Implement a bluetooth picker dialog for Android

chrome/android/java/src/org/chromium/chrome/browser/ItemChooserDialog.java

Index: chrome/android/java/src/org/chromium/chrome/browser/ItemChooserDialog.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/ItemChooserDialog.java b/chrome/android/java/src/org/chromium/chrome/browser/ItemChooserDialog.java
index 6c92d6240828507a80d4aea4012f7601389e50fa..b64f4c74bb963133e68b3362e543aa9888b046c3 100644
--- a/chrome/android/java/src/org/chromium/chrome/browser/ItemChooserDialog.java
+++ b/chrome/android/java/src/org/chromium/chrome/browser/ItemChooserDialog.java
@@ -30,7 +30,9 @@ import org.chromium.chrome.R;
 import org.chromium.ui.base.DeviceFormFactor;
 import org.chromium.ui.widget.TextViewWithClickableSpans;
 
+import java.util.HashSet;
 import java.util.List;
+import java.util.Set;
 
 /**
  * A general-purpose dialog for presenting a list of things to pick from.
@@ -75,20 +77,36 @@ public class ItemChooserDialog {
         public final SpannableString mNoneFound;
         // A status message to show above the button row.
         public final SpannableString mStatus;
+        // An error state.
+        public final SpannableString mErrorMessage;
+        // A status message to go with the error state.
+        public final SpannableString mErrorStatus;
         // The label for the positive button (e.g. Select/Pair).
         public final String mPositiveButton;
 
         public ItemChooserLabels(SpannableString title, String searching, SpannableString noneFound,
-                SpannableString status, String positiveButton) {
+                SpannableString status, SpannableString errorMessage, SpannableString errorStatus,
+                String positiveButton) {
             mTitle = title;
             mSearching = searching;
             mNoneFound = noneFound;
             mStatus = status;
+            mErrorMessage = errorMessage;
+            mErrorStatus = errorStatus;
             mPositiveButton = positiveButton;
         }
     }
 
     /**
+     * The various states the dialog can represent.
+     */
+    private enum State {
+        STARTING,
+        PROGRESS_UPDATE_AVAILABLE,
+        SHOWING_ERROR,
+    }
+
+    /**
      * An adapter for keeping track of which items to show in the dialog.
      */
     private class ItemAdapter extends ArrayAdapter<ItemChooserRow>
@@ -105,6 +123,9 @@ public class ItemChooserDialog {
         // or -1 (INVALID_POSITION) if nothing is selected.
         private int mSelectedItem = ListView.INVALID_POSITION;
 
+        // A set of keys that are marked as unavailable for selection in the dialog.
+        private Set<String> mUnavailableEntries = new HashSet<String>();

[newt (away), 2015/09/01 21:51:23]

For consistent terminology with Android, let's use "enabled/disabled" instead of
"available/unavailable".

[Finnur, 2015/09/02 16:01:43]

Done.

+
         public ItemAdapter(Context context, int resource) {
             super(context, resource);
 
@@ -133,6 +154,24 @@ public class ItemChooserDialog {
             return row.mKey;
         }
 
+        /**
+         * Sets the availability of an item. Unavailable items are grayed out.
+         * @param id The id of the item to affect.
+         * @param available Whether the item should be available or not.
+         */
+        public void setAvailability(String id, boolean available) {
+            if (available) {
+                mUnavailableEntries.remove(id);
+            } else {
+                mUnavailableEntries.add(id);
+            }
+            notifyDataSetChanged();
+        }
+
+        private boolean isAvailable(String id) {

[newt (away), 2015/09/01 21:51:23]

ArrayAdapter has a method isEnabled(int position), which you should be
overriding (instead of checking isAvailable() in onItemClick()). If isEnabled()
returns false, then the view's state will be set to disabled and the user won't
be able to click the view. This will also work better with TalkBack for
accessibility.

[Finnur, 2015/09/02 16:01:43]

Ooh, I like that idea. Unfortunately, it makes it disabled but doesn't gray
anything out, but that's easy to fix.

[newt (away), 2015/09/02 17:48:42]

The view gets marked as "disabled". If the text color is a ColorStateList (e.g.
chrome/android/java/res/color/light_mode_tint.xml), then it will use the color
from the "disabled" state defined in the xml file. If the text color is just a
fixed color/integer (as in your case), then it doesn't change when its state is
"disabled".

So, you could use a ColorStateList, but I think the code you have is fine (and
simpler).

+            return !mUnavailableEntries.contains(id);
+        }
+
         @Override
         public int getViewTypeCount() {
             return 1;
@@ -163,12 +202,19 @@ public class ItemChooserDialog {
             }
 
             ItemChooserRow item = getItem(position);
+            if (!isAvailable(item.mKey)) {
+                view.setTextColor(Color.GRAY);
+            }
             view.setText(item.mDescription);
             return view;
         }
 
         @Override
         public void onItemClick(AdapterView<?> adapter, View view, int position, long id) {
+            ItemChooserRow item = getItem(position);
+            if (!isAvailable(item.mKey)) {
+                return;
+            }
             mSelectedItem = position;
             mConfirmButton.setEnabled(true);
             mItemAdapter.notifyDataSetChanged();
@@ -185,7 +231,7 @@ public class ItemChooserDialog {
 
     // Individual UI elements.
     private TextViewWithClickableSpans mTitle;
-    private TextViewWithClickableSpans mNotFoundMessage;
+    private TextViewWithClickableSpans mEmptyMessage;
     private ProgressBar mProgressBar;
     private ListView mListView;
     private TextView mStatus;
@@ -225,17 +271,14 @@ public class ItemChooserDialog {
         mStatus = (TextView) dialogContainer.findViewById(R.id.status);
         mTitle = (TextViewWithClickableSpans) dialogContainer.findViewById(
                 R.id.dialog_title);
-        mNotFoundMessage =
+        mEmptyMessage =

[newt (away), 2015/09/01 21:51:23]

remove wrapping (if possible)

[Finnur, 2015/09/02 16:01:43]

Done.

                 (TextViewWithClickableSpans) dialogContainer.findViewById(
                         R.id.not_found_message);
 
         mTitle.setText(labels.mTitle);
         mTitle.setMovementMethod(LinkMovementMethod.getInstance());
 
-        mNotFoundMessage.setText(labels.mNoneFound);
-        mNotFoundMessage.setMovementMethod(LinkMovementMethod.getInstance());
-
-        mStatus.setText(labels.mSearching);
+        mEmptyMessage.setMovementMethod(LinkMovementMethod.getInstance());
         mStatus.setMovementMethod(LinkMovementMethod.getInstance());
 
         mConfirmButton = (Button) dialogContainer.findViewById(R.id.positive);
@@ -252,10 +295,10 @@ public class ItemChooserDialog {
 
         mItemAdapter = new ItemAdapter(mContext, R.layout.item_chooser_dialog_row);
         mListView.setAdapter(mItemAdapter);
-        mListView.setEmptyView(mNotFoundMessage);
-        mNotFoundMessage.setVisibility(View.GONE);
+        mListView.setEmptyView(mEmptyMessage);
         mListView.setOnItemClickListener(mItemAdapter);
         mListView.setDivider(null);
+        setState(State.STARTING);
 
         // The list is the main element in the dialog and it should grow and
         // shrink according to the size of the screen available (clamped to a
@@ -296,6 +339,10 @@ public class ItemChooserDialog {
         mDialog.show();
     }
 
+    public void dismiss() {
+        mDialog.dismiss();
+    }
+
     /**
      * Add items to show in the dialog.
      *
@@ -306,17 +353,20 @@ public class ItemChooserDialog {
      */
     public void showList(List<ItemChooserRow> list) {
         mProgressBar.setVisibility(View.GONE);
-        mStatus.setText(mLabels.mStatus);
-
-        if (list.isEmpty()) {
-            boolean showEmptyMessage = mItemAdapter.isEmpty();
-            mNotFoundMessage.setVisibility(
-                    showEmptyMessage ? View.VISIBLE : View.GONE);
-            mListView.setVisibility(showEmptyMessage ? View.GONE : View.VISIBLE);
-        } else {
-            mListView.setVisibility(View.VISIBLE);
+
+        if (!list.isEmpty()) {
             mItemAdapter.addAll(list);
         }
+        setState(State.PROGRESS_UPDATE_AVAILABLE);
+    }
+
+    /**
+     * Sets the availability of an item.
+     * @param id The id of the item to affect.
+     * @param available Whether the item should be available or not.
+     */
+    public void setAvailability(String id, boolean available) {
+        mItemAdapter.setAvailability(id, available);
     }
 
     /**
@@ -324,5 +374,38 @@ public class ItemChooserDialog {
      */
     public void clear() {
         mItemAdapter.clear();
+        setState(State.STARTING);
+    }
+
+    /**
+     * Set the error state for the dialog.
+     */
+    public void setErrorState() {
+        setState(State.SHOWING_ERROR);
+    }
+
+    private void setState(State state) {
+        switch (state) {
+            case STARTING:
+                mStatus.setText(mLabels.mSearching);
+                mListView.setVisibility(View.GONE);
+                mProgressBar.setVisibility(View.VISIBLE);
+                break;
+            case SHOWING_ERROR:
+                mProgressBar.setVisibility(View.GONE);
+                mEmptyMessage.setText(mLabels.mErrorMessage);
+                mStatus.setText(mLabels.mErrorStatus);
+                break;
+            case PROGRESS_UPDATE_AVAILABLE:
+                mStatus.setText(mLabels.mStatus);
+                mProgressBar.setVisibility(View.GONE);
+                mListView.setVisibility(View.VISIBLE);
+
+                boolean showEmptyMessage = mItemAdapter.isEmpty();
+                mEmptyMessage.setText(mLabels.mNoneFound);
+                mEmptyMessage.setVisibility(
+                        showEmptyMessage ? View.VISIBLE : View.GONE);
+                break;
+        }
     }
 }