Chrome-side patch for IsAppInstalled.

content/public/android/java/src/org/chromium/content/browser/installedapp/InstalledAppProviderImpl.java

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.content.browser.installedapp;
+
+import android.content.Context;
+import android.content.pm.PackageManager;
+import android.content.pm.PackageManager.NameNotFoundException;
+import android.content.res.Resources;
+
+import org.chromium.mojo.system.MojoException;
+import org.chromium.mojom.content.InstalledAppProvider;
+import org.chromium.mojom.content.RelatedApplication;
+
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.net.MalformedURLException;
+import java.net.URL;
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+/**
+ * Android implementation of the InstalledAppProvider service defined in
+ * content/common/installedapp/installed_app_provider.mojom.
+ */
+public class InstalledAppProviderImpl implements InstalledAppProvider {
+    private Context mContext;
+    private static final String ASSET_DESCRIPTOR_FIELD_TARGET = "target";
+    private static final String ASSET_DESCRIPTOR_WEB = "web";
+    private static final String ASSET_DESCRIPTOR_FIELD_SITE = "site";
+    private static final String ASSET_DESCRIPTOR_FIELD_NAMESPACE = "namespace";
+    private static final String ASSOCIATED_ASSETS_KEY = "associated_assets";
+    private static final String RELATED_APP_ANDROID_PLATFORM = "play";
+
+    public InstalledAppProviderImpl(Context context) {
+        mContext = context;
+    }
+
+    @Override
+    public void filterInstalledApps(
+            RelatedApplication[] apps, String origin, FilterInstalledAppsResponse callback) {
+        callback.call(filterAndroidInstalledApps(apps, origin));
+    }
+
+    public RelatedApplication[] filterAndroidInstalledApps(
+            RelatedApplication[] apps, String origin) {
+        ArrayList<RelatedApplication> installedApps = new ArrayList<RelatedApplication>();
+        PackageManager pm = mContext.getPackageManager();
+        for (RelatedApplication app : apps) {
+            // If the package is of type "play" and origin is associated with package,
+            // add the package to the list of valid packages.
+            if (app.platform.equals(RELATED_APP_ANDROID_PLATFORM)
+                    && isOriginAssociatedWithPackage(app.id, origin, pm)) {
+                installedApps.add(app);
+            }
+        }
+        RelatedApplication installedAppsArray[] = new RelatedApplication[installedApps.size()];
+        installedAppsArray = installedApps.toArray(installedAppsArray);
+        return installedAppsArray;
+    }
+
+    @Override
+    public void close() {}
+
+    @Override
+    public void onConnectionError(MojoException e) {}
+
+    private static List<String> getAssociations(String packageName, PackageManager pm) {
+        Resources resources;
+
+        try {
+            resources = pm.getResourcesForApplication(packageName);
+        } catch (NameNotFoundException e) {
+            return Collections.<String>emptyList();
+        }
+
+        if (resources == null) {
+            return Collections.<String>emptyList();
+        }
+
+        int identifier = resources.getIdentifier(ASSOCIATED_ASSETS_KEY, "array", packageName);
+        if (identifier == 0) {
+            return Collections.<String>emptyList();
+        }
+        return Arrays.asList(resources.getStringArray(identifier));
+    }
+
+    private static boolean isOriginAssociatedWithPackage(
+            String packageName, String origin, PackageManager pm) {
+        List<String> associations = getAssociations(packageName, pm);
+        URL originURL;
+        try {
+            originURL = new URL(origin);
+        } catch (MalformedURLException e) {
+            return false;
+        }
+
+        for (String statementString : associations) {
+            try {
+                JSONObject statement = new JSONObject(statementString);
+                String assetDescriptorJson = statement.getString(ASSET_DESCRIPTOR_FIELD_TARGET);
+                JSONObject assetJson = new JSONObject(assetDescriptorJson);
+
+                // If it is not a web appet, skip it.
+                if (!isAssetIsWeb(assetJson)) {
+                    continue;
+                }
+
+                URL assetURL;
+                try {
+                    assetURL = new URL(assetJson.getString(ASSET_DESCRIPTOR_FIELD_SITE));
+                } catch (MalformedURLException e) {
+                    continue;
+                }
+
+                // The URL is considered equivalent if the scheme, host, and port match, according
+                // to the DigitalAssetLinks v1 spec.
+                if (statementTargetMatches(originURL, assetURL)) {
+                    return true;
+                }
+            } catch (JSONException e) {
+                continue;
+            }
+        }
+
+        return false;
+    }
+
+    private static boolean isAssetIsWeb(JSONObject asset) {
+        try {
+            return asset.getString(ASSET_DESCRIPTOR_FIELD_NAMESPACE).equals(ASSET_DESCRIPTOR_WEB);
+        } catch (JSONException e) {
+            return false;
+        }
+    }
+
+    private static boolean statementTargetMatches(URL originURL, URL assetURL) {
+        return (assetURL.getProtocol().equals(originURL.getProtocol())
+                && assetURL.getHost().equals(originURL.getHost())
+                && assetURL.getPort() == originURL.getPort());
+    }
+}