Create/test method to set "not downloadable" flag based on policy

Change-Id: I08bec46d0c961bdc9530768f5198346338b3e2f3

emailcommon/src/com/android/emailcommon/provider/Policy.java

@@ -19,6 +19,7 @@ import com.android.emailcommon.utility.Utility;
 
 import android.app.admin.DevicePolicyManager;
 import android.content.ContentProviderOperation;
+import android.content.ContentResolver;
 import android.content.ContentUris;
 import android.content.ContentValues;
 import android.content.Context;
@@ -113,6 +114,12 @@ public final class Policy extends EmailContent implements EmailContent.PolicyCol
 
     public static final Policy NO_POLICY = new Policy();
 
+    private static final String[] ATTACHMENT_RESET_PROJECTION =
+        new String[] {EmailContent.RECORD_ID, AttachmentColumns.SIZE, AttachmentColumns.FLAGS};
+    private static final int ATTACHMENT_RESET_PROJECTION_ID = 0;
+    private static final int ATTACHMENT_RESET_PROJECTION_SIZE = 1;
+    private static final int ATTACHMENT_RESET_PROJECTION_FLAGS = 2;
+
     public Policy() {
         mBaseUri = CONTENT_URI;
         // By default, the password mode is "none"
@@ -208,6 +215,48 @@ public final class Policy extends EmailContent implements EmailContent.PolicyCol
         }
     }
 
+
+    /**
+     * Review all attachment records for this account, and reset the "don't allow download" flag
+     * as required by the account's new security policies
+     * @param context the caller's context
+     * @param account the account whose attachments need to be reviewed
+     * @param policy the new policy for this account
+     */
+    public static void setAttachmentFlagsForNewPolicy(Context context, Account account,
+            Policy policy) {
+        // A nasty bit of work; start with all attachments for a given account
+        ContentResolver resolver = context.getContentResolver();
+        Cursor c = resolver.query(Attachment.CONTENT_URI, ATTACHMENT_RESET_PROJECTION,
+                AttachmentColumns.ACCOUNT_KEY + "=?", new String[] {Long.toString(account.mId)},
+                null);
+        ContentValues cv = new ContentValues();
+        try {
+            // Get maximum allowed size (0 if we don't allow attachments at all)
+            int policyMax = policy.mDontAllowAttachments ? 0 : (policy.mMaxAttachmentSize > 0) ?
+                    policy.mMaxAttachmentSize : Integer.MAX_VALUE;
+            while (c.moveToNext()) {
+                int flags = c.getInt(ATTACHMENT_RESET_PROJECTION_FLAGS);
+                int size = c.getInt(ATTACHMENT_RESET_PROJECTION_SIZE);
+                boolean wasRestricted = (flags & Attachment.FLAG_POLICY_DISALLOWS_DOWNLOAD) != 0;
+                boolean isRestricted = size > policyMax;
+                if (isRestricted != wasRestricted) {
+                    if (isRestricted) {
+                        flags |= Attachment.FLAG_POLICY_DISALLOWS_DOWNLOAD;
+                    } else {
+                        flags &= ~Attachment.FLAG_POLICY_DISALLOWS_DOWNLOAD;
+                    }
+                    long id = c.getLong(ATTACHMENT_RESET_PROJECTION_ID);
+                    cv.put(AttachmentColumns.FLAGS, flags);
+                    resolver.update(ContentUris.withAppendedId(Attachment.CONTENT_URI, id),
+                            cv, null, null);
+                }
+            }
+        } finally {
+            c.close();
+        }
+    }
+
     /**
      * Normalize the Policy.  If the password mode is "none", zero out all password-related fields;
      * zero out complex characters for simple passwords.

tests/src/com/android/email/provider/PolicyTests.java

@@ -18,6 +18,10 @@ package com.android.email.provider;
 
 import com.android.emailcommon.provider.EmailContent;
 import com.android.emailcommon.provider.EmailContent.Account;
+import com.android.emailcommon.provider.EmailContent.Attachment;
+import com.android.emailcommon.provider.EmailContent.AttachmentColumns;
+import com.android.emailcommon.provider.EmailContent.Mailbox;
+import com.android.emailcommon.provider.EmailContent.Message;
 import com.android.emailcommon.provider.Policy;
 
 import android.content.Context;
@@ -25,6 +29,8 @@ import android.os.Parcel;
 import android.test.ProviderTestCase2;
 import android.test.suitebuilder.annotation.MediumTest;
 
+import java.util.ArrayList;
+
 /**
  * This is a series of unit tests for the Policy class
  *
@@ -35,6 +41,9 @@ import android.test.suitebuilder.annotation.MediumTest;
 @MediumTest
 public class PolicyTests extends ProviderTestCase2<EmailProvider> {
 
+    private static final String CANT_DOWNLOAD_SELECTION = "(" + AttachmentColumns.FLAGS + "&" +
+        Attachment.FLAG_POLICY_DISALLOWS_DOWNLOAD + ")!=0";
+
     private Context mMockContext;
 
     public PolicyTests() {
@@ -104,6 +113,78 @@ public class PolicyTests extends ProviderTestCase2<EmailProvider> {
         assertNull(account.mSecuritySyncKey);
     }
 
+    private Attachment setupSimpleAttachment(String name, long size, Account acct) {
+        Attachment att = ProviderTestUtils.setupAttachment(-1, name, size, false, mMockContext);
+        att.mAccountKey = acct.mId;
+        return att;
+    }
+    public void testSetAttachmentFlagsForNewPolicy() {
+        Account acct = ProviderTestUtils.setupAccount("acct1", true, mMockContext);
+        Policy policy1 = new Policy();
+        policy1.mDontAllowAttachments = true;
+        policy1.setAccountPolicy(mMockContext, acct, "0");
+        Mailbox box = ProviderTestUtils.setupMailbox("box1", acct.mId, true, mMockContext);
+        Message msg1 = ProviderTestUtils.setupMessage("message1", acct.mId, box.mId, false, false,
+                mMockContext);
+        ArrayList<Attachment> atts = new ArrayList<Attachment>();
+        Attachment att1 = setupSimpleAttachment("fileName1", 10001L, acct);
+        atts.add(att1);
+        Attachment att2 = setupSimpleAttachment("fileName2", 20001L, acct);
+        atts.add(att2);
+        msg1.mAttachments = atts;
+        msg1.save(mMockContext);
+        Message msg2 = ProviderTestUtils.setupMessage("message2", acct.mId, box.mId, false, false,
+                mMockContext);
+        atts.clear();
+        Attachment att3 = setupSimpleAttachment("fileName3", 70001L, acct);
+        atts.add(att3);
+        Attachment att4 = setupSimpleAttachment("fileName4", 5001L, acct);
+        atts.add(att4);
+        msg2.mAttachments = atts;
+        msg2.save(mMockContext);
+        // Make sure we've got our 4 attachments
+        assertEquals(4, EmailContent.count(mMockContext, Attachment.CONTENT_URI));
+        // All should be downloadable
+        assertEquals(0, EmailContent.count(mMockContext, Attachment.CONTENT_URI,
+                CANT_DOWNLOAD_SELECTION, null));
+        // Enforce our no-attachments policy
+        Policy.setAttachmentFlagsForNewPolicy(mMockContext, acct, policy1);
+        // None should be downloadable
+        assertEquals(4, EmailContent.count(mMockContext, Attachment.CONTENT_URI,
+                CANT_DOWNLOAD_SELECTION, null));
+
+        Policy policy2 = new Policy();
+        policy2.mMaxAttachmentSize = 20000;
+        // Switch to new policy that sets a limit, but otherwise allows attachments
+        Policy.setAttachmentFlagsForNewPolicy(mMockContext, acct, policy2);
+        // Two shouldn't be downloadable
+        assertEquals(2, EmailContent.count(mMockContext, Attachment.CONTENT_URI,
+                CANT_DOWNLOAD_SELECTION, null));
+        // Make sure they're the right ones (att2 and att3)
+        att2 = Attachment.restoreAttachmentWithId(mMockContext, att2.mId);
+        assertTrue((att2.mFlags & Attachment.FLAG_POLICY_DISALLOWS_DOWNLOAD) != 0);
+        att3 = Attachment.restoreAttachmentWithId(mMockContext, att3.mId);
+        assertTrue((att3.mFlags & Attachment.FLAG_POLICY_DISALLOWS_DOWNLOAD) != 0);
+
+        Policy policy3 = new Policy();
+        policy3.mMaxAttachmentSize = 5001;
+        // Switch to new policy that sets a lower limit
+        Policy.setAttachmentFlagsForNewPolicy(mMockContext, acct, policy3);
+        // Three shouldn't be downloadable
+        assertEquals(3, EmailContent.count(mMockContext, Attachment.CONTENT_URI,
+                CANT_DOWNLOAD_SELECTION, null));
+        // Make sure the right one is downloadable
+        att4 = Attachment.restoreAttachmentWithId(mMockContext, att4.mId);
+        assertTrue((att4.mFlags & Attachment.FLAG_POLICY_DISALLOWS_DOWNLOAD) == 0);
+
+        Policy policy4 = new Policy();
+        // Switch to new policy that is without restrictions
+        Policy.setAttachmentFlagsForNewPolicy(mMockContext, acct, policy4);
+        // Nothing should be blocked now
+        assertEquals(0, EmailContent.count(mMockContext, Attachment.CONTENT_URI,
+                CANT_DOWNLOAD_SELECTION, null));
+   }
+
     public void testParcel() {
         Policy policy = new Policy();
         policy.mPasswordMode = Policy.PASSWORD_MODE_STRONG;