android: Fix crash when setting window title on wrong thread

makepanda/makepanda.py

@@ -4946,12 +4946,14 @@ if GetTarget() == 'android':
     TargetAdd('org/panda3d/android/NativeOStream.class', opts=OPTS, input='NativeOStream.java')
     TargetAdd('org/panda3d/android/PandaActivity.class', opts=OPTS, input='PandaActivity.java')
     TargetAdd('org/panda3d/android/PandaActivity$1.class', opts=OPTS+['DEPENDENCYONLY'], input='PandaActivity.java')
+    TargetAdd('org/panda3d/android/PandaActivity$2.class', opts=OPTS+['DEPENDENCYONLY'], input='PandaActivity.java')
     TargetAdd('org/panda3d/android/PythonActivity.class', opts=OPTS, input='PythonActivity.java')
 
     TargetAdd('classes.dex', input='org/panda3d/android/NativeIStream.class')
     TargetAdd('classes.dex', input='org/panda3d/android/NativeOStream.class')
     TargetAdd('classes.dex', input='org/panda3d/android/PandaActivity.class')
     TargetAdd('classes.dex', input='org/panda3d/android/PandaActivity$1.class')
+    TargetAdd('classes.dex', input='org/panda3d/android/PandaActivity$2.class')
     TargetAdd('classes.dex', input='org/panda3d/android/PythonActivity.class')
 
     TargetAdd('p3android_composite1.obj', opts=OPTS, input='p3android_composite1.cxx')

panda/src/android/PandaActivity.java

@@ -159,6 +159,18 @@ public class PandaActivity extends NativeActivity {
         return getCacheDir().toString();
     }
 
+    /**
+     * Sets the window title.
+     */
+    public void setWindowTitle(final CharSequence title) {
+        final PandaActivity activity = this;
+        runOnUiThread(new Runnable() {
+            public void run() {
+                activity.setTitle(title);
+            }
+        });
+    }
+
     /**
      * Shows a pop-up notification.
      */

panda/src/android/config_android.cxx

@@ -27,11 +27,9 @@ jmethodID jni_PandaActivity_readBitmap;
 jmethodID jni_PandaActivity_createBitmap;
 jmethodID jni_PandaActivity_compressBitmap;
 jmethodID jni_PandaActivity_showToast;
+jmethodID jni_PandaActivity_setWindowTitle;
 jmethodID jni_PandaActivity_findLibrary;
 
-jclass    jni_Activity;
-jmethodID jni_Activity_setTitle;
-
 jclass   jni_BitmapFactory_Options;
 jfieldID jni_BitmapFactory_Options_outWidth;
 jfieldID jni_BitmapFactory_Options_outHeight;
@@ -81,17 +79,15 @@ jint JNI_OnLoad(JavaVM *jvm, void *reserved) {
   jni_PandaActivity_compressBitmap = env->GetStaticMethodID(jni_PandaActivity,
                    "compressBitmap", "(Landroid/graphics/Bitmap;IIJ)Z");
 
+  jni_PandaActivity_setWindowTitle = env->GetMethodID(jni_PandaActivity,
+                   "setWindowTitle", "(Ljava/lang/CharSequence;)V");
+
   jni_PandaActivity_showToast = env->GetMethodID(jni_PandaActivity,
                    "showToast", "(Ljava/lang/String;I)V");
 
   jni_PandaActivity_findLibrary = env->GetMethodID(jni_PandaActivity,
                    "findLibrary", "(Ljava/lang/String;)Ljava/lang/String;");
 
-  jni_Activity = env->FindClass("android/app/Activity");
-  jni_Activity = (jclass) env->NewGlobalRef(jni_Activity);
-  jni_Activity_setTitle = env->GetMethodID(jni_Activity,
-              "setTitle", "(Ljava/lang/CharSequence;)V");
-
   jni_BitmapFactory_Options = env->FindClass("android/graphics/BitmapFactory$Options");
   jni_BitmapFactory_Options = (jclass) env->NewGlobalRef(jni_BitmapFactory_Options);
 
@@ -130,7 +126,6 @@ void JNI_OnUnload(JavaVM *jvm, void *reserved) {
   nassertv(env != nullptr);
 
   env->DeleteGlobalRef(jni_PandaActivity);
-  env->DeleteGlobalRef(jni_Activity);
   env->DeleteGlobalRef(jni_BitmapFactory_Options);
 
   // These will no longer work without JNI, so unregister them.
@@ -174,14 +169,14 @@ Filename android_find_library(ANativeActivity *activity, const std::string &lib)
  * Sets the window title of the activity.
  */
 void android_set_title(ANativeActivity *activity, const std::string &title) {
-  nassertv(jni_Activity_setTitle);
+  nassertv(jni_PandaActivity_setWindowTitle);
 
   Thread *thread = Thread::get_current_thread();
   JNIEnv *env = thread->get_jni_env();
   nassertv(env != nullptr);
 
   jstring jmsg = env->NewStringUTF(title.c_str());
-  env->CallVoidMethod(activity->clazz, jni_Activity_setTitle, jmsg);
+  env->CallVoidMethod(activity->clazz, jni_PandaActivity_setWindowTitle, jmsg);
   env->DeleteLocalRef(jmsg);
 }
 

panda/src/android/config_android.h

@@ -33,11 +33,9 @@ extern jmethodID jni_PandaActivity_readBitmapHeader;
 extern jmethodID jni_PandaActivity_readBitmap;
 extern jmethodID jni_PandaActivity_createBitmap;
 extern jmethodID jni_PandaActivity_compressBitmap;
+extern jmethodID jni_PandaActivity_setWindowTitle;
 extern jmethodID jni_PandaActivity_showToast;
 
-extern jclass    jni_Activity;
-extern jmethodID jni_Activity_setTitle;
-
 extern jclass   jni_BitmapFactory_Options;
 extern jfieldID jni_BitmapFactory_Options_outWidth;
 extern jfieldID jni_BitmapFactory_Options_outHeight;