增加可以 alert

README.md

+參考資料：
+# https://stackoverflow.com/questions/8648616/webview-javascript-cross-domain-from-a-local-html-file
+# 為了讓 alert 可以生效 https://issuetracker.google.com/issues/36905249
+

app/src/main/AndroidManifest.xml

@@ -2,6 +2,8 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="pdfjs.scott.idv.androidpdfjs">
 
+    <uses-permission android:name="android.permission.INTERNET"/>
+
     <application
         android:allowBackup="true"
         android:icon="@mipmap/ic_launcher"

app/src/main/assets/index.html

@@ -51,6 +51,8 @@
         PDFJS.getDocument(url).then((pdf) => {
             pdfDoc = pdf;
             renderPage(1);
+        }).catch((error) => {
+            alert(error);
         });
     </script>
 </head>

app/src/main/java/pdfjs/scott/idv/androidpdfjs/MainActivity.java

@@ -3,6 +3,7 @@ package pdfjs.scott.idv.androidpdfjs;
 import android.annotation.SuppressLint;
 import android.support.v7.app.AppCompatActivity;
 import android.os.Bundle;
+import android.webkit.WebChromeClient;
 import android.webkit.WebSettings;
 import android.webkit.WebView;
 
@@ -17,12 +18,17 @@ public class MainActivity extends AppCompatActivity {
         initView();
 
         String pdfUrl = "file:///android_asset/pdf-js-demo.pdf";
+        // pdfUrl = "http://10.57.104.139/IBM-0308.pdf";
+
         mWebView.loadUrl("file:///android_asset/index.html?" + pdfUrl);
     }
 
     @SuppressLint("SetJavaScriptEnabled")
     private void initView() {
         mWebView = findViewById(R.id.webView);
+        // 為了讓 alert 可以生效
+        // https://issuetracker.google.com/issues/36905249
+        mWebView.setWebChromeClient(new WebChromeClient());
 
         WebSettings webSettings = mWebView.getSettings();
         webSettings.setJavaScriptEnabled(true);