From 2e45fd060ca623a3f28858eabd17be891b4fba89 Mon Sep 17 00:00:00 2001 From: Bobby Georgescu Date: Thu, 28 Mar 2013 15:41:32 -0700 Subject: Add HeaderGridView implementation Change-Id: Id0e699be0e40310c4919a9d55503edb9b07d4b58 --- src/com/android/photos/views/HeaderGridView.java | 466 +++++++++++++++++++++++ 1 file changed, 466 insertions(+) create mode 100644 src/com/android/photos/views/HeaderGridView.java (limited to 'src/com/android/photos') diff --git a/src/com/android/photos/views/HeaderGridView.java b/src/com/android/photos/views/HeaderGridView.java new file mode 100644 index 000000000..45a5eaf73 --- /dev/null +++ b/src/com/android/photos/views/HeaderGridView.java @@ -0,0 +1,466 @@ +/* + * 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; + /** true if the fixed view should be selectable in the grid */ + public boolean isSelectable; + } + + private ArrayList mHeaderViewInfos = new ArrayList(); + + 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. + *

+ * 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. + *

+ * 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 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. + *

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 mHeaderViewInfos; + + boolean mAreAllFixedViewsSelectable; + + private final boolean mIsFilterable; + + public HeaderViewGridAdapter(ArrayList 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 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(); + } + } +} -- cgit v1.2.3