feat(android): add openFile to utils (#6895)

* feat(android): add openFile to utils

* tests: move test_openFile() test to apps/ui-tests-app

Small changes to openFile() method

tns-core-modules/utils/utils.android.ts

@@ -1,10 +1,16 @@
 import {
-    write as traceWrite, categories as traceCategories, messageType as traceMessageType
+    write as traceWrite,
+    categories as traceCategories,
+    messageType as traceMessageType,
 } from "../trace";
 
 export * from "./utils-common";
 
 import { getNativeApplication, android as androidApp } from "../application";
+import { device } from "../platform";
+import { FileSystemAccess } from "../file-system/file-system-access";
+
+const MIN_URI_SHARE_RESTRICTED_APK_VERSION = 24;
 
 export module layout {
     let density: number;
@@ -224,3 +230,145 @@ export function openUrl(location: string): boolean {
     }
     return true;
 }
+
+/**
+ * Check whether external storage is read only
+ *
+ * @returns {boolean} whether the external storage is read only
+ */
+function isExternalStorageReadOnly(): boolean {
+    const extStorageState = android.os.Environment.getExternalStorageState();
+    if (android.os.Environment.MEDIA_MOUNTED_READ_ONLY === extStorageState) {
+        return true;
+    }
+    return false;
+}
+
+/**
+ * Checks whether external storage is available
+ *
+ * @returns {boolean} whether external storage is available
+ */
+function isExternalStorageAvailable(): boolean {
+    const extStorageState = android.os.Environment.getExternalStorageState();
+    if (android.os.Environment.MEDIA_MOUNTED === extStorageState) {
+        return true;
+    }
+    return false;
+}
+
+/**
+ * Detect the mimetype of a file at a given path
+ *
+ * @param {string} filePath
+ * @returns {string} mimetype
+ */
+function getMimeTypeNameFromExtension(filePath: string): string {
+    const mimeTypeMap = android.webkit.MimeTypeMap.getSingleton();
+    const extension = new FileSystemAccess()
+        .getFileExtension(filePath)
+        .replace(".", "")
+        .toLowerCase();
+
+    return mimeTypeMap.getMimeTypeFromExtension(extension);
+}
+
+/**
+ * Open a file
+ *
+ * @param {string} filePath
+ * @returns {boolean} whether opening the file succeeded or not
+ */
+export function openFile(filePath: string): boolean {
+    const context = ad.getApplicationContext();
+    try {
+        // Ensure external storage is available
+        if (!isExternalStorageAvailable()) {
+            traceWrite(
+                `
+External storage is unavailable (please check app permissions).
+Applications cannot access internal storage of other application on Android (see: https://developer.android.com/guide/topics/data/data-storage).
+`,
+                traceCategories.Error,
+                traceMessageType.error,
+            );
+
+            return false;
+        }
+
+        // Ensure external storage is available
+        if (isExternalStorageReadOnly()) {
+            traceWrite("External storage is read only", traceCategories.Error, traceMessageType.error);
+            return false;
+        }
+
+        // Determine file mimetype & start creating intent
+        const mimeType = getMimeTypeNameFromExtension(filePath);
+        const intent = new android.content.Intent(android.content.Intent.ACTION_VIEW);
+        const chooserIntent = android.content.Intent.createChooser(intent, "Open File...");
+
+        intent.addFlags(android.content.Intent.FLAG_ACTIVITY_NEW_TASK);
+        chooserIntent.addFlags(android.content.Intent.FLAG_ACTIVITY_NEW_TASK);
+
+        // Android SDK <28 only requires starting the chooser Intent straight forwardly
+        const sdkVersion = parseInt(device.sdkVersion, 10);
+        if (sdkVersion && sdkVersion < MIN_URI_SHARE_RESTRICTED_APK_VERSION) {
+            traceWrite(
+                `detected sdk version ${sdkVersion} (< ${MIN_URI_SHARE_RESTRICTED_APK_VERSION}), using simple openFile`,
+                traceCategories.Debug
+            );
+            intent.setDataAndType(android.net.Uri.fromFile(new java.io.File(filePath)), mimeType);
+            context.startActivity(chooserIntent);
+            return true;
+        }
+
+        traceWrite(
+            `detected sdk version ${sdkVersion} (>= ${MIN_URI_SHARE_RESTRICTED_APK_VERSION}), using URI openFile`,
+            traceCategories.Debug
+        );
+
+        // Android SDK 24+ introduced file system permissions changes that disallow
+        // exposing URIs between applications
+        //
+        // see: https://developer.android.com/reference/android/os/FileUriExposedException
+        // see: https://github.com/NativeScript/NativeScript/issues/5661#issuecomment-456405380
+        const providerName = `${context.getPackageName()}.provider`;
+        traceWrite(`fully-qualified provider name [${providerName}]`, traceCategories.Debug);
+
+        const apkURI = android.support.v4.content.FileProvider.getUriForFile(
+            context,
+            providerName,
+            new java.io.File(filePath),
+        );
+
+        // Set flags & URI as data type on the view action
+        intent.addFlags(android.content.Intent.FLAG_GRANT_READ_URI_PERMISSION);
+        chooserIntent.addFlags(android.content.Intent.FLAG_GRANT_READ_URI_PERMISSION);
+
+        // Finish intent setup
+        intent.setDataAndType(apkURI, mimeType);
+
+        context.startActivity(chooserIntent);
+
+        return true;
+    } catch (err) {
+        const msg = err.message ? `: ${err.message}` : "";
+        traceWrite(`Error in openFile${msg}`, traceCategories.Error, traceMessageType.error);
+
+        if (msg &&
+            msg.includes("Attempt to invoke virtual method") &&
+            msg.includes("android.content.pm.ProviderInfo.loadXmlMetaData") &&
+            msg.includes("on a null object reference")) {
+            // Alert user to possible fix
+            traceWrite(
+                `
+Please ensure you have your manifest correctly configured with the FileProvider.
+(see: https://developer.android.com/reference/android/support/v4/content/FileProvider#ProviderDefinition)
+`,
+                traceCategories.Error,
+            );
+        }
+
+        return false;
+    }
+}