TIMOB-5824-2_1_X: Android: WebView.evalJS Causes Form Input Fields to Lost/Not Retain Focus

android/modules/ui/src/java/ti/modules/titanium/ui/WebViewProxy.java

@@ -311,26 +311,18 @@ public void release()
 
 	@Override
 	public void onStart(Activity activity) {
-		// TODO Auto-generated method stub
-
 	}
 
 	@Override
 	public void onResume(Activity activity) {
-		// TODO Auto-generated method stub
-
 	}
 
 	@Override
 	public void onPause(Activity activity) {
-		// TODO Auto-generated method stub
-
 	}
 
 	@Override
 	public void onStop(Activity activity) {
-		// TODO Auto-generated method stub
-
 	}
 
 	@Override
@@ -340,6 +332,11 @@ public void onDestroy(Activity activity) {
 			return;
 		}
 
+		// We allow JS polling to continue until we exit the app. If we want to stop the polling when the app is
+		// backgrounded, we would need to move this to onStop(), and add the appropriate logic in onResume() to restart
+		// the polling.
+		webView.destroyWebViewBinding();
+
 		WebView nativeWebView = webView.getWebView();
 		if (nativeWebView == null) {
 			return;
@@ -348,6 +345,5 @@ public void onDestroy(Activity activity) {
 		nativeWebView.stopLoading();
 		super.releaseViews();
 	}
-
 
 }

android/modules/ui/src/java/ti/modules/titanium/ui/widget/webview/TiUIWebView.java

@@ -337,7 +337,6 @@ public void setUrl(String url)
 			getWebView().getSettings().setLoadWithOverviewMode(true);
 		}
 		getWebView().loadUrl(finalUrl);
-
 	}
 
 	public void changeProxyUrl(String url)
@@ -465,6 +464,11 @@ public void setBasicAuthentication(String username, String password)
 		client.setBasicAuthentication(username, password);
 	}
 
+	public void destroyWebViewBinding()
+	{
+		client.getBinding().destroy();
+	}
+
 	public void setPluginState(int pluginState)
 	{
 		if (Build.VERSION.SDK_INT > Build.VERSION_CODES.ECLAIR_MR1) {

android/modules/ui/src/java/ti/modules/titanium/ui/widget/webview/TiWebViewBinding.java

@@ -1,6 +1,6 @@
 /**
  * Appcelerator Titanium Mobile
- * Copyright (c) 2009-2011 by Appcelerator, Inc. All Rights Reserved.
+ * Copyright (c) 2009-2012 by Appcelerator, Inc. All Rights Reserved.
  * Licensed under the terms of the Apache Public License
  * Please see the LICENSE included with this distribution for details.
  */
@@ -11,7 +11,9 @@
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.util.HashMap;
+import java.util.Stack;
 import java.util.concurrent.Semaphore;
+import java.util.concurrent.TimeUnit;
 
 import org.appcelerator.kroll.KrollDict;
 import org.appcelerator.kroll.KrollEventCallback;
@@ -35,9 +37,22 @@ public class TiWebViewBinding
 	// - minify binding.js to create binding.min.js
 	protected final static String SCRIPT_INJECTION_ID = "__ti_injection";
 	protected final static String INJECTION_CODE;
+
+	// This is based on polling.min.js. If you have to change anything...
+	// - change polling.js
+	// - minify polling.js to create polling.min.js
+	protected static String POLLING_CODE = "";
 	static {
 		StringBuilder jsonCode = readResourceFile("json2.js");
 		StringBuilder tiCode = readResourceFile("binding.min.js");
+		StringBuilder pollingCode = readResourceFile("polling.min.js");
+
+		if (pollingCode == null) {
+			Log.w(LCAT, "Unable to read polling code");
+		} else {
+			POLLING_CODE = pollingCode.toString();
+		}
+
 		StringBuilder allCode = new StringBuilder();
 		allCode.append("\n<script id=\"" + SCRIPT_INJECTION_ID + "\">\n");
 		if (jsonCode == null) {
@@ -59,13 +74,15 @@ public class TiWebViewBinding
 		allCode = null;
 	}
 
-	private WebView webView;
+	private Stack<String> codeSnippets;
+	private boolean destroyed;
+
 	private KrollLogging apiBinding;
 	private AppBinding appBinding;
 
 	public TiWebViewBinding(WebView webView)
 	{
-		this.webView = webView;
+		codeSnippets = new Stack<String>();
 
 		apiBinding = KrollLogging.getDefault();
 		appBinding = new AppBinding();
@@ -84,6 +101,10 @@ public void destroy()
 		// remove any event listener that have already been added to the Ti.APP through
 		// this web view instance
 		appBinding.clearEventListeners();
+
+		returnSemaphore.release();
+		codeSnippets.clear();
+		destroyed = true;
 	}
 
 	private static StringBuilder readResourceFile(String fileName)
@@ -111,25 +132,27 @@ private static StringBuilder readResourceFile(String fileName)
 		return code;
 	}
 
-	private void evalJS(String code)
-	{
-		webView.loadUrl("javascript:" + code);
-	}
-
 	private Semaphore returnSemaphore = new Semaphore(0);
 	private String returnValue;
 
-	public String getJSValue(String expression)
+	synchronized public String getJSValue(String expression)
 	{
-		String code = "javascript:_TiReturn.setValue((function(){try{return " + expression
-			+ "+\"\";}catch(ti_eval_err){return '';}})());";
-		Log.d(LCAT, "getJSValue:" + code);
-		webView.loadUrl(code);
-		try {
-			returnSemaphore.acquire();
-			return returnValue;
-		} catch (InterruptedException e) {
-			Log.e(LCAT, "Interrupted", e);
+		// Don't try to evaluate js code again if the binding has already been destroyed
+		if (!destroyed) {
+			String code = "_TiReturn.setValue((function(){try{return " + expression
+				+ "+\"\";}catch(ti_eval_err){return '';}})());";
+			Log.d(LCAT, "getJSValue:" + code);
+			synchronized (codeSnippets) {
+				codeSnippets.push(code);
+			}
+			try {
+				if (!returnSemaphore.tryAcquire(1000, TimeUnit.MILLISECONDS)) {
+					Log.w(LCAT, "Timeout waiting to evaluate JS");
+				}
+				return returnValue;
+			} catch (InterruptedException e) {
+				Log.e(LCAT, "Interrupted", e);
+			}
 		}
 		return null;
 	}
@@ -168,7 +191,9 @@ public void call(Object data)
 			}
 
 			String code = "Ti.executeListener(" + id + dataString + ");";
-			evalJS(code);
+			synchronized (codeSnippets) {
+				codeSnippets.push(code);
+			}
 		}
 	}
 
@@ -217,5 +242,18 @@ public void clearEventListeners()
 				removeEventListener(event, appListeners.get(event));
 			}
 		}
+
+		public String getJSCode()
+		{
+			if (destroyed) {
+				return null;
+			}
+
+			String code;
+			synchronized (codeSnippets) {
+				code = codeSnippets.empty() ? "" : codeSnippets.pop();
+			}
+			return code;
+		}
 	}
 }

android/modules/ui/src/java/ti/modules/titanium/ui/widget/webview/TiWebViewClient.java

@@ -46,6 +46,11 @@ public void onPageFinished(WebView view, String url)
 		KrollDict data = new KrollDict();
 		data.put("url", url);
 		webView.getProxy().fireEvent("load", data);
+		WebView nativeWebView = webView.getWebView();
+
+		if (nativeWebView != null) {
+			webView.getWebView().loadUrl("javascript:" + TiWebViewBinding.POLLING_CODE);
+		}
 	}
 
 	public TiWebViewBinding getBinding()

android/modules/ui/src/java/ti/modules/titanium/ui/widget/webview/binding.js

@@ -57,4 +57,5 @@ var Ti = {
 		}
 	}
 };
+
 var Titanium = Ti;

android/modules/ui/src/java/ti/modules/titanium/ui/widget/webview/polling.js

@@ -0,0 +1,10 @@
+function checkForJSCode() {
+	var code = TiApp.getJSCode();
+	if ( code != undefined) {
+		eval(code);
+	} else {
+		clearInterval(refreshIntervalId);
+	}
+}
+
+var refreshIntervalId = setInterval(checkForJSCode, 250);