Clean up saving of view history.

1 files changed, 53 insertions, 32 deletions

diff --git a/src/org/madore/android/unicodeMap/UnicodeMapActivity.java b/src/org/madore/android/unicodeMap/UnicodeMapActivity.java
index 74dca91..a13f73a 100644
--- a/src/org/madore/android/unicodeMap/UnicodeMapActivity.java
+++ b/src/org/madore/android/unicodeMap/UnicodeMapActivity.java
@@ -27,15 +27,20 @@ public final class UnicodeMapActivity extends ListActivity {
 
     protected UnicodeDatabase db;
 
-    protected final List<UnicodeDisplayable> rootList
-	= new ArrayList<UnicodeDisplayable>(200);
+    protected class ViewHistory {
+	public final UnicodeArrayAdapter adapter;
+	public final int selPosition;
+	public final int yOffset;
+	public ViewHistory(UnicodeArrayAdapter adapter,
+			   int selPosition, int yOffset) {
+	    this.adapter = adapter;
+	    this.selPosition = selPosition;
+	    this.yOffset = yOffset;
+	}
+    }
 
-    protected final List<UnicodeArrayAdapter> stack
-	= new ArrayList<UnicodeArrayAdapter>(10);
-    protected final List<Integer> positionStack
-	= new ArrayList<Integer>(10);
-    protected final List<Integer> positionYStack
-	= new ArrayList<Integer>(10);
+    protected final List<ViewHistory> historyStack
+	= new ArrayList<ViewHistory>(10);
 
     EditText textForm;
 
@@ -67,6 +72,37 @@ public final class UnicodeMapActivity extends ListActivity {
 	thr.start();
     }
 
+    protected void saveView(View selView, int selPosition) {
+	final ListView lv = getListView();
+	lv.clearTextFilter();
+	final UnicodeArrayAdapter adapter
+	    = (UnicodeArrayAdapter) lv.getAdapter();
+	final int yOffset;
+	if ( selView != null )
+	    yOffset = selView.getTop();
+	else
+	    yOffset = 0;
+	historyStack.add(new ViewHistory(adapter, selPosition, yOffset));
+    }
+
+    protected void saveView() {
+	final ListView lv = getListView();
+	lv.clearTextFilter();
+	final UnicodeArrayAdapter adapter
+	    = (UnicodeArrayAdapter) lv.getAdapter();
+	int position = lv.getSelectedItemPosition();
+	int position0 = lv.getFirstVisiblePosition();
+	if ( position == AdapterView.INVALID_POSITION )
+	    position = position0;
+	View view = lv.getChildAt(position-position0);
+	final int yOffset;
+	if ( view != null )
+	    yOffset = view.getTop();
+	else
+	    yOffset = 0;
+	historyStack.add(new ViewHistory(adapter, position, yOffset));
+    }
+
     protected class MapItemClickListener
 	implements AdapterView.OnItemClickListener,
 		   AdapterView.OnItemLongClickListener {
@@ -86,12 +122,7 @@ public final class UnicodeMapActivity extends ListActivity {
 		UnicodeArrayAdapter adapter
 		    = new UnicodeArrayAdapter(UnicodeMapActivity.this,
 					      list);
-		stack.add(adapter);
-		positionStack.add(position);
-		if ( view != null )
-		    positionYStack.add(view.getTop());
-		else
-		    positionYStack.add(0);
+		saveView(view, position);
 		setListAdapter(adapter);
 	    } else
 		throw new AssertionError("unknown UnicodeDisplayable");
@@ -159,11 +190,12 @@ public final class UnicodeMapActivity extends ListActivity {
 	final boolean needPopulate = db.needPopulate();
 	if ( needPopulate )
 	    launchPopulation();
+	List<UnicodeDisplayable> rootList
+	    = new ArrayList<UnicodeDisplayable>(UnicodeCharacter.Range.values().length);
 	for ( UnicodeCharacter.Range rng : UnicodeCharacter.Range.values() )
 	    rootList.add(rng);
 	UnicodeArrayAdapter rootAdapter
 	    = new UnicodeArrayAdapter(this, rootList);
-	stack.add(rootAdapter);
 	setListAdapter(rootAdapter);
 	final ClipboardManager cmgr
 	    = (ClipboardManager)getSystemService(Context.CLIPBOARD_SERVICE);
@@ -197,18 +229,7 @@ public final class UnicodeMapActivity extends ListActivity {
 	UnicodeArrayAdapter adapter
 	    = new UnicodeArrayAdapter(UnicodeMapActivity.this,
 				      list);
-	stack.add(adapter);
-	final ListView lv = getListView();
-	int position = lv.getSelectedItemPosition();
-	int position0 = lv.getFirstVisiblePosition();
-	if ( position == AdapterView.INVALID_POSITION )
-	    position = position0;
-	positionStack.add(position);
-	View view = lv.getChildAt(position-position0);
-	if ( view != null )
-	    positionYStack.add(view.getTop());
-	else
-	    positionYStack.add(0);
+	saveView();
 	setListAdapter(adapter);
 	if ( overflowed ) {
 	    String str = getResources().getString(R.string.list_too_long);
@@ -258,12 +279,12 @@ public final class UnicodeMapActivity extends ListActivity {
 
     @Override
     public boolean onKeyDown(int keyCode, KeyEvent event) {
-	if ( ( keyCode == KeyEvent.KEYCODE_BACK ) && stack.size() > 1 ) {
+	if ( ( keyCode == KeyEvent.KEYCODE_BACK )
+	     && historyStack.size() > 0 ) {
 	    final ListView lv = getListView();
-	    stack.remove(stack.size()-1);
-	    setListAdapter(stack.get(stack.size()-1));
-	    lv.setSelectionFromTop(positionStack.remove(positionStack.size()-1),
-				   positionYStack.remove(positionYStack.size()-1));
+	    ViewHistory saved = historyStack.remove(historyStack.size()-1);
+	    setListAdapter(saved.adapter);
+	    lv.setSelectionFromTop(saved.selPosition, saved.yOffset);
 	    return true;
 	} else if ( keyCode == KeyEvent.KEYCODE_SEARCH ) {
 	    querySearch();