Android: Add docs to QtQuickView class

Add descriptions to public methods and interfaces of the QtQuickView.

Task-number: QTBUG-120718
Change-Id: Ieffbd6b69be1cb4fe41839793343cac6a02229bd
Reviewed-by: Tinja Paavoseppä <tinja.paavoseppa@qt.io>
Reviewed-by: Rami Potinkara <rami.potinkara@qt.io>
Reviewed-by: Assam Boudjelthia <assam.boudjelthia@qt.io>
(cherry picked from commit e05ccb11db464df76640766f42b13f1d15f07ae9)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit 337d721a215639fbddef3685fb0b88192c9e5a98)

1 files changed, 144 insertions, 2 deletions

diff --git a/src/quick/jar/org/qtproject/qt/android/QtQuickView.java b/src/quick/jar/org/qtproject/qt/android/QtQuickView.java
index 16bac58c16..76b19e36ee 100644
--- a/src/quick/jar/org/qtproject/qt/android/QtQuickView.java
+++ b/src/quick/jar/org/qtproject/qt/android/QtQuickView.java
@@ -10,23 +10,74 @@ import android.util.Log;
 
 import java.security.InvalidParameterException;
 
+/**
+ * The QtQuickView class lets you easily add QML content to your Android app as a
+ * {@link android.view.View View}. QtQuickView instantiates a QQuickView with a given
+ * QML component source URI path and embeds it inside itself. You can add it in your Android app's
+ * layout as with any other View. QtQuickView is a good choice when you want to extend your non-Qt
+ * Android app with QML content but do not want to make the entire app using the Qt framework.
+ * It brings the power of Qt Quick into your Android app, making it possible to use various Qt Quick
+ * APIs, in Android Java or Kotlin apps.
+ * </p>
+ * <b>Note:</b> This class is a technical preview. It is subject to change, and no source nor
+ * binary compatibility guarantees exist.
+ * <p>
+ * <b>Known limitations:</b>
+ * <p><ul>
+ * <li> Only CMake is supported, not qmake.
+ * <li> Only one QtQuickView can be added to your app, adding multiple outcomes unknown.
+ * </ul><p>
+ * @see <a href="https://doc.qt.io/qt-6/qquickview.html">Qt QQuickView</a>
+ **/
 public class QtQuickView extends QtView {
     private final static String TAG = "QtQuickView";
 
+    /**
+     * A callback that notifies clients when a signal is emitted from the QML root object.
+     **/
     @FunctionalInterface
     public interface SignalListener<T>
     {
+        /**
+        * Called on the Android UI thread when the signal has been emitted.
+        * @param signalName literal signal name
+        * @param value the value delivered by the signal or null if the signal is parameterless
+        **/
         void onSignalEmitted(String signalName, T value);
     }
 
+    /**
+    * A callback that notifies clients about the status of QML loading.
+    **/
     public interface StatusChangeListener
     {
+        /**
+        * Called on the Android UI thread when the QML component status has changed.
+        * @param status The current status. The status can be STATUS_NULL, STATUS_READY,
+        *        STATUS_LOADING or STATUS_ERROR.
+        **/
         void onStatusChanged(int status);
     }
 
+    /**
+     * QML loading status: No source is set or the root object has not been created yet.
+     **/
     public static final int STATUS_NULL = 0;
+    /**
+     * QML loading status: The QML view is loaded and the root object is available.
+     * Invoking methods that operate on the QML root object, i.e.
+     * {@link QtQuickView#setProperty() setProperty}, {@link QtQuickView#getProperty() getProperty},
+     * and {@link QtQuickView#addSignalListener() addSignalListener} would succeed <b>only<b> if
+     * the current status is ready.
+     **/
     public static final int STATUS_READY = 1;
+    /**
+    * QML loading status: The QML view is loading the root object from network.
+    **/
     public static final int STATUS_LOADING = 2;
+    /**
+    * QML loading status: One or more errors has occurred.
+    **/
     public static final int STATUS_ERROR = 3;
 
     private String m_qmlUri;
@@ -43,11 +94,38 @@ public class QtQuickView extends QtView {
                                           Object listener);
     native boolean removeRootObjectSignalListener(long windowReference, int signalListenerId);
 
+    /**
+     * Creates a QtQuickView to load and view a QML component. Instantiating a QtQuickView will load
+     * the Qt libraries, including the app library specified by <code>appName</code>. Then it
+     * creates a QQuickView that loads the QML source specified by <code>qmlUri</code>.
+     * <p>
+     * @param context the parent Context
+     * @param qmlUri  the URI of the main QML file
+     * @param appName the name of the Qt app library to load and start. This corresponds to the
+     *                target name set in Qt app's CMakeLists.txt
+     * @throws InvalidParameterException if either qmlUri or appName is empty or null
+     * @see <a href="https://doc.qt.io/qt-6/qquickview.html">Qt QQuickView</a>
+     **/
     public QtQuickView(Context context, String qmlUri, String appName)
         throws InvalidParameterException {
         this(context, qmlUri, appName, null);
     }
 
+    /**
+     * Creates a QtQuickView to load and view a QML component. Instantiating a QtQuickView will load
+     * the Qt libraries, including the app library specified by appName. Then it creates a
+     * QQuickView that loads the QML source specified by qmlUri. This overload accepts an array of
+     * strings in the case where the QML application should load QML modules from custom paths.
+     * <p>
+     * @param context        the parent Context
+     * @param qmlUri         the URI of the main QML file
+     * @param appName        the name of the Qt app library to load and start. This corresponds to
+     *                       the target name set in the Qt app's CMakeLists.txt
+     * @param qmlImportPaths an array of strings for additional import paths to be passed to
+                             QQmlEngine, or null if additional import paths are not required
+     * @throws InvalidParameterException if either qmlUri or appName is empty or null
+     * @see <a href="https://doc.qt.io/qt-6/qqmlengine.html">Qt QQmlEngine</a>
+     **/
     public QtQuickView(Context context, String qmlUri, String appName, String[] qmlImportPaths)
             throws InvalidParameterException
     {
@@ -65,11 +143,40 @@ public class QtQuickView extends QtView {
         createQuickView(m_qmlUri, getWidth(), getHeight(), parentWindowReference, m_qmlImportPaths);
     }
 
+    /**
+     * Sets the value of an existing property on the QML root object. The supported types are
+     * {@link java.lang.Integer}, {@link java.lang.Double}, {@link java.lang.Float},
+     * {@link java.lang.Boolean} and {@link java.lang.String}. These types get converted to their
+     * corresponding QML types int, double/float, bool and string. This function does not add
+     * properties to the QML root object if they do not exist, but prints a warning.
+     * <p>
+     * @param propertyName the name of the existing root object property to set the value of
+     * @param value        the value to set the property to
+     * @see <a href="https://doc.qt.io/qt-6/qml-int.html">QML int</a>,
+     * @see <a href="https://doc.qt.io/qt-6/qml-double.html">QML double/float</a>,
+     * @see <a href="https://doc.qt.io/qt-6/qml-bool.html">QML bool</a>,
+     * @see <a href="https://doc.qt.io/qt-6/qml-string.html">QML string</a>.
+     **/
     public void setProperty(String propertyName, Object value)
     {
         setRootObjectProperty(windowReference(), propertyName, value);
     }
 
+    /**
+     * Gets the value of an existing property of the QML root object. The supported types are
+     * {@link java.lang.Integer}, {@link java.lang.Double}, {@link java.lang.Float},
+     * {@link java.lang.Boolean} and {@link java.lang.String}. These types get converted to their
+     * corresponding QML types int, double/float, bool and string. If the property does not
+     * exist or the status of the QML component is anything other than
+     * {@link QtQuickView#STATUS_READY STATUS_READY}, this function will return null.
+     * <p>
+     * @param propertyName the name of the existing root object property
+     * @throws ClassCastException if the returned type could not be casted to the requested type.
+     * @see <a href="https://doc.qt.io/qt-6/qml-int.html">QML int</a>,
+     * @see <a href="https://doc.qt.io/qt-6/qml-double.html">QML double/float</a>,
+     * @see <a href="https://doc.qt.io/qt-6/qml-bool.html">QML bool</a>,
+     * @see <a href="https://doc.qt.io/qt-6/qml-string.html">QML string</a>.
+     **/
     // getRootObjectProperty always returns a primitive type or an Object
     // so it is safe to suppress the unchecked warning
     @SuppressWarnings("unchecked")
@@ -78,28 +185,63 @@ public class QtQuickView extends QtView {
         return (T)getRootObjectProperty(windowReference(), propertyName);
     }
 
+    /**
+     * Connects a SignalListener to a signal of the QML root object.
+     * <p>
+     * @param signalName the name of the root object signal
+     * @param argType    the Class type of the signal argument
+     * @param listener   an instance of the SignalListener interface
+     * @return a connection id between signal and listener or the existing connection id if there is
+     *         an existing connection between the same signal and listener. Return a negative value
+     *         if the signal does not exists on the QML root object.
+     **/
     public <T> int connectSignalListener(String signalName, Class<T> argType,
                                     SignalListener<T> listener)
     {
         int signalListenerId =
                 addRootObjectSignalListener(windowReference(), signalName, argType, listener);
         if (signalListenerId < 0) {
-            Log.w(TAG, "The signal " + signalName
-                     + " does not exist in the root object or the arguments do not match with the listener.");
+            Log.w(TAG, "The signal " + signalName + " does not exist in the root object "
+                                     + "or the arguments do not match with the listener.");
         }
         return signalListenerId;
     }
 
+    /**
+     * Disconnects a SignalListener with a given id obtained from
+     * {@link QtQuickView#connectSignalListener() connectSignalListener} call, from listening to
+     * a signal.
+     * <p>
+     * @param signalListenerId the connection id
+     * @return Returns true if the connection id is valid and has been successfuly removed,
+     *         otherwise returns false.
+     **/
     public boolean disconnectSignalListener(int signalListenerId)
     {
         return removeRootObjectSignalListener(windowReference(), signalListenerId);
     }
 
+    /**
+     * Gets the status of the QML component.
+     * <p>
+     * @return Returns STATUS_READY when the QML component is ready. Invoking methods that operate
+     *         on the QML root object ({@link QtQuickView#setProperty() setProperty},
+     *         {@link QtQuickView#getProperty() getProperty}, and
+     *         {@link QtQuickView#addSignalListener() addSignalListener}) would succeed <b>only</b>
+     *         if the current STATUS_READY. It can also return STATUS_NULL, STATUS_LOADING, or
+     *         STATUS_ERROR based on the status of see underlaying
+     *         @see <a href="https://doc.qt.io/qt-6/qquickview.html">QQuickView</a> instance.
+     **/
     public int getStatus()
     {
         return m_lastStatus;
     }
 
+    /**
+     * Sets a StatusChangeListener to listen to status changes.
+     * <p>
+     * @param listener an instance of a StatusChangeListener interface
+     **/
     public void setStatusChangeListener(StatusChangeListener listener)
     {
         m_statusChangeListener = listener;