Android: Add interface to handle interactions between delegate and QtView

Classes implementing QtEmbeddedViewConnector should support embedded
usecases for both Service and regular Activity embedding.

Any features that QtView requires from a delegate should be accessible
via this interface.

Task-number: QTBUG-118874
Change-Id: I238c6ef0451b1d08514c65f57e2875d31c5f4da9
Reviewed-by: Tinja Paavoseppä <tinja.paavoseppa@qt.io>

src/android/jar/CMakeLists.txt

@@ -38,6 +38,7 @@ set(java_sources
     src/org/qtproject/qt/android/QtEmbeddedDelegateFactory.java
     src/org/qtproject/qt/android/QtEmbeddedLoader.java
     src/org/qtproject/qt/android/QtView.java
+    src/org/qtproject/qt/android/QtEmbeddedViewInterface.java
 )
 
 qt_internal_add_jar(Qt${QtBase_VERSION_MAJOR}Android

src/android/jar/src/org/qtproject/qt/android/QtEmbeddedDelegate.java

@@ -21,7 +21,9 @@ import android.view.ViewGroup;
 import java.util.ArrayList;
 import java.util.HashMap;
 
-class QtEmbeddedDelegate extends QtActivityDelegateBase implements QtNative.AppStateDetailsListener {
+class QtEmbeddedDelegate extends QtActivityDelegateBase
+        implements QtNative.AppStateDetailsListener, QtEmbeddedViewInterface
+{
     // TODO simplistic implementation with one QtView, expand to support multiple views QTBUG-117649
     private QtView m_view;
     private QtNative.ApplicationStateDetails m_stateDetails;
@@ -126,6 +128,14 @@ class QtEmbeddedDelegate extends QtActivityDelegateBase implements QtNative.AppS
         return m_view.getQtWindow();
     }
 
+    // QtEmbeddedViewInterface implementation begin
+    @Override
+    public void startQtApplication(String appParams, String mainLib)
+    {
+        super.startNativeApplication(appParams, mainLib);
+    }
+
+    @Override
     public void queueLoadWindow()
     {
         synchronized (this) {
@@ -134,12 +144,15 @@ class QtEmbeddedDelegate extends QtActivityDelegateBase implements QtNative.AppS
         }
     }
 
-    void setView(QtView view) {
+    @Override
+    public void setView(QtView view)
+    {
         m_view = view;
         updateInputDelegate();
         if (m_view != null)
             registerGlobalFocusChangeListener(m_view);
     }
+    // QtEmbeddedViewInterface implementation end
 
     private void updateInputDelegate() {
         if (m_view == null) {

src/android/jar/src/org/qtproject/qt/android/QtEmbeddedViewInterface.java

@@ -0,0 +1,15 @@
+// Copyright (C) 2024 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+package org.qtproject.qt.android;
+
+/**
+ * QtEmbeddedViewInterface is intended to encapsulate the needs of QtView, so that the Activity and
+ * Service implementations of these functions may be split clearly, and the interface can be stored
+ * and used conveniently in QtView.
+**/
+interface QtEmbeddedViewInterface {
+    void startQtApplication(String appParams, String mainLib);
+    void setView(QtView view);
+    void queueLoadWindow();
+};

src/android/jar/src/org/qtproject/qt/android/QtView.java

@@ -31,7 +31,7 @@ abstract class QtView extends ViewGroup {
     protected long m_windowReference;
     protected long m_parentWindowReference;
     protected QtWindowListener m_windowListener;
-    protected QtEmbeddedDelegate m_delegate;
+    protected QtEmbeddedViewInterface m_viewInterface;
     // Implement in subclass to handle the creation of the QWindow and its parent container.
     // TODO could we take care of the parent window creation and parenting outside of the
     // window creation method to simplify things if user would extend this? Preferably without
@@ -60,7 +60,7 @@ abstract class QtView extends ViewGroup {
         }
 
         QtEmbeddedLoader loader = new QtEmbeddedLoader(context);
-        m_delegate = QtEmbeddedDelegateFactory.create((Activity)context);
+        m_viewInterface = QtEmbeddedDelegateFactory.create((Activity)context);
         loader.setMainLibraryName(appLibName);
         addOnLayoutChangeListener(new View.OnLayoutChangeListener() {
             @Override
@@ -80,22 +80,22 @@ abstract class QtView extends ViewGroup {
         });
         loader.loadQtLibraries();
         // Start Native Qt application
-        m_delegate.startNativeApplication(loader.getApplicationParameters(),
+        m_viewInterface.startQtApplication(loader.getApplicationParameters(),
                                            loader.getMainLibraryPath());
     }
 
     @Override
     protected void onAttachedToWindow() {
         super.onAttachedToWindow();
-        m_delegate.setView(this);
+        m_viewInterface.setView(this);
-        m_delegate.queueLoadWindow();
+        m_viewInterface.queueLoadWindow();
     }
 
     @Override
     protected void onDetachedFromWindow() {
         super.onDetachedFromWindow();
         destroyWindow();
-        m_delegate.setView(null);
+        m_viewInterface.setView(null);
     }
 
     @Override