michael@0: /* -*- Mode: Java; c-basic-offset: 4; tab-width: 20; indent-tabs-mode: nil; -*-
michael@0:  * This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: package org.mozilla.gecko.home;
michael@0: 
michael@0: import org.mozilla.gecko.R;
michael@0: import org.mozilla.gecko.db.BrowserContract.HomeItems;
michael@0: import org.mozilla.gecko.home.HomePager.OnUrlOpenListener;
michael@0: import org.mozilla.gecko.home.HomeConfig.EmptyViewConfig;
michael@0: import org.mozilla.gecko.home.HomeConfig.ItemHandler;
michael@0: import org.mozilla.gecko.home.HomeConfig.PanelConfig;
michael@0: import org.mozilla.gecko.home.HomeConfig.ViewConfig;
michael@0: import org.mozilla.gecko.util.StringUtils;
michael@0: 
michael@0: import android.content.Context;
michael@0: import android.database.Cursor;
michael@0: import android.os.Parcel;
michael@0: import android.os.Parcelable;
michael@0: import android.text.TextUtils;
michael@0: import android.util.Log;
michael@0: import android.util.SparseArray;
michael@0: import android.view.KeyEvent;
michael@0: import android.view.LayoutInflater;
michael@0: import android.view.View;
michael@0: import android.view.ViewGroup;
michael@0: import android.widget.FrameLayout;
michael@0: import android.widget.ImageView;
michael@0: import android.widget.LinearLayout;
michael@0: import android.widget.TextView;
michael@0: 
michael@0: import java.lang.ref.SoftReference;
michael@0: import java.util.EnumSet;
michael@0: import java.util.LinkedList;
michael@0: import java.util.Map;
michael@0: import java.util.WeakHashMap;
michael@0: 
michael@0: import com.squareup.picasso.Picasso;
michael@0: 
michael@0: /**
michael@0:  * {@code PanelLayout} is the base class for custom layouts to be
michael@0:  * used in {@code DynamicPanel}. It provides the basic framework
michael@0:  * that enables custom layouts to request and reset datasets and
michael@0:  * create panel views. Furthermore, it automates most of the process
michael@0:  * of binding panel views with their respective datasets.
michael@0:  *
michael@0:  * {@code PanelLayout} abstracts the implemention details of how
michael@0:  * datasets are actually loaded through the {@DatasetHandler} interface.
michael@0:  * {@code DatasetHandler} provides two operations: request and reset.
michael@0:  * The results of the dataset requests done via the {@code DatasetHandler}
michael@0:  * are delivered to the {@code PanelLayout} with the {@code deliverDataset()}
michael@0:  * method.
michael@0:  *
michael@0:  * Subclasses of {@code PanelLayout} should simply use the utilities
michael@0:  * provided by {@code PanelLayout}. Namely:
michael@0:  *
michael@0:  * {@code requestDataset()} - To fetch datasets and auto-bind them to
michael@0:  *                            the existing panel views backed by them.
michael@0:  *
michael@0:  * {@code resetDataset()} - To release any resources associated with a
michael@0:  *                          previously loaded dataset.
michael@0:  *
michael@0:  * {@code createPanelView()} - To create a panel view for a ViewConfig
michael@0:  *                             associated with the panel.
michael@0:  *
michael@0:  * {@code disposePanelView()} - To dispose any dataset references associated
michael@0:  *                              with the given view.
michael@0:  *
michael@0:  * {@code PanelLayout} subclasses should always use {@code createPanelView()}
michael@0:  * to create the views dynamically created based on {@code ViewConfig}. This
michael@0:  * allows {@code PanelLayout} to auto-bind datasets with panel views.
michael@0:  * {@code PanelLayout} subclasses are free to have any type of views to arrange
michael@0:  * the panel views in different ways.
michael@0:  */
michael@0: abstract class PanelLayout extends FrameLayout {
michael@0:     private static final String LOGTAG = "GeckoPanelLayout";
michael@0: 
michael@0:     protected final SparseArray<ViewState> mViewStates;
michael@0:     private final PanelConfig mPanelConfig;
michael@0:     private final DatasetHandler mDatasetHandler;
michael@0:     private final OnUrlOpenListener mUrlOpenListener;
michael@0:     private final ContextMenuRegistry mContextMenuRegistry;
michael@0: 
michael@0:     /**
michael@0:      * To be used by panel views to express that they are
michael@0:      * backed by datasets.
michael@0:      */
michael@0:     public interface DatasetBacked {
michael@0:         public void setDataset(Cursor cursor);
michael@0:         public void setFilterManager(FilterManager manager);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * To be used by requests made to {@code DatasetHandler}s to couple dataset ID with current
michael@0:      * filter for queries on the database.
michael@0:      */
michael@0:     public static class DatasetRequest implements Parcelable {
michael@0:         public enum Type implements Parcelable {
michael@0:             DATASET_LOAD,
michael@0:             FILTER_PUSH,
michael@0:             FILTER_POP;
michael@0: 
michael@0:             @Override
michael@0:             public int describeContents() {
michael@0:                 return 0;
michael@0:             }
michael@0: 
michael@0:             @Override
michael@0:             public void writeToParcel(Parcel dest, int flags) {
michael@0:                 dest.writeInt(ordinal());
michael@0:             }
michael@0: 
michael@0:             public static final Creator<Type> CREATOR = new Creator<Type>() {
michael@0:                 @Override
michael@0:                 public Type createFromParcel(final Parcel source) {
michael@0:                     return Type.values()[source.readInt()];
michael@0:                 }
michael@0: 
michael@0:                 @Override
michael@0:                 public Type[] newArray(final int size) {
michael@0:                     return new Type[size];
michael@0:                 }
michael@0:             };
michael@0:         }
michael@0: 
michael@0:         private final int mViewIndex;
michael@0:         private final Type mType;
michael@0:         private final String mDatasetId;
michael@0:         private final FilterDetail mFilterDetail;
michael@0: 
michael@0:         private DatasetRequest(Parcel in) {
michael@0:             this.mViewIndex = in.readInt();
michael@0:             this.mType = (Type) in.readParcelable(getClass().getClassLoader());
michael@0:             this.mDatasetId = in.readString();
michael@0:             this.mFilterDetail = (FilterDetail) in.readParcelable(getClass().getClassLoader());
michael@0:         }
michael@0: 
michael@0:         public DatasetRequest(int index, String datasetId, FilterDetail filterDetail) {
michael@0:             this(index, Type.DATASET_LOAD, datasetId, filterDetail);
michael@0:         }
michael@0: 
michael@0:         public DatasetRequest(int index, Type type, String datasetId, FilterDetail filterDetail) {
michael@0:             this.mViewIndex = index;
michael@0:             this.mType = type;
michael@0:             this.mDatasetId = datasetId;
michael@0:             this.mFilterDetail = filterDetail;
michael@0:         }
michael@0: 
michael@0:         public int getViewIndex() {
michael@0:             return mViewIndex;
michael@0:         }
michael@0: 
michael@0:         public Type getType() {
michael@0:             return mType;
michael@0:         }
michael@0: 
michael@0:         public String getDatasetId() {
michael@0:             return mDatasetId;
michael@0:         }
michael@0: 
michael@0:         public String getFilter() {
michael@0:             return (mFilterDetail != null ? mFilterDetail.filter : null);
michael@0:         }
michael@0: 
michael@0:         public FilterDetail getFilterDetail() {
michael@0:             return mFilterDetail;
michael@0:         }
michael@0: 
michael@0:         @Override
michael@0:         public int describeContents() {
michael@0:             return 0;
michael@0:         }
michael@0: 
michael@0:         @Override
michael@0:         public void writeToParcel(Parcel dest, int flags) {
michael@0:             dest.writeInt(mViewIndex);
michael@0:             dest.writeParcelable(mType, 0);
michael@0:             dest.writeString(mDatasetId);
michael@0:             dest.writeParcelable(mFilterDetail, 0);
michael@0:         }
michael@0: 
michael@0:         public String toString() {
michael@0:             return "{ index: " + mViewIndex +
michael@0:                    ", type: " + mType +
michael@0:                    ", dataset: " + mDatasetId +
michael@0:                    ", filter: " + mFilterDetail +
michael@0:                    " }";
michael@0:         }
michael@0: 
michael@0:         public static final Creator<DatasetRequest> CREATOR = new Creator<DatasetRequest>() {
michael@0:             public DatasetRequest createFromParcel(Parcel in) {
michael@0:                 return new DatasetRequest(in);
michael@0:             }
michael@0: 
michael@0:             public DatasetRequest[] newArray(int size) {
michael@0:                 return new DatasetRequest[size];
michael@0:             }
michael@0:         };
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Defines the contract with the component that is responsible
michael@0:      * for handling datasets requests.
michael@0:      */
michael@0:     public interface DatasetHandler {
michael@0:         /**
michael@0:          * Requests a dataset to be fetched and auto-bound to the
michael@0:          * panel views backed by it.
michael@0:          */
michael@0:         public void requestDataset(DatasetRequest request);
michael@0: 
michael@0:         /**
michael@0:          * Releases any resources associated with a panel view. It will
michael@0:          * do nothing if the view with the given index been created
michael@0:          * before.
michael@0:          */
michael@0:         public void resetDataset(int viewIndex);
michael@0:     }
michael@0: 
michael@0:     public interface PanelView {
michael@0:         public void setOnItemOpenListener(OnItemOpenListener listener);
michael@0:         public void setOnKeyListener(OnKeyListener listener);
michael@0:         public void setContextMenuInfoFactory(HomeContextMenuInfo.Factory factory);
michael@0:     }
michael@0: 
michael@0:     public interface FilterManager {
michael@0:         public FilterDetail getPreviousFilter();
michael@0:         public boolean canGoBack();
michael@0:         public void goBack();
michael@0:     }
michael@0: 
michael@0:     public interface ContextMenuRegistry {
michael@0:         public void register(View view);
michael@0:     }
michael@0: 
michael@0:     public PanelLayout(Context context, PanelConfig panelConfig, DatasetHandler datasetHandler,
michael@0:             OnUrlOpenListener urlOpenListener, ContextMenuRegistry contextMenuRegistry) {
michael@0:         super(context);
michael@0:         mViewStates = new SparseArray<ViewState>();
michael@0:         mPanelConfig = panelConfig;
michael@0:         mDatasetHandler = datasetHandler;
michael@0:         mUrlOpenListener = urlOpenListener;
michael@0:         mContextMenuRegistry = contextMenuRegistry;
michael@0:     }
michael@0: 
michael@0:     @Override
michael@0:     public void onDetachedFromWindow() {
michael@0:         super.onDetachedFromWindow();
michael@0: 
michael@0:         final int count = mViewStates.size();
michael@0:         for (int i = 0; i < count; i++) {
michael@0:             final ViewState viewState = mViewStates.valueAt(i);
michael@0: 
michael@0:             final View view = viewState.getView();
michael@0:             if (view != null) {
michael@0:                 maybeSetDataset(view, null);
michael@0:             }
michael@0:         }
michael@0:         mViewStates.clear();
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Delivers the dataset as a {@code Cursor} to be bound to the
michael@0:      * panel view backed by it. This is used by the {@code DatasetHandler}
michael@0:      * in response to a dataset request.
michael@0:      */
michael@0:     public final void deliverDataset(DatasetRequest request, Cursor cursor) {
michael@0:         Log.d(LOGTAG, "Delivering request: " + request);
michael@0:         final ViewState viewState = mViewStates.get(request.getViewIndex());
michael@0:         if (viewState == null) {
michael@0:             return;
michael@0:         }
michael@0: 
michael@0:         switch (request.getType()) {
michael@0:             case FILTER_PUSH:
michael@0:                 viewState.pushFilter(request.getFilterDetail());
michael@0:                 break;
michael@0:             case FILTER_POP:
michael@0:                 viewState.popFilter();
michael@0:                 break;
michael@0:         }
michael@0: 
michael@0:         final View activeView = viewState.getActiveView();
michael@0:         if (activeView == null) {
michael@0:             throw new IllegalStateException("No active view for view state: " + viewState.getIndex());
michael@0:         }
michael@0: 
michael@0:         final ViewConfig viewConfig = viewState.getViewConfig();
michael@0: 
michael@0:         final View newView;
michael@0:         if (cursor == null || cursor.getCount() == 0) {
michael@0:             newView = createEmptyView(viewConfig);
michael@0:             maybeSetDataset(activeView, null);
michael@0:         } else {
michael@0:             newView = createPanelView(viewConfig);
michael@0:             maybeSetDataset(newView, cursor);
michael@0:         }
michael@0: 
michael@0:         if (activeView != newView) {
michael@0:             replacePanelView(activeView, newView);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Releases any references to the given dataset from all
michael@0:      * existing panel views.
michael@0:      */
michael@0:     public final void releaseDataset(int viewIndex) {
michael@0:         Log.d(LOGTAG, "Releasing dataset: " + viewIndex);
michael@0:         final ViewState viewState = mViewStates.get(viewIndex);
michael@0:         if (viewState == null) {
michael@0:             return;
michael@0:         }
michael@0: 
michael@0:         final View view = viewState.getView();
michael@0:         if (view != null) {
michael@0:             maybeSetDataset(view, null);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Requests a dataset to be loaded and bound to any existing
michael@0:      * panel view backed by it.
michael@0:      */
michael@0:     protected final void requestDataset(DatasetRequest request) {
michael@0:         Log.d(LOGTAG, "Requesting request: " + request);
michael@0:         if (mViewStates.get(request.getViewIndex()) == null) {
michael@0:             return;
michael@0:         }
michael@0: 
michael@0:         mDatasetHandler.requestDataset(request);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Releases any resources associated with a panel view.
michael@0:      * e.g. close any associated {@code Cursor}.
michael@0:      */
michael@0:     protected final void resetDataset(int viewIndex) {
michael@0:         Log.d(LOGTAG, "Resetting view with index: " + viewIndex);
michael@0:         if (mViewStates.get(viewIndex) == null) {
michael@0:             return;
michael@0:         }
michael@0: 
michael@0:         mDatasetHandler.resetDataset(viewIndex);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Factory method to create instance of panels from a given
michael@0:      * {@code ViewConfig}. All panel views defined in {@code PanelConfig}
michael@0:      * should be created using this method so that {@PanelLayout} can
michael@0:      * keep track of panel views and their associated datasets.
michael@0:      */
michael@0:     protected final View createPanelView(ViewConfig viewConfig) {
michael@0:         Log.d(LOGTAG, "Creating panel view: " + viewConfig.getType());
michael@0: 
michael@0:         ViewState viewState = mViewStates.get(viewConfig.getIndex());
michael@0:         if (viewState == null) {
michael@0:             viewState = new ViewState(viewConfig);
michael@0:             mViewStates.put(viewConfig.getIndex(), viewState);
michael@0:         }
michael@0: 
michael@0:         View view = viewState.getView();
michael@0:         if (view == null) {
michael@0:             switch(viewConfig.getType()) {
michael@0:                 case LIST:
michael@0:                     view = new PanelListView(getContext(), viewConfig);
michael@0:                     break;
michael@0: 
michael@0:                 case GRID:
michael@0:                     view = new PanelGridView(getContext(), viewConfig);
michael@0:                     break;
michael@0: 
michael@0:                 default:
michael@0:                     throw new IllegalStateException("Unrecognized view type in " + getClass().getSimpleName());
michael@0:             }
michael@0: 
michael@0:             PanelView panelView = (PanelView) view;
michael@0:             panelView.setOnItemOpenListener(new PanelOnItemOpenListener(viewState));
michael@0:             panelView.setOnKeyListener(new PanelKeyListener(viewState));
michael@0:             panelView.setContextMenuInfoFactory(new HomeContextMenuInfo.Factory() {
michael@0:                 @Override
michael@0:                 public HomeContextMenuInfo makeInfoForCursor(View view, int position, long id, Cursor cursor) {
michael@0:                     final HomeContextMenuInfo info = new HomeContextMenuInfo(view, position, id);
michael@0:                     info.url = cursor.getString(cursor.getColumnIndexOrThrow(HomeItems.URL));
michael@0:                     info.title = cursor.getString(cursor.getColumnIndexOrThrow(HomeItems.TITLE));
michael@0:                     return info;
michael@0:                 }
michael@0:             });
michael@0: 
michael@0:             mContextMenuRegistry.register(view);
michael@0: 
michael@0:             if (view instanceof DatasetBacked) {
michael@0:                 DatasetBacked datasetBacked = (DatasetBacked) view;
michael@0:                 datasetBacked.setFilterManager(new PanelFilterManager(viewState));
michael@0: 
michael@0:                 // XXX: Disabled because of bug 1010986
michael@0:                 // if (viewConfig.isRefreshEnabled()) {
michael@0:                 //     view = new PanelRefreshLayout(getContext(), view,
michael@0:                 //                                   mPanelConfig.getId(), viewConfig.getIndex());
michael@0:                 // }
michael@0:             }
michael@0: 
michael@0:             viewState.setView(view);
michael@0:         }
michael@0: 
michael@0:         return view;
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Dispose any dataset references associated with the
michael@0:      * given view.
michael@0:      */
michael@0:     protected final void disposePanelView(View view) {
michael@0:         Log.d(LOGTAG, "Disposing panel view");
michael@0:         final int count = mViewStates.size();
michael@0:         for (int i = 0; i < count; i++) {
michael@0:             final ViewState viewState = mViewStates.valueAt(i);
michael@0: 
michael@0:             if (viewState.getView() == view) {
michael@0:                 maybeSetDataset(view, null);
michael@0:                 mViewStates.remove(viewState.getIndex());
michael@0:                 break;
michael@0:             }
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     private void maybeSetDataset(View view, Cursor cursor) {
michael@0:         if (view instanceof DatasetBacked) {
michael@0:             final DatasetBacked dsb = (DatasetBacked) view;
michael@0:             dsb.setDataset(cursor);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     private View createEmptyView(ViewConfig viewConfig) {
michael@0:         Log.d(LOGTAG, "Creating empty view: " + viewConfig.getType());
michael@0: 
michael@0:         ViewState viewState = mViewStates.get(viewConfig.getIndex());
michael@0:         if (viewState == null) {
michael@0:             throw new IllegalStateException("No view state found for view index: " + viewConfig.getIndex());
michael@0:         }
michael@0: 
michael@0:         View view = viewState.getEmptyView();
michael@0:         if (view == null) {
michael@0:             view = LayoutInflater.from(getContext()).inflate(R.layout.home_empty_panel, null);
michael@0: 
michael@0:             final EmptyViewConfig emptyViewConfig = viewConfig.getEmptyViewConfig();
michael@0: 
michael@0:             // XXX: Refactor this into a custom view (bug 985134)
michael@0:             final String text = (emptyViewConfig == null) ? null : emptyViewConfig.getText();
michael@0:             final TextView textView = (TextView) view.findViewById(R.id.home_empty_text);
michael@0:             if (TextUtils.isEmpty(text)) {
michael@0:                 textView.setText(R.string.home_default_empty);
michael@0:             } else {
michael@0:                 textView.setText(text);
michael@0:             }
michael@0: 
michael@0:             final String imageUrl = (emptyViewConfig == null) ? null : emptyViewConfig.getImageUrl();
michael@0:             final ImageView imageView = (ImageView) view.findViewById(R.id.home_empty_image);
michael@0: 
michael@0:             if (TextUtils.isEmpty(imageUrl)) {
michael@0:                 imageView.setImageResource(R.drawable.icon_home_empty_firefox);
michael@0:             } else {
michael@0:                 Picasso.with(getContext())
michael@0:                        .load(imageUrl)
michael@0:                        .error(R.drawable.icon_home_empty_firefox)
michael@0:                        .into(imageView);
michael@0:             }
michael@0: 
michael@0:             viewState.setEmptyView(view);
michael@0:         }
michael@0: 
michael@0:         return view;
michael@0:     }
michael@0: 
michael@0:     private void replacePanelView(View currentView, View newView) {
michael@0:         final ViewGroup parent = (ViewGroup) currentView.getParent();
michael@0:         parent.addView(newView, parent.indexOfChild(currentView), currentView.getLayoutParams());
michael@0:         parent.removeView(currentView);
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Must be implemented by {@code PanelLayout} subclasses to define
michael@0:      * what happens then the layout is first loaded. Should set initial
michael@0:      * UI state and request any necessary datasets.
michael@0:      */
michael@0:     public abstract void load();
michael@0: 
michael@0:     /**
michael@0:      * Represents a 'live' instance of a panel view associated with
michael@0:      * the {@code PanelLayout}. Is responsible for tracking the history stack of filters.
michael@0:      */
michael@0:     protected class ViewState {
michael@0:         private final ViewConfig mViewConfig;
michael@0:         private SoftReference<View> mView;
michael@0:         private SoftReference<View> mEmptyView;
michael@0:         private LinkedList<FilterDetail> mFilterStack;
michael@0: 
michael@0:         public ViewState(ViewConfig viewConfig) {
michael@0:             mViewConfig = viewConfig;
michael@0:             mView = new SoftReference<View>(null);
michael@0:             mEmptyView = new SoftReference<View>(null);
michael@0:         }
michael@0: 
michael@0:         public ViewConfig getViewConfig() {
michael@0:             return mViewConfig;
michael@0:         }
michael@0: 
michael@0:         public int getIndex() {
michael@0:             return mViewConfig.getIndex();
michael@0:         }
michael@0: 
michael@0:         public View getView() {
michael@0:             return mView.get();
michael@0:         }
michael@0: 
michael@0:         public void setView(View view) {
michael@0:             mView = new SoftReference<View>(view);
michael@0:         }
michael@0: 
michael@0:         public View getEmptyView() {
michael@0:             return mEmptyView.get();
michael@0:         }
michael@0: 
michael@0:         public void setEmptyView(View view) {
michael@0:             mEmptyView = new SoftReference<View>(view);
michael@0:         }
michael@0: 
michael@0:         public View getActiveView() {
michael@0:             final View view = getView();
michael@0:             if (view != null && view.getParent() != null) {
michael@0:                 return view;
michael@0:             }
michael@0: 
michael@0:             final View emptyView = getEmptyView();
michael@0:             if (emptyView != null && emptyView.getParent() != null) {
michael@0:                 return emptyView;
michael@0:             }
michael@0: 
michael@0:             return null;
michael@0:         }
michael@0: 
michael@0:         public String getDatasetId() {
michael@0:             return mViewConfig.getDatasetId();
michael@0:         }
michael@0: 
michael@0:         public ItemHandler getItemHandler() {
michael@0:             return mViewConfig.getItemHandler();
michael@0:         }
michael@0: 
michael@0:         /**
michael@0:          * Get the current filter that this view is displaying, or null if none.
michael@0:          */
michael@0:         public FilterDetail getCurrentFilter() {
michael@0:             if (mFilterStack == null) {
michael@0:                 return null;
michael@0:             } else {
michael@0:                 return mFilterStack.peek();
michael@0:             }
michael@0:         }
michael@0: 
michael@0:         /**
michael@0:          * Get the previous filter that this view was displaying, or null if none.
michael@0:          */
michael@0:         public FilterDetail getPreviousFilter() {
michael@0:             if (!canPopFilter()) {
michael@0:                 return null;
michael@0:             }
michael@0: 
michael@0:             return mFilterStack.get(1);
michael@0:         }
michael@0: 
michael@0:         /**
michael@0:          * Adds a filter to the history stack for this view.
michael@0:          */
michael@0:         public void pushFilter(FilterDetail filter) {
michael@0:             if (mFilterStack == null) {
michael@0:                 mFilterStack = new LinkedList<FilterDetail>();
michael@0: 
michael@0:                 // Initialize with the initial filter.
michael@0:                 mFilterStack.push(new FilterDetail(mViewConfig.getFilter(),
michael@0:                                                    mPanelConfig.getTitle()));
michael@0:             }
michael@0: 
michael@0:             mFilterStack.push(filter);
michael@0:         }
michael@0: 
michael@0:         /**
michael@0:          * Remove the most recent filter from the stack.
michael@0:          *
michael@0:          * @return whether the filter was popped
michael@0:          */
michael@0:         public boolean popFilter() {
michael@0:             if (!canPopFilter()) {
michael@0:                 return false;
michael@0:             }
michael@0: 
michael@0:             mFilterStack.pop();
michael@0:             return true;
michael@0:         }
michael@0: 
michael@0:         public boolean canPopFilter() {
michael@0:             return (mFilterStack != null && mFilterStack.size() > 1);
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     static class FilterDetail implements Parcelable {
michael@0:         final String filter;
michael@0:         final String title;
michael@0: 
michael@0:         private FilterDetail(Parcel in) {
michael@0:             this.filter = in.readString();
michael@0:             this.title = in.readString();
michael@0:         }
michael@0: 
michael@0:         public FilterDetail(String filter, String title) {
michael@0:             this.filter = filter;
michael@0:             this.title = title;
michael@0:         }
michael@0: 
michael@0:         @Override
michael@0:         public int describeContents() {
michael@0:             return 0;
michael@0:         }
michael@0: 
michael@0:         @Override
michael@0:         public void writeToParcel(Parcel dest, int flags) {
michael@0:             dest.writeString(filter);
michael@0:             dest.writeString(title);
michael@0:         }
michael@0: 
michael@0:         public static final Creator<FilterDetail> CREATOR = new Creator<FilterDetail>() {
michael@0:             public FilterDetail createFromParcel(Parcel in) {
michael@0:                 return new FilterDetail(in);
michael@0:             }
michael@0: 
michael@0:             public FilterDetail[] newArray(int size) {
michael@0:                 return new FilterDetail[size];
michael@0:             }
michael@0:         };
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Pushes filter to {@code ViewState}'s stack and makes request for new filter value.
michael@0:      */
michael@0:     private void pushFilterOnView(ViewState viewState, FilterDetail filterDetail) {
michael@0:         final int index = viewState.getIndex();
michael@0:         final String datasetId = viewState.getDatasetId();
michael@0: 
michael@0:         mDatasetHandler.requestDataset(new DatasetRequest(index,
michael@0:                                                           DatasetRequest.Type.FILTER_PUSH,
michael@0:                                                           datasetId,
michael@0:                                                           filterDetail));
michael@0:     }
michael@0: 
michael@0:     /**
michael@0:      * Pops filter from {@code ViewState}'s stack and makes request for previous filter value.
michael@0:      *
michael@0:      * @return whether the filter has changed
michael@0:      */
michael@0:     private boolean popFilterOnView(ViewState viewState) {
michael@0:         if (viewState.canPopFilter()) {
michael@0:             final int index = viewState.getIndex();
michael@0:             final String datasetId = viewState.getDatasetId();
michael@0:             final FilterDetail filterDetail = viewState.getPreviousFilter();
michael@0: 
michael@0:             mDatasetHandler.requestDataset(new DatasetRequest(index,
michael@0:                                                               DatasetRequest.Type.FILTER_POP,
michael@0:                                                               datasetId,
michael@0:                                                               filterDetail));
michael@0: 
michael@0:             return true;
michael@0:         } else {
michael@0:             return false;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     public interface OnItemOpenListener {
michael@0:         public void onItemOpen(String url, String title);
michael@0:     }
michael@0: 
michael@0:     private class PanelOnItemOpenListener implements OnItemOpenListener {
michael@0:         private ViewState mViewState;
michael@0: 
michael@0:         public PanelOnItemOpenListener(ViewState viewState) {
michael@0:             mViewState = viewState;
michael@0:         }
michael@0: 
michael@0:         @Override
michael@0:         public void onItemOpen(String url, String title) {
michael@0:             if (StringUtils.isFilterUrl(url)) {
michael@0:                 FilterDetail filterDetail = new FilterDetail(StringUtils.getFilterFromUrl(url), title);
michael@0:                 pushFilterOnView(mViewState, filterDetail);
michael@0:             } else {
michael@0:                 EnumSet<OnUrlOpenListener.Flags> flags = EnumSet.noneOf(OnUrlOpenListener.Flags.class);
michael@0:                 if (mViewState.getItemHandler() == ItemHandler.INTENT) {
michael@0:                     flags.add(OnUrlOpenListener.Flags.OPEN_WITH_INTENT);
michael@0:                 }
michael@0: 
michael@0:                 mUrlOpenListener.onUrlOpen(url, flags);
michael@0:             }
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     private class PanelKeyListener implements View.OnKeyListener {
michael@0:         private ViewState mViewState;
michael@0: 
michael@0:         public PanelKeyListener(ViewState viewState) {
michael@0:             mViewState = viewState;
michael@0:         }
michael@0: 
michael@0:         @Override
michael@0:         public boolean onKey(View v, int keyCode, KeyEvent event) {
michael@0:             if (event.getAction() == KeyEvent.ACTION_UP && keyCode == KeyEvent.KEYCODE_BACK) {
michael@0:                 return popFilterOnView(mViewState);
michael@0:             }
michael@0: 
michael@0:             return false;
michael@0:         }
michael@0:     }
michael@0: 
michael@0:     private class PanelFilterManager implements FilterManager {
michael@0:         private final ViewState mViewState;
michael@0: 
michael@0:         public PanelFilterManager(ViewState viewState) {
michael@0:             mViewState = viewState;
michael@0:         }
michael@0: 
michael@0:         @Override
michael@0:         public FilterDetail getPreviousFilter() {
michael@0:             return mViewState.getPreviousFilter();
michael@0:         }
michael@0: 
michael@0:         @Override
michael@0:         public boolean canGoBack() {
michael@0:             return mViewState.canPopFilter();
michael@0:         }
michael@0: 
michael@0:         @Override
michael@0:         public void goBack() {
michael@0:             popFilterOnView(mViewState);
michael@0:         }
michael@0:     }
michael@0: }