Truncate and ellipsize app name if too long for dialog.

If the given app name is too long for the permissions dialog, then
it can push the warning that the application will be able to record
the screen below the fold, letting the app basically set its own
dialog message in a way that a user would be difficult to detect as
fraudulant.

Bug: 23345192
Change-Id: If5881ca75d5c155ef5174351d245dbc3abdaa584

1 files changed, 50 insertions, 2 deletions

diff --git a/packages/SystemUI/src/com/android/systemui/media/MediaProjectionPermissionActivity.java b/packages/SystemUI/src/com/android/systemui/media/MediaProjectionPermissionActivity.java
index 2a84362..adc9b36 100644
--- a/packages/SystemUI/src/com/android/systemui/media/MediaProjectionPermissionActivity.java
+++ b/packages/SystemUI/src/com/android/systemui/media/MediaProjectionPermissionActivity.java
@@ -22,6 +22,7 @@ import android.content.DialogInterface;
 import android.content.Intent;
 import android.content.pm.ApplicationInfo;
 import android.content.pm.PackageManager;
+import android.graphics.Typeface;
 import android.media.projection.MediaProjectionManager;
 import android.media.projection.IMediaProjectionManager;
 import android.media.projection.IMediaProjection;
@@ -29,7 +30,14 @@ import android.os.Bundle;
 import android.os.IBinder;
 import android.os.RemoteException;
 import android.os.ServiceManager;
+import android.text.BidiFormatter;
+import android.text.Spannable;
+import android.text.SpannableString;
+import android.text.TextPaint;
+import android.text.TextUtils;
+import android.text.style.StyleSpan;
 import android.util.Log;
+import android.util.TypedValue;
 import android.view.WindowManager;
 import android.widget.CheckBox;
 import android.widget.CompoundButton;
@@ -39,6 +47,8 @@ public class MediaProjectionPermissionActivity extends Activity
         implements DialogInterface.OnClickListener, CheckBox.OnCheckedChangeListener,
         DialogInterface.OnCancelListener {
     private static final String TAG = "MediaProjectionPermissionActivity";
+    private static final float MAX_APP_NAME_SIZE_PX = 500f;
+    private static final String ELLIPSIS = "\u2026";
 
     private boolean mPermanentGrant;
     private String mPackageName;
@@ -84,11 +94,49 @@ public class MediaProjectionPermissionActivity extends Activity
             return;
         }
 
-        String appName = aInfo.loadLabel(packageManager).toString();
+        TextPaint paint = new TextPaint();
+        paint.setTextSize(42);
+
+        String label = aInfo.loadLabel(packageManager).toString();
+
+        // If the label contains new line characters it may push the security
+        // message below the fold of the dialog. Labels shouldn't have new line
+        // characters anyways, so just truncate the message the first time one
+        // is seen.
+        final int labelLength = label.length();
+        int offset = 0;
+        while (offset < labelLength) {
+            final int codePoint = label.codePointAt(offset);
+            final int type = Character.getType(codePoint);
+            if (type == Character.LINE_SEPARATOR
+                    || type == Character.CONTROL
+                    || type == Character.PARAGRAPH_SEPARATOR) {
+                label = label.substring(0, offset) + ELLIPSIS;
+                break;
+            }
+            offset += Character.charCount(codePoint);
+        }
+
+        if (label.isEmpty()) {
+            label = mPackageName;
+        }
+
+        String unsanitizedAppName = TextUtils.ellipsize(label,
+                paint, MAX_APP_NAME_SIZE_PX, TextUtils.TruncateAt.END).toString();
+        String appName = BidiFormatter.getInstance().unicodeWrap(unsanitizedAppName);
+
+        String actionText = getString(R.string.media_projection_dialog_text, appName);
+        SpannableString message = new SpannableString(actionText);
+
+        int appNameIndex = actionText.indexOf(appName);
+        if (appNameIndex >= 0) {
+            message.setSpan(new StyleSpan(Typeface.BOLD),
+                    appNameIndex, appNameIndex + appName.length(), 0);
+        }
 
         mDialog = new AlertDialog.Builder(this)
                 .setIcon(aInfo.loadIcon(packageManager))
-                .setMessage(getString(R.string.media_projection_dialog_text, appName))
+                .setMessage(message)
                 .setPositiveButton(R.string.media_projection_action_text, this)
                 .setNegativeButton(android.R.string.cancel, this)
                 .setView(R.layout.remember_permission_checkbox)