Add drawer with state information

platform_tools/android/apps/viewer/src/main/java/org/skia/viewer/StateAdapter.java

Index: platform_tools/android/apps/viewer/src/main/java/org/skia/viewer/StateAdapter.java
diff --git a/platform_tools/android/apps/viewer/src/main/java/org/skia/viewer/StateAdapter.java b/platform_tools/android/apps/viewer/src/main/java/org/skia/viewer/StateAdapter.java
new file mode 100644
index 0000000000000000000000000000000000000000..4c9dcd4b847dbca88eb0706ee3fa3d9152ae5807
--- /dev/null
+++ b/platform_tools/android/apps/viewer/src/main/java/org/skia/viewer/StateAdapter.java
@@ -0,0 +1,114 @@
+package org.skia.viewer;
+
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.AdapterView;
+import android.widget.ArrayAdapter;
+import android.widget.BaseAdapter;
+import android.widget.Spinner;
+import android.widget.TextView;
+
+import org.json.JSONArray;
+import org.json.JSONException;
+import org.json.JSONObject;
+
+import java.util.ArrayList;
+
+public class StateAdapter extends BaseAdapter implements AdapterView.OnItemSelectedListener {
+    static final String NAME = "name";
+    static final String VALUE = "value";
+    static final String OPTIONS = "options";
+
+    ViewerActivity mViewerActivity;
+    JSONArray mStateJson;
+
+    public StateAdapter(ViewerActivity viewerActivity) {
+        mViewerActivity = viewerActivity;
+        try {
+            mStateJson = new JSONArray("[{\"name\": \"Please\", " +
+                    "\"value\": \"Initialize\", \"options\": []}]");
+        } catch (JSONException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public void setState(String stateJson) {
+        try {
+            mStateJson = new JSONArray(stateJson);
+            notifyDataSetChanged();
+        } catch (JSONException e) {
+            e.printStackTrace();
+        }
+    }
+
+    @Override
+    public int getCount() {
+        return mStateJson.length();
+    }
+
+    @Override
+    public Object getItem(int position) {
+        try {
+            return mStateJson.getJSONObject(position);
+        } catch (JSONException e) {
+            e.printStackTrace();
+            return null;
+        }
+    }
+
+    @Override
+    public long getItemId(int position) {
+        return 0;
+    }
+
+    @Override
+    public View getView(int position, View convertView, ViewGroup parent) {
+        if (convertView == null) {
+            convertView = LayoutInflater.from(mViewerActivity).inflate(R.layout.state_item, null);
+        }
+        TextView nameText = (TextView) convertView.findViewById(R.id.nameText);
+        TextView valueText = (TextView) convertView.findViewById(R.id.valueText);
+        Spinner optionSpinner = (Spinner) convertView.findViewById(R.id.optionSpinner);
+        JSONObject stateObject = (JSONObject) getItem(position);
+        try {
+            nameText.setText(stateObject.getString(NAME));
+            String value = stateObject.getString(VALUE);
+            JSONArray options = stateObject.getJSONArray(OPTIONS);
+            if (options.length() == 0) {
+                valueText.setText(value);
+                valueText.setVisibility(View.VISIBLE);
+                optionSpinner.setVisibility(View.GONE);
+
+            } else {
+                ArrayList<String> optionList = new ArrayList<>();
+                String[] optionStrings = new String[options.length()];
+                for(int i=0; i<options.length(); i++) {
+                    optionList.add(options.getString(i));
+                }
+                optionSpinner.setAdapter(new ArrayAdapter<String>(mViewerActivity,
+                        android.R.layout.simple_spinner_dropdown_item, optionList));
+                optionSpinner.setSelection(optionList.indexOf(value));
+                optionSpinner.setOnItemSelectedListener(this);
+                optionSpinner.setVisibility(View.VISIBLE);
+                valueText.setVisibility(View.GONE);
+            }
+        } catch (JSONException e) {
+            e.printStackTrace();
+        }
+        return convertView;
+    }
+
+    @Override
+    public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
+        View stateItem = (View) parent.getParent();
+        String stateName = ((TextView) stateItem.findViewById(R.id.nameText)).getText().toString();
+        String stateValue = ((TextView) view).getText().toString();
+        mViewerActivity.onStateChanged(stateName, stateValue);
+    }
+
+    @Override
+    public void onNothingSelected(AdapterView<?> parent) {
+        // do nothing
+    }
+}