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package com.munix.gridviewheader; /*from w ww . j av a 2 s.c o m*/ import android.content.Context; import android.database.DataSetObserver; import android.graphics.Canvas; import android.os.Build; import android.util.AttributeSet; import android.util.DisplayMetrics; import android.view.View; import android.view.ViewGroup; import android.widget.AbsListView; import android.widget.AbsListView.OnScrollListener; import android.widget.AdapterView; import android.widget.BaseAdapter; import android.widget.LinearLayout; import android.widget.ListAdapter; import android.widget.ListView; import android.widget.ListView.FixedViewInfo; import android.widget.RelativeLayout; import android.annotation.TargetApi; import android.app.Activity; /** * Componente de GridView con posibilidad de aadir un header mediante * addHeaderView(View v, Object data, boolean isSelectable); * addHeaderView(View v); * No funciona con ArrayAdapter sino con adapters extendidos de BaseAdapter * * @author munix * */ public class HeadGridView extends android.widget.GridView implements OnScrollListener, android.widget.AdapterView.OnItemClickListener { private int mScrollOfsset; private int initialTopPadding=0; private int mDisplayWidth = 0; private int headerViewHeight = 0; private ListAdapter originalAdapter; private BaseAdapter fakeAdapter; private int lastPos=0; private OnScrollListener scrollListenerFromActivity; private OnItemClickListener clickListenerFromActivity; private FixedViewInfo mHeaderViewInfo; private Boolean setFixed=false; private Boolean bringToFront=true; private int verticalSpacing=0; public HeadGridView(Context context, AttributeSet attrs, int defStyle) { super(context, attrs, defStyle); init(context); } public HeadGridView(Context context, AttributeSet attrs) { super(context, attrs); init(context); } public HeadGridView(Context context) { super(context); init(context); } private void init(Context context) { super.setOnScrollListener(this); } @Override public void onDetachedFromWindow() { if ( originalAdapter != null ) { originalAdapter.unregisterDataSetObserver( originalAdapterDataSetObserver ); } super.onDetachedFromWindow(); } @Override public void setVerticalSpacing( int spacing ) { this.verticalSpacing = spacing; super.setVerticalSpacing(spacing); } @Override public void setOnItemClickListener( OnItemClickListener l ) { clickListenerFromActivity = l; super.setOnItemClickListener(this); } @Override public void setOnScrollListener( OnScrollListener l ) { scrollListenerFromActivity = l; //Guardo la referencia del scroll para poder usar ambos super.setOnScrollListener(this); } @Override public void setAdapter( ListAdapter a ) { originalAdapter = a; fakeAdapter = new mListAdapter(); //Registramos un DataSetObserver para que cuando se produzcan cambios en el adaptador original lo podamos reflejar //en el fakeAdapter originalAdapter.registerDataSetObserver( originalAdapterDataSetObserver ); super.setAdapter(fakeAdapter); } DataSetObserver originalAdapterDataSetObserver = new DataSetObserver() { @Override public void onChanged() { fakeAdapter.notifyDataSetChanged(); } @Override public void onInvalidated() { fakeAdapter.notifyDataSetInvalidated(); } }; /** * Adaptador que recubre el original para poder dar espacio a la cabecera * @author munix * */ public class mListAdapter extends BaseAdapter { @Override public int getCount() { return originalAdapter.getCount() > 0 ? originalAdapter.getCount() + HeadGridView.this.getNumColumnsCompat() : 0; } @Override public Object getItem(int position) { return originalAdapter.getItem(position + HeadGridView.this.getNumColumnsCompat()); } @Override public long getItemId(int position) { return originalAdapter.getItemId(position + HeadGridView.this.getNumColumnsCompat()); } class InternalViewHolder { View view; } @Override public int getViewTypeCount() { return 2; } @Override public int getItemViewType( int position ) { if ( position < HeadGridView.this.getNumColumnsCompat() ) { return IGNORE_ITEM_VIEW_TYPE; }else{ return 1; } } @Override public View getView(int position, View convert, ViewGroup parent) { if ( position < HeadGridView.this.getNumColumnsCompat() ) { if ( convert == null ) { convert = new LinearLayout( getContext() ); ViewGroup.LayoutParams mParams = new LayoutParams( ViewGroup.LayoutParams.MATCH_PARENT, headerViewHeight ); mParams.height = headerViewHeight; convert.setLayoutParams( mParams ); convert.setVisibility(View.INVISIBLE); } }else{ int realPosition = position - HeadGridView.this.getNumColumnsCompat(); convert = originalAdapter.getView(realPosition, convert, parent); } return convert; } }; /** * Aade la vista al layout * @param v la vista * @param data extra data * @param isSelectable foo */ public void addHeaderView( final View v, final Object data, final boolean isSelectable) { mHeaderViewInfo = new ListView(getContext()).new FixedViewInfo(); mHeaderViewInfo.view = v; mHeaderViewInfo.data = data; mHeaderViewInfo.isSelectable = isSelectable; setupView(v); int topPadding = getPaddingTop(); if(initialTopPadding == 0){ initialTopPadding = topPadding; } headerViewHeight = v.getMeasuredHeight(); RelativeLayout parent = (RelativeLayout)getParent(); parent.addView(v, 0); if ( bringToFront ) { v.bringToFront(); } } public FixedViewInfo getHeaderView() { return mHeaderViewInfo; } private void setupView(View v) { boolean isLayedOut = !((v.getRight()==0) && (v.getLeft()==0) && (v.getTop()==0) && (v.getBottom()==0)); if(v.getMeasuredHeight() != 0 && isLayedOut ) return; if(mDisplayWidth == 0){ DisplayMetrics displaymetrics = new DisplayMetrics(); ((Activity) getContext()).getWindowManager().getDefaultDisplay().getMetrics(displaymetrics); mDisplayWidth = displaymetrics.widthPixels; } v.setLayoutParams(new LayoutParams( LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT)); v.measure(MeasureSpec.makeMeasureSpec(mDisplayWidth, MeasureSpec.AT_MOST), MeasureSpec.makeMeasureSpec(0, MeasureSpec.UNSPECIFIED)); v.layout(0, getTotalHeaderHeight(), v.getMeasuredWidth(), getTotalHeaderHeight() + v.getMeasuredHeight()); } /** * Aade la vista al layout * @param v */ public void addHeaderView(View v) { this.addHeaderView(v, null, false); } /** * Nos indica si la cabecera se pinta por delante o por detrs del scroll de la lista * @return boolean */ public Boolean isInFront() { return bringToFront; } /** * Define si la cabecera se pinta por delante del scroll o si el scroll va por encima y la cabecera est fija * @param Boolean isInFront */ public void setIsInFront( Boolean isInFront ) { bringToFront = isInFront; } /** * Permite cambiar entre una cabecera fija o scrollable * @param Boolean fixed */ public void setFixedHeader( Boolean fixed ) { this.setFixed = fixed; } private void drawHeaders() { if ( mHeaderViewInfo != null ) { int startPos = -mScrollOfsset; //Para evitar ciclos infinitos de onDraw / drawHeaders porque si en onDraw le pongo el topMargin efecta //repintado, entonces llama a drawHeaders y as.... if ( lastPos != startPos && !setFixed && bringToFront) { if ( mScrollOfsset <= headerViewHeight ) { RelativeLayout.LayoutParams mParams = (android.widget.RelativeLayout.LayoutParams)mHeaderViewInfo.view.getLayoutParams(); mParams.topMargin = startPos; mHeaderViewInfo.view.setLayoutParams(mParams); mHeaderViewInfo.view.setVisibility( View.VISIBLE ); }else{ mHeaderViewInfo.view.setVisibility( View.GONE ); } } lastPos = startPos; } } @Override protected void onDraw(Canvas canvas) { if ( fakeAdapter != null ) { drawHeaders(); } super.onDraw(canvas); } @Override protected void dispatchDraw(Canvas canvas) { super.dispatchDraw(canvas); } private int getTotalHeaderHeight() { return headerViewHeight; } private int getNumColumnsCompat() { if (Build.VERSION.SDK_INT >= 11) { return getNumColumnsCompat11(); } else { int columns = 0; int children = getChildCount(); if (children > 0) { int width = getChildAt(0).getMeasuredWidth(); if (width > 0) { columns = getWidth() / width; } } return columns > 0 ? columns : AUTO_FIT; } } @TargetApi(Build.VERSION_CODES.HONEYCOMB) private int getNumColumnsCompat11() { return getNumColumns(); } private int getVerticalSpacingCompat() { if (Build.VERSION.SDK_INT >= 16) { return getVerticalSpacingCompat16(); }else{ return this.verticalSpacing; } } @TargetApi(Build.VERSION_CODES.JELLY_BEAN) private int getVerticalSpacingCompat16() { return getVerticalSpacing(); } @Override public void onScroll(AbsListView view, int firstVisibleItem, int visibleItemCount, int totalItemCount) { if(this.getAdapter()!=null){ int count = this.getChildCount(); int totalHeaderHeight = getTotalHeaderHeight(); if (count > this.getNumColumnsCompat()) { View child = this.getChildAt(this.getNumColumnsCompat()); if (child != null) { mScrollOfsset = ((firstVisibleItem / this.getNumColumnsCompat()) * child.getMeasuredHeight()) + totalHeaderHeight - child.getTop() + this.getVerticalSpacingCompat(); } } } if ( scrollListenerFromActivity != null ) { scrollListenerFromActivity.onScroll(view, firstVisibleItem, visibleItemCount, totalItemCount); } } /** * Elimina la cabecera */ public void removeHeaderView() { if (mHeaderViewInfo != null) { RelativeLayout parent = (RelativeLayout)this.getParent(); parent.removeView( mHeaderViewInfo.view ); super.setAdapter(originalAdapter); } } @Override public void onScrollStateChanged(AbsListView view, int scrollState) { if ( scrollListenerFromActivity != null ) { scrollListenerFromActivity.onScrollStateChanged(view, scrollState); } } @Override public void onItemClick(AdapterView<?> adapter, View view, int position, long id) { if ( clickListenerFromActivity != null ) { clickListenerFromActivity.onItemClick(adapter, view, position - HeadGridView.this.getNumColumnsCompat(), id); } } }