type)
 
   // QML engine
   this->dataPtr->engine = new QQmlApplicationEngine();
+  this->dataPtr->engine->addImportPath(qmlQrcImportPath());
 
   // Install signal handler for graceful shutdown
   this->dataPtr->signalHandler.AddCallback(
diff --git a/src/Helpers.cc b/src/Helpers.cc
index 4c6a51329..0fc89d7cc 100644
--- a/src/Helpers.cc
+++ b/src/Helpers.cc
@@ -180,3 +180,9 @@ QStringList ignition::gui::worldNames()
 
   return worldNamesVariant.toStringList();
 }
+
+/////////////////////////////////////////////////
+const QString ignition::gui::qmlQrcImportPath()
+{
+  return "qrc:/ign-gui-qml/";
+}
diff --git a/src/plugins/teleop/Teleop.qml b/src/plugins/teleop/Teleop.qml
index 74f9eed9d..f4001a578 100644
--- a/src/plugins/teleop/Teleop.qml
+++ b/src/plugins/teleop/Teleop.qml
@@ -20,7 +20,7 @@ import QtQuick.Controls 2.2
 import QtQuick.Controls.Material 2.1
 import QtQuick.Controls.Styles 1.4
 import QtQuick.Layouts 1.3
-import "qrc:/qml"
+import ignition.gui 1.0
 
 Rectangle {
   color:"transparent"