--- /dev/null
+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.photos.views;
+
+import android.content.Context;
+import android.database.DataSetObservable;
+import android.database.DataSetObserver;
+import android.util.AttributeSet;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.AdapterView;
+import android.widget.Filter;
+import android.widget.Filterable;
+import android.widget.FrameLayout;
+import android.widget.GridView;
+import android.widget.ListAdapter;
+import android.widget.WrapperListAdapter;
+
+import java.util.ArrayList;
+
+/**
+ * A {@link GridView} that supports adding header rows in a
+ * very similar way to {@link ListView}.
+ * See {@link HeaderGridView#addHeaderView(View, Object, boolean)}
+ */
+public class HeaderGridView extends GridView {
+ private static final String TAG = "HeaderGridView";
+
+ /**
+ * A class that represents a fixed view in a list, for example a header at the top
+ * or a footer at the bottom.
+ */
+ private static class FixedViewInfo {
+ /** The view to add to the grid */
+ public View view;
+ public ViewGroup viewContainer;
+ /** The data backing the view. This is returned from {@link ListAdapter#getItem(int)}. */
+ public Object data;
+ /** <code>true</code> if the fixed view should be selectable in the grid */
+ public boolean isSelectable;
+ }
+
+ private ArrayList<FixedViewInfo> mHeaderViewInfos = new ArrayList<FixedViewInfo>();
+
+ private void initHeaderGridView() {
+ super.setClipChildren(false);
+ }
+
+ public HeaderGridView(Context context) {
+ super(context);
+ initHeaderGridView();
+ }
+
+ public HeaderGridView(Context context, AttributeSet attrs) {
+ super(context, attrs);
+ initHeaderGridView();
+ }
+
+ public HeaderGridView(Context context, AttributeSet attrs, int defStyle) {
+ super(context, attrs, defStyle);
+ initHeaderGridView();
+ }
+
+ @Override
+ protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+ super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+ ListAdapter adapter = getAdapter();
+ if (adapter != null && adapter instanceof HeaderViewGridAdapter) {
+ ((HeaderViewGridAdapter) adapter).setNumColumns(getNumColumns());
+ }
+ }
+
+ @Override
+ public void setClipChildren(boolean clipChildren) {
+ // Ignore, since the header rows depend on not being clipped
+ }
+
+ /**
+ * Add a fixed view to appear at the top of the grid. If addHeaderView is
+ * called more than once, the views will appear in the order they were
+ * added. Views added using this call can take focus if they want.
+ * <p>
+ * NOTE: Call this before calling setAdapter. This is so HeaderGridView can wrap
+ * the supplied cursor with one that will also account for header views.
+ *
+ * @param v The view to add.
+ * @param data Data to associate with this view
+ * @param isSelectable whether the item is selectable
+ */
+ public void addHeaderView(View v, Object data, boolean isSelectable) {
+ ListAdapter adapter = getAdapter();
+
+ if (adapter != null && ! (adapter instanceof HeaderViewGridAdapter)) {
+ throw new IllegalStateException(
+ "Cannot add header view to grid -- setAdapter has already been called.");
+ }
+
+ FixedViewInfo info = new FixedViewInfo();
+ FrameLayout fl = new FullWidthFixedViewLayout(getContext());
+ fl.addView(v);
+ info.view = v;
+ info.viewContainer = fl;
+ info.data = data;
+ info.isSelectable = isSelectable;
+ mHeaderViewInfos.add(info);
+
+ // in the case of re-adding a header view, or adding one later on,
+ // we need to notify the observer
+ if (adapter != null) {
+ ((HeaderViewGridAdapter) adapter).notifyDataSetChanged();
+ }
+ }
+
+ /**
+ * Add a fixed view to appear at the top of the grid. If addHeaderView is
+ * called more than once, the views will appear in the order they were
+ * added. Views added using this call can take focus if they want.
+ * <p>
+ * NOTE: Call this before calling setAdapter. This is so HeaderGridView can wrap
+ * the supplied cursor with one that will also account for header views.
+ *
+ * @param v The view to add.
+ */
+ public void addHeaderView(View v) {
+ addHeaderView(v, null, true);
+ }
+
+ public int getHeaderViewCount() {
+ return mHeaderViewInfos.size();
+ }
+
+ /**
+ * Removes a previously-added header view.
+ *
+ * @param v The view to remove
+ * @return true if the view was removed, false if the view was not a header
+ * view
+ */
+ public boolean removeHeaderView(View v) {
+ if (mHeaderViewInfos.size() > 0) {
+ boolean result = false;
+ ListAdapter adapter = getAdapter();
+ if (adapter != null && ((HeaderViewGridAdapter) adapter).removeHeader(v)) {
+ result = true;
+ }
+ removeFixedViewInfo(v, mHeaderViewInfos);
+ return result;
+ }
+ return false;
+ }
+
+ private void removeFixedViewInfo(View v, ArrayList<FixedViewInfo> where) {
+ int len = where.size();
+ for (int i = 0; i < len; ++i) {
+ FixedViewInfo info = where.get(i);
+ if (info.view == v) {
+ where.remove(i);
+ break;
+ }
+ }
+ }
+
+ @Override
+ public void setAdapter(ListAdapter adapter) {
+ if (mHeaderViewInfos.size() > 0) {
+ HeaderViewGridAdapter hadapter = new HeaderViewGridAdapter(mHeaderViewInfos, adapter);
+ int numColumns = getNumColumns();
+ if (numColumns > 1) {
+ hadapter.setNumColumns(numColumns);
+ }
+ super.setAdapter(hadapter);
+ } else {
+ super.setAdapter(adapter);
+ }
+ }
+
+ private class FullWidthFixedViewLayout extends FrameLayout {
+ public FullWidthFixedViewLayout(Context context) {
+ super(context);
+ }
+
+ @Override
+ protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
+ int targetWidth = HeaderGridView.this.getMeasuredWidth()
+ - HeaderGridView.this.getPaddingLeft()
+ - HeaderGridView.this.getPaddingRight();
+ widthMeasureSpec = MeasureSpec.makeMeasureSpec(targetWidth,
+ MeasureSpec.getMode(widthMeasureSpec));
+ super.onMeasure(widthMeasureSpec, heightMeasureSpec);
+ }
+ }
+
+ /**
+ * ListAdapter used when a HeaderGridView has header views. This ListAdapter
+ * wraps another one and also keeps track of the header views and their
+ * associated data objects.
+ *<p>This is intended as a base class; you will probably not need to
+ * use this class directly in your own code.
+ */
+ private static class HeaderViewGridAdapter implements WrapperListAdapter, Filterable {
+
+ // This is used to notify the container of updates relating to number of columns
+ // or headers changing, which changes the number of placeholders needed
+ private final DataSetObservable mDataSetObservable = new DataSetObservable();
+
+ private final ListAdapter mAdapter;
+ private int mNumColumns = 1;
+
+ // This ArrayList is assumed to NOT be null.
+ ArrayList<FixedViewInfo> mHeaderViewInfos;
+
+ boolean mAreAllFixedViewsSelectable;
+
+ private final boolean mIsFilterable;
+
+ public HeaderViewGridAdapter(ArrayList<FixedViewInfo> headerViewInfos, ListAdapter adapter) {
+ mAdapter = adapter;
+ mIsFilterable = adapter instanceof Filterable;
+
+ if (headerViewInfos == null) {
+ throw new IllegalArgumentException("headerViewInfos cannot be null");
+ }
+ mHeaderViewInfos = headerViewInfos;
+
+ mAreAllFixedViewsSelectable = areAllListInfosSelectable(mHeaderViewInfos);
+ }
+
+ public int getHeadersCount() {
+ return mHeaderViewInfos.size();
+ }
+
+ @Override
+ public boolean isEmpty() {
+ return (mAdapter == null || mAdapter.isEmpty()) && getHeadersCount() == 0;
+ }
+
+ public void setNumColumns(int numColumns) {
+ if (numColumns < 1) {
+ throw new IllegalArgumentException("Number of columns must be 1 or more");
+ }
+ if (mNumColumns != numColumns) {
+ mNumColumns = numColumns;
+ notifyDataSetChanged();
+ }
+ }
+
+ private boolean areAllListInfosSelectable(ArrayList<FixedViewInfo> infos) {
+ if (infos != null) {
+ for (FixedViewInfo info : infos) {
+ if (!info.isSelectable) {
+ return false;
+ }
+ }
+ }
+ return true;
+ }
+
+ public boolean removeHeader(View v) {
+ for (int i = 0; i < mHeaderViewInfos.size(); i++) {
+ FixedViewInfo info = mHeaderViewInfos.get(i);
+ if (info.view == v) {
+ mHeaderViewInfos.remove(i);
+
+ mAreAllFixedViewsSelectable = areAllListInfosSelectable(mHeaderViewInfos);
+
+ mDataSetObservable.notifyChanged();
+ return true;
+ }
+ }
+
+ return false;
+ }
+
+ @Override
+ public int getCount() {
+ if (mAdapter != null) {
+ return getHeadersCount() * mNumColumns + mAdapter.getCount();
+ } else {
+ return getHeadersCount() * mNumColumns;
+ }
+ }
+
+ @Override
+ public boolean areAllItemsEnabled() {
+ if (mAdapter != null) {
+ return mAreAllFixedViewsSelectable && mAdapter.areAllItemsEnabled();
+ } else {
+ return true;
+ }
+ }
+
+ @Override
+ public boolean isEnabled(int position) {
+ // Header (negative positions will throw an ArrayIndexOutOfBoundsException)
+ int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns;
+ if (position < numHeadersAndPlaceholders) {
+ return (position % mNumColumns == 0)
+ && mHeaderViewInfos.get(position / mNumColumns).isSelectable;
+ }
+
+ // Adapter
+ final int adjPosition = position - numHeadersAndPlaceholders;
+ int adapterCount = 0;
+ if (mAdapter != null) {
+ adapterCount = mAdapter.getCount();
+ if (adjPosition < adapterCount) {
+ return mAdapter.isEnabled(adjPosition);
+ }
+ }
+
+ throw new ArrayIndexOutOfBoundsException(position);
+ }
+
+ @Override
+ public Object getItem(int position) {
+ // Header (negative positions will throw an ArrayIndexOutOfBoundsException)
+ int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns;
+ if (position < numHeadersAndPlaceholders) {
+ if (position % mNumColumns == 0) {
+ return mHeaderViewInfos.get(position / mNumColumns).data;
+ }
+ return null;
+ }
+
+ // Adapter
+ final int adjPosition = position - numHeadersAndPlaceholders;
+ int adapterCount = 0;
+ if (mAdapter != null) {
+ adapterCount = mAdapter.getCount();
+ if (adjPosition < adapterCount) {
+ return mAdapter.getItem(adjPosition);
+ }
+ }
+
+ throw new ArrayIndexOutOfBoundsException(position);
+ }
+
+ @Override
+ public long getItemId(int position) {
+ int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns;
+ if (mAdapter != null && position >= numHeadersAndPlaceholders) {
+ int adjPosition = position - numHeadersAndPlaceholders;
+ int adapterCount = mAdapter.getCount();
+ if (adjPosition < adapterCount) {
+ return mAdapter.getItemId(adjPosition);
+ }
+ }
+ return -1;
+ }
+
+ @Override
+ public boolean hasStableIds() {
+ if (mAdapter != null) {
+ return mAdapter.hasStableIds();
+ }
+ return false;
+ }
+
+ @Override
+ public View getView(int position, View convertView, ViewGroup parent) {
+ // Header (negative positions will throw an ArrayIndexOutOfBoundsException)
+ int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns ;
+ if (position < numHeadersAndPlaceholders) {
+ View headerViewContainer = mHeaderViewInfos
+ .get(position / mNumColumns).viewContainer;
+ if (position % mNumColumns == 0) {
+ return headerViewContainer;
+ } else {
+ if (convertView == null) {
+ convertView = new View(parent.getContext());
+ }
+ // We need to do this because GridView uses the height of the last item
+ // in a row to determine the height for the entire row.
+ convertView.setVisibility(View.INVISIBLE);
+ convertView.setMinimumHeight(headerViewContainer.getHeight());
+ return convertView;
+ }
+ }
+
+ // Adapter
+ final int adjPosition = position - numHeadersAndPlaceholders;
+ int adapterCount = 0;
+ if (mAdapter != null) {
+ adapterCount = mAdapter.getCount();
+ if (adjPosition < adapterCount) {
+ return mAdapter.getView(adjPosition, convertView, parent);
+ }
+ }
+
+ throw new ArrayIndexOutOfBoundsException(position);
+ }
+
+ @Override
+ public int getItemViewType(int position) {
+ int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns;
+ if (position < numHeadersAndPlaceholders && (position % mNumColumns != 0)) {
+ // Placeholders get the last view type number
+ return mAdapter != null ? mAdapter.getViewTypeCount() : 1;
+ }
+ if (mAdapter != null && position >= numHeadersAndPlaceholders) {
+ int adjPosition = position - numHeadersAndPlaceholders;
+ int adapterCount = mAdapter.getCount();
+ if (adjPosition < adapterCount) {
+ return mAdapter.getItemViewType(adjPosition);
+ }
+ }
+
+ return AdapterView.ITEM_VIEW_TYPE_HEADER_OR_FOOTER;
+ }
+
+ @Override
+ public int getViewTypeCount() {
+ if (mAdapter != null) {
+ return mAdapter.getViewTypeCount() + 1;
+ }
+ return 2;
+ }
+
+ @Override
+ public void registerDataSetObserver(DataSetObserver observer) {
+ mDataSetObservable.registerObserver(observer);
+ if (mAdapter != null) {
+ mAdapter.registerDataSetObserver(observer);
+ }
+ }
+
+ @Override
+ public void unregisterDataSetObserver(DataSetObserver observer) {
+ mDataSetObservable.unregisterObserver(observer);
+ if (mAdapter != null) {
+ mAdapter.unregisterDataSetObserver(observer);
+ }
+ }
+
+ @Override
+ public Filter getFilter() {
+ if (mIsFilterable) {
+ return ((Filterable) mAdapter).getFilter();
+ }
+ return null;
+ }
+
+ @Override
+ public ListAdapter getWrappedAdapter() {
+ return mAdapter;
+ }
+
+ public void notifyDataSetChanged() {
+ mDataSetObservable.notifyChanged();
+ }
+ }
+}
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