Provide filter when there are many options

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2047233003

Review-Url: https://codereview.chromium.org/2047233003

2 files changed, 88 insertions, 5 deletions

diff --git a/platform_tools/android/apps/viewer/src/main/java/org/skia/viewer/OptionAdapter.java b/platform_tools/android/apps/viewer/src/main/java/org/skia/viewer/OptionAdapter.java
new file mode 100644
index 0000000000..4fefb54d8d
--- /dev/null
+++ b/platform_tools/android/apps/viewer/src/main/java/org/skia/viewer/OptionAdapter.java
@@ -0,0 +1,64 @@
+package org.skia.viewer;
+
+import android.content.Context;
+import android.widget.ArrayAdapter;
+import android.widget.Filter;
+import android.widget.Spinner;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class OptionAdapter extends ArrayAdapter<String> {
+    private String mCurrentOption;
+    private List<String> mOptions;
+    private Filter mFilter = null;
+    private Spinner mSpinner;
+
+    public OptionAdapter(Context context, int resource, List<String> options, Spinner spinner) {
+        super(context, resource);
+        addAll(options);
+        mOptions = options;
+        mSpinner = spinner;
+    }
+
+    public void setCurrentOption(String currentOption) {
+        this.mCurrentOption = currentOption;
+    }
+
+    private class OptionFilter extends Filter {
+
+        @Override
+        protected FilterResults performFiltering(CharSequence constraint) {
+            final String pattern = constraint.toString().toLowerCase();
+            ArrayList<String> filteredOptions = new ArrayList<>();
+            for(String option : mOptions) {
+                if (option.equals(mCurrentOption)
+                        || option.toLowerCase().indexOf(pattern) > -1) {
+                    filteredOptions.add(option);
+                }
+            }
+            FilterResults results = new FilterResults();
+            results.values = filteredOptions;
+            results.count = filteredOptions.size();
+            return results;
+        }
+
+        @Override
+        protected void publishResults(CharSequence constraint, FilterResults results) {
+            clear();
+            List<String> filteredOptions = (List<String>) results.values;
+            addAll(filteredOptions);
+            // We set the selection to the current option to avoid unwanted option selection change
+            mSpinner.setSelection(filteredOptions.indexOf(mCurrentOption));
+            notifyDataSetChanged();
+        }
+    }
+
+    @Override
+    public Filter getFilter() {
+        if (mFilter == null) {
+            mFilter = new OptionFilter();
+        }
+        return mFilter;
+    }
+}
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
index 5ee68efc3c..ba5407984b 100644
--- 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
@@ -1,12 +1,14 @@
 package org.skia.viewer;
 
+import android.text.Editable;
+import android.text.TextWatcher;
 import android.view.LayoutInflater;
 import android.view.SurfaceView;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.AdapterView;
-import android.widget.ArrayAdapter;
 import android.widget.BaseAdapter;
+import android.widget.EditText;
 import android.widget.LinearLayout;
 import android.widget.Spinner;
 import android.widget.TextView;
@@ -32,6 +34,7 @@ public class StateAdapter extends BaseAdapter implements AdapterView.OnItemSelec
     static final String VALUE = "value";
     static final String OPTIONS = "options";
     private static final String BACKEND_STATE_NAME = "Backend";
+    private static final int FILTER_LENGTH = 20;
 
     ViewerActivity mViewerActivity;
     LinearLayout mLayout;
@@ -86,7 +89,7 @@ public class StateAdapter extends BaseAdapter implements AdapterView.OnItemSelec
     }
 
     private View inflateItemView(JSONObject item) throws JSONException {
-        View itemView = LayoutInflater.from(mViewerActivity).inflate(R.layout.state_item, null);
+        LinearLayout itemView = (LinearLayout) LayoutInflater.from(mViewerActivity).inflate(R.layout.state_item, null);
         TextView nameText = (TextView) itemView.findViewById(R.id.nameText);
         TextView valueText = (TextView) itemView.findViewById(R.id.valueText);
         Spinner optionSpinner = (Spinner) itemView.findViewById(R.id.optionSpinner);
@@ -97,15 +100,31 @@ public class StateAdapter extends BaseAdapter implements AdapterView.OnItemSelec
             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 j = 0; j < options.length(); j++) {
                 optionList.add(options.getString(j));
             }
-            optionSpinner.setAdapter(new ArrayAdapter<String>(mViewerActivity,
-                    android.R.layout.simple_spinner_dropdown_item, optionList));
+            final OptionAdapter adapter = new OptionAdapter(mViewerActivity,
+                    android.R.layout.simple_spinner_dropdown_item, optionList, optionSpinner);
+            adapter.setCurrentOption(value);
+            optionSpinner.setAdapter(adapter);
+            if (optionStrings.length >= FILTER_LENGTH) {
+                EditText filterText = new EditText(mViewerActivity);
+                filterText.setHint("Filter");
+                itemView.addView(filterText, 1);
+                filterText.addTextChangedListener(new TextWatcher() {
+                    @Override
+                    public void beforeTextChanged(CharSequence s, int start, int cnt, int after) {}
+                    @Override
+                    public void onTextChanged(CharSequence s, int start, int before, int cnt) {}
+                    @Override
+                    public void afterTextChanged(Editable s) {
+                        adapter.getFilter().filter(s.toString());
+                    }
+                });
+            }
             optionSpinner.setSelection(optionList.indexOf(value));
             optionSpinner.setOnItemSelectedListener(this);
             optionSpinner.setVisibility(View.VISIBLE);