Add K9WebViewClient to open links in (external) browser

src/com/fsck/k9/view/K9WebViewClient.java

@@ -0,0 +1,52 @@
+package com.fsck.k9.view;
+
+
+import android.content.ActivityNotFoundException;
+import android.content.Context;
+import android.content.Intent;
+import android.net.Uri;
+import android.provider.Browser;
+import android.webkit.WebView;
+import android.webkit.WebViewClient;
+
+
+public class K9WebViewClient extends WebViewClient {
+    public static WebViewClient newInstance() {
+        return new K9WebViewClient();
+    }
+
+
+    private K9WebViewClient() {}
+
+    @Override
+    public boolean shouldOverrideUrlLoading(WebView webView, String url) {
+        Uri uri = Uri.parse(url);
+
+        Context context = webView.getContext();
+        Intent intent = createBrowserViewIntent(uri, context);
+        addActivityFlags(intent);
+
+        boolean overridingUrlLoading = false;
+        try {
+            context.startActivity(intent);
+            overridingUrlLoading = true;
+        } catch (ActivityNotFoundException ex) {
+            // If no application can handle the URL, assume that the WebView can handle it.
+        }
+
+        return overridingUrlLoading;
+    }
+
+    private Intent createBrowserViewIntent(Uri uri, Context context) {
+        Intent intent = new Intent(Intent.ACTION_VIEW, uri);
+        intent.addCategory(Intent.CATEGORY_BROWSABLE);
+        intent.putExtra(Browser.EXTRA_APPLICATION_ID, context.getPackageName());
+        intent.putExtra(Browser.EXTRA_CREATE_NEW_TAB, true);
+        return intent;
+    }
+
+    protected void addActivityFlags(Intent intent) {
+        intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_WHEN_TASK_RESET);
+    }
+}
+

src/com/fsck/k9/view/MessageWebView.java

@@ -87,6 +87,8 @@ public class MessageWebView extends RigidWebView {
 
         // Disable network images by default.  This is overridden by preferences.
         blockNetworkData(true);
+
+        setWebViewClient(K9WebViewClient.newInstance());
     }
 
     /**