Android: VNCConn: add UTF-8 cuttext sending

Closes #252

Author: bk138

android/app/src/main/cpp/vncconn.c

@@ -695,6 +695,20 @@ JNIEXPORT jboolean JNICALL Java_com_coboltforge_dontmind_multivnc_VNCConn_rfbSen
         return JNI_FALSE;
 }
 
+JNIEXPORT jboolean JNICALL Java_com_coboltforge_dontmind_multivnc_VNCConn_rfbSendClientCutTextUTF8(JNIEnv *env, jobject obj, jstring jText) {
+    rfbClient *cl = getRfbClient(env, obj);
+    if (cl) {
+        const char *cText = (*env)->GetStringUTFChars(env, jText, NULL);
+        if (!cText)
+            return JNI_FALSE;
+        jboolean status = SendClientCutTextUTF8(cl, (char *) cText, (int) strlen(cText));
+        (*env)->ReleaseStringUTFChars(env, jText, cText);
+        return status;
+    }
+    else
+        return JNI_FALSE;
+}
+
 JNIEXPORT jboolean JNICALL Java_com_coboltforge_dontmind_multivnc_VNCConn_rfbIsEncrypted(JNIEnv *env, jobject obj) {
     rfbClient *cl = getRfbClient(env, obj);
     if (cl)

android/app/src/main/java/com/coboltforge/dontmind/multivnc/VNCConn.java

@@ -376,11 +376,21 @@ private boolean sendKeyEvent(OutputEvent.KeyboardEvent evt) {
 
 
 		private boolean sendCutText(String text) {
+			boolean status = false;
 			if (rfbClient != 0) {
-				if (Utils.DEBUG()) Log.d(TAG, "sending cuttext " + text);
-				return rfbSendClientCutText(StandardCharsets.ISO_8859_1.encode(text).array());
+				// first, try sending UTF-8
+				if(rfbSendClientCutTextUTF8(text)) {
+					if (Utils.DEBUG()) Log.d(TAG, "Sent UTF-8 cuttext: '"  + text + "' successfully");
+					status = true;
+				} else {
+					// server does not support Extended Clipboard, try Latin-1.
+					// encode() docs say: "This method always replaces malformed-input and unmappable-character
+					// sequences with this charset's default replacement string."
+					status = rfbSendClientCutText(StandardCharsets.ISO_8859_1.encode(text).array());
+					if (Utils.DEBUG()) Log.d(TAG, "Sent ISO-8859-1 cuttext: '"  + text + "'" + (status ? "successfully" : "unsuccessfully"));
+				}
 			}
-			return false;
+			return status;
 		}
 
 
@@ -404,6 +414,7 @@ private native boolean rfbInit(String host, int port, int repeaterId, int bytesP
 	private native boolean rfbSendKeyEvent(long keysym, boolean down);
 	private native boolean rfbSendPointerEvent(int x, int y, int buttonMask);
 	private native boolean rfbSendClientCutText(byte[] bytes);
+	private native boolean rfbSendClientCutTextUTF8(String text);
 	private native boolean rfbIsEncrypted();