use standard code style and var naming patterns for AppDiff

The standard pattern is to pass a Context in rather than call things like
getPackageManager in.  It should only pass a PackageManager if that is
actually being reused.

This shouldn't change the logic at all.

app/src/main/java/org/fdroid/fdroid/installer/Installer.java

@@ -106,15 +106,23 @@ public abstract class Installer {
         return intent;
     }
 
+    /**
+     * Return if this installation process has any new permissions that the user
+     * should be aware of.  Starting in {@code android-23}, all new permissions
+     * are requested when they are used, and the permissions prompt at time of
+     * install is not used.  All permissions in a new install are considered new.
+     *
+     * @return the number of new permissions
+     */
     private int newPermissionCount() {
         boolean supportsRuntimePermissions = apk.targetSdkVersion >= 23;
         if (supportsRuntimePermissions) {
             return 0;
         }
 
-        AppDiff appDiff = new AppDiff(context.getPackageManager(), apk);
+        AppDiff appDiff = new AppDiff(context, apk);
-        AppSecurityPermissions perms = new AppSecurityPermissions(context, appDiff.pkgInfo);
+        AppSecurityPermissions perms = new AppSecurityPermissions(context, appDiff.apkPackageInfo);
-        if (appDiff.installedAppInfo != null) {
+        if (appDiff.installedApplicationInfo != null) {
             // update to an existing app
             return perms.getPermissionCount(AppSecurityPermissions.WHICH_NEW);
         }

app/src/main/java/org/fdroid/fdroid/privileged/views/AppDiff.java

@@ -18,55 +18,51 @@
 
 package org.fdroid.fdroid.privileged.views;
 
+import android.content.Context;
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
-
 import org.fdroid.fdroid.data.Apk;
 
+/**
+ * Represents the permissions difference between the installed APK, and the
+ * update APK represented by {@link Apk}.
+ */
 public class AppDiff {
 
-    private final PackageManager pm;
+    public final PackageInfo apkPackageInfo;
-    public final PackageInfo pkgInfo;
+    public final ApplicationInfo installedApplicationInfo;
-    public ApplicationInfo installedAppInfo;
 
-    /**
+    public AppDiff(Context context, Apk apk) {
-     * Constructor based on F-Droids Apk object
+        PackageManager pm = context.getPackageManager();
-     */
+        apkPackageInfo = new PackageInfo();
-    public AppDiff(PackageManager pm, Apk apk) {
+        apkPackageInfo.packageName = apk.packageName;
-        this.pm = pm;
+        apkPackageInfo.applicationInfo = new ApplicationInfo();
+        apkPackageInfo.requestedPermissions = apk.requestedPermissions;
 
-        pkgInfo = new PackageInfo();
+        String packageName = apkPackageInfo.packageName;
-        pkgInfo.packageName = apk.packageName;
-        pkgInfo.applicationInfo = new ApplicationInfo();
-        pkgInfo.requestedPermissions = apk.requestedPermissions;
-
-        init();
-    }
-
-    private void init() {
-        String pkgName = pkgInfo.packageName;
         // Check if there is already a package on the device with this name
         // but it has been renamed to something else.
-        final String[] oldName = pm.canonicalToCurrentPackageNames(new String[]{pkgName});
+        final String[] oldName = pm.canonicalToCurrentPackageNames(new String[]{packageName});
         if (oldName != null && oldName.length > 0 && oldName[0] != null) {
-            pkgName = oldName[0];
+            packageName = oldName[0];
-            pkgInfo.packageName = pkgName;
+            apkPackageInfo.packageName = packageName;
-            pkgInfo.applicationInfo.packageName = pkgName;
+            apkPackageInfo.applicationInfo.packageName = packageName;
         }
         // Check if package is already installed
+        ApplicationInfo applicationInfo;
         try {
             // This is a little convoluted because we want to get all uninstalled
             // apps, but this may include apps with just data, and if it is just
             // data we still want to count it as "installed".
             //noinspection WrongConstant (lint is actually wrong here!)
-            installedAppInfo = pm.getApplicationInfo(pkgName,
+            applicationInfo = pm.getApplicationInfo(packageName, PackageManager.GET_UNINSTALLED_PACKAGES);
-                    PackageManager.GET_UNINSTALLED_PACKAGES);
+            if ((applicationInfo.flags & ApplicationInfo.FLAG_INSTALLED) == 0) {
-            if ((installedAppInfo.flags & ApplicationInfo.FLAG_INSTALLED) == 0) {
+                applicationInfo = null;
-                installedAppInfo = null;
             }
         } catch (PackageManager.NameNotFoundException e) {
-            installedAppInfo = null;
+            applicationInfo = null;
         }
+        installedApplicationInfo = applicationInfo;
     }
 }

app/src/main/java/org/fdroid/fdroid/privileged/views/InstallConfirmActivity.java

@@ -92,9 +92,9 @@ public class InstallConfirmActivity extends FragmentActivity implements OnCancel
         scrollView = null;
         okCanInstall = false;
         int msg = 0;
-        AppSecurityPermissions perms = new AppSecurityPermissions(this, appDiff.pkgInfo);
+        AppSecurityPermissions perms = new AppSecurityPermissions(this, appDiff.apkPackageInfo);
-        if (appDiff.installedAppInfo != null) {
+        if (appDiff.installedApplicationInfo != null) {
-            msg = (appDiff.installedAppInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0
+            msg = (appDiff.installedApplicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0
                     ? R.string.install_confirm_update_system
                     : R.string.install_confirm_update;
             scrollView = new CaffeinatedScrollView(this);
@@ -131,10 +131,10 @@ public class InstallConfirmActivity extends FragmentActivity implements OnCancel
         }
 
         if (!permVisible) {
-            if (appDiff.installedAppInfo != null) {
+            if (appDiff.installedApplicationInfo != null) {
                 // This is an update to an application, but there are no
                 // permissions at all.
-                msg = (appDiff.installedAppInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0
+                msg = (appDiff.installedApplicationInfo.flags & ApplicationInfo.FLAG_SYSTEM) != 0
                         ? R.string.install_confirm_update_system_no_perms
                         : R.string.install_confirm_update_no_perms;
             } else {
@@ -182,7 +182,7 @@ public class InstallConfirmActivity extends FragmentActivity implements OnCancel
         app = AppProvider.Helper.findSpecificApp(getContentResolver(),
                 apk.packageName, apk.repoId, Schema.AppMetadataTable.Cols.ALL);
 
-        appDiff = new AppDiff(getPackageManager(), apk);
+        appDiff = new AppDiff(this, apk);
 
         setContentView(R.layout.install_start);
 

app/src/main/java/org/fdroid/fdroid/views/AppDetailsRecyclerViewAdapter.java

@@ -789,8 +789,8 @@ public class AppDetailsRecyclerViewAdapter
             headerView.setText(R.string.permissions);
             updateExpandableItem(false);
             contentView.removeAllViews();
-            AppDiff appDiff = new AppDiff(context.getPackageManager(), versions.get(0));
+            AppDiff appDiff = new AppDiff(context, versions.get(0));
-            AppSecurityPermissions perms = new AppSecurityPermissions(context, appDiff.pkgInfo);
+            AppSecurityPermissions perms = new AppSecurityPermissions(context, appDiff.apkPackageInfo);
             contentView.addView(perms.getPermissionsView(AppSecurityPermissions.WHICH_ALL));
         }