Implement new functions for the WebView component (#2043)

appinventor/appengine/src/com/google/appinventor/client/youngandroid/YoungAndroidFormUpgrader.java

@@ -1611,7 +1611,7 @@ public final class YoungAndroidFormUpgrader {
 
   private static int upgradeWebViewerProperties(Map<String, JSONValue> componentProperties,
                                                 int srcCompVersion) {
-    if (srcCompVersion < 8) {
+    if (srcCompVersion < 9) {
       // The CanGoForward and CanGoBack methods were added.
       // No properties need to be modified to upgrade to version 2.
       // UsesLocation property added.
@@ -1622,7 +1622,8 @@ public final class YoungAndroidFormUpgrader {
       // ClearCaches method was added (version 6)
       // WebViewStringChange event was added (version 7)
       // PageLoaded event was added (version 8)
-      srcCompVersion = 8;
+      // BeforePageLoad event and Stop, Reload, and ClearCookies methods added (version 9)
+      srcCompVersion = 9;
     }
     return srcCompVersion;
   }

appinventor/blocklyeditor/src/versioning.js

@@ -2676,7 +2676,10 @@ Blockly.Versioning.AllUpgradeMaps =
     7: "noUpgrade",
 
     //AI2: Added PageLoaded
-    8: "noUpgrade"
+    8: "noUpgrade",
+      
+    // AI2: Added BeforePageLoad event and Stop, Reload, and ClearCookies methods
+    9: "noUpgrade"
 
   }, // End WebViewer upgraders
 

appinventor/components/src/com/google/appinventor/components/common/YaVersion.java

@@ -501,8 +501,10 @@ public class YaVersion {
   // - CANVAS_COMPONENT_VERSION was incremented to 13
   // For YOUNG_ANDROID_VERSION 202:
   // - BLOCKS_LANGUAGE_VERSION was incremented to 30
+  // For YOUNG_ANDROID_VERSION 203:
+  // - WEBVIEWER_COMPONENT_VERSION was incremented to 9
 
-  public static final int YOUNG_ANDROID_VERSION = 202;
+  public static final int YOUNG_ANDROID_VERSION = 203;
 
   // ............................... Blocks Language Version Number ...............................
 
@@ -1305,7 +1307,10 @@ public class YaVersion {
   // - Added WebViewStringChange event
   //For WEBVIEWER_COMPONENT_VERSION 8:
   // - Added PageLoaded event
-  public static final int WEBVIEWER_COMPONENT_VERSION = 8;
+  // For WEBVIEWER_COMPONENT_VERSION 9:
+  // - Added BeforePageLoad event
+  // - Added Stop, Reload, and ClearCookies methods
+  public static final int WEBVIEWER_COMPONENT_VERSION = 9;
 
   // For MEDIASTORE_COMPONENT_VERSION 1:
   // - Initial Version.

appinventor/components/src/com/google/appinventor/components/runtime/WebViewer.java

@@ -26,8 +26,10 @@ import com.google.appinventor.components.runtime.util.FroyoUtil;
 import com.google.appinventor.components.runtime.util.MediaUtil;
 import com.google.appinventor.components.runtime.util.SdkLevel;
 
+import android.graphics.Bitmap;
 import android.view.MotionEvent;
 import android.view.View;
+import android.webkit.CookieManager;
 import android.webkit.WebView;
 import android.webkit.WebViewClient;
 
@@ -211,6 +213,11 @@ public final class WebViewer extends AndroidViewComponent {
       return !followLinks;
     }
 
+    @Override
+    public void onPageStarted(WebView view, String url, Bitmap favicon) {
+      BeforePageLoad(url);
+    }
+
     @Override
     public void onPageFinished(WebView view, String url) {
       PageLoaded(url);
@@ -421,6 +428,24 @@ public final class WebViewer extends AndroidViewComponent {
     loadUrl("GoToUrl", url);
   }
 
+  /**
+   * Stop loading a page.
+   */
+  @SimpleFunction(
+      description = "Stop loading a page.")
+  public void StopLoading() {
+    webview.stopLoading();
+  }
+
+  /**
+   * Reload the current page.
+   */
+  @SimpleFunction(
+      description = "Reload the current page.")
+  public void Reload() {
+    webview.reload();
+  }
+
   /**
    * Specifies whether or not this `WebViewer` can access the JavaScript
    * geolocation API.
@@ -498,6 +523,20 @@ public final class WebViewer extends AndroidViewComponent {
     webview.clearCache(true);
   }
 
+   /**
+   * Clear the webview's cookies. This is useful if you want to
+   * sign the user out of a website that uses them to store logins.
+   */
+  @SimpleFunction(description = "Clear WebView cookies.")
+  public void ClearCookies() {
+    CookieManager cookieManager = CookieManager.getInstance();
+    if (SdkLevel.getLevel() >= SdkLevel.LEVEL_LOLLIPOP) {
+      cookieManager.removeAllCookies(null);
+    } else {
+      cookieManager.removeAllCookie();
+    }
+  }
+
   /**
    * Event that runs when the `AppInventor.setWebViewString` method is called from JavaScript.
    * The new {@link #WebViewString()} is given by the `value`{:.variable.block} parameter.
@@ -508,6 +547,11 @@ public final class WebViewer extends AndroidViewComponent {
     EventDispatcher.dispatchEvent(this, "WebViewStringChange", value);
   }
 
+  @SimpleEvent(description = "When a page is about to load this event is run.")
+  public void BeforePageLoad(String url) {
+    EventDispatcher.dispatchEvent(this, "BeforePageLoad", url);
+  }
+
   @SimpleEvent(description = "When a page is finished loading this event is run.")
   public void PageLoaded(String url) {
     EventDispatcher.dispatchEvent(this, "PageLoaded", url);

appinventor/components/src/com/google/appinventor/components/runtime/util/FroyoUtil.java

@@ -8,6 +8,7 @@ package com.google.appinventor.components.runtime.util;
 
 import android.app.Activity;
 import android.content.Context;
+import android.graphics.Bitmap;
 import android.media.AudioManager;
 import android.net.http.SslError;
 import android.view.Display;
@@ -143,10 +144,14 @@ public class FroyoUtil {
         }
       }
 
+      @Override
+      public void onPageStarted(WebView view, String url, Bitmap favicon) {
+        EventDispatcher.dispatchEvent(component, "BeforePageLoad", url);
+      }
+
       @Override
       public void onPageFinished(WebView view, String url) {
         EventDispatcher.dispatchEvent(component, "PageLoaded", url);
-
       }
     };
   }

appinventor/docs/html/reference/components/userinterface.html

@@ -1495,6 +1495,8 @@ having dark grey components.</li>
 <h3 id="WebViewer-Events">Events</h3>
 
 <dl class="events">
+  <dt id="WebViewer.BeforePageLoad">BeforePageLoad(<em class="text">url</em>)</dt>
+  <dd>When a page is about to load this event is run.</dd>
   <dt id="WebViewer.PageLoaded">PageLoaded(<em class="text">url</em>)</dt>
   <dd>When a page is finished loading this event is run.</dd>
   <dt id="WebViewer.WebViewStringChange">WebViewStringChange(<em class="text">value</em>)</dt>
@@ -1513,6 +1515,9 @@ having dark grey components.</li>
   <dd>Clear the internal webview cache, both ram and disk. This is useful
  when using the <code class="highlighter-rouge">WebViewer</code> to poll a page that may not be sending
  appropriate cache control headers.</dd>
+  <dt id="WebViewer.ClearCookies" class="method"><i></i> ClearCookies()</dt>
+  <dd>Clear the webview’s cookies. This is useful if you want to
+ sign the user out of a website that uses them to store logins.</dd>
   <dt id="WebViewer.ClearLocations" class="method"><i></i> ClearLocations()</dt>
   <dd>Clear Stored Location permissions. When the geolocation API is used in
  the <code class="highlighter-rouge">WebViewer</code>, the end user is prompted on a per URL basis for whether
@@ -1531,6 +1536,10 @@ Eclair, this function is a no-op on older phones.</p>
  home URL is changed.</dd>
   <dt id="WebViewer.GoToUrl" class="method"><i></i> GoToUrl(<em class="text">url</em>)</dt>
   <dd>Load the page at the given URL.</dd>
+  <dt id="WebViewer.Reload" class="method"><i></i> Reload()</dt>
+  <dd>Reload the current page.</dd>
+  <dt id="WebViewer.StopLoading" class="method"><i></i> StopLoading()</dt>
+  <dd>Stop loading a page.</dd>
 </dl>
 
 </article>

appinventor/docs/markdown/reference/components/userinterface.md

@@ -1702,6 +1702,9 @@ Component for viewing Web pages.
 
 {:.events}
 
+{:id="WebViewer.BeforePageLoad"} BeforePageLoad(*url*{:.text})
+: When a page is about to load this event is run.
+
 {:id="WebViewer.PageLoaded"} PageLoaded(*url*{:.text})
 : When a page is finished loading this event is run.
 
@@ -1724,6 +1727,10 @@ Component for viewing Web pages.
  when using the `WebViewer` to poll a page that may not be sending
  appropriate cache control headers.
 
+{:id="WebViewer.ClearCookies" class="method"} <i/> ClearCookies()
+: Clear the webview's cookies. This is useful if you want to
+ sign the user out of a website that uses them to store logins.
+
 {:id="WebViewer.ClearLocations" class="method"} <i/> ClearLocations()
 : Clear Stored Location permissions. When the geolocation API is used in
  the `WebViewer`, the end user is prompted on a per URL basis for whether
@@ -1745,3 +1752,9 @@ Component for viewing Web pages.
 
 {:id="WebViewer.GoToUrl" class="method"} <i/> GoToUrl(*url*{:.text})
 : Load the page at the given URL.
+
+{:id="WebViewer.Reload" class="method"} <i/> Reload()
+: Reload the current page.
+
+{:id="WebViewer.StopLoading" class="method"} <i/> StopLoading()
+: Stop loading a page.