Download location: fix radio button double selection.

DownloadLocationPreference directly uses native pref to persist the
selection result. However the native pref may have a delay when
persisting the data, and the UI may refresh the view before native pref
is done, which causes double radio button selection.

This CL caches the selection ID so the UI can always get fresh data.


Bug: 842464,792775
Change-Id: I39bec3a61ea2c7f0e656658cfc41a62e12956560
Reviewed-on: https://chromium-review.googlesource.com/1070480
Commit-Queue: Xing Liu <xingliu@chromium.org>
Reviewed-by: Min Qin <qinmin@chromium.org>
Reviewed-by: David Trainor <dtrainor@chromium.org>
Cr-Commit-Position: refs/heads/master@{#561368}

chrome/android/java/src/org/chromium/chrome/browser/download/DownloadLocationDialog.java

@@ -100,7 +100,7 @@ public class DownloadLocationDialog extends ModalDialogView {
         if (selectedItemId == NO_SELECTED_ITEM_ID
                 || dialogType == DownloadLocationDialogType.LOCATION_FULL
                 || dialogType == DownloadLocationDialogType.LOCATION_NOT_FOUND) {
-            selectedItemId = mDirectoryAdapter.getFirstSelectableItemId();
+            selectedItemId = mDirectoryAdapter.useFirstValidSelectableItemId();
         }
         mFileLocation.setSelection(selectedItemId);
 

chrome/android/java/src/org/chromium/chrome/browser/preferences/download/DownloadDirectoryAdapter.java

@@ -33,6 +33,9 @@ import java.util.List;
  */
 public class DownloadDirectoryAdapter extends ArrayAdapter<Object> {
     public static int NO_SELECTED_ITEM_ID = -1;
+    public static int SELECTED_ITEM_NOT_INITIALIZED = -2;
+
+    protected int mSelectedPosition = SELECTED_ITEM_NOT_INITIALIZED;
 
     private Context mContext;
     private LayoutInflater mLayoutInflater;
@@ -150,6 +153,14 @@ public class DownloadDirectoryAdapter extends ArrayAdapter<Object> {
      *          NO_SELECTED_ITEM_ID if no item matches the default path.
      */
     public int getSelectedItemId() {
+        if (mSelectedPosition == SELECTED_ITEM_NOT_INITIALIZED) {
+            mSelectedPosition = initSelectedIdFromPref();
+        }
+
+        return mSelectedPosition;
+    }
+
+    private int initSelectedIdFromPref() {
         if (!mErrorOptions.isEmpty()) return 0;
         String defaultLocation = PrefServiceBridge.getInstance().getDownloadDefaultDirectory();
         for (int i = 0; i < getCount(); i++) {
@@ -167,13 +178,14 @@ public class DownloadDirectoryAdapter extends ArrayAdapter<Object> {
      *
      * @return  ID of the first valid, selectable item and the new default location.
      */
-    public int getFirstSelectableItemId() {
+    public int useFirstValidSelectableItemId() {
         for (int i = 0; i < getCount(); i++) {
             DirectoryOption option = (DirectoryOption) getItem(i);
             if (option == null) continue;
             if (option.availableSpace > 0) {
                 PrefServiceBridge.getInstance().setDownloadAndSaveFileDefaultDirectory(
                         option.location.getAbsolutePath());
+                mSelectedPosition = i;
                 return i;
             }
         }

chrome/android/java/src/org/chromium/chrome/browser/preferences/download/DownloadLocationPreferenceAdapter.java

@@ -35,6 +35,10 @@ public class DownloadLocationPreferenceAdapter
             Context context, DownloadLocationPreference preference) {
         super(context);
         mPreference = preference;
+
+        if (getSelectedItemId() == NO_SELECTED_ITEM_ID) {
+            useFirstValidSelectableItemId();
+        }
     }
 
     @Override
@@ -48,9 +52,8 @@ public class DownloadLocationPreferenceAdapter
         view.setTag(position);
         view.setOnClickListener(this);
 
-        boolean isSelected = (getSelectedItemId() == position);
         RadioButton radioButton = view.findViewById(R.id.radio_button);
-        radioButton.setChecked(isSelected);
+        radioButton.setChecked(getSelectedItemId() == position);
 
         view.setEnabled(isEnabled(position));
 
@@ -98,6 +101,8 @@ public class DownloadLocationPreferenceAdapter
         editor.apply();
         mPreference.setSummary(option.location.getAbsolutePath());
 
+        mSelectedPosition = selectedId;
+
         // Refresh the list of download directories UI.
         notifyDataSetChanged();
     }