Bug 975055 - Show previous filter for back row item. r=lucasr

mobile/android/base/home/PanelBackItemView.java

@@ -0,0 +1,30 @@
+/* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.gecko.home;
+
+import org.mozilla.gecko.R;
+
+import android.content.Context;
+import android.view.LayoutInflater;
+import android.widget.LinearLayout;
+import android.widget.TextView;
+
+class PanelBackItemView extends LinearLayout {
+    private final TextView title;
+
+    public PanelBackItemView(Context context) {
+        super(context);
+
+        LayoutInflater.from(context).inflate(R.layout.panel_back_item, this);
+        setOrientation(HORIZONTAL);
+
+        title = (TextView) findViewById(R.id.title);
+    }
+
+    public void updateFromFilter(String filter) {
+        title.setText(filter);
+    }
+}

mobile/android/base/home/PanelGridView.java

@@ -13,6 +13,7 @@ import org.mozilla.gecko.home.HomeConfig.ItemHandler;
 import org.mozilla.gecko.home.HomeConfig.ViewConfig;
 import org.mozilla.gecko.home.HomePager.OnUrlOpenListener;
 import org.mozilla.gecko.home.PanelLayout.DatasetBacked;
+import org.mozilla.gecko.home.PanelLayout.FilterManager;
 import org.mozilla.gecko.home.PanelLayout.PanelView;
 
 import android.content.Context;
@@ -57,6 +58,12 @@ public class PanelGridView extends GridView
         mUrlHandler.setOnUrlOpenListener(listener);
     }
 
+    @Override
+    public void setFilterManager(FilterManager filterManager) {
+        mAdapter.setFilterManager(filterManager);
+        mUrlHandler.setFilterManager(filterManager);
+    }
+
     private class PanelGridItemClickListener implements AdapterView.OnItemClickListener {
         @Override
         public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

mobile/android/base/home/PanelLayout.java

@@ -20,7 +20,6 @@ import android.view.KeyEvent;
 import android.view.View;
 import android.widget.FrameLayout;
 
-import java.util.Deque;
 import java.util.EnumSet;
 import java.util.LinkedList;
 import java.util.Map;
@@ -74,6 +73,7 @@ abstract class PanelLayout extends FrameLayout {
      */
     public interface DatasetBacked {
         public void setDataset(Cursor cursor);
+        public void setFilterManager(FilterManager manager);
     }
 
     /**
@@ -143,6 +143,12 @@ abstract class PanelLayout extends FrameLayout {
         public void setOnUrlOpenListener(OnUrlOpenListener listener);
     }
 
+    public interface FilterManager {
+        public String getPreviousFilter();
+        public boolean canGoBack();
+        public void goBack();
+    }
+
     public PanelLayout(Context context, PanelConfig panelConfig, DatasetHandler datasetHandler, OnUrlOpenListener urlOpenListener) {
         super(context);
         mViewStateMap = new WeakHashMap<View, ViewState>();
@@ -217,6 +223,11 @@ abstract class PanelLayout extends FrameLayout {
         ((PanelView) view).setOnUrlOpenListener(new PanelUrlOpenListener(state));
         view.setOnKeyListener(new PanelKeyListener(state));
 
+        if (view instanceof DatasetBacked) {
+            DatasetBacked datasetBacked = (DatasetBacked) view;
+            datasetBacked.setFilterManager(new PanelFilterManager(state));
+        }
+
         return view;
     }
 
@@ -268,7 +279,7 @@ abstract class PanelLayout extends FrameLayout {
      */
     protected static class ViewState {
         private final ViewConfig mViewConfig;
-        private Deque<String> mFilterStack;
+        private LinkedList<String> mFilterStack;
 
         public ViewState(ViewConfig viewConfig) {
             mViewConfig = viewConfig;
@@ -289,6 +300,17 @@ abstract class PanelLayout extends FrameLayout {
             }
         }
 
+        /**
+         * Get the previous filter that this view was displaying, or null if none.
+         */
+        public String getPreviousFilter() {
+            if (!canPopFilter()) {
+                return null;
+            }
+
+            return mFilterStack.get(1);
+        }
+
         /**
          * Adds a filter to the history stack for this view.
          */
@@ -383,4 +405,27 @@ abstract class PanelLayout extends FrameLayout {
             return false;
         }
     }
+
+    private class PanelFilterManager implements FilterManager {
+        private final ViewState mViewState;
+
+        public PanelFilterManager(ViewState viewState) {
+            mViewState = viewState;
+        }
+
+        @Override
+        public String getPreviousFilter() {
+            return mViewState.getPreviousFilter();
+        }
+
+        @Override
+        public boolean canGoBack() {
+            return mViewState.canPopFilter();
+        }
+
+        @Override
+        public void goBack() {
+            popFilterOnView(mViewState);
+        }
+    }
 }

mobile/android/base/home/PanelListView.java

@@ -12,6 +12,7 @@ import org.mozilla.gecko.home.HomeConfig.ItemHandler;
 import org.mozilla.gecko.home.HomeConfig.ViewConfig;
 import org.mozilla.gecko.home.HomePager.OnUrlOpenListener;
 import org.mozilla.gecko.home.PanelLayout.DatasetBacked;
+import org.mozilla.gecko.home.PanelLayout.FilterManager;
 import org.mozilla.gecko.home.PanelLayout.PanelView;
 
 import android.content.Context;
@@ -53,6 +54,12 @@ public class PanelListView extends HomeListView
         mUrlHandler.setOnUrlOpenListener(listener);
     }
 
+    @Override
+    public void setFilterManager(FilterManager filterManager) {
+        mAdapter.setFilterManager(filterManager);
+        mUrlHandler.setFilterManager(filterManager);
+    }
+
     private class PanelListItemClickListener implements AdapterView.OnItemClickListener {
         @Override
         public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

mobile/android/base/home/PanelViewAdapter.java

@@ -6,6 +6,9 @@
 package org.mozilla.gecko.home;
 
 import org.mozilla.gecko.home.HomeConfig.ItemType;
+import org.mozilla.gecko.home.PanelLayout.FilterManager;
+
+import org.mozilla.gecko.R;
 
 import android.content.Context;
 import android.database.Cursor;
@@ -14,8 +17,12 @@ import android.view.View;
 import android.view.ViewGroup;
 
 class PanelViewAdapter extends CursorAdapter {
+    private static final int VIEW_TYPE_ITEM = 0;
+    private static final int VIEW_TYPE_BACK = 1;
+
 	private final Context mContext;
 	private final ItemType mItemType;
+    private FilterManager mFilterManager;
 
     public PanelViewAdapter(Context context, ItemType itemType) {
         super(context, null, 0);
@@ -23,14 +30,83 @@ class PanelViewAdapter extends CursorAdapter {
         mItemType = itemType;
     }
 
+    public void setFilterManager(FilterManager manager) {
+        mFilterManager = manager;
+    }
+
     @Override
-    public void bindView(View view, Context context, Cursor cursor) {
+    public final int getViewTypeCount() {
+        return 2;
+    }
+
+    @Override
+    public int getCount() {
+        return super.getCount() + (isShowingBack() ? 1 : 0);
+    }
+
+    @Override
+    public int getItemViewType(int position) {
+        if (isShowingBack() && position == 0) {
+            return VIEW_TYPE_BACK;
+        } else {
+            return VIEW_TYPE_ITEM;
+        }
+    }
+
+    @Override
+    public final View getView(int position, View convertView, ViewGroup parent) {
+        if (convertView == null) {
+            convertView = newView(parent.getContext(), position, parent);
+        }
+
+        bindView(convertView, position);
+        return convertView;
+    }
+
+    private View newView(Context context, int position, ViewGroup parent) {
+        if (getItemViewType(position) == VIEW_TYPE_BACK) {
+            return new PanelBackItemView(context);
+        } else {
+            return PanelItemView.create(context, mItemType);
+        }
+    }
+
+    private void bindView(View view, int position) {
+        if (isShowingBack()) {
+            if (position == 0) {
+                final PanelBackItemView item = (PanelBackItemView) view;
+                item.updateFromFilter(mFilterManager.getPreviousFilter());
+                return;
+            }
+
+            position--;
+        }
+
+        final Cursor cursor = getCursor(position);
         final PanelItemView item = (PanelItemView) view;
         item.updateFromCursor(cursor);
     }
 
+    private boolean isShowingBack() {
+        return (mFilterManager != null ? mFilterManager.canGoBack() : false);
+    }
+
+    private final Cursor getCursor(int position) {
+        final Cursor cursor = getCursor();
+        if (cursor == null || !cursor.moveToPosition(position)) {
+            throw new IllegalStateException("Couldn't move cursor to position " + position);
+        }
+
+        return cursor;
+    }
+
     @Override
-    public View newView(Context context, Cursor cursor, ViewGroup parent) {
-        return PanelItemView.create(mContext, mItemType);
+    public final void bindView(View view, Context context, Cursor cursor) {
+        // Do nothing.
+    }
+
+    @Override
+    public final View newView(Context context, Cursor cursor, ViewGroup parent) {
+        return null;
     }
 }

mobile/android/base/home/PanelViewUrlHandler.java

@@ -9,6 +9,7 @@ import org.mozilla.gecko.db.BrowserContract.HomeItems;
 import org.mozilla.gecko.home.HomeConfig.ItemHandler;
 import org.mozilla.gecko.home.HomeConfig.ViewConfig;
 import org.mozilla.gecko.home.HomePager.OnUrlOpenListener;
+import org.mozilla.gecko.home.PanelLayout.FilterManager;
 
 import android.database.Cursor;
 
@@ -17,6 +18,7 @@ import java.util.EnumSet;
 class PanelViewUrlHandler {
     private final ViewConfig mViewConfig;
     private OnUrlOpenListener mUrlOpenListener;
+    private FilterManager mFilterManager;
 
     public PanelViewUrlHandler(ViewConfig viewConfig) {
         mViewConfig = viewConfig;
@@ -26,7 +28,25 @@ class PanelViewUrlHandler {
         mUrlOpenListener = listener;
     }
 
+    public void setFilterManager(FilterManager manager) {
+        mFilterManager = manager;
+    }
+
+    /**
+     * If item at this position is a back item, perform the go back action via the
+     * {@code FilterManager}. Otherwise, prepare the url to be opened by the
+     * {@code OnUrlOpenListener}.
+     */
     public void openUrlAtPosition(Cursor cursor, int position) {
+        if (mFilterManager != null && mFilterManager.canGoBack()) {
+            if (position == 0) {
+                mFilterManager.goBack();
+                return;
+            }
+
+            position--;
+        }
+
         if (cursor == null || !cursor.moveToPosition(position)) {
             throw new IllegalStateException("Couldn't move cursor to position " + position);
         }

mobile/android/base/moz.build

@@ -246,6 +246,7 @@ gbjar.sources += [
     'home/LastTabsPanel.java',
     'home/MostRecentPanel.java',
     'home/MultiTypeCursorAdapter.java',
+    'home/PanelBackItemView.java',
     'home/PanelGridView.java',
     'home/PanelItemView.java',
     'home/PanelLayout.java',

mobile/android/base/resources/layout/panel_back_item.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!-- This Source Code Form is subject to the terms of the Mozilla Public
+   - License, v. 2.0. If a copy of the MPL was not distributed with this
+   - file, You can obtain one at http://mozilla.org/MPL/2.0/. -->
+
+<merge xmlns:android="http://schemas.android.com/apk/res/android">
+
+    <TextView android:id="@+id/title"
+              style="@style/Widget.PanelItemView.Title"
+              android:layout_width="fill_parent"
+              android:layout_height="wrap_content"
+              android:paddingTop="5dip"
+              android:paddingBottom="5dip"
+              android:paddingLeft="10dip"
+              android:paddingRight="10dip"
+              android:minHeight="@dimen/page_row_height"
+              android:gravity="center_vertical"/>
+
+</merge>