Я попытался выполнить обратный инжиниринг gridview из примера, найденного здесь:
https://github.com/liaohuqiu/android-GridViewWithHeaderAndFooter
используя его исходный код, найденный здесь:
https://github.com/liaohuqiu/android-cube-app/blob/master/src/in/srain/cube/demo/ui/fragment/GridViewWithHeaderAndFooterFragment.java#L89
, но при попытке отобразить изображения в ней постоянно появляется ошибка приведения.
Я хотел бы научиться делать это сам, потому что его код падает, когда я пытаюсь загрузить изображения с помощью glide.
Вот код сетки, который у меня есть:
package customgridapp.customgridview;
import android.annotation.SuppressLint;
import android.content.Context;
import android.database.DataSetObservable;
import android.database.DataSetObserver;
import android.os.Build;
import android.util.AttributeSet;
import android.util.Log;
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;
public class TestFooterGridView extends GridView{
private static final String TAG = "TestFooterGridView";
/**
* 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 ArrayList<FixedViewInfo> mFooterViewInfos = new ArrayList<FixedViewInfo>();
private int mRequestedNumColumns;
private int mNumColmuns = 1;
private void initHeaderGridView() {
super.setClipChildren(false);
}
public TestFooterGridView(Context context) {
super(context);
initHeaderGridView();
}
public TestFooterGridView(Context context, AttributeSet attrs) {
super(context, attrs);
initHeaderGridView();
}
public TestFooterGridView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
initHeaderGridView();
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
if (mRequestedNumColumns != AUTO_FIT) {
mNumColmuns = mRequestedNumColumns;
}
if (mNumColmuns <= 0) {
mNumColmuns = 1;
}
ListAdapter adapter = getAdapter();
if (adapter != null && adapter instanceof FooterViewGridAdapter) {
((FooterViewGridAdapter) 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 HeaderFooterGridView 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 FooterViewGridAdapter)) {
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) {
((FooterViewGridAdapter) adapter).notifyDataSetChanged();
}
}
/**
* Add a fixed view to appear at the bottom of the grid. If addFooterView 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 HeaderFooterGridView 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 addFooterView(View v, Object data, boolean isSelectable) {
ListAdapter adapter = getAdapter();
if (adapter != null && !(adapter instanceof FooterViewGridAdapter)) {
throw new IllegalStateException(
"Cannot add footer 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;
mFooterViewInfos.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) {
((FooterViewGridAdapter) adapter).notifyDataSetChanged();
}
}
/**
* Add a fixed view to appear at the bottom of the grid. If addFooterView 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 HeaderFooterGridView can wrap
* the supplied cursor with one that will also account for header views.
*
* @param v The view to add.
*/
public void addFooterView(View v) {
addFooterView(v, null, 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 || mFooterViewInfos.size() > 0) {
FooterViewGridAdapter hadapter = new FooterViewGridAdapter(mFooterViewInfos, 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 = TestFooterGridView.this.getMeasuredWidth()
- TestFooterGridView.this.getPaddingLeft()
- TestFooterGridView.this.getPaddingRight();
widthMeasureSpec = MeasureSpec.makeMeasureSpec(targetWidth,
MeasureSpec.getMode(widthMeasureSpec));
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
@Override
public void setNumColumns(int numColumns) {
super.setNumColumns(numColumns);
// Store specified value for less than Honeycomb.
mRequestedNumColumns = numColumns;
}
@Override
@SuppressLint("NewApi")
public int getNumColumns() {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
return super.getNumColumns();
}
// Return value for less than Honeycomb.
return mNumColmuns;
}
/**
* ListAdapter used when a HeaderFooterGridView 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 FooterViewGridAdapter 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> mFooterViewInfos;
boolean mAreAllFixedViewsSelectable;
private final boolean mIsFilterable;
public FooterViewGridAdapter(ArrayList<FixedViewInfo> footerViewInfos, ListAdapter adapter) {
mAdapter = adapter;
mIsFilterable = adapter instanceof Filterable;
if (footerViewInfos == null) {
throw new IllegalArgumentException("footerViewInfos cannot be null");
}
mFooterViewInfos = footerViewInfos;
mAreAllFixedViewsSelectable = areAllListInfosSelectable(mFooterViewInfos);
}
public int getHeadersCount() {
return 0;
}
public int getFootersCount() {
return mFooterViewInfos.size();
}
@Override
public boolean isEmpty() {
return (mAdapter == null || mAdapter.isEmpty()) && getHeadersCount() == 0 && getFootersCount() == 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 removeFooter(View v) {
for (int i = 0; i < mFooterViewInfos.size(); i++) {
FixedViewInfo info = mFooterViewInfos.get(i);
if (info.view == v) {
mFooterViewInfos.remove(i);
mAreAllFixedViewsSelectable = areAllListInfosSelectable(mFooterViewInfos);
mDataSetObservable.notifyChanged();
return true;
}
}
return false;
}
@Override
public int getCount() {
if (mAdapter != null) {
final int lastRowItemCount = (mAdapter.getCount() % mNumColumns);
final int emptyItemCount = ((lastRowItemCount == 0) ? 0 : mNumColumns - lastRowItemCount);
return (getHeadersCount() * mNumColumns) + mAdapter.getCount() + emptyItemCount + (getFootersCount() * mNumColumns);
} else {
return (getHeadersCount() * mNumColumns) + (getFootersCount() * 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
if (position < numHeadersAndPlaceholders + mAdapter.getCount()) {
final int adjPosition = position - numHeadersAndPlaceholders;
int adapterCount = 0;
if (mAdapter != null) {
adapterCount = mAdapter.getCount();
if (adjPosition < adapterCount) {
return mAdapter.isEnabled(adjPosition);
}
}
}
// Empty item
final int lastRowItemCount = (mAdapter.getCount() % mNumColumns);
final int emptyItemCount = ((lastRowItemCount == 0) ? 0 : mNumColumns - lastRowItemCount);
if (position < numHeadersAndPlaceholders + mAdapter.getCount() + emptyItemCount) {
// return false;
return (position % mNumColumns == 0)
&& mFooterViewInfos.get((position - numHeadersAndPlaceholders - mAdapter.getCount() - emptyItemCount) / mNumColumns).isSelectable;
}
// Footer
int numFootersAndPlaceholders = getFootersCount() * mNumColumns;
if (position < numHeadersAndPlaceholders + mAdapter.getCount() + emptyItemCount + numFootersAndPlaceholders) {
return (position % mNumColumns == 0)
&& mFooterViewInfos.get((position - numHeadersAndPlaceholders - mAdapter.getCount() - emptyItemCount) / mNumColumns).isSelectable;
}
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 0; //mHeaderViewInfos.get(position / mNumColumns).data;
}
return null;
}
// Adapter
if (position < numHeadersAndPlaceholders + mAdapter.getCount()) {
final int adjPosition = position - numHeadersAndPlaceholders;
int adapterCount = 0;
if (mAdapter != null) {
adapterCount = mAdapter.getCount();
if (adjPosition < adapterCount) {
return mAdapter.getItem(adjPosition);
}
}
}
// Empty item
final int lastRowItemCount = (mAdapter.getCount() % mNumColumns);
Log.e(TAG, "Lastrowitemcount:" + lastRowItemCount);
final int emptyItemCount = ((lastRowItemCount == 0) ? 0 : mNumColumns - lastRowItemCount);
Log.e(TAG, "emptyitemcount:" + emptyItemCount);
if (position < numHeadersAndPlaceholders + mAdapter.getCount() + emptyItemCount) {
/*return null;*/
return mFooterViewInfos.get((position - numHeadersAndPlaceholders - mAdapter.getCount() - emptyItemCount) / mNumColumns).data;
}
// Footer
int numFootersAndPlaceholders = getFootersCount() * mNumColumns;
if (position < numHeadersAndPlaceholders + mAdapter.getCount() + emptyItemCount + numFootersAndPlaceholders) {
if (position % mNumColumns == 0) {
return mFooterViewInfos.get((position - numHeadersAndPlaceholders - mAdapter.getCount() - emptyItemCount) / mNumColumns).data;
}
}
throw new ArrayIndexOutOfBoundsException(position);
}
@Override
public long getItemId(int position) {
int numHeadersAndPlaceholders = getHeadersCount() * mNumColumns;
if (mAdapter != null) {
if (position >= numHeadersAndPlaceholders && position < numHeadersAndPlaceholders + mAdapter.getCount()) {
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 null; //headerViewContainer;
} else {
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
// TODO Current implementation may not be enough in the case of 3 or more column. May need to be careful on the INVISIBLE View height.
if (position < numHeadersAndPlaceholders + mAdapter.getCount()) {
final int adjPosition = position - numHeadersAndPlaceholders;
int adapterCount = 0;
if (mAdapter != null) {
adapterCount = mAdapter.getCount();
if (adjPosition < adapterCount) {
convertView = mAdapter.getView(adjPosition, convertView, parent);
convertView.setVisibility(View.VISIBLE);
return convertView;
}
}
}
// Empty item
final int lastRowItemCount = (mAdapter.getCount() % mNumColumns);
Log.e(TAG, "Lastrowitemcount:" + lastRowItemCount);
final int emptyItemCount = ((lastRowItemCount == 0) ? 0 : mNumColumns - lastRowItemCount);
Log.e(TAG, "Emptyitemcount:" + emptyItemCount);
if (position < numHeadersAndPlaceholders + mAdapter.getCount() + emptyItemCount) {
// 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.
// TODO Current implementation may not be enough in the case of 3 or more column. May need to be careful on the INVISIBLE View height.
convertView = mAdapter.getView(mAdapter.getCount() - 1, convertView, parent);
convertView.setVisibility(View.INVISIBLE);
return convertView;
}
// Footer
int numFootersAndPlaceholders = getFootersCount() * mNumColumns;
if (position < numHeadersAndPlaceholders + mAdapter.getCount() + emptyItemCount + numFootersAndPlaceholders) {
View footerViewContainer = mFooterViewInfos
.get((position - numHeadersAndPlaceholders - mAdapter.getCount() - emptyItemCount) / mNumColumns).viewContainer;
if (position % mNumColumns == 0) {
return footerViewContainer;
} else {
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(footerViewContainer.getHeight());
return convertView;
}
}
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 && position < numHeadersAndPlaceholders + mAdapter.getCount() + (mNumColumns - (mAdapter.getCount() % mNumColumns))) {
int adjPosition = position - numHeadersAndPlaceholders;
int adapterCount = mAdapter.getCount();
if (adjPosition < adapterCount) {
return mAdapter.getItemViewType(adjPosition);
} else if (adapterCount != 0 && mNumColumns != 1) {
return mAdapter.getItemViewType(adapterCount - 1);
}
}
int numFootersAndPlaceholders = getFootersCount() * mNumColumns;
if (mAdapter != null && position < numHeadersAndPlaceholders + mAdapter.getCount() + numFootersAndPlaceholders) {
return mAdapter != null ? mAdapter.getViewTypeCount() : 1;
}
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();
}
}
}
Я попытался понять его код, удалив любой код, относящийся к заголовкам, и только глядя на то, что он делает с нижними колонтитулами.
Вкратце: как мне добавить нижний колонтитул в сетку с тремя столбцами?
Что мне нужно?