Do not initialize accessibility code by default on startup.

Instead listen for if the accessibility service is running or not by
implementing AccessibilityStateChangeListener.
This seems to work smoothly when turning on or off TalkBack.

This should also improve startup time.

Change-Id: I3eb7d6cb9c9c1618afbb59675e4e089c9159019c
Reviewed-by: Christian Stromme <christian.stromme@theqtcompany.com>

2 files changed, 69 insertions, 8 deletions

diff --git a/src/android/accessibility/jar/jar.pri b/src/android/accessibility/jar/jar.pri
index 23b3ff7087..3ae9fed59d 100644
--- a/src/android/accessibility/jar/jar.pri
+++ b/src/android/accessibility/jar/jar.pri
@@ -4,7 +4,8 @@ API_VERSION = android-16
 
 PATHPREFIX = $$PWD/src/org/qtproject/qt5/android/accessibility
 
-JAVACLASSPATH += $$PWD/src/
+JAVACLASSPATH += $$PWD/src/ \
+                 $$DESTDIR/QtAndroid-bundled.jar
 JAVASOURCES += \
     $$PATHPREFIX/QtAccessibilityDelegate.java \
     $$PATHPREFIX/QtNativeAccessibility.java
diff --git a/src/android/accessibility/jar/src/org/qtproject/qt5/android/accessibility/QtAccessibilityDelegate.java b/src/android/accessibility/jar/src/org/qtproject/qt5/android/accessibility/QtAccessibilityDelegate.java
index a4626b9bb1..cc2aba7937 100644
--- a/src/android/accessibility/jar/src/org/qtproject/qt5/android/accessibility/QtAccessibilityDelegate.java
+++ b/src/android/accessibility/jar/src/org/qtproject/qt5/android/accessibility/QtAccessibilityDelegate.java
@@ -43,6 +43,7 @@
 package org.qtproject.qt5.android.accessibility;
 
 import android.accessibilityservice.AccessibilityService;
+import android.app.Activity;
 import android.graphics.Rect;
 import android.os.Bundle;
 import android.util.Log;
@@ -60,6 +61,8 @@ import android.content.Context;
 import java.util.LinkedList;
 import java.util.List;
 
+import org.qtproject.qt5.android.QtActivityDelegate;
+
 public class QtAccessibilityDelegate extends View.AccessibilityDelegate
 {
     private static final String TAG = "Qt A11Y";
@@ -72,8 +75,11 @@ public class QtAccessibilityDelegate extends View.AccessibilityDelegate
     // Pretend to be an inner class of the QtSurface.
     private static final String DEFAULT_CLASS_NAME = "$VirtualChild";
 
-    private final View m_view;
-    private final AccessibilityManager m_manager;
+    private View m_view = null;
+    private AccessibilityManager m_manager;
+    private QtActivityDelegate m_activityDelegate;
+    private Activity m_activity;
+    private ViewGroup m_layout;
 
     // The accessible object that currently has the "accessibility focus"
     // usually indicated by a yellow rectangle on screen.
@@ -95,17 +101,71 @@ public class QtAccessibilityDelegate extends View.AccessibilityDelegate
         }
     }
 
-    public QtAccessibilityDelegate(View host)
+    public QtAccessibilityDelegate(Activity activity, ViewGroup layout, QtActivityDelegate activityDelegate)
     {
-        m_view = host;
-        m_view.setOnHoverListener(new HoverEventListener());
-        m_manager = (AccessibilityManager) host.getContext()
-                .getSystemService(Context.ACCESSIBILITY_SERVICE);
+        m_activity = activity;
+        m_layout = layout;
+        m_activityDelegate = activityDelegate;
+
+        m_manager = (AccessibilityManager) m_activity.getSystemService(Context.ACCESSIBILITY_SERVICE);
+        if (m_manager != null) {
+            AccessibilityManagerListener accServiceListener = new AccessibilityManagerListener();
+            if (!m_manager.addAccessibilityStateChangeListener(accServiceListener))
+                Log.w("Qt A11y", "Could not register a11y state change listener");
+            if (m_manager.isEnabled())
+                accServiceListener.onAccessibilityStateChanged(true);
+        }
+
 
         // Enable Qt Accessibility so that notifications are enabled
         QtNativeAccessibility.setActive(true);
     }
 
+    private class AccessibilityManagerListener implements AccessibilityManager.AccessibilityStateChangeListener
+    {
+        @Override
+        public void onAccessibilityStateChanged(boolean enabled)
+        {
+            if (enabled) {
+                // The accessibility code depends on android API level 16, so dynamically resolve it
+                if (android.os.Build.VERSION.SDK_INT >= 16) {
+                    try {
+                        View view = m_view;
+                        if (view == null) {
+                            view = new View(m_activity);
+                            view.setId(View.NO_ID);
+                        }
+
+                        // ### Keep this for debugging for a while. It allows us to visually see that our View
+                        // ### is on top of the surface(s)
+                        // ColorDrawable color = new ColorDrawable(0x80ff8080);    //0xAARRGGBB
+                        // view.setBackground(color);
+                        view.setAccessibilityDelegate(QtAccessibilityDelegate.this);
+
+                        // if all is fine, add it to the layout
+                        if (m_view == null) {
+                            //m_layout.addAccessibilityView(view);
+                            m_layout.addView(view, m_activityDelegate.getSurfaceCount(),
+                                             new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
+                        }
+                        m_view = view;
+
+                        m_view.setOnHoverListener(new HoverEventListener());
+                    } catch (Exception e) {
+                        // Unknown exception means something went wrong.
+                        Log.w("Qt A11y", "Unknown exception: " + e.toString());
+                    }
+                }
+            } else {
+                if (m_view != null) {
+                    m_layout.removeView(m_view);
+                    m_view = null;
+                }
+            }
+        }
+    }
+
+
     @Override
     public AccessibilityNodeProvider getAccessibilityNodeProvider(View host)
     {